Methods and apparatus for accelerated orthokeratology

Abstract

An accelerated method of orthokeratology includes the steps of softening of the cornea with a softening agent, applying a mold to reshape the cornea to a desired anterior curvature, and rapidly restabilizing or “fixing” the corneal tissues so that the cornea retains its new configuration. A chemical softening agent, such as glutaric anhydride is applied to the cornea to soften the cornea, after which a specially designed mold of predetermined curvature and configuration is applied to the cornea. Slight downward pressure is applied to the mold for a predetermined period of time to re-shape the cornea. The mold is maintained in position while a stabilizing agent, such as a UV light source, is positioned above the mold. The stabilizing agent, i.e. UV light, is applied to the cornea for a predetermined time, wherein the stabilizing agent immediately restabilizes the corneal tissue so that the cornea immediately retains its shape upon removal of the mold. The stabilization process can also be used for patients having already undergone traditional orthokeratology to eliminate the need to continue wearing a retainer to maintain the shape of the cornea.

What is claimed is:  
     
         1 . A method of correcting refractive errors of the eye comprising the steps of: 
 destabilizing the corneal tissue of the eye so that the anterior curvature of the cornea can be reshaped from a first configuration to a second desired configuration;    shaping the softened cornea from the first configuration to the second desired configuration    by applying a mold to the cornea and applying pressure thereto, said mold having a predetermined posterior curvature and configuration which engages with the anterior curvature of the cornea; and    restabilizing the corneal tissues while the anterior curvature of the cornea is positioned in said second desired configuration.    
     
     
         2 . The method of    claim 1    wherein said step of destabilizing the corneal tissues comprises administering to the cornea a softening agent which is effective for destabilizing cross-linking between the collagen fibrils of the stroma of the cornea.  
     
     
         3 . The method of    claim 2    wherein said softening agent is selected from the group consisting of: anhydrides, acid chlorides, sulfonyl chlorides, sulfonic acids, and combinations thereof.  
     
     
         4 . The method of    claim 1    wherein said step of restabilizing the corneal tissues comprises exposing the corneal tissues to light energy.  
     
     
         5 . The method of    claim 1    wherein said step of restabilizing the corneal tissues comprises heating of the corneal tissues.  
     
     
         6 . The method of    claim 1    wherein heating of the corneal tissues comprises heating by means of laser thermal keratoplasty.  
     
     
         7 . The method of    claim 1    wherein said step of restabilizing the corneal tissues comprises administering to the cornea a chemical crosslinking agent which is effective for cross-linking between the collagen fibrils of the stroma of the cornea.  
     
     
         8 . The method of    claim 1    wherein said step of restabilizing the corneal tissues comprises exposing the corneal tissues to microwave energy.  
     
     
         9 . The method of    claim 4    wherein said step of restabilizing the corneal tissues comprises exposing the corneal tissues to visible light energy.  
     
     
         10 . The method of    claim 4    wherein said step of restabilizing the corneal tissues comprises exposing the corneal tissues to UV light energy.  
     
     
         11 . The method of    claim 4    further comprising the step of applying a photoinitiator chemical to the eye to rapidly initiate cross linking of the collagen matrix.  
     
     
         12 . The method of    claim 2    wherein said step of restabilizing the corneal tissues comprises exposing the corneal tissues to UV light energy.  
     
     
         13 . The method of    claim 12    further comprising the step of administering a photochemical initiator to the eye to rapidly initiate cross linking of the collagen matrix.  
     
     
         14 . The method of    claim 2    wherein said step of administering said chemical softening agent comprises the steps of positioning the lower rim of an annular staging device to the surface of the cornea so that the staging device encircles the area of the cornea to be treated, and administering the chemical softening agent into the interior of the staging device.  
     
     
         15 . The method of    claim 14    wherein the step of reshaping the cornea comprises positioning the mold within the staging device and applying downward pressure for a predetermined period of time.  
     
     
         16 . The method of    claim 15    wherein said mold is fabricated from a transparent and ultraviolet light transmittable material, and said step of restabilizing the corneal tissues comprises positioning an ultraviolet light source within the staging device on top of the mold and energizing the light source for a predetermined period of time whereby UV light passes through the mold to the corneal tissues.  
     
     
         17 . The method of    claim 14    wherein said step of restabilizing the corneal tissues comprises positioning an ultraviolet light source within the staging device and energizing the light source for a predetermined period of time whereby light is directed onto the corneal tissues.  
     
     
         18 . The method of    claim 16    further comprising the step of administering a photochemical activating agent to the cornea prior to exposing the cornea to said dosage of ultraviolet light.  
     
     
         19 . The method of    claim 17    further comprising the step of administering a photochemical activating agent to the cornea prior to exposing the cornea to said dosage of ultraviolet light.  
     
     
         20 . A method of correcting refractive errors of the eye comprising the steps of: 
 positioning the lower rim of an annular staging device to the surface of the cornea so that the staging device encircles the area of the cornea to be treated;    administering a chemical softening agent into the interior of the staging device wherein said chemical softening agent is effective for destabilizing cross-linking between the collagen fibrils of the stroma of the cornea so that the anterior curvature of the cornea can be reshaped from a first configuration to a second desired configuration;    reshaping the softened cornea from the first configuration to the second desired configuration by applying a mold to the cornea, said mold having a predetermined posterior curvature and configuration which engages with the anterior curvature of the cornea, said mold being positioned within the staging device and thereafter having downward pressure applied for a predetermined period of time to achieve said reshaping; and    restabilizing the corneal tissues while the anterior curvature of the cornea is positioned in said second desired configuration by exposing the corneal tissues to a predetermined dosage of ultraviolet light.    
     
     
         21 . The method of    claim 20    wherein said mold is fabricated from a transparent and ultraviolet light transmittable material, and said step of restabilizing the corneal tissues comprises positioning an ultraviolet light source within the staging device on top of the mold and energizing the light source for a predetermined period of time whereby light passes through the mold to the corneal tissues.  
     
     
         22 . A method of correcting refractive errors of the eye comprising the steps of: 
 reshaping the cornea from a first configuration to the second desired configuration by sequentially applying a series of orthotic contact lenses having predetermined curvatures and configurations intended to gradually render the cornea emmetropic; and    restabilizing the corneal tissues while the anterior curvature of the cornea is positioned in said second desired configuration by exposing the corneal tissues to a predetermined dosage of ultraviolet light.    
     
     
         23 . The method of    claim 22    wherein said step of stabilizing the corneal tissues comprises positioning the lower rim of an annular staging device to the surface of the cornea so that the staging device encircles the area of the cornea to be treated, positioning an ultraviolet light source within the staging device, and energizing the light source for a predetermined period of time whereby light is directed onto the corneal tissues.  
     
     
         24 . The method of    claim 22    further comprising the step of flushing the cornea with a mildly alkaline buffer solution prior to restabilizing the cornea.  
     
     
         25 . The method of    claim 24    wherein said alkaline buffer solution contains a chemical photoactivator to aid in stabilization of the corneal tissue.  
     
     
         26 . A staging device for use in treating the corneal tissues of the eye comprising a substantially cylindrical tube having upper and lower rim portions, said lower rim portion having an outer diameter of between about 10 mm and about 15 mm, said lower rim portion being positionable on the eye so as to encircle the area of the cornea to be treated.  
     
     
         27 . The staging device of    claim 26    wherein the lower rim portion is inwardly tapered at a predetermined angle so as to conform to the curved surface of the eye.  
     
     
         28 . The staging device of    claim 26    further comprising a flexible gasket on the lower rim portion of the tube, said gasket forming a flexible, water tight seal between the lower rim portion of the tube and the surface of the eye so as to prevent solutions administered within the staging device from leaking under the lower rim portion.  
     
     
         29 . The staging device of    claim 26    wherein the outer surface of the tube includes orientation markings to aid in proper placement of the staging device onto the eye.