Patent Publication Number: US-2022226103-A1

Title: Intraocular lens having a haptic structure with a streamlined cross-sectional geometry

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. patent application Ser. No. 16/174,409, filed Oct. 30, 2018, which claims priority to and benefit of U.S. Provisional Patent Application No. 62/579,989, filed Nov. 1, 2017. The entire contents of each of these applications are incorporated by reference herein in their entirety. 
    
    
     FIELD 
     The present disclosure relates generally ophthalmic lenses and, more particularly, to intraocular lenses having a haptic structure with a streamlines cross-sectional geometry. 
     BACKGROUND 
     Intraocular lenses (IOLs) may be implanted in patients&#39; eyes to replace a patient&#39;s natural lens. An IOL typically includes (1) an optic that corrects the patient&#39;s vision (e.g., typically via refraction or diffraction), and (2) haptics that constitute support structures that hold the optic in place within the patient&#39;s eye (e.g., within capsular bag). In general, a physician selects an IOL for which the optic has the appropriate corrective characteristics for the patient. During ophthalmic surgery, often performed for conditions such as cataracts, the surgeon implants selected IOL by making an incision in the capsular bag of the patient&#39;s eye (a capsulorhexis) and inserting the IOL through the incision. Typically, the IOL is folded for insertion into the capsular bag via a corneal incision and unfolded once in place within the capsular bag. During unfolding, the haptics may expand such that a small section of each bears on the capsular bag, retaining the IOL in place. 
     In some cases, the IOL must be removed, or explanted. To explant an IOL, the IOL may be cut into small pieces and removed through an incision. The IOL may also be repositioned during the surgical procedure after the haptics have been expanded. In either explantation or repositioning of the IOL, the haptics are moved away from the capsular bag. However, because the haptics may adhere to the capsular bag, movement of the haptics may damage or tear the capsular bag. Such an injury to the patient is undesirable. 
     Even if the IOL remains in place, there may be shortcomings. IOLs may cause striae, or folds, in the posterior capsular bag. Striae in the capsular bag may result in posterior capsular opacification (PCO) by providing a mechanism for the growth and/or migration of cells. A mechanism for addressing PCO is thus desired. 
     Accordingly, what is needed is an improved IOL that may address PCO while allowing for repositioning and explantation of the IOL. 
     SUMMARY 
     In certain embodiments, an ophthalmic device includes an optic and a haptic structure coupled with the optic. The optic includes an optic axis. The haptic structure is coupled to the optic. The haptic structure retains the ophthalmic device within a capsular bag of a patient&#39;s eye. At least a portion of the haptic structure has a cross-section and a peripheral surface forming an outer periphery of a portion of the cross-section. At least a portion of the peripheral surface contacts the capsular bag and is smoothly curved. 
     In certain embodiment, the hatpic geometry described herein may provide one or more technical advantages. For example, IOLs having the haptic geometry described herein may be more easily explanted and/or repositioned as compared with existing IOLs. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present disclosure and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings in which like reference numerals indicate like features and wherein: 
         FIGS. 1A-1I  depict various views of an exemplary embodiment of an ophthalmic device having a haptic structure with a cross-section having a streamlined periphery; 
         FIGS. 2A-2B  depict another exemplary embodiment of a portion of an ophthalmic device having a haptic structure with a cross-section having a streamlined periphery; 
         FIGS. 3A-3B  depict another exemplary embodiment of a portion of an ophthalmic device having a haptic structure with a cross-section having a streamlined periphery; 
         FIGS. 4A-4B  depict another exemplary embodiment of a portion of an ophthalmic device having a haptic structure with a cross-section having a streamlined periphery; 
         FIG. 5  depicts another exemplary embodiment of a portion of an ophthalmic device having a haptic structure with a cross-section having a streamlined periphery; 
         FIG. 6  depicts another exemplary embodiment of a portion of an ophthalmic device having a haptic structure with a cross-section having a streamlined periphery; 
         FIG. 7  depicts another exemplary embodiment of a portion of an ophthalmic device having a haptic structure with a cross-section having a streamlined periphery; 
         FIG. 8  depicts another exemplary embodiment of a portion of an ophthalmic device having a haptic structure with a cross-section having a streamlined periphery; 
         FIG. 9  depicts another exemplary embodiment of a portion of an ophthalmic device having a haptic structure with a cross-section having a streamlined periphery; 
         FIG. 10  depicts another exemplary embodiment of a portion of an ophthalmic device having a haptic structure with a cross-section having a streamlined periphery; and 
         FIGS. 11A-11C  depict exemplary embodiments of textures/patterns that may be used on the haptic structure with a cross-section having a streamlined periphery. 
     
    
    
     The skilled person in the art will understand that the drawings, described below, are for illustration purposes only. The drawings are not intended to limit the scope of the applicant&#39;s disclosure in any way. 
     DETAILED DESCRIPTION 
     The exemplary embodiments relate to ophthalmic devices such as intraocular lenses (IOLs). The following description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the exemplary embodiments and the generic principles and features described herein will be readily apparent. Phrases such as “exemplary embodiment”, “one embodiment” and “another embodiment” may refer to the same or different embodiments as well as to multiple embodiments. The embodiments will be described with respect to systems and/or devices having certain components. However, the systems and/or devices may include more or less components than those shown, and variations in the arrangement and type of the components may be made without departing from the scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features described herein. 
     In general, the present disclosure relates to an ophthalmic device that includes an optic and a haptic structure coupled with the optic. The optic includes an optic axis. The haptic structure is coupled to the optic. The haptic structure retains the ophthalmic device within a capsular bag of a patient&#39;s eye. At least a portion of the haptic structure has a cross-section and a peripheral surface forming an outer periphery of a portion of the cross-section. At least a portion of the peripheral surface contacts the capsular bag and is smoothly curved. 
       FIGS. 1A-1G  depict various views of an exemplary embodiment of an ophthalmic device  100 A having a closed-loop haptic structure  120 A with a cross-section having a streamlined periphery. As discussed below, in other embodiments, an open-loop haptic structure may be used. For simplicity, the ophthalmic device  100 A is also referred to as an IOL  100 A. For clarity,  FIGS. 1A-1G  are not to scale and not all components may be shown. The IOL  100 A includes the haptic structure  120 A as well as an optic  110 .  FIGS. 1A and 1B  are plan and side views of the IOL  100 A.  FIG. 1C  is a cross-sectional view of a portion of the haptic structure  120 A.  FIG. 1D  is a cross-sectional view of the portion of the haptic structure  120 A when in use in a patient&#39;s eye.  FIG. 1  E is a plan view of the IOL  100 A when being manipulated.  FIG. 1F  is a cross-sectional view of a portion of the haptic structure  120 A when being manipulated.  FIG. 1G  depicts the forces involved in manipulating the haptic structure  120 A. 
     The optic  110  is an ophthalmic lens  110  that may be used to correct a patient&#39;s vision. For example, the optic may be a refractive and/or diffractive lens. The optic  110  may be a monofocal lens, a multifocal lens, a toric lens, accommodating or another, analogous lens. The anterior and/or posterior surface of the optic  110  may thus have features including but not limited to a base curvature and diffraction grating(s). The optic  110  may refract and/or diffract light to correct the patient&#39;s vision. The optic  110  has an optic axis  112  that is out of the plane of the page in  FIG. 1A . The optic  110  is depicted as having a circular footprint in the plan view of  FIG. 1A . In other embodiments, the optic  110  may have a differently shaped footprint. In some embodiments, the optic  110  may also include other features that are not shown for clarity. The optic  110  may be formed of one or more of a variety of flexible optical materials. For example, the optic  110  may include but is not limited to one or more of silicone, a hydrogel and an acrylic such as AcrySof®. 
     The haptic structure  120 A is a support structure used to hold the ophthalmic device  100 A in place in the capsular bag of a patient&#39;s eye (not explicitly shown in  FIGS. 1A-1C and 1E ). A portion of the capsular bag  130 A is shown in  FIG. 1D . The haptic structure  120 A includes closed loops  122 A- 1  and  122 A- 2  (collectively  122 ) and inner ring or frame  124 A. The inner portion of the frame  124 A is desired to match the shape of the optic  110 . In other embodiments, the frame  124 A may be omitted. In some embodiments, the haptic structure  120 A and the optic  110  may be molded together. Thus, the optic  110  and haptic  120 A may form a single monolithic structure. In other embodiments, the haptic structure  120 A may be otherwise attached to the optic  110 . For example, the haptic structure  120 A may be bonded to or molded around a preexisting optic  110 . 
     The loops  122 A retain the IOL  100 A in position in the patient&#39;s eye by bearing upon the capsular bag  130 A. Each of the loops  122 A subtends a large angle. Consequently, the loops  122 A contact the capsular bag over a significantly larger angle than for haptics having open loops. As a result, stability may be enhanced and formation of striae reduced. Although two closed loops  122 A are shown, another number of loops may be used. The shape of the closed loops  122 A may differ. Further, open loops rather than closed loops may be used in other embodiments. For example,  FIGS. 1  H and  11  depict IOLs  100 A′ and  100 A″ analogous to the IOL  100 A.  FIG. 1  H depicts an IOL  100 A′ having C-shaped open loops  122 A- 1 ′ and  122 A- 2 ′ (collectively loops  122 A′).  FIG. 11  depicts an IOL  100 A″ having L-shaped open loops  122 A- 1 ″ and  122 A- 2 ″. Thus, the IOLs  100 A′ and  100 A″ may be the same as the IOL  100 A except that the loops  122 A′ and  122 A″ are open. For example, the cross-section of the open loops  122 A′ and  122 A″ may be the same as the cross section for closed loops  122 A. 
       FIGS. 1C and 1D  depict the cross-section of the closed loops  122 A, for example at the line A-A shown in  FIG. 1A . Although a specific location for the cross-section is shown in  FIG. 1A , in other embodiments, the cross-section may be the same at another portion of the closed loop  122 A- 1  and/or for at least part of the other closed loop  122 A- 2 . The cross-section shown in  FIGS. 1C-1D  is for at least part of the loop(s)  122 A that bear on the capsular bag. In some embodiments, the entirety of each loop  122 A has the cross-section shown. In other embodiments, the portion of a loop  122 A that does not bear on the capsular bag  130 A, for example near the frame  124 A, may have a different cross-section. 
     The cross-section for the loop(s)  122 A has an inner peripheral surface  126 A and an outer peripheral surface  128 A. The outer peripheral surface  128 A is at the outside of the loops  122 A and may bear on the capsular bag  130 A, as shown in  FIG. 1D . The outer peripheral surface  128 A exerts a force on the capsular bag  130 A. Thus, the outer peripheral surface may aid in expanding the capsular bag  130 A and stabilizing the IOL  100 A within the capsular bag  130 A. The inner peripheral surface  126 A is opposite to the outer peripheral surface  128 A and forms the inside of the loops  122 A. Thus, at least part of the inner peripheral surface  126 A may not contact the capsular bag or may exert significantly less force on the capsular bag. If arms rather than loops are present in the haptic structure  120 A, then the inner peripheral surface forms the portion of the cross-section that does not bear on the capsular bag. 
     The particular shape of the cross-section may differ in different embodiments even when the general shape does not change. For example, the length between the corner  129 A of the inner peripheral surface  126 A and outer peripheral surface  128 A and the thickness between the posterior and anterior surfaces, may differ in different embodiments. in some embodiments, the thickness may be on the order of 0.5 mm. In some such embodiments, the length may be approximately 0.9 mm. In other such embodiments, the length may be approximately 0.7 mm. Thus, the cross section of the haptic  120 A may have a different appearance for different aspect ratios. 
     At least part of the outer peripheral surface  128 A is smoothly curved. In the embodiment shown, the entire peripheral surface  128 A is curved. Stated differently, the geometry for the outer peripheral surface  128 A of the cross-section is streamlined. Thus, on a macro-scale, the outer peripheral surface  128 A has a continuous and well-defined slope. In the embodiment shown in  FIGS. 1A-1D , no additional textures or features are present on the outer peripheral surface. Textures may have a characteristic length on the order of nanometers to microns or less. Features may have a characteristic length on the order of tens of microns. In other embodiments, such textures or features may be present. However, on the scale of the diameter or height of the cross-section, the outer peripheral surface  128 A is smoothly curved. Because of its curved shape, the outer peripheral surface  128 A may have a greater contact with the capsular bag  130 A. This is shown in  FIG. 1  D. As a result, the haptic  120 A may be better able to stabilize the IOL  100 A. In addition, the curvature of and lack of sharp corners in the outer peripheral surface  128 A may make the loops  122 A less likely to adhere to and tear the capsular bag  130 A in the event of explantation or repositioning. 
     For example,  FIGS. 1E and 1F  depict the IOL  100 A and haptic  120 A when being repositioned or explanted using a manipulation force, Fman.  FIG. 1G  depicts a plan view of the forces involved in repositioning or explanting the IOL  100 A. The manipulation force, Fman, is used in moving the haptic away from the capsular bag  130 A. In response to the manipulation force, the loop  122 A- 1  is deformed as shown in  FIG. 1E . More specifically, the portion of the loop  122 A- 1  to which the manipulation force is applied moves in the direction of the force: toward the optic  110 . The reaction forces, Freaction  1  and Freaction  2 , due to the manipulation force are along the loop  122 A- 1  and in the opposite direction to the manipulation fore. Thus, as can be seen in  FIG. 1G , the reaction forces tend to separate the loop  122 A- 1  from the capsular bag. In addition, the loop  122 A- 1  also undergoes a torque, τ. This torque also tends to separate the loop  122 A- 1  from the capsular bag  130 A. Consequently, the configuration of the cross-section of the loops  122 A tend to improve the mobility of the loop  122 A with respect to the capsular bag  130 A when the loop  122 A is being manipulated. 
     In contrast to the outer peripheral surface  128 A, the inner peripheral surface may not be smoothly curved. In the embodiment shown, the inner peripheral surface  126 A has a sharp corner  129 A. On a macro-scale the slope of the inner peripheral surface  126 A is not well-defined at the corner  129 A and is not continuous on either side of the corner  129 A. Thus, the cross-section for the haptic structure  120 A is teardrop shaped. Because of the presence of the sharp corner  129 A, the optic  110  may be surrounded on all sides by sharp edges. These sharp edges may also reduce the probability of cells migrating to the optic  110  from any side. PCO may be reduced or eliminated. 
     The frame  124 A may also have sharp outside corners (at the outer surface of the frame  124 A). The optic  110  might have sharp corners (not shown). As a result, the optic  110  may be surrounded on all sides by sharp edges. These sharp edges may also reduce the probability of cells migrating to the optic  110  from any side. PCO may be reduced or eliminated. 
     The IOL  100 A may improve patient outcomes. The streamlined outer peripheral surface  128 A of the cross-section of the loops  122 A may reduce adherence of the loops  122 A to the capsular bag  130 A during explantation and/or repositioning. Thus, damage to the patient&#39;s eye due to manipulation of the haptic  120 A may be reduced. The smooth curve for the outer peripheral surface  128 A may also allow for improved stability of the IOL  100 A when the IOL  100 A is in place. Sharp edges such as the edge  129 A for the haptic structure  120 A may further reduce PCO. Thus, performance of the IOL  100 A may be improved. 
       FIGS. 2A and 2B  depict another exemplary embodiment of a haptic structure  120 B for an ophthalmic device such as an IOL. For clarity,  FIGS. 2A and 2B  are not to scale and not all components may be shown.  FIG. 2A  depicts a cross-section of the haptic structure  120 B.  FIG. 2B  depicts the cross-section of the haptic structure  120 B when in use, bearing upon the capsular bag  130 B of a patient&#39;s eye. The haptic  120 B and IOL of which it is a part are analogous to the haptic  120 A and IOL  100 A. Consequently, analogous components have similar labels. Thus, the IOL would include an optic (not explicitly shown) and the haptic structure  120 B (of which only the cross-section is shown) that are analogous to the optic  110  and the haptic structure  120 A. In some embodiments, the haptic structure  120 B is a closed-loop haptic structure having loops analogous to the loops  122 A and optionally including a frame analogous to the frame  124 A. The frame may be omitted, loop(s) of another size and/or another number of loops may be used. In other embodiments, the haptic structure  120 B may have one or more open loops. 
     The haptic structure  120 B functions in an analogous manner to and shares analogous benefits with the haptic structure  120 A. The haptic structure  120 B thus includes an outer peripheral surface  128 B and an inner peripheral surface  126 B that are analogous to surfaces  128 A and  126 A, respectively. However, the shape of the cross-section is different. The entire peripheral surface  128 B is smoothly curved. Thus, on a macro-scale, the outer peripheral surface  128 B has a continuous and well-defined slope. In the embodiment shown in  FIGS. 2A-2B , no additional textures or features are present on the outer peripheral surface  128 B. In another embodiment, textures, features, and/or a coating may be present on the IOL  100 B. Because of its curved shape, the outer peripheral surface  128 B may have a greater contact with the capsular bag  130 B as shown in  FIG. 2B . As a result, the haptic  120 A may be better able to stabilize the IOL  100 A. In addition, the curvature of and lack of sharp corners in the outer peripheral surface  128 B may make the loops less likely to adhere to and tear the capsular bag  130 A in the event of explantation or repositioning. 
     Instead of having a teardrop shape, most of the peripheral surface  126 B is flat. Thus, the inner peripheral surface  126 B includes a straight side and two sharp corners  129 B- 1  and  129 B- 2 . On a macro-scale the slope of the inner peripheral surface  126 B is not well-defined at the corners  129 B- 1  and  129 B- 2  and is not continuous on either side of the corners  129 B- 1  and  129 B- 2 . Because of the presence of the sharp corners  129 B- 1  and  129 B- 2 , the optic (not shown) may be surrounded by sharp edges on the posterior side to reduce or prevent PCO. The optic may also have a curved edge profile for glare reduction. The haptic cross-sectional edge profile may be blended and smoothly transitioned to the optic edge profile. 
     The haptic structure  120 B may improve patient outcomes. The streamlined outer peripheral surface  128 B of the cross-section may reduce adherence of the haptic structure  120 B to the capsular bag  130 B during explantation and/or repositioning. Thus, damage to the patient&#39;s eye due to manipulation of the haptic  120 B may be reduced. The smooth curve for the outer peripheral surface  128 B may also allow for improved stability of the IOL when the IOL is in place. Sharp edges such as the edges  129 B- 1  for the haptic structure  120 B may further reduce PCO. Thus, performance of the IOL may be improved. 
       FIGS. 3A and 3B  depict another exemplary embodiment of a haptic structure  120 C for an ophthalmic device such as an IOL. For clarity,  FIGS. 3A and 3B  are not to scale and not all components may be shown.  FIG. 3A  depicts a cross-section of the haptic structure  120 C.  FIG. 3B  depicts the cross-section of the haptic structure  120 C when in use, bearing upon the capsular bag  130 C of a patient&#39;s eye. The haptic  120 C and IOL of which it is a part are analogous to the haptic(s)  120 A and/or  120 B. Consequently, analogous components have similar labels. Thus, the IOL would include an optic (not explicitly shown) and the haptic structure  120 C that are analogous to the optic  110  and haptic structure  120 A and/or  120 B. In some embodiments, the haptic structure  120 B is a closed-loop haptic structure having loops analogous to the loops  122 A and optionally including a frame analogous to the frame  124 A. The frame may be omitted, loop(s) of another size and/or another number of loops may be used. In other embodiments, the haptic structure  120 C may have one or more open loops. 
     The haptic structure  120 C functions in an analogous manner to and shares analogous benefits with the haptic structure(s)  120 A and/or  120 B. The haptic structure  120 C thus includes an outer peripheral surface  128 C and an inner peripheral surface  126 C that are analogous to surfaces  128 A/ 128 B and  126 A/ 126 B, respectively. However, the shape of the cross-section is different. The entire outer peripheral surface  128 B and inner peripheral surface  126 C are smoothly curved. 
     In the embodiment shown in  FIGS. 3A-3B , an additional texture or feature  129 C is present on the posterior of the outer peripheral surface  128 C. Whether the component  129 C is a texture or feature depends upon its characteristic size, discussed above. This texture is shown as a step pattern. However, other patterns are possible. For example, a repeated wavy surface, repeated lines, or other texture or feature may be present. In another embodiment, the feature  129 C may simply be a roughening of the surface. In some embodiments, textures, features, and/or a coating may be present on the IOL to help reduce PCO. Because of its curved shape, the outer peripheral surface  128 C may have a greater contact with the capsular bag  130 C. As a result, the haptic  120 C may be better able to stabilize the IOL. In addition, the curvature of and lack of sharp corners in the outer peripheral surface  128 AC may make the loops  122 AC less likely to adhere to or tear the capsular bag  130 A in the event of explantation or repositioning. 
     The haptic structure  120 C may have enhanced performance. The streamlined outer peripheral surface  128 C of the cross-section may reduce adherence of the haptic structure  120 C to the capsular bag  130 C during explantation and/or repositioning. Thus, damage to the patient&#39;s eye due to manipulation of the haptic  120 C may be reduced. The smooth curve for the outer peripheral surface  128 C may also allow for improved stability of the IOL when the IOL is in place. The texture/feature  129 C for the haptic structure  120 BC may further reduce PCO. Thus, performance of the IOL may be improved. 
       FIGS. 4A and 4B  depict another exemplary embodiment of a haptic structure  120 D for an ophthalmic device such as an IOL. For clarity,  FIGS. 4A and 4B  are not to scale and not all components may be shown.  FIG. 4A  depicts a cross-section of the haptic structure  120 D.  FIG. 4B  depicts the cross-section of the haptic structure  120 D when in use, bearing upon the capsular bag  130 D of a patient&#39;s eye. The haptic  120 D and IOL of which it is a part are analogous to the haptic(s)  120 A,  120 B and/or  120 C. Consequently, analogous components have similar labels. Thus, the IOL would include an optic (not explicitly shown) and the haptic structure  120 D that are analogous to the optic  110  and haptic structure  120 A,  120 B and/or  120 C. In some embodiments, the haptic structure  120 C is a closed-loop haptic structure having loops analogous to the loops  122 A,  122 B and/or  120 C and optionally including a frame analogous to the frame  124 A. The frame may be omitted, loop(s) of another size and/or another number of loops may be used. In other embodiments, the haptic structure  120   b  may have one or more open loops. 
     The haptic structure  120 D functions in an analogous manner to and shares analogous benefits with the haptic structure(s)  120 A,  120 B and/or  120 C. The haptic structure  120 D thus includes an outer peripheral surface  128 D and an inner peripheral surface  126 C that are analogous to surfaces  128 A/ 128 B/ 128 C and  126 A/ 126 B/ 126 C, respectively. The cross-section of the haptic structure  120 D is most analogous to the haptic structure  120 C. Instead of having the long axis vertical as in  FIGS. 3A and 3B , the long axis is horizontal in  FIGS. 4A-4B . 
     In addition, the haptic structure  120 D has a coating  127 D. Although shown as residing on only part of the surface of the haptic structure  120 D, the coating  127 D may cover the entire peripheral surface  128 D and  126 D. The coating  127 D may limit the adherence of the outer peripheral surface  128 D to the capsular bag  130 D. Thus, the coating  127 D may facilitate manipulation or explantation. For example, the coating  127 D may include but is not limited to one or more of polyethylene glycol (PEG), plasma and parylene. 
     The haptic structure  120 D may improve performance of an IOL. The streamlined outer peripheral surface  128 B of the cross-section may reduce adherence of the haptic structure  120 D to the capsular bag  130 D during explantation and/or repositioning. The coating  127 D may also facilitation repositioning and/or explantation. Thus, damage to the patient&#39;s eye due to manipulation of the haptic  120 D may be reduced. The smooth curve for the outer peripheral surface  128 D may also allow for improved stability of the IOL when the IOL is in place. The texture/feature  127 D for the haptic structure  120 D may further reduce PCO. Thus, performance of the IOL may be improved. 
       FIG. 5  depicts a cross-section of another exemplary embodiment of a haptic structure  120 E for an ophthalmic device such as an IOL. For clarity,  FIG. 5  is not to scale and not all components may be shown. The haptic  120 E and IOL of which it is a part are analogous to the haptic(s)  120 A,  120 B,  120 C and/or  120 D. Consequently, analogous components have similar labels. Thus, the IOL would include an optic (not explicitly shown) and the haptic structure  120 E that are analogous to the optic  110  and haptic structure  120 A,  120 B,  120 C and/or  120 D. In some embodiments, the haptic structure  120 E is a closed-loop haptic structure having loops analogous to the loops  122 A and optionally including a frame analogous to the frame  124 A. The frame may be omitted, loop(s) of another size and/or another number of loops may be used. In other embodiments, the haptic structure  120 E may have one or more open loops. 
     The haptic structure  120 E includes an outer peripheral surface  128 E and an inner peripheral surface  126 E that are analogous to surfaces  128 A,  128 B,  128 C, and  128 D and  126 A,  126 B,  126 C and  126 D, respectively. However, the shape of the cross-section is different. The cross-section is generally rectangular but has rounded corners and rounded sides. Although all corners are shown as rounded, in some embodiments, one or both corners for the inner peripheral surface  126 E may be sharp to mitigate PCO. 
     The haptic structure  120 E may improve patient outcomes. The streamlined outer peripheral surface  128 E of the cross-section may reduce adherence of the haptic structure  120 E to the capsular bag during explantation and/or repositioning. Thus, damage to the patient&#39;s eye due to manipulation of the haptic  120 E may be reduced. The smooth curve for the outer peripheral surface  128 E may also allow for improved stability of the IOL when the IOL is in place. 
       FIG. 6  depicts a cross-section of another exemplary embodiment of a haptic structure  120 F for an ophthalmic device such as an IOL. For clarity,  FIG. 6  is not to scale and not all components may be shown. The haptic  120 F and IOL of which it is a part are analogous to the haptic(s)  120 A,  120 B,  120 C,  120 D and/or  120 E. Consequently, analogous components have similar labels. Thus, the IOL would include an optic (not explicitly shown) and the haptic structure  120 F that are analogous to the optic  110  and haptic structure  120 A,  120 B,  120 C,  120 D and/or  120 E. In some embodiments, the haptic structure  120 F is a closed-loop haptic structure having loops analogous to the loops  122 A and optionally including a frame analogous to the frame  124 A. The frame may be omitted, loop(s) of another size and/or another number of loops may be used. In other embodiments, the haptic structure  120 F may have one or more open loops. 
     The haptic structure  120 F includes an outer peripheral surface  128 F and an inner peripheral surface  126 F that are analogous to outer surfaces  128 A,  1288 ,  128 C,  128 D and  128 E and inner surfaces  126 A,  126 B,  126 C,  126 D and  126 E, respectively. However, the shape of the cross-section is different. The cross-section is generally rectangular with flat sides but has rounded corners. Although all corners are shown as rounded, in some embodiments, one or both corners for the inner peripheral surface  126 F may be sharp to mitigate PCO. The haptic structure  120 F also has a coating  129 F. Although shown as residing on only part of the surface of the haptic structure  120 F, the coating  129 F may cover a larger or different area including the entire peripheral surfaces  128 F and  126 F. The coating  129 F may reduce PCO. For example, the coating  129 F may include but is not limited to one or more of PEG and Erufosine. 
     The streamlined outer peripheral surface  128 F of the cross-section may reduce adherence of the haptic structure  120 F to the capsular bag during explantation and/or repositioning. Thus, damage to the patient&#39;s eye due to manipulation of the haptic  120 F may be reduced. The smooth curve for the outer peripheral surface  128 F may also allow for improved stability of the IOL when the IOL is in place. The coating  129 F for the haptic structure  120 F may also reduce PCO. Thus, performance of the IOL may be improved. 
       FIG. 7  depicts a cross-section of another exemplary embodiment of a haptic structure  120 G for an ophthalmic device such as an IOL. For clarity,  FIG. 7  is not to scale and not all components may be shown. The haptic  120 G and IOL of which it is a part are analogous to the haptic(s)  120 A,  120 B,  120 C,  120 D,  120 E and/or  120 F. Consequently, analogous components have similar labels. Thus, the IOL would include an optic (not explicitly shown) and the haptic structure  120 G that are analogous to the optic  110  and haptic structure  120 A,  120 B,  120 C,  120 D,  120 E and/or  120 F. In some embodiments, the haptic structure  120 G is a closed-loop haptic structure having loops analogous to the loops  122 A and optionally including a frame analogous to the frame  124 A. The frame may be omitted, loop(s) of another size and/or another number of loops may be used. In other embodiments, the haptic structure  120 G may have one or more open loops. 
     The haptic structure  120 G includes an outer peripheral surface  128 G and an inner peripheral surface  126 G that are analogous to outer surfaces  128 A,  128 B,  128 C,  128 D,  128 E and  128 F and inner surfaces  126 A,  126 B,  126 C,  126 D,  126 E and  126 F, respectively. However, the shape of the cross-section is different. The cross-section is merely an organic shape having smoothly curved peripheral surfaces  128 G and  126 G. In addition, the cross-section includes a sharp corner  129 G for reducing PCO. 
     The streamlined outer peripheral surface  128 G of the cross-section may reduce adherence of the haptic structure  120 G to the capsular bag during explantation and/or repositioning. Thus, damage to the patient&#39;s eye due to manipulation of the haptic  120 G may be reduced. The smooth curve for the outer peripheral surface  128 G may also allow for improved stability of the IOL when the IOL is in place. The coating  129 G for the haptic structure  120 G may also reduce PCO. Thus, performance of the IOL may be improved. 
       FIG. 8  depicts a cross-section of another exemplary embodiment of a haptic structure  120 H for an ophthalmic device such as an IOL. For clarity,  FIG. 8  is not to scale and not all components may be shown. The haptic  120 H and IOL of which it is a part are analogous to the haptic(s)  120 A,  120 B,  120 C,  120 D,  120 E,  120 F and/or  120 G. Consequently, analogous components have similar labels. Thus, the IOL would include an optic (not explicitly shown) and the haptic structure  120 H that are analogous to the optic  110  and haptic structure  120 A,  120 B,  120 C,  120 D,  120 E,  120 F and/or  120 G. In some embodiments, the haptic structure  120 H is a closed-loop haptic structure having loops analogous to the loops  122 A and optionally including a frame analogous to the frame  124 A. The frame may be omitted, loop(s) of another size and/or another number of loops may be used. In other embodiments, the haptic structure  120 H may have one or more open loops. 
     The haptic structure  120 H includes an outer peripheral surface  128 H and an inner peripheral surface  126 H that are analogous to outer surfaces  128 A,  128 B,  128 C,  128 D,  128 E,  128 F and  128 G and inner surfaces  126 A,  126 B,  126 C,  126 D,  126 E,  126 F and  126 G, respectively. However, the shape of the cross-section is different. The cross-section is a tear drop shape analogous to that of the haptic structure  120 A. However, the corner  129 A has been rounded. Although the sides of the inner peripheral surface  126 H are shown as rounded (i.e. convex), in other embodiments, the sides might be flat or concave. 
     The haptic structure  120 H also includes a texture or features  129 H- 1  and a coating  129 H- 2  on the texture/feature  129 H- 1 . The texture/feature  129 H- 1  may be analogous to the texture/feature  129 C. The coating  129 H- 2  may be analogous to the coating  127 D or  129 F. Thus, the coating  129 H- 2  may reduce PCO. The coating  129 H- 2  might be used to facilitate explantation or manipulation of the haptic structure  120 H. 
     The streamlined outer peripheral surface  128 H of the cross-section may reduce adherence of the haptic structure  120 H to the capsular bag during explantation and/or repositioning. Thus, damage to the patient&#39;s eye due to manipulation of the haptic  120 H may be reduced. The smooth curve for the outer peripheral surface  128 H may also allow for improved stability of the IOL when the IOL is in place. The texture/feature  129 H- 1  may mitigate PCO. The coating  129 H- 2  for the haptic structure  120 H may also reduce PCO or may facilitate explantation or repositioning. Thus, performance of the IOL may be improved. 
       FIG. 9  depicts a cross-section of another exemplary embodiment of a haptic structure  120 J for an ophthalmic device such as an IOL. For clarity,  FIG. 9  is not to scale and not all components may be shown. The haptic  120 J and IOL of which it is a part are analogous to the haptic(s)  120 A,  120 B,  120 C,  120 D,  120 E,  120 F,  120 G and/or  120 H. Consequently, analogous components have similar labels. Thus, the IOL would include an optic (not explicitly shown) and the haptic structure  120 J that are analogous to the optic  110  and haptic structure  120 A,  120 B,  120 C,  120 D,  120 E,  120 F,  120 G and/or  120 H. In some embodiments, the haptic structure  120 J is a closed-loop haptic structure having loops analogous to the loops  122 A and optionally including a frame analogous to the frame  124 A. The frame may be omitted, loop(s) of another size and/or another number of loops may be used. In other embodiments, the haptic structure  120 J may have one or more open loops. 
     The haptic structure  120 J includes an outer peripheral surface  128 J and an inner peripheral surface  126 J that are analogous to outer surfaces  128 A,  1288 ,  128 C,  128 D,  128 E,  128 F,  128 G and  128 H and inner surfaces  126 A,  126 B,  126 C,  126 D,  126 E,  126 F,  126 G and  126 H, respectively. However, the shape of the cross-section is different. The cross-section is generally a tear drop shape analogous to that of the haptic structures  120 A and  120 H. The corner  129 A has been rounded. In addition, the sides of inner peripheral surface  126 J are concave rather than straight or convex. 
     The haptic structure  120 J also includes a texture or features  129 J- 1  and a coating  129 J- 2 . The texture/feature  129 J- 1  may be analogous to the texture/feature(s)  129 C and  129 H- 1 . The texture/feature  129 J- 1  may thus mitigate PCO. The coating  129 J- 2  may be analogous to the coating  127 D or  129 F. The coating  129 J- 2  is also located on the anterior side. The coating  129 J- 2  may reduce PCO and/or reduce adherence of the haptic structure  120 J to the capsular bag when the haptic structure  120 J is being manipulated. 
     The smooth curve of the outer peripheral surface  128 J of the cross-section may reduce adherence of the haptic structure  120 J to the capsular bag during explantation and/or repositioning. Thus, damage to the patient&#39;s eye due to manipulation of the haptic  120 J may be reduced. The smooth curve for the outer peripheral surface  128 J may also allow for improved stability of the IOL when the IOL is in place. The texture/feature  129 J- 1  may mitigate PCO. The coating  129 J- 2  for the haptic structure  120 J may also reduce PCO or may facilitate explantation or repositioning. Thus, performance of the IOL may be improved. 
       FIG. 10  depicts a cross-section of another exemplary embodiment of a haptic structure  120 k for an ophthalmic device such as an IOL. For clarity,  FIG. 10  is not to scale and not all components may be shown. The haptic  120 k and IOL of which it is a part are analogous to the haptic(s)  120 A,  120 B,  120 C,  120 D,  120 E,  120 F,  120 G,  120 H and/or  120 J. Consequently, analogous components have similar labels. Thus, the IOL would include an optic (not explicitly shown) and the haptic structure  120 K that are analogous to the optic  110  and haptic structure  120 A,  120 B,  120 C,  120 D,  120 E,  120 F,  120 G,  120 H and/or  120 J. In some embodiments, the haptic structure  120 K is a closed-loop haptic structure having loops analogous to the loops  122 A and optionally including a frame analogous to the frame  124 A. The frame may be omitted, loop(s) of another size and/or another number of loops may be used. In other embodiments, the haptic structure  120 K may have one or more open loops. 
     The haptic structure  120 K includes an outer peripheral surface  128 K and an inner peripheral surface  126 K that are analogous to outer surfaces  128 A,  128 B,  128 C,  128 D,  128 E,  128 F,  128 G,  128 H and  128 J and inner surfaces  126 A,  126 B,  126 C,  126 D,  126 E,  126 F,  126 G,  126 H and  126 J, respectively. The cross-section of the haptic  120 K matches that of the haptic structure  120 J. The haptic structure  120 K also includes a texture/features  129 K- 1  and a coating  129 K- 2  that are analogous to the texture/features  129 J- 1  and  129 J- 2 , respectively. However, the coating  129 K- 2  is also located on the posterior side away from the texture/feature  129 K- 1 . 
     The smooth curve of the outer peripheral surface  128 K of the cross-section may reduce adherence of the haptic structure  120 K to the capsular bag during explantation and/or repositioning. Thus, damage to the patient&#39;s eye due to manipulation of the haptic  120 K may be reduced. The smooth curve for the outer peripheral surface  128 K may also allow for improved stability of the IOL when the IOL is in place. The texture/feature  129 K- 1  may mitigate PCO. The coating  129 K- 2  for the haptic structure  120 K may also reduce PCO or may facilitate explantation or repositioning. Thus, performance of the IOL may be improved. 
     Various features of the haptic structures  120 A,  120 B,  120 C,  120 D,  120 E,  120 F,  120 G,  120 H,  120 J and  100 K have been described herein. One of ordinary skill in the art will recognize that one or more of these features may be combined in manners not explicitly disclosed herein and that are not inconsistent with the method and apparatus described. Further, as discussed above, the dimensions and/or aspect ratios of each embodiment may vary. Thus, the appearance of the cross-section may differ in different embodiments. In addition, individual features of different embodiments may be combined. For example, different quadrants shown in the cross-sections of different embodiments may be combined to form a new embodiment. Further, there is no requirement that the cross-section exhibit symmetry, such as symmetry around a horizontal axis, a vertical axis and/or an oblique axis. 
       FIGS. 11A, 11B and 11C  depict various embodiments of textures and/or features that might be used for one or more of the textures/features  129 C,  129 H- 1 ,  129 J- 1  and  129 K- 1 .  FIG. 11A  depicts textures/features  140 A having height h- 1 .  FIG. 11B  depicts textures/features  140 B having height h- 2 .  FIG. 11C  depicts textures/features  140 C having height h- 3 . The textures/features  140 A have a square profile and might be seen as a series of lines. Textures/features  140 B are a saw tooth having characteristic height h- 2 . Textures/features  140 C may be viewed as lines or steps but have curved edges. For heights h- 1 , h- 2  and h- 3  not larger than the order of nanometers to microns, items  140 A,  140 B and  140 C may be considered textures. For heights h- 1 , h- 2  and h- 3  on the order of tens of microns or more, items  140 A,  140 B and  140 C are features. However, the heights h- 1 , h- 2  and h- 3  are significantly less than the radius of curvature of the cross section of the haptics. Further, although specific patterns and constant heights are shown in  FIGS. 11A-11C , the textures/features  140 A,  140 B and  140 C may have varying height(s), width(s) and/or pitch(es). Further, at the smaller scales, the textures/features  140 A,  140 B and/or  140 C may simply be viewed as a roughening of the surface of the haptic. For the scales described above the textures/features  140 A,  140 B and  140 C may aid in reducing PCO. 
     It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different devices or applications. It will also be appreciated that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which alternatives, variations and improvements are also intended to be encompassed by the following claims.