OCT zonular imaging

Abstract

A system, method, or apparatus for imaging the anterior segment of the eye includes a non-contact adapter / lens that attaches to an existing ophthalmic imaging system and redirects the imaging system's light beam across the eye's pupil at a steep angle, particularly the steep angle that allows the ophthalmic imaging system to image the zonules below the iris, which are normally blocked by the iris and inaccessible for imaging.

Description

[Technical field]

[0001] The present invention relates generally to optical coherence tomography (OCT) imaging of the anterior portion of the eye, and more particularly to OCT imaging just below the iris, and in particular imaging of the zonules of the eye. [Background technology]

[0002] FIG. 1 shows the anterior portion of eye 11, including cornea 13, anterior chamber 15, iris 17 with a central opening forming pupil 19, lens 21, sclera 27 (white of the eye), and limbus 29 (the boundary between cornea 13 and sclera 27). Also shown in FIG. 1 are zonules 23, which are fibrous structures that hold lens 21 in place and allow accommodation by contraction of the ciliary muscle (or ciliary body) 25. Imaging of zonules can be beneficial not only for disease diagnostic purposes, but also to determine the current state of the zonules (e.g., number, thickness change, integrity, strength, etc.) prior to medical ophthalmic procedures, such as procedures that may perturb lens 21.

[0003] However, imaging of the zonule is complicated because the zonule 23 is located below / behind the iris 17, which blocks the imaging light from reaching the zonule 23 directly. As a result, there is currently no convenient and reliable method to visualize or image the lens zonule 23. This limits the understanding of the anatomical and pathological processes involving the zonule 23, which is important in diseases such as pseudoexfoliation syndrome, pigment dispersion syndrome, Marfan syndrome, Weill-Marchesani syndrome, ectopia lentis, and trauma. Furthermore, due to the lack of zonular imaging, zonular support during cataract surgery cannot be reliably assessed preoperatively. Often, zonular weakness and zonular dialysis (lack of zonular support of the lens capsule, the membrane that surrounds the lens 21) are only recognized intraoperatively during cataract surgery and may surprise the surgeon. The surgeon cannot plan the surgery accordingly, which may lead to complications such as posterior capsule rupture and retained nuclei, which may result in the need for additional surgery or compromise the final surgical outcome.

[0004] Most efforts to date to visualize zonules have centered on ultrasound biomicroscopy (UBM), which uses ultrasound to determine the depth of tissue structures by directly measuring the time delay of returning ultrasound signals. However, UBM cannot be performed by a technician, is time-consuming for the physician, and uncomfortable for the patient. Furthermore, previous histopathological studies have shown that the width of individual zonules typically ranges from 10 to 30 μm, which is below the typical resolution limit of UBM, which is approximately 50 μm.

[0005] Optical coherence tomography (OCT) is an imaging technique that provides higher resolution imaging and is minimally invasive. Although not targeted to zonular imaging, there have been efforts to use OCT to image the anterior segment of the eye at steeper angles than normal. For example, U.S. Patent Nos. 5,233,333 and 5,233,333 (both by Izatt et al.) describe a system for imaging the limbal area of ​​the eye. Izatt et al. use a custom contact lens configured to direct the OCT beam to the limbus 29 of the eye 11. However, this approach requires the OCT system to contact the eye (e.g., the cornea), complicating its use, and furthermore does not provide imaging below the iris. Izatt's approach appears to be aimed at imaging the iridocorneal angle of the anterior chamber. The mismatch in refractive index between air and the anterior segment causes light to refract, making it difficult to direct the beam to measure the iridocorneal angle. Izatt therefore provides a contact lens to add a medium with a similar refractive index between the optics and the cornea. The beam does not refract at the interface, which is evident from the Izatt drawing. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] U.S. Patent No. 9,517,006 [Patent Document 2] U.S. Patent No. 9,936,868 Summary of the Invention [Problem to be solved by the invention]

[0007] It is an object of the present invention to provide a system and method for imaging the front of the eye below the iris at steep angles. Another object of the present invention is to provide an ophthalmic imaging system (e.g., a fundus imager or OCT system) for imaging the anterior region of the eye just below the iris that avoids contact with the eye, e.g., does not contact the cornea or sclera of the eye.

[0008] It is a further object of the present invention to provide a system and method for imaging the zonules of the eye using an ophthalmic imaging system. [Means for solving the problem]

[0009] The above objectives are achieved in a method / system / apparatus that uses or includes a non-contact (contactless) lens adapter (e.g., an ophthalmic "cup") that can be mounted (e.g., coupled or attached) onto an existing ophthalmic imaging system (e.g., a fundus imager and / or an OCT system) to enable direct imaging of the lens zonules. Angular directionality can be achieved by the non-contact (contactless) adapter (or cup). The adapter (or cup) can house one or more transmissive and reflective optical components (e.g., mirrors, retroreflectors, prisms, beam splitters, etc.) for redirecting the light beam. For example, the non-contact adapter can include one or more reflective surfaces that redirect the imaging light beam from the ophthalmic imaging system at a steep angle (e.g., 70 degrees or more relative to the optical center of the imaging system) into the eye to image the area directly below the iris (e.g., the area including the zonules and / or ciliary body). Due to the mismatch in refractive index between air and the front of the eye, the imaging light beam is refracted at the cornea (e.g., as it passes from air through the cornea into the anterior chamber). The steeper angle at the cornea helps to compensate for this refraction, allowing the area just below the iris to be imaged without touching the eye. This contrasts with the approach used, for example, by Izatt, supra. Izatt's approach not only requires a shallower angle (e.g., a less steep angle of incidence) at the cornea to view the edge of the eye above the iris (e.g., the iridocorneal angle), but also requires a custom contact lens with a special medium (in contact with the eye) with a similar refractive index between the optic and the cornea to avoid refraction at the cornea.

[0010] The present zonular imaging system provides sufficient high resolution to accurately assess the health of individual zonular fibers (e.g., including quantification metrics such as density, thickness, length, branching points, number of branches, etc.), which may provide significant diagnostic value (e.g., a structural health number on a predefined health rating scale).

[0011] The non-contact lens (e.g., adapter) of the present invention can include one or more flat mirrors and / or curved mirrors (or a combination of both) to direct the imaging (scanning) beam (e.g., OCT beam) at an optimal angle to target ophthalmic anatomical features at the front of the eye, including the ciliary body under the iris or adjacent to the ciliary body, such as for imaging the zonules. The non-contact lens (adapter) further allows the imaging beam to scan the periphery of the patient's lens while allowing the patient to maintain central fixation. For example, the non-contact lens can provide an unobstructed view (through the non-contact lens) from the field of view (point of view) of the patient's eye so that the patient can maintain central fixation while the non-contact lens allows scanning the periphery of the lens (e.g., the outer edge region of the lens) (e.g., scanning the zonules and ciliary body). Thus, the imaging system can be used to quantify zonules length, thickness, density (e.g., density distribution around the lens periphery), branching characteristics, location and number of contact points between the zonules and the lens and / or capsule, and other tissue characteristics to determine the structural health of the zonules (e.g., value, grade, or rating). For example, different quantified physical features may be assigned a diagnostic rating based on a predefined normative scale, and a weighted sum of the observed ratings of the features may be determined. Based on the resulting weighted sum, an overall diagnostic rating (e.g., excellent, good, fair, poor) may be assigned. Characteristics that have been identified as being more important to determine the ability of the zonules to withstand surgical procedures, such as number of zonules, number of branches, thickness, number of contact points with the ciliary body and / or lens / capsule, may be weighted more heavily than other characteristics.

[0012] The above objects are achieved in an adapter having one or more reflective surfaces for directing a first light beam from an ophthalmic imaging system through the pupil of the eye at an optimal angle selected to target and image the zonules of the eye. The ophthalmic imaging system may be one of a fundus imaging system, an optical coherence tomography (OCT) system, or a combination of both. Preferably, the adapter is separated from and avoids contact with the cornea or sclera of the eye while the zonules are being imaged. Optionally, the eye can maintain central fixation while the first light beam scans around the lens of the eye.

[0013] Optionally, the reflective surface is curved. The reflective surface may be implemented as a first conical surface. The adapter may include a second reflective conical surface concentric with the first conical surface. The second reflective surface may be flat and may be located closer to the optical center of the imaging system than the first reflective surface.

[0014] The reflective surface of the adapter may be off-center, and a central region of the adapter may be configured to allow passage of a second light beam from (e.g., emitted by) an ophthalmic imaging system, which may be a fixation target projected onto the eye and / or a second imaging beam for imaging the eye (e.g., imaging an outer region of the eye, the cornea, or the retina).

[0015] The ophthalmic imaging system may include a computer processor for quantifying one or more tissue characteristics, including one or more of zonular length, zonular thickness, and zonular density. The computer processor may further determine a structural health rating based on the quantified one or more tissue characteristics. For example, the health rating may be a numerical value based on a predetermined numerical scale (e.g., a scale of 1 to 10).

[0016] Other objects and achievements of the present invention, together with a fuller understanding of the invention, will become apparent and appreciated by reference to the following description and claims taken in conjunction with the accompanying drawings.

[0017] To facilitate the understanding of the present invention, several publications may be cited or referenced herein. All publications cited or referenced herein are incorporated by reference in their entirety.

[0018] The embodiments disclosed herein are merely exemplary, and the scope of the disclosure is not limited thereto. Any feature of an embodiment described in one claim category (e.g., system) may also be claimed in other claim categories (e.g., method). Dependencies or back references in the appended claims are selected for formality reasons only. However, subject matter resulting from intentional reference to the preceding claims may also be claimed, and therefore any combination of claims and features thereof may be disclosed and claimed regardless of the dependencies selected in the appended claims.

[0019] In the drawings, like reference symbols / letters refer to like elements. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 shows the anterior part of the eye. [Diagram 2] FIG. 1 illustrates an existing ophthalmic imaging system incorporating an adapter according to the present invention. [Diagram 3] FIG. 1 shows an exemplary OCT image that can be achieved with the present invention. [Figure 4A-4D] FIG. 1 illustrates four exemplary embodiments of the present invention. [Figure 5A-5C] FIG. 5 illustrates an alternative embodiment of the invention in which the non-contact adapter of FIGS. 2-4 incorporates a second (more centrally located) reflective surface that redirects the imaging beam to the first reflective surface. [Figure 6]5A-5C show alternative embodiments in which the first reflective surface of FIGS. 2-5 is implemented as a first conical reflective surface / cup, and the secondary reflective surface of FIGS. 5A-5C is implemented as a second conical reflective surface disposed within the first conical cup. [Figure 7] FIG. 7 provides a conical structure similar to FIG. 6 with an aperture area along the optical center of the ophthalmic imaging system. [Figure 8A-8B] FIG. 5C shows an embodiment similar to that of FIGS. 5A and 5B with the addition of a secondary focusing lens 65 within the non-contact adapter to help focus the second beam or beams, respectively. [Figure 9A-9C] FIG. 1 illustrates an alternative view of an exemplary embodiment of the present invention coupled to an exit aperture of an ophthalmic imaging system. [Figure 10] FIG. 1 illustrates an example of a slit-scan ophthalmic system for imaging the fundus. [Figure 11] 1 illustrates a generalized frequency-domain optical coherence tomography system that may be used to collect 3D image data of the eye suitable for use with the present invention. [Figure 12] An example of an en face vascular image is shown. [Figure 13] 1 illustrates an exemplary computer system (or computing device or computer). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The system provides an unprecedented detailed view of the ophthalmic structures behind the iris. In particular, it can reliably identify the patient's zonular fibers and peri-lens (peripheral area of ​​the lens) anatomy and any pathology. The system has been shown to be fast and effective while avoiding direct contact with the patient's eye (e.g., no contact with the cornea or sclera). Certain embodiments are optimized to be easily adapted to existing ophthalmic imaging systems and easily used by those trained to use these existing ophthalmic imaging systems. Thus, the present invention can be incorporated with minimal effort into current cataract and anterior eye ophthalmic practice.

[0022] For illustrative purposes, FIG. 2 shows a representation of an existing ophthalmic imaging system 12, such as a fundus imager or optical coherence tomography (OCT) system, incorporating an adapter 41 according to the present invention. Fundus imagers typically capture two-dimensional (2D) planar images of the fundus (e.g., retina). OCT systems can generate 2D or three-dimensional (3D) images of subcutaneous tissues, such as the various tissue layers of the retina. OCT systems may generate images of the anterior portion of the eye, such as the cornea, or the posterior portion of the eye, such as the retina. OCT angiography may provide images of the retinal vasculature (blood flow), and anterior segment OCT (AS-OCT) may be specialized to image the anterior region of the eye using an add-on adapter. A more detailed description of various exemplary ophthalmic imaging systems suitable for use with the present invention is provided below with reference to FIGS. 10-13.

[0023] In any event, a typical ophthalmic imaging system generally has an aperture 14 through which an imaging beam (or imaging light) 16 emerges to image the eye. The imaging beam generally has a limited angular range that limits the field of view of the ophthalmic imaging system. Additionally, various anatomical features of the eye, such as the iris, are impervious to the imaging beam 16 (as indicated by the bouncing arrow 16a), thus limiting what portions of the eye can be imaged. For example, an OCT imaging beam cannot penetrate the iris 17 to reach and image the anatomical structures covered by the iris. To overcome this limitation, the present invention increases the angle of incidence (e.g., the angle relative to the optical center (or optical axis) 47 of the ophthalmic imaging system 12) of the imaging (light) beam 43 so that it enters the pupil 19 of the eye at a steeper angle to reach the front of the eye just below the iris that was previously inaccessible. For example, the present non-contact adapter 41 can be used to expand the capabilities of the ophthalmic imaging system 12 to image the zonules, which was previously not practical. Although not shown for ease of illustration, it should be understood that imaging beam 43 refracts at the cornea due to the refractive index mismatch between the air and the front interface. Thus, imaging beam 43 may be incident at a steeper angle (e.g., greater than 70°) at the cornea than at the pupil to account for refraction at the interface, yet still have a steep enough angle at the pupil to image just below the iris.

[0024] This increase in the incidence angle can be achieved by modifying the internal optics of the ophthalmic imaging system, but currently it is preferable to avoid such modifications. Instead, some embodiments of the present invention provide an adapter (e.g., a non-contact lens adapter) that can be attached (coupled) to the ophthalmic imaging system 12 and redirect the imaging beam 16 from its normal exit aperture 14 to an axially offset and angled aperture 41' to generate a steep imaging beam 43. Optionally, if the ophthalmic imaging system is already of a type that is configured to accept an existing aperture adapter, such as AS-OCT, the present non-contact adapter 41 can be configured to have a similar coupling mechanism to the existing aperture adapter of the ophthalmic imaging system so that it is interchangeable with the existing aperture adapter of the ophthalmic imaging system. Alternatively, the non-contact adapter of the present invention can be made to have a special coupling mechanism configured to couple to a specific ophthalmic imaging system.

[0025] FIG. 3 shows an exemplary OCT image 31 that can be achieved with the present invention. The integrity and stability of the zonular fibers are important factors in the outcome of cataract surgery. Preoperative visualization of such structures is difficult due to the structures being located behind the iris, which blocks light and prevents scattering. For illustrative purposes, a dashed square 39 shows a schematic outline of a portion of a schematic eye 11 that may correspond to a portion of an actual eye as shown in image 31. An exemplary imaging optical beam (or imaging light beam) 43, such as from an OCT system, is shown entering the cornea 13 at a steep angle (e.g., about 70°), refracting at the cornea 13 due to the refractive index mismatch between air and the front of the eye, continuing through the pupil 19, and imaging the lower region of the zonule 23 (and / or ciliary body 25) below the iris 17. The embodiment(s) can reliably image the anatomical location of the lens periphery (e.g., the peripheral region of the lens 21, including the lens capsule or lens capsule 21' that encases the lens 21), the anterior vitreous 33, and the posterior zonules 23'. The present approach is capable of resolving individual zonular fibers 35 in the image 31. It should be appreciated that the upper portions 23'' of the zonules 23 can be imaged by projecting the imaging optical beam 43 at a steeper angle (e.g., by forming a shallow (small) angle 9 below the iris 17 with respect to a horizontal reference line (at the iris) perpendicular to the optical axis).

[0026] A clinical study was conducted to evaluate the feasibility of zonular imaging using swept-source ophthalmic coherence tomography (SS-OCT). To image the anterior segment of the eye, a PLEX Elite® 9000 (ZEISS®, Dublin, CA, USA) SS-OCT was modified with an external add-on lens (e.g., Adapter 41 in Figure 2) (+20 diopter). Healthy subjects were recruited and extended for this study. Zonular structures were imaged using a 4.5x1.5mm scan pattern capturing 300 A-scans in one B-scan frame. Each B-scan was repeated, recorded, and averaged 10 times to reduce speckle noise. There were a total of 51 B-scans in the cube. Eye movement tracking was disabled in this study, but to minimize movement artifacts, the scan pattern was designed to acquire all data in less than 2 seconds. Five subjects (ages ranging from 18 to 65 years) were successfully imaged. The steep incision angle allowed the incoming light to pass through the lens 21 and reach a portion of the zonular cluster 23, avoiding blockage from the iris 17. This preliminary imaging technique allowed imaging of approximately half the length of the zonular cluster. Additionally, a strong signal was identified just posterior to the lens capsule 21', which may represent the anterior vitreous surface of the vitreous. The present invention provides the first demonstration of imaging of the zonular structure and anterior vitreous using SS-OCT. The advantages of this system are that it provides an unprecedented detailed view of the structures behind the iris, helping to identify the anatomy of the zonular fibers, lens periphery, and anterior vitreous in patients, facilitating surgical planning.

[0027] Thus, the present invention provides a view of the anatomy behind the iris and can reliably identify the patient's zonular fibers and peripheral lens anatomy and any pathology. Furthermore, the present invention is fast and easy to use because it avoids direct contact with the patient's eye (e.g., cornea and / or sclera). As described in more detail below, the present invention can be incorporated into existing ophthalmic imaging systems. Thus, the system can be easily used by technicians who are already trained to use existing ophthalmic imaging systems with little to no additional training. As a result, the present invention can be integrated into existing cataract and anterior segment ophthalmic practices, thus providing new and important diagnostic information with minimal interruption to existing medical practice procedures.

[0028] For example, anterior segment optical coherence tomography (AS-OCT) may already use a specialized lens system that is removable. The present invention can be incorporated into an adapter (or "OCT eyecup") that provides another specialized lens system that can be interchanged with the existing AS-OCT lens system.

[0029] An exemplary field in which the present invention may find immediate utility is in the field of cataract surgery and intraocular lens implantation. The success of such surgical procedures is linked to the physical state of the patient's zonule, but traditionally it has not been possible to easily observe / identify the state of the patient's zonule before or after surgery. The present invention allows for direct 3D imaging of the zonule using AS-OCT with the present special lens adapter, making it possible to diagnose and help manage zonular weakness and / or (zonal) dehiscence in the setting of cataract surgery. The present invention may also be used to help determine the correct power of an intraocular lens (IOL) to be implanted during cataract surgery to achieve an ideal refractive outcome. The present invention may also be used to diagnose and help manage zonular weakening and / or dehiscence after cataract surgery. The system also allows for diagnosing subluxation or dislocation of the lens or IOL, as well as diagnosing the following conditions: trauma, prior surgery, advanced age, exfoliation syndrome, pigment dispersion syndrome, Marfan syndrome, Ehler-Danlos syndrome, Weill-Marchesani syndrome, homocysteinuria, aniridia, ectopia lentis, ectopic lens-ectopic pupil, ciliary body coloboma, and / or zonulopathy, which may be associated with hypermature cataract. The invention may also be used to diagnose the conditions of IOL misplacement (extracapsular), uveitis-glaucoma-hyphema (UGH) syndrome, ciliary body tumors, and iris epithelial cysts and posterior iris tumors. Diagnosis can be made by a trained professional through visual inspection of the captured images, or by computerized systems utilizing quantification indices and normative measures of various pathologies and / or machine learning techniques such as decision trees, linear regression, support vector machines (SVM), or neural networks trained to recognize the above diagnoses based on images using the present imaging technology.

[0030] 4A-4D show four exemplary embodiments of the present invention. With reference to FIG. 4A, the present invention may include a non-contact adapter (non-contact or contactless lens) 41 (optionally a radial (e.g., circular) adapter and / or a radially symmetric adapter) such as an "OCT / imaging eyecup" for use with an ophthalmic imaging system 40 (such as an OCT, OCTA, fundus imager, or combination thereof) to illuminate and image anatomical features of the eye that are normally obscured by the iris (such as the ocular zonules) and may be located in the anterior (e.g., circumferential) region of the eye (e.g., immediately behind the iris). For illustrative purposes, the ophthalmic imaging system 40 is shown with a dotted arrow, as is an ophthalmic (or ophthalmic) lens OL of the ophthalmic imaging system 40. Typically, the ophthalmic lens OL is the lens of the ophthalmic imaging system 40 that is closest to the patient's eye E and through which the imaging beam (e.g., scanning beam) 43 of the system exits the ophthalmic imaging system 40 and enters the eye E. The ophthalmic lens OL may focus the imaging beam 43 on the object being imaged, typically directing the imaging beam 43 along the optical center 47 of the ophthalmic imaging system 40 to image the rear of the eye E (e.g., fundus / retina F). However, in this example, the imaging beam 43 is made to scan the peripheral region of the ophthalmic lens OL, and the adapter (non-contact lens) 41 redirects this peripheral imaging beam 43 at a steep angle through the pupil of the eye to the front of the eye E. The adapter 41 may have curved and / or angled reflective surface(s) 45 that direct the imaging beam 43 (e.g., direct the imaging optical path of the ophthalmic imaging system) at a high angle relative to the optical center 47 of the imaging system. For example, when imaging the zonules, the adapter 41 can direct the imaging beam 43 at an angle of about 70 degrees or more from the optical center 47 to enter the eye E and reach the zonules of the eye without being clipped / blocked by the iris of the eye.The reflective surface 45 may be one continuous curved surface along the inner circumference of the adapter 41, or one or more separate (flat or curved) reflective surfaces (e.g., mirror surfaces) positioned at predetermined positions and angles within the inner circumference of the adapter 41 to direct the imaging optical path of the ophthalmic imaging system to a predetermined location along the front of the eye E. The reflective surface 45 may be a peripherally curved reflective surface in a conic section shape with a curvature along the z-axis 47 (e.g., the optical center of the imaging system). The curvature of the reflective surface 45 may function to form a focal point at the same distance from the reflective surface 45 on both translational axes (e.g., the x-axis and the y-axis), thus preventing (or mitigating) illumination and imaging astigmatism. In one embodiment, the ophthalmic lens OL may use a single curved mirror 45 to direct the imaging beam 43, which, in combination with a custom scan pattern, allows the ophthalmic imaging system 40 to image 360 ​​degrees around the crystalline lens of the eye E, thereby allowing all zonules to be captured in one shot. Alternatively, multiple acquisitions (e.g., multiple scanning operations) can be used to scan the superior, inferior, nasal, and / or temporal sides, respectively, using several mirror surfaces 45. The reflective surfaces 45 can be a single mirror at each location, or multiple mirrors per quadrant, each featuring a slightly different angle of reflection to account for (e.g., small) anatomical differences between subjects (e.g., patients).

[0031] In order for the imaging system of FIG. 4A to properly image the posterior portion of the eye E through the central region of the ophthalmic lens OL and the anterior portion of the eye E through the peripheral region of the ophthalmic lens OL and the reflective surface 45, the focal length of the ophthalmic imaging system 40 can be sufficiently long to focus on objects in the anterior region of the eye (e.g., the zonules) and objects in the posterior region of the eye (e.g., the fundus / retina region F).

[0032] As shown in FIG. 4B, if the ophthalmic imaging system 40 is optimized to focus on the back of the eye and it is difficult to focus on the anterior region of the eye, the adapter 41 may incorporate a central lens 49 to help focus the imaging beam 43 of the system on the desired anterior region of the eye (e.g., on the zonules). As described above with reference to FIG. 4A, the reflective surface 45 of FIG. 4B may be a peripherally curved reflective surface with a conic section shape having a curvature along the z-axis, and the curvature of the reflective surface 45 may function to form a focal point at the same distance from the reflective surface 45 on both translational axes to prevent illumination and imaging astigmatism. Optionally, the outer region (e.g., peripheral region) of the central lens 49 (e.g., the portion of the central lens through which the imaging beam 43 of the system passes to image the zonules) may be used in conjunction with the reflective surface 45 (which may be, for example, a conical mirror) to correct aberrations, if necessary. In this configuration, the imaging system may be used to image the anterior or posterior regions of the eye separately. For example, when imaging the fundus / retina F, the adapter 41 can be removed from the ophthalmic imaging system 40 and the imaging system can be used to directly image the retina F of the eye E. When imaging the zonules, or other anterior features of the eye that are normally obscured / blocked by the iris, the adapter 41 is placed (e.g., attached) on the ophthalmic imaging system 40 to increase the angle of incidence of the imaging beam 43 at the pupil. Instead of selectively removing the adapter 41 when it is desired to image the posterior portion of the eye, it is conceivable to remove (or make substantially transparent) a central region of the central lens 49 so that it does not interfere with the imaging beam 43 of the system when imaging the posterior portion of the eye along the optical center 47 of the system. In this way, the adapter 41 can be fixed to the imaging system 40 without having to be selectively removed or replaced depending on the anterior or posterior portion of the eye being imaged.

[0033] FIG. 4C provides an alternative configuration that allows for simultaneous focusing on both the front and back of the eye. In this example, the peripheral region 49p of the central lens 49 functions in a similar manner as in FIG. 4B and serves to focus the imaging beam 43 of the system on the front of the eye. However, it may be desirable to simultaneously have a second beam 44 that can be focused on the back of the eye (e.g., the fundus F) (and optionally scanned transversely to the back of the eye), such as by having an inner region 49i of the central lens 49 configured to focus the second beam 44 on the back of the eye. This may be the case when it is desired to image the fundus F (such as by a scanning laser ophthalmoscope, SLO, or other fundus imaging system) simultaneously with imaging the zonula of the eye (e.g., by using an OCT system). In this case, the image from the SLO may be used to generate motion tracking information by comparing the currently captured image to a previous reference image. The motion tracking information may be used in post-processing for motion correction of the system imaging beam 43 and / or motion aberration correction of images acquired by the system imaging beam 43. Alternatively or additionally, it may be desirable to project a fixation target through the interior region 49i of the central lens 49 to direct the patient's gaze while the front of the eye (e.g., the zonules) is being imaged. For example, it has been found that when imaging from the nasal direction, a person's nose may obstruct the imaging beam 43, and this obstruction may be reduced by moving the patient's gaze away from the nose (e.g., moving the patient's pupils away from the nose). For example, the fixation target may be used to guide the patient to gaze away from the nose when imaging the lateral zonules of the eye furthest from the nose. Thus, the interior region 49i may be configured to provide fixation via a beam splitter (preferably a dichroic beam splitter) for retinal imaging (which may provide motion tracking) or both fixation and retinal imaging simultaneously.

[0034] 4D is yet another embodiment, in which, as described above, an interior region of the central lens 49 may be removed or made transparent so as not to interfere with the light path along the optical center of the imaging system. In this example, the peripheral region 49p functions to help focus the imaging beam 43 to the front of the eye, and the open interior region of the central lens 49 allows the secondary beam 44 to pass unobstructed to the rear of the eye E. As described above, the secondary beam 44 may be one or more secondary beams, including a fixation beam for providing a fixation target, a second imaging beam for providing a secondary fundus imaging function (such as for motion tracking), or both.

[0035] 5A, 5B, and 5C show an alternative embodiment of the invention in which the non-contact adapter 41 of FIGS. 2-4 incorporates a second reflective surface 61 that redirects the imaging beam 43 to the angled reflective surface(s) 45 mentioned above. The use of the secondary reflective surface 61 allows the imaging beam 43 to be directed to be incident on the eye at a desired steep angle. In the embodiment of FIG. 5A, the reflective surface 45 is implemented as a discrete reflective surface (i.e., a mirror) positioned to reflect the imaging beam from the secondary reflective surface 61 and the eye. As shown, the imaging beam 43 may be scanned across the reflective surfaces 61 and 45 to be scanned across a target area of ​​the eye E. In this case, the area of ​​the eye E that is scanned is the area furthest from the reflective surface 45. FIG. 5B shows the repositioning of the reflective surfaces 61 and 45 to scan (e.g., image) another anterior area of ​​the eye E. The reflecting surface 61 may be rotated around the z-axis to face in different directions, and the reflecting surface 45 may be repositioned (e.g., moved to a different position or to have multiple reflecting surfaces 45 at the required scanning position) to scan the eye E from different directions. In this example, the imaging beam 43 is scanned at different peripheral regions of the central lens 49 and the ophthalmic lens OL. Alternatively, as shown in FIG. 5C, the secondary reflecting surface 61 may be avoided from rotating around the z-axis by receiving the imaging beam 43 at the opposite surface (from FIG. 5A) and laterally shifting the position and / or changing its angle to change the direction of the imaging beam 43 to a direction different from that of FIG. 5A. In this way, multiple opposing sides of the anterior region of the eye E may be scanned while maintaining the scanning of the imaging beam 43 at a single region of the central lens 49 and the ophthalmic lens OL.

[0036] FIG. 6 shows an alternative embodiment in which the angled reflective surface 45 of FIGS. 2-5 is implemented as a cone-shaped cup 45′ and the secondary reflective surface 61 of FIGS. 5A-5C is replaced by a secondary conical reflective surface 61′ disposed (e.g., concentrically) within the conical cup 45′. The conical cup 45′ may be open on both sides or a central lens 49 may be fixed to the opening of the conical cup 45′. In this configuration, a 360-degree image of the front of the eye E may be generated by scanning the imaging beam 43 around the periphery of the ophthalmic lens OL and the central lens 49. However, this configuration may complicate imaging of the eye E along the optical center 47 of the ophthalmic imaging system due to interference by the secondary conical reflective surface 61′. Thus, if the front of the eye E is not imaged at a steep imaging angle, the non-contact adapter 41 may be removed from the ophthalmic imaging system.

[0037] FIG. 7 provides a similar conical structure to FIG. 6, but with an opening region 63 along the optical center 47 of the ophthalmic imaging system, as in FIG. 4D (or with a clear lens or an additional central lens to aid focusing, as in FIG. 4C), to enable imaging of the anterior and posterior regions of the eye E without requiring removal of the non-contact adapter 41. In this example, both the outer reflective surface 45'' and the inner secondary reflective surface 61'' can be implemented as open cones. As explained above, this configuration also enables simultaneous imaging of the anterior and posterior regions of the eye E by using secondary imaging beams, as shown in FIGS. 4C and 4D.

[0038] 8A and 8B show an embodiment similar to that of FIGS. 5A and 5B, respectively, with the addition of a secondary focus lens 65 in the non-contact adapter 41 to help focus one or more second beams 44 in a manner similar to the inner region 49i of FIG. 4C. As described above, the second beams 44 can provide a fixation point and / or a secondary imaging function (e.g., retinal imaging), which can optionally be used for motion tracking (e.g., motion correction). As shown, the optics of the non-contact adapter 41 can include a plane mirror to redirect the obliquely scanned beam to the eye at an angle of 70°. Also, lenses can be included to adjust the anterior vergence and numerical aperture (i.e., spot size). To cover 360°, a parabolic or aspheric mirror (or other reflective surface) can be used, as shown in FIGS. 4A, 4B, 4C, 4D, 6, and 7. Optionally, the optics can be optimized to remove the astigmatism added by the parabolic mirror.

[0039] 9A, 9B, and 9C show alternative views of an exemplary embodiment of the present invention coupled to an exit aperture 14 of an ophthalmic imaging system. FIG. 9A shows a partial cutaway view of a non-contact adapter / lens 41 according to the present invention attached to an exit aperture 14 of an ophthalmic imaging system. In this example, the non-contact adapter 41 extends from the aperture 14 to image the eye E providing an imaging beam 43 at a steep angle. FIG. 9B shows a covered view of the aperture 14 of FIG. 9A coupled to the non-contact adapter 41. FIG. 9C provides a top view of a non-contact adapter 41 according to the present invention used to image the anterior portion of the eye of a right eye (not shown) of a patient 67. The non-contact adapter 41 is shown coupled to the aperture 14 positioned in front of the patient's right eye between the patient's nose 68 and eyebrow 69.

[0040] Various hardware and architectures suitable for the present invention are described below. Fundus Imaging System Two categories of imaging systems used to image the fundus are flood-illumination imaging systems (or flood-illumination imagers) and scanning-illumination imaging systems (or scanning imagers). A flood-illumination imager simultaneously floods the entire field of view (FOV) of interest of the object with light, such as by using a flash lamp, and captures a full-frame image of the object (e.g., fundus) with a full-frame camera (e.g., a camera having a two-dimensional (2D) photosensor array sized collectively to capture the desired FOV). For example, a flood-illumination fundus imager floods the fundus of the eye with light and captures a full-frame image of the fundus in a single image capture sequence of the camera. A scanning imager provides a scanning beam that is scanned across the object, e.g., the eye, and the scanning beam is imaged at different scanning positions as the scanning beam is scanned across the object to create a series of image segments that can be reconfigured, e.g., combined, to create a composite image of the desired FOV. The scanning beam can be a point, a line, or a two-dimensional region such as a slit or a wide line.

[0041] FIG. 10 illustrates an example of a slit-scanning ophthalmic system SLO-1 for imaging the fundus F, which is the inner surface of the eye E opposite the eye lens (or crystalline lens) CL and may include the retina, optic disc, macula, fovea, and posterior pole. In this example, the imaging system is in a so-called "scan-descan" configuration, in which the scanning line beam SB traverses the optical components of the eye E (including the cornea Crn, iris Irs, pupil Ppl, and crystalline lens) so as to be scanned across the entire fundus F. In the case of a floodlight fundus imaging device, no scanner is required and light is irradiated over the entire desired field of view (FOV) at one time. Other scanning configurations are known in the art, and the specific scanning configuration is not critical to the present invention. As shown, the imaging system includes one or more light sources LtSrc, preferably a multi-color LED system or a laser system with a suitably adjusted etendue. An optional slit Slt (adjustable or stationary) may be positioned in front of the light source LtSrc and used to adjust the width of the scanning line beam SB. Additionally, the slit Slt can remain stationary during imaging or can be adjusted to different widths to allow different confocal levels and different applications for a particular scan or during scanning used for reflection suppression. An optional objective lens ObjL can be placed in front of the slit Slt. The objective lens ObjL can be any one of the state-of-the-art lenses, including but not limited to refractive, diffractive, reflective, or hybrid lenses / systems. The light from the slit Slt passes through a pupil splitting mirror SM and is directed to the scanner LnScn. It is desirable to bring the scanning plane and the pupil plane as close as possible to reduce vignetting of the system. An optional optical system DL can be included to manipulate the optical distance between the images of the two components. The pupil splitting mirror SM can pass the illumination beam from the light source LtSrc to the scanner LnScn and reflect the detection beam from the scanner LnScn (e.g., the reflected light back from the eye E) towards the camera Cmr. The task of the pupil splitting mirror SM is to split the illumination beam and the detection beam and to help suppress system reflections.Scanner LnScn can be a rotating galvo scanner or other type of scanner (e.g., piezoelectric or voice coil, microelectromechanical system (MEMS) scanner, electro-optic deflector, and / or rotating polygon scanner). Depending on whether pupil splitting occurs before or after scanner LnScn, the scan can be split into two steps with one scanner in the illumination path and a separate scanner in the detection path. Particular pupil splitting arrangements are described in detail in U.S. Pat. No. 9,456,746, the entirety of which is incorporated herein by reference.

[0042] From the scanner LnScn, the illumination beam passes through one or more optical systems, in this case a scan lens SL and an ophthalmic or ocular lens OL, that allow the pupil of the eye E to be imaged into the image pupil of the system. In general, the scan lens SL receives the scanning illumination beam from the scanner LnScn at any of a number of scan angles (angles of incidence) and generates a scan line beam SB with a substantially planar focal plane (e.g., a collimated optical path). The ophthalmic lens OL then focuses the scan line beam SB on the imaging object. In this example, the ophthalmic lens OL focuses the scan line beam SB on the fundus F (or retina) of the eye E to image the fundus. In this way, the scan line beam SB creates a transverse scan line that moves across the fundus F. One possible configuration of these optical systems is a Keplerian telescope, where the distance between the two lenses is selected to generate an intermediate fundus image that is approximately telecentric (4-f configuration). The ophthalmic lens OL can be a single lens, an achromatic lens, or an arrangement of different lenses. All lenses can be refractive, diffractive, reflective, or hybrid, as known to those skilled in the art. The size and / or shape of the ophthalmic lens OL, the focal length of the scanning lens SL, the pupil splitting mirror SM, and the scanner LnScn can vary depending on the desired field of view (FOV), so that arrangements can be envisioned in which multiple components can be switched in and out of the beam path, for example by using a flip of the optical system, a motorized wheel, or removable optical elements, depending on the field of view. The pupil splitting can also be changed to accommodate the change in FOV, since a change in field of view results in a different beam size on the pupil. For example, a field of view of 45° to 60° is a typical or standard FOV for a fundus camera. A higher field of view, for example a wide field of view FOV of 60° to 120° or more, may also be feasible. A wide field of view FOV may be desirable for the combination of the wide line fundus imager (BLFI) with another imaging modality, such as optical coherence tomography (OCT). The upper limit of the field of view may be determined by the accessible working distance combined with the physiological conditions around the human eye. Since a typical human retina has an FOV of 140° horizontally and 80°-100° vertically, it may be desirable to have an asymmetric field of view with as high an FVO as possible on the system.

[0043] The scanning beam SB passes through the pupil Ppl of the eye E and is directed to the retina or fundus, i.e. surface F. The scanner LnScn1 adjusts the position of the light on the retina or fundus F so that a range of lateral positions of the eye E is illuminated. The reflected or scattered light (or emitted light in case of fluorescence imaging) is directed along a similar path as the illumination, defining a focused beam CB on a detection path to the camera Cmr.

[0044] In the "scan-descan" configuration of the exemplary slit-scanning ophthalmic system SLO-1 of the present invention, the light returning from the eye E is "descanned" by the scanner LnScn on the way to the pupil splitting mirror SM. That is, the scanner LnScn scans the illumination beam SB from the pupil splitting mirror SM to define a scanning illumination beam SB across the eye E, but since the scanner LnScn also receives the returning light from the eye E at the same scanning position, it has the effect of descanning the returning light (e.g., canceling the scanning motion) to define a non-scanning (e.g., stationary) focused beam from the scanner LnScn to the pupil splitting mirror SM, which folds the focused beam towards the camera Cmr. At the pupil splitting mirror SM, the reflected light (or emitted light in the case of fluorescence imaging) is separated from the illumination light onto a detection path that is directed to the camera Cmr, which may be a digital camera with a photosensor to capture an image. An imaging (e.g., objective lens) lens ImgL may be positioned in the detection path such that the fundus is imaged onto the camera Cmr. As in the case of the objective lens ObjL, the imaging lens ImgL can be any type of lens known in the art (e.g., refractive, diffractive, reflective or hybrid lens). Additional operational details, in particular methods for reducing artifacts in images, are described in WO 2016 / 124644, the entire contents of which are incorporated herein by reference. The camera Cmr captures the received images and, for example, creates an image file, which can be further processed by one or more (electronic) processors or computing devices (e.g., the computer system of FIG. 13). Thus, focused beams (returned from all scanning positions of the scanning line beam SB) are collected by the camera Cmr, and a full frame image Img can be constructed, such as by montage, from a combination of the individually captured focused beams. However, other scanning configurations are also envisaged, including those in which the illumination beam is scanned across the eye E and the focused beam is scanned across the optical sensor array of the camera.WO 2012 / 059236 and U.S. Patent Application Publication No. 2015 / 0131050, which are incorporated herein by reference, describe several embodiments of scanning slit ophthalmoscopes, including various designs in which the returning light is swept across the camera's photosensor array, designs in which the returning light is not swept across the camera's photosensor array, and the like.

[0045] In this example, the camera Cmr is connected to a processor (e.g., processing module) Proc and a display (e.g., display module, computer screen, electronic screen, etc.) Dspl, both of which may be part of the imaging system itself or may be part of separate, dedicated processing and / or display units, such as a computer system, where data is passed from the camera Cmr to the computer system via a cable or computer network, including a wireless network. The display and processor may be an integrated unit. The display may be a traditional electronic display / screen or may be of the touch screen type and may include a user interface for displaying information to and receiving information from the equipment operator or user. The user may interact with the display using any type of user input device as known in the art, including but not limited to a mouse, knob, button, pointer, and touch screen.

[0046] It may be desirable for the patient's gaze to remain fixed while imaging is performed. One way to achieve gaze fixation is to provide a fixation target to which the patient can be instructed to look. The fixation target can be internal or external to the device depending on which area of ​​the eye is imaged. One embodiment of an internal fixation target is shown in FIG. 10. In addition to the primary light source LtSrc used for imaging, an optional second light source FxLtSrc, such as one or more LEDs, can be positioned such that a light pattern is imaged onto the retina using a lens FxL, a scanning element FxScn and a reflector / mirror FxM. The fixation scanner FxScn can move the position of the light pattern, and the reflector FxM directs the light pattern from the fixation scanner FxScn to the fundus F of the eye E. Preferably, the fixation scanner FxScn is positioned such that it is located in the pupil plane of the system so that the light pattern on the retina / fundus can be moved according to the desired fixation position.

[0047] The slit-scanning ophthalmology system can operate in different imaging modes depending on the light source and wavelength-selective filtering elements used. True color reflectance imaging (similar to that observed by clinicians when examining the eye using a handheld or slit-lamp ophthalmoscope) can be achieved when imaging the eye with a series of colored LEDs (red, blue, green). Images of each color can be built up stepwise with each LED turned on at each scanning position, or each color image can be taken completely separately. The three color images can be combined to display a true color image, or displayed individually to highlight different features of the retina. The red channel best highlights the choroid, the green channel highlights the retina, and the blue channel highlights the pre-retinal layers. Additionally, specific frequencies of light (e.g., individual colored LEDs or lasers) can be used to excite different fluorophores (e.g., autofluorescence) in the eye, and the resulting fluorescence can be detected by filtering out the excitation wavelengths.

[0048] Fundus imaging systems can also provide infrared reflectance images, such as by using an infrared laser (or other infrared light source). Infrared (IR) mode is advantageous in that the eye is not sensitive to IR wavelengths. This infrared (IR) mode may allow the user to continuously take images without disturbing the eye (e.g., in preview / alignment mode) to assist the user during alignment of the instrument. IR wavelengths may also have high penetration through tissue and provide improved visualization of choroidal structures. In addition, fluorescein angiography (FA) and indocyanine green (ICG) angiography imaging can be accomplished by collecting images after a fluorescent dye is injected into the subject's bloodstream. For example, with FA (and / or ICG), a series of time-lapse images may be captured after a photoreactive dye (e.g., a fluorescent dye) is injected into the subject's bloodstream. It should be noted that caution is advised as fluorescent dyes can cause life-threatening allergic reactions in some individuals. High-contrast grayscale images are captured using specific light frequencies selected to excite the dye. As the dye flows through the eye, different parts of the eye glow brightly (e.g., fluoresce), allowing the viewer to see how the dye, and therefore blood, is progressing through the eye.

[0049] Optical coherence tomography system In addition to fundus photography, fundus autofluorescence (FA), and fundus fluorescein angiography (FA), ophthalmic images may be produced by other imaging modalities, such as optical coherence tomography (OCT), OCT fundus angiography (OCTA), and / or ocular echography. The present invention, or at least a portion of the present invention, may also be applied to these other ophthalmic imaging modalities with minor modifications as understood in the art. More specifically, the present invention may also be applied to ophthalmic images generated by OCT / OCTA systems that generate OCT and / or OCTA images. For example, the present invention may also be applied to en face OCT / OCTA images. Examples of fundus images are provided in U.S. Patent Nos. 8,967,806 and 8,998,411, examples of OCT systems are provided in U.S. Patent Nos. 6,741,359 and 9,706,915, and examples of OCTA imaging systems may be found in U.S. Patent Nos. 9,700,206 and 9,759,544, all of which are incorporated herein by reference in their entireties. For the sake of completeness, examples of exemplary OCT / OCTA systems are provided herein.

[0050] FIG. 11 illustrates a generalized frequency domain optical coherence tomography (FD-OCT) system for ocular 3D image data collection suitable for use with the present invention. The FD-OCT system OCT_1 includes a light source LtSrc1. Typical light sources include, but are not limited to, broadband light sources with short temporal coherence length, or swept laser sources. A beam of light from the light source LtScr1 is typically guided by an optical fiber Fbr1 to illuminate a sample, for example, an eye E, a typical sample being human intraocular tissue. The light source LrSrc1 can be, for example, a broadband light source with short temporal coherence length in the case of spectral domain OCT (SD-OCT), or a wavelength-tunable laser source in the case of swept-source OCT (SS-OCT). The light is typically scanned with a scanner Scnr1 between the output of the optical fiber Fbr1 and the sample E, so that the light beam (dashed line Bm) is scanned laterally over the area of ​​the sample to be imaged. The light beam from the scanner Scnr1 can pass through a scan lens SL and an ophthalmic lens OL and be focused on a sample E to be imaged. This example shows a scan beam that needs to be scanned in two lateral directions (e.g., x- and y-directions on a Cartesian plane) to scan a desired field of view (FOV). This example is a point-field OCT that uses a point-field beam to scan across the sample. Thus, the scanner Scnr1 is exemplarily shown to include two sub-scanners, a first sub-scanner Xscn for scanning the point-field beam across the sample in a first direction (e.g., horizontal x-direction) and a second sub-scanner Yscn for scanning the point-field beam on the sample in a transverse second direction (e.g., vertical y-direction). If the scan beam is a line-field beam (e.g., line-field OCT) that can sample an entire line portion of the sample at one time, only one scanner may be required to scan the line-field beam across the desired FOV if the entire line portion of the sample can be sampled at one time.If the scanning beam is a full-field beam (eg, full-field OCT), no scanner is required and the full-field light beam may be applied to the entire desired FOV at once.

[0051] Regardless of the type of beam used, light scattered from the sample (e.g., sample light) is collected. In this example, the scattered light returning from the sample is collected into the same optical fiber Fbr1 used to route the light for illumination. The reference light, originating from the same light source LtSrc1, travels along a different path, which in this case includes an optical fiber Fbr2 and a retroreflector RR1 with an adjustable optical delay. As will be appreciated by those skilled in the art, a transmissive reference path can also be used, and an adjustable delay can be placed in the sample or reference arm of the interferometer. The collected sample light is combined with the reference light, for example, at a fiber coupler Cplr1, to form optical interference in the OCT photodetector Dtctr1 (e.g., a photodetector array, digital camera, etc.). Although one fiber port is shown reaching the detector Dtctr1, as will be appreciated by those skilled in the art, various designs of interferometers can be used for balanced or unbalanced detection of the interference signal. The output from the detector Dtctr1 is fed to a processor (e.g., an internal or external computing device) Cmpl, which converts the observed interference into sample depth information. The depth information may be stored in a memory associated with the processor Cmp1 and / or displayed on a display (e.g., computer / electronic display / screen) Scn1. The processing and storage functions may be located within the OCT instrument, or the functions may be offloaded onto (or performed on) an external processor (e.g., an external computing device) to which the collected data may be transferred. An example of a computing device (or computer system) is shown in FIG. 13. This unit may be dedicated to data processing or may perform other tasks that are quite general and not dedicated to the OCT instrument.The processor (computing device) Cmp1 may include, for example, a field programmable gate array (FPGA), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a graphics processing unit (GPU), a system on a chip (SoC), a central processing unit (CPU), a general purpose graphics processing unit (GPGPU), or combinations thereof, that may perform some or all of the processing steps in serial and / or parallel using one or more host processors and / or one or more external computing devices.

[0052] The sample and reference arms in the interferometer can be constructed of bulk optics, fiber optics, or hybrid bulk optics systems and can have different architectures, such as Michelson, Mach-Zehnder, or common path designs, as known to those skilled in the art. Light beam, as used herein, should be interpreted as any carefully directed optical path. Instead of mechanically scanning the beam, a light field can illuminate a one- or two-dimensional area of ​​the retina to generate OCT data (see, e.g., U.S. Pat. No. 9,332,902; D. Hillmann et al., "Holoscopy-holographic optical coherence tomography," Optics Letters, vol. 36(13), p. 2290, 2011; Y. Nakamura et al., "High-Speed ​​three dimensional human retinal imaging by line field spectral domain optical coherence tomography," Optics Express, vol. 20(1), pp. 111-115, 2012). Express, 15(12), 7103, 2007; Blazkiewicz et al., Signal-to-noise ratio study of full-field Fourier-domain optical coherence tomography, Applied Optics, 44(36), 7722, 2005. In time-domain systems, the reference arm needs to have an adjustable optical delay to create interference. Balanced detection systems are typically used in TD-OCT and SS-OCT systems, and a spectrometer is used at the detection port for SD-OCT systems. The invention described herein can be applied to either type of OCT system.Various aspects of the present invention may be applied to any type of OCT system or to other types of ophthalmic diagnostic systems and / or to multiple ophthalmic diagnostic systems, including but not limited to fundus imaging systems, visual field testing devices, and scanning laser polarimeters.

[0053] In Fourier Domain Optical Coherence Tomography (FD-OCT), each measurement is a real-valued spectrally controlled interferogram (Sj(k)). The real-valued spectral data typically undergoes several post-processing steps, including background removal, dispersion correction, etc. A Fourier transform of the processed interferogram gives the complex OCT signal output Aj(z)=|Aj|eiφ. The absolute value of this complex OCT signal, |Aj|, ​​reveals the scattering intensity at different path lengths and thus the scattering profile with respect to depth (z-direction) within the sample. Similarly, the phase φj can also be extracted from the complex OCT signal. The profile of the scattering with respect to depth is called an axial scan (A-scan). A collection of A-scans measured at adjacent locations within the sample produces a cross-sectional image (tomogram or B-scan) of the sample. A collection of B-scans collected at different lateral locations on the sample constitutes a data volume or cube. For a particular data volume, the fast axis refers to the scan direction along which one B-scan is collected, and the slow axis refers to the axis along which multiple B-scans are collected. The term "cluster scan" may refer to one unit or block of data generated by repeated acquisition at the same (or substantially the same) location (or region) to analyze motion contrast that may be used to identify blood flow. A cluster scan may consist of multiple A-scans or B-scans collected at approximately the same location on the sample at a relatively short time interval. Because the scans in a cluster scan are of the same region, motion contrast between scans that meet certain criteria may be identified as blood flow, while stationary structures remain relatively unchanged between scans in a cluster scan. Various methods for generating B-scans are known in the art, including, but not limited to, along the horizontal or x direction, along the vertical or y direction, along the x and y diagonals, or in a circular or spiral pattern. The B-scan may be in the xz dimension, but may also be any cross-sectional image including the z dimension.

[0054] In OCT angiography or functional OCT, analysis algorithms may be applied to OCT data collected at different times (e.g., cluster scans) at the same or nearly the same sample location on the sample to analyze motion or flow (see, e.g., U.S. Patent Application Publication Nos. 2005 / 0171438, 2012 / 0307014, 2010 / 0027857, 2012 / 0277579, and U.S. Patent No. 6,549,801, all of which are incorporated herein by reference in their entireties). The OCT system may use any one of a number of OCT angiography processing algorithms (e.g., motion contrast algorithms) to identify blood flow. For example, motion contrast algorithms may be applied to intensity information derived from the image data (intensity-based algorithms), phase information from the image data (phase-based algorithms), or complex image data (complex-based algorithms). An en face image is a 2D projection of the 3D OCT data (e.g., by averaging the intensity of each individual A-scan, whereby each A-scan defines a pixel in the 2D projection). Similarly, an en face vascular image is an image that displays a motion contrast signal in which a data dimension that corresponds to depth (e.g., the z-direction along the A-scan) is displayed as one representative value (e.g., a pixel in the 2D projection image), typically by summing or integrating all or isolated portions of the data (see, e.g., U.S. Pat. No. 7,301,644, which is incorporated herein by reference in its entirety). OCT systems that provide angiography capabilities may be referred to as OCT angiography (OCTA) systems.

[0055] An example of an en face vasculature image is shown in Figure 12. After processing the data and highlighting the motion contrast using any of the motion contrast methods known in the art, an en face (e.g., front view) image of the vasculature may be generated by summing pixel ranges corresponding to a tissue depth from the surface of the internal limiting membrane (ILM) of the retina.

[0056] Computing Devices / Systems FIG. 13 illustrates an exemplary computer system (or computing device or computer device). In some embodiments, one or more computer systems may provide functionality described or illustrated herein and / or perform one or more steps of one or more methods described or illustrated herein. A computer system may take any suitable physical form. For example, a computer system may be an embedded computer system, a system on a chip (SOC), or a single board computer system (SBC) (e.g., a computer on module (COM) or a system on module (SOM)), a desktop computer system, a laptop or notebook computer system, a mesh of computer systems, a mobile phone, a personal digital assistant (PDA), a server, a tablet computer system, an augmented / virtual reality device, or a combination of two or more of these. If appropriate, a computer system may be in a cloud, which may include one or more cloud components in one or more networks.

[0057] In some embodiments, the computer system may include a processor Cpnt1, a memory Cpnt2, a storage Cpnt3, an input / output (I / O) interface Cpnt4, a communication interface Cpnt5, and a bus Cpnt6. The computer system may also optionally include a display Cpnt7, such as a computer monitor or screen.

[0058] The processor Cpnt1 includes hardware for executing instructions, such as those that constitute a computer program. For example, the processor Cpnt1 may be a central processing unit (CPU) or a general-purpose computing-on-graphics processing unit (GPGPU). The processor Cpnt1 may read (or fetch) instructions from an internal register, an internal cache, a memory Cpnt2, or a storage Cpnt3, decode and execute the instructions, and write one or more results to the internal register, the internal cache, the memory Cpnt2, or the storage Cpnt3. In a particular embodiment, the processor Cpnt1 may include one or more internal caches for data, instructions, or addresses. The processor Cpnt1 may include one or more instruction caches, one or more data caches, for example to hold data tables. Instructions in the instruction caches may be copies of instructions in the memory Cpnt2 or the storage Cpnt3, and the instruction caches may speed up the retrieval of these instructions by the processor Cpnt1. The processor Cpnt1 may include any suitable number of internal registers and may include one or more arithmetic logic units (ALUs). The processor Cpnt1 may be a multi-core processor or may include one or more processors Cpnt1. Although this disclosure describes and illustrates a particular processor, this disclosure contemplates any suitable processor.

[0059] The memory Cpnt2 may include a main memory that stores instructions for the processor Cpnt1 to execute processing or to hold intermediate data during processing. For example, the computer system may load instructions or data (e.g., data tables) from the storage Cpnt3 or from other sources (e.g., other computer systems) into the memory Cpnt2. The processor Cpnt1 may load instructions and data from the memory Cpnt2 into one or more internal registers or internal caches. To execute an instruction, the processor Cpnt1 may read and decode an instruction from the internal register or internal cache. During or after the execution of an instruction, the processor Cpnt1 may write one or more results (which may be intermediate or final results) to the internal registers, the internal cache, the memory Cpnt2, or the storage Cpnt3. The bus Cpnt6 may include one or more memory buses (which may each include an Azures bus and a data bus) and may couple the processor Cpnt1 to the memory Cpnt2 and / or the storage Cpnt3. Optionally, one or more memory management units (MMUs) facilitate data transfer between the processor Cpnt1 and the memory Cpnt2. The memory Cpnt2 (which may be a high-speed volatile memory) may include a random access memory (RAM), such as a dynamic RAM (DRAM) or a static RAM (SRAM). The storage Cpnt3 may include a long-term or large-capacity storage for data or instructions. The storage Cpnt3 may be internal or external to the computer system and may include one or more of a disk drive (e.g., a hard disk drive HDD, or a solid-state drive SSD), a flash memory, a ROM, an EPROM, an optical disk, a magnetic optical disk, a magnetic tape, a universal serial bus (USB)-accessible drive, or other types of non-volatile memory.

[0060] The I / O interface Cpnt4 may be software, hardware, or a combination of both, and may include one or more interfaces (e.g., serial or parallel communication ports) for communicating with I / O devices, which may enable communication with a human (e.g., a user). For example, the I / O devices may include a keyboard, keypad, microphone, monitor, mouse, printer, scanner, speaker, still camera, stylus, table, touch screen, trackball, video camera, other suitable I / O devices, or a combination of two or more thereof.

[0061] The communication interface Cpnt5 may provide a network interface for communicating with other systems or networks. The communication interface Cpnt5 may include a Bluetooth interface or other types of packet-based communication. For example, the communication interface Cpnt5 may include a network interface controller (NIC) and / or a wireless NIC or wireless adapter for communication with a wireless network. The communication interface Cpnt5 may provide communication with a WI-FI network, an ad-hoc network, a personal area network (PAN), a wireless PAN (e.g., Bluetooth WPAN), a local area network (LAN), a wide area network (WAN), a metropolitan area network (MAN), a mobile phone network (e.g., a Global System for Mobile Communications (GSM) network, etc.), the Internet, or a combination of two or more of these.

[0062] The bus Cpnt6 may provide a communication link between the above-mentioned components of the computing system. For example, bus Cpnt6 may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), a HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an InfiniBand bus, a low-pin-count (LPC) bus, a memory bus, a MicroChannel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCIe) bus, a serial advanced technology attachment (SATA) bus, a Video Electronics Standards Association local (VLB) bus, or any other suitable bus, or a combination of two or more thereof.

[0063] Although this disclosure describes and illustrates a particular computer system having a particular number of particular components in a particular arrangement, this disclosure contemplates any suitable computer system having any suitable number of any suitable components in any suitable arrangement.

[0064] As used herein, a computer-readable non-transitory storage medium may include one or more semiconductor-based or other integrated circuits (ICs) (e.g., field programmable gate arrays (FPGAs) or application specific ICs (ASICs)), hard disk drives (HDDs), hybrid hard drives (HHDs), optical disks, optical disk drives (ODDs), magneto-optical disks, magneto-optical drives, floppy diskettes, floppy disk drives (FDDs), magnetic tapes, solid state drives (SSDs), RAM-drives, SECURE DIGITAL cards or drives, any other suitable computer-readable non-transitory storage medium, or any suitable combination of two or more thereof, as appropriate. A computer-readable non-transitory storage medium may be volatile, non-volatile, or a combination of volatile and non-volatile, as appropriate.

[0065] While the present invention has been described in conjunction with several specific embodiments, as will be apparent to those skilled in the art in light of the foregoing description, many other alternatives, modifications, and variations will be apparent. Accordingly, the invention described herein is intended to embrace all such alternatives, modifications, applications, and variations that may fall within the spirit and scope of the appended claims.

Claims

1. 1. A non-contact lens adapter for imaging the anterior portion of an eye, comprising: one or more reflective surfaces contained within the non-contact lens adapter, the non-contact lens adapter having a first end attachable to an ophthalmic imaging device and a second end positionable in front of the eye and not touching the eye; the non-contact lens adapter is configured to receive an imaging beam from the ophthalmic imaging device and redirect, at least in part using the one or more reflective surfaces, the imaging beam through a pupil of the eye to target one or more ocular anatomical features that are behind an iris of the eye and include or are proximate to the ciliary body of the eye; the imaging beam is redirected by the one or more reflective surfaces towards the eye at an angle of 70 degrees or greater relative to an optical center of the ophthalmic imaging device; A non-contact lens adapter, wherein at least a selected one of the one or more reflective surfaces is curved along the optical center of the ophthalmic imaging device, and the curvature of the selected one reflective surface maintains a focus at the same distance from the reflective surface on both translational axes (x-axis and y-axis) to mitigate astigmatism of the imaging light beam.

2. 2. The non-contact lens adapter of claim 1, wherein the selected one reflective surface extends around an interior of the non-contact lens adapter such that the ophthalmic imaging device can image 360 ​​degrees around the eye lens.

3. 3. A non-contact lens adapter as described in claim 1 or 2, wherein the one or more reflective surfaces include a plurality of peripheral reflective surfaces along an inner circumference of the non-contact lens adapter, each peripheral reflective surface having a different reflective angle selected to scan superiorly, inferiorly, nasally, or temporally.

4. Further comprising a central lens; the imaging beam passes through a peripheral region of the central lens to image the anterior portion of the eye; 4. A non-contact lens adapter as claimed in any one of claims 1 to 3, wherein the peripheral region is configured to focus the imaging beam onto the front of the eye or to correct aberrations in combination with one or more reflective surfaces.

5. the central lens has a central region configured to receive a second beam from the ophthalmic imaging device directed to a rear portion of the eye, the second beam being a fixation beam or a second imaging beam; 5. The non-contact lens adapter of claim 4, wherein the central region is transparent to the second beam or focuses the second beam to the back of the eye.

6. 6. The non-contact lens adapter of claim 1, wherein the ophthalmic imaging device captures multiple images of the rear of the eye through a central region of the non-contact lens adapter simultaneously with imaging the front of the eye, generates motion tracking information based on the multiple images of the rear of the eye, and applies motion correction to the images of the front of the eye based on the generated motion tracking information.

7. 7. A non-contact lens adapter as described in any one of claims 1 to 6, further comprising a second reflective surface that receives the imaging beam from the ophthalmic imaging device and redirects the imaging beam to the one or more reflective surfaces, the one or more reflective surfaces redirecting the imaging beam to an eye.

8. 8. The non-contact lens adapter of claim 7, wherein the second reflective surface is movable laterally or about a tilt axis to scan a plurality of different regions of the front of the eye.

9. a first lens configured to focus the imaging beam onto the front of the eye; and a second lens configured to focus a second imaging beam from the ophthalmic imaging region along an optical center of the ophthalmic imaging region to image a posterior segment of the eye, the first and second lenses enabling simultaneous imaging of anterior and posterior segments of the eye.

10. the one or more reflective surfaces include a first conical reflective surface; 10. A non-contact lens adapter according to any one of claims 1 to 3, claim 7 or claim 9, wherein the second reflective surface is a second conical reflective surface concentric with the first conical reflective surface.

11. 11. A non-contact lens adapter as claimed in any one of claims 1 to 3, claims 7, claims 9 or claims 10, wherein a second conical reflective surface is positioned along an optical centre of the ophthalmic imaging device and provides an unobstructed optical path for the ophthalmic imaging device to image the posterior surface of the eye through a central region of the second conical reflective surface.

12. the ocular anatomical feature comprises the zonules; 12. A non-contact lens adapter according to any one of claims 1 to 11, wherein the ophthalmic imaging device includes a data processing unit for processing imaging data and quantifying zonular indices based on the imaging data, including one or more of zonular density, zonular thickness, zonular length, zonular bifurcation points, number of zonular branches, and positions and number of contact points between the zonule and the lens or lens capsule.

13. The non-contact lens adapter of claim 12 , wherein the data processing unit is adapted to assign a health value to a zonule based on one or more zonular indices.

14. the ophthalmic imaging device includes a data processing unit for processing imaging data and quantifying a plurality of anterior ophthalmic indices based on an image of the anterior portion of the eye; 14. The non-contact lens adapter of claim 1, wherein based on the anterior ophthalmic indicia, the data processing unit assigns one or more diagnostic designations to the eye including zonular weakness, dehiscence, lens or intraocular lens (IOL) subluxation or dislocation, zonular disorder, IOL misinsertion, uveitis-glaucoma-hyphema (UGH) syndrome, ciliary body tumor, iris epithelial cyst, or posterior iris tumor.

15. 15. An ophthalmic imaging system (e.g. a fundus imaging device, an optical coherence tomography (OCT) system, or an OCT angiography system), comprising a non-contact lens adapter according to any one of claims 1 to 14.

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