Accommodating intraocular lens
An accommodating intraocular lens to be implanted within the natural capsular bag of a human eye from which the natural lens matrix has been removed through an anterior capsule opening in the bag circumferentially surrounded by an anterior capsular remnant. During a postoperative healing period following surgery, the anterior capsular remnant fuses to the posterior capsule of the bag by fibrosis about haptics on the implanted lens while the ciliary muscle is maintained in its relaxed state by a cycloplegic to prevent dislocation of the lens, and the lens is deflected rearwardly by the fibrosing anterior capsular remnant to a distant vision position against the elastic posterior capsule of the bag in which the posterior capsule is stretched rearwardly. After fibrosis is complete, natural brain-induced contraction and relaxation of the ciliary muscle relaxes and stretches the fibrosed anterior remnant and increases and reduces vitreous pressure in the eye to effect vision accommodation by the remnant, the posterior capsule, and vitreous pressure.
Latest Patents:
- PHARMACEUTICAL COMPOSITIONS OF AMORPHOUS SOLID DISPERSIONS AND METHODS OF PREPARATION THEREOF
- AEROPONICS CONTAINER AND AEROPONICS SYSTEM
- DISPLAY SUBSTRATE AND DISPLAY DEVICE
- DISPLAY APPARATUS, DISPLAY MODULE, ELECTRONIC DEVICE, AND METHOD OF MANUFACTURING DISPLAY APPARATUS
- DISPLAY PANEL, MANUFACTURING METHOD, AND MOBILE TERMINAL
This application is a continuation of patent application Ser. No. 09/740,679 filed Dec. 19, 2000 which was a continuation of patent application Ser. No. 08/987,531 filed Dec. 9, 1997, now U.S. Pat. No. 6,197,059 which is a continuation-in-part of patent application Ser. No. 08/640,118, filed Apr. 30, 1996, which is a continuation of Ser. No. 08/500,010 filed Jul. 10, 1995, which is a continuation of Ser. No. 08/113,215, filed Aug. 27, 1993, which is a continuation-in-part of Ser. No. 08/020,630 now U.S. Pat. Nos. 5,476,514, 5,672,282, and 5,496,366, which is a continuation-in-part of Ser. No. 07/515,636, now abandoned.
BACKGROUND OF THE INVENTION1. Field of the Invention
This invention relates generally to intraocular lenses and more particularly to novel accommodating intraocular lenses for implantation within the capsular bag of a human eye from which the natural lens matrix has been removed by an, extraction procedure which leaves intact within the eye the posterior capsule and an anterior capsule remnant of the natural lens. The invention relates also to a novel method of utilizing the intraocular lenses in a human eye to provide the patient with accommodation capability responsive to normal ciliary muscle action.
2. Prior Art
The human eye has an anterior chamber between the cornea and the iris, a posterior chamber behind the iris containing a crystalline lens, a vitreous chamber behind the lens containing vitreous humor, and a retina at the rear of the vitreous chamber. The crystalline lens of a normal human eye has a lens capsule attached about its periphery to the ciliary muscle of the eye by zonules and containing a crystalline lens matrix. This lens capsule has elastic optically clear anterior and posterior membrane-like walls commonly referred by ophthalmologists as anterior and posterior capsules, respectively. Between the iris and ciliary muscle is an annular crevice-like space called the ciliary sulcus.
The human eye possesses natural accommodation capability. Natural accommodation involves relaxation and constriction of the ciliary muscle by the brain to provide the eye with near and distant vision. This ciliary muscle action is automatic and shapes the natural crystalline lens to the appropriate optical configuration for focusing on the retina the light rays entering the eye from the scene being viewed.
The human eye is subject to a variety of disorders which degrade or totally destroy the ability of the eye to function properly. One of the more common of these disorders involves progressive clouding of the natural crystalline lens matrix resulting in the formation of what is referred to as a cataract. It is now common practice to cure a cataract by surgically removing the cataractous human crystalline lens and implanting an artificial intraocular lens in the eye to replace the natural lens. The prior art is replete with a vast assortment of intraocular lenses for this purpose. Examples of such lenses are described in the following patents: U.S. Pat. Nos. 4,254,509, 4,298,996, 4,842,601, 4,963,148, 4,994,082, 5,047,051.
As is evident from the above patents, intraocular lenses differ widely in their physical appearance and arrangement. This invention is concerned with intraocular lenses of the kind having a central optical region or optic and haptics which extend outward from the optic and engage the interior of the eye in such a way as to support the optic on the axis of the eye. My above-listed U.S. Pat. No. 5,047,051, discloses an intraocular lens having a haptic anchor plate, an optic at the longitudinal center of the plate, and resilient haptic loops staked to the ends of the plate.
Up until the late 1980's, cataracts were surgically removed by either intracapsular extraction involving removal of the entire human lens including both its outer lens capsule and its inner crystalline lens matrix, or by extracapsular extraction involving removal of the anterior capsule of the lens and the inner crystalline lens matrix but leaving intact the posterior capsule of the lens. Such intracapsular and extracapsular procedures are prone to certain post-operative complications which introduce undesirable risks into their utilization. Among the most serious of these complications are opacification of the posterior capsule following extracapsular lens extraction, intraocular lens decentration, cystoid macular edema, retinal detachment, and astigmatism.
An improved surgical procedure called anterior capsulotomy was developed to alleviate the above and other post-operative complications and risks involved in intracapsular and extra-capsular cataract extraction. Simply stated, anterior capsulotomy involves forming an opening in the anterior capsule of the natural lens, leaving intact within the eye a capsular bag having an elastic posterior capsule, and anterior capsular remnant or rim about the anterior capsule opening, and an annular sulcus, referred to herein as a capsular bag sulcus, between the anterior capsule remnant and the outer circumference of the posterior capsule. This capsular bag remains attached about its periphery to the surrounding ciliary muscle of the eye by the zonules of the eye. The cataractous natural lens matrix is extracted from the capsular bag through the anterior capsule opening by phacoemulsification and aspiration or in some other way after which an intraocular lens is implanted within the bag through the opening.
A relatively recent and improved form of anterior capsulotomy known as capsulorhexis is essentially a continuous tear circular or round capsulotomy. A capsulorhexis is performed by tearing the anterior capsule of the natural lens capsule along a generally circular tear line substantially coaxial with the lens axis and removing the generally circular portion of the anterior capsule surrounded by the tear line. A continuous tear circular capsulotomy or capsulorhexis, if performed properly, provides a generally circular opening through the anterior capsule of the natural lens capsule substantially coaxial with the axis of the eye and surrounded circumferentially by a continuous annular remnant or rim of the anterior capsule having a relatively smooth and continuous inner edge bounding the opening. When performing a continuous tear circular capsulorhexis, however, the anterior rim is often accidentally torn or sliced or otherwise ruptured, or the inner rim edge is nicked or sliced in a manner which renders the rim prone to tearing when the rim is stressed, as it is during fibrosis as discussed below.
Another anterior capsulotomy procedure, referred to as an envelope capsulotomy, involves cutting a horizontal incision in the anterior capsule of the natural lens capsule, then cutting two vertical incisions in the anterior capsule intersecting and rising from the horizontal incision, and finally tearing the anterior capsule along a tear line having an upper upwardly arching portion which starts at the upper extremity of the vertical incision and continues in a downward vertical portion parallel to the vertical incision which extends downwardly and then across the second vertical incision. This procedure produces a generally archway-shaped anterior capsule opening centered on the axis of the eye. The opening is bounded at its bottom by the horizontal incision, at one vertical side by the vertical incision, at its opposite vertical side by the second vertical incision of the anterior capsule, and at its upper side by the upper arching portion of the capsule tear. The vertical incision and the adjacent end of the horizontal incision form a flexible flap at one side of the opening. The vertical tear edge and the adjacent end of the horizontal incision form a second flap at the opposite side of the opening.
A third capsulotomy procedure, referred to as a beer can or can opener capsulotomy, involves piercing the anterior capsule of the natural lens at a multiplicity of positions along a circular line substantially coaxial with the axis of the eye and then removing the generally circular portion of the capsule circumferentially surrounded by the line. This procedure produces a generally circular anterior capsule opening substantially coaxial with the axis of the eye and bounded circumferentially by an annular remnant or rim of the anterior capsule. The inner edge of this rim has a multiplicity of scallops formed by the edges of the pierced holes in the anterior capsule which render the annular remnant or rim prone to tearing radially when the rim is stressed, as it is during fibrosis as discussed below.
Intraocular lenses also differ with respect to their accommodation capability, and their placement in the eye. Accommodation is the ability of an intraocular lens to accommodate, that is to focus the eye for near and distant vision. My U.S. Pat. No. 5,326,347 and certain of the earlier listed patents describe accommodating intraocular lenses. Others of the listed patents describe non-accommodating intraocular lenses. Most non-accommodating lenses have single focus optics which focus the eye at a certain fixed distance only and require the wearing of eye glasses to change the focus. Other non-accommodating lenses have bifocal optics which image both near and distant objects on the retina of the eye. The brain selects the appropriate image and suppresses the other image, so that a bifocal intraocular lens provides both near vision and distant vision sight without eyeglasses. Bifocal intraocular lenses, however, suffer from the disadvantage that each bifocal image represents only about 40% of the available light and the remaining 20% of the light is lost in scatter.
There are four possible placements of an intraocular lens within the eye. These are (a) in the anterior chamber, (b) in the posterior chamber, (c) in the capsular bag, and (d) in the vitreous chamber.
SUMMARY OF THE INVENTIONAccording to one of its aspects, this invention provides improved accommodating intraocular lenses to be implanted within the capsular bag of a human eye which remains in the eye after removal of the natural matrix from the human lens capsule through an anterior capsule opening created by an anterior capsulotomy and preferably by a capsulorhexis. An improved accommodating intraocular lens according to the invention has a central optic and haptics which extend outward from diametrically opposite sides of the optic and are movable anteriorly and posteriorly relative to the optic. In some described lens embodiments, the haptics are joined at their inner ends to the optic by hinge-like junctions referred to herein as hinges, and the anterior/posterior movement of the haptics involves pivotal movement of the haptics at these hinges. In other described embodiments, the haptics are resiliently flexible, and the anterior/posterior movement of the haptics relative to the optic involves resilient flexing or bending of the haptics. In this regard, it is important to note at the outset that the terms “flex”, “flexing”, “flexible”, and the like are used herein in a broad sense to cover both hinged and resiliently bendable haptics.
Certain of the lens embodiments described herein are referred to as simple plate haptic lenses. These simple plate haptic lenses are intended for use when the capsulotomy procedure utilized in the eye surgery is properly performed and provides an anterior capsule remnant or rim that is not only completely intact and free of splits, tears, and the like at the time of lens implantation but is also likely to remain intact during subsequent fibrosis. Other described lens embodiments are referred to as a plate haptic spring lens. These latter lenses are intended for use in those situations in which the capsulotomy produces an anterior capsular remnant which is not intact or which is not likely—to remain intact during fibrosis. Both types of lenses are designed for implantation within a capsular bag of the eye in a position wherein the lens optic is aligned on the axis of the eye with the anterior capsule opening in the bag, and the lens haptics are situated within the capsular bag sulcus in contact with the sulcus wall. The normally posterior side of the lens then faces the elastic posterior capsule of the bag.
The presently preferred lens embodiments of the invention have round optics and haptics joined at their inner ends to opposite edges of the optic by relatively narrow junctions. These junctions occupy only relatively small diametrically opposite edge portions of the optics and leave unobstructed the remaining major circular edge portions of the optic between the junctions. In the preferred lenses described herein, these junctions are hinge junctions about which the haptics are movable anteriorly and posteriorly relative to the optic. These flexible or hinged junctions form a bridge between the optic and the plate haptic which is fixed in position within the anterior and posterior capsules by fibrosis. The bridges are tapered, the widest end being adjacent to the optic. This allows the bridge to slide in and out of the pocket formed by the fibrosed anterior capsular rim and the posterior capsule, and enables the optic to move anteriorly when the plate haptics are subjected to end to end compression.
During a post operative healing period on the order of three weeks, active endodermal cells on the posterior side of the anterior capsular rim cause fusion of the rim to the elastic posterior capsule by fibrosis. Fibrosis occurs about the haptics in such a way that the haptics are effectively “shrink-wrapped” by the capsular bag and form radial pockets between the anterior rim and the posterior capsule. These pockets contain the haptics and act to position and center the lens in the eye. The anterior capsular rim shrinks during fibrosis. This shrinkage combined with shrink-wrapping of the haptics causes endwise compression of the lens in a manner which tends to deflect the center of the lens along the axis of the eye relative to the fixated outer haptic ends. The intact fibrosed capsular rim prevents forward deflection of the lens, so that fibrosis-induced deflection of the lens occurs rearwardly to a position in which the lens presses against the elastic posterior capsule and stretches this capsule rearwardly.
Relaxation of the ciliary muscle during normal use of the eye after completion of fibrosis stretches the capsular bag and the fibrosed anterior capsular rim. The rim is stretched to a taut trampoline-like condition in which the rim deflects the lens rearwardly to and holds the lens in a posterior position. In this position of the lens, which is its distant vision position, the lens optic presses rearwardly against and stretches the elastic posterior capsule. The stretched posterior capsule then exerts a forward bias force on the lens.
The accommodating lenses of the invention are uniquely constructed and arranged to utilize the fibrosed anterior capsular rim, the elastic posterior capsule, the vitreous cavity pressure, and the natural brain-controlled ciliary muscle action of the eye to provide postoperative accommodation for near vision. Thus, when looking at a near object, the brain constricts the ciliary muscle. This relaxes the fibrosed anterior rim, increases vitreous cavity pressure, and compresses the lens endwise in such a way as to effect forward deflection, i.e. accommodation movement, of the lens optic along the axis of the eye to a near vision position. Depending upon the amount of accommodation, accommodation deflection of the lens is produced initially by the increase in vitreous pressure and the forward bias force of the stretched posterior capsule and finally by forward buckling of the lens in response to endwise compression of the lens. Subsequent brain-activated relaxation of the ciliary muscle stretches the capsular bag and the fibrosed anterior capsular rim to return the lens rearwardly toward its distant vision position.
The preferred lens embodiments of the invention have round optics which are sized in diameter to pass through the anterior capsule opening. These preferred lenses are constructed and arranged for anterior accommodation movement of their optics to positions wherein the optics project through the anterior capsule opening to maximize the accommodation range of the lenses.
According to another important aspect of the invention, the ciliary muscle is paralyzed in its relaxed state at the start of surgery and is maintained in this relaxed state during both surgery and post-operative fusion of the anterior capsular remnant or rim to the posterior capsule by fibrosis. The ciliary muscle is thus relaxed by introducing a ciliary muscle relaxant (i.e. a cycloplegic) into the eye. While various cycloplegics may be used, the preferred cycloplegic is atropine because of its relatively long effective period compared to other cycloplegics. The cycloplegic is initially introduced into the eye at the start of surgery to dilate the pupil and paralyze the ciliary muscle in its relaxed state. After surgery, cycloplegic drops are periodically introduced into the eye by the patient during a postoperative healing period of sufficient duration (normally about two to three weeks) to maintain the ciliary muscle in its relaxed state until fibrosis is complete. This drug-induced relaxation of the ciliary muscle prevents contraction of the muscle and immobilizes the capsular bag during fibrosis. By this means, the lens is fixed in position within the eye relative to the retina for distance vision. When the cycloplegic effect wears off and the ciliary muscle can contract again, the contraction causes end to end compression on the plates thus moving the optic anteriorly for near vision. If the ciliary muscle was not maintained in its relaxed state, the muscle would undergo essentially normal brain-induced vision accommodation contraction and relaxation during fibrosis.
This ciliary muscle action during fibrosis would not only result in improper formation of the haptic pickets in the fibrose tissue, but also ciliary muscle contraction during fibrosis would compress the capsular bag radially and the lens endwise in such a way as to very likely dislocate the lens from its proper position in the bag.
An accommodating lens according to the invention may have a normal unstressed configuration, such that when deflected from its normal unstressed configuration, the lens develops internal elastic strain energy forces which bias the lens toward its normal unstressed configuration in a manner which aids accommodation. The lens may be generally flat, anteriorly arched, or posteriorly arched in this normal unstressed configuration. One disclosed embodiment of the lens includes auxiliary springs for aiding lens accommodation. Some disclosed lens embodiments have integral fixation means at the haptic ends around which fibrosis of the anterior rim of the capsular bag occurs to fix the lens against dislocation in the eye. Other disclosed embodiments have fixation elements from which the lens proper is separable to permit later removal of the lens for repair or correction and replacement of the lens in its exact original position within the eye.
As noted earlier, the simple plate haptic lens of the invention is designed for use when the anterior capsulotomy performed on the eye provides an anterior capsular remnant or rim that remains intact and circumferentially continuous throughout fibrosis. The plate haptic spring lenses are designed for use when the anterior capsular remnant or rim of the capsular bag is ruptured, that is cut or tom, or is liable to become so during fibrosis. A ruptured capsular rim may be produced in different ways. For example, improper performance of a continuous tear circular capsulotomy, or capsulorhexis, may result in accidental cutting or tearing of the anterior rim. A beer can or can opener capsulotomy, on the other hand, produces an anterior capsular rim which is not intact and has an inner scalloped edge having stress-inducing regions that render the rim very prone to tearing during surgery or subsequent fibrosis. An envelope capsulotomy inherently produces an anterior capsular remnant which is ruptured and not intact.
A ruptured anterior capsular remnant or rim may preclude utilization of a simple plate haptic lens of the invention for the following reasons. A ruptured rim may not firmly retain the lens haptics in the sulcus of the capsular bag during fibrosis, thereby rendering the lens prone to decentration and/or posterior or anterior dislocation. A ruptured capsular rim may be incapable of assuming the taut trampoline-like condition of a non-ruptured rim. If so, a ruptured capsular rim is incapable of effecting full posterior deflection of a plate haptic lens to a distant viewing position against the posterior capsule during and after fibrosis. In fact, a ruptured capsular rim may permit anterior deflection of the lens. In either case, since the power of the lens is selected for each individual patient and is dependent upon their spectacle power, and since good vision without glasses requires the lens optic to be at precisely the correct distance from the retina, a simple plate haptic lens of the invention may not be acceptable for use with a ruptured anterior capsular remnant or rim.
The accommodating plate haptic spring lenses of the invention are designed for use when the anterior capsular remnant or rim of the capsular bag is ruptured. These plate haptic spring lenses are similar to the simple plate haptic lenses but have resilient springs, such as spring loops, at the ends of the plate haptics. When a plate haptic spring lens is implanted in a capsular bag, the haptic springs press outward against the wall of the capsular bag sulcus to fixate the lens in the bag during fibrosis. Fibrosis occurs about the springs in such a way as to effect fusion of the ruptured anterior remnant to the posterior capsule, firm fixation of the springs and hence the haptics in the bag, and posterior deflection of the lenses against the elastic posterior capsule during fibrosis. Brain-induced constriction and relaxation of the ciliary muscle after fibrosis with a ruptured capsular rim effects accommodation of the plate haptic spring lens in much the same way as occurs with the simple plate haptic lens and an intact non-ruptured capsular rim.
While the plate haptic spring lenses of the invention are designed for use with a ruptured anterior capsular remnant or rim, these lenses can also be utilized with an intact rim. A plate haptic spring lens also compensates for improper lens placement in the eye with one end of the lens situated in the capsular bag and the other end of the lens situated in the ciliary sulcus of the eye. In this regard, an advantage of the plate haptic spring lenses of the invention over the simple plate haptic lenses resides in the fact that the spring lenses eliminate the need to have on hand in the operating room both a simple plate haptic lens for use with an intact capsular rim and a plate haptic spring lens as a substitute for the plate haptic lens in the event the rim is ruptured during surgery.
Another advantage of the plate haptic spring lenses over the simple plate haptic lenses of the invention resides in the fact that the haptic spring lenses permit an optic of larger diameter than those of simple plate haptic lenses whose optic diameters will normally be restricted to the range of 4-7 mm. Thus, the haptic spring lenses rely on the haptic springs rather than the capsular remnant or rim to retain the lenses in position during fibrosis. As a consequence, these lenses may be used with a capsular remnant or rim of reduced radial width or a capsular rim which is slit or torn, both of which rim types provide an anterior capsule opening of larger effective size than those possible with a simple plate haptic lens. A larger anterior capsule opening, in turn, permits a larger optic diameter which offers certain opthalmological benefits. According to one aspect of this invention, such a large opening is provided after fibrosis is complete by using a laser to slit the anterior capsular rim radially or cut the rim circumferentially to enlarge the opening.
A further aspect of the invention concerns a novel method of utilizing an accommodating lens of the invention to provide accommodation in a human eye whose natural lens matrix has been removed from the lens capsule by a procedure involving anterior capsulotomy of the natural lens. The method may be utilized to replace a natural lens from which a cataract has been removed and to correct a refractive error in the eye of a patient who previously wore glasses in order to enable the patient to see well without glasses. For example, the invention can be utilized to correct refractive errors and restore accommodation to persons in their mid-40's who require reading glasses or bifocals for near vision by replacing the clear non-cataracrous crystalline lens matrix of their eyes with an accommodating intraocular lens according to the invention. According to the method of utilizing a plate haptic spring lens of the invention, the anterior capsular remnant or rim of the capsular bag is slit radially or cut to enlarge the anterior capsule opening after fibrosis is complete to permit the use of a lens with a relatively large diameter optic larger than 6 or 7 mm.
BRIEF DESCRIPTION OF THE DRAWINGS
Turning now to these drawings and first to
As mentioned earlier, continuous tear circular capsulotomy, or capsulorhexis, involves tearing the anterior capsule A along a generally circular tear line in such a way as to form a relatively smooth-edged circular opening in the center of the anterior capsule. The cataract is removed from the natural lens capsule through this opening. After completion of this surgical procedure, the eye includes an optically clear anterior cornea 12, an opaque sclera 14 on the inner side of which is the retina 16 of the eye, an iris 18, a capsular bag 20 behind the iris, and a vitreous cavity 21 behind the capsular bag filled with the gel-like vitreous humor. The capsular bag 20 is the structure of the natural lens of the eye which remains intact within the eye after the continuous tear circular tear capsulorhexis has been performed and the natural lens.
The capsular bag 20 includes an annular anterior capsular remnant or rim 22 and an elastic posterior capsule 24 which are jointed along the perimeter of the bag to form an annular crevice-like capsular bag sulcus 25 between rim and posterior capsule. The capsular rim 22 is the remnant of the anterior capsule of the natural lens which remains after capsulorrhexis has been performed on the natural lens. This rim circumferentially surrounds a central, generally round anterior opening 26 (capsulotomy) in the capsular bag through which the natural lens matrix was previously removed form the natural lens. The capsular bag 20 is secured about its perimeter to the ciliary muscle of an eye by zonules 30.
Natural accommodation in a normal human eye having a normal human crystalline lens involves automatic contraction or constriction and relaxation of the ciliary muscle of the eye by the brain in response to looking at objects at different distances. Ciliary muscle relaxation, which is the normal state of the muscle, shapes the human crystalline lens for distant vision. Ciliary muscle contraction shapes the human crystalline lens for near vision. The brain-induced change from distant vision to near vision is referred to as accommodation.
Implanted within the capsular bag 20 of the eye 10 is an accommodating intraocular lens 32 according to this invention which replaces and performs the accommodation function of the removed human crystalline lens. Lens 32 is referred to in places as a simple plate haptic lens to distinguish it from the later described plate haptic spring lens of the invention. As mentioned earlier and will become readily understood as the description proceeds, the accommodating intraocular lens may be utilized to replace either a natural lens which is virtually totally defective, such as a cataractous natural lens, or a natural lens that provides satisfactory vision at one distance without the wearing of glasses but provides satisfactory vision at another distance only when glasses are worn. For example, the accommodating intraocular lens of the invention can be utilized to correct refractive errors and restore accommodation for persons in their mid-40's who require reading glasses or bifocals for near vision.
Intraocular lens 32 comprises a body 33 which may be formed of relatively hard material, relatively soft flexible semi-rigid material, or a combination of both hard and soft materials. Examples of relatively hard materials which are suitable for the lens body are methyl methacrylate, polysulfones, and other relatively hard biologically inert optical materials. Examples of suitable relatively soft materials for the lens body are silicone, hydrogels, thermolabile materials, and other flexible semi-rigid biologically inert optical materials.
The lens body 33 has a generally rectangular shape and includes a central optical zone or optic 34 and plate haptics 36 extending from diametrically opposite edges of the optic. The haptics have inner ends joined to the optic and opposite outer free ends. The haptics 36 are movable anteriorly and posteriorly relative to the optic 34, that is to say the outer ends of the haptics are movable anteriorly and posteriorly relative to the optic. The particular lens embodiment illustrated is constructed of a resilient semi-rigid material and has flexible hinges 38 which join the inner ends of the haptics to the optic. The haptics are relatively rigid and are flexible about the hinges anteriorly and posteriorly relative to the optic. These hinges are formed by grooves 40 which enter the anterior side of the lens body and extend along the inner ends of the haptics. The haptics 36 are flexible about the hinges 38 in the anterior and posterior directions of the optic. The lens has a relatively flat unstressed configuration, illustrated in
The accommodating intraocular lens 32 is implanted within the capsular bag 20 of the eye 10 in the position shown in
During a post-operative healing period on the order of two to three weeks following surgical implantation of the lens 32 in the capsular bag 20, epithelial cells under the anterior capsular rim 22 of the bag cause fusion of the rim to the posterior capsule 24 by fibrosis. This fibrosis occurs around the lens haptics 36 in such a way that the haptics are “shrink-wrapped” by the capsular bag 20, and the haptics form pockets 42 in the fibrosed material F (
The capsular rim 22 shrinks during fibrosis and thereby shrinks the capsular bag 20 slightly in its radial direction. This shrinkage combined with shrink wrapping of the lens haptics 36 produces some opposing endwise compression of the lens which tends to buckle or flex the lens at its hinges 38 and thereby move the lens optic 34 along the axis of the eye. Unless restrained, this flexing of the lens might occur either forwardly or rearwardly. The taut anterior capsular rim 22 pushes rearwardly against and thereby prevents forward flexing of the lens. This fibrosis-induced compression of the lens is not sufficient to interfere with proper formation of the haptic pockets in the fibrosed tissue or cause dislocation of the lens. Accordingly, endwise compression of the lens by fibrosis aided by the rearward thrust of the taut capsular rim against the lens haptics 36 causes rearward flexing of the lens from its initial position of
Ciliary muscle induced flexing of the lens 32 during fibrosis can be resisted or prevented by placing sutures within the hinge grooves 40. Removal of these sutures after completion of fibrosis may be accomplished by using sutures that are either absorbable in the fluid within the eye or by using sutures made of a material, such as nylon, which can be removed by a laser.
Natural accommodation in a normal human eye involves shaping of the natural crystalline lens by automatic contraction and relaxation of the ciliary muscle of the eye by the brain to focus the eye at different distances. Ciliary muscle relaxation shapes the natural lens for distant vision. Ciliary muscle contraction shapes the natural lens for near vision.
The accommodating intraocular lens 32 is uniquely constructed to utilize this same ciliary muscle action, the fibrosed capsular rim 22, the elastic posterior capsule 24, and the vitreous pressure within the vitreous cavity 21 to effect accommodation movement of the lens optic 34 along the optic axis of the eye between its distant vision position of
In this intermediate accommodation position, the lens is substantially flat, and the ends of the lens haptics and their hinges 38 are disposed substantially in a common plane normal to the axis of the eye. During the initial accommodation, the lens arches rearwardly so that endwise compression of the lens by ciliary muscle contraction produces a rearward buckling force on the lens which resists the initial accommodation. However, the increased vitreous cavity pressure and the forward bias force of the stretched posterior capsule are sufficient to overcome this opposing rearward buckling force and effect forward accommodation movement of the lens to and at least just slightly beyond the intermediate position of
The lens haptics 36 flex at their hinges 38 with respect to the lens optic 34 during accommodation. Any elastic strain energy forces developed in the hinges during this flexing produces additional anterior and/or posterior forces on the lens. For example, assume that the lens is relatively flat, i.e., that the lens haptics 36 lie in a common plane as shown in
During accommodation, the lens haptics 36 slide endwise in their fibrosed tissue pockets 42. As shown best in
Refer now to
The modified intraocular lenses of
The modified intraocular lens 140
The modified intraocular lens 150 illustrated in
The modified lens 160 of
Fibrosis of the capsular rim 22 occurs around the outer ends of the lens haptics 166 and the exposed outer ends of the fixation loops 164 and through the spaces between the haptics and the loops in such a way that the loops are firmly fixed in the capsular bag, and the haptics form pockets 42 in the fibrose tissue F. The posterior bias of the fibrosed capsular rim 22 urges the lens posteriorly to its distant vision position when the ciliary muscle 28 is relaxed, thereby stretching the posterior capsule 24 rearwardly in the same manner as explained in connection with
The fixation loops have holes 174 in their outer arched ends through which a suture 176 may be passed and tied to retain the loops and lens body in assembled relation during implantation of the lens in the capsular bag. This suture is removed at the conclusion of the surgery. Holes 174 may also be utilized to position the lens in the capsular bag during surgery. The lens haptics 166 are separable from and reengageable with the fixation loops 164. This permits the lens body 162 to be removed from the eye any time after surgery for correction or replacement of the lens optic 172 and then replaced in its original position in the eye.
The modified intraocular lens 180 of
The modified lens 220 of
When the lens 220 is implanted within the capsular bag 20 of the eye 10, the outer ends of the lens haptics 226 and the fixation pins 224 are disposed between the capsular rim 22 and posterior capsule 24 of the bag in much the same way as described in connection with
The modified intraocular lenses 260, 262 in
The modified intraocular lenses 270, 272 in
Referring to
The modified accommodating intraocular lens 290 of
The modified accommodating intraocular lens 310 of
The accommodating plate haptic lenses described to this point are referred to herein as simple plate haptic lenses. These lenses are intended for use when the anterior capsulotomy procedure performed on the eye provides an anterior annular capsular remnant or rim that remains intact and circumferentially continuous throughout fibrosis and has a sufficient radial width to retain the lens in the proper position within the capsular bag during and/or after fibrosis. According to another of its aspects, this invention provides modified accommodating intraocular lenses, illustrated in
As noted earlier, a ruptured capsular remnant or rim may occur in different ways. For example, continuous tear circular capsulotomy, or capsulorhexis, (
A ruptured anterior capsular remnant or rim may preclude utilization of a simple plate haptic lens of the invention for the following reasons. A ruptured rim may not firmly retain the lens haptics in the sulcus of the capsular bag during fibrosis. This renders the lens prone to decentration and/or dislocation, such as dislocation into the vitreous cavity if the posterior capsule tears or becomes cloudy over a period of time and is cut with a laser to provide a capsulotomy in the posterior capsule. A ruptured capsular rim may be incapable of assuming the taut trampoline-like condition of an intact capsular rim. As a consequence, a ruptured capsular rim may be incapable of effecting full posterior deflection of a plate haptic lens to a distant viewing position against the posterior capsule during and after fibrosis. A ruptured capsular rim may also permit anterior deflection of the lens during fibrosis. In either case, since the power of an intraocular lens is selected for each individual patient and may be dependent upon their spectacle power, and since good vision without glasses requires the lens optic to be situated at precisely the correct distance from the retina throughout the range of accommodation, a simple plate haptic lens of the invention may not be acceptable for use with a ruptured anterior capsular remnant or rim.
The plate haptic spring lens 420 is implanted within the capsular bag 20 of the eye in the same manner as described earlier in connection with the simple plate haptic lenses of the invention. That is to say, the lens 420 is implanted within the eye while its ciliary muscle 28 is paralyzed in its relaxed state, and the capsular bag is thereby stretched to its maximum diameter (9-11 mm). The overall length of the lens body 422 measured between the ends of the lens haptics 428 at either side of the haptic recesses 430 substantially equals the inner diameter of the stretched capsular bag. The overall length of the lens measured between the outer edges of the spring loops 424 at their centers when the loops are in their normal unstressed state is slightly greater than this inner diameter of the stretched capsular bag. For example, if the inner diameter of the stretched capsular bag is in the range 10-10.6 mm, the lens body 422 will have an overall length of 10-10.6 mm measured between the outer ends of the lens haptics, and the overall length of the lens measured between the centers of the unstressed spring loops will be in the range of 11-12.5 mm.
While the plate haptic spring lens 420 is designed for use with a ruptured anterior capsular remnant or rim, it can also be utilized with an intact rim. A plate haptic spring lens also compensates for improper lens placement in the eye with one end of the lens situated in the capsular bag and the other end of the lens situated in the ciliary sulcus of the eye since the spring loops will expand outwardly to engage both the inner edge of the bag and the wall of the ciliary sulcus. In this regard, an advantage of the plate haptic spring lenses of the invention over the simple plate haptic lenses resides in the fact that the spring lenses eliminate the need to have on hand in the operating room both a simple plate haptic lens for use with an intact capsular rim and a plate haptic spring lens as a backup for the plate haptic lens in the event the rim is ruptured during surgery.
Another advantage of the haptic spring lens 420 resides in the fact that it permits the lens to have a larger optic than a simple plate haptic lens whose optic diameters will normally be within the range of 4-7 mm. Thus, since the haptic spring lens relies on the spring loops 424 rather than on the capsular remnant or rim 22 to retain the lens in position during fibrosis, the lens may be used with a capsular remnant or rim of smaller radial width and hence larger diameter anterior capsule opening than those required for use of the simple plate haptic accommodating lenses. The larger diameter anterior capsule opening, of course, permits a larger optic diameter in the range of 7-9 mm which offers certain ophthalmological benefits.
The large diameter anterior capsule opening necessary to accommodate a large optic spring accommodating lens may be formed during the original surgery by a planned large continuous tear circular capsulorhexis, a beer can capsulotomy of the desired large diameter, a planned envelope capsulotomy or by cutting of radial slits into the anterior capsular rim during surgery after implanting the spring accommodating lens in the capsular bag. According to another of its aspects, the invention provides a method whereby the desired large anterior capsule opening may be formed after the original surgery following completion of fibrosis. This method involves slitting an annular capsular rim radially with a laser after fibrosis is complete into a number of flap-like remnants 434 (
The modified plate haptic spring lens 500 of
Haptics 906 have relatively wide outer end portions 910, inwardly tapered central portions 912, and relatively narrow tapered inner end portions 914. The inner end portions 914 are joined to diametrically opposite edge portions of the round optic 904. The width of the outer end portions 910 of the haptics measured transverse to the length of the lens approximates the diameter of the optic. The width of the inner haptic end portions 914 measured transverse to the length of the lens is substantially less than the diameter of the optic. The outer end portions 910 and tapered central portions 912 of the haptics occupy the major length of the haptics measured in the lengthwise direction of the lens. The tapered inner end portions 914 of the haptics taper inwardly to a progressively narrower width toward the outer ends of the haptics. These inner end portions effectively form bridges between the optic and the wide outer major portions 910 of the haptics. The inner haptic end portions contain V-grooves 916 which extend across the anterior sides of these end portions transverse to the length of the lens close to and preferably in virtually tangential relation to the edge of optic 904.
The outer end portions 910 of the haptics 906 contain relatively large openings 918 in the form of cutouts which open through the outer ends of the haptics. Joined at one end to the outer ends of the haptics, at one side of the open ends of the haptic cutouts 918, are spring arms 920. These arms extend laterally across the outer haptic ends and are resiliently flexible endwise of the lens.
As shown in
Referring to
The anterior offset of the optic 904 in the preferred lens 900 provides two advantages. One of these advantages resides in the fact that the arrangement of the hinge junctions 908 resulting from the anterior offset of the optic 904 aids anterior buckling of the lens and thereby accommodation movement of the optic relative to the outer ends of the haptics 906 in response to endwise compression of the lens by contraction of the ciliary muscle 28. The other advantage resides in the fact that the hinge junctions 908 which join the haptics 906 to the diametrically opposite edge portions of the optic 904 are relatively narrow compared to the diameter of the optic and are preferably narrower than the radius of the bag, as shown. The hinge junctions thus occupy only relatively small circumferential edge portions of the optic. The remaining circumferential edge portions of the optic between the junctions are free edge portions which are totally unobstructed by the haptics and taken together constitute a major portion of the optic circumference. The diameter of the optic is made to approximate or be slightly smaller than the anterior capsule opening 26 in the capsular bag in which the lens is implanted. These features of the lens enable the lens to undergo increased anterior accommodation movement from its posterior distant vision position of
The actual dimensions of the preferred lens may vary depending upon the patient's ocular dimensions. Following are typical lens dimensions:
In the lens 900 of
The modified accommodating intraocular lens 900b of
The modified accommodating lens 900c of
The lenses 900a, 900b, 900c of
Less inert materials utilized for intraocular lens components are preferably selected to provide optimum fixation of lens portions in the peripheral portions of capsular bags, and to provide optimum centration of the lens. Less fibrosis is formed about components formed of inert materials than about less inert materials. The less inert materials result in greater fibrosis being produced about the components. Such materials include PMMA, Acrylic, Prolene (a Nylon) and Polyimide.
Fibrosis forms more tightly about those materials which are less inert, for the reason that the body treats such materials as foreign objects. Lens features such as protuberances, arms and loops, are preferably formed of less inert material, and features intended for relative sliding movement in a capsular bag pocket formed by fibrosis, are formed of more inert materials, such as Silicone, Polyhema (Hydroxethyl methacrylate) or HEMA.
Referring now to
Lens 1000 is implanted in the capsular bag 20 in the same manner as the earlier described lenses and is subjected to the same ciliary muscle contraction and relaxation as the earlier described lenses during normal vision accommodation following completion of fibrosis. Lens 1000 is so sized and shaped that the posterior surfaces 1008 of its haptics 1004 and the posterior surface 1012 of its optic 1006 contact the posterior capsule 24 of the bag 20. When the lens 1000 occupies its posterior distant vision configuration of
Most of the accommodating intraocular lenses of the embodiments heretofore described have hinged extended portions in the form of haptics with resiliently flexible haptic hinges.
The accommodating intraocular lenses 1100a and 1100c of
The optic and each haptic plate may be molded or otherwise fabricated from any suitable intraocular lens material including materials earlier mentioned. These materials have suitable optical and other qualities for an intraocular lens. Some of the materials are sufficiently hard or firm to enable haptic hinge components to be molded or otherwise formed integrally with the haptic plates, and each haptic hinge groove to be molded or otherwise formed in the material of the lens optic, as shown. Each hinge portion of such embodiment would have a hinge groove or channel along the edge of the optic which opens laterally outward toward the optic, with each hinge groove being cylindrically curved, undercut and sized in transverse cross-section to pivotally receive the bead of the adjacent haptic tongue, whereby the bead is captivated in the groove and the respective haptic is pivotally movable within certain angles anteriorly and posteriorly relative to the optic.
The lens 1100a of
The modified lens 1100b of
Lens 1050 comprises a one piece lens structure having a central optic 1052 and flexibly hinged extended portions 1054 in the form of plate haptics extending generally radially from the optic. Each plate haptic 1054 is longitudinally tapered in width and thickness so as to widen in width and increase in thickness toward its inner end. Each plate haptic includes an inner plate portion 1056 which is integrally joined to an edge of the optic 1052 and inclines anteriorly relative to the optic toward its outer end, an outer plate portion 1058 joined to the outer end of the inner plate portion, and a V-groove 1060 entering at the juncture of these plate portions so as to form at this juncture a flexible hinge 1062. The outer plate portion 1058 is pivotally movable at this hinge anteriorly and posteriorly relative to the inner plate portion 1056 and the optic 1052. The lens structure including its optic and haptic plate portions 1056, 1058 is molded or otherwise formed as a unitary lens structure from a lens material mentioned earlier and has inserts 1064 fixed in the outer ends of the outer haptic plate portions 1058. These inserts provide the lens extended portions or haptics 1054 and may be utilized to reinforce the outer haptic plate portions 1058 if necessary.
Lens 1050 implanted in the capsular bag 20 of the eye with the ciliary muscle of the eye paralyzed in its relaxed state and maintained in this paralyzed state until the completion of fibrosis, all in the same manner as explained earlier. During this fibrosis, the lens optic 1052 is urged posteriorly to its distant vision position shown in solid lines in
As mentioned above, lens 1050 is an anteriorly biased lens. In this regard, it will be observed in
An important feature of lens 1050 is that its optic 1052 has increased optical or dioptic power which aids the anterior biased configuration of the lens to further increase accommodation amplitude and diopters of accommodation. To this end, the anterior face 1066 of the optic is relatively flat or just slightly convex while the posterior face 1068 of the optic has a relatively steep convex curvature such that the optic has a generally planoconvex shape. This optic shape locates most or all of the optical power of the optic at the posterior side of the optic. Increasing the power of the lens optic in this way decreases the distance through which the optic must move to produce any given amount of vision accommodation and, conversely, increases the amount of vision accommodation produced by any given accommodation movement of the optic and thereby increases the maximum accommodation amplitude and diopters of accommodation of the lens.
Increasing the power of an intraocular lens optic at the posterior side of the optic, as in
The haptics or extended portions include plates 1206 which have inner ends joined to the optic and with outer free ends, and laterally extending flexible fixation fingers 1208 at the outer ends. Openings 1209 are defined in the outer ends of each fixation finger for improved fixation by fibrosis.
Haptic plates 1206 are longitudinally tapered to narrow in width in the outward direction, and have a width throughout their length less than the diameter of the optic. The haptics and their outer ends are movable anteriorly and posteriorly relative to the optic. Hinges, 1210 are defined by grooves in the haptics which enter either anterior or posterior sides and extend across inner end portions of the haptic plates 1206.
The lens has a relatively flat unstressed configuration wherein haptics 1204 and their hinges are disposed in a generally common plane. The outer edges of the haptic plates and the fingers 1208 may preferably be generally circularly curved about the axis of optic 1202. In their normal unstressed state, the fingers extend laterally outwardly from opposite longitudinal edges of respective haptic plates. When unstressed, fingers 1208 are preferably bowed with slight inward curvature.
Deformation of the lens from the normal unstressed configuration by anterior or posterior deflection of the haptics produces elastic strain energy forces in the hinges which urge the lens to its normal unstressed configuration.
The embodiments of
The intraocular lens 1300 of
Two pairs of the haptics extend oppositely from the optic, and a loop 1310 extends between each pair of haptics, and is secured to the haptics. An arm 1312 extends'from an arcuate transverse portion of each loop 1310 at an acute angle from the transverse portion. Each arm 1312 has an end protuberance defining an opening 1314 for improved fixation and centration.
Thus there has been shown and described a novel accommodating intraocular lens which fulfills all the objects and advantages sought therefor. Many changes, modifications, variations and other uses and applications of the subject invention will, however, become apparent to those skilled in the art after considering this specification together with the accompanying drawings and claims. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow.
Claims
1. An accommodating intraocular lens wherein the lens comprises flexible lens body having normally anterior and posterior sides, including a single solid biconvex optic said lens body, having two or more flexible haptics extending from opposite edges of the optic such that the lens body configured to be urged anteriorly toward its near vision position toward the iris during accommodation when the ciliary muscle contracts, and the lens being sized to be implanted into the capsular bag of the eye.
2. An accommodating lens according to claim 1, where the lens is configured to move forward and backward relative to the outer ends of the extending haptics along the axis of the eye with ciliary muscle contraction and relaxation.
3. An accommodating lens according to claim 1, where the optic is configured to move forward and backwards relative to the outer ends of the extending haptics along the axis of the eye with ciliary muscle contraction and relaxation.
4. An accommodating lens according to claim 1, which in uniplanar.
5. An accommodating lens according to claim 1, which is vaulted forward.
6. An accommodating lens according to claim 1, which is vaulted backwards.
7. An accommodating lens according to claim 1, which is multi planar.
8. An accommodating lens according to claim 1, which is made from different materials.
9. An accommodating lens according to claim 1, whereby the extending portions are flexible plate haptics.
10. An accommodating lens according to claim 1, where the haptics are tapered end-wise in width.
11. An accommodating lens according to claim 1, where the haptics are tapered in thickness.
12. An accommodating lens according to claim 1, where the outer ends of the haptics are bounded along their outer ends by spring loops.
13. An accommodating lens according to claim 1, where the lens has springs in the form of U-shaped hoops.
14. An accommodating lens according to claim 1, where the fixation elements are generally U-shaped loops of biologically insert material.
15. An accommodating lens according to claim 1, where the lens has centration nipples projection end-wise from the outer ends of the lens haptics.
16. An accommodating lens according to claim 1, whereby the lens body is configured to be urged posteriorly to its distance vision position by the posterior bias of the capsular rim when the ciliary muscle relaxes and anteriorly towards its near vision position during accommodation by the stretched posterior capsule and increase in vitreous cavity pressure when the ciliary muscle contracts.
17. An accommodating lens according to claim 1, whereby projections extend outwardly anteriorly from the plate haptic surface.
18. An accommodating lens according to claim 1, where the lens has two pairs of flexible haptics extending from opposite sides of the optic the two pairs of flexible haptics being located diametrically opposite one another.
19. An accommodating lens according to claim 1, where the lens has four haptics being slender, curved arms and symmetrically tapered from relatively wide inner ends, which are joined to the lens optic, to relatively narrow outer ends.
20. An accommodating lens according to claim 18, where at the outer ends of the haptics are enlarged knobs.
21. An accommodating lens according to claim 18, where the inner ends of the haptics are grooves which form flexible hinges about which the haptics are flexible anteriorly and posteriorly of the optic.
22. An accommodating lens according to claim 1, where the lens had a pair of spring loops at each end.
23. An accommodating lens according to claim 1, where the haptics have relatively wide outer end portions and inwardly tapered central portions, the width of the inner haptic end portions measured transverse to the length of the lens is substantially less than the diameter of the optic, the inner end portions effectively forming bridges between the optic and the wide outer major portions of the haptics, and the outer ends of the haptics are spring arms which extend laterally across the outer haptic ends and are resiliently flexible.
24. An accommodating lens according to claim 1, where the optic is offset anteriorly relative to the haptics.
25. An accommodating lens according to claim 1, such that the outer ends of the flexible haptics can move anteriorly and posteriorly relative to the optic with changes in vitreous cavity pressure, internal elastic strain, and posterior capsule elasticity.
26. An accommodating lens according to claim 1, where the haptics are joined at the inner ends to the optic by hinge-like junctions allowing the haptics to move anteriorly and posteriorly relative to the optic.
27. An accommodating lens according to claim 1, where the haptics are resiliently flexible and the anterior posterior movement of the haptics relative to the optic involves resilient flexing or bending of the haptics.
28. An accommodating lens according to claim 1, where the haptics are plate haptics.
29. An accommodating lens according to claim 1, where the outer ends of the haptics have fixation means.
30. An accommodating lens according to claim 1, where the lens comprises a body which is formed of relatively hard material.
31. An accommodating lens according to claim 1, where the lens body is of relatively flexible semi-rigid material.
32. An accommodating lens according to claim 1, where the lens is made of a combination of both hard and soft materials, including one of silicone, hydrogels, or thermoliable material as soft materials.
33. An accommodating lens according to claim 1, where the outer ends of the haptics are movable anteriorly and posteriorly relative to the optic.
34. An accommodating lens according to claim 1, where the haptics are flexible about hinges anteriorly and posteriorly relative to the optic.
35. An accommodating lens according to claim 33, where the haptics have hinges formed by grooves.
36. An accommodating lens according to claim 1, where the haptics are tapered end-wise in width and thickness.
37. An accommodating lens according to claim 1, where the outer ends of the lens haptics have raised shoulders.
38. An accommodating intraocular lens wherein the lens comprises a flexible lens body having normally anterior and posterior sides, including a flexible optic, said lens body having two or more radially extending portions from the optic such that the lens is configured to move anteriorly with contraction of the ciliary body of the eye, and the lens being sized to be implanted into the capsular bag of the eye such that contractions of the ciliary muscle causes the lens within the capsular bag behind the iris to move forward towards the iris with its contraction.
39. An accommodating lens according to claim 38 wherein the lens is sized to not be in contact with the ciliary muscle through the capsular bag wall.
40. An accommodating lens according to claim 38 wherein the lens can move anteriorly and posteriorly.
41. An accommodating lens according to claim 38 wherein the optics can move anteriorly and posteriorly relative to the outer ends of the extending portion.
42. An accommodating lens according to claim 38 wherein internal elastic strain causes the lens to move anteriorly.
43. An accommodating lens according to claim 38 wherein posterior capsule elasticity causes the lens to move anteriorly.
44. An accommodating lens according to claim 38 wherein the optic is configured to move forward and backwards with ciliary muscle contraction and relaxation.
45. An accommodating lens according to claim 44 wherein the optic is configured to move along the axis of the eye relative to the outer ends of the extending portions.
46. An accommodating lens according to claim 38 which is uniplanar.
47. An accommodating lens according to claim 38 which is vaulted forward.
48. An accommodating lens according to claim 38 which is vaulted backwards.
49. An accommodating lens according to claim 38 which is multiplanar.
50. An accommodating lens according to claim 38 which is made from different materials.
51. An accommodating lens according to claim 38 wherein the extending portions are plate haptics.
52. An accommodating lens according to claim 38 wherein the extended portions are plate haptics with hinges.
53. An accommodating lens according to claim 38 wherein the extending portions are plate haptics with a narrowing of the plate junctions adjacent to the optic.
54. An accommodating lens according to claim 38 wherein constriction of the ciliary muscle produces forward movement of the lens optic within the capsular bag towards the iris for near vision.
55. An accommodating lens according to claim 38 wherein the extending portions comprise four diametrically opposite structures.
56. An accommodating lens according to claim 38 wherein the extending portions are plate haptics with raised shoulders at their outer ends on either or both surfaces.
57. An accommodating lens according to claim 38 wherein two or more extending portions comprise plate haptics with a groove across the plate haptic adjacent to the optic.
58. An accommodating lens according to claim 38 wherein the extending portions have knobs at the corners of the distal ends.
59. An accommodating lens according to claim 38 wherein two or more extending portions have lateral fixation devices which comprise loops.
60. An accommodating lens according to claim 38 wherein two or more extending portions have lateral fixation devices which comprise openings.
61. An accommodating lens according to claim 38 wherein the extending portions include hinged plate haptics with laterally extending flexible fixation fingers.
62. An accommodating lens according to claim 38 wherein the lens has extended hinged portions comprising plate haptics which include laterally extending flexible fixation fingers at their outer ends which may be made of material different from that of the haptic plates.
63. An accommodating lens according to claim 38 which has flexible or relatively rigid hinged plate haptics with haptic openings connected at their outer ends with an arch.
64. An accommodating lens according to claim 38 wherein the extending portions comprise two pairs of small haptics extending oppositely from the optic and a loop extending between each pair of haptics that is secured to the haptics.
65. An accommodating lens according to claim 38 wherein the optic is located posteriorly tot eh outer ends of the extending portions.
66. An accommodating lens according to claim 38 wherein the extending portions comprise plates flexible throughout their length whereby the optic is anterior to the outer ends of the plates.
67. An accommodating lens according to claim 38 wherein the extending portions comprise plates haptics with projections extending forward of the plate haptics.
68. An accommodating lens according to claim 38 wherein the extending portions comprise plate haptics which have one or more resilient springs at their distal ends.
69. An accommodating lens according to claim 38 wherein the optic is biconvex.
70. An accommodating lens according to claim 38 wherein the optic has a relatively flat front surface and a posterior surface with a smaller radius of curvature.
71. An accommodating lens according to claim 38 having a plurality of relatively small extension portions or haptic plates having hinges into which loops extend between each pair of the small plates haptics.
72. An accommodating lens according to claim 38 having a plurality of relatively small extension portions or haptic plates having hinges into which loops extend between each pair of the small plate haptics at the end of each loop there is an arcuate transverse portion extending at an acute angle from the transverse portion.
73. An accommodating lens according to claim 38 wherein the lens is sized to be in contact with the ciliary muscle through the capsular bag wall.
74. An accommodating intraocular lens comprising a flexible body including an optic to be placed within a capsular bag of the eye the optic having anterior and posterior sides and the lens having two or more extending portions from the optic, the extending portions having at their distal ends fixation devices such that the intraocular lens has four or more fixation points for centration and fixation in the periphery of a capsular bag of the eye, and the optic being adapted to move anteriorly upon ciliary muscle constriction.
75. A lens as in claim 74, wherein the fixation devices comprise enlarged knobs.
Type: Application
Filed: Oct 28, 2004
Publication Date: May 5, 2005
Applicant:
Inventor: J. Cumming (Anaheim, CA)
Application Number: 10/977,233