BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 diagrammatically illustrates a pair of optics for a multi-ocular system disposed with reference to the cornea and the retina.
FIG. 2 shows an example dual optic lens with haptics extending from one optic.
FIG. 3 is a plan view of the optic of FIG. 2 further illustrating T-shaped haptics.
FIG. 4 is a cross-sectional view showing the optics as well as plural spacers attaching the two optics together.
FIG. 5 is a further view of a posterior lens.
FIG. 6 is a further view of an anterior lens having a larger diameter than the posterior lens.
FIGS. 7
a-7b are side and plan views illustrating optics and suitable spacers.
FIGS. 8 through 12 are diagrammatic views illustrating different placements of lenses in the eye with FIG. 8 showing a conventional placement in the capsular bag, FIG. 9 showing two lenses in the capsular bag, FIG. 10 showing one lens in the capsular bag and one in the sulcus, FIG. 11 showing one lens in the bag and one in the anterior chamber, and FIG. 12 showing two optics integrally linked in the bag.
FIG. 13 shows the lens system in vitro.
FIG. 14 shows the lens system in vitro optic fibrosis.
FIG. 15 illustrates a human eye with a currently available accommodating intraocular lens.
Turning now to these drawings, and first to FIG. 15, there is illustrated a human eye 10 whose natural crystalline lens matrix has been removed from the natural lens capsule of the eye through an anterior opening in the capsule formed by an anterior capsulotomy, in this case a continuous tear circular capsulotomy, or capsulorhexis. As noted earlier, this natural lens matrix, which is normally optically clear, often becomes cloudy and forms a cataract which is cured by removing the matrix and replacing it with an artificial intraocular lens.
Continuous tear circular capsulotomy, or capsulorhexis, involves tearing the anterior capsule 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 matrix has been removed from the natural lens.
The capsular bag 20 includes an annular anterior capsular remnant or rim 22 and an elastic posterior capsule 24 which are joined along the perimeter of the bag to form an annular crevice-like cul-de-sac 25 between rim and posterior capsule. The capsular rim 22 is the remnant of the anterior capsule of the natural lens which remains after capsulorhexis 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 from the natural lens. The capsular hag 20 is secured about its perimeter to the ciliary muscle 28 of the 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 such as shown in U.S. Pat. No. 7,048,760 which replaces and performs the accommodation function of the removed human crystalline lens. 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 as described below can be utilized to correct refractive errors and restore accommodation for persons in their mid-40s who require reading glasses or bifocals for near vision.
Intraocular lens 32 comprises a unitary body 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.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The lens system comprises two optics fused together, one in front of the other, as will be further explained beginning with FIG. 1 below. T-shaped extended portions or plate haptics 36 extend from diametrically opposite edges of the optic. These haptics include haptic members or plates 36 proper having inner ends joined one or other of the optics and opposite outer free ends and lateral fixation fingers at their outer ends. The haptic plates 36 may be longitudinally tapered so as to narrow or widen in width toward their ends or may be wider in their periphery and narrower adjacent to the optic. The optical system 34 is movable anteriorly and posteriorly relative to the haptics 36. The preferred lens embodiment illustrated is constructed of a resilient semi-rigid material and has flexible hinges 38 which join the inner ends of the haptic plates 36 to one of the optics. The haptics are relatively rigid and are flexible about the hinges anteriorly and posteriorly relative to the optic. These hinges are formed by grooves 38 which enter either the anterior or posterior sides and extend across the inner ends of the haptic plates 36. The haptics 36 are flexible about the hinges 38 in the anterior and posterior directions of the optical system. The lens has a relatively flat unstressed configuration, wherein the haptics 36 and their hinges 38 are disposed in a common plane transverse to the optic axis of the optic 34. Deformation of the lens from this normal unstressed configuration by anterior or posterior movement of the haptics about their hinges creates in the hinges elastic strain energy forces which urge the lens to its normal unstressed configuration. The outer end edges of the haptics are preferably circularly curved to equal radii about the optic axis of the optic 34. Anterior movement of the optical system toward the iris also is aided by an increase in vitreous cavity pressure upon constriction of the ciliary muscle. Furthermore this increase in pressure can also deform one or both of the optic further aiding near vision.
Turning now to FIG. 1, the same diagrammatically illustrates the human eye 10, the cornea 12, the retina 16, and further including an anterior optic 40 and posterior optic 41. Although not shown in FIG. 1, normally the posterior optic 41 includes haptics 36 such as seen in FIGS. 2 and 3 (and FIG. 13). D1 represents the distance from the cornea 12 to the first optic 40 and D2 the space between the two optics 40 and 41. D2 typically ranges from 0 to 3.0 mm. one of the optics can have a torric surface.
The letters “r” represent the four possible radii of the two optics, and they range from 4.9 mm to 6.0 mm. RI1 represents the refractive index of the aqueous between the cornea 12 and first optic 40, RI1 and RI2′ represent the refractive indices of respective optics 40 and 41, RI1′ represents the aqueous between the two optics, and R3 represents the refractive index of the vitreous between posterior lens 41 and the retina 16. RI1 is typically 1.336, RI3 1.336, and RI2 1.427, D2 is 1.0 to 2.0 mm and typically 1.4 mm. The various radii, refractive indices and distances between the optics can be adjusted to give the greatest depth of focus.
FIG. 2 illustrates the multi-ocular lens system wherein the anterior optic 40 has a larger diameter than the posterior optic 41. The lens has haptics 36 with hinges 38 adjacent the optic 41. FIG. 3 is a plan view of the posterior optic 41 illustrating T-shaped haptics 36, hinges 38 adjacent the optic, and fixation fingers 44. FIG. 4 illustrates the manner in which the two optics 40 and 41 are spaced and can be sealed with posts 46, preferably with liquid silicone and heat. The design is such that the anterior optic 40 can attach to the posterior lens 41. As can be seen from FIGS. 9-11, the anterior optic 40 can have haptics and fixation fingers like lens 41.
FIGS. 5 through 7
b illustrate the posterior lens 41, anterior optic 40, and stakes 48, via which the anterior optic can be connected with suitable holes 50 or 50′ as seen in FIGS. 5 and 7b. The two optics 40 and 41 can be attached before implantation or after implantation. The anterior optic 40 can be detachable so that it can be changed after implantation to provide a power change or a torricity charge.
The lens 41 can have an optic diameter of 4.0-6.5 mm, length from haptic 36 end to end of 10.0-12.5 mm, loop 44 tip to loop tip 10.5-13.0 mm, hinge 38 width 1.0-5.0 mm and depth at base of 0.05-1.0 mm. Typical materials are silicone, acrylic or any suitable optical material, and polymide or other logs material such as PMAA.
Turning now to FIGS. 8 through 12, FIG. 8 is a schematic representation similar to FIG. 13 showing an optic 34 of a standard intraocular lens in the capsular bag 20. FIG. 9 diagrammatically illustrates both lenses 40 and 41 with haptics disposed in the capsular bag. FIG. 10 diagrammatically illustrates optic 41 in the capsular bag 20 and the anterior optic 40 in the sulcus.
FIG. 11 diagrammatically illustrates two individual lenses 41 in the capsular bag 20, and the lens 40 in the anterior chamber. FIG. 12 illustrates the lens system 40 and 41 integrally linked and disposed in the capsular bag. In each case, the posterior optic can be standard accommodating intraocular lens.
Either lens 40 or 41 can be a stabilized accommodating intraocular lens according to patent application Ser. No. 11/461,290 filed Jul. 31, 2006, Attorney Docket No. 13533.4069.
FIG. 13 shows the lens system in vitro. The lens system may be designed such that the haptics are attached to the anterior optic resulting in an anterior vault when the lens system is focused for distance as in FIG. 14 or to the posterior optic resulting in a posterior vault when the lens system is in the distance position. FIG. 14 shows the lens in vitro after fibrosis
While an embodiment of the present invention has been shown and described, various modifications may be made without departing from the scope of the present invention, and all such modifications and equivalents are intended to be covered.
Patent Application
20080046077
