Ophthalmologic imaging method, device and system

Abstract

A light guide for an ophthalmic topography instrument is disclosed. The light guide comprises a light guide body, a topographic map illumination source, a directional optical system and a reflection optical system, wherein the light guide body comprises a reference object; a topographic map illumination source that illuminates a light guide body and a reference wherein the illuminated light guide body guides light for illuminating the eye; a directional optical system housed in the proximal end of the light guide body to guide light from the light guide body across a corneal profile; and a reflective optical system housed in the proximal end of the light guide body that reflects light from the directional optical system that has passed through the light guide body across the corneal profile. An ophthalmic topography instrument including the light guide is also disclosed. Further disclosed is an ophthalmic topography instrument comprising the sclera projection system. A method of determining a topographic map is also disclosed.

Description

[0001] This invention is a divisional application of a patent application with an application date of March 16, 2020, application number 202080030640.0, and invention name “Ophthalmic Imaging Methods, Devices, and Systems”. Technical Field

[0002] The present invention relates to an ophthalmic imaging method, apparatus, and system. More particularly, the present invention relates to an ophthalmic imaging method, apparatus, and system comprising a multifunctional light guide and a sclera measurement system. Background Art

[0003] Corneal topographers measure the geometry of the anterior corneal surface by capturing a reflected image of the cornea from a known illuminated target pattern, imaged on the eye as one or more mires, typically a series of concentric illuminated rings separated by black opaque annuli, known as a Placido system, and analyzing these mires starting from a known position at the corneal apex. A separate system is required to determine the distance from the known reference position of the imaging system to the corneal apex.

[0004] Known corneal topographers direct light through the corneal contour and form an image of the contour on an imaging sensor via one or more mirrors and lens systems.Such profile imaging systems allow the position of the corneal vertex to be measured while acquiring an image of the target reflection.

[0005] Scheimpflug and other projection-type topographic mapping systems, and more recently OCTs (fiber optic cable transmission systems), have been applied to corneal and scleral mapping. With the Scheimpflug method, the high intensity light applied to the retina often causes the sclera to become blurred. Other disadvantages of the Scheimpflug system are the high cost of the instrument and the long acquisition time, which results in a loss of accuracy and thus requires complex registration methods. Both, applying low intensity light to the sclera and applying high intensity light to the retina with a limbal reference have been studied. Projection systems and OCTs can lack accuracy at the important central corneal region and are not economical for many users in the field.

[0006] There is a need for alternative and improved corneal topographers and devices for mapping the cornea and sclera and for efficiently adding additional diagnostic features to topographers to meet the growing demands of the market.

[0007] The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that the prior art forms part of the common general knowledge. Summary of the Invention

[0008] The present invention relates to an ophthalmic imaging method, device and system.

[0009] In one broad form, the present invention is directed to an ophthalmic imaging method, apparatus, and system including a multifunctional light guide.

[0010] In another broad form, the present invention is directed to an ophthalmic topography light guide that illuminates an eye. In yet another broad form, the present invention is directed to an ophthalmic topography light guide or cone that illuminates an eye and transmits light for capture.

[0011] In a first aspect, although it need not be the only or indeed the broadest form, the present invention provides a light guide for an ophthalmic topographer, the light guide comprising:

[0012] a light guide body comprising a reference object; and

[0013] A topographic illumination source illuminates the light guide body and the reference object, wherein the illuminated light guide body guides light for illuminating the eye.

[0014] The illuminated light guide body according to the first aspect may also guide a reference onto the eye surface.The directional reference on the eye surface may comprise a projected reference or image strip.

[0015] The light guide of the first aspect may further comprise:

[0016] a directional optical system housed in the proximal end of the light guide body that directs light from the light guide body across the corneal contour; and

[0017] A reflective optical system, housed in the proximal end of the light guide body, reflects light from the directional optical system that has passed through the corneal contour via the light guide body.

[0018] The reflective optical system may guide the light to one or more capture systems including at least one imaging sensor.The one or more capture systems and / or the at least one imaging sensor may be external to the light guide body.

[0019] In a second aspect, the present invention provides an ophthalmic topographer comprising:

[0020] a light guide body including a reference object;

[0021] a topographic illumination source that illuminates the light guide body and the reference object, wherein the illuminated light guide body directs light for illuminating the eye; and

[0022] An imaging system that images a reference object projected onto the surface of the eye through a central channel in the light guide body.

[0023] In a third aspect, the present invention provides an ophthalmic topographer comprising:

[0024] a light guide body including a reference object;

[0025] a topographic illumination source that illuminates the light guide body and the reference object, wherein the illuminated light guide body directs light for illuminating the eye;

[0026] an imaging system that images a reference object projected onto the surface of the eye through a central channel in the light guide body;

[0027] a directional optical system housed in the proximal end of the light guide body that directs light from the light guide body across the corneal contour; and

[0028] A reflective optical system, housed in the proximal end of the light guide body, reflects light from the directional optical system that has passed through the corneal contour via the light guide body.

[0029] The imaging system according to any of the above aspects may comprise one or more lenses.The imaging system may direct light onto one or more capture systems.

[0030] The reflective optical system according to any of the above embodiments may reflect light for capture on at least one imaging sensor.

[0031] In a fourth aspect, the present invention relates to a light guide for an ophthalmic topographer, the light guide comprising:

[0032] A light guide body comprises a reference object, wherein the light guide body guides light towards the reference object.

[0033] The light guide according to the fourth aspect may further comprise an illuminating light guide body and a topographic illumination source of the reference object, wherein the illuminating light guide body guides light for illuminating the eye.

[0034] The light guide body according to any of the above aspects may further include a substantially symmetrical shape and / or a contoured portion at the proximal end. The contoured portion may include symmetrical and opposing extensions and recesses to achieve close proximity of the eye to the reference object and thus achieve wide eye coverage. The extensions may accommodate the directional optical system and the reflective optical system. The extensions and / or recesses may be arranged at opposing points on the light guide body at the proximal end. The extensions and / or recesses may include scalloped edge portions.

[0035] According to any of the above aspects, at least a portion of the directional optical system and at least a portion of the reflective optical system may be arranged on opposite sides of the light guide body. In one embodiment, the directional optical system is arranged on the left side relative to the operator, and the reflective optical system is arranged on the right side relative to the operator. In other embodiments, the directional optical system is arranged on the right side, top, or bottom relative to the operator, and the reflective optical system is arranged on the left side, bottom, or top relative to the operator.

[0036] According to any of the above aspects, the directional optical system and the reflective optical system reflect light substantially at right angles, and the two propagation directions vector intercept the axis of the central channel at right angles.

[0037] According to any one of the above aspects, the light guide body may include a directional optical system housing and a reflective optical system housing.The directional optical system housing and the reflective optical system housing may be arranged in corresponding and opposite extensions.

[0038] The topographer according to any of the above aspects may further include one or more capture systems. The one or more capture systems may include at least one imaging sensor, such as a CCD (charge-coupled device) or a CMOS (complementary metal-oxide-semiconductor (CMOS) image sensor). The one or more capture systems may include a topographic map capture system and a contour capture system. The topographic map capture system may be used in topographic mapping using a reference object. The contour capture system may be used in eye contour analysis using light guided by a reflective optical system. In another embodiment, the one or more capture systems include at least one imaging sensor for topographic mapping and eye contour analysis.

[0039] The ophthalmic topographer according to any of the above aspects may further comprise:

[0040] One or more optical systems for imaging the eye.

[0041] One or more optical systems may be arranged in the optical path to image the eye.

[0042] In an embodiment, when the one or more optical systems include two or more optical systems, the topographer may further include a positioner for selectively positioning each optical system included in the two or more optical systems in the optical path. Each optical system in the two or more optical systems may include an interchangeable optical system in the optical path for imaging the eye.

[0043] The positioner may include a wheel on which each of the two or more interchangeable optical systems may be positioned. The wheel may include one or more indexing positions for precise positioning of each of the two or more optical systems. The positioner may include a playless positioner. The positioner may include one or more teeth. The wheel may include a gear. The positioner may include one or more actuators, such as electric motors.

[0044] The wheels may include one or more perforations for a central topographic mapping system.

[0045] In one embodiment of any of the above aspects, the topographer includes an illumination array including a topographic illumination source and a contour optics illumination source. The topographer illumination source may include a distributed light source. The distributed light source and the contour optics illumination source may be distinguishable or distinguishable. The distributed light source and the contour optics illumination source may emit light at sufficiently different wavelengths so as not to interfere with each other in their respective imaging paths.

[0046] The distributed light source may include a plurality of light-emitting diodes (LEDs). The distributed light source may emit a broadband visible spectrum. Each of the plurality of LEDs may include a red, green, and blue (RGB) LED. Each RGB LED may include a separate narrow wavelength band. Each of the plurality of LEDs may generate white light. In certain embodiments, the plurality of LEDs may include an array arranged as two or more LED rings. The two or more LED rings may be included on a printed circuit board.

[0047] The contour optics illumination source may emit infrared light. The contour optics illumination source may include a point light source. In one embodiment, the contour optics illumination source is an LED.

[0048] In yet another embodiment of any of the above aspects, a portion of the optical path of the distributed light source and a portion of the optical path of the contour optics illumination source illuminate the surface of the eye.

[0049] The topographic illumination source and / or the contour optic illumination source may be disposed at the distal end of the light guide body.

[0050] In one embodiment of any of the above aspects, the reference comprises a plurality of rings. The reference may comprise a Placido disk comprising a plurality of concentric rings. The plurality of concentric rings may comprise alternating transparent and opaque rings. The transparent rings may be illuminated. The transparent rings may be integral with the light guide body. The concentric rings may be arranged along the length of the inner surface of the light guide body. The reference may comprise a covering comprising opaque rings. The opaque rings may be arranged to be linearly separated by transparent sections. The reference may be sprayed or otherwise arranged on the light guide body. The spraying or other application may comprise applying only the opaque rings.

[0051] In another embodiment of any of the above aspects, the light guide body may include a plurality of segments, each segment including a respective transmission coefficient. The selectable transmission coefficients provide uniform illumination along the length of the reference object. Each segment may include any number of transparent rings and opaque rings. Each light guide segment may include an optically isolating outer surface or cover. In one embodiment, a segment may be colored to provide a visual target. In another embodiment, a segment or light guide body includes a color filter that provides a visual target. The colored segment or color filter may be green. The color filter may include a polymer film in the light path. The visual target or target segment may be arranged at the distal end of the light guide body. The visual target or target segment may transmit colored light. The light guide body may include two, three, four, five, six, seven, eight, nine, or ten segments. In one embodiment, the light guide body includes three segments. The number of segments may be selected to provide adequate illumination.

[0052] In yet another embodiment of any of the above aspects, the light guide body may include an optical medium having a transmission coefficient different from air for light propagation.

[0053] In another embodiment of any of the above aspects, the light guide body includes a substantially conical or toric shape. The substantially conical shape may include a frustoconical shape. The conical or toric shape may include an internal channel. The outer surface may include a curved or toric shape, and the internal channel may include a substantially conical shape.

[0054] In another embodiment of any of the above aspects, the light guide body is illuminated in a selective color depending on the light emitted by the illumination array. The light emitted by the illumination array may include white, red, green, blue, or infrared light. The visual indication of the modality may include light pulses for the selected color or varying brightness or intensity. The frequency, modulation, or duration of the light pulses may vary. The brightness or intensity may vary depending on the modality.

[0055] In yet another embodiment of any of the above aspects, the directional optical system and the reflective system are positioned on substantially opposite spots of the light guide body.

[0056] The directional optical system may include one or more prisms arranged between the light source and the exposed eye. The prisms may include diffusing prisms.

[0057] The reflective optical system may include one or more mirrors.

[0058] In another embodiment, the directional optical system may include a mirror and the reflective optical system may include a prism.

[0059] In another embodiment of any of the above aspects, the light guide body includes a transparent medium. The transparent medium may include one or more optically homogeneous and transparent media. The medium may include acrylic, such as poly (methyl methacrylate) (PMMA).

[0060] In a further embodiment of any of the above aspects, light targeted by the reflective optical system is incident on a profile imaging system arranged at a distal end of the light guide body.

[0061] In another embodiment of any of the above aspects, the profile imaging system includes one or more of a focusing lens system and a filter that transmits only light from the profile optics illumination source.

[0062] In yet another embodiment of any of the above aspects, the profile imaging system focuses target light onto the one or more capture systems.The focused target light includes information about a distance of the subject's eye from a reference point.

[0063] In yet another embodiment of any of the above aspects, the contour imaging system focuses a contour plane of the eye onto one or more capture systems.

[0064] The inner and outer surfaces of the light guide body may be polished. The polishing may achieve a desired reflection compared to a residual scattering of the propagating light of the light source.

[0065] In another embodiment of any of the above aspects, a portion of the contour light path is contained within the light guide body. The contour light path and the internal contour light path may include a directional optical system and a reflective optical system. The directional optical system guides light across the contour of the eye to the reflective optical system. The reflective optical system guides the light to the focusing optical system and / or one or more capture systems.

[0066] In another embodiment of any of the above aspects, light from the topographic illumination source propagates along two or more optical paths through the light guide body. The two or more optical paths may include two or more of: light that is completely coupled out of the light guide body; light that is partially coupled out of the light guide body and partially incident on the eye; and light that is completely incident on the eye. In embodiments where the outer surface of the light guide body is painted or otherwise coated, light that is completely coupled out of the light guide body may not exist. Light that is incident on the eye may then pass through the central channel and be incident on one or more capture systems.

[0067] According to any of the above embodiments, a reflective optical system and a directional optical system for imaging the eye contour are included in the contour system.

[0068] In another embodiment of any of the above aspects, the light guide body includes a reference; a contour system; and the light guide body provides the necessary optical input to image the topography of the corneal surface.

[0069] In a further embodiment of any of the above aspects, the light guide body comprises at least a portion of a central mapping system, the central mapping system comprising: the light guide body; a mapping illumination source; a reference object and a mapping imaging system. The central mapping system may also be one or more capture systems.

[0070] According to any of the above embodiments, the ophthalmic topographer may include a corneal topographer. According to this embodiment, the surface of the eye includes a corneal surface; the eye contour includes a corneal contour; the illumination of the eye includes illumination of the cornea; and the eye covering includes a corneal covering.

[0071] According to any of the above aspects, the topographer may further include a sclera measurement device. The sclera measurement device may include one or more sclera projection systems. Each of the one or more sclera projection systems may include a sclera projection light source and a sclera reference object.

[0072] Each scleral reference can include at least one aperture, the at least one aperture comprising one or more apertures. The one or more apertures can be arranged in an aperture pattern. The one or more apertures can include a scleral aperture pattern and, optionally, a corneal aperture pattern. When imaged on the eye or at least one imaging sensor, the scleral aperture pattern can be imaged as one or more scleral locators, and the corneal aperture pattern can be imaged as a corneal scatter image.

[0073] Each of the one or more scleral projection systems may further include a scleral projection imaging system. The scleral projection imaging system may include one or more lenses.

[0074] One or more scleral projection systems can be symmetrically mounted on the topographer. The symmetrically mounted scleral projection systems can include scleral projection systems mounted on either side of the topographer. In one embodiment, the scleral projection systems are arranged on either or both sides of the light guide, i.e., a symmetrically mounted left scleral projection system and a symmetrically mounted right scleral projection system. This allows the aperture pattern to be projected onto different portions of the eye surface.

[0075] The scleral aperture pattern illuminated by the scleral projection light source can be imaged onto the projection imaging system and onto the sclera portion of the eye surface. The corneal aperture pattern illuminated by the projection light source can also be imaged onto the projection imaging system and onto the cornea.

[0076] The sclera measurement device may further include one or more sclera registration reference projectors. The sclera registration reference projectors may include a sclera reference light source and a sclera registration reference. The sclera reference may include a registration reference light guide, which may optionally be provided in the form of two or more concentric rings and may include a second Placido disk.

[0077] Light from the scleral reference light source and passing through the scleral registration reference can be reflected from the surface of the eye and imaged by the imaging system onto one or more image capture systems.

[0078] Light from the scleral reference light source, passing through the scleral registration reference and reflected from the surface of the eye can form a scleral image. The scleral image can be digitally processed to obtain corneal height information and scleral position, and the scleral image can include scleral height information.

[0079] The processed scleral image can be used to combine corneal height information from the topographer with scleral height information to form a new scleral topography map. This combination can include image registration. The registration can utilize one or more of a scleral locator, a corneal scatter image, and a scleral registration reference image.

[0080] At least one aperture may include two or more adjacent registration apertures through which light from the scleral reference light source can pass and propagate to be positioned on the cornea. In one embodiment, the two or more adjacent registration apertures include corresponding groups of one or two or more adjacent transparent circular dots. In another embodiment, the adjacent registration apertures include a group of one or two or more adjacent alternating transparent and opaque rings concentric with the axis of the central channel, thereby forming a second Placido disk. In a specific embodiment, the two or more adjacent apertures include three transparent circular rings. In yet another embodiment, the three transparent circular rings can serve as the reference aperture and can be used in conjunction with alternating transparent and opaque rings.

[0081] The projected scleral aperture pattern and the registration stop on the eye surface can be imaged together on the same image onto one or more capture systems. From the two adjacent locators or point-shaped pieces of the registration stop, curvature and height information of the reflected eye surface can be derived.

[0082] One or more scleral reference apertures and / or scleral registration apertures may be imaged onto the one or more imaging sensors by the imaging system.

[0083] The sclera measurement device can further apply an algorithm to improve the accuracy of the sclera height information by comparing the eye reference axis of the sclera image with the eye reference axis of the cornea image. The reference axis can include the axis of the eye relative to the central channel or the rotation information between the eye and the central channel.

[0084] In one embodiment, the light guide body and the topographic illumination source can form a corneal reference. In a preferred embodiment, the corneal reference includes a corneal reference projected by the light guide body and a topographic illumination source for the vertex and a corneal aperture pattern for additional corneal reference information.

[0085] In yet another embodiment, the pupil may be captured in both the sclera image and the cornea image, wherein the captured pupil information may provide information of an eye reference axis for additional cornea reference information.

[0086] In yet another embodiment, other uniquely identifiable scleral features may be used to combine corneal and scleral height information.

[0087] In another embodiment, the pupil center position of the eye relative to the axis of the central channel can be measured to provide reference data for combining corneal and scleral height information.

[0088] In a fifth aspect, the present invention provides a method of determining an ophthalmic topography, the method comprising:

[0089] illuminating a light guide body containing a reference object to project the reference object onto an anterior surface of the cornea, wherein the illuminated light guide body projects light for illuminating the cornea;

[0090] directing light from the light guide body through the corneal contour using a directional optical system housed in the proximal end of the light guide body;

[0091] reflecting, by means of a reflective optical system housed in the proximal end of the light guide body, the light from the directional optical system that has passed through the corneal contour via the light guide body;

[0092] capturing the reflected light on at least one imaging sensor external to the light guide body; and

[0093] A reference object projected onto the corneal surface through a central channel in the light guide body is captured to determine corneal topography.

[0094] The method of the fifth aspect may further include:

[0095] imaging an aperture pattern projected onto a surface of the eye by one or more projection lens systems, wherein the aperture pattern projects at least one scleral reference and at least one corneal reference; and

[0096] The sclera height information is combined with the determined cornea height information.

[0097] According to any of the above aspects, the light guide may include a multifunctional light guide. The multifunctionality may include an imaging function and a contour optics function, the imaging function including directing light onto the eye for imaging the eye, the contour optics function including contour imaging the outer shape of the eye. The multifunctionality and imaging function may also include a topographic optics function including imaging the topography of the eye.

[0098] According to any of the above aspects, the light guide may comprise a topographic cone.

[0099] According to any of the above aspects, the topographer includes one or more of a housing and a base plate. The topographer may also include a subject support including one or more of a chin support and a forehead support. The topographer may further include an adjustment arm to move the chin support up and down. The subject support may also include a calibration device attachment to which a calibration device may be attached for calibrating the topographer. The topographer may also include a manually operated positioner, such as a joystick. The manually operated positioner may move the base unit on two axes: laterally and forward and backward. The topographer may also be moved vertically, such as by rotation of a joystick. Vertical movement may be performed by a mounting post on which light guides and other components (such as a topographic illumination source, a contour imaging system, and a topographic imaging system) are mounted.

[0100] According to any of the above aspects, the topographer may be connected to the junction box via a topographer cable.The junction box may be connected to the computer via a computer cable and to a power source.

[0101] According to any of the above aspects, the topographer may further comprise a printed circuit board for controlling the topographer and / or communicating with a computer.The printed circuit board may be arranged on the mounting post.

[0102] According to any of the above aspects, the topographer may further include an external illuminator. The external illuminator may provide light for the interchangeable optical system. The external illuminator may include symmetrically mounted light sources. The symmetrically mounted light sources may be arranged on either side of the light guide, i.e., a symmetrically mounted left light source and a symmetrically mounted right light source. The light sources may be any suitable light source, such as an LED.

[0103] The housing may be a protective enclosure surrounding the base unit, the vertical mounting post, at least a portion of the light guide body, the external illumination device, and one or more of the components of the sclera measurement device.

[0104] Other aspects and / or features of the present invention will become apparent from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0105] In order that the present invention may be readily understood and put into practice, reference will now be made to the accompanying drawings, wherein like reference numerals refer to like elements, to illustrate embodiments of the present invention. The accompanying drawings are provided by way of example only, in which:

[0106] Figure 1A and Figure 1B is a schematic diagram showing an embodiment of a corneal topographer according to the present invention. Figure 1A is a stereogram of the topographer, and Figure 1B A close-up view of the cone and cone shell is shown.

[0107] Figure 2A and Figure 2B is a schematic diagram showing a cross-sectional view of one embodiment of the topographer of the present invention.

[0108] Figure 3A 、 Figure 3B 、 Figure 3C and Figure 3D is a schematic diagram illustrating one embodiment of a positioner for positioning a lens system.

[0109] Figure 4 is a schematic diagram showing a positioner according to another embodiment of the present invention.

[0110] Figure 5 is a schematic diagram showing a cross-sectional view and an optical path of a prior art device for acquiring corneal profile data.

[0111] Figure 6 is a schematic diagram showing another cross-sectional view and optical path for acquiring sclera data according to an embodiment of the present invention.

[0112] Figure 7A 、 Figure 7B 、 Figure 7C and Figure 7Dis a diagram showing an example of a contour image (left) and an example of a cornea image (right) ( Figure 7A ); representation of an eye showing a reference image ( Figure 7B ); Representation of an eye photographed with illumination provided by an external illuminator ( Figure 7C ); Representation of an eye wearing a contact lens and visualized using fluorescein ( Figure 7D ; and a representation of an eye showing the meibomian glands ( Figure 7E )).

[0113] Figure 8A and Figure 8B FIG. 1 is a diagram illustrating a corneal topography optical path according to an embodiment of the present invention. Figure 8A ) and corneal contour light path ( Figure 8B ) is a schematic diagram of a cross-sectional view.

[0114] Figure 9 is a schematic diagram showing a cross-sectional view illustrating the light path of corneal topography and corneal contour with additional external illumination according to one embodiment of the present invention.

[0115] Figure 10 is another schematic diagram showing a cross-sectional view illustrating the optical paths of corneal and scleral topography according to one embodiment of the present invention.

[0116] Figure 11A and Figure 11B FIG. 1 is a schematic diagram showing an optical path for image registration according to an embodiment of the present invention.

[0117] Figure 12A and Figure 12B FIG. 1 is a schematic diagram illustrating an orientation reference object used for image registration according to an embodiment of the present invention.

[0118] Figure 13 is a schematic diagram showing a front view of a topographer according to one embodiment of the present invention.

[0119] Figure 14A and Figure 14B A commercial embodiment of a light guide and topographer according to the present invention is shown.

[0120] It should be understood by those skilled in the art that the elements in the drawings are shown for simplicity and clarity and are not necessarily drawn to scale. For example, the relative sizes of some elements in the drawings may be distorted to help improve understanding of the embodiments of the present invention. DETAILED DESCRIPTION

[0121] Embodiments of the present invention relate to an improved ophthalmic topography lightguide and an improved ophthalmic topographer. Those skilled in the art will readily appreciate that lightguides, such as those used for topography, are also referred to as "cones." This is because such lightguides are typically conical in shape. The lightguide of the present invention has a substantially conical inner surface; however, the outer surface is not conical. Given the convention and terminology used in the art, the terms lightguide and cone are used interchangeably herein.

[0122] The inventors have surprisingly discovered that by integrally including a reference object within a light-emitting corneal topography lightguide, the reference object can form part of both the lightguide body and the imaging system. This has significant advantages, as the lightguide body can be smaller and the light-guiding functionality can be provided by the lightguide body, making the lightguide body more cost-effective and enabling additional imaging modes and improved corneal topography performance. Another advantage of one embodiment of the present invention is that contour optics can be provided within the lightguide body.

[0123] In another embodiment, the present invention provides multifunctional topography by providing a gapless interchangeable lens system. The ability to use a single lens for each interchangeable system optic means that more control can be exercised over each lens design and overall quality can be improved.

[0124] Additionally, the ophthalmic topographer offers, for the first time, scleral topography capabilities and methods. This is accomplished while maintaining high-quality corneal topography, and can be combined with additional data from scleral topography. This can lead to better quality and improved contact lens fitting. Furthermore, no fluorescein is required to obtain corneal or scleral topographic information, a significant advantage for the user and benefits patient comfort when compared to existing technologies.

[0125] As used herein, an "optical system" means one or more lenses or other imaging components, mirrors, prisms, spectral filters, and / or apertures for directing, observing, analyzing, recording, and / or capturing light. It should be understood that a particular optical system may be composed of different arrangements of one or more lenses or other imaging components, mirrors, prisms, spectral filters, and / or apertures and perform the same function. For example, where a particular optical system is described herein as including one or more prisms, it should be understood that a different configuration including one or more lenses or other imaging components, mirrors, prisms, spectral filters, and / or apertures may be substituted for the prism.

[0126] As used herein, "imaging system" means a specific type of optical system that forms a real or virtual image of an object.

[0127] As used herein, a "mire" is a pattern of reference objects whose image, as reflected by the curved surface of the cornea, is used to calculate the topography of the cornea.

[0128] As will become apparent from the following description, the light guide or cone of the present invention is a multifunctional light guide or cone. As used herein, "multifunctional light guide or cone" is intended to refer to a light guide or cone that performs more than one optical function. In one embodiment, the multifunctional light guide body directs light and an image strip toward the eye for imaging the image strip onto an imaging sensor, and also includes a profile optical system for imaging the contour of the eye.

[0129] In general, one embodiment of the present invention is directed to a cone-shaped or light-guiding body that includes a reference for a topographer.

[0130] In another embodiment, the present invention relates to a light guide or cone comprising a reference object, a contour optical system for imaging the contour of an eye, and a topographic optical system for imaging the corneal surface, wherein the illuminated reference object 103 is imaged as an image strip on the eye and on the imaging sensor.

[0131] As will be explained below, in one embodiment, the present invention also provides an interchangeable optical system to allow more than one operating modality and imaging function to be performed.

[0132] One embodiment of a topographer 100 according to the present invention is shown in FIG1 . The topographer 100 includes a topograph light guide or cone 101 housed in a housing 121 . A base plate 120 provides stable support. A stable platform is provided by a subject support 122 , which includes a chin rest 117 and a forehead rest 118 . An adjustment arm 119 is also provided for moving the chin rest up and down. This vertical adjustment allows different head sizes to be accurately aligned so that the height of the eye 106 is aligned with the optical axis of the topographer 100 .

[0133] The topographer 100 is connected to a junction box 160 (not shown) via a topographer cable 214. The junction box 160 is in turn connected to a conventional computer 161 (not shown) via a computer cable 162 (not shown) plugged into a USB (Universal Serial Bus) port, and to a power source 163 (not shown) via a power cable 164 (not shown).

[0134] The subject support 122 also includes a calibration device attachment 165 (not shown) to which a calibration device 166 (not shown) can be attached for use in calibrating the topographer 100 .

[0135] The topographer 100 also includes a manually operated positioner 167 that includes a joystick 168 that can be used to move the base unit 169 on two axes, sideways and forward and backward. In addition, vertical movement is achieved by rotating the joystick 168. This allows for accurate and convenient alignment of the topographer 100 with the subject's eye 106. Vertical movement is achieved via a mounting post 169, to which the light guide 101 and other components (such as the light guide illumination array 155, the contour imaging system 112, and the topographic imaging system 123) are mounted.

[0136] As will be described in further detail below, the topographer 100 also includes an external illuminator 207 that provides additional light for topographic mapping and for additional ophthalmic imaging functions. The external illuminator 207 includes light sources 208 symmetrically mounted on either side of the light guide 101. The light sources 208 can be any suitable light source, such as an LED.

[0137] Further described below are optional aspects of the sclera measurement device 400 that may be included in some embodiments of the topographer 100. The sclera measurement device 400 includes Figure 10 and Figure 11A One or more scleral projection systems 401 and scleral references 402 are shown in FIG. The sclera measurement device may further include one or more scleral registration reference projectors 404.

[0138] As also described in further detail below, the imaging system 123 also includes one or more actuators 307 (not shown), such as motors, that rotate the wheel 302 to a defined position for alignment in the imaging system optical path.

[0139] Also disposed on the mounting post 169 is a printed circuit board 170 (not shown) for controlling the topographer 100 and communicating with the computer 161. Figure 1A and Figure 1B As shown, all internal components are enclosed in a housing 121 which forms a protective enclosure around the base unit 169 and the vertical mounting posts 170. Additionally, the light guide body 102 is partially enclosed within the housing 121.

[0140] Figure 1B Shown is a portion of a light guide 100 and a profile imaging system 112. The light guide 100 comprises a light guide body 102 comprising at least a portion of a reference object 103 that is illuminated to image a relief ring or annulus as an image strip 126.

[0141] The light guide body 102 includes a transparent medium 104. In the embodiment shown in FIG2 , the transparent medium 104 includes poly(methyl methacrylate) (PMMA). Based on the teachings herein, a skilled person can readily select any other suitable transparent medium. The transparent medium 104 can include one or more optically uniform and transparent media.

[0142] The light guide body 102 includes a substantially toric or conical outer surface 142 and a substantially conical inner surface 141. In the embodiment shown in the figures, the substantially toric or conical shape is a toroidal or frustoconical shape that includes a central channel 124. The diameter of the cone 101 decreases along its length from the distal end 115 to the proximal end 109. The toric or conical shape means that the distal end diameter is greater than the proximal end diameter, such that the concentric transparent ring 128 and the opaque ring along the length of the light guide body 102 decrease in circumference from the distal end 115 to the proximal end 109.

[0143] The light guide body 102 is conveniently sized to fit the shape of a person's face, wherein the diameter of the aperture of the central channel is less than 35 mm, the overall diameter of the light guide body 102 is less than 70 mm, and the length of the light guide body 10 is less than 100 mm. The depth of the topographer 100 is less than 300 mm and the height of the topographer 100 is less than 450 mm.

[0144] In another embodiment, the light guide body 102 is substantially symmetrical and includes a contoured portion 125 (not shown) at the proximal end 109. The contoured portion 125 includes symmetrical and opposing extensions 145 (not shown) and recesses 146 (not shown). The extensions 145 accommodate at least a portion of the directional optical system 108 and at least a portion of the reflective optical system 111. The extensions 145 are disposed at opposing points of the proximal end 109. The recesses 146 are also disposed at opposing points of the proximal end 109. The extensions and recesses may include scalloped edge portions.

[0145] In another embodiment of any of the above aspects, at least a portion of the directional optics and at least a portion of the reflective optics are positioned opposite each other on the proximal end of the light guide body.Notably, the directional optics directs light at right angles to the optical axis.

[0146] The light guide 101 is attached to the topographer 100 by a mounting flange 147 (not shown). The toric or conical shape of the light guide body 102 accommodating the central channel 124 allows the eye 106 to be exposed to a reference 130 disposed on the inner surface 141 .

[0147] Figure 1BA front perspective view of a portion of the topographer 100 is shown, showing a close-up of the area including the light guide 101 and making the reference object 103 visible through the central channel 124 .

[0148] like Figure 1B Stereoscopic image and Figure 2A As shown in the cross-sectional view of FIG, the reference 130 includes alternating transparent rings 128 and opaque rings 129 (in FIG. Figure 2A In the embodiment shown, reference 130 includes a plurality of rings or annular members (shown as dashed lines in the cross-sectional view of FIG. 1 ). In the illustrated embodiment, reference 130 includes a plurality of transparent rings 128, each of which is adjacent to an opaque ring 129 on both sides and is arranged along its axial length on inner surface 141. The transparent rings 128 and opaque rings 129 at the ends will only be adjacent to the opaque rings 129 and transparent rings 128 at the non-end sides.

[0149] When the light guide 101 is illuminated, the plurality of transparent rings 128 are illuminated and form a virtual image of concentric rings, such as the image strips 126, produced by the curvature of the anterior corneal surface 148. By imaging and analyzing the imaged concentric annular image strips 126 produced by the transparent rings 128 and produced by the anterior corneal surface 148 via the imaging system 123, the topography of the cornea 107 can be determined. In this regard and in the present embodiment, the reference object 103 can be referred to as a Placido disk.

[0150] The inner surface 141 faces the central channel 124. The inner surface 141 and the outer surface 142 of the light guide body 102 may be polished so as to function as reflective or refractive optical surfaces.

[0151] The transparent ring 128 is integral with the light guide body 102. In the illustrated embodiment, the reference 103 is (or more accurately, the opaque ring 129) sprayed or otherwise applied to the light guide body 102. In another embodiment, the spraying (or other application) may include the application of the opaque ring 129 and the transparent ring 128. In yet another embodiment, the reference 103 may include a cover 149 (not shown) comprising a transparent sheet 151 on which the opaque ring 134 is included. In this embodiment, the opaque ring 129 may be printed on the sheet 151. The cover 149 is then positioned within the central channel 124 so that the printed opaque ring 129 extends along the length of the central channel 124.

[0152] exist Figure 1A and Figure 1BIn the embodiment shown in FIG, reference object 103 includes thirty transparent rings 128. Based on the teachings herein, one skilled in the art will readily be able to select other suitable reference objects and other suitable numbers of image stripe generating features. For example, reference object 103 may include 5 to 50, 10 to 40, or 20 to 35 transparent rings or other image stripe generating features.

[0153] Figure 2A and Figure 8A It is also shown that in order to provide uniform illumination of the ring 126, the light guide body 102 may include a plurality of light guide segments 130. Figure 2A and Figure 8A In the embodiment shown, the light guide body 102 includes three segments 130i, 130ii, and 130iii. Each segment 130 includes a corresponding coupling efficiency that is matched to provide uniform illumination of each transparent ring 126 along the length of the reference 103. Each segment 130 can include any number of transparent rings 128 and opaque rings 129.

[0154] In other embodiments, the light guide body 102 may include one, two, four, five, six, seven, eight, nine, ten, or more than ten segments 130. The number of segments 130 may be selected to provide adequate illumination.

[0155] In the illustrated embodiment, each segment 130 includes coupling efficiency to produce a uniformly illuminated annular image on the at least one imaging sensor 1116 .

[0156] Importantly, the light guide body 102 comprises a higher coupling efficiency than the coupling efficiency of the topographical illumination source 105 comprising the distributed illumination source 200 and the contour optics illumination source 201 radiating into free space.

[0157] like Figure 8A As shown, each light guide segment 130 and a portion or all of the outer surface 142 may include an optical isolation cover 131 to prevent light from leaking into other light guide segments and / or to prevent or reduce light from being coupled out of the light guide body 102 .

[0158] Segment 130(i) comprises a target segment that can be colored or otherwise include visible markings to provide a target for the gaze of the eye 106 looking through the central channel 124. In the illustrated embodiment, the target segment 130(i) is colored green, although not visible in the black and white illustration. The target segment 130(i) is shown disposed at the distal end of the light guide body 102. All other segments 130(i), (ii) can be of the same transparent material but differ from 130(i) in size and coupling efficiency, and are preferably clear.

[0159] Figure 2A FIG. 1 shows a component for corneal topography according to an embodiment of the present invention, and FIG. Figure 2B Components for contour imaging according to one embodiment of the present invention are shown. Figure 8A and 8B Further explanation is provided which shows the optical paths for the central topography optical system 150 and the contour system 172 respectively.

[0160] like Figure 2A and 2B As shown in both, by including a topographic illumination source 105 ( Figure 2A ) and contour optics illumination source 201 ( Figure 2B ) provides illumination for the topographer 100. The light guide body 102 is illuminated by the topographic illumination source 105. Significantly, the topographic illumination source 105 and the contour optics illumination source 201 are distinguishable. The topographic illumination source 105 and the contour optics illumination source 201 can emit light of sufficiently different wavelengths so that no interference with the image on the at least one imaging sensor 116 occurs.

[0161] The topographic illumination source 105 illuminates the reference object 103 or at least the transparent ring 128. That is, the topographic illumination source 105 illuminates the light guide body 102 to provide light for illuminating the cornea 107 and for projecting the reference object 103 onto the anterior corneal surface 148.

[0162] The topographic illumination source 105 includes a distributed illumination source 200 and thus includes a plurality of individual illumination sources in the form of topographic illumination LEDs 153 that emit polychromatic or white light. The plurality of LEDs 153 are included in two or more concentric rings of LEDs 153 that are included on a printed circuit board (PCB) 203. Although no corresponding figures are provided, in the illustrated embodiment, the topographic illumination source 105 includes an outer ring 105(a) and an inner ring 105(b).

[0163] Figure 8AThree optical paths of light emitted by a topographic illumination source 105 comprising LEDs 153 are shown. Some light follows an optical path, such as topographic optical path 206a, and is completely coupled out of the light guide body 102 from the outer surface 142. Other light partially follows a topographic optical path 206b, in which the light is partially coupled out of the light guide body 102 from the outer surface 142, and partially follows a topographic optical path 206c, in which the light is reflected from the outer surface 142 toward the inner surface 141 at the eye 106 before passing through the central channel 124 to be incident on the at least one imaging sensor 116. That is, light within the light guide body 102 may be split at the outer surface 142 and partially refracted and disposed to the surrounding environment. Light path 206d shows that light rays do not pass through outer surface 142 and pass toward inner surface 141 to be incident on eye 106 before passing through central channel 124 and central imaging system 123 to be incident on at least one imaging sensor 116 to form corneal image 204. That is, image strip 126 is imaged on imaging sensor 116.

[0164] Steering Figure 2B , shows a profile optics illumination source 201 comprising a profile point light source 202 in the form of a single LED emitting infrared light. Light from the point light source 202 passes through the light guide body 202 and is directed across the corneal profile 110 by the guiding optical system so as to be received by the reflective optical system 111 and directed to the profile imaging system 112 so as to be directed to the capture system 113 and at least one imaging sensor 116 that form and capture the profile image 205.

[0165] Directional optical system 108 is shown as including mirror 133, and reflective optical system 111 is shown as including prism 143. In other embodiments, the arrangement is reversed with directional optical system 108 including prisms and reflective optical system 111 including mirrors.

[0166] Profile imaging system 112 is shown to include mirrors 133 and other components that direct light propagation direction vector 134 to capture system 113 .

[0167] from Figure 2A and Figure 2B As can be seen, imaging is performed using a capture system 113, which is shown as including at least one imaging sensor 116. In other embodiments, the capture system 113 includes two or more imaging sensors, which may be provided in the form of a topographic imaging sensor 173 (not shown) and a contour imaging sensor 152 (not shown).

[0168] Figure 2AIt is also shown that the relative positions of the light guide body 201 and the eye 106 can be moved (such as using a positioner 167). This is advantageous because it allows the eye 106 to be conveniently positioned for each respective optical system 300a, 300b, 300c, 300d included in the interchangeable optical system 300. Figure 3A 、 Figure 3B 、 Figure 3C and Figure 3D In the embodiment shown in , the interchangeable optical systems 300 are arranged on a positioner 301 in the form of a wheel 302, which can be rotated in each direction to accurately align each corresponding optical system 300a, 300b, 300c, 300d in the central channel and with one or more capture systems 113.

[0169] like Figure 3A As shown, the wheel 302 includes a through-hole 308 for the axis of the central channel 144 of the central mapping system 150 .

[0170] The wheel 302 can rotate in either direction, clockwise or counterclockwise. Figure 3A As indicated by the arrow on the

[0171] The wheel 302 includes an indexing position 303 that engages one or more teeth. Figure 3A 、 Figure 3B 、 Figure 3C and Figure 3D One or more teeth 309 , which in the embodiment shown in FIG. 3 , comprise a single tooth, may be arranged on a pivot rod 305 that acts as a spring 304 .

[0172] Wheel 302 includes one or more indexing positions 303 for precise positioning of each of the two optical systems. Figure 3A 、 Figure 3B 、 Figure 3C and Figure 3D In the illustrated embodiment, the interchangeable optical system 300 includes four optical systems 300a, 300b, 300c, and 300d and four corresponding indexing positions 303a, 303b, 303c, and 303d. By selecting the appropriate indexing positions 303a, 303b, 303c, and 303d for engagement with one or more teeth 309, the corresponding optical systems 300a, 300b, 300c, and 300d can be accurately positioned relative to the central channel 124 for imaging the eye 106.

[0173] Figure 3A One or more teeth 309 are shown not engaged with the wheel 302 as it transitions between the two indexed positions 303 . Figure 3BWheel 302 is shown rotated further such that one or more teeth 309 are now engaged as wheel 302 and pivot rod 305 spring back into engagement with wheel 302 .

[0174] Figure 3D Another embodiment of a positioner 301 is shown that uses a sliding element 306 instead of a pivoting rod 305 .

[0175] Although not shown, the positioner 301 further includes one or more actuators 307 in the form of electric motors 421 for effecting rotation.

[0176] Figure 4 Another embodiment of the positioner 301 is shown, comprising a motor 421 that drives a drive belt 422 to effect rotation of the wheel 302. In another embodiment, the wheel 302 comprises a gear.

[0177] exist Figure 3D In the embodiment shown, the interchangeable optical system 300 includes six optical systems. In other embodiments, two, three, five, seven, eight, nine, ten, or more than ten optical systems may be included.

[0178] The positioner 301 is a backlash-free positioner that advantageously provides precise positioning and prevents or at least reduces undesired movement.

[0179] Advantageously, the light guide body 102 is illuminated in different colors depending on the light emitted by the illumination array 155. The light emitted by the illumination array 155 can include different distinguishable colors that indicate the modality in use, such as the central topographical mapping system 150, the contour system 172, or one of the corresponding interchangeable optical systems 300.

[0180] From the above, the skilled person will understand that the visible light portion of the light propagation for illumination of the eye 106 can be separated on its outer surface and coupled out of the light guide body 102 to the surrounding area and visible to the user or patient. In addition to other illumination means for imaging the eye 106 or for imaging the surrounding area of ​​the subject's eye 106, the coupled-out light can also be used to illuminate the eye 106.

[0181] The light coupled out and visible to the user or the tested subject may contain information about the operating state of the topographer 100 or additional information. The light information may be presented in the form of color as a preferred embodiment, but may also include other light modulations like light pulses or varying brightness.

[0182] The light guide body 102 also provides a portion of the light path propagation for illuminating the corneal profile 110 and imaging the corneal image 204 onto the at least one imaging sensor 116 .

[0183] Figure 7A A contour image 205 (left hand side) and a cornea image 204 (right hand side) are shown. Figure 7A Also advantageously shown, the profile data includes a profile outline 137 and a vertex position 138. A reference position 139 may be applied to determine the position of the eye 106 relative to the reference 130 or the central imaging system 123. These images 204, 205 can be reconstructed using data captured from one or more capture systems 113.

[0184] Figure 7B 、 Figure 7C 、 Figure 7D and Figure 7E Example information and images that may be obtained with interchangeable optical system 300 are shown. Figure 7B Shows the front image of the eye. Figure 7C An image of the cornea is shown. Figure 7D Showing contact lens wearing images, Figure 7E An image of the meibomian glands is shown. For example, Figure 7B 、 Figure 7C 、 Figure 7D and Figure 7E These can be obtained using optical systems 300a, 300b, 300c and 300d, respectively.

[0185] Another significant advantage of the interchangeable optical system 300 is that each optical system 300a, 300b, 300c, 300d, etc. is complete and does not require any other imaging components, either isolated or shared between each component interchangeable optical system 300a, 300b, 300c, 300d, etc., or generally from the topographer 100. This allows more than one imaging function to be performed.

[0186] Figure 5 A schematic diagram of a prior art apparatus for imaging corneal contour is shown. This cross-sectional view shows the prior art contour optics and the corresponding light path outside (or mostly outside) the light guide body.

[0187] This is consistent with the Figure 8B The contour system 172 and contour optical path 206 shown in FIG.

[0188] Figure 8BA contour optical path 206 is shown for light emitted by the contour optics illumination source 201. The light passes through the transparent medium 104 to the directional optical system 108 and the reflective optical system 111 mounted at opposite points on the proximal end 109 of the light guide body 102. The directional optical system 108 includes a mirror 143 that directs the transmitted light across the corneal contour 110 along the portion of the contour optical path 206 between the mirror 143 and the prism 143 included in the reflective optical system 111.

[0189] Reflective optical system 111 reflects the directed light from directional optical system 108 that has passed through corneal profile 110 and aims the directed light back through light guide body 102 to profile imaging system 112 and to one or more capture systems 113 .

[0190] At least a portion of the light captured by directional optical system 108 is incident on reflective optical system 111 disposed adjacent distal end 110 of cone 100. Profile image 206 includes information regarding the distance of subject's eye 190 from a reference point. The distance information is used in conjunction with information included in the corneal image to obtain corneal curvature information. The distance information is derived by measuring the profile outline 137 of profile image 205 and comparing its vertex position 138 to a reference position on profile image 205.

[0191] like Figure 2B As shown, the profile imaging system 112 also includes one or more focusing lenses 135 to focus the profile plane of the eye 106 onto the at least one imaging sensor 116. The profile imaging system 112 can be designed to correct for the optical path length through the light guide body 102.

[0192] Figure 2B The profile imaging system 112 is also shown to include a filter 254 that transmits only or substantially only infrared light from the profile optics illumination source 201 .

[0193] The surfaces on the light guide body 102 for light propagation for eye contour imaging are substantially perpendicular to the light propagation direction vector 134. That is, the guiding optical system and the reflective optical system reflect light substantially at right angles, and both propagation direction vectors intercept the axis of the central channel at right angles.

[0194] It may be desirable to provide additional light to the central mapping system 105 . Figure 6 A schematic cross-sectional view of the topographer 100 is shown, illustrating the relative position of the external illuminator 207 with respect to the light guide body.

[0195] The external illuminator 207 is out of the plane of the light guide body 102 and thus is positioned differently from the centrally or internally positioned illumination array 155 and the topographic mapping illumination source and the contour imaging illumination source 201 that are in the same plane as the light guide body 102 .

[0196] External illuminator 207 includes light source 208, which provides additional lighting, such as Figure 6 and Figure 9 In the illustrated embodiment, the light source 208 comprises an LED.

[0197] Steering Figure 10 、 Figure 11A and Figure 11B The topographer 100 may further include a sclera measurement device 400 . The sclera measurement device 400 includes one or more sclera projection systems 401 , each of which includes a sclera projection light source 406 and a sclera reference object 402 .

[0198] The scleral reference 402 includes at least one aperture 415 including one or more apertures 415a. The one or more apertures 415a are arranged in a scleral aperture pattern 405 and an optional corneal aperture pattern 414. When imaged on the eye 106 or at least one imaging sensor 116, the scleral aperture pattern 405 can be imaged as one or more scleral locators 418 and the corneal aperture pattern 414 can be imaged as a corneal scatter image 419. Figure 11A In

[0045] , the corneal scatter image 419 passes through the cornea, so the measurement is made in volume scattering through the eye.

[0199] The one or more scleral projection systems 401 also include a scleral projection imaging system 403, which is shown as including one or more lenses.

[0200] exist Figure 10 In the illustrated embodiment, the one or more scleral projection systems 401 include two symmetrically arranged scleral projection systems 401, one scleral projection system 401 mounted on each side of the topographer 100. The symmetrically mounted scleral projection systems 401 may include scleral projection systems 401 mounted on either side of the topographer 100. In one embodiment, the scleral projection systems 401 are arranged on either or both sides of the light guide body 102, i.e., a symmetrically mounted left scleral projection system 401 and a symmetrically mounted right scleral projection system 401. This allows the aperture patterns 405, 414 to be projected onto different portions of the surface of the eye.

[0201] The scleral aperture pattern 405 illuminated by the scleral projection light source 406 can be imaged onto the scleral projection imaging system 403 and the sclera portion of the eye surface. The corneal aperture pattern 414 illuminated by the projection light source 406 can also be imaged onto the projection imaging system 403 and the cornea 107.

[0202] The sclera measurement device 400 also includes one or more sclera registration reference projectors 404, which include a sclera reference light source 408 and a sclera registration reference 407. The sclera registration reference 407 may include a registration reference light guide 409, which may optionally be provided in the form of two or more concentric rings and may include a second Placido disk. Light from the sclera reference light source 408 and passing through the sclera registration reference 407 may be reflected from the surface of the eye and imaged by the imaging system 123 onto one or more image capture systems 113.

[0203] Light from the scleral reference light source 408 passes through the scleral registration reference 407 and reflects from the surface of the eye to form a scleral image 410, which is digitally processed to obtain corneal height information and scleral position and includes scleral height information. Readers familiar with corneal topography understand that the height information and curvature information of the eye 106 are conjugate and contain the same information. Scleral height information and scleral curvature information can be converted from one to the other by applying well-known mathematical methods.

[0204] The processed sclera image 410 can be used to combine the corneal height information from the topographer 100 with the sclera height information to form a new sclera topography map. This combination can include image registration. The registration can utilize one or more of the sclera locators 418, the corneal scatter image 419, and the sclera registration reference image 420.

[0205] The registration aperture 423 includes two or more adjacent registration apertures 423a through which light from the scleral reference light source 408 can propagate and be positioned on the cornea 107. In the illustrated embodiment, the two or more adjacent registration apertures 423a include corresponding groups of one or two or more adjacent transparent dots. In other embodiments, the adjacent registration apertures 423a include a group of one or two or more adjacent alternating transparent and opaque rings (concentric with the axis of the central channel 124) to form the second Placido disk 416. Figure 13 As shown, two or more adjacent registration apertures 423a include three transparent rings. In yet another embodiment, the rings can be used as reference apertures and can be used with alternating rings 418.

[0206] The projected scleral aperture pattern 405 and the registration stop 423 on the eye surface can be imaged together in the same image on one or more capture systems 113. From these two adjacent rings or dots of the registration stop 423, curvature information and height information of the reflecting eye surface can be derived.

[0207] The sclera measurement device 400 may also apply an algorithm to improve the accuracy of the sclera height information by comparing the eye reference axis of the sclera image 410 with the eye reference axis of the cornea image 204. The reference axis may include an axis from the eye 106 to the central channel 124 or rotational information between the eye 106 and the central channel 122.

[0208] In one embodiment, the light guide body and the topographic illumination source can form a corneal reference. In a preferred embodiment, the corneal reference includes a corneal reference for the vertex and a corneal aperture pattern for additional corneal reference information projected by the light guide body and the topographic illumination source.

[0209] Advantageously, the pupil 413 can be captured in both the sclera image 410 and the cornea image 204, wherein the captured pupil information can provide information of the reference axis of the eye. Additionally or alternatively, other uniquely identifiable sclera features can be used to combine corneal and sclera height information.

[0210] Additionally, the pupil center position of the eye 106 relative to the axis of the central channel 124 may be measured to provide reference data for combining corneal and scleral height information.

[0211] The use of the sclera measurement device 400 as part of the topographer 100 allows for combining sclera data with corneal topography data. Advantageously, this does not rely on a scattered image but rather uses a reflected image of the cornea. Additionally, the relative pupil position of the two eyes can be measured to provide reference data for image registration.

[0212] One advantage of the present invention is that the diameter at the proximal end 113 can be reduced because the illumination is no longer outside of the light guide body 102. This allows the corneal surface 148 to be closer to the light guide body 102 and therefore allows a larger portion of the cornea to be analyzed.

[0213] Another advantage of the present invention is that the lighting no longer causes shadows that affect the light distribution. The present invention also greatly reduces the number of parts required for the lighting and the complexity of its manufacture.

[0214] In this specification, the terms “comprises,” “comprising,” or similar terms are intended to represent a non-exclusive inclusion, such that a device that includes a list of elements includes not only those elements but may also include other elements that are not listed.

[0215] Throughout the specification, the purpose is to describe the present invention without limiting the present invention to any one embodiment or specific feature set. Those skilled in the relevant art may implement variations from the specific embodiments, but still fall within the scope of the present invention.

Claims

1. An ophthalmic topographer, comprising: Corneal topographer; a sclera measurement device comprising one or more sclera projection systems; as well as A scleral registration reference projector, wherein the scleral registration reference projector includes a scleral reference light source and a scleral registration reference, and wherein light from the scleral reference light source passes through the scleral registration reference and reflects from the surface of the eye to form at least a portion of a scleral image.

2. The ophthalmic topographer of claim 1 , wherein the corneal topographer directs a reference onto the surface of the eye, and wherein The guided reference object includes a projected reference object or an image strip.

3. The ophthalmic topographer of claim 1 , further comprising a topographic illumination source.

4. The ophthalmic topographer of claim 2, further comprising an imaging system that images the reference object directed onto the surface of the eye through a central channel in the topographer body.

5. The ophthalmic topographer of claim 1 , wherein each of the one or more scleral projection systems comprises a scleral projection light source and a scleral reference, and wherein, The scleral reference may include at least one stop including two or more apertures through which light may propagate and be disposed on the cornea.

6. The ophthalmic topographer of claim 5, wherein the one or more apertures comprise a scleral aperture pattern, a corneal aperture pattern, or both a scleral aperture pattern and a corneal aperture pattern.

7. The ophthalmic topographer according to claim 6, wherein: When imaged on the eye or an imaging sensor, the scleral aperture pattern is imaged as one or more scleral locators and / or the corneal aperture pattern is imaged as a corneal scatter image.

8. The ophthalmic topographer according to claim 6, wherein: The scleral aperture pattern illuminated by the scleral projection light source is imaged onto the projection imaging system and onto the scleral portion of the eye surface, and / or wherein the corneal aperture pattern illuminated by the projection light source is imaged onto the projection imaging system and onto the cornea.

9. The ophthalmic topographer according to claim 1, wherein: The one or more scleral projection systems are symmetrically mounted on the topographer.

10. The ophthalmic topographer according to claim 1, wherein The scleral registration reference projector includes a registration reference light guide.

11. An ophthalmic topographer, comprising: Corneal topographer; a sclera measurement device comprising one or more sclera projection systems; as well as A processor combines the sclera height information obtained from the sclera measurement device with the corneal height information obtained from the corneal topographer.

12. The ophthalmic topographer of claim 11, wherein the corneal topographer directs a reference onto the surface of the eye, and wherein The guided reference object includes a projected reference object or an image strip.

13. The ophthalmic topographer of claim 11, further comprising a topographic illumination source.

14. The ophthalmic topographer of claim 12, further comprising an imaging system that images the reference object directed onto the surface of the eye through a central channel in the topographer body.

15. The ophthalmic topographer of claim 11, wherein each of the one or more scleral projection systems comprises a scleral projection light source and a scleral reference, and wherein, The scleral reference may include at least one stop including two or more apertures through which light may propagate and be disposed on the cornea.

16. The ophthalmic topographer of claim 15, wherein the one or more apertures comprise a scleral aperture pattern, a corneal aperture pattern, or both a scleral aperture pattern and a corneal aperture pattern.

17. The ophthalmic topographer according to claim 16, wherein When imaged on the eye or an imaging sensor, the scleral aperture pattern is imaged as one or more scleral locators and / or the corneal aperture pattern is imaged as a corneal scatter image.

18. The ophthalmic topographer of claim 16, wherein: The scleral aperture pattern illuminated by the scleral projection light source is imaged onto the projection imaging system and onto the scleral portion of the eye surface, and / or wherein the corneal aperture pattern illuminated by the projection light source is imaged onto the projection imaging system and onto the cornea.

19. The ophthalmic topographer according to claim 11, wherein The one or more scleral projection systems are symmetrically mounted on the topographer.

20. The ophthalmic topographer of claim 11, further comprising a scleral registration reference projector and a registration reference light guide.

21. An ophthalmic topographer, comprising: Corneal topographer; A sclera measurement device comprising one or more sclera projection systems; wherein the sclera measurement device applies an algorithm to improve the accuracy of sclera height information by comparing an eye reference axis of a sclera image with an eye reference axis of a corneal image.

22. The ophthalmic topographer of claim 21, wherein the corneal topographer directs a reference onto the surface of the eye, and wherein The guided reference object includes a projected reference object or an image strip.

23. The ophthalmic topographer of claim 21, further comprising a topographic illumination source.

24. The ophthalmic topographer of claim 22, further comprising an imaging system that images the reference object directed onto the surface of the eye through a central channel in the topographer body.

25. The ophthalmic topographer of claim 21 , wherein each of the one or more scleral projection systems comprises a scleral projection light source and a scleral reference, and wherein, The scleral reference may include at least one stop including two or more apertures through which light may propagate and be disposed on the cornea.

26. The ophthalmic topographer of claim 25, wherein the one or more apertures comprise a scleral aperture pattern, a corneal aperture pattern, or both a scleral aperture pattern and a corneal aperture pattern.

27. The ophthalmic topographer of claim 26, wherein: When imaged on the eye or an imaging sensor, the scleral aperture pattern is imaged as one or more scleral locators and / or the corneal aperture pattern is imaged as a corneal scatter image.

28. The ophthalmic topographer of claim 26, wherein: The scleral aperture pattern illuminated by the scleral projection light source is imaged onto the projection imaging system and onto the scleral portion of the eye surface, and / or wherein the corneal aperture pattern illuminated by the projection light source is imaged onto the projection imaging system and onto the cornea.

29. The ophthalmic topographer of claim 21, wherein The one or more scleral projection systems are symmetrically mounted on the topographer.

30. The ophthalmic topographer of claim 21 further comprising a scleral registration reference projector and a registration reference light guide.

Images