Corrective contact lenses and related methods

Abstract

The present disclosure provides an orthocorneal lens (201) and a method for manufacturing such a lens (201). The specification discloses an orthocorneal lens (210) having a correction region (206) that reduces the curvature of the central portion of the cornea, an annular treatment recess (208) that introduces proximal defocus into the peripheral portion of the cornea, and an accommodation region (210) that adjusts for the myopic defocus introduced by the annular treatment recess (208).

Description

[Technical Field]

[0001] The present invention relates to orthokeratology contact lenses and methods, particularly but not exclusively to contact lenses for reshaping the cornea of ​​the eye to provide optical correction for and slow the progression of myopia, and also to methods for making such lenses. [Background technology]

[0002] Myopia (also known as near-sightedness or short-sightedness in English, both of which are commonly translated as "myopia" in Japanese) is an eye condition primarily caused by an elongation of the eye's axial length. Uncorrected myopia causes incoming light from distant objects to be focused at a location in front of the retina. Once light enters the eye, it converges toward a focal plane located at the retina, then diverges beyond this, becoming defocused upon reaching the retina. As a result, a nearsighted person (myopic person) is unable to focus on distant objects.

[0003] Many people use contact lenses to correct myopia. Conventional contact lenses for correcting myopia reduce the convergence of light passing through the contact lens, shifting the image plane onto the retina. Distance vision improves only if the eye's refractive power plus the lens' refractive power ("power" can also be referred to as "diopter," "power," or simply "degree," and these terms are used interchangeably herein) is reduced with contact or spectacle lenses or if the retina is reshaped. Furthermore, while conventional contact lenses correct the mismatch between optical power and axial length, they do not treat the abnormal eye size that is the underlying cause of myopia.

[0004] Decades ago, it was suggested that undercorrection, i.e., moving the focal point closer to the retina but not completely onto it, could be used to slow or prevent the progression of myopia in children or young people. However, the inevitable consequence of this approach is a decrease in distance vision compared to that achieved with lenses that completely correct myopia. Furthermore, the effectiveness of undercorrection in controlling myopia progression is now considered questionable. A relatively recent approach to providing a focused image at the retina while simultaneously slowing progressive eye growth is to use lenses that have both one or more areas that provide complete correction of distance vision and one or more areas that are undercorrected or intentionally induce myopic defocus. It has been suggested that this approach can prevent or slow the progression or progression of myopia in children or young people while still providing good distance vision.

[0005] In lenses having a zone providing myopic defocus, the zone providing full correction of distance vision is commonly referred to as the base zone, and the zone providing undercorrection is commonly referred to as the myopic defocus zone or add zone (because its power or refractive power, expressed in diopters, is more positive (+) or less negative (-) than that of the distance-correcting base zone). The surface (typically the anterior surface) of the add zone has a radius of curvature that is smaller than that of the distance zone, thus providing a greater positive or less negative refractive power to the eye. The add zone is designed to focus light anterior to (i.e., in front of) the retina when the distance-correcting optic focuses light at or near the retina.

[0006] One known type of contact lens for reducing myopia progression is the dual-focus (i.e., "bifocal") contact lens commercially available under the name MISIGHT (CooperVision, Inc.), as shown in FIG. 1. Lens 100 has a central correction zone 101 and two additional annular correction zones 102 and 104. The correction zones 101, 102, and 104 are distance-power regions that provide stable corrective power or base power throughout each zone. The lens also has two annular treatment zones 106 and 108. Each treatment zone 106 and 108 is positioned between the two correction zones 101, 102, and 102, 104, respectively. The treatment zones 106 and 108 provide add power or myopic defocus. The diameters of the correction zones 101, 102, 104 and the treatment zones 106, 108 are well-defined, and the refractive power is stable throughout each zone. This dual focus lens differs from bifocal or multifocal contact lenses designed to improve presbyopic vision in that the dual focus lens has specific optical dimensions that allow individuals with accommodation to use distance correction (i.e., base power) to see both distant and near objects. The treatment zones of the dual focus lens, which have add power, also provide myopically defocused images at both distance and near distances.

[0007] MISIGHT lenses have been shown to correct myopia and slow the progression of myopia in children (Chamberlain et al., Optometry and Vision Sciences, 2009). Optometry and Vision Science )”, 2019, 96(8): 556-557, Chamberlain et al., “Optometry and Vision Science ( Optometry and Vision Science) 2022, 99(3):204-212), but myopia correction and treatment is only achieved when the lenses are worn. An alternative to dual focus contact lenses to provide optical correction of current myopia and slow further progression is orthokeratology. Studies have shown that overnight wear of orthokeratology lenses can provide optical correction of myopia (Mountford et al., Orthokeratology: Principles and Practice, 2022, 99(3):204-212). Orthokeratology: principles and practice ), Butterworth-Heinemann Medical, 2004), and these corrective corneal lenses may also be effective in slowing the progression of myopia (Cho et al., Current Eye Research, Current Eye Research ) 2005, 30(1):71 / 80. Corrective corneal lenses (commonly known as "ortho-K" lenses) correct myopia by reshaping the corneal surface and changing the curvature of the cornea in a defined area. Thus, corrective corneal lenses produce a physical change in the myopic eye that improves vision.

[0008] Corrective contact lenses have a central region comprised of a posterior surface with a small curvature or flat profile designed to flatten the curvature of the cornea. When the lens is worn, the central corrective region exerts pressure or compression on the epithelial layer of the cornea, which redistributes corneal tissue and / or fluid from the central to the peripheral cornea. This redistribution compresses the apex of the cornea, thereby reducing its curvature. In myopic eyes, where the cornea's curvature is too steep to focus light onto the retina, reducing the corneal curvature shifts the focus of light onto the retina, correcting myopia and improving distance vision. Examples of corrective lenses are disclosed in U.S. Patent Nos. 6,543,897 and 6,652,095. Although these specifications disclose that orthokeratology lenses can correct myopia, hyperopia, and already advanced presbyopia, they do not disclose that such lenses are suitable for treating or slowing the progression of myopia.

[0009] Corrective lenses gradually reshape the cornea and are therefore typically worn overnight. After several hours of wear, the cornea is reshaped to correct myopia, allowing the user to remove the corrective lenses, for example, in the morning. After the lenses are removed, the cornea retains its new shape for several hours, allowing the user to focus on distant objects without the need for corrective lenses. Corrective lenses offer an advantage over other contact lenses in that vision remains corrected even when the lenses are not worn. During the day on the day the lenses are removed, the cornea partially returns to its original shape. Therefore, the user must wear the corrective lenses every night to maintain the desired shape of the central cornea.

[0010] In addition to the correction zone, the orthokeratology lens also includes an annular arcuate region (sometimes called a "reverse curve" or "return zone") surrounding the central correction zone of the lens. This region is located on the posterior surface of the lens and is a concave portion that accommodates an increase in tissue volume in a region of the cornea. This increase in tissue volume in this region of the cornea results from the redistribution of corneal tissue and / or fluid directed toward the peripheral portion of the cornea by the central correction zone of the lens, which increases the curvature of the corneal epithelial layer. Thus, the annular arcuate region allows for the movement of corneal tissue and / or fluid away from the central region of the cornea, thereby helping to flatten the central portion of the cornea. An unavoidable consequence of the annular arcuate region is that the peripheral portion of the cornea into which tissue and fluid are redistributed is a single annular portion of add plus power or myopic defocus, which surrounds the central flattened region of the cornea.

[0011] Although orthokeratology lenses, in contrast to MISIGHT-type lenses, have been found to be effective in correcting myopia, the corrected and add-plus power areas of the cornea created by orthokeratology lenses are not clearly defined. The correction provided by the correction zone of an orthokeratology lens is not constant throughout the central portion of the cornea. Furthermore, providing a constant add power throughout the peripheral annular region of the cornea that is aligned with the annular arcuate region is challenging, and the resulting ring of add power in the cornea has traditionally been considered an inevitable consequence of central flattening, not a special design feature with a controlled optic. The limited control over the myopic defocus and correction area created in the cornea by orthokeratology lenses currently limits their effectiveness in correcting existing myopia and slowing its future progression.

[0012] Another problem with orthokeratology lenses is that the diameter of the corrected central portion of the cornea and the add-plus power provided to the peripheral portion of the cornea vary for different magnitudes of correction. Generally, the greater the degree of myopia, the smaller the diameter of the central correction of the cornea caused by the correction region of the lens and the greater the ocular optical add provided to the peripheral portion of the cornea by the surrounding annular arcuate region. This significantly limits the degree of myopia that can be treated with conventional orthokeratology lenses and prevents the treatment from providing a controlled level of myopia control signal. In contrast, the MISIGHT lens has a constant central correction zone with a fixed diameter of 3.6 mm, even though the level of myopia is treated and a well-controlled and stable myopia control treatment power is obtained. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] U.S. Patent No. 6,652,095 [Patent Document 2] U.S. Patent No. 6,543,897 [Non-patent literature]

[0014] [Non-Patent Document 1] Chamberlain et al., Optometry and Vision Science, 2019, 96(8):556-557 [Non-patent document 2] Chamberlain et al., Optometry and Vision Science, 2022, 99(3):204-212 [Non-patent document 3] Mountford et al., "Orthokeratology: principles and practice," Butterworth-Heinemann Medica, 2004 [Non-patent document 4] Cho et al., Current Eye Research, 2005, 30(1):71 / 80 Summary of the Invention [Problem to be solved by the invention]

[0015] The present invention seeks to provide an orthokeratological lens that provides control over the diameter of the corrected central portion of the cornea, regardless of the level of myopia being treated. Such a lens may further provide a more consistent refractive power throughout the corrected central region of the cornea. Additionally or alternatively, such a lens may provide a well-defined region of myopic defocus in the treated cornea. [Means for solving the problem]

[0016] According to a first aspect, the present invention provides an orthokeratology contact lens for correcting and slowing the progression of myopia, which lens is set out in claim 1.

[0017] According to a second aspect, the present invention further provides a method for producing an orthokeratogenic contact lens, said method being defined in claim 10.

[0018] According to a third aspect, the present invention provides a method for manufacturing an orthokeratogenic contact lens, said method being as set forth in claim 11.

[0019] The present invention further provides a method for treating the progression of myopia, comprising the step of providing a lens according to the first aspect to a patient in need thereof, such method being as set out in claim 15.

[0020] Optional but preferred features are set out in the dependent claims.

[0021] It will, of course, be recognized that features described in connection with one aspect of the present disclosure may be incorporated into other aspects of the present disclosure, for example, a method of preparing an orthokeratological contact lens of the present disclosure may incorporate any of the features described with respect to an orthokeratological contact lens of the present invention, and vice versa.

[0022] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which: [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a plan view of a prior art dual focus lens 100. [Figure 2A] FIG. 2C is a cross-sectional view of the lens 201 of the present invention taken along line A-A′ of FIG. 2B, illustrating that the lens 201 is suitable for treating or slowing the progression of myopia in relatively highly myopic eyes. [Figure 2B] 2B is a plan view of the lens 201 shown in FIG. 2A, showing how the boundaries of each concentric zone coincide with the boundaries of the lens zones defined by changes in curvature of the posterior surface 202 of the lens. [Figure 3A] FIG. 3C is a cross-sectional view of the lens 301 of the present invention taken along line A-A′ of FIG. 3B, illustrating that the lens is suitable for treating or slowing the progression of myopia in relatively low myopic eyes. [Figure 3B] 3B is a plan view of the lens 301 shown in FIG. 3A, showing how the boundaries of each concentric zone coincide with the boundaries of the lens zones defined by changes in curvature of the posterior surface 302 of the lens. [Figure 4A]FIG. 4 is a cross-sectional view of a lens 401 of the present invention in use, in which the lens 401 is positioned on the surface of the cornea 414, with the accommodative region of the lens not shown for clarity, and arrows indicating the pressure force exerted on the cornea 414 by the central corrective region 406 of the lens 401 and the resulting flow of fluid and / or tissue from the central portion of the cornea 414 to the peripheral portion of the cornea 414. [Figure 4B] 4B is a cross-sectional view of the surface profile of the cornea 414 before and after treatment, in which the dashed line shows the surface profile of the cornea 414 before treatment with the lens 401 of FIG. 4A, and the solid line shows the area of ​​the cornea 414 having a modified surface profile following treatment with the lens 401, showing that the surface profile of the cornea 414 after treatment has a flattened and less curved central portion and a raised and more curved peripheral portion compared to the surface profile of the cornea 414 before treatment. [Figure 5] 4A is a cross-sectional view of the lens 401 of FIG. 4A, showing that regions of the lens 401 (corrective region 406, annular treatment recess 408, and fitting region 412) are shown and that the dimensions of these regions (width, curvature, depth, asymmetry, and symmetry) shown can be adjusted to control the movement of corneal tissue and fluid, thus inducing a particular profile in the cornea to be treated as shown; also, for clarity, the accommodative regions of the lens 401 are not shown, with arrows indicating the movement of fluid and / or tissue within the cornea 414. [Figure 6] FIG. 4B is a cross-sectional view of the lens 401 of FIG. 4A showing the dimensions of the adjustable annular therapeutic recess 408, and for clarity, not showing the accommodation region of the lens 401, with the left side of the lens 401 showing the change in width of the annular therapeutic recess 408 and the right side of the lens showing the change in slope or asphericity of the annular therapeutic recess 408, and arrows indicating fluid and / or tissue movement within the cornea 414. [Figure 7]FIG. 4B is a cross-sectional view of the lens 401 of FIG. 4A showing different dimensions of the adjustable annular therapeutic recess 408, and for clarity, the adjustable region of the lens 401 is not shown, the left side of the lens 401 shows the change in curvature and tilt of the annular therapeutic recess 408, and the right side of the lens 401 shows the change in position of the annular therapeutic recess 408, with arrows indicating fluid and / or tissue movement within the cornea 414. [Figure 8] 4B is a cross-sectional view of the lens 401 of FIG. 4A showing the dimensions of the adjustable accommodative region 410, with the left side of the lens 401 showing the change in curvature and width of the accommodative region 410 and the right side of the lens 401 showing the change in tilt or asphericity and symmetry of the accommodative region 410, with arrows indicating fluid and / or tissue movement within the cornea. [Figure 9] FIG. 5 illustrates a method 500 for manufacturing a lens of the present invention. [Figure 10] FIG. 6 illustrates another method 600 for manufacturing a lens of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] According to a first aspect of the present disclosure, a corneal orthodontic contact lens is disclosed. The corneal orthodontic contact lens is for treating or slowing the progression of myopia by reshaping a portion of the cornea in a myopic eye. The lens has a posterior surface that contacts the portion of the cornea to be reshaped. The posterior surface of the lens has a correction region that reduces the curvature of the central portion of the cornea. The correction region is defined by a first section of the posterior surface having a radius of curvature of 6 mm or greater. The posterior surface of the lens further has an annular therapeutic recess that creates myopic defocus in the peripheral portion of the cornea. The annular therapeutic recess is defined by a second section of the posterior surface that extends radially outward from the periphery of the correction region and has a radius of curvature smaller than that of the first section, the radius of curvature of the second section being configured such that the annular therapeutic recess creates myopic defocus of at least +1D in the peripheral portion of the cornea. The posterior surface of the lens has an accommodation region that adjusts for the myopic defocus created by the annular therapeutic recess. The adjustment region is defined by a third section of the posterior surface extending radially outward from the periphery of the annular treatment recess and having a radius of curvature ranging from 4.5 mm to 15 mm.

[0025] According to a second aspect, a method for manufacturing a corneal orthodontic contact lens for treating or slowing the progression of myopia by reshaping a portion of the cornea of ​​a myopic eye is disclosed. The corneal orthodontic contact lens may be a lens according to the first aspect of the present disclosure. The method includes forming a posterior surface of the lens that contacts the portion of the cornea to be reshaped. The method includes forming a first section of the posterior surface, the first section constituting a correction zone of the contact lens and having a radius of curvature of 6 mm or greater. The method further includes forming a second section of the posterior surface extending radially outward from a periphery of the correction zone. The second section constitutes an annular treatment recess and has a radius of curvature smaller than that of the first section. The radius of curvature of the second section is such that the annular treatment recess induces at least +1D of myopic defocus in the peripheral portion of the cornea. The method further includes forming a third section of the posterior surface extending radially outward from a periphery of the annular treatment recess. The third section constitutes an accommodation zone and also has a radius of curvature ranging from 4.5 mm to 15 mm. The first, second, and third sections of the posterior surface of the lens may be formed sequentially or simultaneously by the methods disclosed herein.

[0026] As used herein, "contact lens" or simply "lens" refers to an ophthalmic lens that can be worn on the anterior surface of the eye. Orthokeratology contact lenses are a type of contact lens, the properties and characteristics of which are described herein. As will be appreciated, contact lenses provide clinically acceptable on-eye movement and do not become stuck in a person's eye (one or both eyes). Contact lenses are in the form of corneal lenses (lenses that rest on the cornea of ​​the eye).

[0027] According to the present disclosure, the lenses are orthokeratological contact lenses (also referred to as "ortho-K lenses"). As will be understood, when referring to the "lenses" of the present invention, unless otherwise specified, they refer to orthokeratological contact lenses. Traditional contact lenses correct myopia by reducing the convergence of incoming light from distant objects before it reaches the eye, thereby shifting the focal point onto the retina. Thus, traditional contact lenses must be worn on the cornea to improve vision. In contrast, orthokeratological contact lenses of the present disclosure alter the optical properties of the eye itself by gradually changing or reshaping the surface profile of the patient's cornea over time. Reshaping the surface profile of the lens allows for temporary optical correction of myopia.

[0028] When worn, the disclosed orthokeratology contact lenses continuously exert pressure on selected locations on the cornea to reshape the cornea to a desired surface profile. In particular, orthokeratology contact lenses are placed on the cornea and primarily reshape the epithelial layer of the cornea by altering the distribution of fluid and / or tissue within the epithelial layer. It should be understood that references to fluid and / or tissue refer to any organic or physiological substance within the epithelial layer of the cornea that can be displaced by compressive forces applied to the surface of the cornea. For example, fluids within the epithelial layer of the cornea include water or aqueous solutions of solutes typically found within the cornea, and may further include dispersions of organic substances typically found within the cornea dissolved in aqueous solutions. Tissue may refer to cells or groups of cells typically found within the cornea. The disclosed orthokeratology contact lenses can reshape the cornea of ​​the eye, i.e., reshape the cornea with a radius of curvature that converges incoming light from distant objects before it reaches the eye, or a radius of curvature that reduces the convergence of incoming light from distant objects so that it is focused on the retina. Mechanisms are disclosed herein by which corneal fluid and / or tissue can be redistributed. The reshaped surface profile of the cornea can be maintained even after the orthokeratology contact lens is removed from contact with the cornea of ​​the eye. The reshaped surface profile of the cornea can be maintained for extended periods of time after the lens is removed from contact with the cornea of ​​the eye, such that distance vision is maintained for several hours, up to 5 hours, up to 8 hours, up to 12 hours, or up to 16 hours, or even for an entire day or multiple days. Thus, the optical correction provided by the orthokeratology contact lens is maintained in the cornea even after the lens is removed.

[0029] The orthokeratology contact lenses disclosed herein are intended to correct and treat myopia. As should be understood, correcting myopia means altering the optical properties of the eye to reduce or eliminate the myopia of the eye and also to provide adequate visual acuity without the need for corrective devices, such as traditional contact lenses or spectacle lenses. For example, an eye with myopia of -0.25D to -15D can exhibit a myopia reduction of at least 0.5D, or preferably at least 0.75D, after wearing the lenses of the present invention. Presumably, wearing the orthokeratology contact lenses every night for a week achieves a correction of myopic refractive error sufficient to eliminate the need for traditional corrective devices, such as contact lenses or spectacle lenses. Preferably, as a result of myopia correction, the eye is no longer myopic, and therefore no external visual correction (e.g., the use of spectacle lenses or contact lenses) is required for distance vision. Myopia can be corrected by the lens reducing the curvature of at least the central portion of the cornea. This can be achieved by orthokeratology contact lenses through the mechanisms described herein. As will be appreciated, myopic correction of the central portion of the cornea is necessary to correct distance vision. However, the peripheral portion of the cornea remains uncorrected, or even has increased myopia ("myopic defocus"), so that distance vision is not impeded. For example, orthokeratology contact lenses according to the present disclosure can correct myopia for the central portion of the cornea while undercorrecting myopia or adding positive refractive power to the peripheral portion of the cornea. Such undercorrection or the addition of positive power to the peripheral portion can be described as introducing myopic defocus into the eye.

[0030] As understood, treating myopia means slowing the progression of myopia. Treating myopia likely results in halting or reversing the progression of myopia. This may be particularly advantageous for children, whose myopia typically worsens as they age. Perhaps the use of orthocorneal contact lenses can prevent the onset of myopia in patients at risk of myopia. Without wishing to be bound by theory, it is believed that the myopic defocus introduced into the peripheral portion of the cornea by the orthocorneal contact lenses disclosed herein plays a role in slowing the progression of myopia or preventing its onset. The annular therapeutic recess of the orthocorneal contact lenses disclosed herein can introduce myopic defocus into the cornea by the mechanisms disclosed herein.

[0031] The disclosed orthokeratology contact lenses may be rigid (hard) contact lenses made of a hard material. The lenses may be gas-permeable hard contact lenses. The orthokeratology contact lenses may be made of polymethyl methacrylate (PMMA), copolymers of fluoromethacrylate and siloxanylstyrene, copolymers of fluorosilicone acrylate compounds, or copolymers of silicone methacrylate and fluoromethacrylate compounds. Suitable lens materials include those having the following United States Adopted Names (USAN): tisifocn A, trophocon A, paflufocn A, paflufocn B, and paflufocn C. As will be appreciated, hard lenses are particularly effective in redistributing corneal fluid and / or tissue in the epithelial layer of the cornea because their rigid structure can exert sufficient compressive forces on the corneal surface to displace fluid and / or tissue from one area of ​​the cornea to another area of ​​the cornea.

[0032] The term "lens body" refers to the bulk of a lens, and may particularly refer to a section of a lens bounded by an anterior surface and a posterior surface. The lens body may be formed from multiple lens layers. The term "lens layer" refers to a region of lens material that forms at least a section of the lens body. When multiple lens layers are present, each lens layer has a thickness that is less than the thickness of the lens body. Optionally, the lens body comprises a lens layer attached to at least one other layer. For example, multiple layers, such as at least two or at least three layers, may be stacked to form the lens body. When multiple lens layers are present, the lens layers may be made of the same or different materials. Optionally, at least two of the lens layers may be formed of the same material and at least one lens layer may be formed of a different material. When a lens body has multiple lens layers, there will likely be indistinguishable boundaries between the layers. For example, the lens body may be formed by curing a bulk material to form a first layer, layering another material on the first layer, and then curing that to form a second layer. When the first and second layers are formed of dissimilar materials, it will be apparent that there will be an interface where the chemical composition of the materials changes from one layer to the other. When the first and second layers are formed of the same material, different physical properties may exist between the layers, such as different optical properties or crystallinity at the interface between the lens layers. It will be understood that when a lens is made of two or more lens layers, the posterior surface of the lens refers to the posterior surface of the lowest layer, i.e., the layer that contacts the eye when the lens is worn. The anterior surface of the lens, when the lens is composed of multiple layers, will be understood to be the anterior surface of the highest layer, i.e., the layer that is farthest from the surface of the eye when the lens is worn. The lens body may also be formed of a single lens layer. It will be understood that when the lens body is made of a single lens layer, the bulk material forming the lens body will be homogeneous, and therefore, there will be no discernible boundaries between the regions of bulk material forming the lens body.If the lens body is made of a single lens layer, the lens layer forms the entire lens body, in which case the terms lens layer and lens body can be used interchangeably. Presumably, the single lens layer forms the entire lens.

[0033] The orthokeratological contact lens may be substantially circular in shape in plan view and have a diameter ranging from 8 mm to 25 mm. Optionally, the lens diameter may range from 8 mm to 15 mm.

[0034] A corneal orthodontic contact lens according to the present disclosure has an anterior surface and an opposite posterior surface. The anterior surface faces away from the eye when the contact lens is placed on the eye, and the anterior surface may have a generally convex shape. The posterior surface faces toward the eye when the contact lens is placed on the eye. The posterior surface may have a generally concave shape. The posterior surface of the lens contacts the cornea of ​​the eye. As will be appreciated, at least a major portion of the posterior surface, e.g., at least 50%, at least 75%, or at least 90% of the posterior surface, may be in contact with the surface of the cornea when the lens is worn. Contact between the posterior surface of the lens and the cornea enables the lens to reshape the surface of the cornea as described herein.

[0035] The posterior surface of the orthocorneal lens has a correction zone. The correction zone is a region on the posterior surface of the lens that reduces the curvature of the central portion of the orthocorneal lens when the lens is worn. The lens is configured so that the correction zone overlies the pupil of the eye when the lens is worn. Preferably, the correction zone is located in the center of the lens about the central axis of the lens when the lens is viewed in a plan view. The correction zone is aligned with the central portion of the cornea to be treated. Preferably, the correction zone is substantially circular when viewed in a plan view.

[0036] The correction zone is constituted by a first section of the posterior surface having a radius of curvature greater than that of the central portion of the cornea. As will be appreciated, the greater the radius of curvature, the flatter the correction zone will be.

[0037] When the lens is worn, the correction region contacts the apex of the cornea, and the central region has a flatter or less steeply curved profile than the apex of the cornea, resulting in the central portion of the cornea being flattened by compression. Thus, the correction region is configured to correct distance vision in a myopic eye by flattening or reducing the curvature of the central portion of the treated cornea. Without being bound by theory, it is believed that the correction region reduces the curvature of the central portion of the cornea by displacing epithelial fluid and / or tissue from the central portion to the peripheral portion of the cornea. When the orthokeratology lens is worn, the central portion of the cornea is at least partially shaped to or influenced by the profile of at least a portion of the correction region of the lens. Thus, the topology of the central portion of the cornea is flatter after wearing the lens than before wearing the lens.

[0038] To correct the refractive error of myopia, the central portion of the cornea needs to be flattened, or made to have a smaller curvature. The minimum radius of curvature required for the correction zone of the lens should approach the radius of curvature required to correct low myopia, e.g., -0.25D myopia. High myopia requires a relatively high degree of flattening, and thus must have a correction zone with a larger radius of curvature than that required for low myopia. Thus, the maximum radius of curvature for the correction zone should approach the radius of curvature required to correct high myopia, e.g., -15D myopia.

[0039] The correction zone is defined by a first section of the posterior surface of the lens having a radius of curvature of 6 mm or more, e.g., a radius of curvature of 7 mm or more, or a radius of curvature of 8 mm or more. The correction zone may be defined by a first section of the posterior surface having a radius of curvature of less than 15 mm, less than 12 mm, less than 12 mm, or greater than 10 mm. The radius of curvature of the correction zone may be in the range of 6 mm to 15 mm, 6 mm to 12 mm, 6 mm to 10 mm, 6 mm to 9.5 mm, 7 mm to 9.5 mm, 7 mm to 9 mm, 6 mm to 8.5 mm, 8.8 mm to 9.3 mm, 6 mm to 6.8 mm, or 6 mm to 9.9 mm. Optionally, the radius of curvature of the correction zone may be in the range of 6 mm to 9.9 mm. When treating relatively low myopia, e.g., −1.0 D, it may be advantageous to provide a correction zone having a radius of curvature ranging from 7 mm to 9.5 mm. When treating relatively high myopia, e.g., −4.0 D or greater, it may be advantageous to provide a correction zone comprised of a portion of the posterior surface of the lens having a radius of curvature ranging from 6.8 mm to 15 mm.

[0040] Presumably, the correction zone provides additional correction beyond that required to treat myopia. This overcorrection allows for gradual reversion of the corneal profile to its untreated state during the day when the lens is no longer being worn. For example, an overcorrection of approximately -0.75D may be introduced by the correction zone to allow partial reversion of the central portion of the cornea to its natural, more curved state when the lens is not being worn. This overcorrection is called the Jessen factor. The overcorrection may be greater than -0.5D, greater than -1D, or greater than 2D. Presumably, the overcorrection may extend the period during which the cornea maintains focused distance vision when the lens is not being worn. Overcorrection also increases the amount of fluid and / or cells moving into the peripheral portion of the cornea, as the central portion of the cornea flattens (flattens). This can help control the amount of treatment defocus with the annular treatment recess, as there is a large amount of fluid and / or cells that must be redistributed within the cornea.

[0041] The correction zone may have a diameter greater than 1 mm, greater than 2 mm, or greater than 3 mm. The correction zone may have a diameter less than 8 mm, less than 6 mm, less than 5 mm, or less than 4 mm. The correction zone may have a diameter in the range of 1 mm to 8 mm, 2 mm to 6 mm, more preferably 2.5 mm to 5.5 mm, and most preferably 3 mm to 4 mm. In a preferred embodiment, the correction zone has a diameter of about 3 mm, for example, 3.36 mm.

[0042] The correction zone may be defined by a first section of the posterior surface of the lens that is spherical. Alternatively, the correction zone may be defined by a first section of the posterior surface of the lens that is aspheric. As will be understood, an aspheric profile is a profile in which the radius of curvature is not constant throughout the section of the posterior surface corresponding to the diameter of the correction zone. For example, the radius of curvature at the center of the correction zone may be larger than the radius of curvature at either or both ends of the correction zone. Alternatively, the radius of curvature at the center of the correction zone may be smaller than the radius of curvature at either or both ends of the correction zone. The radius of curvature may increase at the edges of the correction zone. Alternatively, the radius of curvature may decrease toward the edges of the correction zone. An aspheric correction zone may be advantageous in achieving a more consistent base power throughout the central portion of the cornea, since the degree of oblateness can decrease with radial distance from the apex of the cornea. Optionally, the correction zone may be defined by a first section of the posterior surface that is adapted to treat astigmatism. For example, the profile of the posterior surface of the correction region may be toric.

[0043] The posterior surface of the lens further has an annular therapeutic recess extending radially outward from the periphery of the correction region. The lens is configured so that the annular therapeutic recess, together with the correction region, is aligned with the pupil of the eye when the lens is in use. When the lens is viewed in plan, the central correction region is centered on the central axis of the lens, and the annular therapeutic recess surrounds the central correction region. When the lens is worn, the annular therapeutic recess is aligned with the peripheral portion of the cornea to be treated. Preferably, the annular therapeutic recess is substantially circular in plan.

[0044] The annular therapeutic recess introduces myopic defocus into the peripheral portion of the cornea, and is constituted by a second section of the posterior surface having a radius of curvature that is smaller than the radius of curvature of the first section of the posterior surface (i.e., the correction region). Because the radius of curvature of the annular therapeutic recess is smaller than the radius of curvature of the correction region, the annular therapeutic recess has a greater curvature, and the annular therapeutic recess provides an add power to the treated cornea. As will be appreciated, the shorter the radius of curvature of the second section of the posterior portion of the lens, the greater the curvature of the annular therapeutic recess and the greater the add power. The annular therapeutic recess is formed on the posterior surface of the lens, which is concave.

[0045] When the lens is in use, the annular therapeutic recess allows the peripheral portion of the cornea to increase in thickness and curvature. The increase in thickness / curvature results from increased pressure in the central region of the cornea (caused by the corrective region of the lens), which causes a redistribution of fluid and / or tissue to the peripheral portion. As can be appreciated, the surface of the cornea assumes a profile influenced by the profile of the posterior surface of the lens, as the surface of the cornea is compressed to at least partially match the shape of the posterior surface of the lens. Thus, the peripheral portion of the cornea aligned with the annular therapeutic recess is shaped by the annular therapeutic recess when the lens is worn, and this peripheral portion has an added (convex) curvature. The shaped peripheral portion of the cornea adds positive refractive power or myopic defocus to the cornea. The annular therapeutic recess controls the shape of the peripheral portion of the cornea, which provides myopic defocus in the treated eye. As will be appreciated, the shape of the peripheral portion of the cornea does not necessarily match the shape of the annular therapeutic depression, for example, the peripheral portion of the cornea may only partially fill the annular therapeutic depression when the lens is worn.

[0046] The correction region of the lens changes the central corneal curvature and also provides refractive power to the central portion of the cornea by flattening the region. The annular treatment depression provides undercorrection of distance vision or intentionally introduces myopic defocus into the cornea. The radius of curvature of a second section of the peripheral portion of the lens is greater than the refractive power resulting from the annular treatment depression flattening the central portion of the cornea, introducing at least +1D of myopic defocus into the peripheral portion of the treated cornea. As will be understood, diopters, or "D," are a unit of measurement for the refractive power of a lens and are a common term in the art. The add provided by the annular treatment depression to the peripheral portion of the cornea may be at least +1.5D, at least +2.0D, at least +4.0D, at least +6.0D, at least +8.0D, or at least +12.0D greater than the refractive power resulting from the flattening of the central portion of the cornea. The add provided by the annular therapeutic recess in the peripheral portion of the cornea can be less than +12.0D, less than +8.0D, or less than +6.0D. For example, the add provided by the annular therapeutic recess in the peripheral portion of the cornea can be at least +1.0D but less than 12.0D. This is achieved by controlling the curvature of the annular therapeutic recess. The annular therapeutic recess can also help create a uniform corrected area in the central portion of the cornea by accepting at least some of the fluid and / or tissue displaced from the central portion of the cornea. As disclosed herein, the width, depth, curvature, and location of the annular therapeutic recess can affect the amount of redistributed fluid and / or tissue accepted into the peripheral portion of the cornea.

[0047] The annular therapeutic recess introduces myopic defocus into the peripheral portion of the cornea by reducing the degree of flattening of the corneal curvature, leaving the cornea unflattened, or increasing the curvature of the peripheral portion of the cornea located under the annular therapeutic recess when the lens is worn. The radius of curvature of the annular therapeutic recess is selected according to the degree of flattening or increased curvature required in the peripheral portion of the cornea. The peripheral portion of the cornea is not fully corrected to provide distance vision. Thus, intentional undercorrection or myopic defocus is introduced into the peripheral portion of the cornea. Without being bound by theory, it is believed that myopic defocus introduced into the peripheral portion of the cornea contributes to slowing myopic progression. The dimensions of the annular therapeutic recess can be modified to control the amount of myopic defocus introduced and the location on the cornea where defocus is introduced.

[0048] In the annular therapeutic recess, the lens has a remaining portion of lens material in the direction of the lens thickness, the remaining portion having a recess and a surface that defines a closed end of the recess. The surface that defines the closed end of the recess is a second section of the posterior surface of the lens. The second section of the posterior surface of the lens has a curvature that defines the curvature of the recess.

[0049] The depth of a recess is defined as the distance from the open end of the recess (i.e., the rear surface that would exist if the recess were not there) to the closed end of the recess (i.e., the surface of the lens material that makes up the end of the recess). One or more recesses may have a depth of 3% to less than 100% of the thickness of the remaining portion of the lens material; for example, the recesses may have a depth of 10% to 80%, 20% to 60%, or 30% to 50% of the thickness of the remaining portion.

[0050] The radius of curvature of the second section of the posterior surface of the lens that defines the annular therapeutic recess may be in the range of 5.5 mm to 12 mm, e.g., 6.5 mm to 12.0 mm, 7.5 mm to 9.0 mm, 8.0 mm to 9.0 mm, 5.5 mm to 8.5 mm, 7.5 mm to 8.5 mm, or 8.5 mm to 9.5 mm. The curvature of the second section of the posterior surface that defines the annular therapeutic recess may be selected depending on the curvature of the correction zone. For example, if the radius of curvature of the first section of the posterior surface of the lens that defines the correction zone is in the range of 8.0 mm to 8.5 mm, the radius of curvature of the second section of the posterior surface that defines the annular therapeutic recess may be in the range of 7.7 mm to 8.2 mm. If the radius of curvature of the first section of the posterior surface of the lens, which constitutes the correction zone, is in the range of 8.8 mm to 9.3 mm, the radius of curvature of the second section of the posterior surface, which constitutes the annular treatment recess, should be in the range of 8.3 mm to 8.8 mm. Presumably, the flatter (less curved) the correction zone, the greater the amount of corneal fluid and / or tissue displaced by the lens, requiring a more curved annular treatment recess. Alternatively, at relatively high myopias, the correction zone may be flatter than at low myopias, but because the surface profile of the peripheral portion before corneal treatment is already highly curved, the annular treatment recess should have a radius of curvature equal to or less than the radius of curvature of the peripheral portion before corneal treatment, with the purpose of preserving or flattening the peripheral portion to obtain the desired myopic defocus. The radius of curvature of the second section of the posterior surface of the lens that constitutes the annular therapeutic recess is smaller than the radius of curvature of the first section of the posterior surface of the lens that constitutes the correction zone.

[0051] The annular therapeutic recess may have a width in the range of 0.5 mm to 5.5 mm, in the range of 1 mm to 4 mm, for example in the range of 1 mm to 2 mm. As will be appreciated, since the therapeutic recess is annular, the width may be defined as the distance between the perimeter of the inner edge of the recess and the perimeter of the outer edge of the recess (when viewing the lens in plan view) in the direction of movement from the center of the lens to the edge of the lens.

[0052] The annular therapeutic recess may be symmetric or asymmetric, i.e., the recess is defined by a second section of the posterior surface of the lens having either a symmetric or asymmetric profile. The annular therapeutic recess may be defined by a second section of the posterior surface of the lens that is spherical. Alternatively, the annular therapeutic recess may be defined by a second section of the posterior surface of the lens that is aspherical. The shape of the recess can provide a specific optical power to a portion of the cornea aligned with the recess of the lens. The annular therapeutic recess may be asymmetric such that a portion of the annular therapeutic recess located closest to the correction region has a smaller radius of curvature than a portion of the annular therapeutic recess located further from the correction region. As will be appreciated, such an asymmetric profile will cause the annular therapeutic recess to slope toward the correction region. Alternatively, the annular therapeutic recess may be asymmetric such that a portion of the annular therapeutic recess located closest to the correction region has a larger radius of curvature than a portion of the annular therapeutic recess located further from the correction region. As will be appreciated, such an asymmetric profile will cause the annular therapeutic recess to slope away from the correction region. The slope of the annular therapeutic recess can help direct tissue and / or fluid toward or away from a central portion of the cornea coincident with the correction region. The radius of curvature of the annular therapeutic recess can depend on the radius of curvature of the correction region.

[0053] The lens further includes an accommodation region radially outward from the periphery of the annular therapeutic recess. Thus, as will be understood, the accommodation region is also annular or generally annular in plan view, with the center of this treatment region located on the central axis of the lens. The accommodation region adjusts the myopic defocus introduced into the peripheral portion of the cornea by the annular therapeutic recess or central correction region. The accommodation region adjusts the degree of increase in corneal curvature in the peripheral portion resulting from increased pressure within the cornea caused by fluid and / or tissue redistribution toward the peripheral portion, and also controls the movement of fluid and / or tissue from the far periphery of the cornea to the peripheral portion of the cornea aligned with the annular therapeutic recess, as described herein. The accommodation region can additionally or alternatively help achieve a central corneal portion with uniform refractive power across the entire diameter of the cornea. For example, the accommodation region can act as an additional recess to accommodate the increase in corneal curvature in the peripheral portion resulting from increased pressure within the cornea caused by fluid and / or tissue redistribution toward the peripheral portion. The accommodative region may be located outside the optical zone so as not to interfere with the user's vision, and presumably the accommodative region does not overlap with the pupil of the eye when the lens is in use.

[0054] The accommodation zone has a radius of curvature defined by a third section of the posterior surface of the lens, the third section having a refractive power ranging from 12 diopters greater than the radius of curvature of the correction zone to 12 diopters less than the radius of curvature of the correction zone. For example, the third section of the posterior surface of the lens comprising the accommodation zone may have a curvature that provides a refractive power ranging from 0 diopters greater than the radius of curvature of the correction zone to 12 diopters greater than the radius of curvature of the correction zone, from 0 diopters greater than the radius of curvature of the correction zone to 8 diopters greater than the radius of curvature of the correction zone, or from 0 diopters greater than the radius of curvature of the correction zone to 4 diopters greater than the radius of curvature of the correction zone. Alternatively, a third section of the posterior surface of the lens, constituting the accommodation zone, can have a curvature that provides a refractive power ranging from 0 to 12 diopters less than the radius of curvature of the correction zone, from 0 to 8 diopters less than the radius of curvature of the correction zone, or from 0 to 4 diopters less than the radius of curvature of the correction zone.

[0055] The radius of curvature of the third section of the posterior surface of the lens constituting the accommodation zone may be in the range of 4.5 mm to 15 mm, for example, in the range of 4.5 mm to 12 mm, 7 mm to 15 mm, or 7 mm to 9 mm. The accommodation zone may have a width in the range of 0.5 mm to 5.5 mm, 1 mm to 4 mm, for example, in the range of 1 mm to 2 mm. Perhaps the radius of curvature of the third section is equal to the radius of curvature of the second section constituting the correction zone. Perhaps the radius of curvature of the third section is greater than the radius of curvature of the second section constituting the correction zone, for example, by at least 0.9 mm. Perhaps the radius of curvature of the third section is smaller than the radius of curvature of the second section constituting the correction zone, for example, by at least 0.9 mm. As will be appreciated, since the accommodation region is annular, this width can be defined as the distance between the perimeter of the inner edge of the accommodation region and the perimeter of the outer edge of said region in the direction of movement from the center of the lens to the edge of the lens (when looking at the lens in a plan view).

[0056] The accommodating zone may be asymmetric, i.e., the accommodating zone may be defined by a third section of the posterior surface of the lens having a symmetric profile. The accommodating zone may be asymmetric, i.e., the accommodating zone may be defined by a third section of the posterior surface of the lens having an asymmetric profile. The accommodating zone may be defined by a third section of the posterior surface of the lens that is spherical. Alternatively, the accommodating zone may be defined by a third section of the posterior surface of the lens that is aspherical. The shape of the accommodating zone can impart a particular optical power to the lens. The accommodating zone may be asymmetric such that a portion of the accommodating zone closest to the annular therapeutic recess has a smaller radius of curvature than a portion of the accommodating zone that is further from the annular therapeutic recess. As will be appreciated, such an asymmetric profile causes the accommodating zone to slope toward the annular therapeutic recess and the correction zone. Alternatively, the accommodating zone may be asymmetric such that a portion of the accommodating zone closest to the annular therapeutic recess has a larger radius of curvature than a portion of the accommodating zone that is further from the annular therapeutic recess. As will be appreciated, such an asymmetric profile causes the accommodation region to slope away from the annular therapeutic recess and the correction region, which can help direct tissue and / or fluids toward or away from the portion of the cornea that is aligned with the annular therapeutic recess, as needed. The radius of curvature of the accommodation region can depend on the radius of curvature of the correction region.

[0057] In some embodiments, the radius of curvature of the accommodation region is smaller than the radius of curvature of the correction region. In such embodiments, the accommodation region can serve to contain fluid and / or tissue displaced by the correction region, which is not accepted by the annular treatment recess of the lens. This can be particularly advantageous when the myopia being corrected is relatively high, e.g., -4.00D myopia. In such embodiments, a relatively large degree of flattening of the central portion of the cornea is required, and thus, a large amount of tissue and / or fluid is displaced by the correction region of the lens. The volume of displaced tissue and / or fluid may be greater than the volume required to produce the desired myopic defocus in the peripheral portion of the cornea. It is desirable to avoid excessive displaced tissue and / or fluid entering the peripheral portion of the cornea, as this would introduce additional refractive power beyond the desired refractive power in that region of the cornea. To help achieve a desired amount of myopic defocus in the peripheral portion of the cornea within a clearly defined area, the accommodation region may serve as a reservoir to receive excess displaced tissue and / or fluid. In this case, the accommodation region is a region of the lens where the curvature of the cornea can be expanded. Thus, the accommodation region in such embodiments can be considered a second recess, and this accommodation region can have any of the features disclosed in connection with the annular therapeutic recess. The accommodation region in such embodiments can introduce a second myopic defocus into the cornea.

[0058] Optionally, the orthokeratological lens has a correction zone defined by a first section of the posterior surface of the lens with a radius of curvature ranging from 6.8 mm to 15.0 mm, and a third section of the posterior surface defining the accommodation zone has a radius of curvature ranging from 4.5 mm to 15 mm, said radius of curvature being less than the radius of curvature of the first section of the posterior surface defining the correction zone. Optionally, a second section of the posterior surface of the lens defining the annular therapeutic recess has a radius of curvature ranging from 6.5 mm to 12.0 mm, provided said radius of curvature is less than the radius of curvature of the correction zone. Optionally, the third section of the posterior surface of the lens defining the accommodation zone has a radius of curvature less than the radius of curvature of the second section defining the annular therapeutic recess. For example, if the radius of curvature of a first section of the posterior surface of the lens defining the correction zone is in the range of 8.8 mm to 9.3 mm, the radius of curvature of a second section of the posterior surface defining the annular treatment recess may be in the range of 8.3 mm to 8.8 mm, and the radius of curvature of a third section of the posterior surface defining the accommodation zone may be in the range of 7.9 mm to 8.4 mm. Such lenses may be particularly effective in correcting and treating high myopia, e.g., myopia of at least -4.0 D.

[0059] In some embodiments, the radius of curvature of the accommodating region is greater than or equal to the radius of curvature of the correction region. In such embodiments, the accommodating region can act to direct fluid and / or tissue displaced by the correction region toward the portion of the cornea aligned with the annular treatment recess of the lens. This can be particularly advantageous when the myopia being corrected is relatively low, e.g., -1.0D myopia. In such embodiments, a relatively small amount of flattening of the central portion of the cornea is required, and thus, a small amount of tissue and / or fluid is displaced by the correction region of the lens. A large radius of curvature (flat profile) of the accommodating region can help direct tissue and / or fluid toward the region of the cornea aligned with the correction region, so that the annular treatment recess can introduce sufficient myopic defocus into the peripheral portion of the cornea. Presumably, if the accommodating region is relatively flat, it will not act as a reservoir against which the cornea can expand, thus preventing movement from the central and / or peripheral portions of the cornea toward the region aligned with the accommodating region.

[0060] Optionally, the orthokeratological lens has a correction zone defined by a first section of the posterior surface having a radius of curvature ranging from 7 mm to 9.5 mm and a second section of the posterior surface defining an annular therapeutic recess having a radius of curvature ranging from 5.5 mm to 8.5 mm, provided that the radius of curvature is smaller than the radius of curvature of the central correction zone. Optionally, the radius of curvature of the accommodation zone is in the range of 7.0 mm to 15 mm, and the radius of curvature of the third section is greater than the radius of curvature of the second section defining the annular therapeutic recess. Optionally, the radius of curvature of the accommodation zone is greater than or equal to the radius of curvature of the correction zone. For example, if the radius of curvature of the first section of the posterior surface of the lens defining the correction zone is in the range of 8.0 mm to 8.5 mm, the radius of curvature of the second section of the posterior surface defining the annular therapeutic recess may be in the range of 7.7 mm to 8.2 mm, and the third radius of curvature of the posterior surface defining the accommodation zone may be in the range of 8.0 mm to 8.5 mm. Such lenses may be particularly effective in correcting and treating low myopia, for example, about -1.0D.

[0061] The accommodating region may be positioned within the posterior surface of the lens such that it is tilted toward or away from the center of the correction region. As will be appreciated, the tilt may be created in the accommodating region by creating an asymmetric profile within a third section of the posterior surface of the lens. The accommodating region may be asymmetric such that a portion of the accommodating region located closest to the annular therapeutic recess has a smaller radius of curvature than a portion of the accommodating region located further from the annular therapeutic recess. As will be appreciated, such an asymmetric profile tilts the accommodating region toward the annular therapeutic recess and the correction region. Alternatively, the accommodating region may be asymmetric such that a portion of the accommodating region located closest to the annular therapeutic recess has a larger radius of curvature than a portion of the accommodating region located further from the annular therapeutic recess. As will be appreciated, such an asymmetric profile tilts the accommodating region away from the annular therapeutic recess and the correction region. The tilt direction of the accommodating region may be selected according to the desired direction of tissue and / or fluid flow within the cornea. For example, in a lens designed to treat low myopia (e.g., −1.0D myopia), the treatment region may be angled away from the annular treatment recess and the correction region. This may direct corneal fluid and / or tissue toward the portion of the cornea bounded by the annular treatment recess and the correction region and / or prevent fluid and / or tissue from moving toward the outer region of the cornea, which may be bounded by the fitting region. In such a configuration, perhaps more fluid and / or tissue is available to align with the annular treatment recess and / or the correction region, which may help achieve a desired corneal profile in these regions. In a lens designed to treat high myopia (e.g., −4.0D myopia), the accommodation region may be angled toward the annular treatment recess and the correction region. This can direct corneal fluid and / or tissue toward the outer region of the cornea, which may be bounded by the fitting region, and / or away from the portion of the cornea bounded by the annular treatment recess and correction region.When the adjustment region is angled toward the annular treatment recess and the correction region, corneal fluid and / or tissue directed from the central portion of the cornea is likely to be directed toward an outer region of the cornea that can be aligned with the fitting region. This configuration also likely prevents backflow of corneal tissue and / or fluid from the outer region of the cornea toward the central region. This lens configuration can direct excess corneal fluid and / or tissue away from the annular treatment recess, thereby controlling the desired myopic defocus in the peripheral portion of the lens.

[0062] Lenses according to the present disclosure may optionally include an accommodation region that abuts the annular therapeutic recess directly, i.e., the outer periphery of the annular therapeutic recess may define the boundary between the annular therapeutic recess and the accommodation region. Thus, the annular therapeutic recess may be located adjacent to the accommodation region. At the boundary between adjacent accommodation regions and annular therapeutic recesses, there may be an abrupt, discontinuous increase or decrease in radial curvature power, depending on the relative radial curvature add power of the annular therapeutic recess and the accommodation region, respectively.

[0063] Perhaps the radius of curvature of the accommodation region is equal to the radius of curvature of the annular therapeutic recess. In such embodiments, the accommodation region and the annular therapeutic recess may be spaced apart within the lens such that there is a clear demarcation between the end of one region and the beginning of another. For example, a portion of the posterior surface of the lens having a radius of curvature equal to the radius of curvature of the correction region may separate the annular therapeutic recess from the accommodation region.

[0064] Possibly, one or more additional regions are disposed between the annular therapeutic recess and the correction region. Such regions may be directed toward the peripheral portion of the cornea located under the annular therapeutic recess when the lens is worn. For example, such regions may have properties similar to the accommodative regions described herein, except that they are disposed opposite the therapeutic recess, i.e., they are aligned with the inner periphery of the annular therapeutic recess. Alternatively, such regions may be directed away from the portion of the cornea located under the annular therapeutic recess when the lens is worn. For example, such regions may have properties similar to those of the annular therapeutic recess.

[0065] Optionally, the posterior surface of the lens may further include a fitting region for stabilizing the lens against the cornea, the fitting region extending radially outward from the periphery of the accommodation region. Thus, lenses according to the present disclosure may include a fitting region for stabilizing the lens.

[0066] The fitting zone is a portion of the lens located outside the optical zone. Thus, the fitting zone is not aligned with the pupil of the eye when the lens is worn; instead, it is located outside the peripheral portion of the cornea. When viewed in plan, the fitting zone surrounds the accommodation zone, with its center located on the central axis of the lens. Preferably, the fitting zone is substantially circular when viewed in plan. The fitting zone has no optical properties, but is used to anchor the lens to the eye during use. This helps prevent the lens from moving or slipping on the eye during use. Optionally, the fitting zone has a radius of curvature approximately equal to the radius of curvature of the portion of the eye to be treated. The fitting zone may have multiple zones, each with a different radius of curvature. Each zone may have a radius of curvature ranging from 8 mm to 12 mm, preferably from 8.5 mm to 10.5 mm; for example, the radius of curvature may be approximately 9 mm. The fitting region is presumably rigid so that it does not flex or change shape under the pressure of fluid being redistributed within the cornea. In this way, the fitting region helps direct fluid / cells into the region of the cornea aligned with the annular region. Optionally, the fitting region may have a larger radius of curvature than the portion of the cornea that is aligned with the fitting region when the lens is worn. In this way, the fitting region can exert additional pressure on the eye (e.g., additional pressure is exerted by the fitting region on one side of the cornea). This may be beneficial in redistributing tissue and / or fluid toward the center of the cornea, and the fitting region may preferably be provided in lenses designed to treat relatively low degrees of myopia. Alternatively, the fitting region may have a smaller radius of curvature than the portion of the cornea that is aligned with the fitting region when the lens is worn. Such a fitting region has a higher curvature than the portion of the cornea with which the fitting region is aligned, and therefore, it can be said that the fitting region does not exert additional pressure on the cornea.This allows the eye to expand in an area aligned with the fitting zone (i.e., on one side of the cornea), which may preferably be provided in lenses designed to treat relatively high degrees of myopia. The fitting zone may have a width of at least 1 mm, at least 3 mm, or at least 4 mm. The fitting zone may have a width of 9 mm or less, 7 mm or less, or 5 mm or less. For example, the fitting zone may have a width ranging from 1 mm to 7 mm, e.g., 1.5 mm. As will be appreciated, since the fitting zone is annular, the width may be defined as the distance (when viewing the lens in plan view) between the perimeter of the inner edge of the fitting zone and the perimeter of the outer edge of the fitting zone in the direction of movement from the center of the lens to the edge of the lens.

[0067] Optionally, the lens has an edge lift, which can help the user lift the lens off the cornea.

[0068] A method of forming an orthokeratological lens according to the present disclosure may include any of the features of the above-mentioned aspects.

[0069] Corrective corneal lenses according to the present disclosure may optionally reshape the corneal profile to mimic the core properties of the MISIGHT contact lens, i.e., the lens may provide a corneal profile that includes a central correction zone (a flattened central portion of the cornea) having a diameter of 3.30-3.40 mm and +2.0 D add, and optionally a raised peripheral portion (a peripheral portion of the cornea with increased curvature or myopic defocus) having a diameter of 1.40-1.50 mm.

[0070] The lenses may be formed by casting, spin casting, or lathing, or a combination thereof. As will be understood by those skilled in the art, casting refers to forming a lens by placing a lens-forming material between a female mold member having a concave lens-forming surface and a male mold member having a convex lens-forming surface.

[0071] The manufacturing method may include forming a female mold member having a concave lens-forming surface and a male mold member having a convex lens-forming surface. The method may include filling a gap between the female and male mold members with bulk lens material. The method may further include curing the bulk lens material to form the lens. As will be appreciated, the posterior and anterior surfaces of the lens will conform to the concave and convex surfaces and the mold surfaces, and thus the profile of the lens surfaces is controlled by the profile of the mold surfaces.

[0072] The annular therapeutic recess and / or the accommodating region can be formed in the lens layer by lathing, etching, or laser machining a recess or region into the lens layer. A lens body having a posterior surface may first be formed, for example in a mold, without the annular therapeutic recess and / or the accommodating region. Presumably, the posterior surface of the lens body forms the posterior surface of the lens once the annular therapeutic recess and the accommodating region are formed. The lens body may have a substantially uniform radius of curvature throughout the posterior surface. Presumably, the radius of curvature throughout the posterior surface is equal to the radius of curvature of the corrective region. The method then includes removing a portion of the lens body using a lathe or etching or laser machining to form a second section of the posterior surface that constitutes the annular therapeutic recess and / or a third section of the posterior surface that constitutes the accommodating region. Thus, once the lens body is formed, a portion of the lens body may be removed using a lathe or etching or laser machining to form the desired lens having a posterior surface according to the present invention. This technique may be used to vary the curvature of one or many sections of the posterior surface of the lens body, thus creating an annular therapeutic recess or accommodation region on the posterior surface, with the resulting lens body having a posterior surface in accordance with the present disclosure.

[0073] Alternatively or additionally, at least one of the annular therapeutic recess and the accommodation zone can be formed in the lens layer using a mold. Optionally, the mold surface can form at least one of a first section of the posterior surface that constitutes the correction zone of the lens, a second section of the posterior surface that constitutes the annular therapeutic recess of the lens, and a third section of the posterior surface that constitutes the accommodation zone of the lens. Perhaps the mold forms the correction zone of the lens, and the annular therapeutic recess and the accommodation zone are formed by another process disclosed herein, such as a lacing process, an etching process, or a laser machining process. The mold may have one or more protrusions that form at least one of the correction zone, the annular therapeutic recess, or the accommodation zone. The shape and curvature of the protrusion determine the radius of curvature of the section of the posterior surface of the lens that constitutes the annular therapeutic recess or the accommodation zone.

[0074] At least one of the annular therapeutic recess and the accommodation zone can additionally or alternatively be formed by pressing an imprinting arm into the posterior surface of the lens while holding the lens in place. This can be done multiple times using imprinting arms with different diameters to form imprints of different sizes on the posterior surface of the lens. The shape and curvature of the imprinting arm will determine the radius of curvature of the section of the posterior surface of the lens that makes up the annular therapeutic recess and the accommodation zone.

[0075] Those skilled in the art will recognize that the order of steps described with respect to the method according to the first aspect, or any other aspect of this disclosure, is not limited to the order provided.

[0076] According to a third aspect of the present invention, there is provided a method of manufacturing an orthokeratological contact lens, comprising: the contact lens having a posterior surface with multiple segments each having a radius of curvature, a first segment defining a corrective zone of the contact lens, a second segment defining an annular therapeutic recess of the contact lens, and a third segment defining an accommodative zone of the contact lens; The method includes selecting a radius of curvature for each segment, the step of selecting the radius of curvature comprising: i) selecting a radius of curvature of the first section, wherein the radius of curvature of the first section is at least 6 mm; ii) selecting a radius of curvature for the second segment, the radius of curvature for the second segment being smaller than the radius of curvature for the first segment; iii) selecting a radius of curvature of the third segment, the radius of curvature of the third segment being in the range of 4.5 mm to 15 mm; iv) manufacturing the contact lens such that the posterior surface comprises multiple sections having the radii of curvature selected in steps i), ii), and iii), respectively.

[0077] As will be appreciated, any feature of the first or second aspect of the invention can be combined with the third aspect of the invention. For example, the method according to the third aspect can be used to manufacture a lens according to the first aspect. The correction region, annular therapeutic recess, and accommodation region of the third aspect of the invention can include any feature described in connection with the first or second aspect of the invention. Furthermore, the method according to the third aspect of the invention can include any feature of the second aspect of the invention. For example, the lens can be formed in a mold. Optionally, at least one of the annular therapeutic recess and accommodation region can be formed by lacing.

[0078] According to a fourth aspect of the present invention, there is provided a method for treating the progression of myopia, comprising providing a lens of the present invention to a patient in need thereof. As will be appreciated, the patient is myopic, and the method includes treating one or both of the myopic eyes of the myopic patient. The patient is preferably 25 years of age or younger. The patient may be 20 years of age or younger, or 15 years of age or younger. The patient may be 12 years of age or younger. The orthocorneal lenses of the present disclosure may be particularly advantageous for treating myopia in children 12 years of age or younger. Presumably, myopia in children 12 years of age or younger has not yet developed or is only mild, and therefore its progression or worsening is easier to slow or prevent. Presumably, the use of orthocorneal lenses of the present disclosure may be particularly effective in preventing the onset of myopia, or at least slowing the progression of myopia, in patients with a family history (i.e., a genetic predisposition) of myopia.

[0079] A method for treating the progression of myopia may include reshaping a patient's cornea by fitting a lens of the present invention to the patient's cornea. The method may correct myopia so that the patient has clear, long-distance vision when the lens is removed from the eye. The method may introduce myopic defocus into the peripheral portion of the cornea as described herein. For example, the method may introduce myopic defocus of at least +1D, at least +1.5D, at least +2D, at least +4D, at least +6D, or at least +8D into the cornea. The radii of curvature of the corrected area of ​​the cornea and the myopic defocus area of ​​the cornea are defined by the correction area and the treatment recess of the lens, respectively. For example, a correction area of ​​the lens having a diameter of approximately 3 mm may provide correction to a central portion of the cornea having a diameter of approximately 3 mm.

[0080] Once fitted to the patient's eye, the lens should be worn for a sufficient time to allow the shape of the cornea to conform, or at least substantially conform, to the shape of the lens. For example, the lens should be worn for at least 5 hours, or at least 8 hours. Preferably, the lens is worn overnight while the patient is sleeping, thereby allowing the cornea of ​​the eye to reshape while the patient is not seeking their vision. Once the cornea has reshaped so that it has a profile substantially identical to the posterior surface of the lens, the lens should be removed. The reshaped cornea profile lasts for several hours, e.g., at least 5 hours, at least 8 hours, or at least 12 hours. Thus, the patient's distance vision is improved compared to the eye's natural state (i.e., the patient's vision before the patient was treated with the lens). Once the lens is removed from the eye, compressive forces are no longer exerted on the cornea, and the cornea therefore returns to its natural state. Re-insertion of the lens allows the cornea to reshape again. Thus, the patient can wear the lenses every day while leaving them out during the day.

[0081] The present invention seeks to control the location and refractive power characteristics of myopic defocus introduced into the peripheral portion of the cornea by forced flattening of the central myopic portion. Additionally or alternatively, the present invention seeks to control the size and curvature of the corrected central portion of the cornea. This can be achieved by using an annular therapeutic depression and an accommodative region in the orthokeratology lenses described herein.

[0082] The orthokeratology contact lens 201 (FIG. 2A) of the present invention may be suitable for treating relatively high myopia (e.g., -4D myopia). The lens 201 is configured to be worn on the cornea of ​​an eye (not shown). The lens 201 has a posterior surface 202 and an anterior surface 204. A first section of the posterior surface 202 defines a central correction region 206. The first section of the posterior surface 202 defining the central correction region 206 has a radius of curvature smaller than that of the cornea. A second section of the posterior surface 202 defines an annular therapeutic recess 208. The annular therapeutic recess 208 is defined by the second section of the posterior surface having a radius of curvature smaller than that of the correction region 206. A third section of the posterior surface 202 defines an accommodation region 210. The accommodation region 210 comprises a third section of the posterior surface of the lens having a radius of curvature that is smaller than both the radius of curvature of the correction region 206 and the radius of curvature of the annular therapeutic recess 208. Located at the periphery of the lens is a fitting region 212. The fitting region 212 helps stabilize the lens 201 on the eye during use. The fitting region 212 may have a continuous radius of curvature across its width, or may have multiple radii of curvature across its width.

[0083] Lens 208 has four concentric regions (FIG. 2B). The center of each region is located on the axis of lens 201. The central portion of lens 201 is a correction region 206. An annular therapeutic recess 208 extends radially outward from the periphery of the corresponding region 206. Adjacent to the annular therapeutic recess 208 is an accommodation region 210. The outermost region of lens 208 is a fitting region 212.

[0084] The orthokeratology contact lens 301 (FIG. 3A) may be suitable for correcting and treating relatively low myopia (e.g., −1D myopia). The lens 301 is configured to be worn on the cornea of ​​an eye (not shown). The lens 301 has a posterior surface 302 and an anterior surface 304. A first section of the posterior surface 302 defines a central correction region 306. The first section of the posterior surface 302 defining the central correction region 306 has a radius of curvature that is smaller than the radius of curvature of the cornea (not shown) to be treated. Because the lens is intended to treat relatively low myopia, the correction region 306 may be more curved or less flattened than the correction region 206 shown in FIG. 2A. A second section of the posterior surface 302 defines an annular treatment recess 308. The annular treatment recess 308 is defined by a second section of the posterior surface having a radius of curvature that is smaller than the radius of curvature of the correction region 306. A third section of the posterior surface 302 constitutes an accommodative region 310. The accommodative region 310 is constituted by a third section of the posterior surface of the lens having a radius of curvature equal to the radius of curvature of the corrective region 306 and greater than the radius of curvature of the annular therapeutic recess 308. Thus, in contrast to the lens 201 shown in FIG. 2A, the lens 301 shown in FIG. 3A has a relatively flat accommodative region. Located at the periphery of the lens is a fitting region 312. The fitting region 312 helps stabilize the lens 301 on the eye during use. The fitting region 312 may have a continuous radius of curvature across its width, or may have multiple radii of curvature across its width.

[0085] Lens 308 has four concentric regions (FIG. 3B). The center of each region is located on the axis of lens 301. The central portion of lens 301 is correction region 306. An annular therapeutic recess 308 extends radially outward from the periphery of correction region 306. Adjacent to annular therapeutic recess 308 is accommodation region 310. The outermost region of lens 301 is fitting region 312.

[0086] In use, the orthokeratology contact lens 401 is placed over the cornea 414 (FIG. 4A) to be treated (only the uppermost surface of the cornea 414 is shown, and it will be understood that the uppermost surface of the cornea includes the epithelial layer 416). The correction region 406 is aligned with the central portion of the cornea 414, which includes the apex of the surface of the cornea 414. The annular treatment recess 408 is aligned with the peripheral portion of the surface of the cornea 414. For clarity, the accommodation region is not shown in FIG. 4A, but is located between the annular treatment recess 408 and the fitting region 412. FIG. 4A uses different shading to indicate different regions of the lens.

[0087] The structure of the corneal epithelial layer 416 of the cornea 414 means that the epithelial layer 416 of the cornea 414 is flexible and moldable. The structure and physiological characteristics of the corneal epithelium allow its thickness to be altered by the application of sustained pressure. Fluid and / or tissue in the corneal epithelial layer 416 (and other organic substances commonly found in the eye) can be redistributed from one area of ​​the cornea 414 to another area by applying pressure to the surface of the cornea 414. Because the radius of curvature of the correction region 406 of the lens 401 is smaller than the radius of curvature of the cornea 414 to be treated, the correction region 406 contacts at least a central portion of the cornea 414 and applies a pressure or compressive force to the apex of the cornea 414 (indicated by the central vertical arrow in FIG. 4A ). As a result, fluid and / or tissue in the corneal epithelial layer 416 are forced toward the peripheral portion of the cornea 414, as shown in FIG. 4A by the arrows radiating from the center of the cornea 414. The annular treatment recess 408 aligns with the peripheral portion of the cornea 414 and provides space to allow expansion of the cornea 414 as a result of cell / fluid redistribution from the central region to the peripheral portion of the cornea 414 .

[0088] The surface profile of the cornea 414 (dashed line) before treatment differs from the surface profile of the cornea 414 after treatment (bold line) ( FIG. 4B ). Thus, the redistribution of fluid and / or cells within the epithelial layer 416 of the cornea 414 can be used to increase or decrease the corneal curvature, and thus the optical power. The central portion of the cornea 414 aligned with the correction region 406 is flattened, or has a smaller curvature, in the treated cornea 414 compared to the cornea 414 before treatment. Because the central portion of the treated cornea 414 has a smaller curvature, light reflected from distant objects is centered on the retina rather than in front of it, thereby correcting vision. In contrast, the peripheral portion of the cornea 414 adjacent to the annular treatment depression 408 is a raised, or more curved, portion of the treated cornea 414 compared to before treatment. The greater curvature of the peripheral portion of the cornea 414 after treatment than the central portion provides positive refractive power above the base power in the central portion. This region of add power or myopic defocus in the peripheral portion of the lens is believed to slow or limit the progression of myopia.

[0089] The corrected shape of the cornea 414 is maintained even after the lens 401 is removed from the eye. Over time, the shape of the cornea 414 will relax toward its uncorrected or pre-treatment state. When the shape of the cornea 414 reverts toward its uncorrected state to the point where long distance vision is impaired, the lens 401 can be placed back onto the cornea 414, thereby once again reshaping the profile of the cornea 414.

[0090] According to the present invention, the dimensions, including diameter, width, curvature, and shape, of the lens's correction zone, annular treatment recess, and accommodation zone can be adjusted to affect the resulting surface profile in the cornea being treated. For example, the diameter of the lens's correction zone affects the diameter of the central cornea that is flattened. It may be desirable to provide a standard diameter of the central cornea that is flattened for every myopic eye treated with the lens of the present invention. This can be achieved by selecting a diameter of the lens's central zone that corrects the diameter of the central cornea that is the same for every myopic eye being treated. For example, the central cornea corrected by the lens's correction zone may be approximately 3 mm in diameter. The diameter of the correction zone is likely selected depending on the degree of myopia to be treated. For example, a lens for treating low myopia may have a correction zone with a smaller diameter than a correction zone for treating high myopia. However, the radius of curvature of the lens' correction zone will vary from lens to lens depending on the myopic eye being treated, since high myopia requires more flattening. Generally, the greater the amount of myopic refractive error to be corrected, the flatter the central region (i.e., the larger the radius of curvature of the correction region). The lens annular treatment recess always has a larger radius of curvature than the lens's central correction zone, which provides additional power to the cornea. The radius of curvature, width, and shape of the annular treatment recess can be adjusted for each lens depending on the radius of curvature of the correction region. Similarly, the function of the lens accommodation region also depends on the size of the correction region, and thus the size of this region will vary with the curvature of the correction region or the degree of myopia being corrected. As described herein, the accommodation region can be a recess for corneal volume accumulation during treatment, or alternatively, the accommodation region can be a relatively flattened and angled region for reducing or facilitating volume accumulation in the peripheral portion of the cornea aligned with the lens annular treatment recess. Presumably, the greater the difference in refractive power between the correction zone and the annular treatment recess, the more flattened the accommodation zone will be (ie, the larger the radius of curvature of the accommodation zone).For example, the difference in refractive power between the correction region and the annular treatment recess can be +1D, +1.5D, +2D, +2.5D, +3D, +3.5D, +4D, +4.5D, +5D, +5.5D, +6D, +6.5D, or +7D. As should be understood, the difference in refractive power refers to the difference in refractive power provided to the central portion of the cornea aligned with the correction region and the peripheral portion of the cornea aligned with the annular treatment recess. The accommodating region has a radius of curvature such that sufficient epithelial fluid and / or tissue is distributed to the peripheral portion of the cornea to create the desired myopic defocus. If the difference in refractive power between the correction region and the annular treatment recess of the lens is large, perhaps an insufficient amount of epithelial tissue and / or fluid is displaced by the correction region, thus directing an insufficient amount of tissue and / or fluid toward the peripheral portion of the cornea to create the desired myopic defocus. Additionally or alternatively, it may be desirable to direct substantially all of the displaced fluid and / or tissue toward the peripheral portion of the cornea aligned with the treatment recess, thereby avoiding movement of the displaced tissue and / or fluid toward the periphery of the cornea. Therefore, when the difference in refractive power between the lens's correction region and the annular treatment recess is large, a relatively flat accommodation region may be desirable to direct tissue and / or fluid toward the peripheral portion aligned with the annular treatment recess. In contrast, when the difference in refractive power between the lens's correction region and the annular treatment recess is small, sufficient fluid and / or tissue may be directed toward the peripheral portion of the cornea aligned with the annular treatment recess. In this case, it may be desirable for the accommodation region to be a recess that accommodates excess displaced fluid and / or tissue. Therefore, when the difference in refractive power between the lens's correction region and the annular treatment recess is small, a relatively curved accommodation region (i.e., a recess) may be desirable to direct tissue and / or fluid toward the peripheral portion of the cornea aligned with the annular treatment recess. It will be understood that when we refer to "adjusting," "varying," etc., the dimensions of a region of a lens, this does not refer to changing the dimensions of the lens once it is formed, but rather means that a lens can be designed by selecting from a range of dimensions and then fabricating a lens of the selected dimensions. The various dimensions that can be adjusted will now be described with reference to Figures 5-8.The arrows in the figures indicate fluid and / or tissue movement within the cornea according to the profiles of the correction zone, the annular therapeutic recess, and the accommodation zone. The following embodiments relate to lenses suitable for producing a +2D myopic defocus in the peripheral portion of the cornea. As will be appreciated, the lenses of the present invention may be designed to produce a myopic defocus of less than +2D or more than +2D in the peripheral portion of the lens. The dimensions of the correction zone, the annular therapeutic recess, and the accommodation zone will be selected depending on the desired myopic defocus to be produced in the peripheral portion of the lens, as described herein.

[0091] Several regions and profiles of the lens 401 can be modified or altered to produce a particular optical profile in the cornea (FIG. 5). While the left and right sides of the lens 401 in FIG. 5 show different profiles of the lens regions, it should be understood that this is merely illustrative of the various dimensions of the regions that can be altered. As will be appreciated, the lenses of the present invention can have regions that are uniform in size across any meridian of the lens. The central correction region 406 of the lens 401 can be made smaller or larger in diameter depending on the desired diameter of the central portion of the cornea 414 to be flattened. The curvature of the correction region 406 can also be altered depending on the amount of myopia to be corrected. For example, a flattened or less curvatured central correction region 406 may be effective in treating high myopia (e.g., -4.0D myopia), while a more curvatured central correction region 406 may be effective for treating low myopia (e.g., -1.0D myopia). The shape of the central correction region 406 can also be altered. For example, the central correction region 406 may be symmetric or asymmetric. The shape of the correction region 406 may be aspherical. An aspherical profile may be particularly advantageous in providing a more uniform profile across the central portion of the corrected cornea. Similarly, the shape, diameter, and width of the annular treatment recess 408 and the accommodation region (not shown in FIG. 5 ) may also be modified. Additionally, the dimensions of the fitting region 412 may be modified to control the redistribution of fluid and / or tissue in the corneal epithelial layer 416. For example, the curvature of the fitting region 416 may be steeper or flatter. As can be seen, in FIG. 5 , the left side of the lens 401 has a steep fitting region 412 that is steeper than the corneal surface profile 414. The steep fitting region 412 presses against one side of the cornea 414 to drive fluid toward the center of the cornea 414. The right side of the lens 401 shows a fitting region 412 that is less steep than the cornea 414. The less steep fitting region 412 can dilate one side of the cornea 414, thus redistributing fluid and tissue in the corneal epithelial layer 416 away from the center of the cornea 414 and toward one side of the cornea 414.Possibly, the fitting area 412 has multiple areas, each with a different radius of curvature, thus allowing for more precise control of the applied pressure depending on this area of ​​the lens.

[0092] The dimensions of the annular recess of the lens can be modified. Referring to FIG. 6, the left side of the lens 401 shows variations in the width of the annular treatment recess 408 (only the right side is labeled). The right side of the lens 401 shows variations in the tilt or asphericity of the annular treatment recess 408. The annular treatment recess 408 can be tilted toward the central correction region 406, or the annular treatment recess 408 can be tilted away from the central correction region 406. The tilt of the annular treatment recess 408 can be used to control the direction of tissue and / or fluid flow in the epithelial layer 416 of the cornea 414. For example, if the annular treatment recess 408 is tilted away from the central correction region 406, the tissue and / or fluid in the epithelial layer 416 can be prevented from moving toward the periphery of the cornea 414. This can be advantageous when treating low myopia. In contrast, sloping the annular treatment recess 408 toward the central correction region 406 can facilitate tissue and / or fluid movement in the epithelial layer 416 toward the periphery of the cornea 416, which can be advantageous when treating high myopia.

[0093] Additionally, the size of the annular therapeutic recess can also be adjusted ( FIG. 7 ). For clarity, the adjustment region of the lens 401 is not shown. The left side of the lens 401 shows variations in the curvature of the annular therapeutic recess 408 (labeled only on the right side). The curvature of the annular therapeutic recess 408 affects the myopic defocus that is induced in the cornea 414. The smaller the radius of curvature of the annular therapeutic recess 408 (the greater the curvature of the annular therapeutic recess 408), the greater the curvature of the cornea 414 caused by fluid and / or tissue redistribution in the epithelial layer 416 that can accommodate the annular treatment 408. The right side of the lens 401 shows variations in the position of the annular therapeutic recess 408. The position of the annular therapeutic recess 408 determines the location of the myopic defocus that is induced in the cornea 414.

[0094] The dimensions of the accommodating region 410 can also be adjusted. Referring to FIG. 8, the left side of the lens 401 shows varying curvature and width of the accommodating region 410 (labeled only on the right side). The curvature of the accommodating region 410 affects the curvature of the cornea 414 in the area aligned with the accommodating region 410. The right side of the lens 401 shows varying asphericity and tilt of the accommodating region 410. The arrows indicate fluid and / or tissue movement within the epithelial layer 416 of the cornea 414. If the accommodating region 410 is concave, fluid and / or tissue movement within the cornea 414 will be directed toward the accommodating region 410. If the accommodating region 410 is flat, fluid and / or tissue movement within the cornea 414 will be directed toward the annular treatment depression 408 (dashed arrow in FIG. 8). The tilt of the accommodating region 410 can also affect the direction of fluid and / or tissue movement within the epithelial layer 416 of the cornea 414.

[0095] A method 500 (FIG. 9) for manufacturing a lens of the present invention includes a first step 501 of forming a lens having a posterior surface. This step may include forming a lens body having a posterior surface. The posterior surface of the lens body is then modified in various steps to form the posterior surface of the lens of the present invention. The method includes a step 502 of forming a correction region defined by a first section of the posterior surface. The method includes a step 503 of forming an annular treatment recess defined by a second section of the posterior surface. The method includes a step 504 of forming an accommodation region defined by a third section of the posterior surface. Possibly, the steps of forming the correction region 502, forming the annular treatment recess 503, and forming the accommodation region 504 are performed simultaneously during the formation of the lens or lens body in step 501. For example, the lens may be formed in a mold, the mold shaped to form a posterior surface of the lens with multiple curvatures, a first section of the posterior surface having a curvature that defines the correction region, a second section of the posterior surface having a curvature that defines the annular therapeutic recess, and a third section of the surface having a curvature that defines the accommodation region. Alternatively, the steps of forming the correction region 502, the annular therapeutic recess 503, and the accommodation region 504 may be performed sequentially (and in any order). For example, the method may include step 501 of forming a lens or lens body without at least one of the annular therapeutic recess or the accommodation region being present. In this situation, the posterior surface of the lens or lens body may have a radius of curvature equal to the radius of curvature of the correction region over substantially all of the surface of the component regions. Next, the step of forming the annular therapeutic recess 503 or the step of forming the accommodation region 504 may be performed by lacing to modify a section or sections of the posterior surface of the lens or lens body so that these sections have a radius of curvature that defines at least one of the annular therapeutic recess and the accommodation region in accordance with the present invention.

[0096] A method 600 (FIG. 10) of manufacturing a lens of the present invention is shown, the lens having a posterior surface with multiple segments, each having a radius of curvature. A first segment of the posterior surface of the lens constitutes the corrective region of the lens, a second segment constitutes the annular therapeutic recess of the lens, and a third segment constitutes the accommodative region of the lens. The method includes step 601 of selecting a radius of curvature for the first segment of the posterior surface of the lens. The radius of curvature of the first segment is at least 6 mm. The method includes step 603 of selecting a radius of curvature for a second segment of the posterior surface of the lens. The radius of curvature of the second segment is smaller than the radius of curvature of the first segment. The method includes step 605 of selecting a radius of curvature for a third segment of the posterior surface of the lens. The radius of curvature of the third segment is in the range of 4.5 mm to 15 mm. The method 600 finally includes a step 607 of manufacturing a lens such that the posterior surface has multiple segments with the radii of curvature selected in steps 601 , 603 and 605 .

[0097] While the present invention has been described and illustrated with reference to specific embodiments, those skilled in the art will recognize that the present disclosure lends itself to many different modifications not specifically illustrated herein.

[0098] Example Exemplary orthocorneal lenses of the present invention will now be described. The following examples relate to lenses suitable for producing a +2D myopic defocus in the peripheral portion of the cornea. As will be appreciated, the lenses of the present invention may be designed to produce less than +2D or more than +2D of myopic defocus in the peripheral region of the lens. The dimensions of the correction zone, the annular treatment recess, and the accommodation zone are selected based on the desired myopic defocus to be produced in the peripheral region of the lens, as described herein.

[0099] Example 1 - Low Myopia Correction and Treatment In a first example, an orthokeratology lens suitable for correcting low myopia of -1.00D was designed.

[0100] Assuming a nominal corneal power of 42D (8.03 mm) and a refractive index of -1.00DS, the following parameters were calculated for each region of the lens of Example 1:

[0101] Area 1 (Area of ​​Correction): Required Base Optical Zone Radius (BOZR) for central correction area = 42 D (nominal corneal power) + (plus) -1.00 (myopia correction) + (plus) -0.75 (Jessen coefficient) = 40.25 D. This correlates to a radius of curvature of 8.39 mm. The central zone diameter is selected to be 3.36 mm.

[0102] Region 2 (Annular Treatment Recess): To provide an addition of +2.00D, Region 2 must have a curvature of 40.25D + 2D = 42.25D. This correlates to a radius of curvature of 7.99mm. The width of Region 2 was selected to be 1.4mm.

[0103] Region 3 (accommodation region): The radius of curvature of region 3 was selected to be 8.39 mm. The width of region 3 was selected to be 1 mm.

[0104] Region 4 (fitting region): 0.0 to 0.9 mm flatter than the BOZR in region 1, i.e., 9.29 mm. The width is 1.5 mm.

[0105] Area 5 (fitting area): 0.0 to 0.9 mm flatter than the BOZR in area 1, i.e., 9.29 mm. The width is 1.5 mm.

[0106] The diameter and curvature of regions 4 and 5 (fitting regions) can be varied with the value of decentration for the cornea. These zones are used to stabilize the lens on the cornea.

[0107] Region 6 (edge ​​lift) has a radius of 0.1 mm. The edge lift is the outermost part of the lens that does not contact the cornea when the lens is worn.

[0108] For low myopia correction, less fluid and / or tissue needs to be displaced from the central correction region of the cornea compared to high myopia correction because the cornea requires less flattening. In the lens of Example 1, Region 3 (accommodative region) has a larger radius of curvature than Region 2 (annular treatment recess). Without being bound by theory, it is believed that Region 3 can direct the displaced fluid and / or tissue into the region of the cornea bounded by Region 2. This can create a large positive curvature and a large add power in the region of the cornea bounded by Region 2. It is intended that the refractive power in the region of the cornea bounded by Region 2 has at least +2D more add power than the region of the cornea bounded by the correction region (Region 1).

[0109] Example 2 - High Myopia In a second example, an orthokeratology lens suitable for correcting high myopia of -4.00D was designed.

[0110] Assuming a nominal corneal power of 42D (8.03 mm) and a refractive index of -4.00DS, the following parameters were calculated for each region of the lens of Example 2:

[0111] Zone 1 (Correction Zone): Base Optical Zone Radius (BOZR) required for central correction zone = 42 D (nominal corneal power) + (plus) -4.00 (myopia correction) + (plus) -0.75 (Jessen coefficient) = 37.25 D. This correlates to a radius of curvature of 9.06 mm (i.e., larger than the radius of curvature of Zone 1 required for low myopia in Example 1). The diameter of the central correction zone is selected to be 3.36 mm.

[0112] Region 2 (Annular Treatment Recess): To provide an addition of +2.00D, Region 2 must have a curvature of 37.25D + 2D = 39.25D. This correlates to a radius of curvature of 8.6mm. The width of Region 2 was selected to be 1.4mm.

[0113] Region 3 (accommodation region): The radius of curvature of region 3 was selected to be 8.18 mm. The width of region 3 was selected to be 1 mm.

[0114] Region 4 (fitting region): 0.0 to 0.9 mm flatter than the BOZR in region 1, i.e., 9.96 mm. The width is 1.5 mm.

[0115] Area 5 (fitting area): 0.0 to 0.9 mm flatter than the BOZR in area 1, i.e., 9.96 mm. The width is 1.5 mm.

[0116] The diameter and curvature of regions 4 and 5 (fitting regions) can be varied with the value of decentration for the cornea. These zones are used to stabilize the lens on the cornea.

[0117] Region 6 (edge ​​lift) has a radius of 0.1 mm. The edge lift is the outermost part of the lens that does not contact the cornea when the lens is worn.

[0118] For high myopia correction, greater central flattening of the cornea must occur than for low myopia correction. This results in a greater amount of cells and / or tissue being displaced from the central correction region. Displacement of cells and / or fluid toward the peripheral portion of the cornea typically results in a myopia treatment zone greater than +2D because of the greater amount of tissue and / or fluid that must be accommodated by the reverse curve. However, to control the diameter of the myopia treatment zone and limit the power shift to within the desired +2D range, Region 3 (accommodation region) has a steeper curvature than Region 2 (annular treatment recess). Without being bound by theory, Region 3 is believed to act as a well or reservoir for the excess tissue and / or fluid displaced by the correction zone (Region 1) and unable to be accommodated by the annular treatment recess (Region 2).

[0119] In this example, the curvature of the annular treatment recess and the adjustment region were modified to achieve the desired add power in the peripheral portion of the cornea, but perhaps the diameter of the annular treatment recess and the adjustment region could also be additionally or alternatively modified to control the amount of fluid and / or tissue admitted to the peripheral portion of the cornea.

[0120] In the foregoing description, reference has been made to integers or elements having known, obvious, or foreseeable equivalents, and such equivalents are hereby incorporated by reference as if individually set forth. Reference should be made to the following claims, which define the true scope of the invention, which should be deemed to include any such equivalents. The reader will also understand that any integers or features of the present disclosure described as advantageous, convenient, or the like are optional and do not limit the scope of any independent claim. Furthermore, it should be understood that, while considered beneficial in some embodiments of the invention, such optional integers or features may not be desirable and, therefore, may not be recited in other embodiments.

Claims

1. 1. A corrective corneal contact lens that corrects and slows the progression of myopia by reshaping a portion of the cornea of ​​a near-sighted person, comprising: The contact lens has a posterior surface in contact with the portion of the cornea to be reshaped, the posterior surface comprising: a correction zone for reducing the curvature of the posterior surface of the cornea, the correction zone being defined by a first section of the posterior surface having a radius of curvature of 6 mm or greater; an annular therapeutic recess for creating a myopic defocus in a peripheral portion of the cornea, the annular therapeutic recess being defined by a second section of the posterior surface extending radially outward from a periphery of the correction area and having a radius of curvature smaller than the radius of curvature of the first section, the radius of curvature of the second section being configured such that the annular therapeutic recess creates a myopic defocus of at least +1D in the peripheral portion of the cornea; 1. An orthokeratogenic contact lens having an accommodation region that adjusts for the myopic defocus caused by the annular therapeutic recess, the accommodation region being defined by a third section of the posterior surface extending radially outward from a periphery of the annular therapeutic recess and having a radius of curvature ranging from 4.5 mm to 15 mm.

2. 2. The orthocorneal contact lens of claim 1, wherein the second section of the posterior surface of the contact lens has a radius of curvature such that the annular therapeutic recess produces a myopic defocus of at least +1D but less than +12D in the peripheral portion of the cornea.

3. 2. The orthokeratology contact lens of claim 1, wherein the correction zone has a diameter ranging from 1 mm to 8 mm, preferably from 2.5 mm to 5.5 mm.

4. 2. The orthokeratological contact lens of claim 1, wherein at least one of the annular therapeutic recess and the accommodation region has a width in the range of 0.5 mm to 5.5 mm, preferably in the range of 1 mm to 2 mm.

5. the radius of curvature of the first section of the posterior surface of the contact lens that constitutes the correction area is in the range of 6.8 mm to 15 mm; a radius of curvature of the second section of the posterior surface of the contact lens defining the annular therapeutic recess is in the range of 6.5 mm to 12.0 mm, provided that the radius of curvature of the second section is less than the radius of curvature of the first section of the posterior surface; the radius of curvature of the third section of the posterior surface of the contact lens constituting the accommodation zone is in the range of 6.5 mm to 12.0 mm, provided that the radius of curvature of the third section is less than the radius of curvature of the first section of the posterior surface; The orthokeratological contact lens of claim 1 , wherein optionally, the radius of curvature of the third section of the posterior surface is less than the radius of curvature of the second section of the posterior surface.

6. the radius of curvature of the first section of the posterior surface of the contact lens that constitutes the correction area is in the range of 7 mm to 9.5 mm; a radius of curvature of the second section of the posterior surface of the contact lens defining the annular therapeutic recess is in the range of 5.5 mm to 8.5 mm, provided that the radius of curvature of the second section is less than the radius of curvature of the first section of the posterior surface; a radius of curvature of the third section of the posterior surface of the contact lens constituting the accommodation zone is in the range of 7.0 mm to 15.0 mm, provided that the radius of curvature of the third section is smaller than the radius of curvature of the first section of the posterior surface, and the radius of curvature of the third section is greater than the radius of curvature of the second section constituting the annular therapeutic recess; The orthokeratology contact lens of claim 1 , optionally wherein the radius of curvature of the accommodation region is equal to or greater than the radius of curvature of the correction region.

7. 10. The contact lens of claim 1, wherein the correction zone is defined by a first section of the posterior surface of the contact lens that is aspheric.

8. 10. The contact lens of claim 1, wherein at least one of the second section of the posterior surface of the contact lens that defines the annular therapeutic recess or the third section of the posterior surface of the contact lens that defines the accommodation zone has an asymmetric profile.

9. 10. The contact lens of claim 1, wherein the posterior surface of the contact lens further comprises a fitting region for stabilizing the contact lens against the cornea, the fitting region extending radially outward from a periphery of the accommodation region.

10. 10. A method of manufacturing an orthokeratology contact lens according to claim 1, wherein the contact lens is for correcting and treating myopia by reshaping a portion of the cornea of ​​a myopic eye, the method comprising forming the posterior surface of the contact lens, the step of forming the posterior surface comprising: forming the first section of the posterior surface, the first section constituting the correction area of ​​the contact lens and having a radius of curvature of 6 mm or greater; forming a second section of the posterior surface extending radially outward from a periphery of the correction region, the second section constituting the annular therapeutic recess and also having a radius of curvature smaller than the radius of curvature of the first section, the radius of curvature of the second section being such that the annular therapeutic recess produces a myopic defocus of at least +1D in the peripheral portion of the cornea; forming the third section of the posterior surface extending radially outward from a periphery of the annular treatment recess, the third section constituting the adjustment region and also having a radius of curvature in the range of 4.5 mm to 15 mm.

11. 1. A method of manufacturing an orthokeratological contact lens, comprising: the contact lens has a posterior surface with multiple segments, each having a radius of curvature, a first segment defining a correction zone of the contact lens, a second segment defining an annular therapeutic recess of the contact lens, and a third segment defining an accommodation zone of the contact lens; The method includes selecting a radius of curvature for each section, the step of selecting the radius of curvature comprising: i) selecting a radius of curvature of the first section, wherein the radius of curvature of the first section is at least 6 mm; ii) selecting a radius of curvature of the second section, the radius of curvature of the second section being smaller than the radius of curvature of the first section; iii) selecting a radius of curvature of the third section, the radius of curvature of the third section being in the range of 4.5 mm to 15 mm; iv) manufacturing the contact lens such that the posterior surface comprises multiple sections each having a radius of curvature selected in step i), step ii), and step iii).

12. 12. The method of claim 11, wherein the contact lens is as defined in claim 1.

13. 11. The method of claim 10, wherein the method comprises first forming the contact lens without at least one of the annular therapeutic recess or the accommodation region, and then using a lathe to change the curvature of the portion of the posterior surface of the contact lens to form the second section of the posterior surface that constitutes the annular therapeutic recess or the third section of the posterior surface that constitutes the accommodation region.

14. 11. The method of claim 10, wherein the method includes forming the contact lens in a mold, wherein one surface of the mold defines at least one of a first section of the posterior surface that defines the correction region of the contact lens, a second section of the posterior surface that defines the annular treatment recess of the contact lens, and a third section of the posterior surface that defines an accommodation region of the contact lens.

15. 10. A method of treating the progression of myopia, comprising providing the lens of claim 1 to a patient in need thereof.

16. 16. The method of claim 15, wherein the method includes reshaping the patient's cornea by fitting the lens to the patient's cornea.

17. 16. The method of claim 15, wherein the patient is under the age of 25.

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