Implantable lenses with modified edge regions

IS 2 550 488 T3

DESCRIPTION

Implantable lenses with modified edge regions

Field of the invention

The field of the invention relates generally to implantable lenses, and more particularly to implantable lenses having modified edge regions.

Background information

As is well known, abnormalities in the human eye can lead to vision defects. Some typical abnormalities include variations in the shape of the eye, which can lead to myopia (seeing badly from a distance), hyperopia (seeing badly from close up) and astigmatism, as well as variations in the tissue present in the eye, such as a reduction in the elasticity of the lens that can lead to presbyopia. Certain devices, generally called implantable lenses, have been used to successfully treat these and other types of vision defects.

Implantable lenses typically fall into one of two categories: intraocular lenses (IOLs) that can be implanted deep within the eye to replace the natural lens of the eye, and corneal implants, which are typically implanted near the surface of the eye in the area. cornea to alter incident light. Corneal implants, in turn, can be classified as superimposed corneal implants or embedded corneal implants. An overlay corneal implant is an implant that is placed on the cornea so that the outer layer of the cornea, eg, the epithelium, can grow over and encompass the implant. An embedded corneal implant is an implant that is surgically implanted into the cornea beneath a portion of the corneal tissue using, for example, keratophakia. Exemplary methods of implanting an embedded corneal implant are described in greater detail in US 2005/017 8394 A1 filed August 23, 2004, and entitled Method for Keratophakia Surgery.

Because corneal implants are placed within corneal tissue, a significant concern is preventing the tissue from adversely reacting to the implant and creating undesirable conditions. For example, certain adverse tissue reactions, such as cellular secretions and keratocytic accumulation, can lead to an undesirable condition called corneal clouding. Corneal turbidity can obstruct the passage of light through the cornea and the implant and thus prevent proper treatment of the visual defect. Although corneal turbidity is multifactorial, there is evidence that it may be influenced, at least in part, by the mechanical forces imposed on the keratocytes in the corneal tissue.

Additionally, some corneal implants that are relatively flat around their outer edges, such as shallow spherical implants and aspherical implants, to name a few, may experience edge elevation. Edge lift occurs when the anterior surface of the implant around the outer edge tends to curve or lift back from the apex. Figure 1 is a cross-sectional view of a conventional corneal implant 20 experiencing edge elevation, which is exaggerated for purposes of illustration. In this case, implant 20 has an outer edge 21, an anterior surface 22, an apex 23, and a posterior surface 24. An ideal edge profile is indicated by the dashed line 10. In the ideal case, the most posterior point in anterior surface 22 is located on outer edge 21. However, in a lens experiencing edge lift the most posterior point of anterior surface 22 may be located at a position 24 closer to apex 23 than outer edge 21. Edge lift may progress and accumulate over time afterward. of its generation and results in impaired optical performance and can also make the implant procedure more difficult.

Accordingly, there is a need for improved implantable lenses that reduce adverse physiological reactions to the presence of the lens and decrease the risk of edge elevation.

Document US 6 875 232 B2 discloses a corneal implant formed of a microporous, permeable and biocompatible hydrogel, with a refractive index in the range of 1.36-1.39, to be substantially similar to the refractive index of the cornea. . The implant is generally circular in shape and larger than the size of the pupil in bright or normal light conditions, and can be used specifically to correct presbyopia. For simple or compound presbyopia, the implant is prepared by modifying the radius of curvature in the central 1.5-3 mm, thus forming a multi-focal external corneal surface where the central portion of the cornea achieves extra added power to work closely. .

US 5 123 921 A discloses a lens for implantation in the cornea of ​​the eye to provide correction of myopia. The lens is a one-piece member having an anterior surface, a posterior surface, and a peripheral transition zone that serves to join the anterior and posterior surfaces. The overall configuration of the lens is circular, as viewed from the central axis of the lens. The anterior surface of the lens is convex and the posterior surface is concave. The anterior and posterior surfaces are joined at the periphery of the lens by a peripheral transition zone. The peripheral transition zone is formed of a first annular surface, a second

ES 2 550 488 T3 annular surface and a third annular surface. The first annular surface is in a plane perpendicular to the central axis of the lens and abuts the posterior surface. The second annular surface is also generated around a point along the central axis, is perpendicular to and abuts the first annular surface, and is in a plane parallel to the central axis line. The third annular surface is an annular spherical segment and abuts both the second annular surface and the anterior surface.

Summary

In accordance with the present invention there is provided an embedded corneal implant of claim 1.

Additional aspects of the embedded corneal implant are set forth in the dependent claims.

As disclosed hereinafter, implantable lenses having a body with a first region and a second region, where the first region has a first refractive index and a second region that has a second refractive index different from the first index. refraction. The first region may be permeable to a sufficient amount of fluid and nutrient to substantially support the tissue adjacent to the body. The second region may have the same permeability as the first region or it may be relatively less permeable than the first region. The first and second regions can provide refractive correction over any desired distance (ie, near / far, far / near, etc.) and can be arranged in any desired manner. The lens may have an anterior surface with any desired curvature and may be configured as an embedded corneal implant or an overlay corneal implant in another example, the first region may be composed of a first polymeric material and the second region may be composed of a second polymeric material, where the first and second regions are integrally coupled to each other. Any number of regions, two or more, can be included as desired, with one or more regions integrally coupled to each other.

As disclosed, there is an exemplary implantable lens manufacturing method, where the method includes forming a first core comprising a first polymer having a first refractive index, forming an interface region around at least a portion of the first core, forming a second core comprising a second polymer around at least a portion of the interface region, the second polymer having a second refractive index different than the first refractive index and forming an implantable lens from the first and second cores. The interface region can include a mixture of the first and second polymers and can have a third refractive index different from the first and second refractive indices and can be used to provide additional refractive correction or serve as a gradual transition between the first and second polymeric regions. . The interface region can integrally couple the first and second nuclei to each other and can include an interpenetration network of the first polymer and the second polymer.

The exemplary method may also include placing a monomer solution in contact with the first core, where the first polymer is soluble in the monomer solution, dissolving a portion of the first core in the monomer solution so that the monomer solution and the dissolved portion of the first core mix in the interface region, and polymerize the mixture of the monomer solution and the dissolved portion of the first core in the interface region.

Also previously disclosed herein is an implantable lens having a body that includes a first substantially aspherical surface having a first asphericity (Q) and a second substantially aspherical surface having a second asphericity (Q) different from the first asphericity. The first and second aspherical surfaces can be configured to aid in vision at any desired distance or ranges of distances from the eye and can be arranged in any desired manner.

Other systems, methods, features, and advantages of the invention will be or will become apparent to one of ordinary skill in the art upon examination of the following figures and detailed description. All such additional systems, methods, features, and advantages are intended to be included within this disclosure, to be within the scope of the invention, and to be protected by the appended claims. It is also intended that the invention is not limited to the details of the example embodiments.

Brief description of the figures

The details of the invention, including manufacture, structure and operation, can be seen in part by studying the accompanying figures, in which like reference numerals refer to like segments. Of the illustrated lenses, only the lens of Figure 9 is an embodiment in accordance with the present invention.

Figure 1 is a cross-sectional view of a conventional implantable lens.

Figure 2A is a perspective view showing an example of an implantable lens.

Figure 2B is a top-down view depicting another example of the implantable lens.

IS 2 550 488 T3

Figures 2C-E are cross-sectional views taken along line 1-1 of Figure 2B depicting additional examples of the implantable lens.

Figure 3 is a cross-sectional view showing an anterior portion of a human eye with an example of the lens implanted therein.

Figures 4-8 are cross-sectional views taken along line 1-1 of Figure 2B depicting additional examples of the implantable lens.

Figure 9 is a cross-sectional view taken along line 1-1 of Figure 2B depicting an exemplary embodiment of the implantable lens.

Figure 10A is a top-down view depicting another example of the implantable lens.

Figure 10B is a cross-sectional view taken along line 2-2 of Figure 10A depicting another example of the implantable lens.

Figure 11A is a perspective view showing another example of the implantable lens.

Figure 11B is a top-down view depicting another example of the implantable lens.

Figures 11C-D are cross-sectional views taken along line 3-3 of Figure 11B depicting additional examples of the implantable lens.

Figures 12A-D are block diagrams depicting an exemplary manufacturing method of the implantable lens.

Figure 13 is a cross-sectional view showing another example of the implantable lens.

Figure 14A is a top-down view depicting another example of the implantable lens.

Figures 14B-C are cross-sectional views taken along line 4-4 of Figure 14A depicting additional examples of the implantable lens.

Detailed description

This document describes improved implantable lenses with modified edge regions that can reduce the stimulation of adverse tissue reactions in the vicinity of the lens. Figures 2A-E depict various views of an example implantable lens 100. Figure 2A is a perspective view showing an implantable lens 100, where the lens 100 has a lens body 101, an anterior surface 102, a posterior surface 103, and an outer edge surface 104. Figure 2B is a view of up below lens 100 taken in direction 110. In this case, it can be seen that the lens body 101 has a generally circular external profile 119 with the central apex 105 representing the most anterior point of the anterior surface 102. The diameter 12 represents the overall diameter of the lens body 101 and the diameter 114 represents the diameter of correction portion 122, which is the portion of anterior surface 102 configured to provide correction for one or more specific visual defects.

Figure 2C is a cross-sectional view of lens 100 taken along line 1-1 of Figure 2B. From this view it can be seen that anterior surface 102 is substantially spherical, with a radius of curvature 106 measured from vertex 108 located at central axis 118, which intersects vertex 105. Similarly, posterior surface 103 also has its own radius of curvature 107 measured from vertex 109. The correcting power of the lens 100 depends on these radii 106-107 and can be varied as desired by adjusting any of the radii 106-107. It can also be seen in this case that the lens 100 is configured to correct for hyperopia, that is, the ratio of the anterior surface 102 to the posterior surface 103 gives the lens body 101a a shape similar to a meniscus that converges along line 1-1. The thickness of the lens body 101 along the central axis 118 is referred to as the center thickness 140.

Figure 2D is an enlarged cross-sectional view of lens 100, showing region 111 of Figure 2C in greater detail. In Figure 2D, the correction portion 122 of the front surface 102 is substantially spherical and the front surface 102 also includes a beveled portion 124. In this case, the beveled portion 124 is curved, with a single radius of curvature and is called bevel radius 124. As used herein, bevel is defined to include flat surfaces, curved surfaces, and surfaces of any other shape. The radius of the chamfer 124 abuts the spherical portion 122 at interface 123. Adjacent to the radius of the chamfer 124 is the surface of the outer edge 104, the junction between the radius of the chamfer 124 and the surface of the outer edge 104 being called interface 125. The outer edge surface 104 includes a first portion 126 and a second portion 128, which abut each other at the interface 127. The second portion of the edge surface 128 abuts the rear surface 103 at the interface 129. In this case the First, the portion of the surface of the edge 126 is curved and is called the radius of the edge 126. In this lens, the thickness of the edge 130 is defined as the height of the second portion of the surface of the edge 128 in the Z direction from the most posterior point of the lens body 101 (interface 129 in this case) towards the interface 127.

Figure 2E is another cross-sectional view of region 111 depicting the example of Figure 2D with slope angle 132 of edge radius, which defines slope of edge radius 126. Slope angle 132 of edge radius Edge can be defined as the angle between axes 131 and 133. In this case, axis 131 is parallel to central axis 118 and intersects interface 125, while axis 133 intersects interfaces 125 and 127. Also represented in this case is a slope angle 135 of the bevel radius, which defines the slope of the bevel radius 124. The slope angle 135 of the bevel radius can be defined as the angle between axes 134 and 136. In this case , axis 134 is parallel to central axis 118 and intersects interface 123 and axis 136 intersects interfaces 123 and

IS 2 550 488 T3

125.

As can be seen in Figures 2D-E, the edge radius 126 preferably slopes in the Z direction to a greater degree than the chamfer radius 124, so that the edge radius 126 converges toward the back surface 103 at a greater degree. speed than the radius of the bevel 124. Stated in terms of slope angles, the slope angle 132 of the edge radius is preferably smaller than the slope angle 135 of the radius of the bevel. As a result, lens 100 is less susceptible to edge lift. Also, the gradual transition between spherical portion 122 and posterior surface 103 can reduce the stimulation of adverse tissue reactions to lens 100.

For example, Figure 3 is a cross-sectional view depicting an anterior portion of the human eye 200 that includes the lens 202, vitreous 203, ciliary body 204, iris 205, and cornea 206 with an example lens 100 implanted therein. . In this case, the lens 100 is shown implanted as an embedded corneal implant although, it could be seen that the lens 100 may also be implanted as a superimposed corneal implant at a position closer to the anterior surface of the cornea 206. The gradual transition in the edge region of lens 100 facilitates acceptance of lens 100 surrounding corneal tissue 207, more so than conventional lenses with a sharp or stepped transition without beveling between the anterior and posterior surfaces. As a result, lens 100 is less susceptible to undesirable conditions such as corneal haze and the like. In addition, during the implantation procedure, the modified edge region of lens 100 makes it easier to determine if lens 100 is properly oriented or if lens 100 is inverted.

To support the cornea 206 and prevent tissue necrosis, an adequate level of fluid and nutrient transfer must be maintained within the cornea 206. Accordingly, the lens body 101 is preferably composed of a material with sufficient permeability to allow for fluid and nutrient transfer between corneal tissue 207 adjacent anterior surface 102 and posterior surface 103, to support the cornea for a desired period of time. For example, in one example the lens body 101 is composed of a microporous hydrogel material. Microporous hydrogels are described in greater detail in US Patent No. 6,875,232 entitled Corneal Implant and Method of Manufacture.

TABLE 1 represents example values ​​for one embodiment of a 5.0mm diameter lens 100 having a given diopter. These example values ​​are for illustration purposes only and in no way limit the implanted lens 100 to these or similar values ​​alone.

TABLE 1

<td>Diopter</td><td> +2,25</td>

<td>Lens Diameter 112 (mm)</td><td> 5,00</td>

<td>Corrector diameter 114 (mm)</td><td> 4,90</td>

<td>Rear Radius 107 (mm)</td><td> 7,50</td>

<td>Center thickness 140 (mm)</td><td> 0,030</td>

<td>Bevel Radius 124 (mm)</td><td> 5,500</td>

<td>Edge radius 126 (mm)</td><td> 0,025</td>

<td>Edge thickness 130 (mm)</td><td> 0,010</td>

<td>Slope angle 132 of edge (degrees)</td><td> 50</td>

The values ​​of edge thickness 130, edge radius 126, edge slope angle 132, and chamfer radius 124 are interdependent and based on the desired correction values, the overall lens diameter 112, the diameter of the correction portion 122, and the shape of the anterior surface 102 and the posterior surface 103. Preferably, a lens diameter 112 in the range of about 1-10mm with a diameter of the correcting portion 114 of about 0.5mm or greater will have an edge thickness less than or equal to about 0.015mm, an edge radius 126 in the range of about 0.001-1 mm, an edge slope angle 132 between 0 and 90 degrees, and a bevel radius 124 in the range of about 1-10 mm. These ranges are for illustrative purposes only and in no way limit the embodiments described herein.

It should be noted that the modified rim described herein can be used with any implantable lens type, shape, or configuration. For example, lens 100 can be either an embedded corneal implant or an overlay corneal implant. Lens 100 can be configured to treat any visual defect including, but not limited to, myopia, hyperopia, astigmatism, and presbyopia. Lens 100 can also be configured to treat any combination of visual defects including, but not limited to, presbyopia with myopia or

ES 2 550 488 T3 hyperopia and presbyopia with astigmatism. The overall external profile 119 of lens 100 can have any shape including, but not limited to, circular, elliptical, irregular, multi-sided, and shapes having an internal aperture. The surface of the outer edge 104 can be configured with protrusions such as fasteners and the like. Also, the lens body 101 can be manufactured from one or more different materials having any desired refractive index. Additionally, as will be described in greater detail below, the correcting portion 122 of the anterior surface 102 may be substantially spherical with or without multiple focal zones, substantially aspherical with or without multiple aspherical surfaces, or any combination, and the like. As used herein, the term is substantially intended to broaden the modified term. For example, a substantially spherical surface does not have to be perfectly spherical, but can include non-spherical variations or errors and the like to a sufficient degree for implementation.

Figures 4-9 are cross-sectional views depicting additional examples of lens 100 taken along line 1-1 in region 111 of Figure 1B. In the example depicted in Figure 4, the correcting portion 122 of the anterior surface 102 is substantially aspherical. The rate of curvature of aspherical surfaces typically decreases or increases as the surface progresses outward toward the surface of the outer edge 104. In this example, the rate of curvature of the aspherical surface 122 is decreased so that the surface is flatter near the surface of the outer edge 104 than near the vertex 105 (not shown). Anterior surface 102 and posterior surface 103 diverge as surfaces 102-103 progress radially outward from apex 105 (not shown) toward interface 123. From interface 123 to interface 125, the radius of bevel 124 preferably converges toward rear surface 103. Similarly, from interface 125 to interface 127, the radius of edge 126 also preferably converges toward rear surface 103.

The beveled portion 124 of the front surface 102 can be flat or curved or in any other desired shape. For example, in Figures 2C-E, the beveled portion 124 is spherically curved, however, it should be noted that any type of curve can be used. In the example depicted in Figure 5, the beveled portion 124 is flat. Similarly, the first and second edge surface portions 126 and 128 can be flat or curved or in any other desired shape. For example, in Figures 2C-E, the radius of edge 126 is substantially spherically curved and the second portion of the surface of edge 128 is curved at a variable rate. In the example shown in Figure 6 the first portion of the edge surface 126 is flat while in the example of Figure 7 the second portion of the edge surface 128 is flat. Any combination of flat and curved surfaces can be implemented. For example, in Figure 8, the beveled portion 124 and the first and second edge surface portions 126 and 128 are all flat. Also, the edge surface 104 can be implemented in any desired manner. For example, in the embodiment of Figure 9, the surface of edge 104 is flat and oriented only in the Z direction.

Figure 10A is a top-down view showing another example lens 100 having a ring-like shape. In this case, the lens 100 includes an inner aperture 302 and an inner edge surface 304. Figure 10B is a cross-sectional view of the lens 100 depicted in Figure 10A taken along line 2-2. In this case, it can be seen that the front surface 102 also includes an internal bevel portion 306 located between the correcting portion 122 and the internal edge surface 304. Like the external edge surface 104, the internal edge surface 304 includes the first portion. 308 and the second portion 310 which, in this example, are both curved. Beveled portion 306 abuts correcting portion 122 at interface 305 and first portion 308 abuts beveled portion 306 at interface 307. Second portion 310 abuts first portion 308 at interface 309 and abuts rear surface 103 of interface 311. It should be noted that edge surface 304 and chamfered portion 306, like edge surface 104 and chamfered portion 124 described above, can be shaped or configured in any desired manner. Lenses 100 of the type described in Figures 10A-B are described in greater detail in US 2005/0119738 A1, entitled Myopic Corneal Ring with Central Accommodating Portion and filed January 11, 2005.

As mentioned above, the lens 100 with the modified edge region as described herein can also be implemented as a multifocal lens. Figure 11A is a perspective view depicting an example of implantable lens 100 configured to provide multifocal correction. In this case, lens 100 includes two correction regions 402 and 404 each of which has a different refractive index. Different refractive indices in each region allow correction of visual defects at different distance intervals. For example, the refractive indices of regions 402 and 404 can be predetermined such that region 402 provides refractive correction over relatively close distances while region 404 provides correction over relatively far distances, or vice versa. Any combination and number of two or more correcting regions can be used. Similarly, any refractive index can be used, including refractive indices that are substantially similar to cornea 206 (approximately 1.36-1.39) and refractive indices that are greater than or less than cornea 206.

Figure 11B is a top-down view depicting this example lens 100 taken along direction 410. In this example, lens 100 has an apex 105, a generally circular outer edge profile 409, and regions 402 and 404 having diameters 406 and 408, respectively. The transition between regions 402 and 404 is referred to as interface 403. In this case, regions 402 and 403 are arranged as generally concentric circular regions. It should be noted that regions 402 and 403 can be arranged in any

ES 2 550 488 T3 desired manner, such as eccentric, hemispherical, irregular and the like. Likewise, any number of two or more regions can be implemented with any number or none of those regions that are integrally coupled to each other.

Figure 11C is a cross-sectional view depicting the example of Figure 11B taken on line 3-3. In this case, the correcting portion 122 of the front surface 102 is substantially spherical and has a radius of curvature 106 and a rear surface 103 that is also substantially spherical that has a radius of curvature 107. Adjusting these radii 106-107 in conjunction with selecting the appropriate refractive index for regions 402-404 can provide the appropriate diopter values ​​for each region to treat a given individual. Figure 11D is an enlarged cross-sectional view of this example lens 100, showing region 411 of Figure 11C in greater detail. In this example, similar to the example depicted in Figure 2D, the lens 100 includes the radius of the bevel 124, the radius of the edge 126, and the second portion of the surface of the curved edge 128.

To provide different refractive indices, one of example regions 402 and 404 are made from different materials integrally coupled together at interface 403. For example, each region 402 and 404 can be made from different microporous hydrogel materials. In one example, lens 100 is manufactured by first forming a solid polymeric cylindrical core 502, such as that depicted in Figure 12A, corresponding to region 402 and having approximately the same diameter as diameter 406 of region 402. This core may then be surrounded by a monomeric solution 503 in a manner similar to that depicted in Figure 12B. The polymeric core 502 is preferably at least slightly soluble in the monomeric solution 503. The monomeric solution 503 can then be polymerized to form the polymeric cylindrical region 504 surrounding the inner core 502 as depicted in Figure 12C. The outer region 504 preferably corresponds to the region 404 and has approximately the same diameter or a slightly larger diameter than the diameter 408 of the region 404. The inner core 502 and the outer region 504 together form a lens core 506, from which one or more lenses can be manufactured, such as, for example, by separating the core 506 into disc-shaped buttons 508, as depicted in Fig. Figure 12D. Each individual button can be machined or cut into a desired shape and further processed (eg, softened, hydrated, etc.) to form an individual lens body 101.

As mentioned above, the polymeric core 502 is preferably at least slightly soluble in the monomeric solution 503. This is so that the solution 503 can dissolve the outer surface of the core 502 and become interdispersed and mixed with the dissolved portion of the core. 502. Once solution 503 has polymerized and solidified, an interface region 505 can be formed between cores 502 and 504, where the different polymers or cores 502 and 504 together form an interpenetrating network. This interface region corresponds to interface region 430 in Figure 13 below and integrally couples regions 402 and 404 to each other.

Figure 13 is a cross-sectional view of an example lens 100 having interface region 430. By integrally coupling regions 402 and 404 to each other, the region significantly reduces the risk of regions 402 and 404 separating, such as this may be the case when adhesive is used to bond regions 402 and 404. Additionally, interface region 430 may have a refractive index or range of refractive indices between the refractive indices of regions 402 and 404. As a result, interface region 430 may act as an optical transition within regions 402. and 404 and adding a third multifocal region to lens 100. This can eliminate an immediate or sharp transition between the refractive indices of regions 402 and 404 that could result in visual defects such as halos or glare.

The width 420 of the interface region 430 can be varied as desired. For example, to generate a broader interface region 430, the monomeric solution 504 can be left in contact with the inner core 502 for a longer period of time prior to polymerization or the solubility of the inner polymeric core 502 in the monomeric solution 504. can be increased. In general, the wider interface region 430, the more conspicuous region 430 will be to the subject as a multifocal region.

It should be noted that lens 100 can be manufactured in any way and is not limited to the example described with respect to Figures 12A-D. Other polymerization methods known in the art including, but not limited to, dip coating, spinning, casting, and polymerization of prepolymers can be used in the formation of regions 402 and 404.

In another example, each region 402 and 404 is configured with varying levels of permeability. For example, region 402 may have a level of fluid and nutrient permeability that is sufficient to substantially support cornea 206 while region 404 may have a permeability to any fluid or fluids and nutrients that is relatively less than region 402, including be totally impervious to fluids and nutrients. This allows the use of more types of materials that have a wider range of refractive indices and / or structural characteristics.

IS 2 550 488 T3

To allow sufficient fluid / nutrient transfer to support cornea 206, the size of any impermeable region is preferably minimized. For example, any circular central region, similar to the example of region 402 described with respect to Figure 11b, that is fluid and nutrient impermeable is preferably less than about 3mm in diameter (406 diameter) or about 76.1mm.². However, it should be noted that lens 100 is not limited to any one of the total impermeable surface area, with the size and surface area of ​​any impermeable region being dependent on the shape of the region and the relative level of permeability of any adjoining region. For example, an example lens 100 that has many concentric regions arranged in a target pattern, where the regions alternate between permeable and impermeable, could allow a total surface area of ​​impermeable regions that is greater than 7.1 mm.².

Figure 14A is a top-down view depicting another example of a multifocal lens 100 where the correcting portion 122 of the anterior surface 102 includes surfaces 602 and 604 that have different rates of curvature. Surfaces 602 and 604 have diameters 610 and 612, respectively. Figure 14B is a cross-sectional view and another example of lens 100 taken along line 4-4 of Figure 14A. In this case, surfaces 602 and 604 are each substantially spherical, but have different radii of curvature 605 and 606 respectively. The abutment between surface 602 and 604 is referred to as interface 603. Each surface 602 and 604 can be configured with a different diopter value to correct for different distance ranges (eg, near-far, far-near, etc.). TABLE 2 shows example values ​​for three examples of a 5.0 millimeter (mm) diameter lens 100 having multiple spherical surfaces 602 and 604 similar to those depicted in Figure 14B. Each of the three examples provides a different degree of correction for relatively far distances (sphere) and relatively close distances (tda). These corrective values ​​are displayed in sphere diopter / tda diopter format. All of these example values ​​are for illustration purposes only and in no way limit the implantable lens 100 to only these or similar values.

TABLE 2

<td>Parameter</td><td> 0,00/1,75</td><td> 0,00/2,00</td><td> 0,00/2,25</td>

<td>Lens Diameter 112 (mm)</td><td> 5,00</td><td> 5,00</td><td> 5,00</td>

<td>Rear Radius 107 (mm)</td><td> 7,50</td><td> 7,50</td><td> 7,50</td>

<td>Center thickness 140 (mm)</td><td> 0,020</td><td> 0,021</td><td> 0,022</td>

<td>Bevel Radius 124 (mm)</td><td> 4,770</td><td> 4,770</td><td> 4,770</td>

<td>Edge radius 126 (mm)</td><td> 0,025</td><td> 0,050</td><td> 0,050</td>

<td>Edge thickness 130 (mm)</td><td> 0,010</td><td> 0,010</td><td> 0,010</td>

<td>Slope angle 132 of edge (degrees)</td><td> 45</td><td> 45</td><td> 45</td>

<td colspan="4">Spherical surface 602</td>

<td>Diameter 610 (mm)</td><td> 2,00</td><td> 2,00</td><td> 2,00</td>

<td>Radius 605 (mm)</td><td> 7,252</td><td> 7,217</td><td> 7,182</td>

<td colspan="4">Spherical surface 604</td>

<td>Diameter 612 (mm)</td><td> 4,90</td><td> 4,90</td><td> 4,90</td>

<td>Radius 606 (mm)</td><td> 7,505</td><td> 7,505</td><td> 7,505</td>

Figure 14C is a cross-sectional view of another example lens 100 taken along line 4-4 of Figure 14A. In this case, each of the surfaces 602 and 604 is substantially aspherical. Each of the surfaces 602 and 604 has a radius 614 and 616, measured respectively along the central axis 118. Radius 116 is measured along central axis 118 from vertex 622 to an imaginary position on surface 604 corresponding to the point where surface 604 would intersect with central axis 118 if surface 604 were to extend all the way central axis 118, as indicated by dashed line 620.

Because aspherical surfaces are inherently multifocal, the inclusion of multiple aspherical surfaces provides an added dimension of multifocality to the lens 100. For example, surface 602 can have any asphericity (Q) and can provide a range of diopter values ​​that varies in any proportion from vertex 105 to interface 603 and that can be configured to provide correction over relatively close distances, while surface 604 can have a range of diopter values ​​that varies at any rate from interface 603 to interface 123 and can be configured to provide correction over relatively far distances. One skilled in the art will readily recognize that each surface 602 and 604 can have any range of diopter values ​​and provide correction over any distance.

IS 2 550 488 T3

TABLE 3 shows example values ​​for an example of a 5.0 millimeter (mm) diameter lens 100 having multiple aspherical surfaces 602 and 604 similar to that depicted in Figure 14C. Each of the three examples provides a different degree of correction for relatively far distances and relatively close distances. All of these example values ​​are for illustration purposes only and in no way limit the implantable lens 100 solely to these or similar values.

TABLE 3

<td>Parameter</td><td>0.00 / 1.75 D</td><td>0.00 / 2.00 D</td><td>0.00 / 2.25 D</td>

<td>Lens Diameter 112 (mm)</td><td> 5,00</td><td> 5,00</td><td> 5,00</td>

<td>Rear Radius 107 (mm)</td><td> 7,50</td><td> 7,50</td><td> 7,50</td>

<td>Center thickness 140 (mm)</td><td> 0,020</td><td> 0,021</td><td> 0,022</td>

<td>Bevel Radius 124 (mm)</td><td> 4,770</td><td> 4,770</td><td> 4,770</td>

<td>Edge radius 126 (mm)</td><td> 0,025</td><td> 0,025</td><td> 0,025</td>

<td>Edge thickness 130 (mm)</td><td> 0,010</td><td> 0,010</td><td> 0,010</td>

<td>Slope angle 132 of edge (degrees)</td><td> 45</td><td> 45</td><td> 45</td>

<td colspan="4">Spherical surface 602</td>

<td>Diameter 610 (mm)</td><td> 2,00</td><td> 2,00</td><td> 2,00</td>

<td>Radius 614 (mm)</td><td> 7,217</td><td> 7,182</td><td> 7,148</td>

<td>Asphericity (Q)</td><td> -1,015</td><td> -1,001</td><td> -0,987</td>

<td colspan="4">Aspherical surface 604</td>

<td>Diameter 612 (mm)</td><td> 4,90</td><td> 4,90</td><td> 4,90</td>

<td>Radius 616 (mm)</td><td> 7,452</td><td> 7,452</td><td> 7,452</td>

<td>Asphericity (Q)</td><td> -0,225</td><td> -0,225</td><td> -0,225</td>

Although not shown in Figures 14A-C, lens 100 may have one or more transition surfaces at interface 603 that provide a smoother transition between surfaces 602 and 604, since abrupt transitions can stimulate adverse tissue reactions. Edge surface 104 and beveled portion 124 are also not shown in Figures 14A-C, but may be included as desired. Also, it should be noted that lens 100 can have any number of multifocal surfaces or refractive regions as desired. The substantially spherical or substantially aspherical multifocal surfaces 602 and 604 may also be arranged in any desired manner including, but not limited to, eccentric, hemispherical, irregular, or the like.

In the above specification, the invention has been described with reference to specific embodiments thereof. However, it would be apparent that various modifications and changes can be made therein without departing from the scope of the claims.