Intraocular lenses

#The present invention relates to intraocular lenses (IOLs) and a method for making and using the same. More particularly, the present invention relates to accommodating IOLs designed for refractive correction in aphakic eyes where a diseased natural lens is surgically removed, such as in the case of cataracts.

#IOL implants have been used for many years in aphakic eyes as replacements for diseased natural crystalline lenses that have been surgically removed from the eyes. Many different IOL designs have been developed over past years and proven successful for use in aphakic eyes. Successful IOL designs to date primarily include an optic portion with supports therefor, called haptics, connected to and surrounding at least part of the optic portion. The haptic portions of an IOL are designed to support the optic portion of the IOL in the lens capsule, anterior chamber or posterior chamber of an eye.

#Commercially successful IOLs have been made from a variety of biocompatible materials, ranging from more rigid materials such as polymethylmethacrylate (PMMA) to softer, more flexible materials capable of being folded or compressed such as silicones, certain acrylics, and hydrogels. Haptic portions of the IOLs have been formed separately from the optic portion and later connected thereto through processes such as heat, physical staking and/or chemical bonding. Haptics have also been formed as an integral part of the optic portion in what is commonly referred to as “single-piece” IOLs.

#FIG. 1 is a schematic representation of the interior of a human eye;

#FIG. 2 is a plan view of an IOL with three haptics made in accordance with the present invention;

#FIG. 3 is a side view of the IOL of FIG. 2;

#FIG. 1 illustrates a simplified diagram of an eye 10 showing landmark structures relevant to the implantation of an intraocular lens of the present invention. Eye 10 includes an optically clear cornea 12 and an iris 14. A natural crystalline lens 16 and a retina 18 are located behind the iris 14 of eye 10. Eye 10 also includes anterior chamber 20 located in front of iris 14 and a posterior chamber 22 located between iris 14 and natural lens 16. Accommodating IOLs of the present invention are preferably implanted in lens capsule 24 after the removal of diseased natural lens 16 (aphakic application). When used in aphakic eyes, IOLs serve as replacements for surgically removed diseased natural lenses 16, such as for example following cataract surgeries. Eye 10 also includes an optical axis OA—OA that is an imaginary line that passes through the optical center 26 of anterior surface 28 and posterior surface 30 of lens 16. Optical axis OA—OA in the human eye 10 is generally perpendicular to a portion of cornea 12, natural lens 16 and retina 18.

#The IOL of the present invention, as illustrated in FIGS. 2 through 12 but best illustrated in FIGS. 2, 9 and 11, is identified generally by reference numeral 32. IOL 32 has an optic portion 34 with an outer peripheral edge 36. IOL 32 is designed for implantation preferably in lens capsule 24 of a patient's eye 10 and is preferably vaulted. A vault of approximately 1.0 to 2.0 mm but preferably 1.6 to 1.7 mm measuring from the plane of outer peripheral edge 36 of optic portion 34 to the plane of contact plates 38, described in detail below, is generally suitable. Preferably integrally formed on peripheral edge 36 of optic portion 34 are two, three or four looped or non-looped haptic elements 40, each having an edge portion 42. Haptic elements 40 are preferably integrally formed with and permanently connected to outer peripheral edge 36 of optic portion 34 by attachment portions 44. Alternatively however, haptic elements 40 may be attached to optic portion 34 by staking, chemical polymerization or other methods known to those skilled in the art. Each haptic element 40 also includes a broadened contact plate 38 designed to preferably engage inner surfaces 50 in lens capsule 24 of eye 10.

#In accordance with the present invention, haptic elements 40 are designed so that when IOL 32 is implanted in a patient's eye 10 and held in place through compressive forces exerted by inner surfaces 50 on contact plates 38 of haptic elements 40, haptic elements 40 flex so that contact plates 38 do not slide along surfaces 50 in eye 10. Accordingly, haptic elements 40 are designed to flex in a plane generally perpendicular to that of optic portion 34 of IOL 32 and generally parallel to that of optical axis OA—OA of eye 10. By designing this type of flexibility characteristic into haptic elements 40, IOL 32 allows an eye to achieve multifocal visual imaging without the aid of eyeglasses. The flexibility characteristic of haptic elements 40 maximizes axial displacement of optic portion 34 in a direction along optical axis OA—OA of eye 10. Compressive forces of differing magnitudes within the range of approximately 0.1 to 5 mN exerted against contact plates 38 of haptic elements 40 to effect approximately an overall 1.0 mm in diameter compression of IOL 32, such as that caused by natural brain-induced forces within eye 10, results in more than approximately 1.0 mm, but more preferably more than approximately 1.5 mm and most preferably more than approximately 2.0 mm axial displacement of optic portion 34 along optical axis OA—OA in an eye 10. The unique design of IOL 32 achieves significantly maximized axial displacement of optic portion 34. The IOL 32 of the present invention with its maximized axial displacement of optic portion 34 enables an eye to achieve multifocal visual imaging when a wide range of compressive forces, potentially even greater than those described above, are applied to eye 10.