CA1164602A

CA1164602A - Posterior chamber intraocular lens

Info

Publication number: CA1164602A
Application number: CA000390305A
Authority: CA
Inventors: Gerald D. Faulkner
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-12-01
Filing date: 1981-11-18
Publication date: 1984-04-03
Also published as: AU7748581A; IN157374B; JPS5848182B2; JPS57142249A; EP0053384B1; DE3175233D1; US4366582A; EP0053384A1; AU559274B2

Abstract

TITLE: Posterior Chamber Intraocular Lens INVENTOR: Gerald D. Faulkner ABSTRACT OF THE DISCLOSURE

A lens for implantation in the posterior chamber of the eye is provided with a structure which engages the anterior surface of the iris to retain the lens against posterior dis-placement within the eye. The lens may be utilized even if the capsule is missing or damaged.

Description

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1 BACKGROUND OF THE_INVENTION

The present invention relates to an intraocular lens for use as a replacement for the natural lens of a human eye.
As an aid in understanding the present invention, back-ground discussion will be given. As illustrated in Fig. l, a sectional view of a normal eye, the wall 20 of the eyeball has a clear anterior or front portion 22, known as the cornea.
IlThe iris 24, a colored annular`structure, is disposed posteriorly I~of cornea 22. The space 25 in front of the iris and behind the cornea is referred to as the anterior chamber. Iris 24 defines ! a hole or pupil 26 aligned with cornea 22 on the anterior-,posterior Ifront to back~ axis 28 of the eyeball. A clear, ,Igelatinous substance known as vitreous is disposed in a cavity ~, 29 posterior of the iris. A lens 30 including a nucleus 31 and a cortex 32 is disposed in the posterior chamber 33, the ,space between vitreous cavity 29 and iris 24. The lens is ~surrounded by a capsule consisting of the anter1or capsule 34, I,a clear me~brane overlying the anterior surface of lens 33, ,land the posterior capsule 35, a clear membrane overlying the ;posterior surface of lens 33, with posterior capsule 35 confronting vitreous cavity 29. Anterior capsule 34 and posterior capsule 35 are connected to the ciliary sulcus 36, ~
a structure on the wall 20 of the eyeball immediately behind iris 24.

In the normal eye, light enters through cornea 22, passes ,;through anterior chamber 25 and pupil 26 and is focused by lens 30 to form an image on retina 37, a light-sensitive -tissue ~lining the rear portion o~ the eyeball. The retina converts this image into nervous impulses whiFh are transmitted to the B~6~

1 brain. The disease known as catara-t occurs when either the lens o~ the capsule becomes clouded or opaque. This interferes ' with transmission of light to the retina and hence interferes with vision. The only known cure for cataract is to remove S the affected tissue, In an "intracapsular" surgical technique, anterior capsule 3~, lens 33 and posterior capsule 35 are ~removed. In an l'extracapsular" procedure, only lens 33 and anterior capsule 34 are removed, posterior capsule 35 beiny Illeft in place within the eye. Many ophthalmologists have been i'trained only in the intracapsular technique and therefore prefer ,this technique over the extracapsular technique. The extra-capsular technique cannot be utilized if the posterior capsule is diseased or is damaged during surgery. ~

'' Once the lens has been removed from the eye, light entering the eye will not be properly focused on the retlna without some artificial aid. Such aid can be provided by eyeglasses or contact lenses, but these aids do not provide satisfactory vision correction, comfortand convenience in all cases. Intra- , ~ocular lenses, which can be surgically implanted within the leye, provide an alternative to eyeglasses and contact lenses.

~s generally utilized in the ophthalmologic art and as utilized herein, the term "intraocular lens" refers to an assembly including both a light focusing element or "optic"
,and ancillary structures which serve to anchor the optic in ~place within the eye. Presently available intraocular lenses are commonly categorized as either "anterior chamber", "iris supported" or "posterior chamber". ~nterior chamber lenses, designed for placement within the anterior charnber o~ the eye, 'ordinarily incorporate rigid supporting structures. When the lens is in place within the eye, guch suppor~ing structures are

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1 enyaged with the eye wall at the juncture of the cornea and the iris to retain the lens in position within the eye. As ; anterior chamber lenses do not depend upon the capsule to retain them in position within the eye, anterior chamber lenses ~can be implanted in the eye after an intracapsular extraction procedure, the extraction procedure most Eamiliar to the majority of ophthalmologists. Accordingly, anterior chamber lenses have been widely utilized. However, the rigid supporting l structures of anterior chamber lenses must be provided in Inumerous different sizes to accom~odate eyes of various sizes.
Moreover, either the optic or the supporting structures of ~an anterior chamber lens may irritate the cornea.
Iris supported lenses ordinarily incorporate an optic and a plurality of filamentary supports. When the lens is implanted 15 . I in the eye, the optic is disposed in the anterior chamber, the supports extending through the pupil and radially outwardly along the posterlor surface of the iris. Because the iris is engaged between the posterior surface of the optic and the supports, the iris retains the lens in position within the eye.
However, the iris can become disengaged from between the optic 'and the supporting elements upon extreme dilation of the pupil, thus leaving the lens free to move within the eye. In an attempt . .
to alleviate this problem, some iris-supported lenses have '~been provided with additional supports arranged to extend out-wardly from the optic along the anterior surface o~ the iris.
Also, iris-supported lenses have been provided with staves, spikes or sutures extending through the irls to more firmly anchor the optic thereto. Despit:e ~uch added f~atures, many 'surgeons pre~er to implant iris-supporte~ lenses only when the V ~

1 ' posterior capsule remains intact within the eye so that scar tissue can firmly attach the supports of the lens to the posterior capsule and anchor the lens in place. This preference, in turn, lidictates the employment of an extracapsular procedure for ''removing the natural lensO This has been an important deterrent ' to the use of iris-supported lenses. Moreover, if the capsule i,itself is diseased and must be removed, an extracapsular procedure I~cannot be utilized. Further, because the optic of an iris-!
lisupported lens is positioned in the antexior chamber, the optic 'can scràtch the cornea.

¦l In recent years, posterior chamber lenses have become more ~widely accepted. The optic of a posterior chamber lens is ' disposed in the posterior chambex when the lens is implanted.

l,Because the optic is remote from the cornea, the posterior chamber lS lens generally does not produce corneal irritation. However, the posterior chamber lenses available heretofore have generally depended on the posterior capsule for fixation of the lens within the eye. Accordingly, such lenses have requixed the use of an extracapsular surgical technique which leaves the posterior capsule intact. For example, the most widel~ adopted posterior chambex lens heretofore has been the so-called Shearing lens. This lens has two J-shaped resilient support members extending from its optic. The suppoxt members engage the wall of the eye in the ciliary sulcus immediately posteriorly 2S ' of the iris and effectively retain the optic against decentration or movement transversely of the axis of the eye. However, the "support members do not provide any substantial support against movement of the optic posteriorly within -the eye. Accordingly, the posterior capsule must remain intact if this lens is ukilized.

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) 2 1 SU~ARY OF T~IE INVENTION

The present invention provicles a pos-terior chamber intra-ocular lens which can be adequately anchored within the eye ` without relying on the capsule for such anchorage. Accordingly, the lens of the present invention can be utilized even if the posterior capsule has been completely removed as by an intra-capsular lens extraction procedure, or if the posterior capsule is damaged during surgery.
` The present invention also provides an intraocular lens suitable for implantation in eyes of different sizes so that the number of different lenses ~hich must be stoc~ced is minimized.
Moreover, the present invention provides a lens which, when implanted in the eye, is retained against posterior dislocation 15 by the iris and retained against decentration by engagement with the wall of the eyeball.
The lens of the present invention preferably includes an optic and support means for engaging an eye structure posterior of the iris to support the optic from such structure and prevent decentration of the optic. Retaining means for engaging the anterior surface of the iris are provided to pre~ent posterior dislocation of the optic.
The support means may include a radially extensive support structure, which structure may include support elements similar to those employed in the Shearing lens. The retaining means may include a radially extensive retaining structure connected ~to the optic, such structure being disposed anteriorly of the support structure. When the lens i.s impl~nted in the eye, the anterior surface of the opti.c confronts the posterior surface o~
the iris and the retaining elements confront the anterior surface ; 5 . . .

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1 , of the iris so tha-t the iris is engaged between the anterior retaining elements and the optic. The anterior retaining elements may be flexible and may be formed from filamentary material, such as polypropylene monofilament of the type normally utilized as a surgical suture. Preferably, the anterior retaining elements 1 , .
extend from the anterior surface of the optic. Each anterior retaining element may include a portion extending anteriorly i from the juncture of such retaining elemen-t with the optic and a radially extensive portion extending from such anteriorly , extensive portlon. The radially extensive portion of each ! retaining element may slope posteriorly from its juncture with the anteriorly extensive portion of such retaining element 1 to the tip of the retaining element remote from the optic. ~, lS 1` Other objects, features and advantages of -the present invention will be more readily apparent from the detailed description of the preferred embodiments set forth kelow when read in conjunction with the accompanying drawings.
~ : . f , : BRIEF DESCRIPTION OF THE DRAI~INGS
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Fig. l-is a schematic sectional view of a normal human eye , with the natural lens in plase.
, Fig. 2 is a view similar to Fig. 1 but depicting the ànterior I, portion of the eye with the na-tural lens removed and an intra-' ocular lens according to a first embodiment of the present , invention implanted.
I Fig. 3 is an anterior frontal view of the lens depicted '~ in Fig. 2.

Fig. 4 is a lateral elevational view of -the lens depicted 3û in Figs. 2 and 3.
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1 Figs. 5 and 6 are views similar to Fiys. 3 and 4, respectively, depicting a lens according to a second embodiment '~of the present invention.
I Figs. ~ and 8 are views similar to Figs. 3 and 4, , respectively, depicting a lens according to a third e~odiment of the present invention.

,, DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

1` As used herein to describe features of an intraocular lens, the terms "axis", "axial" and "axially" should be understood as referring to the optical axis of the optic, the axis of `~symmetry of the refractive surfaces of the optic. The terms - , . . . . .
~,"radial" and "radially" should be understood as referring to lS ',directlons transverse to such axis. The term "transaxial plane"
, should be understood as referring to a plane perpendicular to ~the axis of the optic, Also, the terms "anterior" and "posterior"
as used herein with reference to features of an intraocular lens , should be understood as referring to the relative positions and ,directions of such features in the normal, implanted position j,of the lens. Thus, for example, if a first feature of the lens ,is anterior of a second feature, then such first feature will ,be positioned closer to the front of the eye than the second Ifeature when the lens is implanted. The anterior and posterior directions are directions parallel to the axis of the optic.
- , As seen in Figs. 3 and 4, a lens according to a first embodiment of the present invention includes a rigid, disk-like optic 40 having a planar posterior surfac~ 4Z and a convex sub-stantia~,ly spherical an-terior surfa~e 44, anterior surface 44 being symmetrical about axis 46 of optic ~0. optic 40 also has .; .

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1 a generally cylindrical peripheral surface 48 concentric with axis 46, peripheral surface 48 extending from anterior surface 44 to posterior surface 42 at the margins thereof, A pair of diametrically opposed holes 50 extend through optic 40 parallel ,,~ to axis 46.
,ll The lens also includes a palr of retaining elements 52, such ',retaining elements being substantially identical with one iianother. Each retaining element consists solely of a single llfilament 54, each such filament being configured generally in Ithe shape of a U. The bight of each filament whiclh forms 'the base of the U defines the tip 56 oi the retaining element remote from axis 46. The portlons 58 of each filament 54 ,defining the legs of the U extend generally radlally. At the ~extremities of such portions remote from tip 56, each filament 1 is bent out of the planè of the U. As best seen in Fig. 4, l! . . ~ . , ',portions 60 of the filament extend from the leg portions 58 ~through the anterior surface 44 of optic 40, the tips of portions 60 being imbedded in optic 40. In other words, portions 60 of 1 each retaininy element extend anteriorly (to the left as seen ~~in Fig. 4) from the anterior surface 44 of optic 40, and the remainder of each retaining element extends radially outwardly from its juncture with anteriorly extending portions 60 of such ~retaining element to its tip 56. As will be apparent from Fig. 4, , the radially extensive portion of each retaining element slopes posteriorly (towards the right in Fig. 4) from its juncture with the anteriorly extensive portions 60 to tip 56. The two retaining elements 5~ are diametrically opposed to one another.
'That is, a line drawn between the tips 56 would cross axis 46.
Two support elements 62 are provided. Each support element is formed solely from a single filament 64 configured generally .

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, 1 , in the shape of a J. The bight of each filament de~ining the base of the J forms the tip 66 of support element 62 remote , from axis 46 of optic 40. The portion of each filament 64 defining the stem 68 of the J extends generally radially, the I,end 70 of each such portion remote f,rom tip 66 ex~ending through ' peripheral wall 48 of optic 40. Each such end is imbedded in optic 40. The portion 72 of each filament 64 defining the hook of the J extends from tip 66 of the support element towards ',optic 40, but the ends 74 of portions 72 are not irnbedded in 'l,optic 40. Because ends 74 ar'e exposed, they are preferably rounded or otherwise blunted.
, As best seen in Fig. 4, support elements 62 are disposed I .
, in a co~mon transaxial plane and are posterior of retaining 'elements 52. Support elements 62 are diametrically opposed to ' one another; a line drawn between the tips 66 of support elements would intercept axis 46. Also, each retaining element 52 is aligned with one of the support elements 62. When the lens is viewed in a f~ontal projection such as ~ig. 3, a radius drawn from axis 46 to the tip 56 of each retaining element 52 would , appear closely adjacent to a radius drawn from axis 46 to the tip 66 of the support element aligned ~ith such retaining ', element.
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As seen in Fig. 2, optic 40 is disposed in posterior chamber 1 33 when the lens is implanted in the eye. Portions of anterior :
sur~ace 44 of the optic confront the posterior surface of iris 24.
Axis 46 of optic 40 is suhstantially coincident with the anterior-posterior axis 28 of the eye. Tips 66 of support ' elements 62 are engaged with the ciliary sulcus 36 of the eye and support optic ~0 therefrom, The anteriorly extending portions 60 of retaining elements52 extend through pupil 26 and the -` ~ 164602 1 radially extensive portions 58 of the retaining elements overlie ~the anterior surace of iris 24. Thus, the retaining elements prevent dislocation or movement of optic 40 in the posterior ;Idirection (to the right as seen in Fig. 2) into vitreous llchamber 29. Because optic 40 is retained against decentration (displacement away from the axis 28 of the eye) by support l~elements 62, retaining elements 52 need not engagé the iris -l~in such fashion as to res1st decentration loads.

i, Support elements 62 are ordinarily flexed slightly inwardly lltowards axis 46 from the free or undeformed positions illustrated in Figs. 3 and 4 when they are engaged with the ciliary sulcus 36. The dimensionsr configuration and material of construction of support elements 62 are selected so that ,lwhen the support elements are engaged with the ciliary sulcus, ,Ithe support elements will exert a mild pressure on the c1liary sulcus sufficient to retain the support elements in engagement but insufficient to irritate the eye tissues. The open, J-shaped configuration of the support elements, best seen in Fig. 3, allows the support elements to deflect-radially inwardly ~over a wide range of positions with only minimal variations in the force which they exert on the eye tissues. Accordingly, the J-shaped support elements can be engaged with eyes of different sizes.

I Support elements 62 may be formed from any biologically and structurally suitable material, including polypropylene, polyamide or platinum, polypropylene being preferred. If each support ,element 62 is formed from a slngle filament of polypropylene, I each such filament is preferably about 0.14 to 0.17 mm. in diameter. ~he diameter across the tips 66 of the support elements (the diameter of the smallest circle concentric with i .

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1 axis 46 which completely encloses support elements62 in their ~ree or undeformed state) is preferably about 13 mm.
Retaining elements 52 are less flexible tha~ support ~ elements 62. The diameter across the retaining elements (the ' diameter of the smallest circle concentric with axis 46 which will completely enclose the retaining elements in their free or undeformed state) is less than the major diameter of the normal 'iris. Therefore, tips 56 of the retaining elements do not ' contact the wall of the eye, and the retaining elements need l'not deform radially inwardly to accom~odate eyes of different l~sizes. Preferably, the diameter across the retaining elements ',is about 7.75 mm. The width w (Fig. 3) of each retaining element is preferably about 2.0 mm. and the distance d between the two opposed retaining elements across the center of the lens is also preferably about 2.0 mm. The radially extensive ~portions 58 of the retaining elements preferably slope posteriorly at an angle of between about 5 and about 15, that is, the angle between each such radially extensive portion and a transaxial plane is about 5 to about 15. The length 1 (Fig. ~) of each of the anteriorly extending portions 60 of the retaining elements 52, as measured from its intersection with the radially extensive portion of such retaining element to its intersection with anterior surface 4~ of optic 40, is preferably between about 0.30 an~ about 0.43 mm. This arrangement provides appropriate spaces between the retaining elements and the optic, and between the retaining elements and the support elements, ;for insertion of the iris.

1 ~ The retaining elements can be formed from any of the materials referred to above in connection with the support elements, polypropylene being the preferred material. If ,each retaining element is forr.ed from a single filament of polypropylene, each such filament is preferably about 0.17 to O.21 mm. in diameter.
, optic 40 may be formed from any material having suitable optical, structural and biological properties. Polymethylmeth-llacrylate is preEerred. optic 40 may be about 6.0 mm. in diameter.
~The thickness of the optic, and the precise shape of its anterior surface, will be selected to provide the appropriate refractive effect for the particular eye.
One suitable technique for implanting the lens described ~above in the eye is as follows:
'. l. Remove the natural lens of the eye by conventional surgical procedure, leaving a wound opening in the wall of the eyeball adjacent to the top of the eye just anteriorly of the iris.
2. Clear the anterior chamber of any vitreous material ',until a single air bubble fills the chamber and there is no distortion of the pupil by strands of vitreous material.

3. Maintain the shape of the anterior chamber

4. Adjust the size of the wound opening to between about j,7.0 mm. and about 8.0 mm.

5. Insert a lens gllde carefully through the wound and through the pupil so that the inserted end of the lens glide is ~behind ~he iris and positioned at -the bottom or inferior portion of the eye.
j 6. Use acetyl choline chloride if necessary to adjust -the `diameter of the pupil to less than 6.0 ~m.

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1 ~l 7. Grasp the retaining elements with a smooth McPherson forceps so that the jaws of -the forceps are parallel to the retaining elements and support elements. Hold the forceps so ' that one support element is lower than the other.
i, 8. Lift the cornea with one hand to clear the retaininy elements while inserting the lower support elemen-t and the ¦ optic along the glide. Press yently on the glide in a posterior ¦ direction while passiny the optic into the anterior chamber of the eye and lnsert the lower support element and the lower I portion of the optic through the pupil. Engage the iris between the lower portion oE the optic and the lower retaining element. -~ 9 ~ Continue to hold the cornea and remove the forceps 15 1l from the retaining elements. Grasp the upper support element, ,, ¦I compress it slightly and place it just inslde the eye ~, ¦l anteriorly of the iris at the juncture of the irls and theeye wall at the top of the eye. 'Release the upper support ¦ element so that it lodges in the angle between the iris and ¦'~ the eye wall, and check if the lens remains in place. If it I does, this indicates that the support elements are of sufficient -ll size to properly enyage the eye wall. ; ; , 10. Pass a Bonn hook beneath the lens and retract the pupil at about the 1:30 o'clock position. Insert a 5inskey hook !l into the operculum adjacent the top of the lens and pivot the 1I top portion of the lens posteriorly while éxerting slight ,¦ in~erior and posterior pressure until the upper support element il is disposed posteriorly of the iris and ~he iris is disposed between the optic and the upper ret,aininy element.

Il , .
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a 2 11. Using a hook or forceps, lift the lens gently and rock `it along the axis of the suppor-t elements to assure that the '~ tips of the support elements are engaged in the ciliary sulcus.
, 12. Perform a peripheral iridectorny or iridotomy ~l 13. If desired, a suture may be placed through the iris and around one of the retaining elements.
14. Close the wound.
I A lens according to a second embodiment of the present llinvention is depicted in Figs. 5 and 6. The optic 140 and llretaining elements 152 of this lens are similar to the optic 40 and retaining elements 52 of the lens described above with reference to Figs. 3 and 4. The support elements 162 of the l! lens shown in Figs. 5 and 6 are J-shaped, but the stems 168 11 of such support elements are curved rather than straight. The ends 170 of stems 168 intersect peripheral surface 148 of optic ! 140 almost tangentially as seen in Fig. 5. The diameter across the support elements 162 is between about 13.35 and about 13.65 mm. when the supporting elements are in their free or undeformed ~'state. Each of the support elements 162 is formed from a il I
~polypropylene filament 164 between about 0.14 and 0.17 mm. in diameter. The end 174 of each support element filament 164 at the extremity of the hook portion 172 of such support element is formed into a blunt knob slightly thicker than the diameter of ,,the filament. The term "blunt" as used herein refers to a structure which is devoid of sharp edges which might irritate eye tissues.
A lens accordinq to a thirdembodiment of the present invention is depicted in Figs. 7 and 8~ 'rhis lens incorpora-tes an optic 240 and support elemen~s 262 similar -to the optic and ., .

1 ~' support elements of the lens described above with reference to Figs. 5 and 6. The retaining elements 252 of the lens ¦ depicted in Figs. 7 and 8 are J-shaped rather than U-shaped.
, Each retaining element 252 is formed from a single polypropylene ,~ filament 264 and incorpora-tes a sinyle anteriorly extensive portion 280 which intersects anterior surface 244 of op-tic 240.
A curved stem portion 282 extends generally radially from its intersection with anteriorly extensive portion 280 to bight 284 which forms the tip of the re-taininy element. Each such radially extensive portion 282 slopes posteriorly from its intersection with anteriorly extensive portion 280 towards I¦ tip 284. A portion 286 of each retaining element filament l¦ extends back towards optic 240 from tip 284 so that portion 286 ¦¦ at hook defining portion 286 is remote from optic 240 and is not , engaged therewith. Rather, a blunt knob 288 is formed at such end o~ the filament. As best seen in Fig. 8, each knob 288 ¦ projects anteriorly of the filament but does not project posteriorly thereof. Therefore, knobs 288 will not engage the !l iris when the lens is implanted in the eye.
jl The length l'of each anteriorly extensive portion 280 is ! preferably about 0.4 mrn. as measured from its intersection with optic anterior surface 244 to its intersection with the ¦ associated stem portion 282. Each stem portion 282 preferably 25 1l slopes posteriorly from its intersection with an-teriorly extensive portion 280 a-t an angle of between about 3 and about 5, although any angle of posterlor slope greater than 0 may be utilized, and angles of more than 5 may be utilized if the lens is especially thick. ~lowever, the anterior to posterior distance from the tip 284 of each retaining element to the plane of the . . , I -15~

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1 support elements should not be less than about 0.5 mm. or more than about 0.g mm.
If the retaining elemen-ts 252 are formed from polypropylene li filaments, such filaments are preferably about 0.14 to 0.17 mm.
l in diameter. As each retaining element 252 is engaged with optic 240 at only one end, retaining elements 252 are signifi-cantly more flexible in the radial direction that the retaining elements of the lenses described above with reference to Figs. 3 l through 6. Preferably, the diameter across the retaining elements 252 in their free or undeformed state is about 10.5 mm. Thus, , tips 284 of the retaining elements extend far enough from the axis 2~6 of the optic so that when the lens is implanted in a normal human eye tips 284 will ex-tend to the periphery of the il iris and engage the wall of the eyeball. Thus, retaining 15 1~ elements 284 may provide additional support against decentra-tion of optic 240. However, because retaining elements 252 are Il quite flexible in the radial direction, they can accomodate ,' dif~rent eye sizes and they will not exert undue pressure ~ against the wall of the eye. Also, because retaining elements l 252 extend all the way to the periphery of the iris, they may provide greater security against disengagement upon dilation ofthe pupil, and hence may provide greater security against posterior dlslocation of the optic.

'I Lenses according to the present invention have given good 25 11 results in trial implantations The first such lens was implanted in an instance where a rupture of -the posterior I capsule was suspected. Observa-tion of the flrst eye for three 'j months revealed good results. Further implants or this type ,~ of condition were carried Ollt on six patients. The patients were observed during follo~-up periods after implantation in , ., :, .

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1 ,' accordance with norma]. investi~ational practice. These patients j had very good results considering that rupture of the capsule I, often creates suscep-tibility to other complications. The ! results of these trial implantations are summarized in Table I

5 1! below.
i 1, TABLE I

li Follow-up ¦l- Vitreous Visual Acuity at Period After j~ Patient Age/Sex Loss - Last Follow-up Implantation Notes ~¦ 1 69/F NO 20/30 12 .~onths 1 2 68~ YES 20/30 ~ 9 Months 3 88/F YES 20/25 4 Months 4 68/F NO -20/20 ;4 Months ~1 5 73/M YES 20/20 3 Months 1l 6 52/M YES 20/20 3 Months 2 7 80/F YES 20/40 3 Months 3 ~ NOTES:

! 1. Capsule disinsertion -- required capsulotomy at two months.
'I !
20 1 2. Retained cortex in vitreous cleared at two months.
i 3. Nuclear fragment in vitreous removed from anterior cha~ber two weeks post op. and lens inserted.
., Lenses according to the present invention also were used 1 in patients who had had an intracapsular cataract operation at ~ ;
, some time prior to implantation. Five of these implantations were perfor~ed with good results, summarized in Table II.

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.j , ~l 1 , TABLE II

Follow-up Vitreous Visual-Acuity at Period After Patient Age/Sex Loss Last Follow-up _ Implantation Notes li t~ 87/FPLANNED 20/40 3 Months ,t 9 73/FNO 20/40 ~2 Months 2 57/MYES 20/25 6 Months 3 tllll 76jMNO 20/20 !2 Months 1!12 66/MNO ~20/20 - ~ 2 Months il . - .--. - .: !
I_____ _________________ _______ __ ________________________________ ~¦ NOTES: ' ' ¦¦l. Residual astigmatism 5 diopters.
¦ 2. Small vitreous herniation into anterior chamber.
I 3. Lens exchange -- loose 3 loop Binkhort lens.

1~ As will be readily appreciated, numerous var1a-tions and 'l~combinations of the features described above can be utillzed ¦¦without departing from the present invention. Merely by way of example, the retaining elements need not be aligned with ithe support elements as in the embodiments described above.
!¦ I
Also, additional retaining elements, additional support elemen-ts, or both, may be provided. As these and other variations may t ¦be util1zed, the foregoing description of the preferred embodi- t l¦ments should be understood by way of illustration rather than 25 1l by way of limitation of the present invention as defined in the claims.

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Claims

The embodiments of the invention in Which an exclusive property or privilege is claimed are defined as follows:

1. An intraocular lens for placement in the posterior chamber of the human eye, said lens having an optic, support means for engaging eye structure to support the optic in said posterior chamber in alignment with the eye anterior-posterior axis, and retaining means for engaging the anterior surface of the iris to impede posterior dislocation of the optic, characterized in that the support means includes a pair of filaments embedded in the optic at the posterior side thereof, the retaining means includes a pair of filaments embedded in the optic at the anterior side thereof, all said filaments extending radially from the optic and having tips remote from the optic which are devoid of sharp edges, the support filaments and retaining filaments being located at generally diametrically opposed locations on said optic with each support filament being aligned with one of the retaining filaments, the tips of all said filaments being defined by a bight included in the respective filaments.

2. A lens as claimed in claim 1, characterized in that each of said retaining filaments is formed in the shape of a U, the base of such U being remote from the optic and forming the tip of the retaining element.

3. A lens as claimed in claim 1, characterized in that each of said retaining filaments is formed in the shape of a J, the base of such J being remote from the optic and forming the tip of the retaining filament.

4. A lens as claimed in claim 2 or 3, characterized in that each of said support filaments is formed in the shape of a J, the base of such J being remote from said optic and forming the tip of the filament.

5. A lens as claimed in claim 2, characterized in that the diameter between the tips of said retaining filaments is less than the major diameter of the normal human iris.

6. A lens as claimed in claim 5, characterized in that said diameter is about 7.75 mm.

7. A lens as claimed in claim 3, characterized in that the diameter between the tips of said retaining filaments is greater than the major diameter of the normal human iris.

8. A lens as claimed in claim 7, characterized in that said diameter is about 10.5 mm.

9. A lens as claimed in claim 3, characterized in that the diameter between the tips of said support filaments is about 13 mm.

10. A lens as claimed in claim l, characterized in that said support filaments and said retaining filaments are each of polypropylene and the diameter of the support filaments is in the range about 0.14 to 0.17 mm and that the diameter of the retaining filaments is in the range about 0.14 to 0.21 mm.

11. A lens as claimed in claim l, characterized in that each of said retaining filaments includes an anteriorly extensive portion and a radially extensive portion, said anteriorly extensive portion being connected to the optic.

12. A lens as claimed in claim 10 characterized in that the radially extensive portion of each retaining filament slopes posteriorly from its juncture with the anteriorly extensive portion to the tip thereof.

13. A lens as claimed in claim 11, characterized in that radially extensive portion of each retaining filament is disposed at an angle of about 3 to 5 to the transaxial plane of the optic.

14. A lens as claimed in claim 11, characterized in that the minimum anterior to posterior distance between each retaining filament at its tip and the support filament aligned therewith is between 0.5 mm. and 0.8 mm.