Patent Publication Number: US-2011054603-A1

Title: Intraocular lens

Description:
This application is a continuation of U.S. Nonprovisional patent application Ser. No. 11/862,244 filed on Sep. 27, 2007. This invention relates to intraocular lenses (IOLs) and more particularly to single piece IOLs. 
    
    
     BACKGROUND OF THE INVENTION 
     The human eye in its simplest terms functions to provide vision by transmitting and refracting light through a clear outer portion called the cornea, and further focusing the image by way of the lens onto the retina at the back of the eye. The quality of the focused image depends on many factors including the size, shape and length of the eye, and the shape and transparency of the cornea and lens. 
     When trauma, age or disease cause the lens to become less transparent, vision deteriorates because of the diminished light which can be transmitted to the retina. This deficiency in the lens of the eye is medically known as a cataract. The treatment for this condition is surgical removal of the lens and implantation of an artificial lens or IOL. 
     While early IOLs were made from hard plastic, such as polymethylmethacrylate (PMMA), soft, foldable IOLs made from silicone, soft acrylics and hydrogels have become increasingly popular because of the ability to fold or roll these soft lenses and insert them through a smaller incision. Several methods of rolling or folding the lenses are used. One popular method is an injector cartridge that folds the lenses and provides a relatively small diameter lumen through which the lens may be pushed into the eye, usually by a soft tip plunger. The most commonly used injector cartridge design is illustrated in U.S. Pat. No. 4,681,102 (Bartell), and includes a split, longitudinally hinged cartridge. Similar designs are illustrated in U.S. Pat. Nos. 5,494,484 and 5,499,987 (Feingold) and 5,616,148 and 5,620,450 (Eagles, et al.). In an attempt to avoid the claims of U.S. Pat. No. 4,681,102, several solid cartridges have been investigated, see for example U.S. Pat. No. 5,275,604 (Rheinish, et al.), 5,653,715 (Reich, et al.), and U.S. Pat. No. 5,947,976 (Van Noy, et al). 
     These prior art devices were intended to inject an IOL into the posterior chamber of an aphakic eye through a relatively large (approximately 3.0 mm or larger) incision. Surgical techniques and IOLs have been developed that allow the entire surgical procedure to be performed through much smaller incisions, 2.4 mm and smaller. As a result, IOLs capable of being rolled or folded small enough to fit through such a small incision are desirable. To accomplish this goal, the IOL must be made thinner, or debulked, yet still have a refractive power of 30 D or more. Thinning the center of the optic thus requires thinning the edge of the optic as well. Disadvantages of IOLs with such thin cross-sections, particularly when made from a soft, foldable material, are that the optic edge is very fragile and easily damaged during insertion, particularly when a plungered insertion device is used. In addition, the haptic/optic junction is very thin and weak and such lenses can become unstable in the eye. One solution to this stability problem is to implant a stabilizing ring in the capsular bag and locate the IOL within this ring. Such a construction is illustrated in US Patent Publication No. 2007/0010881 (Soye, et al.). While a two part lens system is effective in providing a very thin, stable IOL that can be implanted through a very small incision, the two components can be more difficult to implant that a single component lens. 
     Accordingly, a need continues to exist for a single-piece, stable IOL that can be implanted through a very small incision. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention improves upon prior art by providing an IOL having a depressed inner optic area and a thickened or raised peripheral outer lip or rim integrally formed with the optic. Such a design reduces the mass of the IOL, making the lens easier to insert in a very small incision, without damaging the optic or compromising the stability of the IOL. 
     It is accordingly an objective of the present invention to provide a stable IOL. 
     It is a further objective of the present invention to provide a stable IOL that is more easily inserted through a very small incision in the eye. 
     It is yet a further objective of the present invention to provide an IOL having a depressed inner optic area and a thickened or raised peripheral outer lip or rim integrally formed with the optic. 
     Other objectives, features and advantages of the present invention will become apparent with reference to the drawings, and the following description of the drawings and claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an enlarged top plan view of the IOL of the present invention. 
         FIG. 2  is an enlarged cross-sectional view of a first embodiment of the IOL of the present invention taken at line A-A in  FIG. 1 . 
         FIG. 3  is an enlarged cross-sectional view of a second embodiment of the IOL of the present invention taken at line A-A in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     IOL  10  of the present invention generally includes optic  12  and at least two haptics  14 . IOL  10  may have an overall length of any suitable dimension, with between 10.5 millimeters (mm) and 14.0 mm being preferred and 12.5 mm being most preferred. Optic  12  and haptics  14  are molded in a single piece from the same material. The material used to make IOL  10  may be any soft biocompatible material capable of being folded. Suitable materials are the hydrogel, silicone or soft acrylic materials described in U.S. Pat. Nos. 5,411,553 (Gerace, et al.), 5,403,901 (Namdaran, et al.), 5,359,021 (Weinschenk, Ill., et al.), 5,236,970 (Christ, et al.), 5,141,507 (Parekh) and 4,834,750 (Gupta). Optic  12  has an anterior side  24  and a posterior side  26  and may be of any suitable diameter, with between 4.5 mm and 7.0 mm being preferred and between 5.5 mm to 6.0 mm being most preferred. Optic  12  may also be elliptical or oval. As shown in the following table, the maximum thickness of optic  12  will vary depending on the dioptic power desired and the index of refraction for the material used, but for with edge  18  being 0.1 mm thick and rim  30  or  30 ′ being approximately 0.30 mm thick, the central thickness of optic  12  generally will be between 0.19 mm and 1.19 mm for a power range of between 6 D and 71 D, but for a substantial portion of the population, a central thickness of 0.39 mm or less is preferred with between 0.37 mm and 0.39 mm being most preferred. 
                                             Power (D)   Central Optic Thickness (mm)                                                    71.00   1.19           61.25   1.02           39.25   0.68           24.25   0.45           21.75   0.41           20.75   0.40           19.75   0.39           19.00   0.37           6.25   0.19                        
The principal design criteria for IOL  10  is to minimize the thickness of optic  12  for any given diameter and power of optic  12  so as to minimizing the size of the surgical incision required to implant IOL  10 . The material used to make optic  12  may be modified to absorb ultraviolet radiation, or any other desired radiation wavelength, such as blue or violet light.
 
     As best seen in  FIGS. 2 and 3 , optic  12  contains peripheral lip or rim  30  or  30 ′, respectively, integrally formed as part of optic  12  and extending substantially or complete around peripheral edge  18  of optic  12 . Rim  30  may be centered axially on optic  12 , as seen in  FIG. 2 , or rim  30 ′ may be axially located anteriorly on optic  12 . Such a construction allows the reduction in thickness of optic  12  while maintaining the stability of IOL  10  in the eye. 
     While certain embodiments of the present invention have been described above, these descriptions are given for purposes of illustration and explanation. Variations, changes, modifications and departures from the systems and methods disclosed above may be adopted without departure from the scope or spirit of the present invention.