Ophthalmic imaging method, apparatus and system

Abstract

A light guide for an ophthalmic topographer is disclosed. The light guide includes: a light guide body, a topographic illumination source, a directional optical system, and a reflective optical system. The light guide body includes a reference object; the topographic illumination source illuminates the light guide body and the reference object, wherein the illuminated light guide body guides light for illuminating the eye; the directional optical system is accommodated in the proximal end of the light guide body and guides the light from the light guide body across the corneal contour; the reflective optical system is accommodated in the proximal end of the light guide body and reflects the light that has passed through the light guide body across the corneal contour from the directional optical system. An ophthalmic topographer including the light guide is also disclosed. An ophthalmic topographer including the scleral projection system is further disclosed. A method for determining a topographic map is also disclosed.

Description

Technical Field

[0001] 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 including a multi-functional light guide and a scleral measurement system. Background Art

[0002] A corneal topographer measures the geometry of the anterior corneal surface by capturing a reflected image of the cornea from a known illumination target pattern, imaging one or more mires on the eye, typically a series of concentric illumination rings separated by black opaque annuli known as a Placido system, and analyzing these mires starting from a known position at the apex of the cornea. A separate system is required to determine the distance from a known reference position of the imaging system to the apex of the cornea.

[0003] Known corneal topographers direct light through the corneal profile and form an image of the profile on an imaging sensor via one or more mirror and lens systems. Such a profile imaging system allows the position of the corneal vertex to be measured while acquiring an image of the target reflection.

[0004] Scheimpflug topography and other projection-based topography systems as well as more recent OCTs (Optical Coherence Tomography) have been applied to corneal and scleral mapping. Using the Scheimpflug method, high-intensity light for the retina typically causes the sclera to become blurred. Other drawbacks of Scheimpflug systems are the high cost of the instrument and the long capture time, which results in a loss of precision and thus requires complex registration methods. By referencing both through the limbus, the application of low-intensity light to the sclera and high-intensity light to the retina has been investigated. Projection systems and OCTs may lack accuracy in the important central corneal region and are not economical for many users in the field.

[0005] There is a need for alternative and improved corneal topographers and devices for mapping the cornea and sclera and effectively adding additional diagnostic features to the topographer to meet the growing demands of the market.

[0006] Any reference to any prior art in this specification is not and should not be taken as an admission or suggestion in any form that the prior art constitutes a part of common general knowledge. Summary of the Invention

[0007] The present invention relates to an ophthalmic imaging method, apparatus, and system.

[0008] In one broad form, the present invention is directed to an ophthalmic imaging method, apparatus, and system including a multi-functional light guide.

[0009] In another broad form, the present invention relates to an ophthalmic topographic light guide for illuminating the eye. In yet another broad form, the present invention relates to an ophthalmic topographic light guide or cone that illuminates the eye and transmits light for capture.

[0010] 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:

[0011] a light guide body that includes a reference object; and

[0012] 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.

[0013] The illuminated light guide body according to the first aspect may also direct the reference object onto the eye surface. The oriented reference object on the eye surface may include a projected reference object or an image strip.

[0014] The light guide of the first aspect may further comprise:

[0015] an orientation optical system that is housed in the proximal end of the light guide body and directs light from the light guide body across the corneal contour; and

[0016] a reflective optical system that is housed in the proximal end of the light guide body and reflects light from the orientation optical system that has passed through the corneal contour via the light guide body.

[0017] The reflective optical system may direct the light to one or more capture systems that include 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.

[0018] In a second aspect, the present invention provides an ophthalmic topographer comprising:

[0019] a light guide body that includes a reference object;

[0020] 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

[0021] an imaging system that images the reference object projected onto the eye surface through a central channel in the light guide body.

[0022] In a third aspect, the present invention provides an ophthalmic topographer comprising:

[0023] a light guide body that includes a reference object;

[0024] A topographic map illumination source that illuminates a light guide body and a reference object, wherein the illuminated light guide body guides light for illuminating the eye;

[0025] An imaging system that images a reference object projected onto the surface of the eye through a central channel in the light guide body;

[0026] An orientation optical system that is housed in the proximal end of the light guide body and guides light from the light guide body across the corneal contour; and

[0027] A reflection optical system that is housed in the proximal end of the light guide body and reflects light from the orientation optical system that has passed through the corneal contour through the light guide body.

[0028] The imaging system according to any one of the above aspects may include one or more lenses. The imaging system may guide light onto one or more capture systems.

[0029] The reflection optical system according to any one of the above embodiments may reflect light for capture on at least one imaging sensor.

[0030] In a fourth aspect, the present invention relates to a light guide for an ophthalmic topographer, the light guide comprising:

[0031] A light guide body containing a reference object, wherein the light guide body guides light towards the reference object.

[0032] The light guide according to the fourth aspect may further include a topographic map illumination source that illuminates the light guide body and the reference object, wherein the illuminated light guide body guides light for illuminating the eye.

[0033] The light guide body according to any one of the above aspects may further include a substantially symmetric shape portion and / or include a corrugated contour portion at the proximal end. The corrugated contour portion may include symmetric and opposing extensions and recesses to obtain close proximity of the eye to the reference object and thus obtain large eye coverage. The extensions may house the orientation optical system and the reflection optical system. The extensions and / or recesses may be arranged at opposing points at the proximal end of the light guide body. The extensions and / or recesses may include fan-shaped edge portions.

[0034] According to any one of the above aspects, at least a portion of the orientation optical system and at least a portion of the reflection optical system may be arranged on opposite sides of the light guide body. In one embodiment, the orientation optical system is arranged on the left hand side relative to the operator, and the reflection optical system is arranged on the right hand side relative to the operator. In other embodiments, the orientation optical system is arranged on the right hand side, top or bottom relative to the operator, and the reflection optical system is arranged on the left hand side, bottom or top relative to the operator.

[0035] According to any of the above aspects, the directional optical system and the reflective optical system reflect light substantially at a right angle, and the two propagation direction vectors intercept the axis of the central channel at a right angle.

[0036] According to any 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.

[0037] 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) 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 a topographic map of the eye using a reference object. The contour capture system may be used in an eye contour analysis using light guided by the reflective optical system. In another embodiment, the one or more capture systems include at least one imaging sensor for topographic map and eye contour analysis.

[0038] The ophthalmic topographer according to any of the above aspects may further include:

[0039] One or more optical systems for imaging the eye.

[0040] One or more optical systems may be arranged in the optical path to image the eye.

[0041] In an embodiment, when the one or more optical systems include two or more optical systems, the topographer may further include a locator for selectively positioning each of the optical systems included in the two or more optical systems in the optical path. Each of the two or more optical systems may include an interchangeable optical system in the optical path for imaging the eye.

[0042] The locator may include a wheel, and each of the two or more interchangeable optical systems may be located on the wheel. The wheel may include one or more indexing positions for precise positioning of each of the two or more optical systems. The locator may include a backlash-free locator. The locator may include one or more teeth. The wheel may include gears. The locator may include one or more actuators, such as an electric motor, etc.

[0043] The wheel may include one or more perforations for the central topographic map system.

[0044] In one embodiment of any of the above aspects, the topographer includes an illumination array that includes a topographic illumination source and a contour optics illumination source. The topographic illumination source may include a distributed light source. The distributed light source and the contour optics illumination source may be resolvable or distinguishable. The distributed light source and the contour optics illumination source may emit light at sufficiently different wavelengths so as not to interfere in their respective imaging paths.

[0045] 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, blue (RGB) LED. Each RGB LED may include a separate narrow band. Each of the plurality of LEDs may produce white light. The plurality of LEDs may include an array that is arranged as two or more LED rings in a particular embodiment. The two or more LED rings may be included on a printed circuit board.

[0046] 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.

[0047] 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 eye surface.

[0048] The topographic illumination source and / or the contour optics illumination source may be disposed at a distal end of the light guide body.

[0049] In one embodiment of any of the above aspects, the reference object includes a plurality of rings. The reference object may include a Placido disk that includes a plurality of concentric rings. The plurality of concentric rings may include alternating transparent rings and opaque rings. The transparent rings may be illuminated. The transparent rings may be integrated 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 object may include a cover layer that includes opaque rings. The opaque rings may be arranged to be linearly separated by transparent segments. The reference object may be sprayed or otherwise disposed on the light guide body. The spraying or other application may include applying only the opaque rings.

[0050] In another embodiment of any of the above aspects, the light guide body may include a plurality of sections, each section including a respective transmission coefficient. The selectable transmission coefficients provide uniform illumination along the length of the reference object. Each section may include any number of transparent and opaque rings. Each light guide section may include an optically isolating outer surface or cover. In one embodiment, a section may be colored to provide a visual target. In another embodiment, a section or the light guide body includes a color filter that provides a visual target. The colored section or color filter may be green. The color filter may include a polymer film in the optical path. The visual target or target section may be disposed at the distal end of the light guide body. The visual target or target section may transmit colored light. The light guide body may include two, three, four, five, six, seven, eight, nine, or ten sections. In one embodiment, the light guide body includes three sections. The number of sections may be selected to provide sufficient illumination.

[0051] 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 that of air for light propagation.

[0052] In another embodiment of any of the above aspects, the light guide body includes a substantially conical or toroidal shaped portion. The substantially conical shaped portion may include a frustoconical shaped portion. The conical or toroidal shaped portion may include an internal channel. The outer surface may include a curved or toroidal shaped portion, and the internal channel may include a substantially conical shaped portion.

[0053] In yet another embodiment of any of the above aspects, depending on the light emitted by the illumination array, the light guide body is illuminated in a selective color. The light emitted by the illumination array may include white light, red light, green light, blue light, or infrared light. The visual indication of the mode may include light pulses or different brightness or intensities for the selected color. The frequency, modulation, or duration of the light pulses may be varied. The brightness or intensity may vary with the mode.

[0054] In yet another embodiment of any of the above aspects, the directional optical system and the reflective system are positioned at substantially opposite points on the light guide body.

[0055] The directional optical system may include one or more prisms disposed between the light source and the exposed eye. The prism may include a diffusing prism.

[0056] The reflective optical system may include one or more mirrors.

[0057] In another embodiment, the directional optical system may include a mirror and the reflective optical system may include a prism.

[0058] 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).

[0059] In yet another embodiment of any of the above aspects, light from the reflection optical system as the target is incident on a contour imaging system disposed at the distal end of the light guide body.

[0060] In another embodiment of any of the above aspects, the contour imaging system includes one or more of a focusing lens system and a filter that transmits only light from the illumination source of the contour optics.

[0061] In yet another embodiment of any of the above aspects, the contour imaging system focuses the target light onto one or more capture systems. The focused target light includes information about the distance of the subject's eye from a reference point.

[0062] In yet another embodiment of any of the above aspects, the contour imaging system focuses the contour plane of the eye onto one or more capture systems.

[0063] The inner and outer surfaces of the light guide body can be polished. The polishing can achieve a desired reflection compared to the remaining scattering of the light propagating from the light source.

[0064] In yet another embodiment of any of the above aspects, a portion of the contour optical path is contained within the light guide body. The contour optical path and the internal contour optical path may include a directional optical system and a reflection optical system. The directional optical system guides the light across the eye contour to the reflection optical system. The reflection optical system guides the light to the focusing optical system and / or one or more capture systems.

[0065] In another embodiment of any of the above aspects, light from the topography 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 the following: light rays that are fully coupled out of the light guide body; light rays that are partially coupled out of the light guide body and partially incident on the eye; and light rays that are fully incident on the eye. In embodiments where the outer surface of the light guide body is sprayed or otherwise coated, the light rays that are fully coupled out of the light guide body may be absent. The light rays incident on the eye can then pass through the central channel and be incident on one or more capture systems.

[0066] According to any of the above embodiments, a reflection optical system and a directional optical system for imaging the eye contour are included in the contour system.

[0067] In another embodiment of any of the above aspects, the light guide body includes a reference object; a contour system; and the light guide body provides the necessary optical input to image the topography of the corneal surface.

[0068] In yet another embodiment of any of the above aspects, the light guide body includes at least a portion of a central topography system, the central topography system including: a light guide body; a topography illumination source; a reference object; and a topography imaging system. The central topography system may also be one or more capture systems.

[0069] According to any of the above embodiments, an ophthalmic topographer may include a corneal topographer. According to this embodiment, the eye surface includes the corneal surface; the eye contour includes the corneal contour; the illumination of the eye may include the illumination of the cornea; and the eye coverage may include corneal coverage.

[0070] According to any of the above aspects, the topographer may further include a scleral measurement device. The scleral measurement device may include one or more scleral projection systems. Each of the one or more scleral projection systems may include a scleral projection light source and a scleral reference object.

[0071] Each scleral reference object may include at least one diaphragm, the at least one diaphragm including one or more apertures. The one or more apertures may be arranged in an aperture pattern. The one or more apertures may 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 may be imaged as one or more scleral locators, and the corneal aperture pattern may be imaged as a corneal scatter image.

[0072] 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.

[0073] One or more scleral projection systems may be symmetrically mounted on the topographer. The symmetrically mounted scleral projection systems may include scleral projection systems mounted on either side of the topographer. In one embodiment, the scleral projection systems are arranged on either one 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 parts of the eye surface.

[0074] The scleral aperture pattern illuminated by the scleral projection light source may be imaged onto the projection imaging system and onto the scleral portion of the eye surface. The corneal aperture pattern illuminated by the projection light source may also be imaged onto the projection imaging system and onto the cornea.

[0075] The scleral measurement device may further include one or more scleral registration reference projectors. The scleral registration reference projector may include a scleral reference light source and a scleral registration reference. The scleral 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.

[0076] The light from the scleral reference light source and passing through the scleral registration reference may be reflected from the eye surface and imaged onto one or more image capture systems by the imaging system.

[0077] The light from the scleral reference light source, passing through the scleral registration reference and reflected from the eye surface, may form a scleral image. The scleral image may be digitized to obtain corneal height information and scleral position, and the scleral image may include scleral height information.

[0078] The processed scleral image may be used to combine the corneal height information from the topographer with the scleral height information into a new scleral topogram. The combination may include image registration. The registration may utilize one or more of a scleral locator, a corneal scatter image, and a scleral registration reference image.

[0079] At least one diaphragm may include two or more adjacent registration apertures, and the light from the scleral reference light source may pass through the registration apertures and propagate and be disposed on the cornea. In one embodiment, two or more adjacent registration apertures include corresponding groups of one or two or more adjacent transparent dots. In another embodiment, the adjacent registration apertures include a set of one or two or more adjacent transparent and opaque alternating rings concentric with the axis of the central channel, thereby forming a second Placido disk. In a particular embodiment, two or more adjacent apertures include three transparent circular rings. In yet another embodiment, the three transparent circular rings may be used as a reference diaphragm and may be used together with alternating transparent and opaque rings.

[0080] The projected scleral aperture pattern and the registration diaphragm on the eye surface may be imaged together on the same image onto one or more capture systems. From these two adjacent locators or dot-shaped members of the registration diaphragm, the curvature and height information of the reflected eye surface may be derived.

[0081] One or more scleral reference apertures and / or scleral registration apertures may be imaged by the imaging system onto the one or more imaging sensors.

[0082] The scleral measurement device may further apply an algorithm to improve the accuracy of the scleral height information by comparing the eye reference axis of the scleral image with the eye reference axis of the corneal image. The reference axis may include rotational information of the eye relative to the axis of the central channel or between the eye and the central channel.

[0083] In one embodiment, the light guide body and the topographic illumination source may form a corneal reference. In a preferred embodiment, the corneal reference includes a corneal reference projected by the light guide body, a topographic illumination source for the apex, and a corneal aperture pattern for additional corneal reference information.

[0084] In yet another embodiment, the pupil may be captured in both the scleral image and the corneal image, wherein the captured pupil information may provide information on the eye reference axis for additional corneal reference information.

[0085] In yet another embodiment, other uniquely identifiable scleral features may be used to combine corneal and scleral height information.

[0086] In another embodiment, the pupil center position of the eye relative to the axis of the central channel may be measured to provide reference data for combining corneal and scleral height information.

[0087] In a fifth aspect, the present invention provides a method for determining an ophthalmic topography, the method comprising:

[0088] Illuminating a light guide body containing a reference to project the reference onto the anterior surface of the cornea, wherein the illuminated light guide body projects light for illuminating the cornea;

[0089] Using a directional optical system housed in the proximal end of the light guide body to direct light from the light guide body through the corneal profile;

[0090] Utilizing a reflective optical system housed in the proximal end of the light guide body to reflect light that has passed through the corneal profile from the directional optical system through the light guide body;

[0091] Capturing the reflected light on at least one imaging sensor external to the light guide body; and

[0092] Capturing the reference projected onto the corneal surface through the central channel in the light guide body to determine the corneal topography.

[0093] The method of the fifth aspect may further comprise:

[0094] Imaging an aperture pattern projected onto the eye surface by one or more projection lens systems, wherein the aperture pattern projects at least one scleral reference and at least one corneal reference; and

[0095] Combining the scleral height information into the determined corneal height information.

[0096] According to any of the above aspects, the light guide may include a multi-functional light guide. The multi-function may include an imaging function and a contour optical function. The imaging function includes arranging light onto the eye for imaging the eye, and the contour optical function includes contour imaging of the outer shape of the eye. The multi-function and the imaging function may further include a topographic optical function, which includes imaging the topography of the eye.

[0097] According to any of the above aspects, the light guide may include a topographic cone.

[0098] According to any of the above aspects, the topographer includes one or more of a housing and a base plate. The topographer may further include a subject support, which includes one or more of a chin rest and a forehead rest. The topographer may further include an adjustment arm to move the chin rest up and down. The subject support may further include a calibration device attachment, to which a calibration device may be attached for calibrating the topographer. The topographer may further include a manually operated locator, such as a joystick. The manually operated locator may move the base unit in two axes: it may move laterally and forward and backward. The topographer may also move vertically, such as by rotation of the joystick. The vertical movement may be through a mounting post, on which the light guide and other components (such as a topographic illumination source, a contour imaging system, and a topographic imaging system) are mounted.

[0099] According to any of the above aspects, the topographer may be connected to a junction box via a topographer cable. The junction box may be connected to a computer via a computer cable and to a power supply.

[0100] According to any of the above aspects, the topographer may further include 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.

[0101] According to any of the above aspects, the topographer may further include an external illuminator. The external illuminator may provide light for an interchangeable optical system. The external illuminator may include symmetrically mounted light sources. The symmetrically mounted light sources may be arranged on both sides of the light guide, namely a symmetrically mounted left light source and a symmetrically mounted right light source. The light sources may be any suitable light sources, such as LEDs.

[0102] The housing may be a protective enclosure for one or more of a plurality of components including the base unit, the vertical mounting post, at least a portion of the light guide body, the external illumination device, and the scleral measurement device.

[0103] Other aspects and / or features of the present invention will become apparent from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0104] For the purpose of facilitating the understanding and implementation of the present invention, embodiments of the present invention will now be described with reference to the accompanying drawings, in which like reference numerals refer to like elements. The drawings are provided by way of example only, and in the drawings:

[0105] 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 perspective view of the topographer, and Figure 1B shows a close-up view of the cone and the cone housing.

[0106] Figure 2A and Figure 2B is a schematic diagram showing a cross-sectional view of an embodiment of the topographer of the present invention.

[0107] Figure 3A 、 Figure 3B 、 Figure 3C and Figure 3D is a schematic diagram showing an embodiment of a locator for positioning a lens system.

[0108] Figure 4 is a schematic diagram showing a locator according to another embodiment of the present invention.

[0109] Figure 5 is a schematic diagram showing a cross-sectional view and an optical path of a prior art device for obtaining corneal contour data.

[0110] Figure 6 is a schematic diagram showing another cross-sectional view and an optical path for obtaining scleral data according to an embodiment of the present invention.

[0111] Figure 7A 、 Figure 7B 、 Figure 7C and Figure 7D is a diagram showing: an embodiment of a contour image (left) and an embodiment of a corneal image (right)( Figure 7A ); a representation of an eye showing a reference object image( Figure 7B ); a representation of an eye photographed with illumination provided by an external illuminator( Figure 7C ); a representation of an eye wearing a contact lens and visualized with fluorescein( Figure 7D ; and a representation of an eye showing the meibomian glands( Figure 7E ).

[0112] Figure 8A and Figure 8B is a schematic diagram showing a cross-sectional view illustrating a corneal topography optical path( Figure 8A ) and a corneal contour optical path( Figure 8B ) according to an embodiment of the present invention.

[0113] Figure 9 is a schematic view showing a cross-sectional view of a corneal topographer and a corneal contour optical path with additional external illumination according to an embodiment of the present invention.

[0114] Figure 10 is another schematic view showing a cross-sectional view of a corneal and scleral topographer optical path according to an embodiment of the present invention.

[0115] Figure 11A and Figure 11B is a schematic view showing an optical path for image registration according to an embodiment of the present invention.

[0116] Figure 12A and Figure 12B is a schematic view showing an orientation reference for image registration according to an embodiment of the present invention.

[0117] Figure 13 is a schematic view showing a front view of a topographer according to an embodiment of the present invention.

[0118] Figure 14A and Figure 14B shows a commercial embodiment of an optical waveguide and a topographer according to the present invention.

[0119] Those skilled in the art should understand 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 the understanding of the embodiments of the present invention. Detailed Description

[0120] Embodiments of the present invention relate to an improved ophthalmic topographer optical waveguide and an improved ophthalmic topographer. Those skilled in the art will readily understand that an optical waveguide for topography is also referred to as a "cone". This is because such optical waveguides are typically conical. The optical waveguide of the present invention has a substantially conical inner surface; however, the outer surface is not conical. Given the convention and the terminology used in the art, these terms, optical waveguide and cone, may be used interchangeably herein.

[0121] The inventors have unexpectedly found that by integrally including a reference in the illuminating corneal topographer optical waveguide, the reference can form part of the optical waveguide body and the imaging system. This has significant advantages because the optical waveguide body can be smaller, and the optical waveguide function can be provided by the optical waveguide body, which is more cost-effective and allows additional imaging modes and improved corneal topography performance. Another advantage of an embodiment of the present invention is that contour optics can be provided in the optical waveguide body.

[0122] In another embodiment, the present invention provides a multi-functional topographic map by providing a gapless interchangeable lens system. The ability to use a single lens for each interchangeable system optical system means that more control can be exercised over each lens design and overall quality can be improved.

[0123] Additionally, an ophthalmic topographer provides scleral topographic mapping capabilities and methods for the first time. This is accomplished while maintaining high-quality corneal topography and the additional data of scleral topography can be combined therewith. This can result in better quality and improved contact lens fitting. Moreover, no fluorescein is required to obtain topographic information of the cornea or sclera, which is a great advantage for the user and beneficial to subject comfort when compared with the prior art.

[0124] As used herein, "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, in the case where a particular optical system is described herein as including one or more prisms, it should be understood that different configurations including one or more lenses or other imaging components, mirrors, prisms, spectral filters, and / or apertures may substitute for the prisms.

[0125] As used herein, "imaging system" means a particular type of optical system that forms a real or virtual image of an object.

[0126] As used herein, "mire" is a pattern of reference objects, the image of which, as reflected by the curved surface of the cornea, is used to calculate the topographic map of the cornea.

[0127] It will become apparent from the following description that the light guide or cone of the present invention is a multi-functional light guide or cone. As used herein, "multi-functional light guide or cone" is used to refer to a light guide or cone that performs more than one optical function. In one embodiment, the multi-functional light guide body directs light and mires onto the eye for imaging the mires imaged on the eye onto an imaging sensor and further includes a contour optical system for imaging the contour of the eye.

[0128] Generally, one embodiment of the present invention relates to a conical body or light guide body that includes a reference object for a topographer.

[0129] In another embodiment, the present invention relates to an optical waveguide or cone that includes 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 an imaging sensor.

[0130] As will be described hereinafter, in one embodiment, the present invention also provides an interchangeable optical system to allow for the performance of more than one operating modality and imaging function.

[0131] An embodiment of the topographer 100 according to the present invention is shown in FIG. 1. The topographer 100 includes a topographic optical waveguide or cone 101 housed in a housing 121. A base plate 120 provides a stable support. A stable platform is provided by a subject support 122 that 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 such that the height of the eye 106 is aligned with the optical axis of the topographer 100.

[0132] 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) inserted into a USB (Universal Serial Bus) port, and is connected to a power supply 163 (not shown) via a power cable 164 (not shown).

[0133] 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 calibrating the topographer 100.

[0134] The topographer 100 also includes a manually operated locator 167 that includes a joystick 168 that can be used to move the base unit 169 in two axes, laterally and longitudinally. Additionally, vertical movement is achieved by rotation of the joystick 168. This allows for accurate and convenient alignment of the topographer 100 with the subject's eye 106. The vertical movement is effected through a mounting post 169 on which the optical waveguide 101 and other components (such as an optical waveguide illumination array 155, a contour imaging system 112, and a topographic imaging system 123) are mounted.

[0135] As will be described in further detail hereinafter, the topographer 100 also includes an external illuminator 207 that provides additional light for topography and for additional ophthalmic imaging functions. The external illuminator 207 includes light sources 208 symmetrically mounted on either side of the optical waveguide 101. The light sources 208 can be any suitable light source, such as an LED.

[0136] The following further description is of an optional manner of the scleral measurement device 400 included in some embodiments of the topographer 100. The scleral measurement device 400 includes Figure 10 and Figure 11A one or more scleral projection systems 401 and scleral reference objects 402 as shown in. The scleral measurement device may further include one or more scleral registration reference object projectors 404.

[0137] Also as described in further detail below, the imaging system 123 also includes one or more actuators 307 (not shown), such as electric motors, that rotate the wheel 302 to a defined position for alignment in the imaging system optical path.

[0138] 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. As Figure 1A and Figure 1B shown, all internal components are enclosed in a housing 121 that forms a protective enclosure around the base unit 169 and the vertical mounting post 170. Additionally, the light guide body 102 is partially enclosed within the housing 121.

[0139] Figure 1B A portion of the light guide 100 and the contour imaging system 112 is shown. The light guide 100 includes a light guide body 102 that includes at least a portion of a reference object 103 that is illuminated to image a topographic ring or annulus as an image strip 126.

[0140] The light guide body 102 includes a transparent medium 104. In the embodiment shown in FIG. 2, the transparent medium 104 includes poly(methyl methacrylate) (PMMA). Based on the teachings herein, one skilled in the art can readily select any other suitable transparent medium. The transparent medium 104 may include one or more optically uniform and transparent media.

[0141] The light guide body 102 includes a shaped portion of a substantially toric or conical outer surface 142 and a shaped portion of a substantially conical inner surface 141. In the embodiment shown in the drawings, the substantially toric or conical shaped portion is a toroidal or frustoconical shaped portion 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 diameter is greater than the proximal diameter such that concentric transparent rings 128 and opaque rings along the length of the light guide body 102 decrease in circumference from the distal end 115 to the proximal end 109.

[0142] The light guide body 102 is conveniently sized to fit the shape of a human face, wherein the aperture diameter of the central channel is less than 35 mm, and 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.

[0143] In another embodiment, the light guide body 102 is substantially symmetric and includes a corrugated profile portion 125 (not shown) at the proximal end 109. The corrugated profile portion 125 includes symmetric and opposing extensions 145 (not shown) and recesses 146 (not shown). The extensions 145 house at least a portion of the collimating optical system 108 and at least a portion of the reflecting optical system 111. The extensions 145 are arranged at opposing points of the proximal end 109. The recesses 146 are also arranged at opposing points of the proximal end 109. The extensions and recesses may include fan-shaped edge portions.

[0144] In another embodiment of any of the above aspects, at least a portion of the collimating optical system and at least a portion of the reflecting optical system are positioned opposite each other on the proximal end of the light guide body. Apparently, the collimating optical system directs light at right angles to the optical axis.

[0145] The light guide 101 is attached to the topographer 100 by a mounting flange 147 (not shown). The toric or conical shaped portion of the light guide body 102 that houses the central channel 124 allows the eye 106 to be exposed to the reference object 130 disposed on the inner surface 141.

[0146] Figure 1B A 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 through which the reference object 103 is visible through the central channel 124.

[0147] As Figure 1B shown in the perspective view and Figure 2A the cross-sectional view of, the reference object 130 includes a plurality of rings or annular members in the form of alternating transparent rings 128 and opaque rings 129 (shown as dashed lines in the Figure 2A cross-sectional view). In the illustrated embodiment, the reference object 130 includes a plurality of transparent rings 128, each transparent ring 128 being adjacent to opaque rings 129 on both sides and disposed on the inner surface 141 along its axial length. The terminal transparent ring 128 and opaque ring 129 will only be adjacent to the opaque ring 129 and transparent ring 128 on the non-terminal side.

[0148] When the light guide 101 is illuminated, a plurality of transparent rings 128 are illuminated and form a virtual image of concentric rings, such as image strips 126 produced by the curvature of the anterior corneal surface 148. By imaging and analyzing the imaging concentric annular image strips 126 produced by the anterior corneal surface 148 through the imaging system 123 by the transparent rings 128, the topographical map 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.

[0149] The inner surface 141 faces the central channel 124. The inner surface 141 and the outer surface 142 of the light guide body 102 can be polished so as to be used as reflective or refractive optical surfaces.

[0150] The transparent rings 128 are integrated with the light guide body 102. In the illustrated embodiment, the reference object 103 is (or more precisely the opaque ring 129) sprayed or otherwise applied to the light guide body 102. In another embodiment, the spraying (or other application) can include the application of the opaque ring 129 and the transparent rings 128. In yet another embodiment, the reference object 103 can include a cover 149 (not shown), the cover 149 includes a transparent sheet 151, and an opaque ring 134 is included on the transparent sheet 151. In this embodiment, the opaque ring 129 can be printed on the sheet 151. Then the cover 149 is positioned inside the central channel 124 such that the printed opaque ring 129 extends along the length of the central channel 124.

[0151] In Figure 1A and Figure 1B In the illustrated embodiment, the reference object 103 includes thirty transparent rings 128. According to the teachings herein, a person skilled in the art can easily select other suitable reference objects and other suitable numbers of image strip generating features. For example, the reference object 103 can include 5 to 50, 10 to 40, or 20 to 35 transparent rings or other image strip generating features.

[0152] Figure 2A and Figure 8A It is also shown that in order to provide uniform illumination of the annular member 126, the light guide body 102 can include a plurality of light guide segments 130. In Figure 2A and Figure 8A In the illustrated embodiment, the light guide body 102 includes three segments 130i, 130ii, and 130iii. Each segment 130 includes a corresponding coupling efficiency, and the corresponding coupling efficiencies are matched so as to provide uniform illumination of each transparent ring 126 along the length of the reference object 103. Each segment 130 can include any number of transparent rings 128 and opaque rings 129.

[0153] In other embodiments, the light guide body 102 may include one, two, four, five, six, seven, eight, nine, ten segments or more than ten segments 130. The number of segments 130 may be selected to provide sufficient illumination.

[0154] In the illustrated embodiment, each segment 130 includes a coupling efficiency to produce a uniform illumination annular image on at least one imaging sensor 1116.

[0155] Importantly, the light guide body 102 includes a higher coupling efficiency compared to the coupling efficiency of the topographic illumination source 105, which includes the distributed illumination source 200 and the profile optical device illumination source 201, radiating into free space.

[0156] As Figure 8A shown, each light guide segment 130 and a part or all of the outer surface 142 may include an optical isolation cover 131 to prevent light leakage into other light guide segments and / or to prevent or reduce light coupling out of the light guide body 102.

[0157] Segment 130(i) includes a target segment, which may be colored or otherwise include a visible marker to provide a target for the gaze of the eye 106 viewing through the central channel 124. In the illustrated embodiment, although not visible in the black and white drawing, the target segment 130(i) is colored green. The target segment 130(i) is shown as being disposed at the distal end of the light guide body 102. All other segments 130(i), (ii) may have the same transparent material but differ from 130(i) in size and coupling efficiency and are preferably distinct.

[0158] Figure 2A Components for corneal topography according to one embodiment of the present invention are shown, while Figure 2B Components for profile imaging according to one embodiment of the present invention are shown. Figure 8A And 8B Further explanations are provided, which respectively show the optical paths for the central topographic optical system 150 and the profile system 172.

[0159] As Figure 2A And 2B Both shown, by including the topographic illumination source 105 ( Figure 2A ) and the profile optical device illumination source 201 ( Figure 2B) The light guide illumination array 155 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 profile optical device illumination source 201 are distinguishable. The topographic illumination source 105 and the profile optical device illumination source 201 can emit light of sufficiently different wavelengths such that there is no interference of images on at least one imaging sensor 116.

[0160] 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.

[0161] The topographic illumination source 105 includes the distributed illumination source 200 and thus includes a plurality of individual illumination sources in the form of topographic illumination LEDs 153 that emit multi - colored light 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 figure is provided, in the illustrated embodiment, the topographic illumination source 105 includes an outer annular member 105(a) and an inner annular member 105(b).

[0162] Figure 8A Three light paths of the light emitted by the topographic illumination source 105 including the LEDs 153 are shown. Some light has a light path such as the topographic light path 206a and is completely coupled out of the light guide body 102 from the outer surface 142. Other light partially takes the topographic light path 206b and partially takes the topographic light path 206c. In the topographic light path 206b, the light rays are partially coupled out of the light guide body 102 from the outer surface 142; in the topographic light path 206c, the light rays are reflected from the outer surface 142 towards the inner surface 141 on the eye 106 before passing through the central channel 124 to be incident on at least one imaging sensor 116. That is, the light within the light guide body 102 can be separated at the outer surface 142 and partially refracted and directed into the surrounding environment. The light path 206d shows that the light rays, before passing through the central channel 124 and the central imaging system 123 to be incident on at least one imaging sensor 116 to form the corneal image 204, do not pass through the outer surface 142 and pass towards the inner surface 141 and are incident on the eye 106. That is, the image strip 126 is imaged on the imaging sensor 116.

[0163] Turn to Figure 2B, shows that the contour optical device illumination source 201 includes a contour point source 202 in the form of a single LED that emits infrared light. The light from the point source 202 passes through the light guide body 202 and is guided by directing the optical system across the corneal contour 110 so as to be received by the reflective optical system 111 and directed to the contour imaging system 112 so as to be directed to a capture system 113 and at least one imaging sensor 116 that form and capture a contour image 205.

[0164] The directing optical system 108 is shown to include a mirror 133, and the reflective optical system 111 is shown to include a prism 143. In other embodiments, this arrangement is reversed with the directing optical system 108 including a prism and the reflective optical system 111 including a mirror.

[0165] The contour imaging system 112 is shown to include a mirror 133 and other components that direct the light propagation direction vector 134 to the capture system 113.

[0166] From Figure 2A and Figure 2B It can be seen that imaging is performed using a capture system 113 shown to include 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).

[0167] Figure 2A It is also shown that the relative positions of the light guide body 201 and the eye 106 can be moved (such as using a locator 167). This is advantageous because it allows for the convenient positioning of the eye 106 for each respective optical system 300a, 300b, 300c, 300d included in the interchangeable optical system 300. In Figure 3A , Figure 3B , Figure 3C and Figure 3D In the embodiment shown, the interchangeable optical system 300 is arranged on a locator 301 in the form of a wheel 302, which can be rotated in each direction to accurately align each respective optical system 300a, 300b, 300c, 300d in the central channel and with one or more capture systems 113.

[0168] As Figure 3A shown, the wheel 302 includes a perforation 308 for the axis of the central channel 144 of the central topographic system 150.

[0169] The wheel 302 can be rotated in either a clockwise or counterclockwise direction, as shown by the arrow in Figure 3A .

[0170] The wheel 302 includes indexing positions 303 that engage with one or more teeth. In Figure 3A 、 Figure 3B 、 Figure 3C and Figure 3D the illustrated embodiments, one or more teeth 309 including single teeth may be disposed on a pivot lever 305 that acts as a spring 304.

[0171] The wheel 302 includes one or more indexing positions 303 for precise positioning of each of two optical systems. In Figure 3A 、 Figure 3B 、 Figure 3C and Figure 3D 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 appropriate indexing positions 303a, 303b, 303c, 303d for engagement with one or more teeth 309, the corresponding optical systems 300a, 300b, 300c, 300d can be accurately positioned relative to the central channel 124 for imaging the eye 106.

[0172] Figure 3A One or more teeth 309 are shown that are not engaged with the wheel 302, which transitions between two indexing positions 303. Figure 3B The wheel 302 is shown rotating further such that when the wheel 302 and the pivot lever 305 snap back to engage with the wheel 302, one or more teeth 309 are now engaged.

[0173] Figure 3D Another embodiment of the locator 301 is shown that uses a sliding element 306 instead of using a pivot lever 305.

[0174] Although not shown, the locator 301 further includes one or more actuators 307 in the form of an electric motor 421 for effecting rotation.

[0175] Figure 4 Another embodiment of the locator 301 is shown that includes an electric motor 421 that drives a belt 422 to effect rotation of the wheel 302. In another embodiment, the wheel 302 includes gears.

[0176] In Figure 3D the illustrated embodiment, 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.

[0177] The positioner 301 is a backlash-free positioner that advantageously provides precise positioning and prevents or at least reduces undesired movement.

[0178] 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 may include different distinguishable colors that indicate the modality in use, such as the central topographic map system 150, the contour system 172, or one of the corresponding interchangeable optical systems 300.

[0179] 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. The coupled-out light can also be used to illuminate the eye 106 in addition to other illumination means for imaging the eye 106 or for imaging the surrounding area of the subject's eye 106.

[0180] The light coupled out and visible to the user or the tested subject may contain information about the operating state or additional information of the topographer 100. The light information may be presented in the form of color as a preferred embodiment, but may also contain other light modulations like light pulses or varying brightness.

[0181] 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 .

[0182] Figure 7A A contour image 205 (left hand side) and a corneal image 204 (right hand side) are shown. Figure 7A Also advantageously shown, the contour data includes contour outline 137 and vertex position 138. Reference position 139 may be applied to determine the position of eye 106 relative to reference 130 or central imaging system 123. These images 204, 205 can be reconstructed using data captured from one or more capture systems 113.

[0183] 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 A front image of the eye is shown. 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 7Ecan be obtained using optical systems 300a, 300b, 300c, and 300d, respectively.

[0184] Another significant advantage of the interchangeable optical system 300 is that each of the optical systems 300a, 300b, 300c, 300d, etc. is complete and does not require any other imaging elements, isolated or shared between each of the component interchangeable optical systems 300a, 300b, 300c, 300d, etc., or generally from the topographer 100. This allows more than one imaging function to be performed.

[0185] Figure 5 A schematic diagram of a prior art device for imaging the corneal profile is shown. The cross-sectional view shows the prior art profiling optics and the corresponding optical path outside (or mostly outside) the light guide body.

[0186] This is in contrast to the profiling system 172 and the profiling optical path 206 shown in Figure 8B which passes through the light guide body 102.

[0187] Figure 8B The profiling optical path 206 of the light emitted by the profiling optics illumination source 201 is shown. The light passes through the transparent medium 104 to the directional optical system 108 and the reflective optical system 111 at opposite points mounted on the proximal end 109 of the light guide body 102. The directional optical system 108 includes a mirror 143 that guides the transmitted light across the corneal profile 110 along a portion of the profiling optical path 206 between the mirrors 143 and the prism 143 included in the reflective optical system 111.

[0188] The reflective optical system 111 reflects the directional light from the directional optical system 108 that has passed through the corneal profile 110 and aims the directional light back through the light guide body 102 to the profiling imaging system 112 and to one or more capture systems 113.

[0189] At least a portion of the light captured by the directional optical system 108 is incident on the reflective optical system 111 disposed adjacent to the distal end 110 of the cone 100. The profiling image 206 includes information about the distance of the subject's eye 190 from a reference point. The distance information is used together with the information included in the corneal image to obtain corneal curvature information. The distance information is derived by measuring the profile contour 137 of the profiling image 205 and comparing its vertex position 138 with a reference position on the profiling image 205.

[0190] As Figure 2BAs shown, the contour imaging system 112 also includes one or more focusing lenses 135 to focus the contour plane of the eye 106 onto at least one imaging sensor 116. The contour imaging system 112 can be designed to correct the optical path length through the light guide body 102.

[0191] Figure 2B Also shown is that the contour imaging system 112 further includes a filter 254 that transmits only or substantially only infrared light from the contour optical device illumination source 201.

[0192] On the light guide body 102 for light propagation for eye contour imaging, the surface is substantially perpendicular to the light propagation direction vector 134. That is, the guiding optical system and the reflecting optical system reflect light substantially at a right angle, and both propagation direction vectors intercept the axis of the central channel at a right angle.

[0193] Additional light may need to be provided to the central topographic system 105. Figure 6 A cross-sectional schematic view of the topographer 100 is shown, which shows the relative position of the external illuminator 207 with respect to the light guide body.

[0194] The external illuminator 207 is outside the plane of the light guide body 102, so it is different in position from the illumination array 155 that is centered or internally located in the same plane as the light guide body 102 and the topographic illumination source and the contour imaging illumination source 201.

[0195] The external illuminator 207 includes a light source 208 that provides additional illumination, such as Figure 6 and Figure 9 as shown. In the illustrated embodiment, the light source 208 includes an LED.

[0196] Turning Figure 10 、 Figure 11A and Figure 11B , the topographer 100 may further include a scleral measurement device 400. The scleral measurement device 400 includes one or more scleral projection systems 401, and each scleral projection system 401 includes a scleral projection light source 406 and a scleral reference object 402.

[0197] The scleral reference object 402 includes at least one aperture 415, and the at least one aperture 415 includes 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. In Figure 11A , the corneal scatter image 419 passes through the cornea, so the measurement is performed through the eye in volume scattering.

[0198] One or more scleral projection systems 401 also include a scleral projection imaging system 403 shown as including one or more lenses.

[0199] In Figure 10 the illustrated embodiment, one or more scleral projection systems 401 include two symmetrically arranged scleral projection systems 401, with one scleral projection system 401 mounted on each side of the topographer 100. The symmetrically mounted scleral projection systems 401 can 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, namely 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 parts of the eye surface.

[0200] The scleral aperture pattern 405 illuminated by the scleral projection light source 406 can be imaged onto the scleral projection imaging system 403 and onto the scleral 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 onto the cornea 107.

[0201] The scleral measurement device 400 also includes one or more scleral registration reference projectors 404, which include a scleral reference light source 408 and a scleral registration reference 407. The scleral registration reference 407 can include a registration reference light guide 409, which optionally can be provided in the form of two or more concentric rings and can include a second Placido disk. The light from the scleral reference light source 408 passing through the scleral registration reference 407 can be reflected from the eye surface and imaged onto one or more image capture systems 113 by the imaging system 123.

[0202] The light from the scleral reference light source 408 passes through the scleral registration reference 407 and is reflected from the eye surface to form a scleral image 410, which is digitally processed to obtain corneal height information and scleral position and includes scleral height information. Those familiar with corneal topography understand that the height information and curvature information of the eye 106 are conjugate and contain the same information. The scleral height information and scleral curvature information can be converted from one to the other by applying well-known mathematical means.

[0203] The processed scleral image 410 can be used to combine the corneal height information from the topographer 100 with the scleral height information into a new scleral topogram. This combination can include image registration. The registration can utilize one or more scleral locators 418 in the scleral locator 418, the corneal scatter image 419, and the scleral registration reference image 420.

[0204] 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 disposed 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 one or two or more adjacent transparent and opaque alternating rings (concentric with the axis of the central channel 124) to form a second Placido disk 416. As Figure 13 shown, the two or more adjacent registration apertures 423a include three transparent rings. In yet another embodiment, the rings can be used as a reference aperture and can be used in conjunction with the alternating rings 418.

[0205] The scleral aperture pattern 405 projected on the eye surface and the registration aperture 423 can be imaged together on one or more capture systems 113 in the same image. From these two adjacent annular or dot-shaped members of the registration aperture 423, curvature information and height information of the reflected eye surface can be derived.

[0206] The scleral measurement device 400 can also apply an algorithm to improve the accuracy of the scleral height information by comparing the eye reference axis of the scleral image 410 with the eye reference axis of the corneal image 204. The reference axis can include the axis of the eye 106 to the central channel 124 or the rotational information between the eye 106 and the central channel 122.

[0207] 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.

[0208] Advantageously, the pupil 413 can be captured in both the scleral image 410 and the corneal image 204, wherein the captured pupil information can provide information about the eye reference axis. Additionally or alternatively, other uniquely identifiable scleral features can be used to combine the corneal and scleral height information.

[0209] Furthermore, the pupil center position of the eye 106 relative to the axis of the central channel 124 can be measured to provide reference data for combining the corneal and scleral height information.

[0210] The use of the scleral measurement device 400 as part of the topographer 100 allows the combination of scleral data with corneal topographic data. Advantageously, this does not rely on scattered images but uses reflected images of the cornea. Additionally, the relative pupil positions of both eyes can be measured to provide reference data for image registration.

[0211] One advantage of the present invention is that since the illumination is no longer located outside the light guide body 102, the diameter at the proximal end 113 can be reduced. This allows the corneal surface 148 to be closer to the light guide body 102 and thus allows a larger corneal portion to be analyzed.

[0212] Another advantage of the present invention is that the illumination no longer causes shadows that affect the light distribution. The present invention also greatly reduces the number of components required for illumination and the complexity of manufacturing.

[0213] In this specification, the terms "comprises", "comprising", or similar terms are intended to mean non-exclusive inclusion, such that a device that includes a list of elements not only includes those elements but may also include other elements not listed.

[0214] Throughout the specification, the aim is to describe the present invention without limiting the present invention to any one embodiment or specific set of features. Those skilled in the relevant art can implement variations from the specific embodiments but still fall within the scope of the present invention.

Claims

1. An ophthalmic topographer, comprising: A corneal topographer that guides a topographic reference object onto the eye surface; And A scleral measurement device, the scleral measurement device including one or more scleral projection systems, wherein each of the one or more scleral projection systems includes a scleral projection light source and a scleral reference object, the scleral reference object including at least one aperture, the at least one aperture including two or more adjacent registration apertures through which light can propagate and which are arranged on the cornea; And Wherein, the data collected by the corneal topographer is combined with the data collected by the scleral measurement device to determine the topographic information of the eye surface.

2. The ophthalmic topographer according to claim 1, wherein, The guided topographic reference object includes a projection reference object or an image strip.

3. The ophthalmic topographer according to claim 2, wherein, The image strip includes a pattern of the reference object, and wherein, the pattern reflected by the curved surface of the cornea is used to calculate the topographic map of the cornea.

4. The ophthalmic topographer according to claim 3, wherein, The reference object includes a plurality of rings or a Placido disk.

5. The ophthalmic topographer according to any one of claims 1 to 4, further comprising a topographic illumination source.

6. The ophthalmic topographer according to any one of claims 1 to 4, including an imaging system that images the topographic reference object guided onto the eye surface through a central channel in the topographer body.

7. The ophthalmic topographer according to claim 1, wherein, The one or more apertures are arranged in an aperture pattern.

8. The ophthalmic topographer according to claim 7, wherein, The one or more apertures include a scleral aperture pattern.

9. The ophthalmic topographer according to claim 7, wherein, The one or more apertures include a corneal aperture pattern.

10. The ophthalmic topographer according to claim 7, wherein, The one or more apertures include a scleral aperture pattern and a corneal aperture pattern.

11. The ophthalmic topographer according to claim 8 or claim 10, wherein, When imaged on the eye or an imaging sensor, the scleral aperture pattern is imaged as one or more scleral locators.

12. The ophthalmic topographer according to claim 9 or claim 10, wherein, When imaged on the eye or an imaging sensor, the corneal aperture pattern is imaged as a corneal scatter image.

13. The ophthalmic topographer according to any one of claims 1 to 4, 7 to 10, wherein, Each of the one or more scleral projection systems further includes a scleral projection imaging system.

14. The ophthalmic topographer according to any one of claims 1 to 4, 7 to 10, wherein, The one or more scleral projection systems are symmetrically mounted on the ophthalmic topographer.

15. The ophthalmic topographer according to claim 13, wherein, The scleral aperture pattern illuminated by the scleral projection light source is imaged onto the scleral projection imaging system and onto the scleral part of the eye surface.

16. The ophthalmic topographer according to claim 13, wherein, The corneal aperture pattern illuminated by the scleral projection light source is imaged onto the scleral projection imaging system and onto the cornea.

17. The ophthalmic topographer according to any one of claims 1 to 4, 7 to 10, further comprising one or more scleral registration reference object projectors.

18. The ophthalmic topographer according to claim 17, wherein, The scleral registration reference object projector includes a scleral reference light source and a scleral registration reference object.

19. The ophthalmic topographer according to claim 18, wherein, The scleral registration reference object projector includes a registration reference object light guide.

20. The ophthalmic topographer according to claim 18 or claim 19, wherein Light from the scleral reference light source passes through the scleral registration reference object and is reflected from the eye surface to form at least a part of the scleral image.

21. The ophthalmic topographer according to claim 20, wherein, The light from the scleral image is digitized to obtain corneal height information and scleral height information.

22. The ophthalmic topographer according to any one of claims 1 to 4, 7 to 10 further includes a processor, and the processor combines the scleral height information obtained from the scleral measurement device with the corneal height information obtained from the corneal topographer.

23. The ophthalmic topographer according to claim 21, wherein, The processed scleral image is used to combine the corneal height information from the corneal topographer with the scleral height information into a new scleral topography map.

24. The ophthalmic topographer according to claim 23, wherein, The combination includes image registration.

25. The ophthalmic topographer according to claim 8, wherein, The projected scleral aperture pattern and the registration diaphragm on the eye surface can be imaged together onto one or more capture systems in the same scleral image.

26. The ophthalmic topographer according to claim 25, wherein, One or more scleral reference apertures and / or scleral registration apertures are imaged onto one or more imaging sensors by the imaging system.

27. The ophthalmic topographer according to any one of claims 1 to 4, 7 to 10, wherein, The scleral measurement device further applies an algorithm to improve the accuracy of the scleral height information by comparing the eye reference axis of the scleral image with the eye reference axis of the corneal image.

Images