Method and ocular implant for transmission of nerve-stimulation light

Abstract

An improved prosthesis and method for stimulating vision nerves to obtain a vision sensation that is useful for the patient that has lost vision due to age-related macular degeneration (AMD) and retinitis pigmentosa (RP) and other diseases. The present invention utilizes infrared light to cause action potentials in the retinal nerves similar to those which result from rods and cones stimulated by visible light in healthy retinas. In some embodiments, the invention provides a pathway or “image pipe” for transmitting a stimulation pattern of infrared light from an external stimulator array through the eye and focusing the stimulation pattern of infrared light on the retina, especially the fovea. Some embodiments provide improved resolution down to a group of nerves, or even the individual nerve level, with sufficient energy density so as to cause a desired action potential.

What is claimed is: 
     
         1 . A method for treating a vision problem of an eye of a person, wherein the eye has an anteroposterior axis extending from the eye's anterior surface to the eye's retina, the method comprising:
 forming an optical path inside the person's eye, wherein the optical path is substantially transparent to at least some infrared wavelengths of light between about 1000 nm and about 1900 nm, wherein the optical path has a light-receiving anterior end closest to the eye's anterior surface and extends to a posterior end of the optical path;   securing the optical path to an anatomical feature of the eye;   generating an image signal representative of a scene;   generating a pulse-control signal representing pulse parameters that are based on the image signal;   generating a spatial pattern of pulsed infrared light signals based on the pulse-control signal; and   transmitting the spatial pattern of pulsed infrared light signals through the optical path, wherein the spatial pattern of pulsed infrared light signals triggers a nerve-action potential response in nerves of a retina layer of the eye of the person.   
     
     
         2 . The method of  claim 1 , wherein the transmitting of the spatial pattern includes transmitting more than half of infrared light having wavelengths between about 1800 and about 1900 nm that is incident on the anterior end. 
     
     
         3 . The method of  claim 1 , wherein the forming of the optical path includes forming at least a portion of the optical path with a biocompatible material that includes poly(methyl methacrylate) (PMMA). 
     
     
         4 . The method of  claim 1 , wherein the forming of the optical path includes forming the optical path in a material having substantially cylindrical-shaped sides from the anterior end to the posterior end, and wherein the posterior end of the material has a diameter substantially equal to a diameter of the anterior end of the material. 
     
     
         5 . The method of  claim 1 , wherein the forming of the optical path includes forming the optical path in a material that tapers from the anterior end to the posterior end, and wherein the posterior end of the material has a diameter that is larger than a diameter of the anterior end of the material. 
     
     
         6 . The method of  claim 1 , wherein the forming of the optical path includes shaping an anterior end of the optical path to form a lens, the method further comprising focusing, using the lens, the spatial pattern of pulsed infrared light signals on nerves of the retina. 
     
     
         7 . The method of  claim 1 , wherein the forming of the optical path includes enclosing a hollow portion of the optical path. 
     
     
         8 . The method of  claim 1 , wherein the forming of the optical path includes enclosing a hollow portion of the optical path and filling the hollow portion with an inert gas having a pressure of no more than about 1000 Torr. 
     
     
         9 . The method of  claim 1 , wherein the forming of the optical path includes enclosing a hollow portion of the optical path, filling the hollow portion with a gas, and shaping at least one end of the hollow portion to form a lens, the method further comprising focusing, using the lens, the spatial pattern of pulsed infrared light signals on nerves of the retina. 
     
     
         10 . The method of  claim 1 , wherein the anterior end of the ocular path extends through the anterior surface of the eye, replacing at least part of the eye's cornea, and wherein the securing of the optical path to the anatomical feature of the eye includes sealing the optical path securely to the sclera. 
     
     
         11 . The method of  claim 1 , wherein the anterior end of the ocular path is posterior to the eye's cornea. 
     
     
         12 . The method of  claim 1 , further comprising providing an indicia mark on the ocular path to facilitate detection of the eye's position. 
     
     
         13 . The method of  claim 1 , wherein the posterior end is within about two mm of the retina of the eye. 
     
     
         14 . A method for treating a vision problem of an eye of a person, wherein the eye has an anteroposterior axis extending from the eye's anterior surface to the eye's retina, the method comprising:
 providing an optical device having an optical path, wherein the optical path is substantially transparent to at least some infrared wavelengths of light between about 1810 nm and about 1900 nm, wherein the optical path has a light-receiving anterior end and a light-emitting posterior end;   implanting the optical device in the eye of the person such that the optical path is inside the person's eye and the anterior end is closest to the eye's anterior surface and the posterior end is closer to the retina than to the eye's anterior surface;   securing the optical device to an anatomical feature of the eye;   generating an image signal representative of a scene;   generating a pulse-control signal representing pulse parameters that are based on the image signal;   generating a spatial pattern of pulsed infrared light signals based on the pulse-control signal; and   transmitting the spatial pattern of pulsed infrared light signals through the optical path, wherein the spatial pattern of pulsed infrared light signals triggers a nerve-action potential response in nerves of a retina layer of the eye of the person.   
     
     
         15 . The method of  claim 14 , wherein the providing of the optical device includes forming the optical path in a material having substantially cylindrical-shaped sides from the anterior end to the posterior end, and wherein the posterior end of the material has a diameter substantially equal to a diameter of the anterior end of the material. 
     
     
         16 . The method of  claim 14 , wherein the providing of the optical device includes forming the optical path in a material that tapers from the anterior end to the posterior end, and wherein the posterior end of the material has a diameter that is larger than a diameter of the anterior end of the material. 
     
     
         17 . The method of  claim 14 , wherein the providing of the optical device includes shaping an anterior end of the optical path to form a lens, the method further comprising focusing, using the lens, the spatial pattern of pulsed infrared light signals on nerves of the retina. 
     
     
         18 . The method of  claim 14 , wherein the providing of the optical device includes enclosing a hollow portion of the optical path and filling the hollow portion with an inert gas having a pressure of no more than about 1000 Torr. 
     
     
         19 . The method of  claim 14 , wherein the implanting of the optical device includes locating the anterior end of the optical device such that the anterior end extends through the anterior surface of the eye, replacing at least part of the eye's cornea, and wherein the securing of the optical device to the anatomical feature of the eye includes sealing the optical device securely to the sclera. 
     
     
         20 . A method for treating a vision problem of an eye of a person, wherein the eye has an anteroposterior axis extending from the eye's anterior surface to the eye's retina, the method comprising:
 providing an optical device having an optical path, wherein the optical path is substantially transparent to at least some infrared wavelengths of light between about 1000 nm and about 1900 nm, wherein the optical path has a light-receiving anterior end and a light-emitting posterior end;   implanting the optical device in the eye of the person such that the optical path is inside the person's eye and the anterior end is closest to the eye's anterior surface and the posterior end is closer to the retina than to the eye's anterior surface;   securing the optical device to an anatomical feature of the eye;   generating an image signal representative of a scene;   generating a pulse-control signal representing pulse parameters that are based on the image signal;   generating a spatial pattern of pulsed infrared light signals based on the pulse-control signal; and   transmitting the spatial pattern of pulsed infrared light signals through the optical path, wherein the spatial pattern of pulsed infrared light signals triggers a nerve-action potential response in nerves of a retina layer of the eye of the person.