Patent Publication Number: US-2005143717-A1

Title: Method of treatment of refractive errors using subepithelial or intrastromal corneal inlay with bonding coating

Description:
RELATED APPLICATIONS  
      This application is a continuation-in-part of U.S. patent application Ser. No. 10/406,558, filed Apr. 4, 2003 which claims the benefit of U.S. Provisional Application Ser. No. 60/449,617, filed Feb. 26, 2003, and is a continuation-in-part of U.S. patent application Ser. No. 10/356,730, filed Feb. 3, 2002 which is a continuation-in-part of U.S. patent application Ser. No. 09/843,141, filed Apr. 27, 2001, the entire contents of each of which are herein incorporated by reference. 
    
    
     FIELD OF THE INVENTION  
      The present invention relates to a method for treating refractive errors of a patient&#39;s eye. More specifically, an inlay is selected for correcting the patient&#39;s refractive error, implanted, and immobilized in proper position on the patient&#39;s cornea using a bonding compound, such as an organic coating.  
     BACKGROUND OF THE INVENTION  
      Conventional methods of treating refractive errors involve implanting a corrective lens by removing a portion or flap of one layer of the patient&#39;s cornea, such as the epithelium, implanting the lens on a second layer below the epithelium, and then waiting for the removed flap of the epithelium to grow back. Conventional methods also involve applying a material on the lens prior to implantation that promotes growth of the epithelium.  
      Presbyopia, which is blurred vision of close up objects, e.g. when reading, typically occurs due to aging of the eye. A conventional method for correcting the refractive error in a cornea is keratophakia, i.e., implantation of a lens inside the cornea. Keratophakia uses an implant which is placed into the cornea approximately equidistant from the exterior surface of the cornea and the interior surface. The procedure is usually done by first preparing a lens from corneal donor tissue or synthetic material using a cryo-lathe. The lens is implanted by removing a portion of the cornea with a device called a microkeratome, and the tissue is sutured back into place over the lens. However, there can be problems when microkeratomies are used for cutting the cornea. First, irregular keratectomies or perforations of the eye can result. Second, the recovery of vision can be rather prolonged.  
      Another surgical technique exists that uses a femtosecond laser to separate layers inside the stromal, at least two-thirds of the distance from the top surface of the cornea to the inside of the eye. An incision is made to access this area and a solid inlay is inserted to help correct myopia in the eye. By separating the layers in the bottom two-thirds of the stromal, it is difficult to access the separated area to insert the inlay and virtually impossible to change or modify the inlay without another extensive surgical procedure. This procedure requires making an incision which is parallel to the visual axis and is limited in the lateral direction by a maximum size of 0.3 mm to encase a relatively rigid inlay that forces the tissue in the lateral direction.  
      Additional surgical techniques exist that use ultraviolet light and short wavelength lasers to modify the shape of the cornea. For example, excimer lasers, such as those described in U.S. Pat. No. 4,840,175 to Peyman, which emit pulsed ultraviolet radiation, can be used to decompose or photoablate tissue in the live cornea so as to reshape the cornea.  
      Specifically, the Peyman patent discloses the laser surgical technique known as laser in situ keratomycosis (LASIK). In this technique, a portion of the front of the live cornea can be cut away in the form of a flap having a thickness of about 160 microns. This cut portion is removed from the live cornea to expose an inner surface of the cornea. A laser beam is then directed onto the exposed inner surface to ablate a desired amount of the inner surface up to 150-180 microns deep. The cut portion is reattached over the ablated portion of the cornea and assumes a shape conforming to that of the ablated portion. Additionally, in the Lasik procedure, a femtosecond laser can be used to cut and separate the flap.  
      Other conventional methods that have been employed specifically to correct presbyopia have been unsuccessful. Some of those methods include using an excimer laser to ablate the peripheral part of the cornea, expanding the sclera behind the limbus area of the cornea, implanting a plus lens inside the corneal stroma, using a multifocal intraocular lens after removal of the cataractous lens, bifocal glasses and bifocal contact lenses.  
      However, because only certain amount of cornea can be ablated without the remaining cornea becoming unstable or experiencing outbulging (ectasia), this technique is not especially effective in correcting very high myopia. That is, a typical cornea is on average about 500 microns thick. The laser ablation technique requires that at least about 250 microns of the corneal stroma remain after the ablation is completed so that instability and outbulging do not occur. Also, these conventional implants, while correcting a refractive error of the patient, also distort the normal vision of the patient.  
      Additional methods for correcting the refractive error in the eye include inserting an implant in-between layers of the cornea. Generally, this is achieved using several different methods. The first method involves inserting a ring between layers of the cornea, as described in U.S. Pat. No. 5,405,384 to Silvestrini. Typically, a dissector is inserted in the cornea and forms a channel therein. Once it is removed, a ring is then inserted into the channel to alter the curvature of the cornea. In the second method, a flap can be created similarly to the LASIK procedure and a lens can be inserted under the flap, as described in U.S. Pat. No. 6,102,946 to Nigam. The third method involves forming a pocket using an instrument, and inserting an implant into the pocket, as described in U.S. Pat. No. 4,655,774 to Choyce.  
      However, with the above described techniques, a knife or other mechanical instrument is generally used to form the channel, flap or pocket. Use of these instruments may result in damage or imprecision in the cut or formation of the desired area in which the implant is placed. Additionally, these conventional techniques do not include determination and testing of an appropriate implant for correcting a refractive error of a particular patient.  
      Prior methods for the treatment of presbyopia have been unsuccessful. One prior method involved implantation of a disc shaped inlay or lens over the central visual axis of the cornea. The disc inlay had a high index of refraction to correct presbyopia and/or hyperopia. However, because the disc covered the center area around the visual axis, the patient&#39;s farsighted vision was blurred by the inlay. Another prior method involved a ring shaped inlay implanted around the visual axis. The ring inlay had a lower index of refraction or an index of refraction that is the same as the cornea and therefor corrected myopic refractive errors instead of hyperopic or presbyopic error.  
      Therefore, there exists a need for an inlay and improved method of correcting refractive error that preserves the corneal flap and immobilizes the inlay in its proper position during the implantation process.  
     SUMMARY IF THE INVENTION  
      Accordingly, it is an object of the present invention to provide an improved method for modifying the cornea of an eye, particularly for correcting presbyopia.  
      Another object of the present invention is to provide a method for modifying the cornea of an eye that results in a precise separation between layers in the cornea.  
      Still another object of the present invention is to provide a method for modifying the cornea of an eye that allows for corrective measures that avoid or eliminate outbulging or instability in the cornea.  
      Yet another object of the present invention is to provide a method for modifying the cornea of an eye that avoids or eliminates most of the risks of damage due to use of knives or other mechanical instruments.  
      Another object of the present invention is to provide a method for treating a refractive error of the cornea by implanting a corrective inlay under the epithelium.  
      Still another object of the present invention is to provide a device for removing the epithelium to form a flap allowing an inlay to be implanted without damaging the epithelium.  
      Another object of the present invention is to provide an inlay that corrects presbyopia without distorting farsighted vision.  
      Yet another object of the present invention is to provide a method for selecting the appropriate inlay to correct a refractive error, such as presbyopia.  
      Still another object of the present invention is to provide a method for treating refractive errors that preserves the epithelium flap and immobilizes the corrective inlay in proper position with respect to the patient&#39;s visual axis.  
      The foregoing objects are basically attained by a method of treatment of refractive errors of an eye, the eye including a central visual axis and a cornea with a first corneal layer overlying a second corneal layer, comprising the steps of separating a first surface of the first corneal layer from a second surface of the second corneal layer, thereby forming a flap and exposing the second surface, implanting on the second surface an inlay adapted to correct a refractive error of the eye, coating a surface of the inlay with a compound that promotes bonding with the cornea, and replacing the flap over the inlay.  
      The foregoing objects are also attained by a method of treatment of refractive errors of an eye, the eye including a central visual axis and a cornea with a first corneal layer overlying a second corneal layer, comprising the steps of separating a first surface of the first corneal layer from a second surface of the second corneal layer, thereby exposing the second surface, implanting on the second surface an inlay adapted to correct a refractive error of the eye, coating a surface of the inlay after implanting the inlay with a compound that promotes bonding with the cornea, coating the exposed second surface adjacent the inlay with the compound, and drying the compound coating the inlay and the exposed second surface, thereby forming a drape over the inlay and bonding the inlay to the second surface.  
      Other objects, advantages, and salient features of the present invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses preferred embodiments of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      Referring to the drawings which form a part of this disclosure:  
       FIG. 1  illustrates a method of forming a pocket in the cornea of an eye, by irradiating the cornea with an ultrashort pulse laser, according to the preferred embodiment of the present invention;  
       FIG. 2  is an elevational front view of the eye and the pocket of  FIG. 1 ;  
       FIG. 3  is an elevational front view of a second embodiment of the invention wherein two pockets are formed by an ultrashort pulse laser;  
       FIG. 4  is an elevational front view of a third embodiment of the present invention wherein four pockets are formed by an ultrashort pulse laser;  
       FIG. 5  is an elevational front view of a fourth embodiment of the present invention wherein no central portion is left attached in a pocket formed by the ultrashort pulse laser;  
       FIG. 6  is an elevational front view of a fifth embodiment of the present invention wherein a needle is used to inject ocular material into a pocket formed by an ultrashort pulse laser;  
       FIG. 7  is a cross-sectional side view of the eye of  FIG. 6  with a contact lens placed on the external surface of the cornea to shape the ocular material;  
       FIG. 8  is a cross-sectional side view of a eye having a ring-shaped pocket formed in between layers of the cornea with a contact lens placed on the external surface of the cornea to shape the ocular material;  
       FIG. 9  is a front elevational view of a split ring ocular implant for use in the procedure shown in  FIGS. 1-4  and  19 - 24 ;  
       FIG. 10  is a front elevational view of a two part ocular implant for use in the procedure shown in  FIGS. 1-4  and  19 - 24 ;  
       FIG. 11  is a front elevational view of a three part ocular implant for use in the procedure shown in  FIGS. 1-4  and  19 - 24 ;  
       FIG. 12  is a side elevational view in cross-section of the ocular implant of  FIG. 9 , taken along lines  12 - 12 ;  
       FIG. 13  is a side elevational view in cross-section of the ocular implant of  FIG. 10 , taken along lines  13 - 13 ;  
       FIG. 14  is a side elevational view in cross-section of an arcuate ocular implant for use in the procedure shown in  FIGS. 1-4  and  19 - 24 ;  
       FIG. 15  is a side elevational view in cross-section of multiple ocular implants stacked on top of one another for use in the procedure shown in  FIGS. 1-4  and  19 - 24 ;  
       FIG. 16  is a side elevational view in cross-section of an ocular implant having a non-uniform thickness for use in the procedure shown in  FIGS. 1-4  and  19 - 24 ;  
       FIG. 17  is a front elevational view in cross-section of an ocular implant having four separate portions for use in the procedure shown in  FIGS. 1-4  and  19 - 24 ;  
       FIG. 18  is a front elevational view in cross-section of an ocular implant having two portions of different thickness for use in the procedure shown in  FIGS. 1-4  and  19 - 24 ;  
       FIG. 19  is a side elevational view in cross section similar to that shown in  FIG. 1  with the incision in the pocket open;  
       FIG. 20  is a side elevational view in cross section similar to that shown in  FIG. 19 , except that an annular or circular ocular implant has been introduced through the incision and between the internal surfaces;  
       FIG. 21  is a side elevational view in cross section of a probe irradiating a portion of the ocular material to reduce the volume of the portion;  
       FIG. 22  is a side elevational view in cross section of a probe irradiating a portion of the ocular material to increase the volume of the portion;  
       FIG. 23  is a side elevational view in cross section similar to that shown in  FIG. 19 , except that a portion of the external surface of the cornea has been ablated by a laser;  
       FIG. 24  is a side elevational view in cross section of the cornea with a flap formed thereon and a laser ablating a portion of the ocular material;  
       FIG. 25  is a side elevational view in cross section of an eye similar to that shown in  FIG. 20 , except that a flap has been formed on the surface of the cornea.  
       FIG. 26  is a side elevational view in cross section of the eye of  FIG. 25 , with the flap moved to expose an internal corneal surface;  
       FIG. 27 a  side elevational view in cross section of the eye of  FIG. 26 , with a laser ablating a portion of the exposed internal corneal surface;  
       FIG. 28  is a side elevational view in cross section of the eye of  FIG. 27 , with the flap replaced over the ablated internal corneal surface;  
       FIG. 29  is a top perspective view of a device for forming the flap of  FIGS. 25-28 ;  
       FIG. 30  is a top perspective view of a suction device for removing the flap of  FIGS. 25-28 ;  
       FIG. 31  is a method of forming a flap in the cornea of an eye, by cutting the cornea using a cutting tool;  
       FIG. 32  is a plan view of a semi-ring shaped inlay in accordance with an embodiment of the present invention, showing the inlay being implanted in the cornea underneath the epithelium;  
       FIG. 33  is an exploded side elevational view of the inlay illustrated in  FIG. 32 , showing the inlay being implanted on a corneal surface and under an epithelial flap;  
       FIG. 34  is a side elevational view taken in section along line  34 - 34  of  FIG. 32 ;  
       FIG. 35  is a side elevation view similar to  FIG. 34 , showing the use of an intraocular lens with the inlay;  
       FIG. 36  is a side elevational view of the inlay illustrated in  FIG. 32 , showing the inlay implanted on the corneal surface with the epithelial flap removed and the use of a laser with the inlay;  
       FIG. 37  is a side elevational view of an inlay in accordance with an embodiment of the present invention, showing the inlay having multiple layers and implanted under the epithelium;  
       FIG. 38  is a plan view of a ring-shaped inlay in accordance with an embodiment of the present invention, showing the inlay implanted in the cornea underneath the epithelium;  
       FIG. 39  is a side elevational view taken in section along line  39 - 39  of  FIG. 38 ;  
       FIG. 40  is a plan view of a semi-ring shaped inlay formed of a plurality of segments in accordance with an embodiment of the present invention, showing the inlay implanted in the cornea underneath the epithelium;  
       FIG. 41  is a side elevational view taken in section along line  41 - 41  of  FIG. 40 ;  
       FIG. 42  is a plan view of a ring-shaped inlay formed of a plurality of segments in accordance with an embodiment of the present invention, showing the inlay implanted in the cornea underneath the epithelium;  
       FIG. 43  is a side elevational view taken in section along line  43 - 43  of  FIG. 42 ;  
       FIG. 44  is a plan view of an inlay including two separate sections in accordance with an embodiment of the present invention, showing the inlay implanted in the cornea underneath the epithelium;  
       FIG. 45  is a side elevational view taken in section along line  45 - 45  of  FIG. 44 ;  
       FIG. 46  is a plan view of an inlay including two overlapping sections in accordance with an embodiment of the present invention, showing the inlay implanted in the cornea underneath the epithelium;  
       FIG. 47  is a side elevational view taken in section along line  47 - 47  of  FIG. 46 ;  
       FIG. 48  is a plan view of a rectangular inlay in accordance with an embodiment of the present invention, showing the inlay implanted in the cornea underneath the epithelium;  
       FIG. 49  is a side elevational view taken in section along line  49 - 49  of  FIG. 48 ;  
       FIG. 50  is a plan view of a circular inlay in accordance with an embodiment of the present invention, showing the inlay implanted in the cornea underneath the epithelium;  
       FIG. 51  is a side elevational view taken in section along line  51 - 51  of  FIG. 50 ;  
       FIG. 52  is a plan view of an inlay formed of a row of segments in accordance with an embodiment of the present invention, showing the inlay implanted in the cornea underneath the epithelium;  
       FIG. 53  is a side elevational view taken in section along line  53 - 53  of  FIG. 52 ;  
       FIG. 54  is a plan view of an inlay formed of multiple rings in accordance with an embodiment of the present invention, showing the inlay implanted in the cornea underneath the epithelium;  
       FIG. 55  is a side elevational view taken in section along line  55 - 55  of  FIG. 54 ;  
       FIG. 56  is a side elevational view in partial section of a suction device in accordance with the present invention, showing the suction device on the epithelium of the cornea prior to separation of an epithelial flap;  
       FIG. 57  is a side elevational view in partial section of the suction device illustrated in  FIG. 56 , showing the epithelial flap removed from the corneal surface by the suction device;  
       FIG. 58  is a plan view of the cornea illustrated in  FIG. 56 , showing markings on the cornea;  
       FIG. 59  is a top plan view of the suction device illustrated in  FIG. 56 ;  
       FIG. 60  is a bottom plan view of the suction device illustrated in  FIG. 56 ;  
       FIG. 61  is a side elevational view in partial section of an alternative suction device in accordance with the present invention, showing the suction device on the epithelium of the cornea prior to separation of an epithelial flap;  
       FIG. 62  is a side elevational view in partial section of the suction device illustrated in  FIG. 61 , showing the epithelial flap removed from the corneal surface by the suction device;  
       FIG. 63  is a bottom plan view of the suction device illustrated in  FIG. 61 ;  
       FIG. 64  is a top plan view of the suction device illustrated in  FIG. 61 ;  
       FIG. 65  is a side elevational view in section of an alternative suction device in accordance with the present invention, showing the suction device on the cornea prior to separation of a flap;  
       FIG. 66  is a top plan view of a plate of the suction device illustrated in  FIG. 65 ;  
       FIG. 67  is a top plan view of an alternative plate for the suction device illustrated in  FIG. 65 ;  
       FIG. 68  is a top plan view of an exemplary inlay in accordance with the present invention, showing a blend zone of the inlay;  
       FIG. 69  is a top plan view of a lens in accordance with the present invention, showing the lens supporting an exemplary inlay that is semi-ring shaped;  
       FIG. 70  is a top plan view similar to  FIG. 69  of a lens in accordance with the present invention, showing the lens supporting an exemplary inlay that is smaller than the inlay of  FIG. 69  and is semi-ring shaped;  
       FIG. 71  is a top plan view similar to  FIG. 69  of a lens in accordance with the present invention, showing the lens supporting an exemplary inlay that is larger that the inlay of  FIG. 69  and is semi-ring shaped;  
       FIG. 72  is a top plan view of a lens in accordance with the present invention, showing the lens supporting an exemplary inlay that is ring shaped;  
       FIG. 73  is a top plan view similar to  FIG. 72  of a lens in accordance with the present invention, showing the lens supporting an exemplary inlay that is smaller that the inlay of  FIG. 72  and is ring shaped;  
       FIG. 74  is a top plan view similar to  FIG. 72  of a lens in accordance with the present invention, showing the lens supporting an exemplary inlay that is larger that the inlay of  FIG. 72  and is ring shaped;  
       FIG. 75  is a top view of a lens in accordance with the present invention, showing the lens supporting an exemplary inlay that is substantially semi-circular in shape;  
       FIG. 76  is a top plan view of a lens in accordance with the present invention, showing the lens supporting an exemplary inlay that is substantially triangular in shape;  
       FIG. 77  is a top plan view of a lens in accordance with the present invention, showing the lens supporting an exemplary inlay that includes multiple rings;  
       FIG. 78  is a top plan view of a lens in accordance with the present invention, showing the lens supporting multiple exemplary inlays that are semi-ring shaped;  
       FIG. 79  is a top plan view of a lens in accordance with the present invention, showing markings on the lens;  
       FIG. 80  is a side elevational view in section of a lens in accordance with the present invention, showing the lens supporting an exemplary inlay in a recess of the lens;  
       FIG. 81  is a side elevational view in section of an inlay in accordance with the present invention, showing the lens supporting the inlay between two layers of the lens;  
       FIG. 82  is a side elevational view in section of an inlay in accordance with the present invention, showing the lens supporting the inlay on an outer surface of the lens;  
       FIG. 83  is an exploded side elevational view taken in section showing the flap of the patient&#39;s cornea being separated and lifted and the corrective inlay being implanted in accordance with the present invention;  
       FIG. 84  is a side elevational view taken in section similar to  FIG. 83 , showing the corrective inlay illustrated in  FIG. 83  positioned in the patient&#39;s cornea;  
       FIG. 85  is a side elevational view taken in section similar to  FIG. 84 , showing the application of a liquid coating on the corrective inlay;  
       FIG. 86  is a side elevational view taken in section similar to  FIG. 84 , showing the drying of the coating on the corrective inlay;  
       FIG. 87  is a side elevational view taken in section similar to  FIG. 84 , showing the flap replaced over the inlay and the coating dried on the inlay; and  
       FIG. 88  is an enlarged side elevational view in section of the corrective inlay illustrated in  FIG. 83 , showing a coating applied before implantation and substantially enclosing the inlay. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      As initially shown in  FIGS. 1, 2  and  19 - 24 , the refractive properties of eye  10  can be altered by using laser  12  to separate an inner portion of the cornea into first internal corneal surface  14  and second internal corneal surface  16 , creating internal corneal pocket  18  in the cornea  20  and then placing ocular material or an implant  22  in the pocket  18 . Additionally, the cornea can be shaped by using a second laser  24  to ablate a portion  26  of the surface  28  of the cornea  16 , or an external lens  29  to mold the ocular material.  
      To begin, the refractive error in the eye is measured using wavefront technology, as is known to one of ordinary skill in the art. For a more complete description of wavefront technology see U.S. Pat. No. 6,086,204 to Magnate, the entire contents of which is incorporated herein by reference. The refractive error measurements are transmitted to a computerized lathe (not shown) or other lens-shaping machine, where the shape of ocular material is determined using the information from the wavefront device. Alternatively, the ocular material  22  can be manufactured or shaped prior to the use of the wavefront technology and can be stored in a sterilized manner until that specific shape or size is needed.  
      Ocular material or inlay  22  has a first surface  21  and a second surface  23  and is porous to allow oxygen and nutrients to pass therethrough. Materials that are suitable for these purposes are preferably any polymer or hydrogel having about 50% water content; however, the water content can be any percentage desired. The ocular material may be formed from synthetic or organic material or a combination thereof. For example, the ocular material can be collagen combined with or without cells; a mixture of synthetic material and corneal stromal cells; silicone or silicone mixed with collagen; mucopolysacharide; chodrotin sulfate; elsatins; methylmetacrylate; hydrogel; any transparent material, such as polyprolidine, polyvinylpylidine, polyethylenoxide, etc.; or any deformable and/or porous polymer, which can change its shape with radiation after implantation. The collagen can be a semiliquid, a gel, human or other animal, or it can de derivatized.  
      Generally, ocular material  22  is preferably about 0.5 mm to 5 mm wide. The thickness is preferably about 5-2000 microns, and more preferably less than 200 microns. The inside edge can be thinner or thicker than the outside edge; for example, the inside edge can have a thickness of about 1-100 microns, while the outside edge has a thickness of about 20-3000 microns. However, the ocular material can have any thickness or configuration that would allow it to elevate or move any portion of surface  14  relative to surface  16 . The thickness and position of ocular material  22  generally defines the degree of correction.  
      Preferably, ocular material  22  is a liquid or a gel that can be injected through the surface of the cornea using an injection device  25 , such as a needle, without making a large incision or opening in the surface of the lens, as seen in  FIG. 6 . By injecting a gel into a pocket in this manner, the gel is confined to the corneal pocket  18  and will settle or move in the pocket in a predictable configuration or distribution. In other words, the gel will not flow through the layers of the cornea, but will rather stay inside the structure or confines of the pocket. The gel can be inserted into a pocket that encompasses the entire front of the cornea, or extend past the cornea and Bowman layer to the sclera. By extending the pocket past the Bowman layer, the portion of the cornea above the pocket would become loose. The injection of the gel would allow lifting of the Bowman layer, lifting up the entire front surface of the cornea, allowing the eye to be reshaped as desired. However, the gel can be injected or positioned into any size pocket desired and the pocket does not have to encompass the entire front of the cornea. Additionally, as described below, the ocular material does not necessarily need to be a gel in this process and may be a lens or any other desired material.  
      Furthermore, the ocular material  22  can include a silicone polymer which includes loose monomers that are responsive to light (both visible and invisible) within a certain wavelength range, such as the short ultraviolet wavelength range or the blue light wavelength range. In response to the light, the monomers become aggravated, and cross-linking occurs which increases the volume of the area of ocular material  22  or a portion of the ocular material, without substantially ablating the ocular material  22 , as well as fixing or hardening the ocular material.  
      The ocular material  22  can also include a polymer comprising a polycarbonate or acrylic material containing a dye or dyes manufactured, for example, by Centex Company. The dye or dyes absorb light within a certain wavelength range, such as the infrared wavelength range, which causes slight melting or reduction of the material or a portion of the ocular material, as well as solidification. This melting or reduction results in a decrease or flattening of the irradiated area of the ocular material  22 , and thus reduces the volume of that area for purposes discussed in more detail below, without substantially ablating the ocular material  22 .  
      See also U.S. application Ser. No. 09/532,516, filed Mar. 21, 2000 which is herein incorporated by reference, for a further discussion of swelling or shrinking of ocular material.  
      Ocular material  22  can also be a lens. When a lens, it can be any shape or sized desired. As seen in  FIGS. 6-15 , the lens is preferably substantially ring-shaped; but can be a circular or semicircular inlay. For example, unitary lenses  22   a - c  have a split  30  or have multiple portions that couple or fit together ( FIGS. 9-11 ), lens  22   b  is flat ( FIG. 13 ), lens  22   d  is arcuate ( FIG. 14 ), and lens  22   a  has tapered edges ( FIG. 12 ). Additionally, ocular material  22  may have any combination of these properties. When the lens has multiple portions, as seen in lenses  22   f  and  22   g , the portions can couple together, simply abut one another, they can lay near each other, not necessarily touching each other or the lens portions can be separated from each other ( FIGS. 17 and 18 ). Lens  22   b  can have multiple layers on top of each other ( FIG. 15 ), or lens  22   c  and  22   g  can have two sides with different thickness ( FIGS. 16 and 18 ), which would help to correct astigmatism. Additionally, the lens preferably allows light in the visible spectrum to pass therethrough and can have different or similar refractive properties to the refractive properties of the cornea, it can have pigmentation added thereto to change the color of the lens or it can be photochromatic. Furthermore, it is not necessary for the lens to have a hole or aperture therethrough. The lens can have a substantially planar surface or an arcuate surface with no holes or apertures therein, as seen specifically in  FIG. 5 .  
      As seen specifically in  FIGS. 1-5 , a laser  12  is aimed at an internal portion of the cornea, adjacent the external surface of the cornea of the eye and fired. Preferably, the laser is focused to create the pocket  18  in the first one-third of the cornea, and not in the back of the cornea. In other words, the pocket is preferably formed adjacent surface  28  or closer to surface  28  then to the interior or anterior chamber  11  of eye  10 . By forming the pocket in the first one-third of the cornea, the pocket or pockets may extend beyond the Bowmans layer and the cornea, to create a large pocket, which would allow raising of the entire front portion of the cornea, as described above. The laser preferably separates an internal area of the cornea offset from the main optical or visual axis  32  into first  14  and second  16  substantially ring-shaped internal surfaces to form the circular or ring-shaped corneal pocket  18 . First internal corneal surface  14  faces in a posterior direction of cornea  20  and the second internal corneal surface  16  faces in an anterior direction of the cornea  20 . The distance from first internal corneal surface  14  to the exterior corneal surface  28  is preferably a uniform thickness of about 10-250 microns, and more preferably about 80-100 microns, but can be any suitable thickness and does not necessarily need to be substantially uniform. A portion  34  of first and second surfaces  14  and  16  preferably remains attached to each other by an area located at the main optical axis  32 . However, the laser can form a pocket  18  of any suitable configuration, such as a pocket that is not attached at the main optical axis ( FIG. 5 ), two substantially similar pockets  18  and  18 ′( FIG. 3 ) or four pockets  18 ,  18 ′,  18 ′ and  18 ′″ ( FIG. 4 ). When multiple pockets are formed, preferably the pockets are separated by a portion  36 , which is an area where first and second surfaces  14  and  16  remain attached. However, the pocket or pockets may be any number, shape or size desired and they do not need to be circular or ring-shaped. Furthermore, a flap similar to the above-described pocket, and as described in U.S. patent application Ser. No. 09/758,263 can be formed using laser  12  or a cutting tool or knife  90  ( FIG. 31 ), such as a microkeratome, or any other device known in the art.  
      Laser  12  preferably is an ultrashort pulse laser, such as a femto, pico, or attosecond laser; but may be any light emitting device suitable for creating a pocket in the cornea as described above. The ultrashort pulse laser is positioned in front of the eye and is focused at the desired depth in the cornea and in the desired pocket configuration. Ultrashort pulse lasers are desired since they are high precision lasers that require less energy than conventional lasers to cut tissue and do not create “shock waves” that can damage surrounding structures. Cuts made by ultrashort pulse lasers can have very high surface quality with accuracy better than 10 microns, resulting in more precise cuts than those made with mechanical devices or other lasers. This type of accuracy results in less risks and complications than the procedures using other lasers or mechanical devices.  
      As seen in  FIGS. 2-5 , an incision or opening  38  is made in the surface  28  of the cornea to access pocket  18  or pockets  18 ′,  18 ″ and  18 ′″. Preferably, the incision  38  is made at the periphery of the pocket; however, it may be made anywhere desired that would allow access to the pocket  18 . Additionally, multiple incisions can be made that would allow access to different portions of pocket  18  or different pockets  18 ′,  18 ″ and  18 ′″. A carved instrument (not shown) can be inserted through the incision, which would dissect the pocket, if needed. A carved instrument is generally used to extend the pocket  18  past the cornea or Bowmans layer to the sclera as described above. However, a large incision may not be necessary, as in the case where a gel is inserted using a needle, as described above.  
      As seen in  FIGS. 19 and 20 , the ocular material  22  is then inserted through the incision  28  or any other opening by opening the incision using any device known in the art, such as spatula or microforceps or any other device. Preferably, when a lens is used, it has at least two separate portions  40  and  42  ( FIG. 10 ) or has a split  30  ( FIG. 9 ) that allow the ocular material  22  to be positioned or introduced around or at least partially encircling the main optical axis  32  or portion  34  and in between the first and second internal surfaces  14  and  16  that define the pocket  18 . However, as stated above the first and second surfaces  14  and  16  do not necessarily have to be attached at the main optical axis and in such a case, ocular material  22  is merely placed in pocket  18 .  
      As seen in  FIGS. 7 and 8 , when ocular material is injected or placed into pocket  18 , an external contact lens  29  can be placed on the external surface of the cornea, which would allow the gel to be shaped or redistributed and, thus, the cornea to be reshaped in any manner desired. The proper size and shape of the contact lens  29  is determined by the information received from the wavefront technology. Lens  29  is preferably a temporary lens that would allow light if the visible spectrum to pass therethrough. The contact lens back surface  31  forces the gel to distribute evenly until the topographically desired configuration is achieved. Additionally, the opening  38  may allow a small amount of gel to escape, if needed, to adjust the shape and size of the ocular-material  22 . Wave front technology can then be used to determine if the desired correction has been achieved, and if it has not the gel can be removed via an incision and the process repeated at a later time.  
      Once the ocular material is in place, the patient&#39;s eye can be monitored or measured and a laser, probe  31  or other heating device can be used to reduce the overall thickness of the ocular material  22 , if necessary. For instance, the ocular material  22  can initially be about 500 microns thick for ease of handling. Then, once the material  22  is positioned in the pocket  18  of the cornea, in the manner described above, the probe  40  (i.e., infrared light) can be directed to material  22  so as to reduce the overall thickness of material  22 , as desired. Hence, a 500 micron thick portion of the material can be reduced, for example, to about 100 microns or any suitable thickness by the heating device. It is noted that when the pulsed laser light is focused properly to a location within ocular material  22 , it can disrupt and thus shrink or melt ocular material  22  without the need of an absorbent dye. An example of such a laser is an ultrashort pulse laser, which emits nano-second pulses, pico-second pulses or femto-second pulses of laser light. Furthermore, laser light having a wavelength that is absorbed by water, or other types of energy such as microwave radiation, radio frequency radiation, or thermal energy, can be used to cause shrinkage in the lens.  
      As shown in  FIG. 21 , an area of the material is irradiated with energy L 1 , such as infrared light, laser light, microwave energy, radio frequency energy, or heat applied by a probe or laser  31 , to cause the area of the lens to shrink or, in other words, reduce in volume. This shrinkage occurs without damage to the ocular material or other portion of the cornea  20 . Accordingly, the shrinkage causes a change in the shape of the ocular material area, and thus changes the refractive power of the cornea  20  to further correct for the remaining vision disorder that was not fully corrected by the ocular material  22 . The ocular material can be irradiated directly through the cornea or through lens  29 .  
      Alternatively, the patient&#39;s vision can be monitored as the cornea  20  heals to determine if the size and shape of the ocular material  22  should be increased. The size or shape of the ocular material can be changed, and therefore the curvature of the cornea  20  can be changed without surgically opening the pocket  18 . That is, as discussed above, the ocular material  22  can include certain monomers which, when irradiated with light within a certain wavelength range (e.g., blue or ultraviolet light), become agitated and cross-link, which causes the ocular material  22  to increase in size at the area of the irradiation.  
      As shown in  FIG. 22 , an area of ocular material  22  is irradiated by probe  33  or laser light L 2 , which passes through the layer  21 . The laser light L 2  has a wavelength, such as long ultraviolet wavelength or light within the blue light spectrum, to aggravate the monomers, which causes a cross-linking effect that increases the volume of the ocular material  22  in the area being irradiated. Hence, as the thickness of the ocular material  22  increases, this increase thickness changes the curvature of the cornea as shown, thus changing the refractive power of the cornea to a degree necessary to correct the remainder of the vision disorder that was not corrected by the insertion of the ocular material  22 . The ocular material can be irradiated directly through the cornea or through lens  29 .  
      Furthermore, a chemical can be used to polymerize or solidify the ocular material, when the ocular material is a collegen solution. Preferably, the chemical is applied to the external surface of the cornea and passes through the cornea and into the pocket  18 , where it comes into contact with ocular material  22  and polymerizes the material. Preferably, the chemical used to polymerize the collegen solution is preferably about, 0.1 moler to 0.5 moler and more preferably about 0.2 moler to 0.4 moler of sodium persulphate diluted in a 0.02 moler phosphate buffer having a pH of about 8.0. However, the polymerizing chemical and the ocular material may be any suitable chemical and material known to one skilled in the art.  
      Furthermore, if necessary, the collegen solution can be depolymerized or returned to a gel or liquid state by applying glugaric anhydride in the same manner as described above for sodium persulphate. However, the depolymerization chemical can be any suitable chemical known in the art. Once the ocular material is depolymerized, the procedure can be repeated as often as desired. In other words, the refractive properties of the eye can be remeasured and reset and the material can be repolymerized as many times as desired until the correct refractive measurement is achieved.  
      To clean or wash the above chemicals from the eye, a disodium phosphate of about 0.02 molar and pH of 8.5 can be applied to the surface of the cornea.  
      Once the ocular material is in place and/or cross-linked or solidified as described above, the refractive properties of the eye can be remeasured using wavefront technology, and it can be determined if any refractive error remains in the eye. Generally, the refractive error is less than ±2.0 diopters sphere or astigmatism.  
      To reduce or eliminate this small refractive error, a second laser  44 , preferably an excimer laser, can then be aimed and fired at the external surface of the cornea  24 , ablating a portion  26  of the cornea, as seen in  FIG. 23 . Preferably, about 1-100 micron thickness is ablated, but any thickness that achieves the desired result can be ablated from the exterior surface of the cornea. The excimer laser can be applied either through the corneal epithelium or the epithelium can be reopened initially using diluted alcohol (less than 20% alcohol) or a brush. The second laser preferably ablates portion  26  of surface  22  that overlies the portion  34  attaches, but may ablate any portion desired.  
     Embodiment of FIGS.  25 - 28   
      In a further embodiment, a second flap  50  can be formed from the corneal epithelium on the surface  52  of the cornea  20 , a seen in  FIGS. 25-28  to reduce or eliminate irregularities in the healing of the cornea. Preferably, the flap is formed overlying portion  34  using a device  66  that has a sponge  68  thereon. As seen in  FIG. 29 , device  66  is a cylindrical tube having an opening  70  with sponge  68  inserted therein. Alcohol is fed through a hollow portion  69  that runs longitudinally along the interior of device  66 . When the alcohol saturates the sponge, the sponge can be applied to the surface of the cornea. The alcohol loosens the epithelium from the basement membrane, which allows removal of the epithelial layer. If it is desired to have the flap a least partially attached as shown in  FIGS. 25-28 , by portion  54 , a notch  72  can be formed along the edge of device  66 , thereby preventing the sponge from contacting potion  54 . Furthermore, the device  66  can have spikes or markers  74  at predetermined points on the edge of the device. For example, the markers can be at 90 degree or 180 degree intervals. The spikes can have a stain, such as gentian violet or any other suitable dye, applied thereto, so that the exact location and orientation of the flap is known. Therefore, when the flap is replaced or reapplied, it can be replaced in the exact or at least the substantially same position from which it was removed.  
      The second flap  50  is a relatively small flap that preferably at least partially overlies or is concentric about the visual axis or main optical axis  32  and can be attached to the cornea  20  by portion  54 . However, the flap can be formed on any portion of the cornea desired and in any suitable manner, such as with a knife or laser. It is noted, that the location of the flap does not necessarily need to be concentric about the main optical axis and can be at any location on the surface of the eye and may be any size desired.  
      The flap is preferably pealed or moved away from the surface of the cornea using a suction device  56  ( FIG. 30 ), but may be removed using any other device known in the art. As seen in  FIG. 30 , device  56  is substantially cylindrical with air holes  57  extending through top surface  80 . When suction device  56  is used, the flap is moved away from the cornea and remains attached to device  56 . Generally suction is applied and air travels through passageway  82 , which extends longitudinally along the interior of device  56 . When surface  80  is applied to the portion of the epithelium that has had alcohol applied thereto, a vacuum is formed in passageway  82  and flap  50  can be removed, as seen in  FIGS. 26 and 27 , exposing third and fourth internal corneal surfaces  58  and  60 . Surface  58  generally faces in a posterior direction and surface  60  generally faces in an anterior direction.  
      Once the flap is moved to expose surfaces  58  and  60 , an excimer laser  62 , as seen in  FIG. 27 , can be used to ablate a portion  64  of the cornea  20  to reduce or eliminate any remaining refractive error. Portion  64  is preferably a portion of the Bowman&#39;s layer or basement membrane, but can be any portion of the cornea desired. The flap  50  is then replaced and allowed to heal as seen in  FIG. 28 . The flap may simply be placed over the ablated portion and heal or it may be affixed thereto in any manner known in the art, such as by sutures or adhesive.  
      When performing the excimer laser procedures described above and shown in  FIGS. 23 and 27 , it is possible to simultaneously use wavefront technology or Adaptec optic technology to create a near perfect correction in the eye and to remove all corneal irregularities. By using this technique to correct vision, it is possible to achieve 20/10 vision in the patient&#39;s eye or better.  
      The patient can undergo the second laser ablation, as seen in FIGS.  23  or  FIG. 27 , either immediately after the insertion of the ocular implant or after a substantial time difference, such as days or weeks later, and any step or portion of the above procedure may be repeated to decrease the refractive error in the eye.  
      After the above procedures are preformed, and the ocular material is in place, if necessary, a flap  42  can be formed in the surface of the cornea of the eye, which would expose the ocular material  22  when removed or folded away, as seen in  FIG. 24 . Once the flap is removed or folded away, the ocular material can be irradiated and a portion  44  or the material  22  ablated by an excimer laser  46  and wavefront technology, as described above. Preferably, this technique is used on the pocket having no portion attached in the center, but may be used with any type of pocket, including the ring-shaped pocket.  
      Furthermore, at the end of the procedure or before the ablation of the surface of the cornea, topical agents, such as an anti-inflammatory, antibiotics and/or an antiprolifrative agent, such as mitomycin or thiotepa, at very low concentrations can be used over the ablated area to prevent subsequent haze formation. The mitomycin concentration is preferably about 0.005-0.05% and more preferably about 0.02%. A short-term bandage contact lens may also be used to protect the cornea. The short term contact lens specifically protects the portion of the cornea that has flap  50  formed thereon, but also can protect the cornea after any of the above steps in this procedure.  
     Embodiments of FIGS.  32 - 64   
      Referring to  FIGS. 32-62 , treatment of a refractive error such as presbyopia, is also accomplished by implanting a biocompatible inlay  100 , such as a lens or other ocular material, under the epithelium  102  of the cornea  104 . In general, a surface  105  of epithelium  102 , such as a flap, is separated from a corneal surface  108  of cornea  104  so that inlay  100  can be implanted between the surface of the epithelium  102  and the corneal surface  108 . This treatment method maintains the integrity of the cornea  104  by only cutting into the epithelium  102 , allowing the inlay  100  to be easily implanted and removed, and reducing scarring. Also, by not discarding the portion of the epithelium that has been removed, irregularities in the healing of the cornea that often occur during regrowth of the epithelium  102  are minimized. Although this treatment method is preferably used to correct presbyopia, the method can be employed to correct any refractive error including hyperopia, myopia and astigmatism.  
      Preferably, the surface  105  of epithelium  102  that is separated from corneal surface  108  forms an epithelial flap  106 . Inlay  100  can then be implanted on a corneal surface  108  exposed by the separation of epithelial flap  106 . Epithelial flap  106  is replaced in tact over inlay  100  and corneal surface  108  with epithelial flap  106  conforming to the shape and curvature of inlay  100 . Epithelial flap  106  preferably remains attached to epithelium  102  at a peripheral area of the flap, forming hinge  110 , as seen in  FIG. 33 . However, flap  106  can be completely detached from epithelium  102  and then replaced over inlay  100  and corneal surface  108  or flap  106  can be attached at any portion of the cornea desired, such as at the main optical axis. Alternatively, instead of a flap  106 , a pocket can be formed between epithelium  102  and corneal surface  108  that receives inlay  100  at an opening of the pocket. Although it is preferable to form the flap  106 , or pocket, in the epithelium  102 , the flap  106  can be formed in other layers of cornea  104  including the Bowman&#39;s layer  162  or the stroma  164 , such as is done in the LASIK procedure.  
       FIGS. 32-55  illustrate various examples of inlay  100 , including inlays  100   a - 100   j , respectively. Each inlay has a particular shape and curvature to provide correction for a particular type of refractive error. Generally, inlays  100   a - 100   j , are small with a diameter ranging between 1-7 mm, and preferably 3-4 mm. Diffractive technology allows the inlays to be made very thin with a thickness ranging between 0.1-200 microns. The thin nature of inlays  100   a - 100   j  facilitates implantation of each inlay  100  under epithelium  102 . Micro perforations  112  can be included in inlays  100 , as seen in  FIG. 32 , for example (illustrating inlay  100   a ), to facilitate fluid or nutrient flow through the inlays, which reduces or eliminates cloudiness or opacification or potential necrosis caused by malnutrition. To correct a variety of refractive errors, inlays  100   a - 100   j  can have plus, minus or astigmatic power or any combination thereof such as to create a bifocal effect.  
      Also, inlays  100   a - 100   j  are similar to ocular material  22  (see  FIGS. 9-18 ) and likewise can have a variety of shapes, a uniform or varied thickness, single or multiple layers, or multiple sections that are either integral or separate, and can be either concentric or eccentric with the visual axis  114 . The shaped and curvature of each inlay is predetermined based on the refractive error or errors that require correction.  
      Each inlay  100   a - 100   j  preferably includes a blend zone or area  116  which eliminates square edges to provide a gradual change or slope between each inlay and corneal surface  108 , thereby reducing discomfort to the patient. Generally, blend zone  116  surrounds the peripheral edges of each inlay, as seen in  FIG. 32 , for example (illustrating inlay  100   a ).  
      As seen in  FIGS. 32-37 , inlay  100   a  is substantially semi-circular or semi-ring shaped. Ends  118  of inlay  100   a  are preferably tapered, as seen in  FIG. 32 . Inlay  100   a  is preferably concentric with visual axis  114  of cornea  104  and leaves uncovered an annular area  120  surrounding visual axis  114 . Optionally, micro perforations  112  are disposed along inlay  100   a.    
      Once inlay  100   a  is implanted on corneal surface  108 , as seen in  FIG. 33 , flap  106  is replaced over implant  100   a  and corneal surface  108 , as seen in  FIG. 34 , so that posterior surface  122  of flap  106  directly overlies the front surface  124  of inlay  100   a . Flap  106  conforms to the shape of inlay  100   a . The difference in shape, including the difference in curvature, between inlay  100   a  and cornea  104  provides either plus power for correcting farsightedness, minus power for correcting nearsightedness, or an astigmatic power for correcting an astigmatism. For example, as seen in  FIG. 34 , in cross-section, inlay  100   a  includes first and second curved portions  126  and  128  which each define a curvature about their respective central axis  130  that is substantially greater than the curvature of cornea  104 , as defined about visual axis  114 . This difference in curvature provides plus and minus correction of the refractive error.  
      Preferably, the refractive index of inlay  100   a  is the same as the refractive index of cornea  104 , thereby relying on the difference in curvature and shape between inlay  100   a  and cornea  104  to provide the appropriate refractive correction. However, inlay  100   a  can have a different index of refraction than cornea  104 . Also, as seen in  FIG. 37 , inlay  100   a  can include multiple layers  132  and  134  each having either the same or different index of refraction from cornea  104 .  
      As seen in  FIGS. 38-45 , inlays  100   b - 100   e  each provide correction of refractive errors based on their curvature and shape, similar to inlay  100   a . Each inlay  100   b - 100   e  is preferably concentrically disposed with respect to visual axis  114  on corneal surface  108 . Inlay  100   b  is substantially ring-shaped (see  FIG. 38 ) and includes curved portions  136  in cross section similar to curved portions  126  and  128  of inlay  100   a  (see  FIG. 39 ). Inlays  100   c  and  100   d  are formed of a plurality of segments  138  each generally circular in shape, with inlay  100   c  having a semi-ring shape (see  FIG. 40 ) and inlay  100   d  having a ring shape (see  FIG. 42 ). In cross section, segments  138  define a plurality undulations on both the front and back surfaces  124  and  125  of inlays  100   c  and  100   d  (see  FIGS. 41 and 43 ). Inlay  100   e  includes two separate sections  140  and  142  (see  FIG. 44 ) each similar in curvature and shape to inlay  100   a  (see  FIG. 45 ). As seen in  FIGS. 39, 41 ,  43  and  45 , epithelial flap  106  conforms to the shape and curvature of each inlay  100   b - 100   e  including curved portions  136  of inlay  100   b , the undulations of surfaces  124  and  125  of inlays  100   c  and  100   d , and the curved sections  140  and  142  of inlay  100   e.    
      As seen  FIGS. 46-47 , inlay  100   f  also provides correction of refractive errors in the same manner as described above with respect to inlays  100   a    100   e , and also preferably includes multiple sections  144  and  146  integrally attached to form inlay  100   f . Specifically, the first and second sections  144  and  146  are generally circular in shape with first section  144  having a smaller diameter than second section  146  (see  FIG. 46 ). Only first section  144  is concentric with visual axis  114 , as seen in  FIG. 47 , however, either section can be concentric or eccentric with respect to axis  114 . First section  144  overlies second section  146  with each section preferably providing correction for a different refractive error by the curvature and shape of each section  144  and  146 . For example, first section  144  corrects myopia or hyperopia and second section  146  corrects for presbyopia. However, the shape and curvature of each section  144  and  146  can be changed to provide correction for any refractive error. Epithelial flap  106  conforms to the shape of each section  144  and  146  including the more convex curvature of section  144  as compared to section  146 .  
      As seen in  FIGS. 48-53 , inlays  100   g - 100   i  provide correction of refractive errors in the same manner as described for inlays  100   a - 100   f  and are preferably eccentric to visual axis  114  but located in annular area  120  defined around axis  114  (see  FIGS. 49, 51  and  53 ). Inlay  100   g  is non-circular and generally rectangular in shape, as seen in  FIG. 48 . However, inlay  100   g  can be any polygonal non-circular shape. Epithelial flap  106  conforms to the shape of inlay  100   g  including the substantially square cross sectional shape and blend zone  116  of inlay  100   g , as seen in  FIG. 49 . Inlay  100   h  is generally disc shaped, as seen in  FIG. 50 . As seen in  FIG. 51 , epithelial flap  106  conforms to the shape of inlay  100   h  including the flat curvature and blend zone  116  of inlay  100   h . Inlay  100   i  is formed of a row of segments  148  similar to segments  138  of inlays  100   c  and  100   d . Epithelial flap  106  conforms to the shaped of each segment, as seen in  FIG. 53 .  
      As seen in  FIGS. 54-55 , inlay  100   j  is formed of first, second and third circular sections  150 ,  152  and  154 . First section  150  is generally disc shaped with second section  152  surrounding first section  150  to form a first ring  156  of inlay  100   j  and third section  154  surrounding second section  152  to form a second ring  158 . First, second and third sections  150 ,  152  and  154  preferably provide correction for different refractive errors in an alternating manner. For example, first section  150  has a flatter curvature than second section  152  or first ring  156 , as seen in  FIG. 55 , to provide correction for myopia, second section  152  has a more convex curvature to provide correction for presbyopia and hyperopia, and third section  154  or second ring  158  has a flatter curvature to provide correction for myopia. Additional sections or rings can be added to inlay  100   j  to continue providing refractive error correction in an alternating manner. As seen in  FIG. 55 , epithelial flap  106  conforms to the variations in curvature of each section  150 ,  152  and  154 , i.e. flatter versus more convex curvature.  
      When treating presbyopia, the inlay  100 , such as inlay  100   a - 100   j , preferably does not cover annular area  120  around visual axis  114  of cornea  104 , such as seen in  FIGS. 32, 38 ,  42  and  44 , for example. This uncovered area  120  allows the patient to see through the uncovered annular area  120  for normal far vision and see through the inlay for correction of presbyopia when the patient reads. As a result of the uncovered annular area  120 , the presbyopia of the patient is corrected without distorting the patient&#39;s normal far vision.  
      Correction of presbyopia and/or hyperopia is provided in two ways. The first way is by the index of refraction of the inlay  100 , as described above. Specifically, by using an inlay  100 , such as one of inlays  100   a - 100   j , that has a higher index of refraction than the cornea  104 , plus correction for presbyopia is provided. The difference in the index of refractions between the inlay and the cornea corrects the refractive error due to the inlay  100  bending light differently, i.e. refracts closer to the cornea, than the cornea. Examples of materials used to form the inlay that have an index of refraction different or higher than the cornea include silicone, methacrylate, hydrogel, hilafilcon, or mixture of various synthetic and/or organic polymers.  
      The second way of correcting presbyopia and/or hyperopia is to provide inlay  100  with a curvature that is different than the curvature of cornea  104 . Preferably, inlay  100  has at least a portion with radial curvature that is smaller than the radial curvature of cornea  104 , thereby correcting presbyopia and/or hyperopia by bending more light closer to the cornea. The smaller the radial curvature of inlay  100  with respect to cornea  104  the more correction is provided for presbyopia and/or hyperopia, as is well known in the art.  
      As described in U.S. Pat. No. 6,436,092 to Peyman, which is herein incorporated by reference, a laser L can alternatively be employed to ablate inlays  100   a - 100   j  or the surrounding area of the cornea prior to replacing epithelial flap  106 , as seen in  FIG. 36  for example, or inlays  100   a - 100   j  can be adjusted after epithelial flap  106  is replaced using light, such as infrared light, when additional correction of a refractive error is required, as described in U.S. patent application Ser. No. 09/494,248, which is herein incorporated by reference. Also, an intraocular lens IOL can be used in combination with inlays  100   a - 100   j , as seen in  FIG. 35 , to create a telescopic effect.  
      Referring to  FIGS. 56-60 , epithelial flap  106  is formed by applying suction to a portion of the epithelium  102  using a suction device  200  to separate the epithelium surface  105  from corneal surface  108 . As seen in  FIGS. 56-60 , suction device  200  is generally a cylindrical chamber  202  having first and second opposing walls  204  and  206  and defining an internal area  208 . Suction device  200  operates in generally the same manner as suction device  66 , as seen in  FIGS. 31 . First wall  204  of suction device  200  includes aeration holes  210  (see  FIG. 59 ) and an engagement surface  212  that contacts and supports the epithelial flap  106  once separated from corneal surface  108 , as seen in  FIG. 57 . At second wall  204 , suction  214  is applied through internal area  208  by a suctioning mechanism such as a vacuum. Additionally, markers or spikes  216  similar to markers  74  described above with respect to suction device  66 , are included at first wall  204  to mark the exact location and orientation of flap  106 , particularly with respect to visual axis  114 . Chamber  202  is preferably transparent allowing visual observation of markers  216  as well as the corresponding marks  218  left on epithelial flap and cornea  108 , as seen in  FIG. 58 .  
      Once suction  214  is applied to epithelium  102  at the desired location of flap  106 , i.e., preferably centered with respect to visual axis  114 , a cutting device  220  is employed to dissect flap  106  from corneal surface  108 . The operator can observe as cutting device  220  through transparent chamber  202  as device  220  is dissecting flap  106 . Cutting device  220  is preferably a spatula but can be any cutting device known in the art, such as a knife or microkeratome. Due to the suction  214  applied through internal area  208  and aeration holes  210  of chamber  202 , flap  106  will lift and separate from corneal surface  108  and abut engagement surface  212 . Alcohol can also be used to facilitate this process. Flap  106  remains engaged with surface  212  of chamber  202  keeping the flap  106  in tact. Once the inlay  100 , which is preselected, such as from inlays  100   a - 100   j , is implanted on corneal surface  108 , flap  106  can be replaced over the inlay  100  and corneal surface  108 . By looking through transparent chamber  202 , markers  216  can be matched with marks  218  on the corneal surface to ensure proper positioning of flap  106 . This procedure maintains the integrity of the epithelium and avoids the need to regrow the epithelium over the implanted inlay and thus avoids irregularities that often result therefrom.  
      Referring to  FIGS. 61-64 , an alternative suction device  300  is disclosed that employs both a chamber  302  for supporting the epithelial flap  106  and a holding device  304  for holding a portion of the eye surrounding the flap  106 . Chamber  302  is similar to chamber  202  except that chamber  302  is generally rectangular in shape. Chamber  302  is preferably transparent including opposite first and second walls  306  and  308  with the first wall  306  including aeration holes  310  and an engagement surface  312 . Holding device  304  is preferably a tubular ring  314  having aeration holes  316  to engage and hold the eye around flap  106  while dissecting flap  106 . An automatic cutting device  318  is preferably used, such as a vibrating spatula, that dissects the epithelial flap inside of tubular ring  314  and under chamber  302 . Epithelial flap  106  will lift and separate from corneal surface  108  and engage engagement surface  312 , as seen in  FIG. 62 , in the same manner as described above with respect to device  200  using suction  322 . Also, as with device  200 , the transparent nature of the chamber  302  allows the operator to observe cutting device  318  as flap  106  is being dissected and match markings  320  of chamber  302  with marks of the corneal surface.  
      Referring to  FIGS. 65-67 , another alternative device  400  for creating a flap in cornea  104  in accordance with the present invention generally includes a chamber  402 , a suction device  404 , a plate  406  and a vibrating device  408 . Chamber  402  includes first and second opposite ends  410  and  412  and an interior area  414  that supports plate  406  at first end  410 . Vibrating device  408  is coupled to plate  406  and vibrates plate  406  within chamber interior area  414 . Specifically, vibrating device  408  includes an arm  416  that extends through chamber second end  412 , into interior area  414  and attaches to plate  406  in any conventional manner. Vibrating device  408  is preferably any conventional vibrating mechanism known in the art and/or other arts, such as vibrating toothbrushes and shavers.  
      Chamber interior area  414  supports plate  406  by an inner flange  416  of chamber  402  extending into interior area  414  at chamber first end  410  so that plate  406  can freely vibrate via vibrating device  408 . However, any conventional coupling mechanism can be employed to support plate  406  within interior area  414 , as long as plate  406  is allowed to vibrate. First end  410  of chamber  402  is open thereby exposing a cornea engagement surface  418  outside of interior area  414  for engaging corneal surface  108 . Opposite cornea engagement surface  418  is vibrating device attachment surface  420  of plate  406  for engaging arm  416  of vibrating device  408  as described above.  
      As seen in  FIG. 66 , plate  406  is substantially circular and forms a flap  426  in generally the same manner as described above having a circular shape corresponding to the shape of plate  406 . Plate  406  includes a plurality of aeration holes  422  in fluid communication with a suction  424  of suction device  404  that extends through chamber second end  412  and into interior area  414 . Although plate  406  is preferably circular in shape, plate  406  can have any desired shape. For example, plate  406 ′ shows an alternative shape for plate  406  as substantially semi-circular with aeration holes  422 ′.  
      Flap  426  is similar to flap  106  described above and is formed using device  400  by placing chamber first end  410  and plate  406  on the epithelium  102  of cornea  104 . Application of suction to chamber interior area  414  via suction device  404  draws flap  426  into engagement with cornea engagement surface  418  of plate  406  via aeration holes  422 . Vibrating plate  406  via vibrating device  418  separates flap  426  from cornea  104  allowing implantation of an inlay, as described above. Alternatively, a vibrating spatula or a knife can be employed to separate flap  426  once plate  406  engages flap  426 . Although it is preferable to create a flap  426 , device  400  can also be used to create a pocket (not shown) in cornea  104 . Also, flap  426  is preferably formed by separating the epithelium  102  from cornea  104 , however, flap  426  can be created in any layer of the cornea  104 .  
      As seen in  FIG. 68 , blend zone  116  of inlays  100   a - 100   j  is painted with a light absorbing pigment ( FIG. 68  showing only inlay  100   a ). The pigmented blend zone  116  prevents glare that is often a result of implantation of the inlay, such as inlays  100   a - 100   j , being implanted in the cornea.  
      To evaluate and select the most appropriate inlay  100  for a particular patient, a lens  500 , such as a contact lens, is preferably used that supports the inlay  100  selected from a group of inlays  100  to be tested on the patient. The groups of inlays include, for example, inlays  100   a - 100   j , as seen in  FIGS. 32, 38 ,  40 ,  42 ,  44 ,  46 ,  48 ,  50 ,  52 ,  54 , and inlays  100   k - 100   u  shown in  FIGS. 69-78 . A variety of inlays  100  which have different shapes and sizes, and which can also vary in distance from the central visual axis  114  of the cornea  104  can be used with contact lens  500  to test for refractive errors and determine the appropriate inlay  100  for a particular patient. Inlays  100   a - 100   u  are examples of inlays  100  that can be used with contact lens  500 . Once an inlay  100  is selected from the group of inlays, the inlay is coupled to contact lens  500  and placed on the patient&#39;s cornea  104  to determine whether that selected inlay is appropriate for correcting the refractive error of the patient. Specifically, contact lens  500  with inlay  100  coupled thereto is oriented over the central visual axis  114 , so that inlay is disposed adjacent annular area  120  surrounding visual axis  114  and so that only contact lens  500  covers annular area  120 . As described above, the patient is able to see through annular area  120  for normal far vision and see through inlay  100  for reading and correction of the patient&#39;s presbyopia. Either a single contact lens  500  supporting a selected inlay  100  one at a time or multiple contact lenses  500  each supporting a different selected inlay  100  can be used to evaluate the appropriate inlay  100  for the patient.  
      As seen in  FIGS. 69-78 , each inlay  100   k - 100   u  is supported by a contact lens  500  and placed on the patient&#39;s cornea  104  for testing. As seen in  FIGS. 69-71 , each of inlays  100   k - 100   o  is substantially semi-ring shaped, similar to inlay  100   a . Each inlay  100   k - 100   o  is generally concentric with visual axis  114  and located adjacent annular area  120 . Inlay  1001  has a smaller radial curvature that inlay  100   k  and is disposed closer to visual axis  114  than inlay  100   k . Conversely, inlay  100   o  has a larger radial curvature than inlay  100   k  and is disposed further away from axis  114 .  
      As seen in  FIGS. 72-74 , each of inlays  100   m - 100   p  is substantially ring-shaped, similar to inlay  10   b . Each inlay  100   m - 100   p  is generally concentric with visual axis  114  and extends around annular area  120  leaving annular area  120  uncovered by the inlay. Inlay  100   n  has a smaller radius than inlay  100   m  and is thus closer to visual axis  114  than inlay  100   m . Inlay  100   p  has a larger radius than inlay  100   m  and is further away from visual axis  114  than inlay  100   m.    
      As seen in  FIG. 75 , inlay  100   q  is substantially semi-circular shaped and is oriented adjacent annular area  120 . Inlay  100   r  is substantially triangular in shape and disposed adjacent visual axis  114 , as seen in  FIG. 76 . Inlay  100   s  is similar to inlay  100   j , and includes multiple rings  556  and  558  concentric with visual axis  114  and surrounding annular area  120 . As seen in  FIG. 78 , two inlays  100   t  and  100   u  are combined on contact lens  500 . Inlay  100   u  is semi-ring shaped and has a smaller radial curvature than inlay  100   t  which is also semi-ring shaped. Thus inlay  100   u  is disposed adjacent annular area  120  and closer to visual axis  114  with inlay  100   t  being spaced from inlay  100   u.    
      Contact lens  500  is made of a flexible compatible material that is synthetic, organic or a combination thereof. Contact lens  500  is marked, as seen in  FIG. 79 , to correspond to die markings of the cornea. This allows contact lens  500  and the selected inlay to be precisely centered on cornea  104  with respect to visual axis  114 .  
      Inlay  100  is coupled to contact lens  500  in one of three ways. In the first way, inlay  100  is placed within a recess or window  502  of contact lens  500 , as seen in  FIG. 80 . Recess  502  is open at an outer surface  504  of lens  500  opposite an inner surface  506  for engaging the cornea  104 . Recess  502  extends into contact lens  500  and includes an inlay supporting surface  508  upon which the selected inlay  100  rests. If the selected inlay  100  is not appropriate for the patient, that inlay can be removed from recess  502  and another selected inlay can be placed in the recess  502 . Thus recess  502  allows multiple inlays to be individually received therein and tested on the patient, and removed without having to remove lens  500  from the patient&#39;s cornea, thereby allowing testing of various inlays  100  until the appropriate one for the patient is found.  
      The second way to couple the selected inlay  100  with contact lens  500  is to implant inlay  100  between first and second surfaces  510  and  512  of lens  500 . Preferably, first and second surfaces  510  and  512  are disposed on first and second layers  514  and  516 , as seen in  FIG. 81 , so that inlay  100  is embedded inbetween the layers  514  and  516 . The third way to couple the selected inlay  100  with lens  500  is to attaching inlay  100  to outer surface  504  using a bioadhesive.  
      A patient with presbyopia is examined, and corrected for far vision if required and the degree of presbyopia is determined. An inlay  100  is selected from the group of inlays and coupled to lens  500 , as described above. Lens  500  with the selected inlay  100  is centered on the patient&#39;s cornea  104  to determine whether that selected inlay is appropriate for the patient. This process is repeated with different inlays coupled to lens  500  until the appropriate inlay is found for the patient. The patient will choose the best add or inlay embedded in the contact lens  500  that the patient prefers and that provides the near vision or correction for presbyopia without producing too much of glare or blurring of the far vision. For example, depending on the amount of correction required, some patients may prefer an inlay  100  that is closer to visual axis  114 , such as inlays  1001  or  100   o , thereby providing more correction for presbyopia. If correction for far vision is not required, the contact lenses  500  tested on the patient would be those that would not cover the annular region around the visual axis  114 . Then the selected contact lens is positioned on the central visual axis on the patient&#39;s cornea. Then the position of the add or lens on the cornea is marked with the dye markings  520  with respect to visual axis  114  (see  FIG. 79 ) for subsequent implantation of the selected inlay. The selected inlay  100  will be implanted in the manner described above in the same orientation as the tested contact lens using the markings, such as at the same distance from the visual axis  114 .  
     Embodiment of FIGS.  83 - 88   
      Referring to  FIGS. 83-88 , an inlay  600  is implanted in a patient&#39;s cornea  604  to correct refractive errors in the same manner as described above with respect to inlay  100  and cornea  104  of the embodiments of  FIGS. 32-64 , except an immobilizing coating  610  is applied to inlay  600  to ensure that the proper position of inlay  600  with respect to the visual axis is maintained. Coating  610  can be applied to inlay  600  during the implantation process. As with the embodiments of  FIGS. 32-64 , cornea flap  606  is preserved, instead of removing flap  606  and waiting for flap  606  to grow back over inlay  600 . Inlay  600  can be implanted in any layer of the cornea including the epithelium or stroma.  
      Inlay  600  may be any shape such as disc ( FIG. 83 ), ring ( FIG. 38 ), or semi-ring ( FIG. 32 ) shaped, or any of the shapes of inlays  100   a - 100   j . Inlay  600  is formed in the same manner as inlay  100  to correct refractive errors, such as myopia, hyperopia, and presbyopia. Also, as with inlay  100 , inlay  600  can be made very thin, such as 0.1-200 microns, using diffractive technology. Inlay  600  can include pores like pores  112  of inlay  100  ( FIG. 32 ) to facilitate the flow of nutrients between the corneal layers of cornea  604  and through inlay  600 . The pores can have a size of 0.6-50 micrometers, and preferably 1-2 micrometers. Inlay  600  may be formed of organic materials, such as collagen, laminin, or vitronectin, or synthetic materials, such as silicon, hydrogel or hilaficon, or a mixture of organic and synthetic materials. Rather than single focality, inlay  600  can be formed with the characteristics of a diffractive beam splitter to generate multifocality, i.e., far, middle, and near vision.  
      As seen in  FIG. 83 , inlay  600  has a front surface  620 , an opposite back surface  622 , and side surfaces  624  extending therebetween. Flap  606  can be formed in a layer  602  of cornea  604  in the same manner as described for the embodiments of  FIGS. 1-82 . Layer  602  may be the epithelium of cornea  604  or any other layer, such as the stroma, of cornea  604 . Flap  606  is lifted and pulled back, thereby exposing corneal surface  608 . Inlay  600  is then implanted in cornea  604  by placing inlay  600  on exposed corneal surface  608  with back surface  622  resting on corneal surface  608 , as seen in  FIG. 84 .  
      Inlay  600  is then positioned or centered with respect to visual axis  614  in the same manner as described above with respect to the embodiments of  FIGS. 32-64 . Inlay  600  can be ablated to adjust correction of the refractive error in the same manner as described with respect to inlay  100 . Coating  610  is then applied to inlay  600  and exposed corneal surface  608  adjacent inlay  600 . More specifically, coating  610  is applied to front and side surfaces  620  and  622  of inlay and areas  626  of exposed cornea surface  608  adjacent inlay  600 , as seen in  FIG. 86 . Coating  610  can also be applied to back surface  622 . Coating  610  has adhesive or bonding properties to immobilize and bond inlay  600  to exposed corneal surface  608 . Coating  610  can be any organic polymer or compound with bonding properties such as, fibronectin, collagen, vitronectin, or polysaccande. Coating  610  is applied in liquid form on inlay  600 , as seen in  FIG. 85 . Any excess coating can be absorbed by a sponge.  
      Coating  610  is then dried for a short period of time, such as 1 second-5 minutes, crosslinking coating  610  to form a drape over inlay  600  and areas  626  of cornea surface  626 , as seen in  FIG. 86 , thereby immobilizing inlay  600  in proper position on corneal surface  608 . Coating  610  may be dried by exposure to ultraviolet light or air  616 . Once dried, coating  610  may have a thickness of 0.01-5 microns.  
      Flap  606  is then replaced over inlay  600  and exposed cornea surface  608  with inlay  600  being immobilized in proper position. By not removing flap  606 , flap  606  is preserved and growth of a new flap is not required.  
      Alternatively, coating  610  can be a membrane  630  that substantially encloses all or part of inlay  600 , as seen in  FIG. 88 . Membrane  630  may be pre-formed prior to implantation. Membrane  630  may be formed of amniotic material.  
      While preferred embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.