RING-SHAPED TOOL

Abstract

The invention relates to a ring-shaped device capable of suppressing the effects of frictional forces generated between the ring-shaped device and the conjunctiva of the eyelid during blinking and capable of exhibiting superior stability on the eye when worn, compared with previous ring-shaped devices. The achievable goal is a ring-shaped device constructed to be worn on the surface of the sclera, comprising: an open portion designed to expose the cornea; and a body with a thin and unthinned zone, wherein the thinned zone is formed such that the maximum thickness of the zone decreases gradually from the right end to the upper and lower ends and from the left end to the upper and lower ends; and so on.

Description

Ring Device

[0001] The present invention relates to an annular device for wear on the scleral surface.

[0002] As a method for the drug treatment of eye diseases, a method using a drug delivery contact lens (DDSCL) has been developed, in which a drug is held within the contact lens and the drug is released gradually into ocular tissues when worn. According to this method, the DDSCL can be coated on the corneal surface, and therefore, a therapeutically effective concentration of the drug can be delivered to anterior ocular tissues such as the cornea and aqueous humor, and to external ocular tissues such as the tear fluid and conjunctiva.

[0003] However, with the method using DDSCL, it is difficult to selectively deliver drugs from the lens to posterior segment tissues such as the retina, choroid, sclera, vitreous body, etc. Therefore, in order to efficiently deliver drugs to posterior segment tissues, the present inventors developed an annular (ring-shaped) device having a main body that covers the scleral surface and an opening in the center that exposes the cornea (see Patent Document 1).

[0004] The annular device described in Patent Document 1 is designed so that the thickness of the intermediate portion formed between the inner and outer edge portions located at both ends of the width of the main body is greatest compared to other portions in order to obtain excellent wearing comfort and stability on the eyeball when worn on the eye. However, the annular device described in Patent Document 1 leaves room for improvement in terms of improving stability on the eyeball.

[0005] Therefore, the present inventors developed an annular device that further includes at least one substantially circumferential groove on the posterior surface of the intermediate portion of the annular device described in Patent Document 1 (see Patent Document 2). The annular device described in Patent Document 2 has a groove on the posterior surface of the intermediate portion, which suppresses mobility on the scleral surface, thereby improving stability on the eyeball.

[0006] Meanwhile, slab-off processing is used for eyeglass lenses and contact lenses. Slab-off processing refers to a process of removing a portion of a lens from its periphery to its center. Contact lenses obtained by slab-off processing have thin slab-off regions in the vertical direction of the lens, allowing for stable positioning (see Patent Document 3).

[0007] Patent Document 1: WO2010 / 092735 Patent Document 2: WO2014 / 192853 Patent Document 3: JP2009-169104A

[0008] The annular device described in Patent Document 2 has improved stability on the eyeball compared to the annular device described in Patent Document 1. However, even the annular device described in Patent Document 2 may slip due to the frictional force generated between the palpebral conjunctiva and the device when blinking, and there is a need for further stabilization. If the annular device slips on the eyeball when worn, not only will the wearer feel a foreign body sensation, but there is also a risk of inducing eye disorders such as scratches on the corneal surface.

[0009] The contact lens described in Patent Document 3 has a slab-off region, which allows for stable positioning on the ocular surface. However, because a contact lens is attached to the corneal surface, the frictional force and its effect generated during blinking are different from those of an annular device attached to the scleral surface. Furthermore, Patent Document 3 does not specifically describe the configuration of the slab-off region.

[0010] Therefore, the object of the present invention is to provide an annular device that, compared to the annular device described in Patent Document 2, suppresses the effects of friction that occurs between the annular device and the palpebral conjunctiva when blinking, and has excellent stability on the eyeball when worn.

[0011] The inventors have thoroughly investigated the shape of an annular device that is less susceptible to blinking when worn. They have found that an annular device including a slab-off region, in which the maximum thickness of the portion that contacts the palpebral conjunctiva when worn gradually decreases from one side to the other, reduces the frictional force generated by rubbing between the palpebral conjunctiva and the annular device surface, thereby suppressing blink-induced slippage. Furthermore, surprisingly, by increasing the maximum thickness of the non-slab-off region other than the slab-off region in the main body of the annular device compared to the annular devices described in Patent Documents 1 and 2, and further establishing a predetermined relationship between the maximum thicknesses of the slab-off region and the non-slab-off region, it is possible to reduce the frictional force during blinking, effectively suppress slippage, and improve the ease of handling and comfort of wearing the annular device. Based on this finding, the inventors have successfully created an annular device that can solve the problems of the present invention. The present invention was completed based on these findings and successful examples.

[0012] That is, according to the present invention, there are provided annular devices of the following aspects: [1] An annular device for wear on a scleral surface, comprising an opening for exposing the cornea and a main body having slab-off regions and non-slab-off regions formed so that the maximum thickness gradually decreases from the lower end to the upper end. [2] The annular device according to item [1], wherein the slab-off regions are symmetrical with respect to a perpendicular line. [3] The annular device according to item [2], wherein the slab-off regions are formed so that the maximum thickness gradually decreases from the lower end to the upper end, starting from a position where the central angle is any one of 40° to 170°. [4] An annular device for wear on a scleral surface, comprising an opening for exposing the cornea and a main body having slab-off regions and non-slab-off regions formed so that the maximum thickness gradually decreases from the right end to the upper and lower end, and from the left end to the upper and lower end. [5] The annular device according to item [4], wherein the slab-off region is symmetrical with respect to a perpendicular line. [6] The annular device according to item [5], wherein the slab-off region is formed so that its maximum thickness gradually decreases from the right end toward the upper end starting from a position where the central angle is any angle between 40° and 85°, and from the right end toward the lower end starting from a position where the central angle is any angle between 95° and 140°. [7] The annular device according to any one of items [1] to [6], wherein the surface area of ​​the slab-off region is 25% to 70% of the total surface area of ​​the main body. [8] The annular device according to any one of items [1] to [7], wherein the maximum thickness of the non-slab-off region of the main body is 120% to 450% of the minimum maximum thickness of the slab-off region. [9] The annular device according to any one of items [1] to [8], wherein the main body has at least one substantially circumferential groove on its rear surface.

[0013] The annular device of one embodiment of the present invention includes a slab-off region in a specific region of the device located on the upper eyelid side or on both the upper and lower eyelid sides. This reduces the effects of friction between the device and the palpebral conjunctiva during blinking, providing excellent stability on the eyeball when worn, thereby preventing slippage of the annular device and, as a result, reducing the occurrence of foreign body sensation and eye disorders when worn. Furthermore, the annular device of one embodiment of the present invention increases the maximum thickness of the non-slab-off region in the main body and establishes a predetermined relationship between the maximum thicknesses of the slab-off region and the non-slab-off region, thereby reducing friction during blinking, effectively preventing slippage, and improving the ease of handling and comfort of wearing the annular device. Furthermore, the annular device of one embodiment of the present invention, when used as a drug-releasing annular device, is capable of delivering a drug to a desired site on the eyeball.

[0014] FIG. 1A is a plan view and a cross-sectional view of one embodiment of the annular device of the first embodiment. FIG. 1B is a plan view and a cross-sectional view showing cross sections at each central angle of one embodiment of the annular device of the first embodiment. FIG. 2A is a plan view and a cross-sectional view of one embodiment of the annular device of the second embodiment. FIG. 2B is a plan view and a cross-sectional view of one embodiment of the annular device of the second embodiment having a groove on the posterior surface. FIG. 3 is a photograph of the annular device of Example 13 described below. FIG. 4 is a photograph of the area around the eye when wearing the annular device of Example 1 described below from the front. FIG. 5 is a photograph of the cross-sections of the annular device of Example 13 cut along a vertical line and a horizontal line, respectively, photographed with an optical coherence tomography (OCT).

[0015] Each aspect of the present invention will be described in detail below, but the present invention is not limited to the details of these items and can take various forms as long as the object of the present invention is achieved.

[0016] Unless otherwise specified, the terms used in this specification are used in the sense commonly used by those skilled in the art of ophthalmic lenses such as contact lenses and annular devices, and should not be construed as having an unduly limiting meaning. Furthermore, the speculations and theories made in this specification are based on the inventors' knowledge and experience to date, and therefore the present invention is not limited solely to such speculations and theories.

[0017] The term "and / or" means any one or any or all combinations of two or more of the associated listed items.

[0018] [Aspects of Annular Device] According to one aspect of the present invention, there is provided an annular device that is worn on the surface of the sclera and includes an opening that exposes the cornea and a main body that includes a slab-off region and a non-slab-off region other than the slab-off region. Depending on the position of the slab-off region, the annular device can be broadly classified into a first type and a second type.

[0019] In this specification, when the annular device is worn, the direction toward the upper eyelid is referred to as the upper end side, and the direction toward the lower eyelid is referred to as the lower end side. Furthermore, in the drawings described below, the upper direction of the annular device is referred to as the upper end side, the right direction as the right end side, the lower direction as the lower end side, and the left direction as the left end side. Furthermore, the surface visible in the drawings is the front surface of the annular device, and the surface visible from the back of the drawings is the rear surface of the annular device. The annular device is attached to the scleral surface from the rear side. When worn, the rear surface of the annular device adheres to the scleral surface of the ocular tissue, i.e., the surface of the bulbar conjunctiva covering the sclera.

[0020] The uppermost portion of the annular device is called the upper end, the rightmost portion on the right end is called the right end, the lowermost portion on the lower end is called the lower end, and the leftmost portion on the left end is called the left end. The point located at the center of the annular device, i.e., the center of the opening, is called the center point. The angle measured clockwise from the upper end position around the center point is called the central angle. The central angle at the upper end position is 0°, the central angle at the right end position is 90°, the central angle at the lower end position is 180°, and the central angle at the left end position is 270°.

[0021] The lines passing through the top and bottom ends of the annular device are vertical lines, and the lines passing through the right and left ends of the annular device are horizontal lines. The vertical and horizontal lines intersect at the center point.

[0022] The annular device of the first embodiment is characterized by a configuration including a slab-off region located on the upper eyelid side when worn. The slab-off region located on the upper end side reduces the frictional force generated by rubbing between the palpebral conjunctiva on the upper eyelid side and the front surface of the annular device when worn, making it possible to suppress misalignment during blinking. Figures 1A and 1B show plan views of one embodiment of the annular device of the first embodiment.

[0023] The second type of annular device is characterized by a configuration including a first slab-off region located on the upper eyelid side when worn and a second slab-off region located on the lower eyelid side. The two slab-off regions located on the upper and lower eyelid sides when worn firmly suppress rotational movement of the annular device, further improving suppression of blinking misalignment. Planar views of one embodiment of the second type of annular device are shown in Figures 2A and 2B.

[0024] Hereinafter, details of each aspect of the present invention will be described with reference to the drawings, but the present invention is not limited to what is shown in the drawings as long as the object of the present invention is achieved.

[0025] Photographs of the annular device of Example 13, which will be described later, are shown in Figure 3. As shown in the front view and perspective view, even though they are classified as the same ophthalmic lens, the shape of the annular device for wearing on the scleral surface is structurally completely different from that of a typical contact lens for wearing on the cornea. That is, the annular device has a circular (donut-like) shape with an opening for exposing the cornea, and has a large outer diameter.

[0026] Figure 4 shows a photograph of the area around the eye taken from the front when the annular device of Example 1, described below, is worn. As shown in Figure 4, the annular device is attached to the surface of the sclera, exposing the cornea. Furthermore, as shown schematically by the two circular lines in the reference photograph of Figure 4, the upper and lower ends of the annular device are always contained within the upper and lower eyelids, and frictional forces are generated between the upper and lower ends of the annular device and the palpebral conjunctiva when blinking. Because of this structure, the annular device is prone to slippage on the eyeball, making it difficult to hold it stably.

[0027] Therefore, the annular device of one embodiment of the present invention has a thinned slab-off region on the upper end side, or on both the upper and lower end sides, which reduces the frictional force generated between the annular device and the palpebral conjunctiva when blinking, suppresses slippage on the eyeball, and exhibits excellent stability.

[0028] The annular device of Example 13 was cut along a vertical line and a horizontal line, and the cross sections were photographed with an optical coherence tomography (OCT) as shown in Figure 5. As shown in Figure 5, the maximum thickness H'max of the slab-off region is smaller than the maximum thickness Hmax of the non-slab-off region. By providing such a slab-off region, the annular device of one embodiment of the present invention can exhibit excellent stability on the eyeball.

[0029] The basic configuration of the annular device may be any size that allows for comfortable wear and is large enough to cover the scleral surface. The size of the annular device may be set as appropriate. For example, the outer diameter is preferably 16 mm to 22 mm, more preferably 18 mm to 20 mm, taking into consideration ease of insertion into the eyeball, ease of wear, and coverage of the scleral surface. On the other hand, the inner diameter of the annular device (diameter of the opening) is preferably 10 mm to 15 mm, taking into consideration prevention of contact between the inner edge of the annular device and the cornea.

[0030] The base curve (BC) of the annular device may be set as appropriate as long as it adheres to the scleral surface, but from the viewpoint of adhesion to the scleral surface, it is preferably 9.5 mm to 18.0 mm, and more preferably 10.0 mm to 16.0 mm. Note that the base curve of a typical contact lens is 8.0 mm to 9.0 mm.

[0031] The annular device may have at least one substantially circumferential groove on its posterior surface, which contacts the scleral surface. When the annular device having a substantially circumferential groove on its posterior surface is worn, negative pressure is generated in the substantially circumferential groove, which suppresses movement of the annular device on the scleral surface and improves the stability of the annular device on the eyeball. The substantially circumferential groove refers to a groove provided along the circumferential direction (circumferential direction) of the annular device, and the shape of the groove is not particularly limited. That is, the substantially circumferential groove may be a circular groove provided along the entire circumferential direction, or may be a groove provided partially or intermittently in the circumferential direction, or a groove provided in a wavy pattern in the circumferential direction. Examples of the shape of the substantially circumferential groove include a semicircular cross-section; a polygonal cross-section such as a triangular or rectangular cross-section, and the semicircular cross-section is preferred. The number of substantially circumferential grooves may be set as appropriate, and is preferably one or more. Because a larger number of grooves may result in problems with the strength of the annular device, one to five grooves are more preferred, and one to three grooves are even more preferred.

[0032] The first embodiment of the annular device will be described below with reference to FIGS. 1A and 1B, and the second embodiment of the annular device will be described with reference to FIGS. 2A and 2B. These figures have a color gradation, with the darker areas representing the slab-off region, and the darker the color, the smaller the maximum thickness. For example, in FIG. 1A, the color becomes darker from the outer tangent point A1 to the outer tangent point X1, indicating that the maximum thickness gradually decreases from the outer tangent point A1 to the outer tangent point X1. In other words, in the slab-off region, the maximum thickness is not uniform from the outer tangent point A1 to the outer tangent point X1, but rather has a gradient from large to small.

[0033] 1A and 1B show a plan view and a cross-sectional view of one embodiment of the annular device (annular device 1) of the first embodiment. In Fig. 1A, the main body of the annular device 1 comprises a slab-off region 21 extending clockwise from a line segment A1-A'1 connecting an outer tangent point A1 on the outer peripheral edge to an inner tangent point A'1 on the inner peripheral edge between the outer tangent point A1 and the center point O1 to a line segment B1-B'1 connecting an outer tangent point B1 on the outer peripheral edge to an inner tangent point B'1 on the inner peripheral edge between the outer tangent point B1 and the center point O1. The annular device 1 has an asymmetric structure when the horizontal line HL1 is taken as the axis of symmetry.

[0034] The slab-off region 21 is formed so that the maximum thickness is smallest on the line segment X1-X'1 connecting the outer tangent point X1 on the outer peripheral edge at the upper end to the inner tangent point X'1 on the inner peripheral edge between the outer tangent point X1 and the center point O1. The maximum thickness refers to the thickness of the thickest part on the line segment connecting any outer tangent point on the outer peripheral edge to the inner tangent point on the inner peripheral edge between the outer tangent point and the center point.

[0035] The maximum thickness of the slab-off region 21 is formed to be smaller than the maximum thickness of the non-slab-off region 31. Specifically, the maximum thickness of the slab-off region 21 is configured to be smaller than the maximum thickness of the line segment Y1-Y'1 connecting the outer tangent point Y1 on the outer peripheral edge at the lower end and the inner tangent point Y'1 on the inner peripheral edge between the outer tangent point Y1 and the center point O1.

[0036] The maximum thickness of the non-slab-off regions 31 is substantially the same. Even if there is some difference in the maximum thickness of the non-slab-off regions 31, the maximum thickness at any part of the non-slab-off regions 31 is greater than any maximum thickness of the slab-off regions 21. For example, the maximum thickness of the non-slab-off regions 31 may be greatest at line segment Y1-Y'1 and may decrease slightly from line segment Y1-Y'1 to line segment A1-A'1 and line segment B1-B'1, but the total thickness is greater than any maximum thickness of the slab-off regions 21.

[0037] As shown in FIG. 1A, the annular device 1 has a gradient such that it gradually decreases clockwise from line segment A1-A'1 to line segment X1-X'1, and gradually decreases counterclockwise from line segment B1-B'1 to line segment X1-X'1, with the maximum thickness being smallest at line segment X1-X'1.

[0038] The maximum thickness of the slab-off region 21 and the maximum thickness of the non-slab-off region 31 may be set as appropriate, as long as the relationship that the maximum thickness of the slab-off region 21 is smaller than the maximum thickness at any point of the non-slab-off region 31 is maintained. For example, in order to reduce the frictional force generated by rubbing between the back side of the upper eyelid and the surface of the annular device when the annular device is worn, the maximum thickness of the slab-off region 21 is preferably 50 μm to 500 μm, more preferably 80 μm to 400 μm, and even more preferably 100 μm to 200 μm. From the viewpoint of compensating for the decrease in shape retention caused by providing a slab-off region in the annular device, the maximum thickness of the non-slab-off region 31 is preferably 150 μm to 700 μm, more preferably 200 μm to 600 μm, and even more preferably 200 μm to 500 μm.

[0039] In order to more effectively suppress shifting and rotational movement due to blinking when the annular device is worn, the ratio of the maximum thickness of the non-slab-off region 31 to the maximum thickness of the line segment X1-X'1 in the slab-off region 21 is preferably 100% to 500%, more preferably 120% to 450%, and even more preferably 150% to 400%.

[0040] The slab-off region 21 preferably has a line-symmetrical configuration with the perpendicular line VL1 as the axis of symmetry. In this case, the outer tangent point A1 and the outer tangent point B1 are in a line-symmetrical positional relationship with the perpendicular line VL1 as the axis of symmetry, and the inner tangent point A'1 and the inner tangent point B'1 are in a line-symmetrical positional relationship with the perpendicular line VL1 as the axis of symmetry. The following describes the case where the slab-off region 21 has a line-symmetrical configuration with the perpendicular line VL1 as the axis of symmetry.

[0041] If the line segment X1-O1 connecting the outer tangent point X1 and the center point O1 is taken as the starting line, and the line segment B1-O1 connecting the outer tangent point B1 and the center point O1 is taken as the moving radius, the angle from the starting line to the moving radius in the clockwise direction is called the central angle P1. The central angle P1, which is the starting point of the slab-off region 21 in the main body of the annular device 1, may be 40° to 170°, but in order to reduce the frictional force generated between the surface of the annular device and the back side of the upper eyelid during blinking, for example, it is preferably 60° to 160°, and more preferably 75° to 155°. Similarly, if the line segment X1-O1 is the starting line and the line segment A1-O1 connecting the outer tangent point A1 and the center point O1 is the radius azimuth, the angle from the starting line to the radius azimuth in the counterclockwise direction, which is the starting point of the slab-off region 21 in the main body of the annular device 1, may be between 40° and 170°, but is preferably between 60° and 160°, and more preferably between 75° and 155°.

[0042] As a specific example of the main body portion of the annular device 1, FIG. 1B shows cross-sectional views of the main body portion of the annular device 1 having a slab-off region starting at a central angle of 135°. As shown in FIG. 1B, the maximum thickness gradually increases from the line segment X1-X'1, which has a central angle of 0° (and 360°), to the line segment B1-B'1, which has a central angle of 135° and is the starting point of the slab-off region 21. Furthermore, the region from central angles 135° to 225° is a non-slab-off region, with a substantially uniform maximum thickness. Furthermore, the region from central angles 225° to 360° is a slab-off region, with the maximum thickness gradually decreasing.

[0043] As long as the annular device 1 employs the above-described configuration, other configurations can be set as appropriate. On the other hand, from the viewpoint of ease of handling, i.e., reducing the frictional force generated between the annular device and the palpebral conjunctiva when blinking and suppressing the effects of this friction to suppress slippage and rotational movement of the annular device while the annular device is worn and maintaining a certain shape, it is preferable that the surface area ratio of the slab-off region 21 to the non-slab-off region 31 of the annular device 1 be in a fixed relationship. For example, the surface area of ​​the slab-off region 21 is preferably 20% to 90%, more preferably 25% to 70%, and even more preferably 30% to 60% of the total surface area of ​​the main body of the annular device 1 (the total surface area of ​​the slab-off region 21 and the non-slab-off region 31).

[0044] Preferably, the annular device 1 has a shape in which the non-slab-off region 31 and / or the slab-off region 21 has a maximum thickness midway between the inner and outer edges.

[0045] For example, the non-slab-off region 31 preferably has a continuous configuration of an inner edge portion 311, an intermediate portion 312, and an outer edge portion 313, and any part of the intermediate portion has the maximum thickness, and more preferably is formed so that the thickness gradually decreases from the part having the maximum thickness in the intermediate portion toward the outer edge.

[0046] Similarly, for example, the slab-off region 21 preferably has a continuous inner edge portion 211, an intermediate portion 212, and an outer edge portion 213, and preferably has the maximum thickness in any part of the intermediate portion, and more preferably is formed so that the thickness gradually decreases from the portion of the intermediate portion having the maximum thickness toward the outer edge. However, depending on the maximum thickness in the intermediate portion 212, the thicknesses of the inner edge portion 211 and the outer edge portion 213 may become too small, which may reduce the shape retention and handleability of the annular device. Therefore, the inner edge portion 211, the intermediate portion 212, and the outer edge portion 213 may have a uniform thickness.

[0047] The widths of the portions corresponding to the inner and outer edge portions of the annular device 1 may be set as appropriate, and for example, the inner edge portions 211 and 311 each preferably have a width of 0.3 to 0.5 mm in the radial direction from the inner contact point on the inner peripheral edge of the opening side of the annular device 1 to the outer peripheral edge side. The outer edge portions 213 and 313 each preferably have a width of 0.3 to 0.5 mm in the radial direction from the outer contact point on the outer peripheral edge of the annular device 1 to the inner peripheral edge side. The intermediate portions 212 and 312 are the remaining portions of the annular device 1 excluding the inner and outer edge portions.

[0048] 2A and 2B show a plan view and a cross-sectional view of one embodiment of the second embodiment of the annular device (annular device 2). In Fig. 2A, the main body of the annular device 2 is composed of a slab-off region 22 extending clockwise from a line segment A2-A'2 connecting an outer contact point A2 on the outer peripheral edge with an inner contact point A'2 on the inner peripheral edge between the outer contact point A2 and the center point O2 to a line segment B2-B'2 connecting an outer contact point B2 on the outer peripheral edge with an inner contact point B'2 on the inner peripheral edge between the outer contact point B2 and the center point O2; a slab-off region 23 that is symmetrical to the slab-off region 22 with respect to a horizontal line HL2 as the axis of symmetry; and non-slab-off regions 32 and 33, which are portions excluding the slab-off regions 22 and 23.

[0049] The slab-off region 22 is formed so that the maximum thickness is smallest at the line segment X2-X'2 connecting the outer tangent point X2 and the inner tangent point X'2.

[0050] The maximum thickness of the slab-off region 22 is formed to be smaller than the maximum thickness of the non-slab-off region 32. Specifically, the maximum thickness of the slab-off region 22 is configured to be smaller than the maximum thickness at the line segment Y2-Y'2 connecting the outer tangent point Y2 and the inner tangent point Y'2, and the maximum thickness at the line segment Y3-Y'3 connecting the outer tangent point Y3 and the inner tangent point Y'3.

[0051] The maximum thickness of the non-slab-off regions 32 is substantially the same. Even if there is some difference in the maximum thickness of the non-slab-off regions 32, the maximum thickness at any point in the non-slab-off regions 32 is greater than any maximum thickness of the slab-off regions 22. For example, the maximum thickness of the non-slab-off regions 32 may be greatest at line segment Y2-Y'2 and decrease slightly from line segment Y2-Y'2 to line segment A2-A'2 and line segment A3-A'3, but the total thickness is greater than any maximum thickness of the slab-off regions 22.

[0052] As shown in FIG. 2A, the annular device 2 has a slope from line segment A2-A'2 in a clockwise direction to line segment X2-X'2 and from line segment B2-B'2 in a counterclockwise direction to line segment X2-X'2 such that the maximum thickness is smallest at line segment X2-X'2.

[0053] The maximum thickness of the slab-off region 22 and the maximum thickness of the non-slab-off region 32 may be set appropriately as long as the maximum thickness of the slab-off region 22 is smaller than the maximum thickness at any point of the non-slab-off region 32. For example, in order to reduce the frictional force generated by rubbing between the back side of the upper eyelid and the surface of the annular device when the annular device is worn, the maximum thickness of the slab-off region 22 is preferably 50 μm to 500 μm, more preferably 80 μm to 400 μm, and even more preferably 100 μm to 400 μm. From the viewpoint of compensating for the reduction in shape retention caused by providing a slab-off region in the annular device, the maximum thickness of the non-slab-off region 32 is preferably 150 μm to 700 μm, more preferably 200 μm to 600 μm, even more preferably 300 μm to 600 μm, and even more preferably 350 μm to 550 μm.

[0054] In order to more effectively suppress shifting and rotational movement due to blinking when the annular device is worn, the ratio of the maximum thickness of the non-slab-off region 32 to the maximum thickness of the line segment X2-X'2 in the slab-off region 22 is preferably 100% to 500%, more preferably 120% to 450%, and even more preferably 120% to 300%.

[0055] The slab-off region 22 preferably has a line-symmetrical configuration with the perpendicular line VL2 as the axis of symmetry. In this case, the outer tangent point A2 and the outer tangent point B2 are in a line-symmetrical positional relationship with the perpendicular line VL2 as the axis of symmetry, and the inner tangent point A'2 and the inner tangent point B'2 are in a line-symmetrical positional relationship with the perpendicular line VL2 as the axis of symmetry. The following describes the case where the slab-off region 22 has a line-symmetrical configuration with the perpendicular line VL2 as the axis of symmetry.

[0056] If the line segment X2-O2 connecting the outer tangent point X2 and the center point O2 is taken as the starting line, and the line segment B2-O2 connecting the outer tangent point B2 and the center point O2 is taken as the moving radius, the angle from the starting line to the moving radius in the clockwise direction is called the central angle P2. The central angle P2, which is the starting point of the slab-off region 22 in the main body of the annular device 2, may be 40° to 85°, but in order to reduce the frictional force generated between the surface of the annular device and the back side of the upper eyelid during blinking, for example, it is preferably 50° to 85°, and more preferably 60° to 80°. Similarly, when the line segment X2-O2 is the starting line and the line segment A2-O2 connecting the outer tangent point A2 and the center point O2 is the radius vector, the angle from the starting line to the radius vector in the counterclockwise direction, which is the starting point of the slab-off region 22 in the main body of the annular device 2, may be between 40° and 85°, but is preferably between 50° and 85°, and more preferably between 60° and 80°.

[0057] The annular device 2 includes a slab-off region 23 that is symmetrical to the slab-off region 22 with respect to the horizontal line HL2. The slab-off region 23 preferably has the same configuration as the slab-off region 22, but may have a structure similar to that of the slab-off region 22 in terms of maximum thickness, central angle, etc. The annular device 2 also includes a non-slab-off region 33 that is symmetrical to the non-slab-off region 32 with respect to the vertical line VL2. The non-slab-off region 33 preferably has the same configuration as the non-slab-off region 32, but may have a structure similar to that of the non-slab-off region 32 in terms of maximum thickness, central angle, etc.

[0058] As long as the annular device 2 has the above-described configuration, other configurations may be set as appropriate. On the other hand, from the viewpoint of ease of handling, i.e., reducing the frictional force generated between the annular device and the palpebral conjunctiva during blinking, suppressing the effects of this frictional force and thereby suppressing slippage and rotational movement of the annular device, while maintaining a certain shape retention and making the annular device easier to wear, it is preferable that the area ratios of the slab-off regions 22 and 23 to the non-slab-off regions 32 and 33 of the annular device 2 be in a constant relationship. For example, the total surface area of ​​the slab-off regions 22 and 23 is preferably 20% to 90%, more preferably 25% to 85%, even more preferably 50% to 80%, and even more preferably 60% to 80% of the total surface area of ​​the main body of the annular device 2 (the total surface area of ​​the slab-off regions 22, 23, non-slab-off regions 32, and non-slab-off regions 33).

[0059] Preferably, the annular device 2 has a shape in which the non-slab-off regions 32 and / or 33, the slab-off regions 22 and / or 23 have their greatest thickness midway between the inner and outer edges.

[0060] For example, the non-slab-off region 32 has a continuous configuration of an inner edge portion 321 (or 331), an intermediate portion 322 (or 332), and an outer edge portion 323 (or 333), and it is preferable that any part of the intermediate portion has the maximum thickness, and that the thickness is gradually reduced from the part having the maximum thickness in the intermediate portion toward the outer edge.

[0061] Similarly, for example, the slab-off region 22 preferably has a continuous inner edge portion 221, an intermediate portion 222, and an outer edge portion 223, and preferably has the maximum thickness in any part of the intermediate portion. More preferably, the thickness gradually decreases from the maximum thickness in the intermediate portion toward the outer edge. However, depending on the maximum thickness in the intermediate portion 222, the thicknesses of the inner edge portion 221 and the outer edge portion 223 may become too small, which may reduce the shape retention and handleability of the annular device. Therefore, the inner edge portion 221, the intermediate portion 222, and the outer edge portion 223 may have a uniform thickness. The same applies to the slab-off region 23.

[0062] The widths of the portions corresponding to the inner and outer edge portions of the annular device 2 may be set as appropriate, and for example, the inner edge portions 221, 231, 321, and 331 each preferably have a width of 0.3 mm to 0.5 mm from the inner contact point on the inner peripheral edge of the opening side of the annular device 2 toward the outer peripheral edge. The outer edge portions 223, 233, 323, and 333 each preferably have a width of 0.3 mm to 0.5 mm from the outer contact point on the outer peripheral edge of the annular device 2 toward the inner peripheral edge. The intermediate portions 222, 232, 322, and 332 are the remaining portions of the annular device 2 excluding the inner and outer edge portions.

[0063] One embodiment of the second type of annular device is shown in FIG. 2B, which has two circumferential grooves on the rear surface.

[0064] [Materials for the Annular Device] The cyclic device of one embodiment of the present invention is made of a hydrogel. The hydrogel is based on a polymer of monomer components including a hydrophilic monomer. The hydrogel swells with an aqueous liquid such as water or a solution containing water within the polymer matrix and retains the aqueous liquid. Note that a polymer is formed by the polymerization of monomers, and the constituent units derived from each monomer in a polymer are also called residues and moieties.

[0065] Specific examples of hydrogels include hydrogels produced using hydrophilic monomers, hydrogels produced using hydrophilic monomers and hydrophobic monomers, and hydrogels produced using hydrophilic monomers such as crosslinkable monomers and copolymerizable monomers.

[0066] The hydrophilic monomer can improve the water content of the resulting hydrogel, while the hydrophobic monomer not only adjusts the water content and swelling ratio of the resulting hydrogel, but also allows fine adjustment of the amount of drug contained in the annular device when the annular device is a drug-containing annular device.

[0067] The crosslinking monomer content can control the density of the polymer chains in the resulting hydrogel, and controlling the crosslink density inhibits drug diffusion, delays the release of the contained drug, and thereby controls the drug release rate. In addition to controlling the drug release rate, the crosslinking monomer can also impart physical properties such as mechanical strength, shape stability, solvent resistance, and heat resistance to the resulting hydrogel.

[0068] The hydrophilic monomer may be any monomer having one or more hydrophilic groups in the molecule, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxymethyl (meth)acrylate, hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, glycerol (meth)acrylate, acrylamide, N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N-vinylpyrrolidone, diacetone acrylamide, N-vinylacetamide, (meth)acrylic acid, (meth)acryloxyethyl succinic acid, itaconic acid, methacrylamide propyl triammonium chloride, and 2,3-dihydroxypropyl (meth)acrylate. These monomers may be used alone or in combination of two or more. 2-Hydroxyethyl (meth)acrylate is preferred as the hydrophilic monomer because it can be copolymerized with various monomers and is highly versatile. (Meth)acrylate is a generic term encompassing both acrylate and methacrylate.

[0069] The content of the hydrophilic monomer may be appropriately set, and for example, in order to impart sufficient water retention to the annular device, it is preferably 50% by weight or more relative to the total amount of the monomer components. If the content of the hydrophilic monomer is less than 50% by weight, sufficient water retention cannot be imparted to the annular device, and the flexibility of the annular device may be reduced, which is not preferable.

[0070] The hydrophobic monomer may be any monomer that does not have a hydrophilic group, or that, even if it has a hydrophilic group, is evaluated as being hydrophobic throughout the molecule (i.e., different from a hydrophilic monomer). Examples of the hydrophobic monomer include siloxanyl (meth)acrylate, trifluoroethyl (meth)acrylate, methacrylamide, cyclohexyl (meth)acrylate, n-butyl (meth)acrylate, lauryl (meth)acrylate, and tetrahydrofurfuryl acrylate, and these may be used alone or in combination of two or more.

[0071] The content of the hydrophobic monomer may be appropriately set. The hydrophobic monomer can change the water absorption of the annular device depending on the content. However, if the content of the hydrophobic monomer is too high, the water absorption of the annular device may be significantly reduced, which may reduce the flexibility of the annular device. Therefore, the content of the hydrophobic monomer is preferably less than 30 wt% of the total amount of the monomer components.

[0072] The crosslinkable monomer may be any one having two or more polymerizable groups, and examples thereof include (meth)acrylate-based crosslinkable compounds such as ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and pentaerythritol tri(meth)acrylate; vinyl-based crosslinkable compounds such as allyl methacrylate, diallyl maleate, diallyl fumarate, diallyl succinate, diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, diethylene glycol bisallyl carbonate, triallyl phosphate, triallyl trimellitate, diallyl ether, N,N-diallyl melamine, and divinylbenzene; and these may be used alone or in combination of two or more to impart desired physical properties to the annular device.

[0073] The content of the crosslinkable monomer may be appropriately set, and from the viewpoint of the shape-adjusting effect of the annular device, it is preferably 0.1 to 10% by weight relative to the total amount of the monomer components. If the content of the crosslinkable monomer is less than 0.1% by weight, the mesh structure of the annular device may be insufficient, while if it exceeds 10% by weight, the mesh structure may be excessive, reducing the flexibility of the annular device and making it brittle.

[0074] The annular device may contain various additives added before or after the copolymerization reaction of the monomers. The additives may be selected appropriately, and examples thereof include poly-N-vinyl-2-pyrrolidone (PVP), polyethylene glycol (PEG), polyvinyl alcohol (PVA), poly-N-N-dimethylacrylamide (PDMAA), polyacrylic acid (PAA), polyhydroxyethyl methacrylate (PHEMA), carboxybetaine polymers, phosphobetaine polymers, sulfobetaine polymers, polyglycolic acid (PGA), and polylactic acid (PLA). Depending on the desired physical properties to be imparted to the annular device, one of these may be used alone, or two or more may be used in combination. Preferred additives include PVP, PEG, betaine polymers, PHEMA, PGA, and PLA. The amount of additive added may be selected appropriately depending on the desired physical properties to be imparted to the annular device.

[0075] As an additive, a polymerization initiator used when polymerizing a monomer can be used. Examples of the polymerization initiator include common radical polymerization initiators such as peroxides such as lauroyl peroxide, cumene hydroperoxide, and benzoyl peroxide, azobisvaleronitrile, and azobisisobutyronitrile. These can be used alone or in combination of two or more. The amount of polymerization initiator added may be any amount that promotes the polymerization reaction of the monomer, and is preferably, for example, about 10 ppm to 3,500 ppm relative to the total amount of the monomer components.

[0076] As an additive, an ultraviolet absorber can be added to impart ultraviolet absorption properties to the annular device. Examples of ultraviolet absorbers include 2-hydroxy-4-(meth)acryloyloxybenzophenone, 2-hydroxy-4-(meth)acryloyloxy-5-t-butylbenzophenone, 2-(2'-hydroxy-5'-(meth)acryloyloxyethylphenyl)-2H-benzotriazole, 2-(2'-hydroxy-5'-(meth)acryloyloxyethylphenyl)-5-chloro-2H-benzotriazole, and 2-hydroxy-4-methacryloyloxymethylphenyl benzoate. These can be used alone or in combination of two or more. The ultraviolet absorber can be added in any amount depending on the desired ultraviolet absorption ability to be imparted to the annular device.

[0077] [Method for Manufacturing Annular Device] The annular device according to one embodiment of the present invention can be manufactured by applying a typical method for manufacturing contact lenses, such as a cast molding method or a lace cutting method.

[0078] For example, the cast molding method is a method in which a ring-shaped device is obtained by carrying out a polymerization reaction of monomer components in a mold that is pre-designed to have a desired shape (ring) after polymerization. The lace-cut method is a method in which a block polymer is obtained, and then the resulting block is cut, polished, or the like into the shape of a ring-shaped device to obtain a ring-shaped device. The cast molding method and the lace-cut method will be described in detail below, but the method for producing a ring-shaped device is not limited to these.

[0079] Cast mold manufacturing method A polymerization initiator is added to a mixture of hydrophilic monomers or monomers containing hydrophilic monomers and monomers copolymerizable with hydrophilic monomers, such as hydrophobic monomers and crosslinkable monomers, and the components are stirred and dissolved to obtain a monomer mixture.

[0080] The monomer mixture is placed in a mold made of a material such as metal, glass, or plastic and sealed. The mold containing the monomer mixture is then heated stepwise or continuously in a thermostatic chamber or the like to a temperature in the range of 25°C to 130°C, and the polymerization reaction is carried out for 5 to 120 hours. Photopolymerization using ultraviolet light, electron beams, gamma rays, or the like can also be carried out during the polymerization reaction. Solution polymerization can also be carried out by adding water or an organic solvent to the monomer mixture.

[0081] After the polymerization reaction, the mixture is cooled to room temperature, and the resulting polymer is removed from the mold and processed, as needed, by cutting and polishing. The polymer is then hydrated and swollen using an aqueous liquid to form a hydrogel, yielding a ring-shaped device. Examples of aqueous liquids (swelling liquids) used for hydration and swelling include water, saline, and isotonic buffer solutions, but they may also be mixed with water-soluble organic solvents. Hydration and swelling are preferably achieved by heating the swelling liquid to 40°C to 100°C and immersing the polymer for a certain period of time to quickly bring the polymer into a hydrated and swollen state. Furthermore, the hydration and swelling treatment can remove unreacted monomers contained in the polymer.

[0082] Lace-cut manufacturing method: A block-shaped polymer is obtained using a mold that will have a block shape after polymerization, in a manner similar to that used in the cast molding method. The resulting block is then cut to produce a sclera-corneal lens that covers both the sclera and cornea. An opening large enough to expose the cornea is made in the resulting sclera-corneal lens, and the outer and inner edges are polished to obtain a ring-shaped device. In this case, it is also possible to first open the opening and then cut it into a ring-shaped device.

[0083] [Method of Using the Annular Device] The annular device of one embodiment of the present invention is worn in an area that can cover the sclera, i.e., on the surface of the sclera, more specifically, on the surface of the bulbar conjunctiva that covers the sclera. A dedicated aid may be used for wearing, but it may also be worn by holding it between fingers, placing it around the bulbar conjunctiva, and then fitting it with the fingers to cover the bulbar conjunctiva.

[0084] The annular device of one embodiment of the present invention can be used as an annular device for sustained drug release. In this case, the amount of drug administered to ocular tissue by the annular device can be appropriately set, depending on the type of drug, but is typically about 1 μg to 100 mg per administration. The number of drug administrations, i.e., the number of times the annular device of one embodiment of the present invention is worn, can be appropriately selected depending on symptoms, age, etc., and can be, for example, one to multiple times per day (e.g., one to six times), although the annular device may also be worn on the eye once every few days to several months.

[0085] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples, and the present invention can take various forms as long as the object of the present invention can be solved.

[0086] [Method for Fabricating Annular Devices] A monomer mixture solution was prepared by mixing 99 g of 2-hydroxyethyl methacrylate as a hydrophilic monomer, 1 g of ethylene glycol dimethacrylate as a crosslinking monomer, and 0.15 g of 2,2'-azobisisobutyronitrile as a polymerization initiator. The monomer mixture solution was added to a mold designed to obtain an annular device of the size and structure shown in Examples 1 to 13 and Comparative Example 1 in Table 1. The mold containing the monomer mixture solution was subjected to a thermal polymerization treatment (under a nitrogen atmosphere, heated from room temperature to 100°C for 40 hours). After the thermal polymerization treatment, the polymer obtained from the mold was subjected to a swelling treatment by heating in physiological saline at 60°C for 30 minutes, followed by autoclaving to obtain an annular device. Note that the thickness of the slab-off region in Table 1 refers to the maximum thickness along the line X1-X'1 in Figure 1A or the line X2-X'2 in Figure 2A. The thickness of the non-slab-off region in Table 1 refers to the maximum thickness along the line segment Y1-Y'1 in FIG. 1A or the line segment Y2-Y'2 in FIG. 2A. Examples 1 to 13 have a line-symmetric structure with respect to the vertical line VL1 or VL2 as the axis of symmetry. Examples 6 to 13 have a line-symmetric structure with respect to the horizontal line HL2 as the axis of symmetry.

[0087] The thickness of the annular device was measured by measuring the cross section of a slice obtained by cutting the annular device in the radial direction using the measurement mode of a digital microscope ("VHX-6000"; manufactured by Keyence Corporation).

[0088] [Sensory evaluation method] The subjects were asked to evaluate the wearing sensation felt when wearing the annular devices of Examples 1 to 13 and Comparative Example 1 according to the following criteria. Similarly, after wearing the annular devices, the inside of the eye was observed with a slit lamp microscope, and the stability of the annular devices on the eyeball was evaluated according to the following criteria.

[0089] Wearing sensation ++: No foreign body sensation and good wearing sensation +: There is a slight foreign body sensation, but it does not interfere with wearing ±: It is possible to wear it, but there is a somewhat strong foreign body sensation -: There is a foreign body sensation that makes it impossible to wear it

[0090] Stability on the eye +: When blinking, the annular device is held stably in the center of the eye. -: When blinking, the annular device slips off the eye or falls off, or is held in a position that completely covers the pupil.

[0091] Furthermore, the ease of handling the annular device when wearing it (ease of wearing it) was evaluated according to the following criteria.

[0092] Handling ++: Easy to put on +: Takes some time to put on ±: Takes a considerable amount of time to put on -: Cannot be put on

[0093] [Evaluation Results] The size and structure of the annular devices, as well as the results of the sensory evaluation, are shown in Table 1. The annular devices of Examples 1 to 13 had at least a partial slab-off region, and therefore were comfortable to wear, stable on the eyeball, and easy to handle. On the other hand, the annular device of Comparative Example 1, which had a ring shape without a slab-off region, was inferior in all aspects of the sensory evaluation, and was found to be particularly unstable on the eyeball.

[0094] Furthermore, in Examples 1 to 5, when the thickness of the lower non-slab-off region was 0.35 mm or more, deformation during handling was small and handling was good. On the other hand, when the thickness ratio of the maximum thickness of the slab-off region to the non-slab-off region was 300% or less, the influence of the eyelids when blinking was small and wearing comfort was good.

[0095] In Examples 6 to 13, when the thickness of the non-slab-off region was 0.50 mm and the thickness ratio of the maximum thickness of the slab-off region to the non-slab-off region was 150% or less, there was an overall feeling of hold and good handling, and surprisingly, the wearing comfort was also good.

[0096] The thickness of a typical contact lens is 0.15 mm, and the maximum thickness of the annular devices described in Patent Documents 1 and 2 is 0.25 mm to 0.38 mm. It has been found that by providing a slab-off region in the annular device and further setting the maximum thickness of the non-slab-off region to 0.40 mm or more, an annular device with good handling properties, wearing comfort, and on-eye stability can be obtained.

[0097]

[0098] 1: First form annular device 2: Second form annular device 21, 22, 23: Slab-off region 211, 221, 231: Inner edge of slab-off region 212, 222, 232: Middle part of slab-off region 213, 223, 233: Outer edge of slab-off region 31, 32, 33: Non-slab-off region 311, 321, 331: Inner edge of non-slab-off region 312, 322, 332: Middle part of non-slab-off region 313, 323, 333: Outer edge of non-slab-off region

[0099] According to the present invention, it is possible to provide an annular device that reduces the frictional force generated between the palpebral conjunctiva and the eyelid when blinking, suppresses its effects, and has excellent stability on the eyeball when worn, thereby suppressing slippage and, as a result, reducing the occurrence of foreign body sensation and eye disorders when worn.Furthermore, according to the present invention, by using such an annular device as a drug-releasing annular device, it is possible to deliver drugs to desired sites on the eyeball, contributing to the health and welfare of individual organisms. CROSS-REFERENCE TO RELATED APPLICATIONS

[0100] This application claims priority from Japanese Patent Application No. 2023-180706, filed October 20, 2023, the entire disclosure of which is incorporated herein by reference. In addition, the entire disclosures of all documents referenced in the detailed description of the invention of this application, including Patent Documents 1 to 3, are incorporated herein by reference.

Claims

1. An annular device for wear on the scleral surface, comprising an opening for exposing the cornea and a body having slab-off and non-slab-off regions formed so that the maximum thickness gradually decreases from the lower end to the upper end.

2. The annular device of claim 1, wherein the slab-off region is axisymmetric with respect to a perpendicular line.

3. The annular device according to claim 2, wherein the slab-off region is formed so that the maximum thickness gradually decreases from the lower end side to the upper end side, starting from a position where the central angle is any angle between 40° and 170°.

4. An annular device for wear on the scleral surface, comprising an opening for exposing the cornea and a body having slab-off and non-slab-off regions formed so that the maximum thickness gradually decreases from the right end side toward the upper and lower ends, and from the left end side toward the upper and lower ends.

5. The annular device of claim 4, wherein the slab-off region is axisymmetric with respect to a normal.

6. The annular device of claim 5, wherein the slab-off region is formed so that the maximum thickness gradually decreases from the right end side toward the upper end side starting from a position where the central angle is any angle between 40° and 85°, and from the right end side toward the lower end side starting from a position where the central angle is any angle between 95° and 140°.

7. An annular device as claimed in any one of claims 1 to 6, wherein the surface area of ​​the slab-off region is between 25% and 70% of the total surface area of ​​the body portion.

8. An annular device as claimed in any one of claims 1 to 6, wherein the maximum thickness of the body in the non-slab-off region is between 120% and 450% of the minimum maximum thickness in the slab-off region.

9. The annular device according to any one of claims 1 to 6, wherein the main body has at least one substantially circumferential groove on its rear surface.

Images