CA1163401A

CA1163401A - Intraocular lens

Info

Publication number: CA1163401A
Application number: CA000355271A
Authority: CA
Inventors: John H. Sheets
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-08-30
Filing date: 1980-07-03
Publication date: 1984-03-13
Also published as: US4328595A; JPS5634344A; GB2057270B; FR2464063B1; NL180906B; DE3032144A1; IT8049466A0; FR2464063A1; NL8004782A; JPS6051905B2; AU5962080A; GB2057270A; NL180906C; IT1127871B; AU531073B2; DE3032144C2

Abstract

ABSTRACT

An intraocular lens assembly for positioning in the posterior chamber of the eye has a plastic lens body supported in the eye by first and second flexible spring-like resilient support loops of circular cross-section extending symmetrically from opposite sides of the peripheral edge of the lens body, the outer end of each support loop is received in and biased against the equatorial region of the lens capsule of the eye from which the natural lens has been removed and has first and second outwardly protruding arcuate contact feet engaging the capsule and separated by an inwardly extending arcuate connector portion with first and second support legs extending from the opposite ends of the contact feet to chordal openings in the periphery of the lens body in which the inner ends of the support legs are fixedly embedded.

Description

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j, B~CXGROUND OF THE INVENTION
.1i . l ¦ This invention is in the field of intraoeular lenses for correetion of aphakia by implantation in the posterior ehamber of the human eye. More speeifieally, the present invention is directed to an intraocular lens for self-centered non-sutured, positioning in the lens capsule of the human eye following extracapsular removal of the natural lens therefrom.
It has long been reco~nized and accepted that an intraocular lens implanted in the human eye ollowing eataract sur~ery will provide substantially better vision than is possible with the use of either o the available -alternatives of contaet lens or spectacles. I~owever, while the first intraocular lens implantations were begun by Dr.
?darold Ridley in 19~9, whc impianted a plastic lens in the posterior ehamber following an ex-tracapsular càtaract extraction, there were a large percentage of complications such as iritis, pupillary occlusion, dislocation of the lens and the like which prevented general acceptance of intraocular lens implantation. -~ wide ~ariety of lens constructions and surgical techniques subse~ eiltly evolved as the result of efforts to overcome the problems of the original P~idley lens. Generally speaking, the majority of subsequent efforts were directed toward the provision of a lens for implantation in tha anterior chamber o the eye due primarily to the easier acce~sibility o the anterior chamber and the fact that the lens could be easily positioned by the sur~eon in a manner not possible with a posterior chamber mounted lens. Earlier .1 .
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, anterior chamber lenses were suppor-ted by contact with the anterior chamber angle and also frequen-tly contacted the cornea.
Entirely satisfactory results were not always achieved with the more frequent complications including corneal dystrophy resultant`from endothelial contact, corneal edema, and inherent optical inadequacy in not providin~ full binocular vision and optical malfunction due to mispositioning. Subsequent anterior chamber positioning was achieved by fixation to the iris with the most successful lens of this general typ~ being that of B~nkhorst employing rigid posterior chamber loops extending through the pupil to the anterior chamber positioned lens. Unfortunately, erosion of the iris sometimes results with these and other iris contacting or attached lenses.
Other previously proposed lens attachment and mounting means have included rigid loops, arms, plates, legs and the like which have been held in place by sutures, such as exemplified by the rigid loops 12 and 13 in Jensen Patent No. 4,110,848 and by rigid plates 12 and 13 of Kelman Patent No. 4,092,743, with the sutures extending through the iris. Prongs 13 etc.
~0 e~tending through the iris are disclosed in the Flom Patent No. 3,866,249. Jensen Patent No. 3,994,027 and Peyman Patent No. 4,073,015 both disclose rigid support loops engaging the anterior capsule wall.
Iris engaging clip support for a posterior lens is shown in Richards et al Patent No. 4,014,049. In many instances, the lens body itself also contacts the iris and in the case of the majority of posterior chamber implants, the lens body contacts or exerts pressure on the ciliary :`` `

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l body in the manner of the original ~idley lens and as more ,! recently exempli~ied in the aforementioned Richards et al I patent and Potthast Patent No. 3 913 148 so as to create the i possibility of tissue necrosis.
1 Another recent posterior chambex lens is disclosed in Shearing Patent No. 4,159 546 in which J-shaped elastic support members extend outwardly from opposite peripheral edges of the lens to ensage the ciliary body, or possibly ¦ the lens capsule r to support the lens in position. Unfortunatel~ r l the J-shaped support members do not have substantial resistance to torsional twisting and flexing and it is consequently difficult to accurately and predictably position the lens and its support members in the posterlor chamber.
It has also been proposed by Grinder to employ flexible capsule engaging support loops of a shape similar to element 12 of the ~elman Patent No. 4 092,743 with two of such loops e~tellding from opposite sides of the lens body.
For a more extensive treatment of prior known intraocular lenses refe}ence is also made to my prior publications Bridge ~0 Over Troubled Waters and Covered Bridge.
Notwiths-tanding the great strides made in lens im-plantation since the original Ridley ac-tivity as evidanced by the 'housands of successful lens implantations, complica-tion; in individual cases continue to arlse in a small percentage of the cases. In addition to -the previously noted corneal and other problems, unsatisfactory results can arise from the lens becoming misposi-tioned for a variety of reasons such as erosion of the iris or t:he ciliary body portion of the eye with which the support and posLtioning elemc3llts are encJ.Iged. Improper sizing and excessive weight of the lens an~ support elements also causes subsequent mispositioning of -the lens in some instances. It i3 consequentl~
desirable to avoid the use oE sutures and other similar - 11 . " , " .

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! connectors engaging viable portions of the eye and to minimize contact of the lens and its support means with the iris and ciliary body to the fullest extent possible. .
SUM~ARY OF THE INVENTION
¦ Thus, it is the primary object of this invention to I provide a new and improved intraocular lens.
¦ A further object of this invention is the provision of I a new and improved intraocular lens for posterior chamber !l implantation supported by the lens capsule.
Achievement of the ~oregoing objects is enabled by the . preferred embodiment of the present invention which comprises . a lens body havinq first and second spring-like 4~
support. loops extending outwardly in a symmetrical manner ~rom opposite sides of the periphery of the lens body for en~agement with the equatorial region of the lens capsule in the area of the juncture of the anterior and posterior capsule walls. Each of the support loops is formed of a flexible unitary spring-like material such as polypropylene with each loop having its outer extent defined by first and second arcuately curved contact feet separated by an inwardly extending arcuate connector portion wi-th the ooposite sides of the contact feet being respectively unitarily connec-ted to irst ancl second leq components extending to the lens body.
The first and second leg components diverge outwardly from the lens and are oriented so that the first contact foot will .in most instances enqage the equatorial regiol- of the lens 99 ~ ¦ capsulo with lcss force than will the ~r-s-t~lcontact footO
.'~he inncr ends of the leg members are connected to the lens . ~y convelltional bonding techniques. The locations of the ~ , _5_ .

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inner ends are such that ~he cho~ds formed kY an imaginary extension of the leg members are separated by approxlm~a-tely 27 The arran~ement is such that t~e lens is easily and automatically accurately positioned within the lens capsule of the eye verticallyr horizontally and rotationally simply by t~e sprin~
action of the support loop~ in contact with the interior surface of the lens capsule~ There is normally no need to effect suturing of the support means to any p~rt~on of the eye and~
there is ordinarily an absence. of cont.act with t~e ci~inar~
body. Since the lens capsule is ormed of: firm, ess~ntia~lly non-viable tissue, inflammation, trauma and erosion are substantially less likely to occur than ~s the case w~i~h prior art devices supported by or co~tacting t~e ciliary bod~ ~nd/or the iris or using rigid plates or other ~ypes of~ loops contacting the capsule~ Since e~ch SUppQX`~ loop prov~i~es two :
spaced contact foot areas of capsu~e contact, a total of four contact support areas serve to engage the capsule to provide a secure and reliable support for th~ lens bodyO
Briefly, therefore, the in~ention comprises an intraocular lens assembly for se~f~ce~tered positioning in the lens capsule of the eye comprising a lens body, first and second support members extending from the lens body for ~ngaging the lens capsule. At least one of the support members comprises ~ spring-like flexible suppor:~ loop e~tending outwardly from the lens body and includ~es firs~ and second end porti:ons attached to the lens body at first and second attachment locations. A first contact foot portio~ is positioned ~o engage one area of the lens capsule with an outward radial force cr/~

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A better understanding of the manner in which the preferred embodiment achieves the objects of the invention will be enabled when the following detailed description is considered in conjunction with the appended drawings in which like reference numerals are employed in the different figures for identification of the same component parts of the preferred embodiment.

BRIEF DESCRIP~ION OF THE DRAWINGS

_ Figure 1 is a front elevation view of the preferred embodiment of the invention;
Figure 2 is a side elevation view of the preferred embodiment;

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,¦ Figure 3 is a front elevation view of the preferred embodiment as implanted in the eye with portions removed for .¦
, clarity of illustration; and Fiqure 4 is a bisecting sectional view of the eye of ~I Figure 3 with the lens in implanted position, !i DESCRIP~ION OF T~IE PREFERRED EMBODIMENT
The preferred embodiment 5 of the invention basically l~¦ consists of a molded lens body 6 formed of optical plastic Il such as polymethylmethacrylate. The lens body 6 of 4mm to ~ 6mm diameter is provided with a planar posterior face 7, a cylindrical peripheral surface 8 and a spherical anterior face 9 of desired curvature to give the required optical -charactcristics for the particular patient in which it is to be implanted. Support and retention o~ -the lens body 6 is 15 ¦ provided by a flrst spring-like sùpport loop 12 and a second spring-like support loop 14 with the support loops being fo~ed of circular cross-section polypropylene or other similar flexible nmaterial of approximately 0.15mm diameter.
Loops 12 and 14 are preferably positioned in a con~on plane ~?.0 pcrpendicular to and symmetrically wi-th respect to the " optical and geometric axis 16 of the lens body ~ ~ with the outcrmost portions of the respective loops wllen in their rela~ecl condition of ~igures 1 and 2 being approximately 12mm apart. In some instances, it might be desirable to cant the loc,ps with respect to the ]ens axis.
The first and second support loops are in the form of identical configuration with each including a first contact foot portion ~0 and a second contact foot portion 22 with 11 , , :

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' each foot portion being o~ arcuate axial configuration ~¦ having a center of curvature be~ween it and the lens body 6 . as will be apparent from inspection of Figure 1. The arcuate Il extent of the first contact foot 20 is less than 180 while 5 ¦¦ the arcuate extent of the second contact foot 22 exceeds I¦ 180. Contact foot portions 20 and 22 are connected by an ! inwardly extending oppositely curved arcuate connector .¦ portion 24 which has a center of curvature positioned jll outwardly from itself with respect to the lens body 6. It j, should also be observed that the second contact foot portion !i 22 is positioned radially outwardly a greater distance from the lens body 6 than is the first contact foot portion 20 so that wllen the lens is positioned within the capsular membrane, I second contact foot portion 22 engages the membrane with ! slightly greater force than does the first contact foot portion 20 when positioned in a normally sized lens capsule;
however, in some instances where the capsule is smaller, the .
first contact foot 20.can engage the capsule with greater . force than second contact Eoot 22. Inward movement of second contact foot 22 as a result of positioning of -the loops 12 and 1~ in the capsule as in Figure 3 brings the curved connector portion 2~ into closer proximity with the second support leg 32 than is the case when the loops ara in their relaxed condition of ~igure lo ~dditionally, each of the support loops includes a ~irst support leg 30 of linear conEiguration and a second ¦ ~upport le~ 32 oE arcuate configuration. Support legs 30 nd 33 dive ge out~ardly from the eriphery 3 of th~ lens 1, ~ .

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~, body 6 and are respectively connected to first and second ¦¦ end portions 34 and 36 of the loops chordally positioned ¦, inside the lens body and bonded thereto by a heat probe or .¦
~,' 11 u~trasonic probe in a conventional mannerO
1I Preparation of the eye for receipt of the preferred i em~odiment is effected by a conventional extracapsular Il cataract removal procedure in which the central portion of ¦¦ the anterior wall 3~ of the lens capsule is removed along Il with the natural lens so as to leave the equatorial region ¦¦ 40 and posterior wall 42 of the lens capsule in position as . shown in Figure 4.
Thus, when the preferred embodiment 5 is positioned in the eye as shown in the drawings, there is basically a four-point support for the lens which resists rotation and other lel~s movement with the e~-ast-i~ spr~ng-like nature of the support loops serving to center the lens with respect to the optic axis of the eve in a position closely corresponding with the position of the original natural lens as shown in Figure 3. There is some deflection of the equatorial region 40 of the lens capsule and the main contact therewith . of each loop is at contact foot portions 20 and 22 wi-th some mt~dial contact along the connector portion 24 depending on the extent to ~hich the lens capsule is deflected by the portions 20 and 22. Since foo-t portion 22 engages the lens capsule with grcater :Eorce than foot portion 20, except in ràro cases t~here the capsule is unusually small, the area of the lens capsule engaged hy portion 22 is deflected radially outwardly a greater distance than the area engaged by foot portion 20. There is no contact with the iris or any otller I ' .. .~ .. . .. ....... .... .....
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i easily injured vascular eye component with all contact being between the support loops 12 and l~ and the relatively tough non-traumatic avascular tissue of the lens capsule. ~here Il is an absolute and complete lack of any need for sutures, ¦I clamps, prongs or the like for retaining the lens in positionO
By employing capsular fixation, there is little chance of pseudophacodenesis. The ciliary body 70 and iris 80 are not contacted with any substantial force by the lens or loops and the likelihood of damage tc either is consequently avoided.
In addition to the foregoing, the present invention by using relatively small loops provides substantial advantages over the prior art in that it can be positioned in the eye through a relatively small inverted V-shaped incision in the anterior wall of the capsule. Since the support loops do ¦ not have to e~tend radially outwardly -to the area of the ciliary body, they can consequently be substantially smaller than is the case with lens such as the Shearing lens in which support members are engaged with the ciliary body. In 0 ¦ addition to enabling an easier positioning in the eye, the present invention is also consec~uently easier to remove in ¦ the event re.noval is required. Additiona]ly, the present invention permits the use oE a single plane lens so as to substan(:ially reduce the chance of damage to the corneal 5 ¦ ~ndotllelium. The fle~ible nature of the loops permits the use of a single size for all eyes to provide a distinct advankagc over rigid loops, plates and the li~e previously employcd for lens support. Connection of the support loops to tl e lens at bot~ end. provldes sut~icient re5is tanc,~ to 1~ -10--; .

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twisting deflection of the loops to ensure substantially easier and more accurate positioning in the eye than is possible with the J-shaped support system of Shearing.
It should also be noted that there is a good chance of the obtainment of satisfactory results even in circumstances in which the present invention is improperly positioned in the eye such as, for example, with one of the contact feet being out of the capsule.
Further, since there is no contact with the ~ris, complete dilation of the eye is possible and it is easy for the doctor to do subsequent ophthalmoscopy.
Numerous modifications of the preferred embodiment will undoubtedly occur to those of skill in the art, for example, the lens body and loops could be formed unitari~y.
It should be understood that the spirit and scope of the ~
invention is not limited to the preferred embodiment but is to be limitedsolely by the appended claims.

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Claims

I CLAIM:

1. An intraocular lens assembly for SELF-CENTERED
positioning in the lens capsule of the eye comprising a lens body, first and second support members extending from the lens body for engaging the lens capsule, at least one of said support members comprising a spring-like flexible support loop extending outwardly from said lens body and including first and second end portions attached to the lens body at first and second attachment locations, a first contact foot portion positioned to engage one area of the lens capsule with an outward radial force and a second contact foot portion spaced from the first contact foot portion to engage a second area of the lens capsule with an outward radial force.

2. The lens assembly of claim 1 wherein said support loop includes an inwardly extending connector portion positioned inwardly of and between the first contact foot portion and the second contact foot portion.

3. The lens assembly of claim 2 wherein said support loop further includes a first support leg extending between the first end portion and the first contact foot portion and a second support leg extending between the second end portion said the second contact foot portion.

4. The lens assembly of claim 3 wherein the first and second end portions of said support loop extend inwardly from the peripheral edge of the lens body in linear chordal orientation with respect to the lens body.

5. The lens assembly of claim 2 wherein said first and second support loops are positioned on said lens body in symmetrical relationship to each other with each support loop further including first and second outwardly diverging support legs respectively connected to said first contact foot portion and said second contact foot portion on their outer ends and to said first and second end portions on their inner ends. .'

6. An intraocular lens assembly for self-centered positioning in the lens capsule of the eye comprising a lens body, first and second spring-like flexible support loops extending outwardly from said lens body, each of said support loops including first and second end portions attached to the lens body at first and second attachment locations, a first contact foot portion positioned to engage one area of the lens capsule with an outward radial force and a second contact foot portion spaced from the first contact foot portion to engage a second area of the lens capsule with an outward radial force.

7. The lens assembly of claim 6 wherein each of said support loops includes an inwardly extending connector portion positioned inwardly of and between the first contact foot portion and the second contact foot portion.

8. The lens assembly of claim 7 wherein each of said support loops further includes a first support leg extending between the first end portion and the first contact foot portion and a second support leg extending between the second end portion and the second contact foot portion.

9. The lens assembly of claim 8 wherein the first and second end portions of each support loop extend inwardly from the peripheral edge of the lens body in linear chordal orientation with respect to the lens body.

10. The lens assembly of claim 7 wherein said first and second support loops are positioned on said lens body in symmetrical relationship to each other with each support loop further including first and second outwardly diverging support legs respectively connected to said first contact foot portion and said second contact foot portion on their outer ends and to said first and second end portions on their inner ends. .

11. The lens assembly of claim 10 wherein the first and second end portions of each support loop extend inwardly from the peripheral edge of the lens body in linear chordal orientation with respect to the lens body.

12. The lens assembly of claim 10 wherein said first contact foot portion and said second contact foot portion are of arcuate curved configuration each having a center of curvature positioned between such contact foot portion and said lens body.

13. The lens assembly of claim 10 wherein said first support leg is normally of linear configuration and said second support leg is normally of curved configuration and curves outwardly away from the first support leg.

14. The lens assembly of claim 6 wherein each of said support loops includes an inwardly extending connector portion positioned inwardly of and between the first contact foot portion and the second contact foot portion and said second contact foot portion is normally positioned when in a relaxed state a greater radial distance from the axis of the lens body than is said first contact foot portion.

15. The lens assembly of claim 14 wherein each of said support loops further includes a first support leg extending between the first end portion and the first contact foot portion and a second support leg extending between -the second end portion and -the second contact foot portion.

16. The lens assembly of claim 15 wherein the first and second end portions of each support loop extend inwardly from the peripheral edge of the lens body in linear chordal orientation with respect to the lens body.

17. The lens assembly of claim 16 wherein said first contact foot portion, said second contact foot portion and said connector portion are of curved configuration with each of said contact foot portions having a center of curvature positioned between such contact foot portion and said lens body.

18. The lens assembly of claim 17 wherein said first support leg is normally of linear configuration and said second support leg is normally of curved configuration and curves outwardly away from the first support leg.

19. The lens assembly of claim 6 wherein said support loops are positioned in a common plane perpendicular to the axis of said lens body.

20. The lens assembly of claim 19 wherein each of said support loops includes an inwardly extending connector portion positioned inwardly of and between the first contact foot portion and the second contact foot portion.

21. The lens assembly of claim 20 wherein each of said support loops further includes a first support leg extending between the first end portion and the first contact foot portion and a second support leg extending between the second end portion and the second contact foot portion.

22. The lens assembly of claim 21 wherein the first and second end portions of each support loop extend inwardly from the peripheral edge of the lens body in linear chordal orientation with respect to the lens body.

23. The lens assembly of claim 19 wherein each of said support loops includes an inwardly extending connector portion positioned inwardly of and between the first contact foot portion and the second contact foot portion and said second contact foot portion is normally positioned a greater radial distance from the axis of the lens body than is said first contact foot portion.

24. The lens assembly of claim 23 wherein each of said support loops further includes a first support leg extending between the first end portion and the first contact foot portion and a second support leg extending between the second end portion and the second contact foot portion.

25. The lens assembly of claim 24 wherein the first and second end portions of each support loop extend inwardly from the peripheral edge of the lens body in linear chordal orientation with respect to the lens body.

26. The lens assembly of claim 25 wherein said first contact foot portion, said second contact foot portion and said connector portion are of curved configuration with each of said contact foot portions having a center of curvature positioned between such contact foot portion and said lens body.