US3866249A

US3866249A - Posterior chamber artificial intraocular lens

Info

Publication number: US3866249A
Authority: US
Inventors: Leonard Flom
Original assignee: Individual
Current assignee: Individual
Priority date: 1974-03-07
Filing date: 1974-03-07
Publication date: 1975-02-18
Anticipated expiration: 1992-02-18
Also published as: IL46637A0; IL46637A; AU7845275A; EG11637A; FR2262956A1; NL7502390A; ES435427A1; SE7502484L; BR7501277A; IT1051606B; FR2262956B3; JPS50122098A; DE2510099A1; GB1474139A; IN142427B; AR202741A1

Abstract

An artificial intraocular lens for implantation in the posterior chamber of an eye after intracapsular or extracapsular lens extraction comprises a transparent optical zone portion shaped similar to the natural lens and a plurality of prongs protruding forwardly from the periphery thereof, wherein after implantation of the artificial intraocular lens the prongs extend through the iris to anchor the lens in the posterior chamber of the eye. The prongs protrude forwardly from the lens and are curved so that the outer ends of the prongs extend generally along the periphery of the lens, and the prongs are preferably arranged in pairs with the prongs in each pair extending in opposite directions along the periphery of the lens. A peripheral flange may be provided surrounding the optical zone portion for attaching the prongs to the lens, and a plurality of openings may be provided in the flange adjacent to the optical zone portion to permit passage of aqueous fluid from the ciliary body to the anterior chamber. Also disclosed is an insertion necklace comprising a semirigid loop passed through the openings in the flange surrounding the optical zone portion to embrace and support the lens during implantation thereof. A handle is connected to the loop for holding and manipulating the lens. The loop may be cut for removal of the insertion necklace after implantation of the lens.

Description

United States Patent t191 Fiom [54] POSTERIOR CHAMBER ARTIFICIAL INTRAOCULAR LENS [76] Inventor: Leonard Fiom, Arlen Rd., Westport,

Conn. 06880 [22] Filed: Mar. 7, 1974 [21] Appl. No.: 448,966

'[52] U.S. CI. 3/13 [51] Int. Cl A61f 1/16, A6If l/24 [58] Field of Search 3/13, I; 351/160 [56] References Cited UNITED STATES PATENTS 2,834,023 5/1958 Lieb 3/1 3,673,616 7/1972 Fedorov et al 3/13 3,711,870 l/1973 Deitrick 3/13 FOREIGN PATENTS OR APPLICATIONS 810,232 3/1959 Great Britain 3/13 OTHER PUBLICATIONS A Weightless Iseikonic Intraocular Lens, by R. D. Binkhorst et al., American Journal of Ophthalmology, Vol. 58, No. l, July 1964, pages 73-78.

Primary Examiner- Ronald L. Frinks Attorney, Agent, or F rm-Wooster, Davis & Cifelli [57] ABSTRACT An artificial intraocular lens for implantation in the [45] Feb. 1'8, 1975 posterior chamber of an eyeeafter intracapsular or extracapsular lens extraction comprises a transparent optical zone portion shaped similar to the natural lens and a plurality of prongs protruding forwardly from the periphery thereof, wherein after implantation of the artificial intraocular lens the prongs extend through the iris to anchor the lens in the posterior chamber of the eye. The prongs protrude forwardly from the lens and are curved so that the outer ends of the prongs extend generally along the periphery of the lens, and the prongs are preferably arranged in pairs with the prongs in each pair extending in opposite directions along the periphery ofthe lens. A peripheral flange may be provided surrounding the optical zone portion for attaching the prongs to the lens, and a plurality of openings may be provided in the flange adjacent to the optical zone portion to permit passage of aqueous fluid from the ciliary body to the anterior chamber.

Also disclosed is an insertion necklace comprising a semirigid loop passed through the openings in the flange surrounding the optical zone portion to embrace and support the lens during implantation thereof. A handle is connected to the loop for holding and manipulating the lens. The loop may be cut for removal of the insertion necklace after implantation of the lens.

28 Claims, 13 Drawing Figures PATENTE() FEB l 8 |975 SHEET 1 of 3 0 ad M SHEET am 3 PATENTEU FEB] BIENS l PATENTEU FEB 1 8l975 SHEET 3 0F 3 POSTERIOR CHAMBER ARTIFICIAL INTRAOCULAR LENS BACKGROUND l. Field of the Invention This invention relates to an artificial intraocular lens for implantation in the posterior chamber of the eye to obviate aphakia, and further relates to a structure for supporting and handling the artificial intraocular lens during implanation thereof.

2. Prior Art When no lens is rpeseent in the eye, which is known as the aphakic condition or aphakia and is usually the result of intracapsular or extracapsular lens extraction, the eye does not have the ability to focus rays of light. Therefore the eye receives a blurred image and vision is impaired.

The most common solution for producing a focusing mechanism to obviate the aphakic condition is tointerpose contact lenses or spectacles or a combination thereof between the eye and the light entering therein.

However, both contact lenses and spectacles havev drawbacks when used in treatment of aphakia. Neither spactacles nor contact lenses can duplicate the natural optical system because they are positioned outside of the eye, which results in a shift of the optical center from the in vivo state. Because the optical center has been shifted, the image received by the eye is either distorted and/or changed in size. In particular, spectacles and/or contact lenses usually cannot be used to restore exactly binocular vision after removal or loss of the lens from one eye when the other eye continues to function normally.

Further, the most common reason for removal of a lens is the condition of lenticular opacity known as a cataract, which occurs primarily in aged persons who have difficulty in adjusting to contact lenses and in manipulating the contact lenses for insertion and removal. Cataracts are also common in animals such as dogs and horses, and contact lenses and/or spectacles are not suitable devices for their treatment.

The desirability of implanting an artificial lens within the eye to obviate the condition of aphakia is well known and accepted in countries such as England, Holland and Italy. However, practical devices for carrying out this desirable objective have not been prepared, although several devices have been used with a modicum of success.

ln approximately 1950 Harold Ridley developed an artificial intraocular lens which comprised an optical lens portion having three foot-like projections or feet extending radially outward therefrom. Ridley originally placed this lens in the posterior chamber of the eye, behind the iris, withthe feet resting against the ciliary body between the ciliary process and the base of the iris. However, positioning of this lens in the posterior chamber was abandoned because of instances of dislocation after implantation and failures from glaucoma and the like, probably caused by irritation of the ciliary body by the feet.

Ridleys failure with posterior chamber artificial lenses led him and others, such as D. P. Choyce, to turn their attention to intraocular artificial lenses implanted in the anterior chamber of the eye between the iris and the cornea. The particular lens used was similar to Ridleys original lens, and had radially protruding feet which accomplished positioning of the lens in front of the pupil. These efforts also met with limited success, primarily because of the problems of irritation of the eye by the supporting feet and dislocation of the lens from its desired position in front of the pupil.

lt should be noted that placement of the lens in the anterior chamber is an unnatural position, with the attendant problems of restoring accurate binocular vision. Also, an anterior chamber lens is not positioned adjacent to the hyloid membrane for supporting the vitreous humor, and instances of forward displacement of the vitreous humor and retinal detachment are more likely to occur when anterior chamber lenses are used.

E. Epstein and C. D. Binkhorst developed artificial intraocular lenses which rely on the constrictor muscle of the iris as the positioning mechanism. Epstein first designed a collar-stud implant, with the pupil constructed in its waist for positioning thereof, and later a Maltese Cross pupil-supported implant with two leaves anterior to the iris and two leaves at right angles to the others and behind the iris. Binkhorst developed an iridocapsular (two-loop) lens and an iris-clip (fourloop) lens. The former comprises a lens of larger diameter than the pupil and placed thereover so that the periphery engages the front of the iris, and further comprises two metal loops which protrude from the back of the lens and extend generally parallel with the back surface of the lens and behind the iris for clipping the lens to the iris. Binkhorsts iris-clip lens is similar except that the iris is held by two pairs of loops which flank the iris and support the lens in front of the pupil. In some instances the iris is sutured to the clips to secure the positioning of the lens. This type of lens is also unsatisfactory in several respects. It, by necessity, interferes with constriction of the pupil, and in fact fixes the size of the pupil. It is also an anterior chamber lens, wherein correct positioning of the optical center cannot be achieved.

J. G. F. Worst considered posterior placement of an artificial lens to be desirable and developed a lens having a pair of closely spaced openings for positioning behind the iris. A suture was placed through the two openings and attached the lens to the iris. Although it is not believed that Worsts buttom would cause irritation of the ciliary body, as did the earlier posterior lens of Ridley, the difficulty of the technique necessary to suture the lens in position without damaging the iris as well as the possibility that the suture would not hold or would tear out from the iris has limited the acceptance of Worsts lens.

An additional artificial lens designed for positioning in the posterior chamber is described in U.S. Pat. No. 3,711,870 to Deitrick. Deitricks lens comprises a central optical portion surrounding by a resilient silicone flange shaped to receive and nest against the ciliary body. The lens is to be held in place by suturing the resilient flange to the ciliary body. Although the medical worth of the Deitrick lens is not yet known, it is known that it would be difficult to place sutures where Deitrick directs and it is also known that there may be reluctance on the part of Ophthalmologists or Ophthalmologic surgeons to do so because of the many risks attendant with the irritation of the ciliary body.

Several of the prior art lenses are discussed in ari article by D. P. Choyce entitled History of lntraocular Implants which is printed in Annals of Ophthalmology, October, 1973. The article also includes a list of references from which further information concerning prior art intraocular lenses can be obtained.

Several of the above lenses rely on sutures placed in the iris for holding the lenses in position. It should be noted that the iris consists of spongy, flexible tissue which may be pulled and stretched to a limited degree without damaging it. However, the iris has the unique property of never healing together after being cut or damaged. Thus, if a suture pulls through the iris, the damage to the iris is permanent. Because sutures are generally of a small diameter, if a lens positioned and held by sutures is subjected to a dislocating force, the sutures may cut the iris, resulting in permanent damage.

SUMMARY OF THE INVENTION The artificial intraocular lens according to the invention herein is a posterior chamber lens, wherein all the advantages of natural positioning of the lens are achieved. The artificial intraocular lens is held in place by a plurality of prongs extending forwardly from and along the periphery of the lens, wherein the prongs pass through the iris. The prongs are angled to prevent the lens from being dislocated. In one embodiment the prongs are attached to a flange peripherally surrounding the optical portion of the lens, and openings are provided at the intersection of the lens and the flange to permit the free flow of aqueous produced by the ciliary body. In other embodiments, the prongs are attached to the outer periphery of the optical portion of the lens, and no flange is employed.

Thus, the artificial intraocular lens according to the invention herein is firmly held in the natural position of the posterior chamber. It requires no sutures, which simplifies the technique necessary for implantation thereof and also reduces the possibility of damage to the iris by sutures. The artificial intraocular lens according to the invention herein avoids any contact with the ciliary body, and thereby avoids the many serious risks attendant therewith.

The case with which the artificial intraocular lens may be implanted is enhanced by the provision of an insertion necklace which comprises a semirigid loop passed through two of the peripheral openings in the lens wherein the lens is embraced and carried by the insertion necklace. The loop terminates in a handle. Thus, the lens is easily held and manipulated during irnplantation, and because the insertion necklace is attached to the lens, the lens cannot be dropped or lost from the opthalmologic surgeons control. This is to be contrasted with the usual methods of holding an artificial intraocular lens by means of a forceps or other detachable instrument during implantation. The insertion necklace may be removed by cutting the loop and withdrawing from the lens after implantation has been accomplished.

True binocular vision may be achieved with the posterior chamber lens according to the invention herein, and complications from irritation of the ciliary body and/or forward displacement of the vitreous humor and retinal detachment are avoided.

OBJECTS OF THE INVENTION lt is an object of the invention to provide an artificial intraocular lens for obviating aphakia.

It is another object of the invention to provide an artificial intraocular lens for implantation into the posterior chamber of the eye.

It is a further object of the invention to provide an artificial intraocular lens which includes means for positioning it in the eye without irritation of sensitive portions thereof.

It is another object of the invention to provide an artificial intraocular lens which is easily implanted.

It is yet another object of the invention to provide means for holding the artificial intraocular lens during implantation thereof.

Other and more particular objects of the invention will be in part obvious and will in part appear from a perusal of the following description of the preferred embodiment and the claims, taken together with the drawings.

DRAWINGS FIG. l is a front elevation view partially in section, of an artificial intraocular lens according to the invention herein;

FIG. 2 is a side elevation view, partially in section, of the artificial intraocular lens of FIG. l;

FIG. 3 is a fragmentary sectional view of another embodiment of an artificial intraocular lens according to the invention herein;

FIG. 4 is a side elevation view of another embodiment of an artificial intraocular lens according to the invention herein;

FIG. 5 is a section view of the artificial intraocular lens of FIG. 4 taken along the lines 5--5 of FIG. 4;

FIG. 6 is a front elevation view of the artificial intraocular lens of FIG. l having an insertion collar according to the invention herein attached thereto;

FIG. 7 is a sectional view of the insertion collar handle taken along the lines 7-7 of FIG. 6;

FIG. 8 is a front elevation view of an alternative embodiment of an artificial intraocular lens having an insertion collar attached thereto according to the invention herein;

FIG. 9 is a sectional view of an eye showing an artificial intraocular lens according to the invention herein being implanted;

FIG. l0 is a sectional view of an eye showing an artificial intraocular lens according to the invention herein implanted therein;

FIG. 11 is a front view of an eye having an artificial intraocular lens according to the invention herein implanted therein;

FIG. 12 is a front view of an eye having another embodiment of an artificial intraocular lens according to the invention herein implanted therein; and

FIG. 13 is a front view of an eye having another embodiment of an artificial intraocular lens according to the invention herein implanted therein.

The same reference numbers refer to the same elements throughout the various figures.

PREFERRED EMBODIMENTS The invention herein relates to an artificial intraocular lens, several embodiments of which will be described, and an insertion necklace for holding and manipulating the artificial intraocular lenses during implantation thereof.

Referring now to FIGS. 1 and 2, there is shown an articial intraocular lens 10 according' to the invention herein. The lens l0 generally comprises an optical zone portion 11, a flange 12 peripherally surrounding the optical zone portion 1l, and a plurality of prongs 13-20 for anchoring the lens in an eye. A plurality of openings 21-24 may be provided through the flange near where the flange intersects the optical zone portion ll.

The optical zone portion ll can be either a biconvex or planoconvex lens, as required. It is preferable that the optical zone portion be shaped similar to the natural ocular lens insofar as is possible. The optical zone portion ll may have a diameter D of7 to 8 millimeters; however, this diameter is merely suggested and is approximately the same diameter as a natural ocular lens, and it should be recognized that the artificial intraocular lens can and should be sized according to the eye into which it is to be implanted. The power of the artificial intraocular lens generally should be in the range of 13 to 17 diopters with the final decision as to the exact power resting with the opthalmologic surgeon who has examined the patient.

The flange 12 peripherally surrounds the optical zone portion l1 along its outer edge and increases the overall diameter of the artificial intraocular lens l0 to approximately 9 to l0 millimeters. The flange 12 is provided to support the prongs 13-20, and more particularly is provided to permit mounting of the prongs spaced radially outwardly from the optical zone portion 11. The drain holes 21-24 are formed at the intersection of the flange l2 and the optical zone portion 11 and arrayed about the optical zone at 90 degree intervals. The drain holes provide for the free flow of aqueous humor from the ciliary body to the front of a lens and to the anterior chamber, as best seen in FIG. 10.

In the artificial intraocular lens 10, eight prongs 13-20 are arranged in four pairs arrayed about the periphery of the flange 12. Each prong extends forwardly from the flange 12 and is curved so that its outer end is disposed ,generally parallel to the plane of flange 12. Each prong is approximately 2 millimeters in length and its outer end is preferably enlarged and rounded. The base of each prong is positioned at the outermost periphery of flange l2, and the bases of each pair of prongs, such as prongs and 16, are separated by a distance S which may be approximately l millimeter. The prongs in each pair extend in opposite directions from each other along the outer periphery of flange 12. In the artificial intraocular lens l0 the prongs 13-20 are formed integrally with an annular band 25 which is seated in an outwardly opening peripheral groove 26 in flange l2.

The prongs 13-20 and the annular band 25 may be fabricated of gold or vitallium, or any other material having the desired qualities, which include being medically acceptable for implantation into the eye and also being sufficiently malleable or bendable to permit adjustment or manipulation and to eliminate risk of breakage. The optical zone portion l1 and the flange l2 are preferably fabricated of a medical grade of polymethyl methacrylate. The annular band 25 may be at least partially encapsulated in the flange 12 by molding the optical zone ll and flange 12 with the annular band 25 with the integral prongs 13-20 in position.

Referring now to FIG. 3, an intraocular lens 30 which is an alternative embodiment according to the invention herein is shown in a fragmentary view. The lens 30 is similar to the lens 10 except for the means of attaching the prongs thereto. ln lens 30, the prongs, such as prong 31, are attached to a peripheral flange 35 by inserting them into openings formed in the flange. An enlarged base portion 32 may be formed at the end of prong 31 to prevent it from pulling out of the opening. The prongs may be further secured to the flange by means of adhesive applied in the openings during the insertion of the prongs. Alternatively, the prongs may be encapsulated by properly positioning them during molding of the lens.

Referring now to FIGS. 4 and 5, there is shown an artificial intraocular lens 40 which is a third embodiment according to the invention herein. Lens 40 does not incorporate a peripheral flange, but is shaped similarly to the natural lens and has a plurality of pairs of prongs attached thereto near the periphery thereof. Although this embodiment does not permit spacing the prongs as far from the central portion of the lens as do the earlier described embodiments, the artificial intraocular lens 40 has the advantage of having no flange protruding outwardly therefrom which may come into contact with the ciliary body.

FIG. 5 illustrates the attachment of the prongs to the artificial intraocular lens 40. Two prongs 4l and 42 comprising one pair of prongs are integral by virtue of a connecting portion 43. The connecting portion 43 may be generally C-shaped and is capsulated in the lens during molding thereof. Alternatively, prongs could be attached to the lens 40 by forming the prongs integrally with an annular'band and seating the annular band in the outermost periphery of the lens, similar to the structure described above with respect to lens 10. The prongs could also be 'attached by forming opengings through or into the lens 40 and inserting the prongs therein, similar to the attachment of the prongs in lens 30 described above.

Because lens 40 does not incorporate a flange protruding radially outward therefrom, there is no need to provide drain holes for permitting the passage of aqueous about the edge of the lens.

The invention herein is also directed to an insertion necklace which aids the ophthalmologic surgeon in handling, inserting, and manipulating the artificial intraocular lens during implantation thereof. An insertion necklace according to the invention herein is indicated at 50 of FIG. 6, and it generally comprises a semirigid loop 5l having a tail 52 extending therefrom to a handle 53. Still referring to FIG. 6, the insertion necklace 50 is shown used with the artificial intraocular lens 10 of FIGS. 1 and 2. The loop 51 is passed through the drain holes 22 and 24 wherein a portion 51A of the loop embraces the backside of the optical portion 1 1 of the lens. The loop 51A is preferably sized so that the sections of the loop converging toward the tail 52 from drain holes 22 and 24 pass under the

prongs

17 and 18 respectively, wherein the prongs help to maintain the lens in the plane of the loop. The loop can be easily disengaged from the; prongs if and when desired.

Referring to FIG. 7, the handle 53 is preferably of an elongated oval or flat sectional configuration, wherein the lens may be easily twisted. The flat surface is preferably generall parallel to the front surface of the lens wherein the handle provides an indication of the orientation ofthe lens. The loop and tail are preferably fabricated of a semirigid material such as superamid or vitalli'um wire, or polyethylene or other plastic tubing or lwire, and the handle 53 into which the tail 52 is seated may be fabricated of the same material.

In FIG. 8 there is shown another artificial intraocular lens 60 constituting a fourth embodiment in the invention herein. The lens 60 is similar to the lens 10 described above except that the drain holes 61-64 of lens 60 are located between the tips of adjacent pairs of prongs rather than adjacent to the bases of each pair of prongs. The insertion necklace 50 is attached to the lens 60 with the loop 5l passed through drain holes 62 and 64. The sections of the loop l converging toward the tail 52 from drain holes 62 and 64 pass under prongs 65-66 and 67-68 respectively, and this arrangement provides for good engagement between the prongs and the converging sections of the loop 5l. However, this arrangement may not be preferred because it may be desirable to have one pair of prongs positioned at the forward edge of the artificial intraocular lens as it is being inserted, as shown in FIG. 6.

Referring now to FIGS. 9 and l0, there is shown an eye having an artificial intraocular lens according to the invention herein being implanted and implanted. The eye 70 comprises a transparent cornea 71 which connects with the sclera 72, better known as the white of the eye. The sclera extends substantially around the entire eye except for the region of the cornea. A thin membrane 73, which is known as the conjunctiva, extends from the cornea to the underside of the eyelid. Schlemns canal, indicated at 74, is located near the intersection of the cornea, sclera, and conjuctiva. In the rear portions of the eye, the choroid 75 overlays the interior surface of the sclera and the retina 76 overlays the inner surface of the choroid 75. Near the front of the eye the choroid joins with the ciliary body, genen ally indicated at 77, which includes the ciliary process 80 and ciliary muscle 8l. Extending fro'm the ciliary body is the iris 82 which defines the pupil 83. The choroid, ciliary body, and iris are together known as the uveal tract, which is a vascular tract surrounding most of the eye.

The interior of the eye is substantially filled with vitreous humor 90 and the hyloid membrane 91 covers the surface of the vitreous humor. The anterior chamber of the eye is indicated at 92, and is located between the front of the iris and the cornea 7l. The posterior chamber of the eye, indicated at 93, is located between the iris and the vitreous humor. The natural lens, not shown in the drawings herein, occupies the posterior chamber 93 and is held in place by zonules 94, which are shown cut as they would be during removal of the natural lens.

Referring now particularly to the iris 82, it defines the pupil 83 by virtue of a central opening therein. Sphincter and

dilator muscles

84 and 85 are located in the iris adjacent to the inner periphery thereof, and control the size of the pupil. The primary expansion and contraction of the tissue of the iris takes place in the vicinity near the sphincter and dilator muscles. The stroma 86 of the iris extends between the ciliary body and the inner portion of the iris including the sphincter and dilator muscles. The stroma tissue passively folds in an accordian-like manner during dilation and contraction of the pupil. The iris tissue, including the stroma, is quite flexible, and can be pulled and stretched. However, the iris has the unique property of not healing if torn or damaged. Accordingly, care should be taken in manipulating the iris.

Referring more specifically to FIG. 9, in order to implant an artificial intraocular lens according to the invention herein into the eye, the pupil is directly dilated to the point where the lens can be inserted therethrough without need for cutting the iris. Some stretching of the sphincter and dilator muscles is necessary to achieve passage of thev lens, but if carefully done these muscles will not be damaged.

An incision in the cornea is made near Schlemms ca nal, and the cornea is folded back. If implantation of an artificial intraocular lens is being undertaken because of a cataract condition, it is preferable to perform the natural lens removal and the implantation of the intraocular lens in the same operation. Accordingly, the first step after opening an incision and laying back the cornea may be to perform an intracapsular or extracapsular extraction, as the condition of the patient dictates.

Using the insertion necklace 50, the artificial intraocular lens 10 is inserted under one edge of the iris and the leading pair of prongs 13 (shown) and 14 (not shown) are pushed through the stroma tissue. Thereafter, the converging sections of loop 5l of the insertion necklace 50 may be disengaged from the anchoring prongs and the lens inserted entirely under the iris. The remaining prongs, such as

prongs

18, 19 and 20 (show) may now be inserted through the stroma, taking care to stretch the stroma tissue so that Ithe tip of each prong is inserted through the stroma tissue approximately at the point where the base of the anchoring prong will ultimately seat upon releasing the stroma.

After the lens has been firmly seated in the posterior chamber and the prongs have been inserted through the stroma of the iris, the loop 51 of the insertion necklace may be cut and the insertion necklace removed. The ophthalmologic surgeon may then close the eye in accordance with ordinary ophthalmologic surgical techniques.

Referring now particularly to FIG. l0, the artificial intraocular lens 10 is shown implanted into the eye 70. The artificial intraocular lens is positioned in the posterior chamber 93, thereby closely duplicating the natural state and providing for restoration of good binocular vision. The iris 82 is shown with the pupil 83 contracted to its normal position, whereby it is apparent that the prongs extend through the stroma portion of the iris, where they will cause no irritation. Also, because the stroma tissue passively folds and opens during dilation and contraction of the pupil, the lens does not cause pulling or tearing of the iris and remains in its proper position.

It should also be noted that the artificial intraocular lens, and specifically the flange thereof, is spaced well away from the ciliary body, and thereby will not cause irritation thereof. The ciliary body may contract somewhat as the ciliary muscles 8l atrophy, enhancing the separation from the implanted lens. Also, the drain holes are positioned to insure free flow of aqueous produced by the ciliary body to the front portion of the lens under the iris and to the anterior chamber, even if the edge portion of the lens should contact the iris.

The artificial intraocular lens also provides support for the hyloid membrane and the vitreous humor. It is anticipated that fewer instances of retinal detachment will follow cataract surgery when using an artificial intraocular lens according to the invention herein.

Procedure for implantation of the other embodiments of artificial intraocular lenses according to the invention herein is similar. The position of the other lenses in the eye after implantation isalso similar, i.e.,

the lenses are positioned in the posterior chamber of the eye with the prongs extending forwardly through the stroma of the iris.

Referring now to FIG. 11, a front view of the eye 70 having the artificial intraocular lens l implanted therein is shown. lt will be noted that the prongs 13-20 protrude through the iris 82 in its outer or stroma portion 86 and hold the lens in position without interfering with dilaton of the pupil. The optical zone portion ll of the lens is positioned behind the pupil 83, as desired.

Referring now to FIG. l2, there is shown an eye 100 having an iris 101 upon which a peripheral iridectomy has been performed to obviate glaucoma, in accordance with ordinary techniques. Therefore, the iris 101 has the usual pupil 102 positioned at the center thereof, and in addition has a secondary, peripherally positioned pupil 103 resulting from the peripheral iridectomy. Another embodiment 110 of an artificial intraocular lens according to the invention herein has been implanted into the eye 100. The lens 110 is ccharacterized by having prongs lll-116 arranged in three pairs evenly spaced about its periphery. Three pairs of prongs are sufficient to hold the lens in position and are easily placed to not interfere with the secondary pupil 103 formed during the peripheral iridectomy.

Another eye 120 is shown in FIG. 13 wherein a sector iridectomy has been performed on the iris 121 thereof to enlarge the pupil 122 so that it extends to the periphery of the iris. An artificial intraocular lens 125 comprising another embodiment of the invention herein has been implanted into the eye 120. The lens 125 has six prongs 126-131 arranged in three pairs spaced about the periphery of the lens; however, in contrast to the earlier described embodiments,

prongs

126 and 127 comprising the first pair of prongs have their bases widely separated to straddle and accommodate the elongated pupil 122 therebetween. The remaining prongs 128-131 are arranged in two pairs substantially evenly spaced with the first pair of prongs about the periphery of the lens 125.

FIGS. l2 and 13 illustrate how the artificial intraocular lens according to the invention herein may be adapted for use in a variety of medical situations, such as the peripheral iridectomy and the sector iridectomy.

It will be apparent to those skilled in the art that various modifications of the artificial intraocular lenses described herein can be made without departing from the spirit and scope of the invention. For instance, the number of prongs and the precise positioning of the prongs may be altered, and similarly, the number of drain holes and their positions can be altered. Other materials may be suitable for fabricating artificial intraocular lenses according to the invention herein, and the materials disclosed herein merely provide acceptable examples. The sizes of the artificial intraocular lenses may be changed, particularly when the lenses are to be used in animals. Also, other means for holding and manipulating the lenses may be employed. For instance, the artificial intraocular lenses can be held and manipulated by conventional forceps, or by provision of a flexible tipped instrument having an opening therethrough to which suction is applied, wherein the lens is held to the instrument by vacuum and released from the instrument by releasing the section. With respect to the technique of implanting the artificial intraocular lenses described herein, various ophthalmologic surgeons may develop different techniques dictated by their own skills and preferences.

The artificial intraocular lenses and the apparatus aiding implantation thereof described above are believed to efficiently achieve the objects of the inven tion. The usefulness and advantages of the artificial intraocular lenses and the apparatus aiding implantation thereof will be readily apparent to those skilled in the art.

Accordingly, the above description of the preferred embodiments is to be construed as illustrative only rather than as limiting, and the scope of the invention is defined in the following claims.

I claim:

1. An artificial intraocular lens for implantation in the posterior chamber of an eye, the artificial intraocular lens comprising an optical zone portion fabricated of transparent material and shaped similar to a natural lens, and a plurality of prongs attached to the optical zone portion near the periphery thereof, the prongs protruding forwardly therefrom for insertion through the iris of the eye to hold and position the lens therein.

2. An artificial intraocular lens as defined in claim l and further comprising a groove formed in the outer periphery of the optical zone portion and an annular band formed integrally with the prongs, the annular band matingly received in the groove whereby the prongs are attached to the optical zone portion.

3. An artificial intraocular lens as defined in claim 1 and further comprising openings formed in the optical zone portion near the periphery thereof wherein the prongs are tightly received and held in the openings and are thereby attached to the optical zone portion.

4. An artificial intraocular lens as defined in claim 1 wherein the inner portions of the prongs adjacent to the optical zone portion protrude forwardly from the optical zone portion and wherein the prongs are curved so that the outer portions of the prongs extend along the periphery of the optical zone portionand generally parallel to the plane of the periphery of the optical zone portion.

5. An artificial intraocular lens as defined in claim 4 wherein the plurality of prongs is an even number of prongs arranged in pairs about the outer periphery of the optical zone portion, each pair of prongs comprising two prongs attached to the optical zone portion at adjacent points, and wherein the outer portions of the prongs in each pair of prongs extend in opposite directions along the periphery of the optical zone portion.

6. An artificial intraocular lens as defined in claim 1 wherein the inner portions of the prongs adjacent to the optical zone portion protrude forwardly from the optical zone portion and wherein the prongs are curved so that the outer portions of the prongs extend along the periphery of the optical zone portion.

7. An artificial intraocular lens as defined in claim 6 wherein the plurality of prongs is an even number of prongs arranged in pairs about the outer periphery of the optical zone portion each pair of prongs comprising two prongs attached to the optical zone portion at adjacent points, and wherein the outer portions of the prongs in each pair of prongs extend in opposite directions along the periphery of the optical zone portion.

A8. An artificial intraocular lens as defined in claim 7 wherein the plurality of prongs comprises eight prongs arranged in four pairs.

9. An artificial intraocular lens as defined in claim l wherein the plurality of prongs is an even number of prongs arranged in pairs about the outer periphery of the optical zone portion, eachpair of prongs comprising two prongs attached to the optical zone portion at adjacent points.

l0. An artificial intraocular lens as defined in claim 9 wherein each pair of prongs is integral by virtue of a connecting portion extending therebetween and wherein the prongs are mounted by imbedding the connecting portion in the optical zone portion.

1l. An artificial intraocular lens as defined in claim 9 wherein the pairs of prongs are evenly spaced about the periphery of the optical zone portion.

l2. An artificial intraocular lens for implantation in the posterior chamber of an eye, the artificial intraocular lens comprising an optical zone portion fabricated of transparent material and shaped similar to a natural lens, a flange formed integrally with the optical zone portion and extending radially outwardly from the periphery of the optical zone portion, and a plurality of prongs attached to the flange, the prongs protruding forwardly therefrom for insertion through the iris of the eye to hold and position the lens therein.

13. An artificial intraocular lens as defined in claim 12 and further comprising a groove formed in the outer periphery of the flange and an annular band formed integrally with the prongs, the annular band matingly received in the groove whereby the prongs are attached to the flange.

14. An artificial intraocular lens as defined in claim l2 and further comprising openings formed in the flange near the periphery thereof wherein the prongs are tightly received and held in theopenings and are thereby attached to the flange.

15. An artificial intraocular lens as defined in claim l2 wherein the plurality of prongs is an even number of prongs arranged in pairs about the outer periphery t)f wtlregflarg eh pair of prongswgmprising two` prongs attached to the flagemat'jacent`points"/"" 16. An artificial intraocular lens as defined in claim l5 wherein each pair of prongs is integral by virtue of a connecting portion extending therebetween and wherein the prongs are mounted by imbedding the connecting portion in the flange.

17. An artificial intraocular lens as defined in claim 12 wherein the inner portions of the prongs adjacent to the flange protrude forwardly from the flange and wherein the prongs are curved so that the outer portions of the prongs extend along the periphery of the flange and generally parallel to the plane of the flange.

18. An artificial intraocular lens as defined in claim 17 wherein the plurality of prongs is an even number of prongs arranged in pairs above the flange, each pair of prongs comprising two prongs attached to the flange at adjacent points, and wherein the outer portions of the prongs in each pair of prongs extend in opposite directions along the periphery of the flange.

19. An artificial intraocular lens as defined in claim 12 wherein the inner portions of the prongs adjacent to the flange protrude forwardly from the flange and wherein the vprongs are curved so that the outer portions of the prongs extend along the periphery of the flange.

20. An artificial intraocular lens as defined in claim 19 wherein the plurality of' prongs is an even number of prongs arranged in pairs about the flange, each pair of prongs comprising two prongs attached to the flange at adjacent points, and wherein the outer portions of the prongs in each pair of prongs extend in opposite directions along the periphery of the flange.-

2l. An artificial intraocular lens as defined in claim 20 wherein the plurality of prongs comprises eight prongs arranged in four pairs.

22. An artificial intraocular lens as defined in claim 20 wherein the pairs of prongs are evenly spaced about the periphery of the flange.

23. An artificial intraocular lens as defined in claim 22 and further comprising a plurality of drain holes extending through the artificial intraocular lens near the intersection of the flange and the optical lzone portion thereof, wherein a drain hole is positioned adjacent to the inner portions of each pair of prongs.

24. An artificial intraocular lens as defined in claim 12 and further comprising a plurality of drain holes extending through the artificial intraocular lens near the intersection of the flange and the optical zone portion thereof.

25. An artificial intraocular lens as defined in claim 24 wherein the plurality of drain holes are evenly spaced about the periphery of the optical zone portion.

26. An artificial intraocular lens as defined in claim 24 and further comprising an insertion necklace for holding and manipulating the artificial intraocular lens during the implantation thereof, the insertion necklace comprising a loop and a handle, the loop passing through two of the drain holes in the artificial intraocular lens wherein one portion of the loop embraces the rear surface of the optical zone portion and another portion of the loop extends to the handle.

27. An artificial intraocular lens as defined in claim 26 wherein the portion of the loop of the insertion necklace extending to the handle removeably engages at least one of the prongs.

28. An artificial intraocular lens as defined in claim 26 wherein the drain holes through which the loop passes are located substantially opposite from each other about the periphery of the optical zone portion. a:

Claims

2. An artificial intraocular lens as defined in claim 1 and further comprising a groove formed in the outer periphery of the optical zone portion and an annular band formed integrally with the prongs, the annular band matingly received in the groove whereby the prongs are attached to the optical zone portion.

4. An artificial intraocular lens as defined in claim 1 wherein the inner portions of the prongs adjacent to the optical zone portion protrude forwardly from the optical zone portion and wherein the prongs are curved so that the outer portions of the prongs extend along the periphery of the optical zone portion and generally parallel to the plane of the periphery of the optical zone portion.

7. An artificial intraocular lens as defined in claim 6 wherein the plurality of prongs is an even number of prongs arranged in pairs about the outer periphery of the optical zone portion,, each pair of prongs comprising two prongs attached to the optical zone portion at adjacent points, and wherein the outer portions of the prongs in each pair of prongs extend in opposite directions along the periphery of the optical zone portion.

8. An artificial intraocular lens as defined in claim 7 wherein the plurality of prongs comprises eight prongs arranged in four pairs.

9. An artificial intraocular lens as defined in claim 1 wherein the plurality of prongs is an even number of prongs arranged in pairs about the outer periphery of the optical zone portion, each pair of prongs comprising two prongs attached to the optical zone portion at adjacent points.

10. An artificial intraocular lens as defined in claim 9 wherein each pair of prongs is integral by virtue of a connecting portion extending therebetween and wherein the prongs are mounted by imbedding the connecting portion in the optical zone portion.

11. An artificial intraocular lens as defined in claim 9 wherein the pairs of prongs are evenly spaced about the periphery of the optical zone portion.

12. An artificial intraocular lens for implantation in the posterior chamber of an eye, the artificial intraocular lens comprising an optical zone portion fabricated of transparent material and shaped similar to a natural lens, a flange formed integrally with the optical zone portion and extending radially outwardly from the periphery of the optical zone portion, and a plurality of prongs attached to the flange, the prongs protruding forwardly therefrom for insertion through the iris of the eye to hold and position the lens therein.

14. An artificial intraocular lens as defined in claim 12 and further comprising openings formed in the flange near the periphery thereof wherein the prongs are tightly received and held in the openings and are thereby attached to the flange.

15. An artificial intraocular lens as defined in claim 12 wherein the plurality of prongs is an even number of prongs arranged in pairs about the outer periphery of the flange, each paif of prongs comprising two prongs attached to the flange at adjacent points.

16. An artificial intraocular lens as defined in claim 15 wherein each pair of prongs is integral by virtue of a connecting portion extending therebetween and wherein the prongs are mounted by imbedding the connecting portion in the flange.

19. An artificial intraocular lens as defined in claim 12 wherein the inner portions of the prongs adjacent to the flange protrude forwardly from the flange and wherein the prongs are curved so that the outer portions of the prongs extend along the periphery of the flange.

20. An artificial intraocular lens as defined in claim 19 wherein the plurality of prongs is an even number of prongs arranged in pairs about the flange, each pair of prongs comprising two prongs attached to the flange at adjacent points, and wherein the outer portions of the prongs in each pair of prongs extend in opposite directions along the peripherY of the flange.

21. An artificial intraocular lens as defined in claim 20 wherein the plurality of prongs comprises eight prongs arranged in four pairs.

23. An artificial intraocular lens as defined in claim 22 and further comprising a plurality of drain holes extending through the artificial intraocular lens near the intersection of the flange and the optical zone portion thereof, wherein a drain hole is positioned adjacent to the inner portions of each pair of prongs.

28. An artificial intraocular lens as defined in claim 26 wherein the drain holes through which the loop passes are located substantially opposite from each other about the periphery of the optical zone portion.