Abstract:
An IOL implantable in an eye comprising an optic having an optical portion for directing light toward the retina of the eye and a cell barrier portion for inhibiting cell growth from the eye in front of or in back of the optical portion. The cell barrier portion circumscribes the optical portion, is incapable of focusing light on the retina and includes an irregularly configured structure, for example, irregular grooves. At least one elongated fixation member is coupled to the optic for use in fixing the optic in the eye.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation application of and claims priority to U.S. application Ser. No. 11/775,516, filed Jul. 10, 2007, which is a continuation application of U.S. application Ser. No. 11/429,461, filed May 4, 2006, now abandoned, which is a continuation application of U.S. application Ser. No. 10/851,757, filed on May 21, 2004, now abandoned, which is a continuation application of U.S. application Ser. No. 10/421,102, filed Apr. 23, 2003, now abandoned, which is a continuation application of U.S. application Ser. No. 10/099,774, filed Mar. 15, 2002, now abandoned, which is a continuation application of U.S. application Ser. No. 09/606,458, filed Jun. 29, 2000, now abandoned, which is a continuation application of U.S. application Ser. No. 09/205,135, filed Dec. 3, 1998, now abandoned, which is a continuation application of U.S. application Ser. No. 08/919,292, filed Aug. 28, 1997, now abandoned, which is a continuation application of U.S. application Ser. No. 08/703,470, filed Aug. 27, 1996, now abandoned, which claims priority to U.S. application Ser. No. 08/627,723, filed Apr. 2, 1996, now issued U.S. Pat. No. 5,693,094, which claims priority from U.S. application Ser. No. 08/437,656, filed May 9, 1995, now issued U.S. Pat. No. 5,549,670. The disclosure of the prior applications is considered part of (and are incorporated by reference in) the disclosure of this application. 
     
    
     BACKGROUND 
       [0002]    This invention relates to intraocular lenses and in particular to intraocular lenses (IOL&#39;s) which reduce secondary opacification. 
         [0003]    An intraocular lens is commonly used to replace the natural lens of the human eye when warranted by medical conditions. It is common practice to implant an IOL in a region of the eye known as the capsular bag or posterior capsule. 
         [0004]    One problem that is experienced with many IOL&#39;s following their implantation is that cells from the eye, particularly lens epithelial cells from the capsular bag, lend to grow on the capsular bag in front of and/or in back of the optical portion of the IOL. This tends to block the optical portion of the IOL and to impair vision. 
         [0005]    A common treatment for this condition is to use a laser to destroy the cells and a central region of the capsular bag. Although this treatment is effective, the laser is expensive and is not available throughout the world. There is also cost associated with the laser treatment as well as some patient inconvenience and risk of complications, Finally, the laser treatment may affect the performance of some IOL&#39;s. 
         [0006]    Davenport U.S. Pat. No. 4,743,254 discloses an IOL which includes glare reducing sections on the opposite sides of an optic. These glare reducing sections are fully or partially opaque and their surfaces are not smooth. It has been observed that cell migration across the glare reducing sections appears to be reduced. A similar result has been observed in a plate IOL in which a plate, which is used as a haptic for fixing the IOL in the eye, surrounds the optic. Specifically cell migration across the plate, which has a somewhat textured surface, appears to be reduced. 
         [0007]    Kelman U.S. Pat. No. 4,808,181 discloses an IOL including a lens assembly having an anterior surface formation and a posterior surface formation. At least a portion of the posterior surface formation constitutes a planar contact region adapted to seat against the posterior capsule of the eye to permanently anchor the lens assembly. The contact region is provided with a roughened surface area defined by a series of ordered narrow linear depressions extending transverse of the plane of the contact region. This patent teaches that these ordered narrow linear depressions accelerate adhesion and enhance anchoring of the tissue of the posterior capsule to the lens assembly. This patent is not concerned with secondary opacification and provides no solution to this problem. 
       SUMMARY 
       [0008]    This invention provides an IOL which is believed to solve the secondary opacification problem discussed above. With this invention, an optical portion, which is adapted to be placed in the capsular bag of an eye, directs light toward the retina of the eye, and a cell barrier portion circumscribes the optical portion. With this construction, the optical portion serves the normal function of directing and focusing light at or near the retina. The cell barrier portion inhibits cell growth from the eye, for example, from the capsular bag, in front of and/or in back of (behind) the optical portion. The optical portion and the cell barrier portion may be considered as being portions of the optic. 
         [0009]    The cell barrier portion of the optic circumscribes the optical portion so as to not leave any path available for the migration of cells in front of or in back of the optical portion. The cell barrier portion is constructed so as to be incapable of or ineffective in focusing light on the retina. The cell barrier portion is preferably partially or wholly opaque to eliminate light scattering. 
         [0010]    At least one fixation member, preferably an elongated fixation member, is coupled to, and preferably extends outwardly from, the optic for use in fixing the optic in the eye. Viewed from a different perspective, a structure other than the cell barrier portion is employed for fixing the optic in the eye. Such structure may include one or more fixation members of various different configurations coupled to the optic. The fixation members may be separate members attached to the optic or members which are integral with the optic, and they may comprise elongated filaments or one or more wider plate or plate-like members. 
         [0011]    The cell barrier portion may be of any construction which performs the function of inhibiting cell growth from the eye in front of or in back of the optical portion. In this regard, the cell barrier portion may include an irregularly configured structure or surface feature, such as an irregularly roughened or textured surface region and/or one or more annular grooves which are at least partially defined by irregular surfaces. 
         [0012]    As used herein, the terms “irregular” or “irregularly” refer to a thing, for example, an irregularly roughened surface region, or series of things, for example, irregular surfaces, which do not have a consistent order, pattern or configuration. In one embodiment, these terms refer to a thing or series of things which are substantially unordered or which have a pattern or configuration with a significant or substantial degree of randomness, or even substantially complete randomness. In one embodiment, the irregularity in accordance with the present invention is sufficient to result in the irregularly configured structure, present in an otherwise optically clear cell barrier portion to be at least about 50% opaque (that is frosty or hazy), more preferably at least about 80% opaque and still more preferably substantially completely opaque. 
         [0013]    The irregularly configured structure or surface feature of the cell barrier portion preferably has a radial dimension of no more than about 2 mm, more preferably no more than about 0.75 mm and still more preferably no more that about 0.25 mm. If the cell barrier portion includes an annular groove, the groove preferably has a maximum width and a maximum depth each no greater than about 0.02 mm. In one preferred construction, the cell barrier portion includes at least about 20 annular grooves. 
         [0014]    The optic has anterior and posterior faces. The irregularly configured structure, for example, surface roughening or texturing and/or grooves, may be provided on any surface or surfaces along which the cells may migrate and completely circumscribes the optical portion. Preferably, the irregularly configured structure is provided at least on the posterior face and/or anterior face of the optic in the cell barrier portion. 
         [0015]    The irregularly configured structure or surface feature can be included in/on the cell barrier portion using any suitable technique or methodology. Of course, it is important that this structure or surface feature be sufficiently irregular to achieve the desired inhibition of cell migration or cell growth so that the risk of secondary opacification is reduced. The technique or methodology chosen to include this structure or surface feature should take this basic criterion into account. This structure or surface feature can be formed during the initial formation, for example, the molding, of the cell barrier portion or optic, or can be included after the cell barrier portion or optic is produced, for example, using a laser, lathe, other mechanical implement and the like. In one particularly useful embodiment, a lathe is employed to form a spiral array of annular grooves defined by irregular surfaces in the cell barrier portion. Cell barrier portions may be processed in a manner similar to the glare reducing sections of Davenport U.S. Pat. No. 4,743,254 to yield fully or partially opaque structures the surfaces of which are irregular and not smooth. The disclosure of this patent is incorporated in its entirety herein by reference. 
         [0016]    The cell barrier portion may be integral with the optical portion, or may be a separate member coupled to the optical portion. Also, the fixation member or members may be integral with the cell barrier portion and/or the optical portion, or may be a separate element or elements, e.g., filament or filaments, coupled to the optical portion or the cell barrier portion. 
         [0017]    The invention, together with additional features and advantages thereof may best be understood by reference to the following description taken in connection with the accompanying illustrative drawings. 
     
    
     
       DESCRIPTION OF DRAWINGS 
         [0018]      FIG. 1  is a plan view of one form of IOL constructed in accordance with the teachings of this invention. 
           [0019]      FIG. 1A  is an elevational view of the IOL shown in  FIG. 1 . 
           [0020]      FIG. 2  is an enlarged fragmentary view of the region generally bounded by the are  2  in  FIG. 1  and showing a more detailed view of the cell barrier portion of the IOL. 
           [0021]      FIG. 3  is an enlarged fragmentary sectional view taken generally along 3-3 of  FIG. 2 . 
           [0022]      FIG. 4  is an enlarged fragmentary sectional view taken generally along line  3 - 3  of  FIG. 2  and showing the growth of cells from the capsular bag of the eye on only a portion of the cell barrier region. 
           [0023]      FIG. 5  is a plan view of a second form of IOL constructed in accordance with the teachings of this invention. 
           [0024]      FIG. 6  is an enlarged fragmentary sectional view taken generally along line  6 - 6  of  FIG. 5 . 
           [0025]      FIG. 7  is a plan view with portions broken away of a third from of IOL constructed in accordance with the teachings of this invention. 
           [0026]      FIG. 8  is an enlarged fragmentary sectional view taken generally along line  8 - 8  and illustrating another construction of the cell barrier portion. 
       
    
    
     DETAILED DESCRIPTION 
       [0027]      FIGS. 1 and 1A  show an IOL  11  which generally comprises an optic  13  and fixation members  15  and  17 . In this embodiment, the optic  13  may be considered as including an optical portion  19  for focusing light on or near the retina of the eye and a cell barrier portion  21  circumscribing the optical portion and being incapable of focusing light on the retina. Optical axis  22  passes through the center of optic  13  in a direction generally transverse to the plane of the optic. 
         [0028]    In this embodiment, the optic  13  is circular in plan and biconvex; however, this is purely illustrative as other configurations and shapes may be employed. The optic  13  may be constructed of any of the commonly employed materials commonly used for rigid optics, such as polymethylmethacrylate (PMMA), or commonly used for resiliently deformable optics, such as silicone polymeric materials, acrylic polymeric materials, hydrogel-forming polymeric materials, mixtures thereof and the like. 
         [0029]    The fixation members  15  and  17  in this embodiment are generally C-shaped and are integral with the optic  13 . However, this is purely illustrative as the fixation members  15  and  17  may be of other configurations and/or may be separate members affixed to the optic in any of a variety of conventional ways. 
         [0030]    The optic  13  has an anterior face  23 , a posterior face  25  and a peripheral edge  27 . In this embodiment, the faces  23  and  25  are convex and the peripheral edge  27  is cylindrical, but as indicated above, these shapes are shown only by way of example. 
         [0031]    The optic  13  is designed to be placed in the capsular bag. The diameter of the optic  13  may be conventional, and as such, may be about 6 mm or less. The optical portion  19  performs the normal function of the optic of an IOL, i.e. to appropriately focus light at or near the retina. The optical portion  19  may be monofocal or multifocal. 
         [0032]    In this embodiment, the cell barrier portion  21  is integral with the optical portion  19 . The cell barrier portion  21  is incapable of focusing light on the retina of the eye and includes an irregularly configured structure or surface feature effective to inhibit, and preferably substantially prevent, cell growth radially inwardly across the cell barrier portion. In the embodiment of  FIGS. 1-6 , the cell barrier portion  21  includes a concentric array of annular grooves  29  each of which is at least partially defined by irregular surfaces. Similar arrays of the grooves  29  are in either the anterior face  23  or the posterior face  25 , or both. Although various different arrangements can be employed, in this embodiment the grooves  29  are concentric and substantially equally spaced apart. 
         [0033]    Without wishing to limit the invention to any particular theory of operation, it is believed that grooves  29 , acts to disrupt or otherwise interfere with the process of eye cell, for example, lens epithelial cell, migration or growth so that the cumulative effect of this irregular structure is to significantly reduce, or even eliminate, the migration or growth of cells in front of or in back of the optical portion  19  after IOL  11  is implanted in the eye.  FIG. 4  illustrates that eye cells  30  from the capsular bag  32  do migrate or grow to some extent onto and cover a portion of the cell barrier portion  21 . This limited cell migration is advantageous in at least assisting or facilitating the effective fixation of IOL  11  in the eye. Thus, the present invention preferably provides for such advantageous limited eye lens epithelial cell migration or growth while preventing excessive cell migration or growth in front of or in back of the optical portion  19 , as shown in  FIG. 4 . 
         [0034]    Another way of viewing the degree of irregularity of the irregularly configured structure, for example, grooves  29 , on cell barrier portion  21  is opacity. The grooves  29  are sufficiently irregular so that the cell barrier portion  21  is substantially completely opaque to the transmission of light. When viewed by the naked eye, cell barrier portion  21  is a white or frosty band on the otherwise optically clear optic  13 . 
         [0035]    Preferably, the radial dimension of the cell barrier portion  21  is no greater than about 2 mm, and more preferably no greater than 0.25 mm. 
         [0036]    In the embodiment shown in  FIGS. 1 to 4 , the number of grooves  29  is about 50 to about 100. In order to obtain an advantageous degree of cell migration inhibition, it is preferred that the number of grooves included in cell barrier portion  2  be at least about 20, although fewer grooves can provide some useful benefits. 
         [0037]    The grooves  29  are located wherever it is desired to inhibit cell migration. In the present embodiment, the grooves  29  are placed on both the anterior face  23  and the posterior face  25  so that the cell barrier portion  21  is on both faces of the optic  13 . However, the cell barrier portion can be eliminated from a particular face if it is determined that cell migration in front of that face is not likely to occur. 
         [0038]    The IOL  11  can be implanted in the capsular bag of the eye in accordance with conventional techniques. When so implanted, the cell barrier portion  21  defines a radially relatively narrow annular barrier for inhibiting cell growth radially inwardly in front of or in back of the optical portion  19  where the cells could cause secondary opacification. 
         [0039]    The present invention is applicable to IOLs including a hard or rigid optic, such as the optics made from PMMA, and those which include a foldable or deformable optic, such as optics comprising silicone polymeric materials, other acrylic polymeric materials, hydrogel-forming polymeric materials, such as polyhydro-xyethylmethacrylate (poly HEM A), and the like. Such foldable/deformable optics are particularly advantageous since they can be inserted into the eye through a small incision. The fixation members  15  and  17 , are flexible and strandlike or filaments so that they can be easily inserted into the eye. The fixation members  15  and  17  can be formed integrally with the optic  13  or can be separately coupled to the optic. 
         [0040]      FIGS. 5 and 6  show an IOL  11   a  which is identical to the IOL  11  in all respects not shown or described herein. Portions of the IOL  11   a  corresponding to portions of the IOL  11  are designated by corresponding reference numerals followed by the letter a. 
         [0041]    The only difference between the IOL&#39;s  11  and  11   a  is that in the IOL  11   a  the grooves  29  are replaced with an irregularly roughened or textured surface  31 . The cell barrier portion  21   a , in particular the roughened or textured surface  31 , is sufficiently irregular as to be at least partially, and preferably substantially completely, opaque to the &gt; transmission of light. This not only provides cell migration inhibition, but also avoids glare from the interaction of light with the cell barrier portion  21   a . The textured surface  31  may be textured or roughened in any of a variety of ways including machining as with a lathe, chemical etching, abrading or the like. If the optic  13   a  is molded, as for example when it is constructed of silicone polymeric material or other soft foldable material, the texturing or roughening of the textured surface  31  may be imparted by the mold. 
         [0042]    The degree of irregularity of the roughening of the surface  31  should be sufficient to enable the textured surface to perform the inhibition of cell migration function. 
         [0043]      FIGS. 7 and 8  show an IOL  11   b  which is identical to the IOL  11  in all respects not shown or described herein. Portions of the IOL  11   b  corresponding to portions of the IOL  11  are designated by corresponding reference numerals follows by the letter b. 
         [0044]    There are two primary differences between the IOL&#39;s  11   b  and  11 . First, in the IOL  11   b , the fixation members  15   b  and  17   b  are separate strands or filaments which are attached to the optic  13   b  in an suitable conventional manner. Secondly, the cell barrier portion  21   b  is in the form of a separate member coupled to the optical portion  19   b.    
         [0045]    In this embodiment, the cell barrier  21   b  includes spaced legs  33  joined by a web  35 . The legs  33  engage the faces  23   b  and  25   b , respectively, and the web  35  confronts and engages the peripheral edge  27   b . The cell barrier portion  21   b  is annular and extends completely around the optical portion  19   b  and is mounted on the optical portion in a manner similar to a tire. The cell barrier portion  21   b  may have a radial width of up to about 2 mm or about 1 mm, for example, about 0.25 mm. 
         [0046]    While this invention has been described with respect to various specific examples and embodiments, it is to be understood that the invention is not limited thereto and that it can be variously practiced within the scope of the following claims.