Eye model for wide field fundus imaging
The present invention contemplates an infant eye model for wide field retinal imaging by implementing nominal physical parameters and optical characteristics found in scientific literature and by simulating retinal features and details found in real eye images. The present invention also contemplates implementing a corneal model with a translucent plastic to mimic image haze and 1 st Purkinje reflection. The present invention also contemplates implementing a birefringent layer to the lens posterior surface to simulate 4 th Purkinje reflection and its brightness variation. The present invention further contemplates implementing a photo-realistic retinal hemisphere shell to provide retinal details and demonstrate retinopathy associated with retinal diseases.
1. An eye model having a central axis, configured for wide field retinal imaging, comprising:
a cornea model comprising a translucent plastic and having a convex anterior surface configured to provide a first Purkinje image;
a lens model comprising a glass or plastic convex-convex lens configured to provide a fourth Purkinje image;
an iris model disposed between the lens model and the cornea model; and
a retinal model comprising a retinal shell having a concave retinal surface and a photographic retina image disposed on the concave retinal surface, the eye model being configured to provide a viewable field of at least 80 degrees on the retinal surface measured relative to the central axis,
wherein a space between the lens model and the retinal model is filled with a transparent liquid, and
wherein at least one of the cornea model and the lens model comprises a birefringent material.
2. The eye model of claim 1 , wherein said cornea model is a cornea model of an infant wherein the convex anterior surface has a nominal radius of curvature of about 6 mm or is a cornea model of an adult wherein the convex anterior surface has a nominal radius of curvature of about 8 mm.
3. The eye model of claim 1 , wherein said shell and said photographic retinal image are hemispherical and both have a nominal diameter of about 15 mm corresponding to an infant eye or both have a nominal diameter of about 22 mm corresponding to an adult eye.
4. The eye model of claim 1 , wherein said retinal shell is made from a thermal formable material.
5. The eye model of claim 1 , wherein said transparent liquid is water.
6. The eye model of claim 1 , wherein said cornea model is made of PMMA.
7. The eye model of claim 1 , wherein said cornea model is made of lightly translucent acrylic.
8. The eye model of claim 1 , wherein the photographic retinal image is an inkjet image.
9. An eye model having a central axis, configured for wide field retinal imaging, comprising:
an integrated cornea-lens model comprising a convex anterior surface; and
a retinal model comprising a retinal shell having a concave retinal surface and a photographic retinal image disposed on the concave retinal surface,
the eye model being configured to provide a viewable field of at least 80 degrees on the retinal surface measured relative to the central axis,
a watertight enclosure enabling said eye model to be filled with a transparent liquid,
wherein the cornea-lens model comprises a birefringent material.
10. The eye model of claim 9 , wherein said anterior surface of said cornea-lens model has a nominal radius of curvature of approximately 6 mm or has a nominal radius of curvature of approximately 8 mm.
11. The eye model of claim 9 , wherein said retinal shell is a hemisphere with a nominal diameter of approximately 15 mm or 22 mm.
12. The eye model of claim 9 , wherein said photographic retinal image includes retinal details of a diseased retina.
13. A method for creating an eye model, comprising the steps of:
providing a cornea model comprising a convex anterior surface configured to provide a first Purkinje image;
providing a lens model comprising a convex-convex lens configured to provide a fourth Purkinje image;
providing an iris model disposed between the lens model and the cornea model; and
producing a retinal model by printing a photographic image of a retina on a thermally-deformable material and, after the step of printing the photographic image, deforming said thermally-deformable material such that retinal model comprises a retinal shell having the photographic image disposed on a curved surface, and
positioning the retinal shell such that the photographic image can be viewed through the cornea model, the lens model and the iris model.
14. The method of claim 13 , further comprising a step of acquiring the photographic image by imaging a human retina using an ophthalmic camera.
15. The method of claim 13 , wherein said photographic image of said retina covers an angle of at least 80 degrees in all angular directions relative to a central axis of the eye model.
16. The method of claim 13 , wherein said step of deforming is achieved using a vacuum forming molding technique.
17. The method of claim 13 , further comprising generating the photographic retinal image by forming a composite image of a plurality of retinal photographic images.