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EP-4106610-B1 - OCT ZONULE IMAGING

EP4106610B1EP 4106610 B1EP4106610 B1EP 4106610B1EP-4106610-B1

Inventors

  • BELLO DELGADO, Simon
  • WANG, YINGJIAN
  • CARPENTER, AMANDA
  • ZHAO, Si Xi
  • ARIANTA, KABIR M.
  • BUMSTEAD, Jonathan

Dates

Publication Date
20260506
Application Date
20210218

Claims (15)

  1. A noncontact lens adapter (41) for imaging the anterior segment of an eye, comprising: one or more reflective surfaces (45) housed within the noncontact lens adapter, the noncontact lens adapter having a first end attachable to an ophthalmic imaging device (40) and a second end positionable in front of, and not touching, the eye; wherein the adapter is configured to receive an imaging beam (43) from the ophthalmic imaging device and to redirect the imaging beam, at least in part by use of the one or more reflective surfaces, through the pupil of the eye to target one or more ophthalmic anatomical features behind the iris of the eye and including, or proximate to, the ciliary body the of the eye; wherein the imaging beam is redirected by the one or more reflective surfaces toward the eye at an angle not smaller than 70 degrees relative to the optical center of the ophthalmic imaging device; wherein at least a select one of the one or more reflective surfaces is curved along the optical center of the ophthalmic imaging device, the curvature of the select one reflective surface maintaining 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. The adapter of claim 1, wherein the select one reflective surface extends around the interior of the noncontact lens adapter allowing the ophthalmic imaging device to image in 360 degrees around the crystalline lens of the eye.
  3. The adapter of any of claims 1 or 2, wherein the one or more reflective surfaces include a plurality of peripheral reflective surfaces along an inner perimeter of the noncontact lens adapter, each peripheral reflective surface having a different reflection angle selected to scan superiorly, inferiorly, nasally or temporally.
  4. The adapter of any of claims 1 to 3, further comprising: a central lens (49), wherein: the imaging beam passes through a 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, in combination with the one or more reflective surfaces, to correct for aberrations.
  5. The adapter of claim 4, wherein the central lens has a central region configured to receive a second beam from the ophthalmic imaging device directed to the posterior of the eye, 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 on the posterior of the eye.
  6. The adapter of any of claims 1 to 9, wherein the ophthalmic imaging device captures multiple images of the posterior of the eye through a central region of the noncontact lens adapter concurrently with the imaging of the anterior of the eye, generates motion tracking information based on the multiple images of the posterior of the eye, and applies motion correction to images of the anterior of the eye based on the generated motion tracking information.
  7. The adapter of any of claims 1 to 6, comprising: a second reflective surface (61) that receives the imaging beam from the ophthalmic imaging device and redirects the imaging beam to said one or more reflective surfaces, said one or more reflective surfaces redirecting the imaging beam to the eye.
  8. The adapter of claim 7, wherein the second reflective surface is moveable laterally or about a tilt axis to scan a plurality of different regions of the anterior of the eye.
  9. The adapter of any of claims 1 to 3 or 7, comprising: a first lens configured to focus the imaging beam on the anterior of the eye; and a second lens 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 of the eye, the first and second lenses permitting concurrent imaging of the anterior and posterior of the eye.
  10. The adapter of any of claim 1 to 3, 7 or 9, wherein: the one or more reflective surfaces includes a first conic reflective surface; and the second reflective surface is a second conic reflective surface concentric within the first conic reflective surface.
  11. The adapter of any of claims 1 to 3, 7, 9, or 10, wherein: the second conic reflective surface is positioned along the optical center of the ophthalmic imaging device, and provides an unimpeded optical path for the ophthalmic imaging image device to image the posterior of the eye through a central area of second conic reflective surface.
  12. The adapter of any of claims 1 to 11, wherein: the ophthalmic anatomical features include the zonules; and the ophthalmic imaging device includes a data processing unit processing imaging data and quantifying zonule metrics based on the imaging data including one or more of zonule density, zonule thickness, zonule length, zonule branching points, zonule branch count, and the location and number of zonule contact points with the crystalline lens or capsular bag.
  13. The adapter of claim 12, wherein the data processing unit assigns a health grade value to the zonules base on the one or more zonule metrics.
  14. The adapter of any of claim 1 to 13, wherein: the ophthalmic imaging device includes a data processing unit processing imaging data and quantifying a plurality of anterior ophthalmic metrics based on the images of the anterior segment of an eye; and based on the anterior ophthalmic metrics, the data processing unit assigns one or more diagnostic designation to the eye, including zonular weakness, dehiscence, lens or intraocular lens (IOL) subluxation or luxation, zonulopathy, misplaced IOL, uveitis-glaucoma-hyphema (UGH) syndrome, tumours of ciliary body, iris epithelial cysts, or tumours of the posterior iris.
  15. An ophthalmic imaging system, e.g. a fundus imager, an optical coherence tomography (OCT) system, or an OCT angiography system, comprising an adapter of any of claims 1 to 14.

Description

FIELD OF INVENTION The present invention is generally directed to optical coherence tomography (OCT) imaging of the anterior of an eye. More specifically, it is directed to OCT imaging immediately under the iris, and particularly to imaging the zonules of the eye. BACKGROUND FIG. 1 shows the anterior portion of an eye 11, including the cornea 13, anterior chamber 15, iris 17 whose center opening defines the pupil 19, the crystalline lens 21, the sclera 27 (the white of the eye), and the limbus 29 (the border of the cornea 13 and sclera 27). Also shown are zonules 23, which are fibrous structures that hold the crystalline lens 21 in place and allow for accommodation through contractions of the ciliary muscle (or ciliary body) 25. Imaging the zonules would be beneficial not only for disease diagnoses purpose, but for determining a current state (e.g., number, thickness variation, integrity, strength, etc.) of the zonule prior to a medical ophthalmic procedure, such as a procedure that may disturb the crystalline lens 21. Zonular imaging, however, is complicated due to the zonules 23 being located below/behind the iris 17, which blocks imaging light from directly reaching the zonules 23. Consequently, there is currently no convenient and reliable way to visualize or image the lens zonules 23. This limits understanding of the anatomy and pathological processes involving the zonules 23, which is important in diseases such as pseudo-exfoliation syndrome, pigment dispersion syndrome, Marfan syndrome, Weill-Marchesani syndrome, ectopia lentis, and trauma, amongst others. Furthermore, due to the lack of zonular imaging, zonular support during cataract surgery cannot be reliably evaluated pre-operatively. Often, zonular weakness and zonular dialysis (a deficiency of zonular support for the lenticular capsule, which is the membrane that surrounds the crystalline lens 21) is only appreciated intra-operatively during cataract surgery, and is a surprise to the surgeon. Because the surgeon is not able to plan his surgery accordingly, this may lead to complications such as posterior capsular rupture and retained nuclear fragments, which in turn may require additional surgeries and/or compromise the final surgical outcome. Most previous efforts to visualize the zonules center on ultrasound biomicroscopy (UBM), which uses ultrasound to determine the depth of tissue structures by directly measuring a time delay of returning ultrasound signals. UBM, however, is time consuming for a physician since it cannot be performed by a technician, and is uncomfortable for a patient. Furthermore, according to previous histopathological studies, the width of individual zonules is typically in the range of 10-30 µm, which is below the typical resolution limit of UBM, which is about 50 µm. Optical coherence tomography (OCT) provides higher resolution imaging, and is a less invasive imaging technology. Although not directed to zonular imaging, efforts to image the anterior of the eye at a steeper angle than typical using OCT have been put forth. For example U.S patents 9,517,006 and 9,936,868, both to Izatt et al., describe a system for imaging the limbal area of an eye. Izatt et al. use a custom contact lens configured to aim an OCT beam towards the limbus 29 of the eye 11. This approach, however, requires the OCT system to come in contact with the eye (e.g., the cornea), which complicates its use, and further does not provide for imaging below the iris. Izatt's approach seems to be geared to imaging the iridocorneal angle in the anterior chamber. Because of the refractive index mismatch between air and the anterior segment, the light is refracted, and it is difficult to direct a beam to measure the iridocorneal angle. Therefore, Izatt provides a contact lens to add media with similar refractive index between the optics and the cornea. The beam does not refract at the interface. This is evident from Izatt's figures. Document WO-A-2008/060 500 discloses a system for implementing ophthalmic photothermal treatment comprising a gonioscopic lens with reflective side·surfaces, which are optimized for directing the light at an acute angle towards the trabecular meshwork. It is an object of the present invention to provide a system for imaging the anterior of an eye below the iris at steep angles. It is another object of the present invention to provide an ophthalmic imaging system (e.g., a fundus imager or an OCT system) for imaging the anterior region of the eye immediately below the iris that avoids contact with the eye, e.g., does not contact the cornea or sclera of the eye. It is a further object of the present invention to provide a system for imaging the zonules of the eye with an ophthalmic imaging system. SUMMARY OF INVENTION The above objects are met in a system/device using or including a noncontact (contactless) lens adapter (e.g., an ophthalmic "cup") that may be fitted (e.g., coupled or attached) onto an existing ophthalmic imaging sys