Pre-stressed haptic for accommodating intraocular lens

Abstract

An intraocular lens is disclosed, with an optic that changes shape in response to a deforming force exerted by the zonules of the eye. A haptic supports the optic around its equator and couples the optic to the capsular bag of the eye. The haptic may be pre-stressed before the optic is placed within it. After such placement, the pre-stress may be relieved, and the haptic may produce stress in the optic. The pre-stress may produce a radial tension or a radial compression in the optic. Alternatively, once the optic is placed within the haptic, both may undergo a process that changes the size and/or shape of one with respect to the other, causing a stress within the optic. This process may produce a radial tension or a radial compression in the optic. The haptic may include an annular ring having outer and inner diameters that may depend on the stiffness of the haptic.

1 . An intraocular lens for implantation into a capsular hag of an eye, comprising:
 a stressed optic, and   a haptic for coupling the optic to the capsular bag;   wherein the haptic stresses the stressed optic when the intraocular lens is in a natural state.   
     
     
         2 . The intraocular lens of  claim 1 , wherein the stressed optic is under tension and the haptic is under compression when the intraocular lens is in a natural state. 
     
     
         3 . The intraocular lens of  claim 2 , wherein the tension of the stressed optic and the compression of the haptic are radial and coaxial. 
     
     
         4 . The intraocular lens of  claim 1 , wherein the stressed optic is under compression and the haptic is under tension when the intraocular lens is in a natural state. 
     
     
         5 . The intraocular lens of  claim 4 , wherein the compression of the stressed optic and the tension of the haptic are radial and coaxial. 
     
     
         6 . An intraocular lens for implantation into a capsular bag of an eye, comprising:
 an optic; and   a haptic for coupling the optic to the capsular bag;   wherein the optic is under tension when the intraocular lens is in a natural state.   
     
     
         7 . The intraocular lens of  claim 6 , wherein the haptic is under compression when the intraocular lens is in a natural state. 
     
     
         8 . The intraocular lens of  claim 7 , wherein the tension in the optic and the compression in the haptic are radial and coaxial. 
     
     
         9 . An intraocular lens for implantation into a capsular bag of an eye, comprising,
 an optic having a periphery; and   an annular ring engaging at least a portion of the periphery of the optic for coupling the optic to the capsular bag;   wherein the annular ring stresses the optic in the absence of an external compressive force on the annular ring.   
     
     
         10 . The intraocular lens of  claim 9 , wherein the stress on the optic is tension. 
     
     
         11 . The intraocular lens of  claim 9 , wherein the stress on the optic is radial. 
     
     
         12 . The intraocular lens of  claim 9 , wherein the annular ring has an inner radius and an outer radius, the inner and outer radii being in a ratio that relates to a stiffness of the haptic. 
     
     
         13 . An intraocular lens for implantation into a capsular bag of an eye, comprising:
 an optic having a periphery; and   an annular ring engaging at least a portion of the periphery of the optic for coupling the optic to the capsular bag;   wherein the optic has a uncompressed surface profile in the absence of an external compressive force on the annular ring;   wherein the optic has a compressed surface profile in the presence of an external compressive force on the annular ring; and   wherein the compressed surface profile is more spherical than the uncompressed surface profile.   
     
     
         14 . An intraocular lens for implantation into a capsular bag of an eye, comprising.
 an optic having an equatorial region and a shape, the shape comprising an anterior curvature and a posterior curvature; and   a haptic for coupling the optic to the capsular bag;   wherein the optic can change its shape in response to essentially radial forces exerted by the capsular bag and transmitted to the equatorial region of the optic by the haptic;   wherein the haptic is stiffer than the optic;   wherein the haptic is coaxial with the optic; and   wherein the haptic stresses the optic when the intraocular lens is in a natural state.   
     
     
         15 . The intraocular lens of  claim 14 , wherein the haptic produces tension in the optic when the intraocular lens is in a natural state. 
     
     
         16 . The intraocular lens of  claim 15 , wherein the tension in the optic is radially symmetric. 
     
     
         17 . The intraocular lens of  claim 15 , wherein the tension in the optic is radially asymmetric. 
     
     
         18 . The intraocular lens of  claim 14 , wherein the haptic protrudes into the optic. 
     
     
         19 . The intraocular lens of  claim 14 , wherein the haptic comprises a circumferential ring. 
     
     
         20 . The intraocular lens of  claim 19 , wherein the circumferential ring of the haptic is disposed within the circumference of the optic. 
     
     
         21 . The intraocular lens of  claim 14 , wherein the haptic essentially fills the capsular bag of the eye. 
     
     
         22 . The intraocular lens of  claim 21 , wherein the optic is disaccommodatively biased. 
     
     
         23 . The intraocular lens of  claim 14 , wherein the optic and haptic are both transparent. 
     
     
         24 . The intraocular lens of  claim 14 , wherein the optic and haptic have essentially equal refractive indices. 
     
     
         25 . The intraocular lens of  claim 14 , wherein the optic is made from silicone. 
     
     
         26 . The intraocular lens of  claim 14 , wherein the haptic is made from silicone. 
     
     
         27 . A method for manufacturing an intraocular lens having a haptic, comprising:
 stressing the haptic under an external stress;   placing an optic within the haptic; and   removing the external stress from the haptic,   so that at equilibrium, the optic is internally stressed.   
     
     
         28 . The method of  claim 27 , wherein the stressing step comprises compressing the haptic. 
     
     
         29 . The method of  claim 27 , wherein the stressing step comprises tensing the haptic. 
     
     
         30 . The method of  claim 27 , wherein the stressing step comprises stressing the haptic under a largely radial external stress. 
     
     
         31 . The method of  claim 27 , wherein the stressing step comprises stressing the haptic under a non-symmetric external stress. 
     
     
         32 . The method of  claim 27 , further comprising changing the diameter of the haptic between about 0.4% and about 2.0%. 
     
     
         33 . The method of  claim 27 , wherein the placing step comprises molding the optic directly onto the haptic. 
     
     
         34 . The method of  claim 27 , wherein the placing step comprises attaching a pre-formed optic to the haptic. 
     
     
         35 . The method of  claim 27 , further comprising supporting the optic around an equator of the optic. 
     
     
         36 . The method of  claim 27 , further comprising producing an internal stress in the optic.