OCT zonular imaging

Abstract

A system, method, or apparatus for imaging the anterior segment of an eye includes a non-contact adapter / lens that can be attached to an existing ophthalmic imaging system to redirect the light beam of the imaging system to pass through the pupil of the eye at a steep angle. In particular, the steep angle is determined to allow the ophthalmic imaging system to image the zonules of Zinn beneath the iris, which are normally blocked by the iris and unavailable for imaging.

Description

Technical Field

[0001] This invention generally relates to optical coherence tomography (OCT) imaging of the anterior portion of the eye. More specifically, this invention relates to OCT imaging directly below the iris, and particularly to imaging the suspensory ligament of the eye. Background Technology

[0002] Figure 1 The anterior portion of the eye 11 is shown, including the cornea 13, anterior chamber 15, iris 17 (the central opening of the iris defines the pupil 19), lens 21, sclera 27 (the white part of the eye), and limbus 29 (the boundary between the cornea 13 and the sclera 27). The suspensory ligament 23, a fibrous structure that holds the lens 21 in place and allows adjustment by contraction of the ciliary muscle (or ciliary body) 25, is also shown. Imaging the suspensory ligament is beneficial not only for diagnostic purposes but also for determining the current state of the suspensory ligament (e.g., number, thickness variation, integrity, strength, etc.) before medical ophthalmic surgeries (such as those that may interfere with the lens 21).

[0003] However, because the suspensory ligament 23 is located below / posterior to the iris 17, imaging of the suspensory ligament is complex, as it obstructs imaging light from directly reaching the suspensory ligament 23. Therefore, there is currently no convenient and reliable method to visualize or image the lens suspensory ligament 23. This limits the understanding of the anatomical structures and pathological processes involved in the suspensory ligament 23, which is important in conditions such as pseudoexfoliation syndrome, dispersive pigment syndrome, Marfan syndrome, Weill-Marchesani syndrome, lens ectopicness, and trauma. Furthermore, due to the lack of suspensory ligament imaging, suspensory ligament support during cataract surgery cannot be reliably assessed preoperatively. Typically, suspensory ligament weakness and suspensory ligament dialysis (a defect in the suspensory ligament support for the lens capsule, the membrane surrounding the lens 21) are only considered during cataract surgery and are an unexpected consequence for the surgeon. Because the surgeon cannot plan his operation accordingly, complications such as posterior cyst rupture and retained nuclear fragments may occur, which in turn may require additional surgery and / or affect the final surgical outcome.

[0004] Most previous efforts to visualize suspensory ligaments have focused on ultrasound biomicroscopy (UBM), which uses ultrasound to determine the depth of tissue structures by directly measuring the time delay of the returning ultrasound signal. However, UBM is time-consuming for physicians because it cannot be performed by technicians and is uncomfortable for patients. Furthermore, based on previous histopathological studies, the width of a single suspensory ligament is typically in the range of 10–30 μm, below the typical resolution limit of UBM, which is approximately 50 μm.

[0005] Optical coherence tomography (OCT) provides higher resolution imaging and is a less invasive imaging technique. While not involving imaging of the suspensory ligaments, efforts have been made to image the anterior portion of the eye at steeper angles than are typical with OCT. For example, U.S. Patents 9,517,006 and 9,936,868 to Izatt et al. describe a system for imaging the limbal region of the eye. Izatt et al. used a custom contact lens configured to direct the OCT beam toward the limbus 29 of the eye 11. However, this method requires the OCT system to contact the eye (e.g., the cornea), complicating its use and further failing to provide imaging below the iris. Izatt's method appears well-suited for imaging the iridocorneal angle within the anterior chamber. Because of the refractive index mismatch between air and the anterior segment of the eye, light is refracted, making it difficult to guide the beam to measure the iridocorneal angle. Therefore, Izatt provides a contact lens to add a medium with a similar refractive index between the optics and the cornea. The beam is not refracted at the interface. This is clear in Izatt's diagram.

[0006] The object of this invention is to provide a system and method for imaging the area in front of the eye below the iris at a steep angle.

[0007] Another object of the present invention is to provide an ophthalmic imaging system, such as a fundus imager or an OCT system, for imaging the anterior region of the eye directly below the iris, which avoids contact with the eye, for example, without contact with the cornea or sclera of the eye.

[0008] Another object of the present invention is to provide a system and method for imaging the suspensory ligaments of the eye using an ophthalmic imaging system. Summary of the Invention

[0009] The above objectives are achieved in methods / systems / apparatuses that use or include a non-contact lens adapter (e.g., an ophthalmic “cup”) that can be fitted (e.g., coupled or attached) to an existing ophthalmic imaging system (e.g., a fundus imager and / or OCT system) and allows direct imaging of the suspensory ligaments of the lens. Angular directionality can be achieved through a non-contact adapter (or cup) that can accommodate one or more transmissive and reflective optics (e.g., mirrors, retroreflectors, prisms, beam splitters, etc.) for reorienting the beam. For example, the non-contact adapter may include one or more reflective surfaces that reorient the imaging beam from the ophthalmic imaging system to the eye at a steep angle (e.g., greater than or equal to 70 degrees relative to the optical center of the imaging system) to image the area directly beneath the iris (e.g., the area including the suspensory ligaments and / or the ciliary body). Because of the refractive index mismatch between air and the anterior segment of the eye, the imaging beam is refracted at the cornea (e.g., when the imaging beam travels from air through the cornea to the anterior chamber). A steep angle at the cornea helps compensate for this refraction and allows imaging of the area directly below the iris without contact with the eye. This contrasts with the method used by Izatt above, which requires not only a shallower angle at the cornea (e.g., much smaller than a steep angle of incidence) to observe the corneal limbus of the eye above the iris (e.g., the iridocorneal angle), but also a custom-made contact lens with a special medium (in contact with the eye) having a similar refractive index between the optics and the cornea to avoid refraction at the cornea.

[0010] This suspensory ligament imaging system provides sufficiently high resolution to accurately assess the health of individual suspensory ligament fibers (e.g., including quantitative measures such as density, thickness, length, branch points, branch counts, etc.), which can provide significant diagnostic values ​​(e.g., structural health values ​​on predefined health scales).

[0011] The non-contact lens (e.g., adapter) of the present invention may include one or more planar and / or curved reflectors (or a combination of both) to aim an imaging (scanning) beam (e.g., an OCT beam) at an optimized angle below the iris (e.g., directly below) and including ophthalmic anatomical features of the ciliary body or the anterior segment of the eye near the ciliary body, such as for imaging the suspensory ligaments. This non-contact lens (adapter) further allows the patient to maintain central fixation while allowing the imaging beam to scan around the patient's lens. For example, the non-contact lens can provide an unobstructed view from the patient's eye perspective (viewpoint), enabling the patient to maintain central fixation, and even simultaneously allowing scanning around (e.g., the outer limbal region) the lens (e.g., the outer limbal region). Thus, the imaging system can be used to quantify the length, thickness, density (e.g., density distribution around the lens), branching characteristics, location and number of contact points between the suspensory ligaments and the lens and / or capsule, and other tissue characteristics to determine the structural health of the suspensory ligaments (e.g., values, grades, or class). For example, diagnostic grades can be assigned to different quantified physical characteristics based on predefined standard scales, and a weighted sum of the observed characteristic grades can be determined. An overall diagnostic grade (e.g., excellent, good, borderline, or poor) can be assigned based on the resulting weighted sum. Characteristics identified as more important for determining the suspensory ligaments' ability to withstand surgery, such as suspensory ligament count, branch count, thickness, and the number of contact points with the ciliary body and / or lens / capsule, can be weighted more heavily than other characteristics.

[0012] The above objectives are achieved in an adapter having one or more reflective surfaces to guide a first beam from an ophthalmic imaging system through the pupil of the eye at a selected optimized angle for aiming and imaging the suspensory ligaments of the eye. The ophthalmic imaging system may be one or a combination of a fundus imaging system, an optical coherence tomography (OCT) system, and both. Preferably, when imaging the suspensory ligaments, the adapter is separated from and avoids contact with the cornea or sclera of the eye. Optionally, the eye may maintain central fixation while the first 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 also be flat and closer to the optical center of the imaging system than the first reflective surface.

[0014] The reflective surface of the adapter may be eccentric, and the central region of the adapter may be configured to allow a second beam from an ophthalmic imaging system (e.g., emitted by the ophthalmic imaging system) to pass through. This second beam may be a fixation target projected into the eye and / or a second imaging beam used for imaging the eye (e.g., imaging the outer region of the eye, the cornea, or the retina).

[0015] An ophthalmic imaging system may include a computer processor that quantifies one or more tissue characteristics, including one or more of suspensory ligament length, suspensory ligament thickness, and suspensory ligament density. The computer processor may further determine a structural health grade based on the quantified one or more tissue characteristics. For example, the health grade may be based on a predefined numerical scale (e.g., a range from one to ten).

[0016] Other objects and implementations, together with a fuller understanding of the invention, will become clear and understood by referring to the following description and claims and in conjunction with the accompanying drawings.

[0017] This document may cite or reference several publications that may aid in understanding the invention. All publications cited or referenced herein are incorporated herein by reference in their entirety.

[0018] The embodiments disclosed herein are merely examples, and the scope of this disclosure is not limited thereto. Any feature of an embodiment mentioned in one claim class (e.g., system) can be claimed in another claim class (e.g., method). Dependencies or references in the appended claims are chosen only for formal reasons. However, it is also possible to claim any subject matter arising from an intentional retrospection to any prior claim, such that any combination of claims and their features can be disclosed and claimed, regardless of the dependency chosen in the appended claims. Attached Figure Description

[0019] In the accompanying drawings: the same reference symbols / characters refer to the same parts:

[0020] Figure 1 Showing the front of the eye.

[0021] Figure 2 An existing ophthalmic imaging system incorporating an adapter according to the invention is shown.

[0022] Figure 3 An exemplary OCT image is shown that can be implemented according to the present invention.

[0023] Figure 4A , Figure 4B , Figure 4C as well as Figure 4D Four exemplary embodiments of the present invention are shown.

[0024] Figure 5A , Figure 5B as well as Figure 5C Alternative embodiments of the invention are shown, wherein, Figure 2 The non-contact adapter in Figure 4 combines a second (more centrally located) reflective surface to redirect the imaging beam to the first reflective surface.

[0025] Figure 6 An alternative implementation is shown, wherein, Figure 2 The first reflective surface in Figure 5 is implemented as a first conical reflective surface / cup, and Figures 5A to 5C The secondary reflective surface is implemented as a second conical reflective surface located inside the first conical cup.

[0026] Figure 7 Provide a similar Figure 6 However, it has a tapered structure with an open area along the optical center of the ophthalmic imaging system.

[0027] Figure 8A and Figure 8B Showing similar to Figure 5A and Figure 5B In this implementation, a secondary focusing lens 65 is added within the contactless adapter to assist in focusing one or more second beams.

[0028] Figure 9A , Figure 9B as well as Figure 9C An alternative view of an exemplary embodiment of the invention is shown, illustrating the exit aperture coupled to an ophthalmic imaging system.

[0029] Figure 10 An example of a slit-scan ophthalmic system for imaging the fundus is shown.

[0030] Figure 11 A general-purpose frequency-domain optical coherence tomography system for collecting 3-D image data of the eye is shown, suitable for use with the present invention.

[0031] Figure 12 An example of a frontal vascular system image is shown.

[0032] Figure 13 An example computer system (or computing device or computer) is shown.

[0033] Preferred Implementation

[0034] This system provides an unprecedented level of detail in viewing the ophthalmic structures behind the iris. In particular, it reliably identifies the anatomy and any pathology of the patient's suspensory ligament fibers and peripheral lens (the peripheral region of the lens). The system has been shown to be rapid and effective while avoiding any direct contact with the patient's eye (e.g., no contact with the cornea or sclera). The specific implementation has been optimized for easy adaptation to existing ophthalmic imaging systems and for easy use by those trained to use these existing systems. Therefore, the invention can be integrated into current cataract and anterior segment ophthalmology practice with minimal effort.

[0035] For illustrative purposes, Figure 2 A representation of a conventional ophthalmic imaging system 12 (such as a fundus imager or optical coherence tomography (OCT) system) incorporating an adapter 41 according to the invention is shown. Fundus imagers typically capture two-dimensional (2D) planar images of the fundus of the eye (e.g., the retina). OCT systems can generate 2D or three-dimensional (3D) images of subcutaneous tissues (such as various tissue layers of the retina). OCT systems can generate images of the anterior segment of the eye (such as the cornea) or the posterior segment of the eye (such as the retina). OCT angiography can provide images of the retinal vascular system (blood flow), and anterior segment OCT (AS-OCT) can be specifically used for imaging the anterior region of the eye using an additional adapter. References below... Figures 10 to 13 A more detailed discussion is provided of various exemplary ophthalmic imaging systems suitable for use with the present invention.

[0036] In any case, a typical ophthalmic imaging system typically has an aperture 14 through which the imaging beam (or imaging light) 16 of the ophthalmic imaging system is emitted to image the eye. The imaging beam will typically have a limited angular range, which limits the field of view of the ophthalmic imaging system. In addition, various anatomical features of the eye, such as the imaging beam 16 (as shown by the bouncing arrow 16a), cannot penetrate the iris, and thus limit which parts of the eye can be imaged. For example, the 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 can increase the incident angle of the imaging (light) beam 43 (e.g., the angle of the optical center (or optical axis) 47 of the ophthalmic imaging system 12) to enter the pupil 19 of the eye at a steep angle and reach the anterior segment of the eye directly below the iris, which was previously inaccessible. For example, by using a non-contact adapter 41, the functionality of the ophthalmic imaging system 12 can be extended to image the suspensory ligaments, which was previously impractical. Although not shown for ease of illustration, it should be understood that the imaging beam 43 is refracted at the cornea due to the refractive index mismatch between the air interface and the anterior segment of the eye. Therefore, the imaging beam 43 can be applied at the cornea at a steeper angle (e.g., greater than 70°) than at the pupil to resolve the refraction at the interface, while still having a sufficiently steep angle at the pupil to image directly below the iris.

[0037] This increase in the angle of incidence can be achieved by modifying the internal optics of the ophthalmic imaging system, but such modification is currently preferred to avoid. Instead, some embodiments of the 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 of the ophthalmic imaging system from its normal exit aperture 14 to an axially offset and angled aperture 41' to generate a steep imaging beam 43. Alternatively, if the ophthalmic imaging system is already configured to accept existing aperture adapters, such as AS-OCT, the non-contact adapter 41 can be configured to have a coupling mechanism similar to that of existing aperture adapters to allow interchangeability with existing aperture adapters for the ophthalmic imaging system. Alternatively, the non-contact adapter of the present invention can be made with a dedicated coupling mechanism configured to couple to a specific ophthalmic imaging system.

[0038] Figure 3 An exemplary OCT image 31, achievable using the present invention, is shown. The health and stability of the suspensory ligament fibers are key factors affecting the outcome of cataract surgery. Because this structure is located behind the iris, it is difficult to visualize preoperatively, blocking light and preventing scattering. For illustrative purposes, a dashed square 39 generally delineates a portion of a schematic eye 11, which may correspond to a portion of a real eye as shown in image 31. An exemplary imaging beam (or imaging beam) 43, such as from an OCT system, is shown entering the cornea 13 at a steep angle (e.g., approximately 70°) and refracting at the cornea 13 due to the refractive index mismatch between air and the anterior segment, continues through the pupil 19 to image the lower region of the suspensory ligament 23 (and / or ciliary body 25) beneath the iris 17. This embodiment enables reliable imaging of the anatomical location of the peripheral lens (e.g., the peripheral region of the lens 21, including the capsular bag or lens capsule 21' enclosing the lens 21), the anterior vitreous body 33, and the posterior suspensory ligament 23'. This method allows individual suspensory ligament fibers 35 to be resolved in image 31. It can be understood that the upper portion 23” of the suspensory ligament 23 can be imaged by applying an imaging optical beam 43 at an even steeper angle (e.g., forming a shallow (small) angle 9 below the iris 17 relative to a horizontal reference line orthogonal to the optical axis (e.g., at the iris).

[0039] Clinical studies are being conducted to evaluate the feasibility of using swept-source optical coherence tomography (SS-OCT) to image the suspensory ligaments. PLEX 9000 ( Dublin, CA)SS-OCT utilizes external additional lenses (e.g., Figure 2The adapter 41 (+20 diopters) was modified to image the anterior segment of the eye. Healthy subjects were recruited and expanded for this study. The suspensory ligament structures were imaged using a 4.5 × 1.5 mm scanning mode that captures 300 A scans in a single B scan frame. Each B scan was repeated, registered, and averaged 10 times to reduce speckle noise. A total of 51 B scans were performed in the cube. Eye motion tracking was disabled for this study, but the scanning mode was designed to acquire all data in less than two seconds to minimize motion artifacts. Five subjects (aged 18 to 65 years) were successfully imaged. The steep incision angle allowed incident light to pass through the lens 21 and reach a portion of the suspensory ligament cluster 23, avoiding obstruction from the iris 17. This preliminary imaging technique allowed imaging of approximately half the length of the suspensory ligament cluster. Additionally, a strong signal was identified behind the lens capsule 21', which may represent the anterior vitreous surface of the vitreous body. This invention demonstrates for the first time the imaging of suspensory ligament structures and the anterior vitreous body using SS-OCT. The advantage of this system is that it provides an unprecedentedly detailed view of the structures behind the iris and has the potential to help identify the anatomical structures of the patient's suspensory ligament fibers, peripheral lens, and anterior vitreous body, thereby aiding in surgical planning.

[0040] Therefore, this invention provides a view of the anatomical structures behind the iris and enables reliable identification of the patient's suspensory ligament fibers and the anatomy of the peripheral lens, as well as any pathology. Furthermore, this invention is rapid and avoids any direct contact with the patient's eye (e.g., cornea and / or sclera), which facilitates its use. As explained more fully below, this invention can be integrated into existing ophthalmic imaging systems. Therefore, this system can be easily used by technicians already trained to use existing ophthalmic imaging systems without additional training. Consequently, this invention can be integrated into existing cataract and anterior segment ophthalmology practices, thereby providing new and important diagnostic information with minimal interference to existing surgical procedures.

[0041] For example, front-end optical coherence tomography (AS-OCT) can already utilize a removable, specialized lens system. This invention can be incorporated into an adapter (or “OCT eyecup”) that provides another specialized lens system interchangeable with existing AS-OCT systems.

[0042] An exemplary field where this invention can be readily applied is in the fields of cataract surgery and intraocular lens implantation. The success of such surgery is linked to the physical condition of the patient's suspensory ligaments, but until now, the condition of these ligaments has not been easily observed / identified before or after surgery. Because this invention allows for direct 3D imaging of the suspensory ligaments using AS-OCT with a specialized lens adapter, it becomes possible to diagnose and assist in the management of suspensory ligament weakness and / or (suspensory ligament) tearing in the context of cataract surgery. This invention can also be used to assist in determining the precise power of the intraocular lens (IOL) implanted during cataract surgery to achieve ideal refractive results. This invention can also be used to diagnose and assist in the management of postoperative suspensory ligament weakness and / or tearing after cataract surgery. This system also allows for the diagnosis of lens or IOL subluxation or dislocation, as well as suspensory ligament disorders associated with: trauma; previous surgery; advanced age; pseudo-peeling syndrome; pigment dispersion syndrome; Marfan syndrome; Ehler-Danlos syndrome; Weill-Marchesani syndrome; homocystinuria; aniridia; lens ectopic; lens and pupil ectopic; ciliary body defects; and / or hypermature cataracts. This invention can also be used to diagnose misaligned IOLs (outside the capsular bag), uveitis-glaucoma-hypopnea (UGH) syndrome, ciliary body tumors, iris epithelial cysts, and posterior iris tumors. Diagnosis can be made by visual examination of the captured images by trained professionals, or by using quantification metrics and standard scales for various medical conditions, and / or by computerized systems that utilize decision trees, linear regression, support vector machines (SVMs), or neural networks trained to recognize the diagnostic images listed above using this imaging technique.

[0043] Figures 4A to 4D Four exemplary embodiments of the present invention are shown. (See references) Figure 4AThe present invention may include a non-contact adapter (non-contact, or non-contact lens) 41 (optionally, a radial (e.g., circular) adapter and / or a radially symmetrical adapter), such as an “OCT / imaging eye cup,” for use with an ophthalmic imaging system 40 (such as an OCT, OCTA, fundus imager, or a combination thereof) to illuminate and image ophthalmic anatomical features that are typically obscured by the iris (such as the suspensory ligaments of the eye), and these ophthalmic anatomical features may be located in an anterior (e.g., circumferential) region of the eye (e.g., directly below the iris). For illustrative purposes, the ophthalmic imaging system 40 is indicated by a dashed arrow, and the eyepiece (or ophthalmic) lens OL of the ophthalmic imaging system 40 is also shown. Typically, the eyepiece OL is the lens of the ophthalmic imaging system 40 closest to the patient's eye E, and the imaging beam (e.g., scanning beam) 43 of the system passes through this lens to exit the ophthalmic imaging system 40 and enter the eye E. The eyepiece OL focuses the imaging beam 43 onto the object to be imaged, and typically guides the imaging beam 43 along the optical center 47 of the ophthalmic imaging system 40 to image the posterior portion of the eye E (e.g., the fundus / retina F). However, in this case, the imaging beam 43 scans the peripheral region of the eyepiece OL, and the adapter (non-contact lens) 41 redirects the peripheral imaging beam 43 at a steep angle through the pupil onto the anterior portion of the eye E. The adapter 41 may have a curved and / or angled reflective surface 45 that guides the imaging beam 43 at a high angle relative to the optical center 47 of the imaging system (e.g., guiding the imaging optical path of the ophthalmic imaging system). For example, in the case of imaging the suspensory ligament, the adapter 41 can guide the imaging beam 43 from the optical center 47 into the eye E and to the suspensory ligament of the eye at an angle of approximately 70 degrees or greater without being intercepted / blocked by the iris of the eye. The reflective surface 45 can be a continuous curved surface along the inner periphery of the adapter 41, or it can be one or more discrete (flat or curved) reflective surfaces (e.g., mirror surfaces) located at predetermined positions and angles within the inner periphery of the adapter 41 to guide the imaging optical path of the ophthalmic imaging system at predetermined positions along the anterior segment of the eye. The reflective surface 45 can be a peripherally curved reflective surface with a conical segment shape having curvature along the z-axis 47 (e.g., the optical center of the imaging system). The curvature of the reflective surface 45 can be used to generate a focal point at equal distances from the reflective surface 45 on both translation axes (e.g., the x-axis and y-axis), thereby preventing (or mitigating) astigmatism in illumination and imaging. In one embodiment, the eyepiece OL can guide the imaging beam 43 using a single curved mirror 45 combined with a customized scanning pattern, allowing the ophthalmic imaging system 40 to image around the lens of the eye E in 360 degrees, and thus capturing all suspensory ligaments in a single shot. Alternatively, several mirror surfaces 45 can be used to scan upward, downward, nasal, and / or temporal regions respectively using multiple acquisitions (e.g., multiple scan operations).The reflective surface 45 may be a single reflector at each location, or multiple reflectors in each quadrant, each reflector being characterized by a slightly different reflection angle in order to accommodate (e.g., small) anatomical variations between subjects (e.g., patients).

[0044] For use Figure 4A The imaging system correctly images the posterior segment of the eye through the central region of the eyepiece OL and correctly images the anterior segment of the eye through the peripheral region of the eyepiece OL and the reflective surface 45, which allows the focal length of the ophthalmic imaging system 40 to be long enough to focus on objects in the anterior region of the eye (e.g., the suspensory ligament) and objects in the posterior region of the eye (e.g., the fundus / retinal region F).

[0045] like Figure 4B As shown, if the optimized ophthalmic imaging system 40 is used to focus on the posterior segment of the eye and has difficulty focusing on the anterior region of the eye, then the adapter 41 can be combined with the central lens 49 to assist in focusing the system's imaging beam 43 onto the desired anterior segment of the eye, for example, onto the suspensory ligament. (See above reference...) Figure 4A The subject of discussion Figure 4B The reflecting surface 45 can be a peripherally curved reflecting surface with a conical segment shape having curvature along the z-axis, and the curvature of the reflecting surface 45 can be used to generate a focal point at the same distance from the reflecting surface 45 on both translation axes to prevent astigmatism in illumination and imaging. Optionally, the outer region (e.g., the peripheral region) of the central lens 49 (e.g., the portion through which the system's imaging beam 43 passes to image the suspensory ligament) can be used with the reflecting surface 45 (e.g., which can be a conical mirror) to correct aberrations when needed. In this configuration, the imaging system can be used to image either the anterior or posterior segment 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 image the retina F of the eye E directly. When imaging the suspensory ligaments of the eye, or other anterior features of the eye that are typically obscured / blocked by the iris, the adapter 41 is then placed (e.g., attached) to the ophthalmic imaging system 40 to increase the angle of incidence of the imaging beam 43 at the pupil. Alternatively, selectively removing the adapter 41 when imaging the posterior segment of the eye is desired would involve removing (or making substantially transparent) the central region of the central lens 49 so as not to interfere with the imaging beam 43 of the system when imaging the posterior segment 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 requiring selective removal or replacement depending on whether the anterior or posterior segment of the eye is being imaged.

[0046] Figure 4CAn alternative configuration is provided that allows simultaneous focusing on both the anterior and posterior segments of the eye. In this case, the peripheral region 49p of the central lens 49 will focus in a manner similar to... Figure 4B The imaging beam 43 of the system functions in a manner that assists in focusing the system's imaging beam 43 onto the anterior segment of the eye. However, it is desirable to simultaneously have a second beam 44, which can be focused (and optionally scanned across the posterior segment of the eye) onto the posterior segment of the eye, such as through an internal region 49i of a central lens 49 configured to focus the second beam 44 onto the posterior segment of the eye. If it is desirable to image the fundus F (e.g., by means of a scanning laser ophthalmoscopy (SLO) or other fundus imaging system) while simultaneously imaging the suspensory ligaments of the eye (e.g., by using an OCT system), the image from the SLO can be used to generate motion tracking information by comparing the currently captured image with a previously referenced image. The motion tracking information can be used for motion correction of the system's imaging beam 43 and / or for motion aberration correction of the image obtained by the system's imaging beam 43 in post-processing. Alternatively or additionally, it is desirable to project a fixation target through the internal region 49i of the central lens 49 to guide the patient's gaze direction while imaging the anterior segment of the eye (e.g., the suspensory ligaments). For example, it has been found that when imaging from the nasal direction, a person's nose can obstruct the imaging beam 43, and this obstruction can be reduced by moving the patient's fixation point away from the nose (e.g., moving the patient's pupil away from the nose). For example, when imaging the suspensory ligament on the side furthest from the nose, the fixation target can be used to guide the patient to look away from the nose. Thus, the inner region 49i can be configured to provide fixation imaging via a beam splitter (preferably a dichroic beam splitter), provide retinal imaging (which can provide motion tracking), or provide both fixation and retinal imaging simultaneously.

[0047] Figure 4D In another embodiment, as discussed above, the interior region of the central lens 49 may be removed or made transparent so as not to interfere with the optical path along the optical center of the imaging system. In this case, the peripheral region 49p assists in focusing the imaging beam 43 onto the anterior segment of the eye, and the open interior region of the central lens 49 allows the secondary beam 44 to pass unobstructed through the posterior segment of the eye E. As discussed 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 secondary fundus imaging functions (such as for motion tracking), or both.

[0048] Figure 5A , Figure 5B as well as Figure 5C Alternative embodiments of the invention are shown, wherein, Figure 2The non-contact adapter 41 in Figure 4, combined with a second reflective surface 61, redirects the imaging beam 43 to the angled reflective surface 45 described above. The use of the secondary reflective surface 61 helps guide the imaging beam 43 into the eye at the desired steep angle. Figure 5A In this embodiment, 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 can be scanned across reflective surfaces 61 and 45 to scan across the target region of the eye E. In this case, the region of the eye E being scanned is the region furthest from the reflective surface 45. Figure 5B The repositioning of reflective surfaces 61 and 45 is shown to scan (e.g., image) another anterior region of the eye E. In this case, reflective surface 61 can be rotated about the z-axis to face different directions, and reflective surface 45 can be repositioned (e.g., moved to different positions or have multiple reflective surfaces 45 at key scanning positions) to scan the eye E from different directions. In this case, the imaging beam 43 is scanned at different peripheral regions of the central lens 49 and the eyepiece OL. Alternatively, as Figure 5C As shown, the position of the secondary reflective surface 61 can be shifted laterally and / or its angle can be changed to achieve the desired effect on the opposite surface (e.g., ...). Figure 5A The imaging beam 43 is received on (as shown), and thus in a different image than... Figure 5A The direction of the imaging beam 43 is changed in the z-axis to avoid rotating the secondary reflective surface 61 around the z-axis. In this way, the scanning of the imaging beam 43 can remain focused on a single area of ​​the central lens 49 and the eyepiece OL, while still scanning multiple opposite sides of the anterior region of the eye E.

[0049] Figure 6 An alternative implementation is shown, wherein, Figure 2 The angled reflective surface 45 in Figure 5 is implemented as a conical cup 45', and Figures 5A to 5C The secondary reflective surface 61 is replaced by a secondary conical reflective surface 61' located (e.g., concentric with it) at the conical cup 45'. The conical cup 45' may be open at both sides, or the central lens 49 may be fixed to the opening of the conical cup 45'. In this configuration, a 360-degree image of the anterior segment of the eye E can be generated by a peripheral scanning imaging beam 43 surrounding the eyepiece OL and the central lens 49. However, this configuration can complicate the imaging of the eye E along the optical center 47 of the ophthalmic imaging system due to the interference of the secondary conical reflective surface 61'. Therefore, the non-contact adapter 41 can be removed from the ophthalmic imaging system when imaging the anterior segment of the eye E at a steep imaging angle.

[0050] Figure 7 Provide a kind of Figure 6 Similar cone-shaped structure, but with a shape like in Figure 4D The open area 63 along the optical center 47 of the ophthalmic imaging system (or with a transparent lens or additional central lens to assist focusing, such as...) Figure 4C (As shown), this configuration allows imaging of both the front and rear regions of the eye E without requiring the removal of the contactless adapter 41. In this case, 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 allows simultaneous imaging of the front and rear regions of the eye E using a secondary imaging beam, such as... Figure 4C and Figure 4D As shown.

[0051] Figure 8A and Figure 8B Showing similar to Figure 5A and 5B In this implementation, a secondary focusing lens 65 is added within the contactless adapter 41 to assist in focusing in a manner similar to... Figure 4C One or more second beams 44 are focused in a manner that allows the internal region 49i to focus the light. As discussed above, the second beams 44 can provide fixation and / or secondary imaging capabilities (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 may include a plane mirror for redirecting the beam of the tilted scan at a 70° angle into the eye. It may also include lenses for adjusting convergence and divergence and numerical aperture (i.e., spot size) on the anterior segment of the eye. For 360° coverage, parabolic or aspherical mirrors (or other reflective surfaces) may be used, such as... Figure 4A , Figure 4B , Figure 4C , Figure 4D , Figure 6 as well as Figure 7 As shown. Alternatively, the optics can be optimized to remove the astigmatism added from the parabolic mirror.

[0052] Figure 9A , Figure 9B as well as Figure 9C An alternative view of an exemplary embodiment of the invention is shown, illustrating an exit aperture 14 coupled to an ophthalmic imaging system. Figure 9A A partial cross-sectional view of a non-contact adapter / lens 41 attached to an exit aperture 14 of an ophthalmic imaging system according to the present invention is shown. In this example, the non-contact adapter 41 extends from the opening 14 at a steep angle to provide an imaging beam 43 and an image eye E. Figure 9B Show Figure 9A A closed view of the hole 14 coupled to the contactless adapter 41. Figure 9CA top view of a non-contact adapter 41 according to the invention for imaging the anterior segment of the right eye (not shown) of a patient 67 is provided. The non-contact adapter 41 is shown coupled to an aperture 14 located anterior to the patient's right eye, between the patient's nose 68 and eyebrow 69.

[0053] The following provides a description of various hardware and architectures suitable for this invention.

[0054] Fundus imaging system

[0055] Two types of imaging systems used for imaging the fundus are flood illumination imaging systems (or flood illumination imagers) and scanning illumination imaging systems (or scanning imagers). Flood illumination imagers, for example, utilize light to simultaneously flood the entire field of view (FOV) of interest of a sample using a flash lamp, and capture a full-frame image of the sample (e.g., the fundus) using a full-frame camera (e.g., a camera with a two-dimensional (2D) light sensor array of sufficient size to capture the desired FOV as a whole). For example, a flood illumination fundus imager would flood the fundus of the eye with light and capture a full-frame image of the fundus in a single image capture sequence from the camera. Scanning imagers provide a scanning beam that scans across the subject (e.g., the eye), and as the scan is performed across the subject, the scanning beam images at different scanning locations, producing a series of image fragments (e.g., clipped images) that can be reconstructed to produce a synthetic 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.

[0056] Figure 10An example of a slit-scanning ophthalmic system SLO-1 for imaging the fundus F is shown. The fundus F is the internal surface of the eye E opposite to the lens (or crystalline lens) CL of the eye and may include the retina, optic disc, macula, fovea, and posterior pole. In this example, the imaging system is in a so-called “scan-to-de-scan” configuration, wherein a scanning beam SB passes through the optical components of the eye E (including the cornea Crn, iris IRs, pupil Pp1, and lens CL) to scan across the fundus F. In the case of a floodlight fundus imager, a scanner is not required, and light is applied at once across the entire desired field of view (FOV). Other scanning configurations are known in the art, and a specific scanning configuration is not critical to the invention. As depicted, the imaging system includes one or more light sources LtSrc, preferably a multicolor LED system or a laser system, wherein the light spread has been appropriately adjusted. An optional slit Slt (adjustable or static) is positioned in front of the light source LtSrc and can be used to adjust the width of the scanning beam SB. Additionally, the slit Slt can remain static during imaging or can be adjusted to different widths to allow for different confocal levels and applications during scanning for specific purposes or to suppress reflections. An optional objective lens ObjL can be placed in front of the slit Slt. The objective lens ObjL can be any lens in the prior art, including but not limited to refractive, diffractive, reflective, or hybrid lenses / systems. Light from the slit Slt passes through the pupil-splitting reflector SM and is directed to the scanner LnScn. It is desirable to bring the scanning plane and the pupil plane as close together as possible to reduce vignetting in the system. Optional optics DL can be included to manipulate the optical distance between the images of the two components. The pupil-splitting reflector SM can transmit the illumination beam from the light source LtSrc to the scanner LnSCn and reflect the detection beam from the scanner LnSCn (e.g., reflected light returning from the eye E) toward the camera Cmr. The task of the pupil-splitting reflector SM is to split the illumination beam and the detection beam and to assist in suppressing system reflections. The scanner LnScn can be a rotating galvanometer scanner or other types of scanners (e.g., piezoelectric or voice coil, microelectromechanical systems (MEMS) scanners, electro-optic deflectors, and / or rotating polygon scanners). Depending on whether pupil segmentation is performed before or after the scanner LnSCn, the scan can be divided into two steps, where one scanner is in the illumination path and a separate scanner is in the detection path. A specific pupil segmentation arrangement is described in detail in U.S. Patent No. 9,456,746, the entire contents of which are incorporated herein by reference.

[0057] An illumination beam passes from a scanner LnSCn through one or more optics, in this case, a scanning lens SL and an ophthalmic lens or eyepiece OL, which allow the pupil of the eye E to image onto the system's image pupil. Typically, the scanning lens SL receives the scanning illumination beam from the scanner LnScn at any of a plurality of scanning angles (incident angles) and produces a scanning beam SB with a substantially flat surface focal plane (e.g., a collimated optical path). The ophthalmic lens OL can then focus the scanning beam SB onto the object to be imaged. In this example, the ophthalmic lens OL focuses the scanning beam SB onto the fundus F (or retina) of the eye E to image the fundus. In this way, the scanning beam SB produces a transverse scanning line traveling through the fundus F. One possible configuration for these optics is a Keplerian telescope, in which the distance between the two lenses is chosen to produce an approximately telecentric intermediate fundus image (4-f configuration). The ophthalmic lens OL can be a single lens, an achromatic lens, or an arrangement of different lenses. As known to those skilled in the art, all lenses can be refractive, diffractive, reflective, or a combination of these. The focal lengths of the ophthalmic lens OL, the scanning lens SL, and the size and / or form of the pupillary segmentation mirror SM and the scanner LnScn can vary depending on the desired field of view (FOV). Therefore, an arrangement can be envisioned in which multiple components can be switched in and out of the beam path, depending on the field of view, for example, by using flippers, motorized wheels, or detachable optical elements. Since changes in the field of view result in different beam sizes at the pupil, pupillary segmentation can also vary in conjunction with changes in FOV. For example, a 45° to 60° field of view is typical or standard for fundus cameras. Higher fields of view, such as 60° to 120° or greater, such as wide-field FOVs, are also feasible. Wide-field FOVs can be expected for combinations of wide-line fundus imaging (BLFI) with other imaging modalities such as optical coherence tomography (OCT). The upper limit of the field of view can be determined by the achievable working distance combined with the physiological conditions surrounding the human eye. Because the typical human retina has a field of view (FOV) of 140° horizontally and 80° to 100° vertically, an asymmetrical field of view can be expected for the highest possible FOV on the system.

[0058] The scanning beam SB passes through the pupil Pp1 of the eye E and is directed to the retina or fundus surface F. The scanner LnScnl adjusts the position of the light on the retina or fundus F so that a range of lateral positions on the eye E is illuminated. The reflected or scattered light (or emitted light in the case of fluorescence imaging) is guided back along a similar path to the illumination to define the collection beam CB on the detection path to the camera Cmr.

[0059] In the "scan-de-scan" configuration of this exemplary slit-scan ophthalmic system SLO-1, the light returning from the eye E is "de-scanned" by the scanner LnSCn on its path to the pupillary segmentation mirror SM. That is, the scanner LnSCn scans the illumination beam from the pupillary segmentation mirror SM to define a scan illumination beam SB across the eye E, but because the scanner LnSCn also receives the returning light from the eye E at the same scanning position, the scanner LnSCn has a de-scan (e.g., cancel scan action) returning light to define a non-scan (e.g., stable or stationary) collected beam from the scanner LnSCn to the pupillary segmentation mirror SM, which folds the collected beam toward the camera Cmr. At the pupillary segmentation mirror SM, the reflected light (or emitted light in the case of fluorescence imaging) is separated from the illumination light onto the detection path of the camera Cmr, which can be a digital camera with a light sensor to capture an image. An imaging (e.g., objective) lens ImgL can be positioned in the detection path to image the fundus onto the camera Cmr. For example, in the case of the objective lens ObjL, the imaging lens ImgL can be any type of lens known in the art (e.g., a refractive lens, a diffractive lens, a reflective lens, or a hybrid lens). Further operational details, particularly methods for reducing artifacts in images, are described in PCT Publication WO2016 / 124644, the contents of which are incorporated herein by reference in their entirety. The camera Cmr captures received images, for example, which generates image files that can be processed by one or more (electronic) processors or computing devices (e.g., ...). Figure 13 The computer system further processes the data. Thus, the collected beam (returning from all scan positions of the scan line beam SB) is collected by the camera Cmr, and the full-frame image IMG can be constructed from the composition of a single captured collected beam, such as by clipping the image. However, other scanning configurations are also envisioned, including configurations in which the illumination beam is scanned across the eye E and the collected beam is scanned across the camera's light sensor array. PCT Publication WO 2012 / 059236 and US Patent Publication 2015 / 0131050 describe several embodiments of a slit scanning ophthalmoscope, including different designs in which the returned light sweeps across the camera's light sensor array and in which the returned light does not sweep across the camera's light sensor array.

[0060] In this example, the camera Cmr is connected to a processor (e.g., a processing module) Proc and a display (e.g., a display module, computer screen, electronic screen, etc.) Dspl. Both can be part of the imaging system itself, or they can be part of a separate, dedicated processing and / or display unit, such as a computer system, where data is transmitted from the camera Cmr to the computer system via cable or a computer network including wireless networks. The display and processor can both be in a single unit. The display can be a conventional electronic display / screen or a touchscreen type, and can include a user interface for displaying and receiving information from the instrument operator or user. The user can interact with the display using any type of user input device known in the art, including but not limited to a mouse, knob, button, pointer, and touchscreen.

[0061] It is desirable for the patient's gaze to remain fixed during imaging. One way to achieve this is to provide a fixation target that can guide the patient's gaze. The fixation target can be internal or external to the instrument, depending on which area of ​​the eye is to be imaged. One implementation of an internal fixation target is... Figure 10 As shown in the diagram. In addition to the primary light source LtSrc used for imaging, a second optional 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 guides 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 at the pupillary plane of the system, allowing the light pattern on the retina / fundus to be moved according to the desired fixation position.

[0062] Slit-lamp ophthalmoscope systems can operate in different imaging modes depending on the light source and wavelength-selective filtering elements used. When imaging the eye using a series of colored LEDs (red, blue, and green), true color reflectance imaging (similar to the imaging observed by clinicians when examining the eye with a handheld or slit-lamp ophthalmoscope) can be achieved. Each LED can be activated at each scanning position to progressively build an image for each color, or each color image can be captured individually. These three color images can be combined to display a true color image, or they can be 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 anterior retina. Furthermore, light of a specific frequency (e.g., a single colored LED or laser) can be used to excite different fluorophores in the eye (e.g., autofluorescence), and the generated fluorescence can be detected by filtering out the excitation wavelength.

[0063] Fundus imaging systems can also provide infrared reflection images, for example, by using an infrared laser (or other infrared light source). The advantage of infrared (IR) mode is that the eye is insensitive to IR wavelengths. This allows for continuous image capture without interfering with the eye (e.g., in preview / alignment mode) to assist the user during instrument alignment. Furthermore, IR wavelengths have increased tissue penetration and can improve visualization of choroidal structures. Additionally, fluorescein angiography (FA) and indocyanine green (ICG) angiography imaging can be performed by collecting images after the fluorescent dye has been injected into the subject's bloodstream. For example, in FA (and / or ICG), a series of time-lapse images can be captured after a photoreactive dye (e.g., a fluorescent dye) has been injected into the subject's bloodstream. Note that caution must be exercised because fluorescent dyes can cause life-threatening allergic reactions in some populations. High-contrast, grayscale images are captured by using selected specific light frequencies to excite the dye. As the dye flows through the eye, different parts of the eye emit bright light (e.g., fluorescence), making the progress of the dye discernible, and thus the flow of blood through the eye.

[0064] Optical coherence tomography imaging system

[0065] In addition to fundus photography, fundus autofluorescence (FAF), and fluorescein angiography (FA), ophthalmic images can also be created using other imaging modalities, such as optical coherence tomography (OCT), OCT angiography (OCTA), and / or ocular ultrasound angiography. The present invention, or at least a portion thereof, with minor modifications as understood in the art, can be applied to these other ophthalmic imaging modalities. More specifically, the present invention can also be applied to ophthalmic images generated by OCT / OCTA systems that produce OCT and / or OCTA images. For example, the present invention can be applied to frontal OCT / OCTA images. Examples of fundus imagers are provided in U.S. Patents 8,967,806 and 8,998,411. Examples of OCT systems are provided in U.S. Patents 6,741,359 and 9,706,915. And examples of OCTA imaging systems are provided in U.S. Patents 9,700,206 and 9,759,544, all of which are incorporated herein by reference in their entirety. For completeness, an exemplary OCT / OCTA system is provided in this document.

[0066] Figure 11A general-purpose frequency-domain optical coherence tomography (FD-OCT) system suitable for use with this invention for collecting 3-D image data of the eye is shown. 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 time coherence lengths or swept-frequency laser sources. The beam from the light source LtSrc1 is typically routed through an optical fiber Fbr1 to illuminate a sample (e.g., the eye E); a typical sample is tissue in the human eye. For example, the light source LrSrc1 can be a broadband light source with a short time coherence length in the case of spectral domain OCT (SD-OCT), or a laser source with wavelength tunable in the case of swept-frequency source OCT (SS-OCT). Typically, a scanner Scnr1 can be used to scan the light between the output of the optical fiber Fbr1 and the sample E, such that the beam (dashed line Bm) scans laterally over the region of the sample to be imaged. The beam from the scanner Scnr1 can pass through a scanning lens SL and an ophthalmic lens OL and be focused onto the imaged sample E. This example illustrates a scan beam that needs to be scanned in two lateral directions (e.g., the x and y directions in the Cartesian plane) to scan a desired field of view (FOV). An example of this would be a point-field OCT using a point-field beam to scan across the sample. Thus, the scanner Scanr1 is illustrated 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., the horizontal x direction); and a second sub-scanner Yscn for scanning the point-field beam across the sample in a second direction (e.g., the vertical y direction). If the scan beam is a line-field beam (e.g., a line-field OCT), which can sample the entire line portion of the sample at once, only one scanner is needed to scan the line-field beam across the sample to span the desired FOV. If the scan beam is a full-field beam (e.g., a full-field OCT), no scanner is needed, and the full-field beam can be applied across the entire desired FOV at once.

[0067] 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 fiber Fbr1 used to route the light for illumination. The reference light originating from the same light source LtSrc1 travels in a separate path, in this case involving fiber Fbr2 and a back reflector RR1 with adjustable optical delay. Those skilled in the art will recognize that a transmission reference path can also be used, and the adjustable delay can be placed in either the sample arm or the reference arm of the interferometer. The collected sample light is combined with the reference light, for example, in a fiber coupler Cplr1, to form an optical interference in an OCT photodetector Dtctr1 (e.g., a photodetector array, a digital camera, etc.). Although a single fiber port is shown leading to detector Dtctr1, those skilled in the art will recognize that various designs of the interferometer are capable of being used for balanced or unbalanced detection of interference signals. The output from detector Dtctr1 is provided to a processor (e.g., an internal or external computing device) Cmp1, which converts the observed interference into depth information of the sample. Depth information can be stored in memory associated with processor Cmp1 and / or displayed on a display (e.g., computer / electronic display / screen) Scn1. Processing and storage functions can be localized within the OCT instrument, or functions can be offloaded to an external processor (e.g., an external computing device) (e.g., executed on an external processor), and collected data can be transferred to the external processor. An instance of a computing device (or computer system) is... Figure 13 As shown in the diagram. This unit can be dedicated to data processing or to performing other tasks that are very common and not specific to OCT devices. 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 a combination thereof, which can perform some or all of the processing steps in a serial and / or parallel manner with one or more host processors and / or one or more external computing devices.

[0068] The sample and reference arms in the interferometer can be composed of bulk optics, fiber optics, or hybrid bulk optics systems, and can have different architectures, such as Michelson, Mach-Zehnder, or common-path-based designs known to those skilled in the art. The beams used herein should be interpreted as any carefully oriented optical path. Instead of mechanically scanning the beam, the field of view can illuminate a one-dimensional or two-dimensional region of the retina to generate OCT data (see, for example, U.S. Patent 9,332,902; "Holoscopy–Holographic optical tomography" by D. Hillmann et al., Optics Letters, 36(13): 2390 2011; "High-speed three-dimensional human retinal imaging by line-field spectral domain optical coherence tomography" by Y. Nakamura et al., Optics Express, 15(12): 7103 2007; "Signal-to-noise ratio study of full-field Fourier domain optical coherence tomography" by Blazkiewicz et al., Applied Optics, 44(36): 7722 (2005)). In time-domain systems, the reference arm needs to have a tunable optical delay to generate interference. Balanced detection systems are typically used in TD-OCT and SS-OCT systems, while spectrometers are used at the detection port of SD-OCT systems. The invention described herein can be applied to any type of OCT system. Various aspects of this invention can be applied to any type of OCT system or other types of ophthalmic diagnostic systems and / or multiple ophthalmic diagnostic systems, including but not limited to fundus imaging systems, field-of-view testing equipment, and scanning laser polarimeters.

[0069] In Fourier domain optical coherence tomography (FD-OCT), each measurement is a real-valued spectral interferogram (Sj(k)). The real-valued spectral data typically undergoes several post-processing steps, including background subtraction and dispersion correction. The Fourier transform of the processed interferogram results in a complex-valued OCT signal output. The absolute value |Aj| of this complex OCT signal reveals the distribution of scattering intensity at different path lengths, and therefore scattering as a function of depth (z-direction) in the sample. Similarly, the phase... It can also be extracted from complex-valued OCT signals. The scattering distribution as a function of depth is called an axial scan (A-scan). A set of A-scans measured at adjacent locations in a sample produces a cross-sectional image (tomogram or B-scan) of the sample. The collection of B-scans collected at different lateral locations on the sample constitutes a data volume or cube. For a particular data volume, the term fast axis refers to the scanning direction along a single B-scan, while slow axis refers to the axis along which multiple B-scans are collected. The term "cluster scan" can refer to a single data unit or block of data generated by repeated collection at the same (or substantially the same) location (or region) for the purpose of analyzing motion contrast, which can be used to identify blood flow. A cluster scan can consist of multiple A-scans or B-scans collected at approximately the same location on the sample at relatively short time intervals. Because the scans in a cluster scan have the same region, the static structure remains relatively unchanged from scan to scan within the cluster scan, and the motion contrast between scans that meet predetermined criteria can be identified as blood flow. 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 diagonal of x and y, or in a circular or spiral pattern. B-scans can be in the xz dimension, but can be any cross-sectional image including the z dimension.

[0070] In OCT angiography or functional OCT, analytical algorithms can be applied to OCT data collected at the same or substantially the same sample location on the sample at different times (e.g., cluster scans) to analyze motion or flow (see, for example, U.S. Patent Publications 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 entirety). OCT systems can use any of a variety of OCT angiography processing algorithms (e.g., motion contrast algorithms) to identify blood flow. For example, motion contrast algorithms can be applied to intensity information derived from image data (intensity-based algorithms), phase information from image data (phase-based algorithms), or complex image data (complexity-based algorithms). A frontal image is a 2D projection of 3D OCT data (e.g., by averaging the intensity of each individual A-scan, such that each A-scan defines pixels in the 2D projection). Similarly, a frontal vascular system image is an image that displays motion contrast signals, where the data dimension corresponding to depth (e.g., along the z-direction of the A-scan) is typically displayed as a single representative value (e.g., a pixel in a 2D projected image) by summing or integrating all or isolated portions of the data (see, for example, U.S. Patent No. 7,301,644, which is incorporated herein by reference in its entirety). An OCT system providing angiographic imaging capabilities may be referred to as an OCT angiography (OCTA) system.

[0071] Figure 12 An example of a frontal vascular system image is shown. After processing the data using any motion contrast technique known in the art to highlight motion contrast, a range of pixels corresponding to a given tissue depth from the surface of the internal limiting membrane (ILM) in the retina can be summed to produce a frontal (e.g., orthographic) image of the vascular system.

[0072] Computing devices / systems

[0073] Figure 13 An example computer system (or computing device or computer apparatus) is illustrated. In some embodiments, one or more computer systems may provide the functionality described or illustrated herein and / or perform one or more steps of one or more methods described or illustrated herein. The computer system may take any suitable physical form. For example, the computer system may be an embedded computer system, a system-on-a-chip (SOC), a single-board computer system (SBC) (such as, for example, a computer module (COM) or system module (SOM)), a desktop computer system, a laptop or notebook computer system, a computer system grid, 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. Where appropriate, the computer system may reside in a cloud, which may include one or more cloud components within one or more networks.

[0074] In some implementations, the computer system may include a processor Cpnt1, memory Cpnt2, storage Cpnt3, input / output (I / O) interface Cpnt4, communication interface Cpnt5, and bus Cpnt6. The computer system may also optionally include a display Cpnt7, such as a computer monitor or screen.

[0075] Processor Cpnt1 includes hardware for executing instructions, such as those that constitute a computer program. For example, processor Cpnt1 may be a central processing unit (CPU) or a general-purpose graphics processing unit (GPGPU). Processor Cpnt1 may retrieve (or fetch) instructions from internal registers, internal caches, memory Cpnt2, or memory Cpnt3, decode and execute the instructions, and write one or more results to internal registers, internal caches, memory Cpnt2, or memory Cpnt3. In a particular embodiment, processor Cpnt1 may include one or more internal caches for data, instructions, or addresses. Processor Cpnt1 may include one or more instruction caches and one or more data caches, such as for maintaining data tables. Instructions in the instruction cache may be copies of instructions in memory Cpnt2 or memory Cpnt3, and the instruction cache may accelerate the retrieval of those instructions by processor Cpnt1. Processor Cpnt1 may include any suitable number of internal registers and may include one or more arithmetic logic units (ALUs). Processor Cpnt1 may be a multi-core processor; or may include one or more processors Cpnt1. Although this disclosure describes and illustrates particular processors, this disclosure considers any suitable processor.

[0076] Memory Cpnt2 may include primary memory for storing instructions for processor Cpnt1 to execute or maintain intermediate data during processing. For example, a computer system may load instructions or data (e.g., data tables) from memory Cpnt3 or from another source (such as another computer system) into memory Cpnt2. Processor Cpnt1 may load instructions and data from memory Cpnt2 into one or more internal registers or internal caches. To execute instructions, processor Cpnt1 may retrieve and decode instructions from internal registers or internal caches. During or after instruction execution, processor Cpnt1 may write one or more results (which may be intermediate or final results) to internal registers, internal caches, memory Cpnt2, or memory Cpnt3. Bus Cpnt6 may include one or more memory buses (each of which may include an address bus and a data bus) and may couple processor Cpnt1 to memory Cpnt2 and / or memory Cpnt3. Optionally, one or more memory management units (MMUs) facilitate data transfer between processor Cpnt1 and memory Cpnt2. Memory Cpnt2 (which can be fast volatile memory) may include random access memory (RAM), such as dynamic RAM (DRAM) or static RAM (SRAM). Memory Cpnt3 may include long-term or high-capacity memory for data or instructions. Memory Cpnt3 may be internal or external to the computer system and includes one or more of the following: disk drives (e.g., hard disk drives, HDDs or solid-state drives, SSDs), flash memory, ROM, EPROM, optical disks, magneto-optical disks, magnetic tape, Universal Serial Bus (USB) accessible drives, or other types of non-volatile memory.

[0077] The I / O interface Cpnt4 can be software, hardware, or a combination of both, and includes one or more interfaces (e.g., serial or parallel communication ports) for communicating with I / O devices, enabling communication with a person (e.g., a user). For example, I / O devices may include a keyboard, keypad, microphone, monitor, mouse, printer, scanner, speaker, camera, stylus, tablet, touchscreen, trackball, camcorder, another suitable I / O device, or a combination of two or more of these.

[0078] The communication interface Cpnt5 can 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 a wireless adapter for communicating with a wireless network. The communication interface Cpnt5 can provide communication with Wi-Fi networks, ad hoc networks, personal area networks (PANs), wireless PANs (e.g., Bluetooth WPANs), local area networks (LANs), wide area networks (WANs), metropolitan area networks (MANs), cellular telephone networks (such as GSM networks), the Internet, or combinations of two or more of these.

[0079] The Cpnt6 bus can provide communication links between the aforementioned components of a computing system. For example, the Cpnt6 bus may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an Infinite Bandwidth bus, a Low Pin Count (LPC) bus, a memory bus, a Micro Channel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCIe) bus, a Serial Advanced Technology Accessory (SATA) bus, a Video Electronics Standards Association Local (VLB) bus, or other suitable buses or combinations of two or more of them.

[0080] While 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.

[0081] In this document, where appropriate, one or more computer-readable non-volatile storage media may include one or more semiconductor-based or other integrated circuits (ICs) (such as, for example, field-programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs)), hard disk drives (HDDs), hybrid hard disk drives (HHDs), optical disks, optical disk drives (ODDs), magneto-optical disks, magneto-optical disk drives, floppy disks, floppy disk drives (FDDs), magnetic tape, solid-state drives (SSDs), RAM drives, secure digital cards or drives, any other suitable computer-readable non-volatile storage media, or any suitable combination of two or more of them. Where appropriate, computer-readable non-volatile storage media may be volatile, non-volatile, or a combination of volatile and non-volatile.

[0082] Although the invention has been described in conjunction with several specific embodiments, it will be apparent to those skilled in the art that many further substitutions, modifications, and variations will be apparent from the foregoing description. Therefore, the invention described herein is intended to cover all such alternatives, modifications, applications, and variations that may fall within the spirit and scope of the appended claims.

Claims

1. A non-contact lens adapter for imaging the anterior segment of the eye, comprising: One or more reflective surfaces are housed within the non-contact lens adapter, the non-contact lens adapter having a first end that can be attached to an ophthalmic imaging device and a second end that can be positioned in front of the eye without contacting the eye; The adapter is configured to receive an imaging beam from the ophthalmic imaging device and redirect the imaging beam, at least in part, through the pupil of the eye by using the one or more reflective surfaces, to target one or more ophthalmic anatomical features behind the iris of the eye, including or near the ciliary body of the eye. The imaging beam is redirected toward the eye at an angle of not less than 70 degrees relative to the optical center of the ophthalmic imaging device via the one or more reflective surfaces. Wherein, at least one selected reflective surface of the one or more reflective surfaces is curved along the optical center of the ophthalmic imaging device, and the curvature of the selected reflective surface keeps the focus at the same distance from the reflective surface on the x-axis and y-axis to reduce astigmatism of the imaging beam.

2. The adapter according to claim 1, wherein, One of the selected reflective surfaces extends around the interior of the non-contact lens adapter to allow the ophthalmic imaging device to image around the lens of the eye in 360 degrees.

3. The adapter according to claim 1 or 2, wherein, The one or more reflective surfaces include a plurality of peripheral reflective surfaces along the inner periphery of the non-contact lens adapter, each of the peripheral reflective surfaces having a different reflection angle selected for scanning above, below, nose, or temporal.

4. The adapter according to claim 1, further comprising: Central lens, wherein: The imaging beam passes through the peripheral region of the central lens to image the anterior segment of the eye; and The peripheral region is configured to focus the imaging beam onto the anterior segment of the eye, or to be combined with one or more reflective surfaces to correct aberrations.

5. The adapter according to claim 4, wherein, The central lens has a central region configured to receive a second beam of light directed toward the back of the eye from the ophthalmic imaging device, the second beam being a fixation beam or a second imaging beam, and wherein the central region is transparent to the second beam or focuses the second beam onto the back of the eye.

6. The adapter according to claim 1, wherein, The ophthalmic imaging device captures multiple images of the posterior portion of the eye through the central region of the non-contact lens adapter, while simultaneously imaging the anterior portion of the eye. Motion tracking information is generated based on the multiple images of the posterior portion of the eye, and motion correction is applied to the images of the anterior portion of the eye based on the generated motion tracking information.

7. The adapter according to claim 1, comprising: A second reflective surface receives the imaging beam from the ophthalmic imaging device and redirects the imaging beam to one or more reflective surfaces, which redirect the imaging beam to the eye.

8. The adapter according to claim 7, wherein, The second reflective surface can move laterally or around a tilt axis to scan multiple different areas in front of the eye.

9. The adapter according to claim 1, comprising: A first lens is configured to focus the imaging beam onto the front of the eye; as well as The second lens is configured to focus a second imaging beam from the ophthalmic imaging region along the optical center of the ophthalmic imaging region to image the posterior part of the eye, and the first lens and the second lens allow simultaneous imaging of the anterior and posterior parts of the eye.

10. The adapter according to claim 7, wherein: The one or more reflective surfaces include a first conical reflective surface; and The second reflective surface is a second conical reflective surface concentric within the first conical reflective surface.

11. The adapter according to claim 10, wherein: The second conical reflective surface is positioned along the optical center of the ophthalmic imaging device and provides an unobstructed optical path for the ophthalmic imaging device to image the posterior part of the eye through the central region of the second conical reflective surface.

12. The adapter according to claim 1, wherein: The ophthalmic anatomical features include the suspensory ligament; and The ophthalmic imaging device includes a data processing unit that processes imaging data and quantifies suspensory ligament measurements based on the imaging data. The imaging data includes one or more of the following: suspensory ligament density, suspensory ligament thickness, suspensory ligament length, suspensory ligament branch points, suspensory ligament branch count, and the location and number of contact points between the suspensory ligament and the lens or capsule.

13. The adapter according to claim 12, wherein, The data processing unit assigns a health grade value to the suspensory ligament based on one or more of the suspensory ligament metrics.

14. The adapter according to claim 1, wherein: The ophthalmic imaging device includes a data processing unit that processes imaging data and quantifies multiple anterior ophthalmic metrics based on images of the anterior segment of the eye. as well as Based on the aforementioned anterior ophthalmic measurements, the data processing unit assigns one or more diagnostic names to the eye, including suspensory ligament weakness, rupture, lens or intraocular lens subluxation or dislocation, suspensory ligament disease, dislocated intraocular lens, uveitis-glaucoma-hypopnea syndrome, ciliary body tumor, iris epithelial cyst, or posterior iris tumor.

15. An ophthalmic imaging system comprising the adapter according to any one of claims 1 to 14.

16. The ophthalmic imaging system according to claim 15, wherein: The ophthalmic imaging system is a fundus imager, an optical coherence tomography (OCT) system, or an OCT angiography system.

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