Anterior eye imaging using a retinal camera for assessing eye abnormalities

Abstract

A technique for imaging an eye with a retinal imaging system includes: setting an illumination pattern of a dynamic illuminator to illuminate a pupil and at least a portion of an iris of the eye during anterior eye imaging; setting an imaging focal length of a retinal image sensor to focus on an anterior portion of the eye including a crystalline lens of the eye during the anterior eye imaging; capturing anterior eye images of an abnormality in or on the crystalline lens with the retinal image sensor; and characterizing the abnormality based upon the anterior eye images.

Description

ANTERIOR EYE IMAGING USING A RETINAL CAMERA FOR ASSESSING EYE ABNORMALITIESCROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to U.S. Provisional Application No.63 / 751,549, filed on January 30, 2025, the contents of which are incorporated herein by reference.TECHNICAL FIELD

[0002] This disclosure relates generally to ophthalmic imaging, and in particular, relates to cataract imaging using a retinal camera.BACKGROUND INFORMATION

[0003] Retinal imaging is a part of basic eye exams. A high-fidelity retinal image is important for accurate screening, diagnosis, and retinal disease progress monitoring.

[0004] Cataracts are a leading cause of blindness. Cataracts not only affect the patient’s vision, but can also deleteriously impact retinal imaging quality, thereby compromising the accuracy of a retinal disease diagnosis. FIG. 1A illustrates three different example cataracts. Cataracts may form in the nuclear portion of the human crystalline lens (nuclear cataract), on the posterior surface of the crystalline lens (posterior subcapsular), the anterior surface of the crystalline lens (anterior subcapsular), or a combination thereof. The presence of a cataract in or on crystalline lens 100 of a diseased eye 101 can lead to scattering of light 105 entering the diseased eye 101 relative to a healthy eye 102 (see FIG. IB). Forward scattering onto retina 110 negatively affects the patient’s vision while backscattering can negatively affect retinal imaging.

[0005] Cataract surgery is an effective treatment option for high-grade cataracts, but the decision for surgery7should be based on accurate assessment of a cataract condition. A conventional cataract assessment is a manual process performed by an eye doctor using slip lamp examination. These exams can be expensive since they require examination by a highly skilled practitioner and the manual assessments lack an automated capability7of recording results for long term follow up and disease progression monitoring.13960-P485WO

[0006] Accordingly, an ophthalmic imaging system that can quickly and economically image and assess cataracts in an automated fashion without requiring operation by a highly trained eye doctor would be desirable. Such a system may be capable of increasing the confidence in, and accuracy of, retinal imaging while also increasing the availability7of cataract assessments and reliable long-term cataract monitoring.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Non-limiting and non-exhaustive embodiments of the invention are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified. Not all instances of an element are necessarily labeled so as not to clutter the drawings where appropriate. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles being described.

[0008] FIG. 1A (PRIOR ART) illustrates three example cataracts forming in or on the crystalline lens of a human eye.

[0009] FIG. IB (PRIOR ART) illustrates how the presence of a cataract in or on the cry stalline lens of a human eye causes deleterious artifacts in a retinal image due to light scattering, relative to a healthy crystalline lens.

[0010] FIG. 2 is a functional block diagram illustrating a retinal imaging system capable of both cataract and retinal imaging, in accordance with an embodiment of the disclosure.

[0011] FIG. 3 illustrates a dynamic illuminator capable of generating different illumination patterns during cataract or retinal imaging, in accordance with an embodiment of the disclosure.

[0012] FIG. 4A is a flow chart illustrating a process for cataract imaging using a retinal imaging system, in accordance with an embodiment of the disclosure.

[0013] FIG. 4B is a flow chart illustrating a process for retinal imaging informed by characterization of a cataract using a retinal imaging system, in accordance with an embodiment of the disclosure.

[0014] FIG. 5A illustrates an illumination pattern configured for cataract imaging, in accordance with an embodiment of the disclosure.23960-P485WO

[0015] FIG. 5B illustrates transillumination and direct scattering components that are characterized from a set of cataract images, in accordance with an embodiment of the disclosure.

[0016] FIG. 5C illustrates sequential adjustment of an illumination pattern during cataract imaging to image the cataract from a plurality of different perspectives, in accordance with an embodiment of the disclosure.

[0017] FIG. 6A illustrates an illumination pattern configured for retinal imaging, in accordance with an embodiment of the disclosure.

[0018] FIG. 6B illustrates setting an imaging focal length to focus on a posterior portion of an eye for retinal imaging, in accordance with an embodiment of the disclosure.

[0019] FIG. 7 illustrates how characterization of a cataract may be used to inform illumination patterns during retinal imaging to reduce direct scattering from a cataract and improve retinal image quality, in accordance with an embodiment of the disclosure.DETAILED DESCRIPTION

[0020] Embodiments of a system, apparatus, and method of operation for a retinal imaging system capable of cataract imaging and characterization as well as retinal imaging informed by the cataract characterization are described herein. In the following description numerous specific details are set forth to provide a thorough understanding of the embodiments. One skilled in the relevant art will recognize, however, that the techniques described herein can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring certain aspects.

[0021] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.33960-P485WO

[0022] Unlike slit lamp examinations, retinal cameras often do not require an eye physician (e.g.. ophthalmologist) as an operator. Rather these tools are often operated by an optometrist or even an ophthalmic technician, thereby making retinal imaging more accessible to patients than slit lamp examinations. While some conventional retinal cameras may have limited anterior eye imaging functionality to record external parts of the eye, they do not have the ability to capture detailed information about cataracts, as they capture general eye images from the same viewing angle and illumination angles as used for retinal imaging. Embodiments described herein describe a retinal camera system that may be operated by a variety7of lesser trained technicians, or even the patients themselves, while being capable of posterior eye imaging (e.g., retinal imaging) and detailed three-dimensional (3D) anterior eye imaging of the crystalline lens (e.g., cataract imaging). The anterior images (e.g., cataract images) may then be analyzed using analytical methods, machine learning, or otherwise by an onboard controller to characterize the cataract (e.g., fit the cataract to a two-dimensional (2D) density function, map a perimeter shape of the cataract, grade the cataract, etc.), and then use the characterization to adjust illumination patterns during retinal imaging to improve retinal imaging quality7. Of course, the anterior images may also be used to image and characterize other eye abnormalities in the anterior portion of the eye, such as local inflammations on the crystalline lens, etc. These and other features are described in greater detail below.

[0023] FIG. 2 is a functional block diagram illustrating a retinal imaging system 200 capable of performing both retinal and cataract imaging, in accordance with an embodiment of the disclosure. System 200 includes a dynamic illuminator 205, a retinal image sensor 210, a controller 215, a micro display 225, pupil tracking cameras 230, infrared (IR) illuminators 231, and an optical assembly (e.g., lens assemblies 235, 240, 245 and a beam splitter 250). The illustrated embodiment of dynamic illuminator 205 includes illuminator arrays 265 disposed around a center aperture 255 through which image light passes.

[0024] The optical assembly serves to direct (e.g., pass, reflect, focus) illumination light 280 output from dynamic illuminator 205 along an illumination path through the pupil of eye 270 to illuminate retina 275 while also directing image light 285 of retina 275 (i.e., the retinal image) or a cataract image along a return imaging path to retinal image sensor 210. When imaging the retina, image light 285 is formed by the scattered reflection of illumination light 280 off of retina 275. When imaging a 43960-P485WOcataract, image light 285 includes direct scattering off of the cataract and transillumination of light reflected off retina 275 back through the cataract. The optical assembly passes at least a portion of image light 285 to retinal image sensor 210 while also optically coupling display light 290, including a fixation target 291, to lens 235. The optical assembly includes a number of lens assemblies, such as lenses 235, 240, and 245, to focus the various light paths as needed. For example, lens assembly 235 may include one or more lensing elements that collectively form an eyepiece lens assembly.

[0025] In one embodiment, the optical assembly is adapted to permit independent or separate adjustment of the imaging focal length of retinal image sensor 210 from an illumination focal length of dynamic illuminator 205. This separate or independent adjustment may be accomplished using adjustable power for lens assemblies 240 and / or 235, having adjustable z-axis offsets for retinal image sensor 210 and / or dynamic illuminator 205, or a combination thereof. The lenses, retinal image sensor 210, and / or dynamic illuminator 265 may be actuated (e.g., motorized) under the influence of controller 215 to adjust optical power or z-axis offsets. During retinal imaging, the illumination pattern output from dynamic illuminator 205, which may include the illumination focal length, are adjusted to constrain the illumination beam spread to pass through the pupil to illuminate retina 275 while avoiding scattering off of the iris (see FIG. 6A). In contrast, during cataract imaging the illumination pattern output from dynamic illuminator 205 along with the illumination focal length are adjusted to more broadly illuminate eye 270, including the pupil and at least a portion of the iris. In one embodiment, the illumination focal length is adjusted to complement a focal length of eye 270 such that illumination from dynamic illuminator 205 is substantially collimated after passing through the crystalline lens and illuminating retina 275. Accordingly, the optical assembly and dynamic illuminator 205 are reconfigurable between cataract and retinal imaging.

[0026] Referring to FIGs. 2 & 3, dynamic illuminator 205 is capable of illuminating eye 270 from multiple different selectable radial / angular positions around aperture 255 when capturing retinal / cataract images. In one embodiment, dynamic illuminator 205 is implemented as arrays 265 of light emitting diodes (LEDs) positioned about aperture 255 (see FIG. 3). The LEDs may be arranged in rings or other patterns and may include both white light LEDs (for flashing color retinal images) and infrared (IR) LEDs for IR images, alignment, and / or autofocus. During 53960-P485WOretinal imaging, the various illumination patterns may help correct or alleviate misalignments between eye 270 and eyepiece lens 235, effectively enlarging the eyebox compared to static retinal illumination. The eyebox is a 3D region in space in which the center of the pupil must reside in order for a retinal camera system to acquire a useful retinal image 101 without undue artifacts. The dynamic nature of the illumination pattern enlarges this eyebox thereby alleviating the alignment burden. During cataract imaging, the various illumination patterns enable illumination from different perspectives to capture a set of cataract images that facilitate better characterization of the cataract, similar to how slit lamp examination uses multi-angle illumination. Changes in the illumination pattern (i.e., radial and angular position along with illumination intensity) are selectable by controller 215 and may even be determined in real-time by controller 215 based upon feedback from pupil tracking cameras 230 and / or retinal image sensor 210. In other words, the different source locations and / or beam spread may be adjusted by controller 215 based upon whether cataract or retinal imaging is being performed. During retinal imaging the individual LEDs may further be dynamically activated based upon a lookup table that maps pupil position (determined by pupil tracking cameras 230) to illumination position / pattem and maps pupil size (also determined by pupil tracking cameras 230) to illumination intensity. Dynamic illumination reduces unwanted comeal reflections despite modest misalignment of eye 270 during retinal imaging while facilitating variable perspective illumination during cataract imaging and characterization.

[0027] Display light 290 output from display 225 presents a fixation target 291 viewable through eyepiece lens 235 by the patient. Fixation target 291 gives the patient a point of fixation upon which to accommodate and stabilize their vision. An example fixation target 291 may be a plus-sign, concentric rings, or another image.

[0028] Retinal image sensor 210 is a full frame 2D image sensor. Retinal image sensor 210 acquires the retinal / cataract images through eyepiece lens 235 using white light illumination and / or IR illumination from dynamic illuminator 205. In some embodiments, IR illuminators 231 of the pupil tracking system may also be used during acquisition of one or more cataract images.

[0029] In one embodiment, controller 215 may be implemented as a microprocessor with an integrated image signal processor (ISP) and associated buffer memory. Controller 215 is coupled to retinal image sensor 210. micro display 225, dynamic illuminator 205, pupil tracking cameras 230, and IR illuminators 231 to 63960-P485WOchoreograph their operation. When eye 270 is sufficiently aligned within the eyebox of the system, controller 215 issues an auto-capture trigger to retinal image sensor 210 to capture a burst of retinal / cataract images in short succession. For example, a burst of 30 retinal images may be acquired before the user recoils or blinks due to the white light flash illumination from retinal illuminator 205, thereby losing alignment. Finally, controller 215 is capable of analyzing the retinal / cataract images and computing an image quality score or cataract grade, mapping the contours / perimeter shape of a cataract, fitting a 3D density function to the cataract, or otherwise. Controller 215 may use image stacking to register and combine multiple eye images into a single high quality composite image that removes image artifacts and / or more fully captures an image of a cataract or retina 275. Multiple eye images illuminated by different illumination patterns may also be ‘'stitched” together to obtain wider field of view (FOV).

[0030] FIG. 4A is a flow chart illustrating a process 400 for cataract imaging using retinal imaging system 200. in accordance with an embodiment of the disclosure. Process 400 is described with reference to FIGs. 5A, 5B, and 5C. The order in which some or all of the process blocks appear in process 400 should not be deemed limiting. Rather, one of ordinary skill in the art having the benefit of the present disclosure will understand that some of the process blocks may be executed in a variety of orders not illustrated, or even in parallel.

[0031] Tn a process block 405, anterior eye or cataract imaging is commenced when the patient places their eye in front of retinal imaging system 200. In process block 410, the illumination pattern output from dynamic illuminator 205 is set to and configured for cataract imaging (or other anterior eye anomaly imaging). In other words, dynamic illuminator 205 is configured to illuminate the anterior of the eye. This anterior illumination configuration more broadly illuminates eye 270 for cataract imaging than compared to retinal imaging of the posterior portion of eye 270. The broad illumination illuminates the pupil along with at least a portion of the iris. This is distinct from a posterior illumination pattern, which seeks to avoid broad illumination patterns that will illuminate the iris, causing deleterious specular reflections in the retinal images.

[0032] In one embodiment, a divergence of the broad illumination pattern may be specifically tuned to match the prescription or optical power of the patient’s eye. For example, FIG. 5A illustrates an illumination pattern 505 where an 73960-P485WOillumination focal length of dynamic illuminator 205 is set to complement a focal length of eye 270 (e.g., focal length of crystalline lens 100) such that the illumination pattern 505 output from dynamic illuminator 205 becomes substantially collimated light 510 after passing through crystalline lens 100 and impinging on retina 275. The retroreflection of collimated light 510 is suitable for transillumination of cataract 520. In some embodiments, only a portion of retina 275 is illuminated at a time so that the illumination does not fully spread throughout the entire retina 275. This limited spot illumination provides illumination boundaries that help elucidate the structure of cataract 520. The illuminated spot may be sequentially moved to help define the perimeter shape of cataract 520 from the transillumination. The illumination focal length may be adjusted in a variety of ways including adjusting a separation distance 515 between dynamic illuminator 205 and eyepiece lens assembly 235, adjusting a focal power of eyepiece lens assembly 235, adjusting output divergence of dynamic illuminator 205 itself, adjusting other illumination optics (not illustrated), or combinations thereof.

[0033] In a process block 415, the imaging focal length is focused on the anterior portion of eye 270, which includes crystalline lens 100, when imaging cataract 520. This is distinct from retinal imaging when the imaging focal length is focused onto the posterior portion of eye 270 including the retinal plane. Adjustment of the imaging focal length may be achieved by translating retinal image sensor 210 along the z-axis, adjusting an optical power of lens assembly 240 (see FIG. 2), adjusting other optical elements (not illustrated), or a combination thereof. In one embodiment, the imaging focal length of retinal image sensor 210 is separately or independently adjustable from the illumination focal length.

[0034] Once retinal imaging system 200 is configured for cataract imaging (anterior eye imaging), one or more cataract images are acquired using retinal image sensor 210 (process block 420). In some embodiments, a series of cataract images may be acquired and the illumination pattern adjusted / changed sequentially between each cataract image (process block 430) to explore the structure, density, and perimeter shape (e.g., contours) of cataract 520. The cataract images continue until all desired cataract images with different illumination patterns are acquired (decision block 425). In one embodiment, incremental offsets are applied to an initial illumination focal length during anterior eye imaging. An example initial illumination focal length may be the complement of the focal length of eye 270. As the 83960-P485WOillumination focal length deviates from the complement of the eye focal length for generating collimated light on retina 275, the illumination spreads over a greater area of retina 275. This may be beneficial for patients with small pupils though at the expense of losing collimation as the source of the transillumination of cataract 520.

[0035] As illustrated in FIG. 5B, each cataract image may be captured as a combination of a transillumination pattern 530 from retroreflection of illumination light off of retina 275 transiting through cataract 520 and a direct illumination pattern 535 from light scattering directly off of cataract 520 itself. These image components may be identified from analyzing a series of the cataract images, which are used to solve a cataract estimation function F(x, y, z*), where x and y are coordinates in a 2D plane and z* is a density variable. In one embodiment, F(x, y, z*) may be described as a 2D density function in the x-y plane having a variable density over the 2D plane. The 2D density function may be fitted to the cataract images using analytical means, a machine learning (ML) model, or otherwise. The transillumination pattern 530 may be characterized as TI_n(F), where n represents a specific cataract image 1, 2, 3..., and the direct illumination pattern 535 may be characterized as DI_n(F). Thus, F(x, y, z*) may be solved by fitting it to the cataract images A, B, C... n using analytical or ML means.Illumination Pattern A: Image A = DI_A(F)+TI_A(F) Illumination Pattern B: Image B = DI B(F)+TI B(F)Illumination Pattern C: Image C = DI_C(F)+TI_C(F)Illumination Pattern n: Image n = DI_n(F)+TI_n(F)

[0036] FIG. 5C illustrates a series of example cataract images 540A, 540B, 540C, and 540D where the illumination pattern is sequentially adjusted (e.g., moved). The illumination pattern is readjusted between each cataract image 545 A-D, such that a transillumination pattern 545 moves about while a direct scattering pattern 550 from cataract 520 remains stationary. The readjusted illumination pattern causes a moving transillumination pattern 545 that helps define the boundary of cataract 520 and differentiate the transillumination image components from the direct scattering image components. The sequential adjustment of the illumination pattern between each cataract image (process block 430) may be achieved by activating different source locations (e.g., different individual or combinations of LEDs) within illuminator93960-P485WOarrays 265 of dynamic illuminator 205 to illuminate the eye from different perspectives or different locations.

[0037] As demonstrated above, illuminating cataract 520 in different ways and combinations helps to elucidate the 3D structure of cataract 520 for estimation and characterization thereof. The estimation can be performed analytically or using ML techniques. An example analytical method is analogous to the Beer-Lambert Law, using a negative exponential decay to estimate the "density ’ of the cataract from transillumination decay while the direct scattering is modeled as proportional to the illumination. For ML techniques, the cataract images may be input into a convolutional neural network or otherwise for labeling using conventional ML techniques.

[0038] Solving or fitting F(x, y, z*) to the cataract images is a form of characterization of cataract 520 (process block 435). Once F(x, y, z*) is solved / fitted, the perimeter shape of cataract 520 may be plotted and the cataract may even be labelled (e.g., nuclear cataract (NC), cortical cataract (CC), posterior subcapsular cataract (PS), anterior subcapsular cataract (NS), etc.) and / or graded (e.g., grade 1, 2, 3, 4). For example, the characterizing may include a 2D perimeter plot along with a NC3, CC2, PS4, etc. grading. As mentioned, the plot and grade may be derived using analytical methods to solve the above described 2D density function, output from a ML model trained to plot, label, and grade the cataract, or generated using other software algorithms.

[0039] FIG. 4B is a flow chart illustrating a process 401 for retinal imaging of retina 275 informed by characterization of cataract 520 using retinal imaging system 200. in accordance with an embodiment of the disclosure. Process 401 is described with reference to FIGs. 6A, 6B, and 7. The order in which some or all of the process blocks appear in process 401 should not be deemed limiting. Rather, one of ordinary' skill in the art having the benefit of the present disclosure will understand that some of the process blocks may be executed in a variety of orders not illustrated, or even in parallel.

[0040] Once cataract 520 has been characterized (e.g., via process 400), knowledge of the size, shape, position, and density / opaqueness of cataract 520 may be used to inform retina imaging of retina 275 commenced in process block 450. Retinal imaging system 200 is reconfigured to image the posterior portion of eye 270 where retina 275 resides by adjusting its illumination pattern (process block 455) and 103960-P485WOimaging focal length (process block 460). In process block 455, an illumination pattern 605 (see FIG. 6A) output from dynamic illuminator 205 is narrowed relative to the cataract illumination pattern 505 (see FIG. 5A). Narrowing the illumination pattern 605 may include adjusting (e.g., shortening) the illumination focal length so that illumination pattern 605 passes through the pupil without needlessly illuminating the iris or other exterior eye anatomy. The retinal illumination pattern 605 is narrowed to prevent deleterious reflections from the iris or other exterior eye anatomy. In some embodiments, illumination pattern 605 may also be customized based upon characteristics of cataract 520. For example, illumination pattern 605 may be tailored to avoid or reduce direct scattering off cataract 520, which results in artifacts in the retinal image. FIG. 7 illustrates an example retinal illumination pattern 705 made up of six illumination components 705A-F that illuminate around cataract 520 within pupil area 710 to reduce the amount of direct illumination that is passing through cataract 520 on the forward journey to illuminate retina 275. Retinal illumination pattern 705 is an example of retinal illumination pattern 605 illustrated in FIG. 6 A. Retinal illumination pattern 705 may activate each illumination component 705A-F simultaneously for a single retinal image exposure, or sequentially and use image stitching / stacking techniques to combine the individual retinal images into a composite retinal image. By directing the illumination components 705 A-F around cataract 520 and reducing the amount of direct backscattering into eyepiece lens 235, the retinal image quality is improved. Accordingly, the size, shape, position, and density of cataract 520 as characterized in process 400 may be used to inform a refined or optimized illumination pattern for retinal imaging in process 401.

[0041] Returning to FIG. 4B, in a process block 460, the imaging focal length of retinal camera system 200 is reset to focus on the posterior portion of eye 270 that includes the retinal plane (see FIG. 6B). With the illumination pattern and imaging focal length set for retinal imaging, and in some embodiments customized based upon the characterization of cataract 520, a retinal image is acquired (process block 465). Multiple retinal images may be acquired as part of a burst imaging sequence before the patient’s pupil constricts and the patient recoils / blinks. As mentioned above, the retinal imaging burst may include a sequential adjustment of the illumination pattern, referred to as burst illumination (process block 475), until all desired retinal images and illumination patern combinations are acquired (decision block 470). This may include acquiring 5, 10, 15, 20, 30, or more retinal images and 113960-P485WOpotentially as many different illumination patterns. Finally, in a process block 480, the various retinal images may be stitched together to obtain a broader FOV of retina 275 and / or stacked to remove artifacts present in some images but not others due to the varying illumination patterns.

[0042] The processes explained above are described in terms of computer software and hardware. The techniques described may constitute machine-executable instructions embodied within a tangible or non-transitory machine (e.g., computer) readable storage medium, that when executed by a machine will cause the machine to perform the operations described. Additionally, the processes may be embodied within hardware, such as an application specific integrated circuit (“ASIC”) or otherwise.

[0043] A tangible machine-readable storage medium includes any mechanism that provides (i.e., stores) information in a non-transitory form accessible by a machine (e.g., a computer, network device, personal digital assistant, manufacturing tool, any device with a set of one or more processors, etc.). For example, a machine-readable storage medium includes recordable / non-recordable media (e.g., read only memory (ROM), random access memory (RAM), magnetic disk storage media, optical storage media, flash memory devices, etc.).

[0044] The above description of illustrated embodiments of the invention, including what is described in the Abstract, is not intended to be exhaustive or to limit the invention to the precise forms disclosed. While specific embodiments of, and examples for, the invention are described herein for illustrative purposes, various modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize.

[0045] These modifications can be made to the invention in light of the above detailed description. The terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification. Rather, the scope of the invention is to be determined entirely by the following claims, which are to be construed in accordance with established doctrines of claim interpretation.123960-P485WO

Claims

CLAIMSWhat is claimed is:

1. A retinal imaging system, comprising:a retinal image sensor adapted to acquire retinal images of an eye;a dynamic illuminator adapted to illuminate the eye;an optical assembly positioned relative to the retinal image sensor to adjust an imaging focal length of the retinal image sensor; anda controller coupled to the retinal image sensor and the dynamic illuminator, the controller including logic that when executed by the controller causes the retinal imaging system to perform operations including:setting an illumination pattern of the dynamic illuminator for anterior eye imaging;setting the imaging focal length to focus on an anterior portion of the eye including a crystalline lens of the eye for the anterior eye imaging;capturing anterior eye images of an abnormality in or on the crystalline lens with the retinal image sensor; andcharacterizing the abnormality based upon the anterior eye images.

2. The retinal imaging system of claim 1, wherein the anterior eye imaging comprises cataract imaging, the anterior eye images comprise cataract images, and the abnormality comprises a cataract.

3. The retinal imaging system of claim 2, wherein setting the illumination pattern of the dynamic illuminator for the cataract imaging comprises:adjusting the dynamic illuminator to more broadly illuminate the eye during the cataract imaging compared to a retinal imaging with the retinal imaging system.

4. The retinal imaging system of claim 3, wherein the optical assembly is adapted to permit independent or separate adjustment of the imaging focal length of the retinal image sensor from an illumination focal length of the dynamic illuminator.

5. The retinal imaging system of claim 2, wherein setting the illumination pattern of the dynamic illuminator for the cataract imaging comprises:133960-P485WOseting an illumination focal length of the dynamic illuminator when capturing the cataract images to complement a focal length of the eye such that illumination from the dynamic illuminator is substantially collimated after passing through the cry stal I i ne lens and illuminating a retina of the eye.

6. The retinal imaging system of claim 5, wherein the operations further comprise:adjusting the illumination patern during the cataract imaging to offset the illumination focal length of the dynamic illuminator from the complement of the focal length of the eye by one or more increments during one or more of the cataract images.

7. The retinal imaging system of claim 2, wherein the operations further comprise:sequentially adjusting the illumination patern during the cataract imaging to illuminate the eye from a plurality of different source locations for imaging the cataract from different perspectives during different ones of the cataract images.

8. The retinal imaging system of claim 2, wherein characterizing the cataract based upon the cataract images comprises:fiting a two-dimensional (2D) density function to the cataract imaged in the cataract images, wherein the 2D density function has a variable density over a 2D plane.

9. The retinal imaging system of claim 2, wherein characterizing the cataract based upon the cataract images comprises:grading the cataract based upon the cataract images.

10. The retinal imaging system of claim 2, wherein characterizing the cataract based upon the cataract images comprises:mapping a perimeter shape of the cataract based upon the cataract images.

11. The retinal imaging system of claim 2, wherein the operations further comprise:143960-P485WOseting the illumination pattern for retinal imaging, wherein the illumination patern is narrower for the retinal imaging than the cataract imaging;seting the imaging focal length to focus on a posterior portion of the eye including a retina; andcapturing the retinal images with the illumination patern narrowed and the imaging focal length set for the retinal imaging.

12. The retinal imaging system of claim 11, wherein the operations further comprise:selecting one or more illumination paterns for the dynamic illuminator during the retinal imaging based upon the characterizing of the cataract to reduce illumination of the retina passing through the cataract.

13. A method performed by a retinal imaging system to image an eye, the method comprising:seting an illumination patern of a dynamic illuminator of the retinal imaging system to illuminate a pupil and at least a portion of an iris of the eye for cataract imaging;setting an imaging focal length of a retinal image sensor of the retinal imaging system to focus on an anterior portion of the eye including a crystalline lens of the eye for the cataract imaging;capturing cataract images of a cataract in or on the crystalline lens with the retinal image sensor; andcharacterizing the cataract based upon the cataract images.

14. The method of claim 13, wherein seting the illumination pattern of the dynamic illuminator for the cataract imaging comprises:adjusting the dynamic illuminator to more broadly illuminate the eye during the cataract imaging compared to a retinal imaging with the retinal imaging system.

15. The method of claim 14, further comprising:adjusting the imaging focal length of the retinal image sensor independently or separately from adjusting an illumination focal length of the dynamic illuminator.153960-P485WO16. The method of claim 13, wherein setting the illumination pattern of the dynamic illuminator for the cataract imaging comprises:setting an illumination focal length of the dynamic illuminator when capturing the cataract images to complement a focal length of the eye such that illumination from the dynamic illuminator is substantially collimated after passing through the crystalline lens and illuminating a retina of the eye.

17. The method of claim 13, further comprising:sequentially adjusting the illumination pattern during the cataract imaging to illuminate the eye from a plurality of different source locations for imaging the cataract from different perspectives during different ones of the cataract images.

18. The method of claim 13, wherein characterizing the cataract based upon the cataract images comprises:fitting a two-dimensional (2D) density function to the cataract imaged in the cataract images, wherein the 2D density function has a variable density over a 2D plane.

19. The method of claim 13, wherein characterizing the cataract based upon the cataract images comprises:grading the cataract based upon the cataract images; ormapping a perimeter shape of the cataract based upon the cataract images.

20. The method of claim 13, further comprising:setting the illumination pattern for retinal imaging, wherein the illumination pattern is narrower for the retinal imaging than the cataract imaging;setting the imaging focal length to focus on a posterior portion of the eye including a retina; andcapturing the retinal images with the illumination pattern narrowed and the imaging focal length set for the retinal imaging.

21. The method of claim 20, further comprising:163960-P485WOselecting one or more illumination patterns for the dynamic illuminator during the retinal imaging based upon the characterizing of the cataract to reduce illumination of the retina passing through the cataract.173960-P485WO

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