OPEN LOOP WITH GRIPPING AREA FOR INTRAOCULAR LENS

Abstract: A haptic loop for positioning as the superior loop (40) (40') in an intraocular lens. The loop is an open loop attached to the lens body (16) at one end (42) and has a free end at the opposite end (44). To aid in implantation, the loop has a discontinuity (46) in the curve thereof to keep a non-gripping instrument (38) from slipping. In one embodiment, the discontinuity (46) is in the form of a notch (48). In another embodiment, the discontinuity (46) is in the form of a bead enlargement (50) on the strand (40) (40').

Description: OPEN LOOP WITH GRIPPING AREA FOR INTRAOCULAR LENS Background of the Invention The present invention relates to intraocular lenses and, more particularly, to improvements in open-strand loops used to support the lens body. Intraocular lenses were first introduced in 1948. For many years, their acceptance and development was limited. In the past few years, however, intraocular development and the introduction of new models has escalated rapidly. In addition to the development of new designs of intraocular lenses for purposes of improving such features as centration and fixation, much has been learned about the techniques of implanting lenses so as to minimize trauma to the eye itself. As a consequence, many of the changes in introocular lens design have been made to make the implantation procedure have a minimum probability of causing trauma. One family of intraocular lenses is that shown in simplified form in Figs. 1 and 2. These lenses incorporate at least one sweeping, curved. open-ended strand haptic member. It should be understood that as Figs. 1 and 2 are viewed, this is the view that a surgeon would have when standing at the head of a patient ready for implantation. The surgeon normally stands above the patient's head with the patient's feet extending away from him. Thus, the bottom of Figs. 1 and 2 represents the superior portion of the eye and the top of these two figures represents the inferior portion. Figs. 1 and 2 show the basic elements of implanting such a lens. An incision 10 is made in the superior portion of the eye adjacent the iris 12. The lens, generally indicated as 14, comprises a lens body 16 of plastic having an inferior loop 18 a nd a superior loop 20 extending outward therefrom generally in the plane of the lens body 16. Some lenses have the loops angled at 10°, but such angling is substantially of no consequence for purposes of the present invention. Each of the loops 18, 20 has one end attached to the lens body 16 and has a free end on the opposite end. The inferior loop 18 is passed through the incision 10 through the pupilary opening 22 into the posterior chamber (behind the iris) of the eye. The inferior loop 18 is followed by the lens body 16 and the superior loop 20. When thus placed, the lens 14 appears as shown in Fig. 1. To complete the implantation, the superior loop 20 must be compressed sufficiently so as to pass through the pupillary opening 22. This can be accomplished in several ways. The inferior loop 18 can be totally or partially compressed as shown in Fig. 2. Additionally, as also shown in Fig. 2, the superior loop 20 can be compressed towards and around the lens body 16. Additionally, (not shown) an instrument can be inserted through the incision 10 to grasp the inner edge of the iris 12 adjacent the pupilary opening 22. The instrument can then be used to pull the iris 12 back towards the incision 10, thus enlarging the pupillary opening 22. With both the inferior loop 18 and superior loop 20 positioned behind the iris 12, the lens 14 can be released and will then assume a centered position due to the equal springing effect of the two loops 10 18, 20. One aspect of lens implantation that has been generally recognized and accepted is that the incision 10 should be made as small as possible and be closed as much as possible as soon as possible. * Typically, much of the work is done with micro-forceps such as those indicated as 24 in Fig. 3. Fig. 3 is drawn substantially to scale so as illustrate the fairly large relative size of the forceps 24 with respect to the environment wherein they are used. It is desirable, if possible, to eliminate or minimize the use of large instruments such as the forceps 24 in any maneuver which requires that entry be made through the incision 10 5 into the eye itself. Some skilled surgeons have been able to implant lenses such as those shown in Figs. 1, 2, and 3 by making the initial placement of Fig. 1 using the forceps 24 only external to the eye in the manner shown in Fig. 3. Thereafter, the ° compression of the loops 18, 20 to complete the implantation is accomplished by inserting a micro-hook through the incision 10 into engagement with one of the positioning holes 26 provided adjacent " the periphery of the lens body 16. The lens body 16 is then rotated about its center axis using the micro-hook (not shown) whereby the lens body 16 is essentially "screwed" through the pup[ilary opening 22 of the iris 12 in a manner which causes the iris 12 to collapse the loops 18, 20 in their passage through the pupilary opening 22. Unfortunately, a great many physicians are unable to use this maneuver either by choice or because of lack of skill. One prior art lens capable of compression with a minimum-sized instrument is shown in Fig. 4. The lens generally indicated as 28 in Fig. 4 is a design of Dr. John H. Sheets which is sold as the "style 30" lens by McGhan Medical Group. The Sheets lens 28 comprises a lens body 30 having a pair of opposed haptic members 32 extending therefrom. The haptic members 32 are closed loops having a compound curve such that four points of contact are created. The two inner points 34 are generally fixed and immobile. The two outer points 36 are cantilevered to create a state of compressibility. To create the compressibility and provide only the two points of contact 34, 36, the haptic member 32 is bowed inwardly towards the lens body 30 between the points 34, 36. Accordingly, a small instrument such as the collar-button iris hook 38 can be used to urge the haptic member 32 towards the lens body 30 to thereby compress the overall length of the lens 28 to effect implantation thereof. As can be recognized, the lens 28 of Fig. 4 provides all its holding force against the interior of the eye at the four points 34, 36. By personal preference, many surgeons prefer to use the broad, sweeping arc of an open loop such as loops 18, 20 of the lens 14 of Figs. 1-3. Such loops distribute their holding forces over a broader area such that no single point is subjected to point trauma. Unfortunately, such loops, because of their design, are not adapted to the use of smaller, non-gripping implantation tools such as the collar-button iris hook 38 of Fig. 4. Such instruments just slip off the loop. Wherefore, it is the object of the present invention to provide a curved, open, strand haptic for use primarily as a superior haptic member in intraocular lenses which are adapted to be implanted through the use of small profile instruments not requiring the ability to grip the loop. Summary The foregoing object has been met in an intraocular lens having a lens body and a curved strand superior haptic member attached to the lens body on one end and free on the opposite end by the improvement comprising a discontinuity in the curve of the strand adapted to receive and hold the end of a non-gripping instrument against slipping from a compression force generally in the plane of the strand. In one embodiment, the discontinuity comprises a notch in the strand. In another embodiment, the discontinuity comprises an enlargement in the diameter of the strand. Description of the Drawings Fig. 1 is a simplified drawing showing the initial placement of the inferior loop of an intraocular lens when implanting it into the eye. Fig. 2 is a simplified drawing showing the lens of Fig. 1 and the required compression of the superior loop to effect implantation of the lens through the pupilarly opening of the eye. Fig. 3 is a more detailed drawing showing the representative sizes of the standard instruments normally required to implant the lens of Figs. 1 and 2 with respect to the environment. Fig. 4 is a drawing of a prior art lens of a type allowing the use of low-profile instruments for compression. Fig. 5 is a drawing of a superior loop of an intraocular lens according to a first embodiment of the present invention. Fig. 6 is a drawing of a superior loop 1 for an intraocular lens according to the present invention in a second embodiment thereof. Description of the Various Embodiments The improvement of the present invention 0 is to superior open haptic loops for intraocular lenses. The inferior loop can be of any type desired and forms no part of the present invention. Likewise, the shape and structure of the lens body is relatively unimportant. For purposes of this 2 description, a lens body 16, such as that shown in Figs. 1-3, is employed; A first embodiment of the present invention is shown in Fig. 5. Therein, superior loop 40, according to the present invention, is a on J " curved strand attached to the lens body 16 at 42 as by any of the well—known techniques, such as "staking". The superior loop 40 terminates on the opposite end 44 in a free end. Superior loop 40 lies substantially in the plane of the lens body 16 35 but could be angled without affecting the invention. For the purposes of the present invention, superior loop 40 includes a discontinuity in the curve of the loop 40 at location 46. In the embodiment of Fig. 5, the -> discontinuity 46 comprises a notch 48 formed into the strand 40. The notch 48 can be of any convenient shape, i.e., round, square, triangular, or circular. All that is required is that an instrument such as the collar-button iris hook 38 can be placed within or against the discontinuity 46 to allow a force to be directed against the superior loop 40 substantially in the plane of the loop 40 without slipping off the loop 40. The position of the discontinuity 46 along the length 1 of the strand 40 between the attachment point 42 and the free end 44 is determined in the same manner as the shape. The discontinuity 46 should be positioned such as to allow the strand 40 to be compressed with positive directability while 0 resisting slippage of the instrument 38 therefrom. For example, if the discontinuity 46 is placed too close adjacent the attachment point 42, an excessive force will be required to compress the loop 40 and the free end 44 will be relatively uncontrolled. In like manner, if the discontinuity 46 is placed too close to the free end 44, the compressive force required will be minimal. However, the chances of the loop 40 disengaging from the instrument 38 will be greatly increased. -If ) JU The exact placement of the discontinuity 46 will, of course, be primarily determined by the shape of the loop 40 wherein it is incorporated. A second embodiment of the present invention is shown in Fig. 6. In this example, the 5 superior loop 40' has its discontinuity 46 in the form of an enlargement 50 in the diameter of the loop strand material 40'. The enlargement 50 could be made by staking a bead onto the strand 40'. The implanting instrument to be associated with the embodiment of Fig. 6 should have a slotted end with a slot therein opening slightly wider than the diameter of the strand 40' but thinner than the enlargement 50. The slot of such an instrument could open inward from the end in the manner of a fork or come in from the side in the manner of a hook. It will be noted that both embodiments as hereinbefore described present a smooth surface to the inner periphery of the eye wherein they are disposed following implantation. This is very important inasmuch as any irregularity that can cause trauma, most likely will do so. Of the embodiments shown, the inward facing notch 48 of Fig. 5 is preferred for this very reason. Wherefore, having thus described my invention, I claim:

Claims: __ Claims 1. In an intraocular lens having a lens body and a curved strand superior haptic member 5 attached to the lens body on one end and free on the opposite end, the improvement comprising: a discontinuity in the curve of the strand adapted to receive and hold the end of a non-gripping instrument against slipping from a 0 compression force substantially in the plane of the strand. 2. The improvement to an intraocular lens superior strand haptic member of Claim 1 5 wherein: said discontinuity comprises a notch in the strand. 3. The improvement to an intraocular 0 lens superior strand haptic member ~ of Claim 1 wherein: said discontinuity comprises an enlargement in the diamter of the strand.

Inventors: LESTER JESS C, LESTER, JESS, C.
Applicants: LESTER JESS C, LESTER, JESS, C.
Application year: 1983
Main classification: A61F1
IPC codes: A61F2