Corneal implants produced by irradiation of polymer films

• US 7,364,674 B1
• Filed: 07/23/2003
• Issued: 04/29/2008
• Est. Priority Date: 07/23/2002
• Status: Expired due to Fees

• Current Assignee: Advanced Optical Technologies, Inc.
• Original Assignee: Advanced Optical Technologies, Inc.
• Inventors: Hoover, Brian G.
• Primary Examiner(s): Vargot; Mathieu D.
• Application Number:
  US10/625,769
• Time in Patent Office: 1,742 Days
• Field of Search: 264/1.36, 264/1.37, 264/1.38, 264/488, 623/5.16
• US Class Current: 264/1.36
• CPC Class Codes: A61F 2/14 Eye parts, e.g. lenses, corneal implants; Implanting instruments specially adapted therefor; Artificial eyes
• CPC Class Codes: A61F 2/147 Implants to be inserted in the stroma for refractive correction, e.g. ring-like implants
• CPC Class Codes: A61L 2430/16 for reconstruction of eye parts, e.g. intraocular lens, cornea
• CPC Class Codes: A61L 27/16 obtained by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: B29D 11/023 Implants for natural eyes
• CPC Class Codes: C08L 33/12 Homopolymers or copolymers of methyl methacrylate

Abstract

The corneal implant of the current invention takes the general form of a thin, transparent, flexible, porous, biocompatible film of suitable polymer material. The implant is sufficiently porous, the porosity being imparted by the film being irradiated to produce tracks and the material in those tracks being subsequently removed through an etching process, to allow the adequate flow of gaseous and tissue fluid components through the film. Specific embodiments of the invention are achieved by the addition of features to the general form. The embodiment applicable to corneal reshaping features a surface relief pattern in the implant. The artificial iris embodiment features an imprinted partly to fully opaque or partially reflective annular iris pattern of selected inner and outer diameters.

Claims

1. A method of forming an optical device for surgical insertion into the cornea of an eye as a corneal implant, said method including the steps of:

a. providing a polymer film having first and second surfaces;

b. forming tracks in said polymer film by exposing said polymer film to a first source of radiation;

c. etching said tracks to form at least some pores in said polymer film which connect said first and second surfaces;

d. widening by etching at least some of said pores to dimensions large enough to permit the ingrowth of corneal tissue;

e. providing a first mask; and

f. reducing the transmission of at least a first portion of said polymer film to at least certain wavelengths of visible light by exposing said first portion of said polymer film to a second source of radiation through said first mask to produce the corneal implant

wherein said step of reducing said transmission is achieved by the step of forming a diffraction grating designed to reflect pre-selected wavelengths of visible light while transmitting other wavelengths.

2. A method of forming an optical device for surgical insertion into the cornea of an eye as a corneal implant, said method including the steps of:

a. providing a polymer film having first and second surfaces;

b. forming tracks in said polymer film by exposing said polymer film to a first source of radiation;

c. etching said tracks to form at least some pores in said polymer film which connect said first and second surfaces;

d. providing a first and a second mask;

e. reducing the transmission of at least a first portion of said polymer film to at least certain wavelengths of visible light by exposing said first portion to a second source of radiation through said first mask; and

f. forming surface relief in said polymer film by exposing a second portion of said polymer film to a third source of radiation through said second mask to produce the corneal implant.

3. The method of claim 2, wherein the step of reducing said transmission with said second source of radiation is achieved by using a source of accelerated ions to form a buried partly- to fully-opaque layer in said first portion of said polymer film.

4. The method of claim 2, wherein the step of forming said tracks with said first source of radiation is achieved by using a source of accelerated ions.

5. The method of claim 2, wherein the step of forming said tracks with said first source of radiation is achieved by using a source of x-rays.

6. The method of claim 2, wherein said step of forming said surface relief with said third source of radiation includes the step of forming within said polymer film a central disc and a concentric annulus of different thickness.

7. The method of claim 2, wherein the step of forming said surface relief with said third source of radiation includes the step of producing surface relief within said polymer film designed to correct for refractive error in an eye.

8. The method of claim 2, wherein said third source of radiation is selected from the group including optical lithography sources and ion beam sources.

9. The method of claim 6, wherein said step of reducing transmission is achieved by the step of exposing said concentric annulus to a source of accelerated ions to form a buried partly- to fully-opaque layer in said concentric annulus.

10. A method of forming an optical device for surgical insertion into the cornea of an eye as a corneal implant, said method including the steps of:

a. providing a polymer film having first and second surfaces;

b. forming tracks in said polymer film by exposing said polymer film to a first source of radiation;

c. etching said tracks to form at least some pores in said polymer film which connect said first and second surfaces;

d. widening by etching at least some of said pores to dimensions large enough to permit the ingrowth of corneal tissue;

e. providing a first and a second mask;

f. reducing the transmission of at least a first portion of said polymer film to at least certain wavelengths of visible light by exposing said first portion to a second source of radiation through said first mask; and

g. forming surface relief in said polymer film by exposing a second portion of said polymer film to a third source of radiation through said second mask to produce the corneal implant,

wherein said step of forming said surface relief with said third source of radiation includes the step of forming within said polymer film a central disc and a concentric annulus of different thickness and wherein said step of reducing transmission is achieved by the step of forming within said concentric annulus a diffraction grating designed to reflect pre-selected wavelengths of visible light while transmitting other wavelengths.