WO2003099170A1

WO2003099170A1 - Corneal inlay having alignment protrusions

Info

Publication number: WO2003099170A1
Application number: PCT/US2003/016425
Authority: WO
Inventors: Gholam Peyman
Original assignee: Minu, L.L.C.
Priority date: 2002-05-24
Filing date: 2003-05-23
Publication date: 2003-12-04
Also published as: AU2003247410A1

Abstract

An inlay (320) adapted to be positioned on the cornea (12) of an eye for correcting refractive error in the eye. The inlay includes a first surface for placement on an exposed surface of the cornea (12) and a second surface, opposite the first surface, which is adapted to be exposed to light. At least one protrusion (322, 324) extends from at least one of the first and second surfaces and is adapted to be inserted into at least one aperture (314b, 316b) in the cornea (12), the protrusion (322, 324) having a width that is substantially smaller than a radius of the inlay.

Description

CORNEAL INLAY HAVING ALIGNMENT PROTRUSIONS

Field of the Invention

[OOOl] The present invention relates to a method and apparatus for correcting the refractive error in the cornea of the eye using an intracorneal inlay. In particular, the cornea is modified by forming a flap in the cornea and exposing a portion of the stroma underlying the flap. At least one opening is formed in the exposed stroma or the flap, either before or after the flap is formed and an intracorneal inlay having at least one protrusion is inserted under the flap with the protrusion or protrusions being inserted into the opening or respective openings, thus affixing the inlay in place and preventing movement of the inlay relative to the cornea.

Background of the Invention

[0002] A normal emetropic eye includes a cornea, a lens and a retina. The cornea and lens of a normal eye cooperatively focus light entering the eye from a far point, i.e., infinity, onto the retina. However, an eye can have a disorder known as ametropia, which is the inability of the lens and cornea to focus the far point correctly on the retina.

Typical types of ametropia are myopia, hypermetropia or hyperopia, and astigmatism.

[0003] A myopic eye has either an axial length that is longer than that of a normal emetropic eye, or a cornea or lens having a refractive power stronger than that of the cornea and lens of an emetropic eye. This stronger refractive power causes the far point to be projected in front of the retina.

[0004] Conversely, a hypermetropic or hyperopic eye has an axial length shorter than that of a normal emetropic eye, or a lens or cornea having a refractive power less than that of a lens and cornea of an emetropic eye. This lesser refractive power causes the far point to be focused behind the retina.

[0005] An eye suffering from astigmatism has a defect in the lens or shape of the cornea. Therefore, an astigmatic eye is incapable of sharply focusing images on the retina. [0006] Optical methods are known which involve the placement of lenses in front of the eye, for example, in the form of eyeglasses or contact lenses, to correct vision disorders. A common method of correcting myopia is to place a "minus" or concave lens in front of the eye to decrease the refractive power of the cornea and lens. In a similar manner, hypermetropic or hyperopic conditions can be corrected to a certain degree by placing a "plus" or convex lens in front of the eye to increase the refractive power of the cornea and lens. Lenses having other shapes can be used to correct astigmatism. The concave, convex or other shaped lenses are typically configured in the form of glasses or contact lenses.

[0007] Although these optical methods can be used to correct vision in eyes suffering from low myopia, or in eyes suffering from hypermetropic, hyperopic or astigmatic conditions which are not very severe, these methods are ineffective in correcting vision in eyes suffering from severe forms of ametropia. [0008] However, surgical techniques exist for correcting these more severe forms of ametropia to a certain degree. For example, in a technique known as myopic keratomileusis, a microkeratome is used to cut away a portion of the front of the live cornea from the main section of the live cornea. The cut portion of the cornea is frozen and placed in a cryolathe where it is cut and reshaped. Altering the shape of the cut portion of the cornea changes the refractive power of this cut portion, which thus affects the location at which light entering the cut portion of the cornea is focused. The reshaped cut portion of the cornea is then thawed and reattached to the main portion of the live cornea. Hence, it is intended that the reshaped cornea will change the position at which the light entering the eye through the cut portion is focused, so that hopefully the light is focused directly on the retina, thus remedying the ametropic condition. [0009] The myopic keratomileusis technique is known to be effective in curing myopic conditions within a high range. However, the technique is impractical because it employs very complicated and time consuming freezing, cutting and thawing processes. [0010] Keratophakia is another known surgical technique for correcting severe ametropic conditions of the eye by altering the shape of the eye's cornea. In this technique an artificial, organic or synthetic lens is implanted inside the cornea to thereby alter the shape of the cornea and thus change its refractive power. Accordingly, as with the myopic keratomileusis technique, it is desirable that the shape of the cornea be altered to a degree that allows light entering the eye to be focused correctly on the retina. [0011] However, the conventional lenses and methods for type of correction are often impractical for correcting astigmatic error in the eye. Since an irregular shaped cornea or eye generally causes astigmatic error, to correct astigmatism an implanted lens must be a specific asymmetrical shape that would negate the irregularity. Often is difficult to properly position and maintain the lens in the correct orientation relative to the cornea, thereby making the procedure difficult and time consuming. [0012] Examples of known techniques for modifying corneal curvature, such as those discussed above, are described in U.S. Patent No. 4,994,058 to Raven et al., U.S. Patent No. 4,718,418 to L'Esperance, U.S. Patent No. 5,336,261 to Barrett et al., and a publication by Jose I. Barraquer, M.D. entitled "Keratomileusis and Keratophakia in the Surgical Correction of Aphakia". The entire contents of each of these patents are incorporated herein by reference.

[0013] Surgical techniques involving the use of ultraviolet and shorter wavelength lasers to modify the shape of the cornea also are known. For example, excimer lasers, such as those described in U.S. Patent No. 4,840,175 to Peyman, which is incorporated herein by reference emit pulsed ultraviolet radiation and can be used to decompose or photoablate tissue in the live cornea so as to reshape the cornea. [0014] Specifically, a laser surgical technique known as laser in situ keratomileusis (LASIK) has been previously developed by the present inventor. In this technique, a portion of the front of a 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 then reattached over the ablated portion of the cornea and assumes a shape conforming to that of the ablated portion.

[0015] However, because only a certain amount of cornea can be ablated without the remaining comea becoming unstable or experiencing outwardbulging (eklasia), this technique is not especially effective in correcting very high myopia or large astigmatic error. That is, a typical live cornea is on average about 500 microns thick. The laser ablation technique requires that at least about 200 microns of the corneal stroma remain after the ablation is completed so that instability and outwardbulging does not occur. Hence, this method typically cannot be effectively used to correct high myopia or large astigmatic error, because, in order to reshape the cornea to the degree necessary to alter its refractive power to sufficiently correct the focusing of the eye, too much of the cornea would need to be ablated.

[0016] Other techniques exist for correcting astigmatic error using markings on a lens. However, these techniques generally only have a mark or multiple marks on a portion of the lens. This type of marking may indicate what direction the lens should be implanted in the cornea; however, they generally do not indicate where on the cornea they should be placed. For example, astigmatic correction is a relatively precise procedure and the lens must be placed both centrally on the cornea or at least in a predetermined position and oriented radially in the correct position, to negate the asymmetric shape of the cornea. The conventional procedures do not allow the proper alignment of the comea surface and the lens implanted thereon. Therefore, existing procedures are inadequate to correct astigmatic error. Furthermore, many of these procedures have permanent markings on the lens, which may hinder the sight of the patient.

[0017] Many intracorneal inlays of this type can also move relative to the central axis of the eye or rotate around the axis of the eye over time and after a flap has been repositioned over the inlay and allowed to heal. If the inlay moves in such a manner, the corrected vision of the eye can be compromised and the vision of the patient may be worse than prior to the surgical technique in some cases.

[0018] Therefore, it is apparent that a need therefore exists for improved methods for further modifying the comea to better correct ametropic conditions.

Summary of the Invention

[0019] Accordingly, it is an object of the present invention to provide a method for adjusting the shape of a live comea to correct high ametropic conditions.

[0020] Another object of the invention is to provide a method for modifying the shape of a live comea to correct astigmatic, hyperopic or myopic conditions. [0021] Yet another object of the present invention is to provide a method for adjusting the shape of a live comea to and maintaining the comea in the proper position relative to the central axis of the eye.

[0022] Still another object of the present invention is to provide an intracorneal inlay for correcting the refractive error in the eye having positioning protrusions thereon. [0023] Still yet another object of the present invention is to provide an intracorneal inlay having at least one protrusion thereon that can be inserted into one or more openings in the comea to maintain the proper position of the inlay relative to the central axis of the eye to thus correct the refractive error in the eye. [0024] Further still it is another object of the present invention to provide an inlay for correcting the refractive error in the eye that has markings thereon to provide proper positioning under a flap in the comea.

[0025] The foregoing objects are basically attained by an inlay, adapted to be positioned on a comea of an eye for correcting refractive error in the eye. The inlay includes a first surface for placement on an exposed surface of the comea, a second surface, opposite the first surface, adapted to be exposed to light, and at least one protmsion extending from at least one of the first and second surfaces and adapted to be inserted into at least one aperture in the comea. The protmsion has a width that is substantially smaller than a radii of the inlay.

[0026] The foregoing objects are also attained by a method of correcting the refractive error in the co ea of an eye, including separating the comea into first and second comeal surfaces, the first comeal surface facing in an posterior direction of the eye and the second comeal surface facing in an anterior direction of the eye. At least one opening is formed in at least one of the first or second comeal surfaces and an inlay is positioned adjacent at least one of the first and second comeal surfaces. The inlay has at least one protmsion extending therefrom, and the at least one protmsion is inserted into the at least one opening.

[0027] 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

[0028] Referring to the drawings which form a part of this disclosure:

[0029] Fig. 1 is an elevational front view of an eye with the comea marked along the main optical axis;

[0030] Fig. 2 is a plan top view of a marking device having five axes, according to an embodiment of the present invention;

[0031] Fig. 3 is a side view in section of the marking device taken along lines 3-3 in Fig. 2.

[0032] Fig. 4 is an elevational front view of the marking device of Fig. 2 overlying the eye of Fig. 1;

[0033] Fig. 5 is an elevational front view of the eye of Fig. 4 after markings were applied thereto by the marking device of Fig. 3 according to an embodiment of the present invention;

[0034] Fig. 6 is an elevational front view of the eye of Fig. 5 with a flap formed in the surface of the comea;

[0035] Fig. 7 is an elevational front view of the eye of Fig. 6 with a device marking the main optical axis under the flap;

[0036] Fig. 8 is an elevational front view of the eye of Fig. 7 with the flap pivoted to expose a surface of the comea and the marking device of Fig. 3 adjacent thereto;

[0037] Fig. 9 is an elevational front view of the eye of Fig. 8 after markings are applied thereto by the marking device of Fig. 3;

[0038] Fig. 10 is plan top view of an inlay according to an embodiment of the present invention with a pliable material overlying the inlay;

[0039] Fig. 11 is a side view in cross section taken along lines 11-11 of the inlay ofFig. 10;

[0040] Fig. 12 is a plan top view of a tool for holding the inlay adjacent a comeal surface and positioning it thereon;

[0041] Fig. 13 is a side view in cross-section of the tool of Fig. 12 taken along lines 13-13; [0042] Fig. 14 is an elevational front view of the eye of Fig. 9 with the inlay of

Fig. 10 positioned on an exposed surface of the comea using the tool of Fig. 13;

[0043] Fig. 15 is a side view in cross-section of the eye of Fig. 14 taken along lines 14-14;

[0044] Fig. 16 is an elevational front view of the eye of Fig. 15 with the flap repositioned, the inlay aligned and a pair of forceps removing the pliable material from the surface of the inlay;

[0045] Fig. 17 is a side view in cross section of Fig. 16, taken along lines 17-17;

[0046] Fig. 18 is a side view in section of the eye if Fig. 17 after the pliable material has been removed;

[0047] Fig. 19 is a plan top view of a ring shaped inlay suitable for the present procedure;

[0048] Fig. 20 is a side cross sectional view of the inlay of Fig. 19 taken along lines 20-20;

[0049] Fig. 21 is a plan top view of a two-piece ring shaped inlay suitable for the present procedure;

[0050] Fig. 22 is a side cross sectional view of the inlay of Fig. 21 taken along lines 22-22;

[0051] Fig. 23 is a side view in section of an eye, wherein a set of pins is forming openings in the comea;

[0052] Fig. 24 is a side view in section of the eye of Fig. 23 with a flap formed in the surface of the comea;

[0053] Fig. 25 is a bottom plan view of a second embodiment of an inlay according to the present invention, wherein the inlay is concave and has protmsion thereon for proper positioning of the inlay and affixing it to a comeal surface;

[0054] Fig. 26 is a side view in section of the inlay of Fig. 25 taken along lines

26-26;

[0055] Fig. 27 is a side view in section of another configuration of the inlay, wherein the inlay is convex;

[0056] Fig. 28 is a side view in section of another configuration of the inlay, wherein the inlay is toric; [0057] Fig. 29 is a side view in section of the inlay of Fig. 25 positioned on a comeal surface of the eye shown in Fig. 24;

[0058] Fig. 30 is a side view in section of the eye and inlay of Fig. 29, with the comeal flap repositioned over the inlay;

[0059] Fig. 31 is a top planar view of an inlay configured according to another embodiment of the present invention;

[0060] Fig. 32 is a side view in section of the inlay of Fig. 31 taken along lines

32-32;

[0061] Fig. 33 is a side view in section of the inlay of Fig. 31 positioned on the eye shown in Fig. 24;

[0062] Fig. 34 is a side view in section of the eye and inlay of Fig. 33 with the flap repositioned over the inlay;

[0063] Fig. 35 is a side view in section of the eye of Fig. 23 with a flap formed in the surface of the comea, wherein the flap is thicker at the periphery than at the center;

[0064] Fig. 36 is a top plan view of another inlay configuration; wherein the inlay has protmsions that extend radially outwardly from the periphery of the inlay;

[0065] Fig. 37 is a side view in section of the inlay of Fig. 36 taken along lines

36-36;

[0066] Fig. 38 is a side view in section of the inlay of Fig. 36 positioned on a co eal surface of the eye shown in Fig. 35; and

[0067] Fig. 39 is a side view in section of the eye and inlay of Fig. 38, with the comeal flap repositioned over the inlay.

Detailed Description of the Invention

[0068] As shown in Figs. 1-17, the refractive properties of the eye can be modified or altered by placing markings 26 and 28 on both the external or outer surface 14 of the comea 12 of an eye 10 and an internal surface 16, respectively. Surface 16 is generally exposed when a flap 18 is formed in the surface of the comea. An inlay or implant 20 having a removable, pliable sheet 22 with markings 24 thereon is positioned on the exposed surface of the comea, and the markings on the inlay are aligned with the markings 26 and 28. Preferably, this procedure is used for astigmatic correction, but may be used with any type of correction to the vision of the eye.

[0069] To begin, the refractive error in the eye is measured using wavefront technology, as is known to one of ordinary skill in the art. The refractive error measurements are used to determine the appropriate shape of lens or inlay 20 to best correct the error in the patient's comea. Preferably, the inlay 20 is manufactured or shaped prior to the use of the wavefront technology and is stored in a sterilized manner until that specific inlay shape or size is needed. However, the information received during the measurements from the wavefront technology can be used to form the inlay using a cryolathe, or any other desired system or machine.

[0070] As seen in Fig. 1, the main optical axis or visual axis 30 of the eye is marked with a dot 32 or any other type of marking, such as cross-hairs or an X. The exact position of visual axis 30 of the eye 10 is determined by asking the patient to focus on a small beam of light, as is known in the art, and the location on the comeal surface is marked, using a marker (such as ink). Preferably, the ink is any conventional ink that is water-soluble and will be washed away after several blinks of the eye or application of water or any other suitable liquid, thus allowing unhindered sight by the patient. [0071] A marking device 34, as seen in Figs. 2 and 3, can then be positioned adjacent the surface 12 of the comea (Fig. 4). Device 34 is preferably formed of metal or plastic and has a handle 36 and a substantially circular head 38. Head 38 is formed of a substantially tubular or cylindrical portion 40 that extends from the handle 36 in a substantially circular manner, leaving an opening or area 42 within the tubular portion. In this example, ten spokes 44 extend radially from a central portion 46 to the tubular portion 40 at equal intervals. In other words, the angle between each spoke 44 and the adjacent spoke is substantially equal to the angle between each other adjacent spoke. Spokes 44 define five separate axes or lines that extend from one portion of the tubular portion 40 to a side opposite or about 180 degrees therefrom. Each spoke is preferably substantially circular and in substantially the same plane as each other spoke. The spokes 44, however, do not necessarily need to be circular and spaced equally apart from one another and can number any number desired. For example, they can number from one to as many can be fit into the desired area 42. [0072] Once the marking device 34 is positioned adjacent the external surface, the device 34 is centered using mark or dot 32. Water based or removable ink (substantially similar to the ink used to mark the visual axis) is then used to mark the surface 14 of the comea 12 along the spokes 44. As seen in Fig. 5, this leaves ten lines 26 extending radially from dot 32 or five axes extending in separate directions. The lines 26 are in substantially the same configuration as the marking device spokes 44. [0073] Preferably, flap or portion 18 can be formed in the surface 14 of the comea 12, as seen in Fig. 6. The flap is formed in the stromal layer of the comea, but does not necessarily need to be formed in the stromal layer and can be formed in any desired portion of the comea. By forming the flap in the stromal layer, the cells of the comea do not cause a gray to white response in the comea, or protein detanurization The flap may be formed be any means desired, such as with a knife, microkeratome, or with a laser, such as a femtosecond laser or any other suitable laser.

[0074] Preferably, an internal area of the comea is separated into first and second substantially circular shaped internal surfaces 16 and 50, respectively, as seen in Fig. 8, to form the circular shaped comeal flap 18. First internal surface 16 faces in an anterior direction of comea 12 and the second internal surface 50 faces in posterior direction of the comea 12. The flap 18 preferably has a uniform thickness of about 10-250 microns, and more preferably about 80-100 microns, but can be any suitable thickness. A portion 52 of flap 18 preferably remains attached to the comea by an area at the periphery of the flap. However, the flap can be any suitable configuration, such as a flap attached to the comea at a location other than at the periphery or a flap that is not attached to the comea at all. Additionally, the flap may be shaped or sized as desired, and does not need to be circular.

[0075] As seen in Fig. 7, a tool or device or spatula needle 54 is inserted under the flap 18, in-between surfaces 16 and 50 and marks the main optical or visual axis 30. The mark 56 is preferably made on the first surface 16 and is lined up or positioned directly under or in about the same position as mark 32 on the extemal surface of the comea.

[0076] The flap is moved or pivoted about portion 52 using any device known in the art, such as a spatula or microforceps or any other device, to expose the first and second comeal surfaces 16 and 50, respectively. The flap preferably exposes a portion of the comeal surface that intersects the main optical axis 30 and allows uninhibited access thereto.

[0077] Device 34 is positioned adjacent the exposed surface 16 and radial lines or axes 28 are made thereon using the removable ink, described above. Lines 28 are made in substantially the same positioning and placement as lines 26. In other words, lines 28 underlie lines 26, so that if flap 18 were replaced, lines 26 would overlie lines 28 and each overlying line would indicate substantially the same radian or axes. Lines 28 are formed in substantially the same manner as lines 26 and the description thereof applies to lines 28.

[0078] As seen in Figs. 10 and 11, inlay or lens 20 is preferably a substantially circular intracorneal inlay. Additionally, inlay 20 is preferably any polymer or hydrogel having about 70% to about 95% water content, and more preferably of about 78% to about 80% water content; however, the water content can be any percentage desired. The inlay may be formed from synthetic or organic material or a combination thereof. For example, the inlay can be collagen combined with or without cells; a mixture of synthetic material and comeal stromal cells; silicone or silicone mixed with collagen; methylmetacrylate; any transparent material, such as polyprolidine, polyvinylpylidine, polyethylenoxyde, etc.; or any deformable polymer, which can change its shape with radiation after implantation.

[0079] Furthermore, inlay 20 has a first side or surface 58 and a second side or surface 60, and is preferably shaped with an asymmetrical cross-section, as seen specifically in Fig. 11, so that it can correct astigmatic error in the eye. Preferably, as stated above, inlay 20 may come in many configurations and not necessarily that shown in Fig. 11, to correct many different degrees and variations of astigmatic error. Furthermore, inlay 20 may be used to correct hyperopia, myopia or any other vision problems or a combination of these vision problems and astigmatism. [0080] Second surface 60 preferably is curved and pliable, so that it is able to conform to the first surface 16 of the comea 12. The implant is preferably substantially circular, having a diameter of between about 2-10 mm and can have a refractive index different than that of the comea or the same as that of the comea. Preferably, the inlay has a refractive index of about 1.2 to 1.4, and more preferably of about 1.33. If the refractive index is the same as the comea, the total refractive index of the comea is altered after implantation of the inlay and repositioning of the flap. However, the inlay can be any size and/or configuration desired.

[0081] Furthermore, as seen in Fig. 11 , a pliable or bendable sheet or film of transparent material 62 is positioned to overlie and conform to surface 58. Sheet 62 is preferably a synthetic material, such as any suitable polymer, and is substantially circular with markings or lines 24 thereon. Markings 24 have substantially the same positioning and placement as lines 26 and 28, or are 10 lines that radially extend from a center to form five separate axes. The description of lines 26 and 28 applies to markings 24. In other words, lines 24 are configured in such a manner that if the center of the markings 24 was placed on the marking 32 the lines can be adjusted or orientated so that markings 24 would overlie lines 28 and/or 26, each line indicating substantially the same radian or axis. Furthermore the center 66 of the markings 24 is preferably in the center of the inlay or positioned in any predetermined portion of the inlay.

[0082] This configuration of the lines and markings 28 and 24 allows the inlay to be placed on the exposed surface of the comea directly over the visual axis 30 and oriented so that lines and markings 28 and 24 are precisely or substantially matched, as seen in Fig. 14. Furthermore, by placing the markings on the inlay and the comea as described, an asymmetric astigmatic inlay can be correctly and accurately placed on the exposed surface of the comea. It is generally crucial to the sight of the patient's eye, especially during astigmatic correction, to have the inlay precisely oriented to correct the existing error. If the inlay is not both centered over the visual axis, or at least positioned in a predetermined position over the visual axis, and oriented properly with respect to radial position, the inlay will not correct the desired astigmatic error and may even increase the refractive error in the comea. Therefore, it can be seen that this inlay can be accurately positioned both radially and centrally on the eye to improve the vision of the eye.

[0083] Preferably, inlay 20 is positioned adjacent the surface of the comea, using tool or holding device 80, in-between first and second comeal surfaces 16 and 50. As seen in Figs. 12 and 13, tool 80 is preferably a plastic tool having a handle 82 and a substantially circular head 84; however, tool 80 can be any material and shape desired that would allow the placement of inlay 20 on a comeal surface. Head 84 has an open center portion 86 defined by an L-shaped holding portion 88, which is curved in a similar configuration as the surface of the comea to facilitate positioning of the inlay; however, portion 88 can be straight or any other configuration desired. Portion 88 has a bottom wall 90 and a sidewall 92 that are sized and configured to hold inlay 20 therein (Figs. 14 and 15). Additionally, wall 90 has markings or lines 91 that are substantially similar and oriented to the lines or markings 24 on the inlay. These markings allow the inlay to be aligned with the tool 80 when positioning the inlay adjacent the comea. Furthermore, the walls 86 and 88 have an opening 94 at one end, preferably opposite or 180-degrees away from the handle 92. The opening allows the resilient head to separate and the inlay to be properly positioned in the exact or precise location desired on the exposed comeal surface, after it is aligned with the markings of the comeal surface, as described above. [0084] It is noted that the inlay can be positioned without the use of tool 80, in any convention manner desired or any other manner, and does not necessarily need to be positioned on an internal surface of the comea but may be placed or positioned on the external surface of the comea.

[0085] Once tool 80 is removed and the inlay properly positioned, the flap 18 is replaced so that it covers or lies over the sheet 62 in a relaxed state, as seen in Figs. 16 and 17. In other words, inlay 20 or sheet 62 does not force flap 18 away from the internal surface 58 and therefore the refractive properties of the comea are not altered due to a tension force being applied to the flap. Preferably, the flap 18, the inlay 20, the visual axis 30 and surface 16 are all precisely lined up using the above described markings and lines. If any markings are off, the inlay and/or the flap can be repositioned by using small forceps. The forceps can be extended underneath the flap 18 to move the inlay with respect to the visual axis either in a rotational or a linear manner. [0086] As seen in Figs. 16 and 17, forceps 68 are used in grasp the sheet 62 and remove the sheet from the surface of the inlay, thus removing any markings on the inlay 20 that may hinder sight. Additionally, the markings on the eye would wash away after a short period of time due to the liquids developed naturally by the eye; however, if desired the ink my be washed of manually with the application of water or any other suitable liquid. Furthermore, it is noted that the sheet does not necessarily need to be removed and can remain on the inlay even after the procedure is completed. The ink on sheet 62 may be removable in the same manner as the ink to mark the comea and would thus wash off after a short time period.

[0087] Additionally, the markings may be placed directly on the inlay and do not necessarily need to be on a sheet. This type of marking would allow the same proper placement without the need to remove the sheet. As stated above, the ink forming the markings could be removable.

[0088] It is noted that the markings do not necessarily need to be in the configuration described and can be any type of markings desired. For example, the markings can be radial dots that are positioned along the desired axes or radians or they can be concentric circles or a single circle or any other polygon desired or configuration of marks or dots desired that would allow the matching of the inlay, flap and surface of the comea in the manner described above. Furthermore, the markings do not need to be removable and can be permanent, whether they are made with ink or actual alterations to the comea and/or inlay, or the markings can be any combination of removable and/or permanent markings.

[0089] As seen in Figs. 19 and 20, the inlay can be a ring-shaped inlay 120 with first and second surfaces 158 and 160. Inlay 120 is formed from substantially similar materials and therefore would have substantially similar properties to those of inlay 20 and therefore, the description thereof applies to the material and properties of inlay 120. As seen in Fig. 19, the inlay can have one portion that is larger than another portion, or in other words an asymmetric configuration that would correct astigmatic error as described above.

[0090] Inlay 120 can be used for correction of myopia or astigmatism or both. As with the above-described inlay, inlay 120 has a sheet of pliable, transparent material 162 overlying surface 158. However, sheet 162 is preferably ring-shaped and covers the ring shaped portion of inlay 120. Furthermore, as with sheet 62, sheet 162 can be used to position and orientate inlay 120 relative to both the comeal flap 18 and the comeal surface 16 and the visual axis 30, as described above. Sheet 162 can also be removed in a similar manner as to that described above for sheet 62. [0091] As seen in Figs. 21 and 22, inlay 220 can be a ring-shaped inlay similar to inlay 120 but with portion portions 220a and 220b. As seen specifically in Fig. 22, portion of the inlay 220a can be larger than portion 220b for correction of astigmatic error, as described above. Furthermore sheet 262 can overlie the inlay in a similar manner as sheet 162. However, sheet 262 has two portions 262a and 262b, which overlie portions 220a and 220b, respectively. Inlay 220 is substantially similar to inlay 120 and inlay 20 and the descriptions thereof apply to inlay 220.

[0092] Additionally, the entire procedure for inlay 20 is applicable to both inlay

120 and inlay 220 and any description thereof is applicable to inlays 120 and 220.

Embodiment of Figs. 23-39

[0093] Figs. 23-34 illustrate a second embodiment of the present invention, where a first needle or pin 310 and a second needle or pin 312 are used to form first and second opening or apertures 314 and 316, respectively, in the comea 12 of the eye 10. The apertures allow an inlay 320 having first and second protmsions 322 and 324, respectively, to be properly positioned and affixed to the comea. [0094] Pins 310 and 312 are preferably 25 or 27 gauge metal needles that have a sharp or pointed end and that can pierce or form openings 314 and 316, respectively in the comea 12. It is noted that pins 310 and 312 can be coupled together to form precisely spaced and positioned openings, they can be separate to allow variance in the spacing and positioning or for forming the openings at separate times, or they can be the same needle. Additionally, pins 310 and 312 can be any size, shape or material desired that would allow the desired openings in the comea to be formed and do not necessarily need to be 25 or 27 gauge needles.

[0095] Each pin is preferably long enough to pierce the comeal epithelium and form the openings 314 and 316 in the comeal stroma and can be stained with a material that would make identification of the position of the openings 314 and 316 easier. For example, the material can be methylen blue or trypan-blue, sodium-fiourscein, indocyanin-green, lissamin green, or any other biocompatible stain or material that would aid in identification of the position of the openings. [0096] As shown in Fig. 24, a flap 318 is formed in the comea, by separating the comea into a first comeal surface 326 and a second comeal surface 328. The first comeal surface generally faces in a posterior direction relative to the eye and the second comeal surface generally faces in an anterior direction relative to the eye. The flap may be formed be any means desired, such as with a knife, microkeratome, or with a laser, such as a femtosecond laser or any other suitable laser. The flap is generally a substantially circular flap that is attached to the comea by a hinged portion 330 that is at the periphery of the flap. Flap 318 is substantially similar to flap 18, described above, and the discussion of flap 18 is applicable to flap 318. However, it is noted that the flap 18 can be any shaped or form desired. For example, the flap can be attached at a position other than the periphery, such as at the central portion of the flap or an area surrounding the main optical axis 319, or the flap can be completely separated from the rest of the comea. Furthermore, it is not necessary to form a flap and the comea can be separated into first and second surfaces to form a pocket with an incision in the surface of the comea to allow access thereto.

[0097] When flap 318 is formed, it preferably separates the comea through openings 314 and 316. This forms a first through passageway 314a and a second through passageway 316a through the comeal flap, and openings 314b and 316b in the stromal layer of the comea.

[0098] As seen in Figs. 25 and 26, inlay 320 is preferably substantially circular and has first surface 332 and a second surface 334. Inlay 320 has radii extending from the center of the inlay to the periphery. Surface 332 is generally adapted to be positioned facing in an anterior direction of the eye and adjacent surface 326 of the comea, and surface 334 is generally adapted to be positioned facing in a posterior direction of the eye and adjacent surface 330 of the eye. Extending from the second surface 334 are preferably first and second protmsions or pegs 322 and 324, respectively. Each protmsion is substantially cylindrical and extends generally transverse to the second surface 334. Preferably, the protmsions are very small and do not effect the vision of the patient. For example, the width or diameter of each protmsion is preferably substantially smaller than the radius of the inlay, (if the inlay is circular), and each radii, if the inlay is any shape, including circular. In other words, regardless of the shape of the inlay, the distance from the approximate center to the edge or periphery of the inlay is greater than the width or diameter of each protmsion. Even more preferably, the width of the protmsions is about the same as a 25 or 27 gauge needle and is therefore, significantly less than that of the inlay. The first and second protmsions are preferably diametrically opposed and positioned at the periphery of the inlay 320. However, the protmsions do not necessarily need to be positioned in this manner and the protrusions can be any number desired. For example, there can be as few as one protmsion and as many as desired and each protmsion can be positioned anywhere on the second surface 334 and does not need to be positioned relative to any other protmsion. [0099] Inlay 320 is preferably any polymer or hydrogel having about 70%) to about 95%o water content, and more preferably of about 78% to about 80%> water content; however, the water content can be any percentage desired. The inlay may be formed from synthetic or organic material or a combination thereof. For example, the inlay can be collagen combined with or without cells; a mixture of synthetic material and comeal stromal cells; silicone or silicone mixed with collagen; methylmetacrylate; any transparent material, such as polyprolidine, polyvinylpylidine, polyethylenoxyde, etc.; or any deformable polymer, which can change its shape with radiation after implantation. Inlay 320 preferably has the same refractive index as the comea, but can have a different refractive index or have portions that have the same refractive index and portions that have a different refractive index than the comea.

[OOIOO] Inlay 320, as shown in Fig. 25 and 26 has a concave shape but this inlay is shown for merely exemplary purposes. The inlay can be a concave inlay 320a (Fig. 27) or a toric inlay 320b (Fig. 28) or any other shape desired. [OOIOI] Furthermore, the inlay can be stained with a very weak or diluted biocompatible stain or colorant, such as methylen blue, trypan-blue, sodium-flourscein, indocyanin-green, lissamin green or any other material or stain that aids in the visibility of the orientation of the inlay and the position of the protmsions. Generally, the inlay is soaked in the biocompatible material prior to placement on the comea. By soaking the inlay in such a manner, it is much easier to see the inlay relative to the co ea when positioning the inlay on the surface of the comea. [00102] Once flap 318 has been formed, it is moved using a spatula or other acceptable device about hinge portion 328, exposing second comeal surface 330. Preferably openings 314b and 316b are located (with the help of one of the above- identified stains) and second surface 334 of inlay 320 is positioned adjacent surface 330 with protmsions or pegs 322 and 324 being inserted into openings 314b and 316b, respectively. If the inlay is asymmetric or toric in any fashion, protmsions 322 and 324 can be used to properly position the inlay with respect to the main optical axis of the eye. It is often difficult to determine which direction or orientation the inlay must be placed to properly correct an astigmatism and therefore, if the inlay is turned about its center of axis or moved laterally with respect to the main optical axis of the eye, the astigmatic error in the eye can be exacerbated, rather than corrected. Thus, it is important that the inlay be correctly orientated when positioned in the eye.

[00103] Furthermore, inlay 320 will resist both lateral and rotational movement after placement. Since the protmsions are held in the openings, the inlay 320 will not display any tendencies to move either during implantation or later after implantation. Many conventional intracorneal inlays tend to move relative to the comea well after the implantation has occurred, requiring repositioning of the inlay, and thus an additional unnecessary surgical procedure.

[00104] Additionally, as shown in Fig. 29, an adhesive 329, such as a cologen gel or fibren sealant (i.e., thrombine), can be applied to the inlay 320 to help hold the inlay in position. More specifically, the adhesive can be applied to the periphery of the lens, the protmsions or any other suitable portion. Preferably only a small amount or a drop of biological glue is added to the periphery of the inlay. Adhesive 329 can also be a liquid thermobond, such as cyanociylate, hydrogel or cynoaerulate. Furthermore, adhesive 329 can be a synthetic material, such as FocalSeal-L, which is a synthetic absorbable sealant and primer solution. However, the adhesive may be any biogradable or nonbiodegradable substance suitable for implantation in the eye. [00105] Adhesive 329 is also suitable for holding the flap 318 to the comea. Preferably, the adhesive is applied to the inlay opposite the hinge 328 of the flap. In otherwords, the adhesive is applied to the edge of the contact in a position that is diametrically opposed to the hinge of the flap. When the adhesive is positioned in this manner, it holds the flap to the comea and the flap is less likely to wrinkle or fold, when repositioned over the inlay, as described above.

[00106] After the inlay is properly positioned, the flap 318 is repositioned over the inlay, as described above in the discussion of flap 18. Preferably the flap is replaced so that it covers or lies over the first surface 332 of the inlay 320 in a relaxed state, as seen in Fig. 30. In other words, inlay 320 does not force flap 318 away from surface 330 and therefore the refractive properties of the comea are not altered due to a tension force being applied to the flap.

[00107] It is not necessary for the flap to have protmsions extending from only the second surface of the inlay. As shown in Figs. 31-34, protmsions 322b and 324b can also extend from the first surface 332a of the inlay 320c, as well as protmsions 322a and 324a, which extend from the second side 334a of inlay 320c. Additionally, protmsions extending form the first side can be the only protmsions on the inlay and it is not necessary to have protmsions extending from both the first and second surfaces. [00108] As stated above, protmsions 322a and 324a are inserted into openings 314b and 316b in the stroma. Furthermore, protmsions 322b and 324b are inserted into through passageways 314a and 316a, respectively, when flap 318 is repositioned over the inlay, as described above for inlay 320. The redundancy of the protmsions on the first and the second surfaces allows for a less likelihood that the inlay will move relative to the comea, both laterally and rotationaly, during and subsequent to the procedure. [00109] Other than the above-described differences, inlay 320c is substantially similar to inlays 320, 320a and 320b discussed above and any description thereof is applicable to inlay 320c.

[00110] To reduce or eliminate additional refractive error, a laser (not shown), preferably an excimer laser, can then be aimed and fired at the external surface of the inlay 320, ablating a portion thereof. Preferably, about 1-100 micron thickness is ablated, but any thickness that achieves the desired result can be ablated from the inlay. The excimer laser prior to repositioning of the flap or the flap can be reopened initially using, in the manner described above.

[00111] As shown in Fig. 31 , when a mechanical keratome is used, the curvature of the stromal or second surface 330a is steeper than the curvature of the external surface of the comea. In other words, the thickness in the center 340 of the flap 318a is less than the thickness at the periphery 342 of the flap.

[00112] In this case it may be necessary for inlay 320d to have a slightly steeper second surface 334 and a slightly thinner periphery 344 than the inlays described above. [00113] Additionally, protmsions or 322d and 324d on inlay 320d preferably are diametrically opposed relative to each other, and each pin has a first portion 346 and 348, respectively that extend radially outwardly from the periphery 344 of inlay 320d. A second portion 350 and 352 of the first and second protmsions, respectively, then turns about 90° and extends in the direction that second surface 334d faces in the opposite or transverse direction that first surface 332d faces. By forming the protmsions in this manner more area of the inlay can be used for vision correction and the protmsions will not cause any variance in the refractive property of the inlay.

[00114] The second portions 350 and 352 of the respective protmsions 322d and 324d are inserted into the openings 314b and 316b, as described above for inlay 320. Other than the above-described differences, inlay 320d is substantially similar to inlays 320, 320a, 320b and 320c, discussed above, and any description thereof is applicable to inlay 320d.]

[00115] While various advantageous 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.

Claims

WHAT IS CLAIMED IS:

1. An inlay for positioning on a comea of an eye for correcting refractive error in the eye, comprising: a first surface for placement on an exposed surface of the co ea; a second surface, opposite said first surface, adapted to be exposed to light; and at least one protmsion extending from at least one of said first and second surfaces and adapted to be inserted into at least one aperture in the comea, said protmsion having a width that is substantially smaller than a radii of said inlay.

2. An inlay according to claim 1, wherein said at least one protmsion extends from the periphery of at least one of said first and second surfaces.

3. An inlay according to claim 1, wherein said at least one protmsion includes at least two protmsions; and said at least one aperture in the comea includes at least two apertures, each of said at least two protmsions adapted to be inserted into a respective aperture.

4. An inlay according to claim 3, wherein said at least two protrusions extend from said first side and are adapted to be inserted into the comeal stroma.

5. An inlay according to claim 3, wherein said inlay is adapted to be positioned between first and second comeal surfaces, said first comeal surface facing in an posterior direction of the eye and said second comeal surface facing in an anterior direction of the eye.

6. An inlay according to claim 5, wherein said at least two apertures are formed in the second comeal surface.

7. An inlay according to claim 5, wherein said at least two apertures include a first aperture and second aperture, said first aperture is formed in said first comeal surface and said second aperture is formed in the second comeal surface.

8. An inlay according to claim 5, wherein said at least two apertures are formed in the first comeal surface.

9. An inlay according to claim 3, wherein said at least two protmsions extend from a periphery of said first surface and are diametrically opposed.

10. An inlay according to claim 3, wherein said at least two protmsions extend from a periphery of said second surface and are diametrically opposed.

11. An inlay according to claim 1, wherein said inlay is adapted to be positioned between first and second comeal surfaces, said first surface facing in an posterior direction of the eye and said second surface facing in an anterior direction of the eye.

12. An inlay according to claim 11, wherein said first and second comeal surfaces form a flap, said inlay adapted to be positioned under said flap.

13. An inlay according to claim 1, wherein said inlay is generally concave.

14. An inlay according to claim 1, wherein said inlay is generally convex.

15. An inlay according to claim 1, wherein said inlay is generally toric.

16. An inlay according to claim 1, wherein said at least one protmsion includes a first protmsion and a second protmsion, said first and second protrusions extending from substantially opposite sides of said first surface and are adapted to facilitate orientation of the inlay relative to the comea.

17 . an inlay according to claim 1, wherein at least a portion of said inlay is stained with a biocompatible material.

18. An inlay according to claim 1, further including a removable sheet overlying said second surface, said sheet having markings to facilitate the positioning of the inlay on the comea.

19. An inlay according to claim 1, wherein an adhesive is applied to said inlay.

20. A method of correcting the refractive error in the comea of an eye, comprising the steps of forming at least one opening in at least one of the first or second comeal surfaces, separating the comea into first and second comeal surfaces, said first comeal surface facing in an posterior direction of the eye and said second comeal surface facing in an anterior direction of the eye, positioning an inlay adjacent at least one of said first and second comeal surfaces, said inlay having at least one protmsion extending therefrom, and inserting said at least one protmsion into said at least one opening.

21. A method according to claim 20, wherein said separating step includes, separating the comea into first and second comeal surfaces to form a flap.

22. A method according to claim 21, wherein said at least one opening includes at least two openings formed in the second comeal surface; said at least one protmsion includes at least two protmsions; and said positioning step includes, positioning the inlay adjacent said second surface, and said inserting step includes inserting the at least two protmsions into a respective opening of said at least two openings.

23. A method according to claim 20, wherein said separating step includes separating the first and second comeal surfaces to form a flap.

24. A method according to claim 23, wherein said separating step includes forming a flap that has a periphery portion that is thicker than a center portion.

25. A method according to claim 23, wherein said positioning step includes, positioning an inlay having a center portion that is thicker than a peripheral portion.

26. A method according to claim 20, wherein said at least one protmsion extends from the periphery of at least one of said first and second surfaces.

27. A method according to claim 20, further including the step of marking each of said at least two openings with a biocompatible material.

28. A method according to claim 20, further including the step of applying an adhesive to said inlay.

29. A intracorneal inlay for the correction of refractive error in the comea of an eye, comprising: a first surface adapted to be positioned on an exposed surface of the comea and having a perimeter; a second surface opposite the first surface; a first protrusion extending from said first surface at said perimeter and adapted to be inserted into a first opening in the exposed surface of the comea; and a second protmsion extending from said first surface at said perimeter, generally spaced apart from said first protmsion, said second protmsion adapted to be inserted into a second opening in the exposed surface of the comea.

30. An inlay according to claim 29, wherein said intracorneal inlay is adapted to be positioned between first and second comeal surfaces, said first surface facing in an posterior direction of the eye and said second surface facing in an anterior direction of the eye.

31. An inlay according to claim 30, wherein said first and second comeal surfaces form a flap, said intracorneal inlay adapted to be positioned under said flap.

32. An inlay according to claim 29, wherein said intracorneal inlay is generally concave.

33. An inlay according to claim 29, wherein said intracorneal inlay is generally convex.

34. An inlay according to claim 29, wherein said intracorneal inlay is generally toric.

35. An inlay according to claim 29, wherein said first and second protmsions are adapted to facilitate orientation of the inlay relative to the comea.

36. An inlay according to claim 29, further including a removable sheet overlying said second surface, said sheet having markings to facilitate the positioning of the inlay on the comea.

37. An inlay according to claim 29, further including said first and second protmsions are diametrically opposed.

38. An inlay according to claim 29, further including an adhesive that is applied to a periphery of said intracorneal inlay.