CA2006712A1

CA2006712A1 - Intraocular lens with expandable haptic

Info

Publication number: CA2006712A1
Application number: CA002006712A
Authority: CA
Inventors: Fred T. Feaster
Original assignee: Individual
Current assignee: FEASTER FRED
Priority date: 1989-04-13
Filing date: 1989-12-27
Publication date: 1990-10-13
Also published as: WO1990011736A1; JPH03505687A; EP0419601A4; US4902293A; EP0419601A1

Abstract

Abstract of the Disclosure The intraocular implant has a solid, non-inflatable, non-expandable, transparent optic member and an expandable haptic means coupled to the outer periphery of the optic.
The haptic means is expandable after insertion into the eye, in a first embodiment, by externally injected fluid, and in a second embodiment, by liquid from the aqueous of the eye.
In the first embodiment the haptic means is inflatable. In the second embodiment the haptic means is formed of a material capable of combining with or taking up liquid from the aqueous of the eye resulting in expansion of the haptic means.

Description

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INTRAOCULAR LENS_W TH EXPANDABLE HAPTIC
Speci ication This application is a continuation in part of U. S.
Patent Application Serial No. 07/337,260, filed April 13, 1989.
Backqround of the Inve~tion Field of the_Invention The invention relates to an intraocular lens for the human eye.
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Descriptio~ of the Prior Art It has been a continuing goal in ophthalmology to develop an intraocular lens which can be placed through the smallest incision possible. There have been four basic approaches to intraocular lens design to accomplish this task:
1. The development of intraocular lens implants made of flexible materials which are foldable and can be implanted through a small incision in their smaller, folded state, to then have the implant unfold to its full size within the eye. Examples of such foldable designs are seen in the patent of Mazocco 4,573,998.

2. The development of intraocular lens implants made of expandable materials which combine witll water and which are implanted into the eye in their smalle~, dehydrated state and then expand their volume once they are placed `"
into the liquid-containing interior of t~le eye. ;
Examples of this type of design are seen in patents `~
4,556,998 and 4,734,095 by Siepser, and 4,710,194 by `
Kelman, and 4,449,257 by Koeniger.

3. The development of intraocular lens implants containing two or more separate or moveable pieces which required ~ ., ;,' ..
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2006~2 construction once placed within the eye. In some designs, the pieces are connected together but require repositioning (such as sliding) within the eye after implantation. Examples of this type of design are seen in patent 4,056,855 by Kelman, 4,636,210 by Hoffer, and 4,6~,716 by Mackool.
4. ~ntraocular lens implants constructed to have an inflatable optic c~amber or compartment which is expandable within the eye by means of in~ection of a suitable fluid-like material into the initially deflated chamber which then expands to produce the optic when completely inflated. This type of design is seen in patents 4,585,457 by Kalb, 4,693,717 by Michelson, and 4,373,218 by Schachar.
Presently, with currently available technology and materials, it appears that the inflatable type of intraocular len~, which can be implanted in its uninflated, rolled up or compressed condition and then re-expanded in the eye with injection o~ the proper fluid-like material, stands the best chance of bein~ the implant design implantable through the smallest incision. IIowever, all of the existing inflatable designs proposed to date involve inf~ating the optic and that is a very unacceptable design feature because, by involving the optic in the inflation process, the optical quality of the implant is necessarily affected by and dependent on the inflation prdcess. More specifically, the optical quality and function will depend on the exact volume and quality o~ fluid-like material injected during the inflation process, and the skill of the surgeon performing the inflation. Also, the possibility of leaks from the inflated optic cavity might result in a change in the optic shape (and therefore its optical power) and forever threatens the fu~ure optical quality of the implant. This dependency of the optical quality (and '''' ;`' S ~ ' ' , o ' :.. , .,".,.~ . ","" ~

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therefore the i~plant's ability to restore good vision to the patient) on the inflation o~ tpe optic is a sexious and permanent design flaw for any infl~table design involving the optic. This possible optical variability is also a potential problem in those designs in which the optic dimensions will change with the combination of the optic material with fluid, such as the designs of Siepser. To a lesser extent, the optical quality of foldable materials is a potential problem which has been largely overcome through materials development. Potentially, the problems of the inflatable optic designs can likewise be overcome, however, there does not appear to be a practical and usable solution `
available in the near future. ~;
Therefore, it would be desirable to develop an implant design which incorporates the advanta~eous features of inflation or expansion for volume reduction/enlargement to allow implantation throuyh the smallest incision possible, and yet has an optic o~ established and constant optical quality which is independent of the inflation or expansion mechanism. ;
Summary of_the I~ve~tio~
It is an object of the invention to provide an intraocular implant comprising a non-expandable optic which comprises a haptic means which is expandable by fluid. In this way, the optic qualities are completely independent, stable and unchanging regardless of the success and quality of the expansion process.
Difficulties with the expansion of the haptic, should they occur, would affect only optic centration and not optic quality.
It is a further object of the invention to provide an intraocular implant for use as an artificial lens implant in a human eye and which comprises a, non-expandable, solid optic member having a central axis and .. .... ....

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an outer periphery and an expandable haptic means coupled to the outer ~eriphery of the optic member. The haptic means is expandable after insertion into the eye, in a first embodiment, py externally injected fluid, and in a second embodiment by moisture in the eye.
In the first embodiment, the in~latable haptic means comprises a flexible wall structure coupled to the outer periphery of the optic member defining at least one enclosed chamber for receiving a fluid for inflating the haptic means.
In the second embodiment, the haptic means is formed of a material capable of combining with or taking up liquid from the aqueous of the eye resulting in expansion of the haptic means.

Brief Description of the Drawinqs Fig. l is a plan view of the intraocular implant of a first embodim0nt of the invention with the haptic uninflated.
Fig. 2 is an enlarged cross-section of Fig. 1 taXen along lines 2-2 thereof.
Fig. 3 is an enlarged cross-section of the intraocular implant of Fig. 1 with the uninflated haptic in a folded position.
Fig. 4 is an enlarged cross-section of the intraocular implant of Fig. l with the haptic inflated.
Fig. 5 illustrates the intraocular implant, in cross-section, with the haptic inflated and positioned within the capsular bag o~ a human eye.
Fig. 6 is a cross-sectional view of the intraocular implant illustrating one-way valves for use for inflating the chamber of the haptic.
Fig. 7 is a plan view of a modification of the embodiment of Fig. 1-6 with the haptic members uninflated.

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Fig. 8 is an enlarged cross-saction of Fig. 7 taken along lines 8-8 thereof.
Fig. 9 is an enlarged cross section of ~he intraocular implant of Fig. 7 with the uninflated haptic members in folded positions.
Fig. 10 is an enlarged cross-section of the intraocular implant of Fig. 7 with the haptic members inflated.
Fig. 11 is a plan view o~ a second embodiment of the invention with the haptic unexpanded.
Fig. 12 is an enlarged cross-section of Fig. 11 taken along lines 12-12 thereof.
Fig. 13 is an enlarged cross-section of the intraocular implant of Fig. 11 with the haptic expanded.
Fig.14 is a plan view of a modification of the embodiment of Figs. 11-13 with the haptic members unexpanded.
Fig. 15 is an enlarged cross-section of Fig. 14 taken along lines 15-15 thereof.
Fig. 16 is an enlarged cross-section of the intraocular ~
implant of Fig. 14 with the haptic members expanded. ~ -Description of the Pre~erred Embodiments `~
Referring now to Figs. 1-6 of the drawings the intraocular implant of the invention is identified at 21. It comprises a solid non-inflatable, non-expandable, transparent optic member 23 having a central axis 25 and an ;i~
outer periphery 27. Coupled to and circu~ferentially surrounding the outer per~phery 27 o~ the optic member 23 is a haptic member 31. The haptic member 31 comprises thin ~lexible wall structure 33 joined to and circumferentially surrounding the outer periphery 27 defining an enclosed ;
generally annular chamber 35 for receiving a fluid such as a gas or a liquid or other ~luid-like material for inflating the haptic member 31. As shown in Fig. 6, one or more small o~enings 37 may be formed through the wall 33 of the haptic 2~DI[16'7~:~
_~ 6 means 31 to which are coupled ~ubes 39 with one-way valves 41 to allow the fluid to be injected into t~le chamber 35 for inflation purposes. The one-way valves 41 allow fluid to flow only into the chamber 35 and prevents the ~luid from flowing out of the chamber 35.
The inflatable haptic member 31 is constructed to surround and attach to the outer periphery o~ the central optic 23. The haptic member 31 is formed of a thin flexible material which may also be an elastic or resilient material.
It may be formed in its generally annular shape and then bonded to the outer periphery of the optic 23. In its uninflated condition (Fig. 2), it is essentially flat and can be folded over the optic 23 (Fig. 3) minimizing the volume of the implant 21 thereby permitting implantation through an incision size (Pormed through the cornea 51 o~
the eye 53) determined primarily by the dimensions and volume Q~ the optic. once inside the eye, tlle implant is intended to be positioned entirely within the capsular bag 55 (behind the iris 57), where the haptic is then in~lated for fixation and centration of the optic (Fig. 5). Therefore, it can be seen that the entire implant, comprised of the central non-inflatable and non-expandable optic and surrounding in~latable haptic member (in its uninflated condition), will be implantable through a very small incision. Further, as mentioned, the problems with optic quality 'are totally avoided. Therefore, a lens o~ high and unvarying optical quality with small incision implantation capability is provided.
The haptic member 31 is inflated by injecting a suitably biocompatible fluid, which preferably is a liquid or other flowable liquid-like material but which may be a gas, into the chamber 35 whlch is ultimately defined and limited by the distensibility o~ the material comprising the :. . . . ..

2~6712 haptic cavity wall 33. The injected fluid-lik~ material or liquid may or may not develop a certai~ fixed shape or "harden". It can be seen that requirements o~ such a fluid-like material are considerably less ~tringent than requirements for materials which are injected into an optic space. That is to say, the biological properties of a fluid-like material which is iniected into a haptic space are not as demanding as the biological properties o~ a material injected into an optic space and therefore are not as dif~icult to develop.
The fluid-like material may be injected into the inflatable haptic space 35 through the small conduit 39 with the aid of a small tubular needle with the one-way valve 41 allowing fluid flow in only one direction (toward the haptic chamber only~ (Fig. 6). The material is injected until the haptic chamber is seen to be completely distended and the optic appropriately centered. In one embodiment, the one-way valve 41 may be of the type disclosed in U.S. Patent No. 4,585,457, althouyh other types of one-way valves may be used. Another mechanism for preventing mat.erial leakage is to employ only the conduit 39 and to seal its opening by heat, glue or other means after injection is completed. In an alternative, the conduit 39 may not be employed and a sharp injection needle used to pierce the wall of the haptic to inject the fluid into the space 35 after which the needle is withdrawn and the opening sealed by heat or'glue. Also the haptic may be ~ormed of a silicone type material such that the opening ~ormed by the needle becomes self-sealing.
The wall of the inflatable haptic member is constructed of a thin, "foldabl~" or pliable material which may be an elastic or resilient material which defines the outer dimensions and configuration of the inflatable haptic member upon injection of a suitable biocompatible material. The wall material of the haptic member is nonpermeable to the injection material ;, ~ .

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_~ 8 to prevent leakage of the injection material through the wall and into the eye.
In the preferred embodiment, the configuration of the haptic member 31 is generally annular such that the central optic 23 is surrounded 360 degree peripherally and circumferentially by the haptic member 31 which when inflated is in the shape somewhat like that of an inflated inner tube. This will then give a complete circumferential type of contact between the haptic and the outer tissue (the lens capsule when placed within the cap~ular bag) which is recognized to be probably the most secure and desirable type of intraocular lens fixation attainable. The cross-sectional area of the inflated space 35 may be generally circular (Fig. 4), although it may vary considerably from this general con~iguration, particularly in decreasing the anterior/posterior dimension, while maintainillg the radial dimen~ion. Approximate dimensions for a pre~erred embodiment of the implant 21 comprises an optic measuring approximately 6 to 7 mm. in diameter, with the haptic cavity inflatable to give an overall diameter of the insert 21 of approximately 10-13 mm. It is to be understood that the implant 21 may have different dimensions.
In one embodiment, the optic 23 may be formed of polymethylemethacrylate or other suitable materials such as a foldable silicone-like material that will return to its original unfolded shape after it is released fromlits folded condition. The optic 23 may be circular or oval in shape.
Folding of the optic member may be desirable in order to ~urther minimiæe the size of the incision in the cornea. The haptic member 31 may be formed of a suitable silicone or silicone-like elastomers. The optic 23 and the haptic member 31 may be formed initially separately and the haptic member 31 located around the outer periphery 27 of the optic 23 and bonded or attached to the outer periphery.

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The fluid employed to inflate the haptic member 31 may be solutions of physiologic salts (index 1.33 to 1.44) and Dertran (index 1.39 to 1.4) or a polymeric material such as a Silastic as disclosed in U.S. Patent No. 4,585,457. Other fluid type materials that may be employed to inflate the haptic member 31 are disclosed in U.S. Patent: No. 4,693,717.
Referring to Fiqs~ 7-lo, the intraocular implant 21 of Figs. 1-6 has been modified in that instead of having a single inflatable haptic member 31, two separate inflatable haptic members 3lA and 3lB are bonded to the periphery 27 of the optic member 23 such that they are separated by spaces 31S. Each haptic member 31A and 31B is formed of the same material as haptic member 31 and has a cavity 35 into with a fluid, of the type mentioned above, may be injected to inflate the two haptic members 31A and 31B, after the implant 31 i5 implanted into the eye as descrlbed above.
Each haptic member 31A and 31B may have conduit 39 and a one way valve 41, as described above, through which the fluid may be injected into the cavity thereof for expansion of the members 31A and 31B. In the alternative, each haptic rnember 31A and 31B may have only a conduit 39 as described above, through which the fluid may ~e injected and its opening sealed after the injection is completed. As a further alternative an injection needle may be employed to pierce the wall of the haptic to inject the fluid and heat, glue, or self-sealing haptic material employed to seal the opening formed by the needle as described above.
The advantage of having at least two inflatable haptic members 31A and 31B is that folding thereof may be easier during implantation. In addition, if the fluid to be injected is the type that "hardens", the use of two separate inflatable haptic members 31A and 31B has advantages, in that since each cavity is smaller than the cavity of haptic member 31, each cavity of haptic members 3lA and 3lB may be )67~2 filed quicker, thereby minimizing any problems o~
"hardening" of the fluid occurring before the smaller cavities are ~illed.
Referring now to Figs. 11-13 of the drawings, the intraocular implant of this embodiment is identified at 121.
It comprises a solid, non-inflatable, non-expandable, transparent optic member 123, similar to that of member 23, having a central axis 125 and an outer periphery 127. The member 123 is circular or oval in plan view as is optic member 23. Coupled to and circumferentially surrounding the outer periphery 127 of the optic member 123 is a solid haptic member 131. The optic member 123 is surrounded 360 degree peripherically and circumperentially by the haptic member 131. The haptic member 131 is formed of a material capable of combining with or taking up water from the a~ueous of the eye result~ng in expansion of the haptic member after insertion into the eye for enga~ing tissue of the e~e (the capillary bag) ~or supportin~ the optic member 123 in the desired position in the eye.
The haptic member 131 may be formed in its generally annular shape and then bonded to the outer periphery of the optic 123. In the alternative, as shown in Figs. 14-16, the haptic may comprise two separate arc-shaped solid members 131A and 131B each having a plan view similar to that o~
members 31A and 31B and which are bonded to the outer periphery 127 of optic 123 as members 31A and 31B are bonded to optic 23 such that members 131A and 131B are separated by spaaes 131S.
Suitable materials that the haptic member 131 and haptic members ~31A and 131B may be formed of are disclosed in U. S. Patent Nos. 4,556,998, 4,734,095, 4,710,194 and 4,449,257 which are incorporated herein by reerence. In the preferred embodiment the haptic member 131 and two arc-shaped solid haptic members 131A and 131B are formed of the ` 2~06~Z

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material identified in U. S. Patent No. 4,449,257 as Hydroxyethyl Methacrylate abbreviated as HEMA. Since the haptic members 131 and 131A and 131B are in the dry state when the implant 121 is inserted into the eye the members 131 or 131A and 131B may not be folded relative to the optic 123 during the implantation process. Once lnside the eye, the implant is intended to be positioned entirely within the capular bag 55 (behind the iris 57). In this position, over a period of time, the liquid from the aqueous of the eye will combine with or be taken up by the material of the haptic member 131 (or the two arc shaped solid haptic members 131A and 131B) causing it (them) to expand and engage the inside of the capsular bag and position and support the optic 123 in the desired position in the eye.
The optic 123 may be formed of the same material as is optic 23. In the embodiment of Figs. 11-16, the optic 123 may be formed of a foldable material that will return to its orlginal un~olded shape a~ter it is released from its folded condition. Folding of the optic member 123 may be desirable in order to further minimize the size of the incision in the cornea.
The haptic members 31A and 31B and 131A and 131B may havs shapes different from that shown. In addition, more than two inflatable haptic members may be coupled to the periphery o~ ~he optic 23 and more than two solid liquid expandable haptic members may be coupled to the'periphery of the optic 123.
In summary, a unique intraocular lens design incorporating a central non-expandable optic having attached to its periphery an expandable haptic member (or haptic members) which fixates and centers the optic within the eye (within the capsular bag) is provided. The implant is inserted into the eye with its haptic in its unexpanded configuration to minimize insertion wound size requirements, 20~)6~

and then the haptic member or members is (are) expanded in the first embodiment by injection of a suitable biocompatible material into the haptic once the i~plant is positioned loosely but completely within the capsular bag and in the second embodiment by liquid uptake from the aqueous of the eye. This new design avoids the problems of optical quality inherent in any design in which the optic is inflated or expanded, yet still possesses the desirable features of a small incision lens with excellent fixation characteristics. This design solution to small incision implants provides a safer and more practical solution than those inflatable or expandable designs which involve the optic.

Claims

An intraocular implant suitable for use as an artificial lens implant in a human eye, comprising:
a non-expandable optic member having a central axis and an outer periphery, and inflatable haptic means coupled to said outer periphery of said optic member for engaging the tissue of a human eye and positioning said optic member in the eye when said haptic means is inflated.
The intraocular implant of claim 1, wherein:
said optic member is formed of a material capable of being folded and which after being released from its folded condition will return to its original unfolded shape.
The intraocular implant of claim 1, wherein:
said inflatable haptic means comprises at least two separate inflatable members.
An intraocular implant suitable for use as an artificial lens implant in a human eye, comprising:
a non-expandable optic member having a central axis and an outer periphery, and expandable haptic means coupled to said outer periphery of said optic member for engaging the issue of a human eye and positioning said optic member in the eye when said haptic member is expanded, said expandable haptic means being formed of a material capable of taking up liquid from the aqueous of the eye resulting in expansion of said haptic means after implantation in the eye.
The intraocular implant of claim 4, wherein:
said expandable haptic means comprises at least two separate expandable members formed of said material.
6. The intraocular implant of claim 4, wherein:
said expandable haptic means circumferentially surrounds said outer periphery of said optic member.