Intra-Ocular Lens

This invention relates to structures for making an improved lens implant, as a replacement for a cataract-clouded or otherwise diseased natural lens. The invention represents improvement over structures described in my copending application, Ser. No. 691,033, filed May 28, 1976, now U.S. Pat. No. 4,073,014 and it employs techniques of manufacture described in my copending application Ser. No. 780,682 filed on even date herewith and now U.S. Pat. No. 4,080,709. Reference is therefore made to said applications for greater background detail as to structures and as to manufacturing technique.

Regardless of the structure of an intra-ocular lens and its mount, relatively great surgical skill is required for installation at an iris opening, if post-operative trauma is to be avoided.

It is an object of the present invention to provide improved mounting structure for an intra-ocular lens.

Another object is to provide such structure lending itself to simplified iris-stabilized installation.

A specific object is to meet the above objects with a pre-assembled lens and mount which can be operatively manipulated and installed at the end of a hypodermic needle.

Another specific object is to provide an intra-ocular lens and mount with improved tool-manipulable resiliently compliant lens-positioning feet which will automatically spring into permanent engagement with the inner side of the iris, upon tool removal.

Still another specific object is to meet the above objects with coacting lens-mount and tool structure whereby eye-filling saline solution may be introduced as the tool structure is being inserted or removed.

It is a general object to meet the above objects with a pre-assembled lens and mount and manipulative tool so as to permit safe and reliable operative installation to an iris opening with substantially less requirement for operative skill and with inherently greater assurance of trauma-free post-operative results.

Other objects and various further features of novelty and invention will be pointed out or will occur to others skilled in the art from a reading of the following specification in conjunction with the accompanying drawings. In said drawings, which show, for illustrative purposes only, preferred forms of the invention:

FIG. 1 is an enlarged view in perspective of a preassembled intra-ocular lens and mount, the same being pre-assembled to a manipulative tool;

FIG. 2 is a plan view of an undeformed blank for the mounting adapter of the pre-assembled lens and mount of FIG. 1;

FIG. 3 is a view similar to FIG. 2, after deformation and assembly to the intra-ocular lens;

FIG. 4 is a sectional view taken at 4--4 in FIG. 3;

FIG. 5 is a view similar to FIG. 1, to illustrate a different mounting-adapter in pre-assembly to the intra-ocular lens;

FIG. 6 is a plan view of an undeformed blank for part of the mounting adapter of FIG. 5;

FIG. 7 is a view similar to FIG. 6, to show two blanks of FIG. 6 in assembly to each other and to the lens;

FIG. 8 is a sectional view of the parts of FIG. 7 in pre-assembled relation to the intra-ocular lens, the section being taken at 8--8 in FIG. 7;

FIG. 9 is a perspective view of a kit package for use in effecting surgical implantation of an intra-ocular lens;

FIG. 10 is a fragmentary view in perspective to show the lens-mount engaging underside portion of the manipulative tool of FIGS. 1 and 5; and

FIGS. 11 and 12 are similar fragmentary views of modifications of the blank of FIG. 6.

In FIG. 1, an intra-ocular lens 10, which may be of suitable injection-molded plastic but which is preferably of finish-ground optical glass, is assembled to a single-piece mounting adapter 11, and the latter is removably assembled to the elongate end 12 of manipulative-tool means 13. The tool means 13 will be recognized as essentially a hypodermic needle which may be disposable and which includes at its base end a fitting 14 for removable application to a syringe 15. The mounting adapter 11 may be formed from a thin sheet of resiliently compliant material by techniques described in said copending applications and as shown comprises a first and larger pair of radially outward iris-stabilizing lens-positioning feet 16-17 at first opposed quadrant locations, and a second and smaller pair of radially outward iris-stabilizing lens-positioning feet 18-19 at the remaining opposed quadrant locations. The smaller feet 18-19 are for insertion via an iris opening and are shown to be apertured and to have been resiliently bent to one axial side of the lens-and-mount assembly, being thus retained by passage of the needle end 12 through the then-diametrically aligned openings of feet 18. It will be understood that upon longitudinal retraction of needle 12 from its engagement with the apertures of feet 18-19, the latter will naturally spring back to their normally more flat or radially outward orientation.

Turning now more particularly to FIGS. 2 to 4, the mounting adapter 11 is seen to have been initially characterized by the blank outlines of FIG. 2, being thus cut-out from sheet material by one of the photo-etch or other techniques described in said applications, and being thereafter of the appearance shown in FIG. 3 when assembled to the lens element 10. The blank of FIG. 2 comprises a circumferentially continuous centrally open body characterized for substantial conformance with and generally registering adjacency to the periphery of lens element 10, the latter being circular as shown in FIG. 3. This body is essentially a series of four integrally connected angularly spaced quadrant tabs or segments 20-21-22-23, separated by cutaway regions or slots 24-25-26-27. All tabs or segments 20-21-22-23 extend radially inward of the peripheral diameter D of lens 10 for axial-end engagement therewith, and the cutaway regions or slots 24-25-26-27 extend radially outward to at least the diameter D and preferably slightly beyond said diameter, as shown in FIG. 3. The segment 23 may be of greater radial width than its diametrically opposite counterpart 21, to permit inscription of serial number and/or lens-identifying data thereon.

The pairs 16-17 and 18-19 of iris-stabilizing feet are integral with the adapter body at the respective quadrant regions of tabs 20 to 23. For the smaller feet 18-19, the provision of tool accommodating apertures 18'-19' limits these feet essentially to outwardly bowed strips which are integrally united to segments 21-23 at angularly spaced locations, near slots 24-25 in the case of foot 18, and near slots 26-27 in the case of foot 19; such a structural relation will be understood to characterize feet 18-19 with relatively great flexible compliance for the bending needed for the tool-engagement and implant manipulation, while assuring resilient restoration to substantially radial-plane orientation upon release from tool 13. For the larger feet 16-17, a substantial economy of weight is achieved by providing apertures 16'-16" and 17'-17" which reduce these feet to essentially the bowed integral-strip nature described for feet 18-19. The openings 16'-16" and 17'-17" are separated by radius-stabilizing strips as at 28, and these openings may (as with openings 18'-19') extend radially inward to substantially the locus of the lens periphery; however, as shown, a more stiff (i.e., less flexible) integrity of feet 16-17 is assured by a greater mass of body area at segments 20-22.

It has been noted that each quadrant of the mount of FIGS. 1 to 4 is identified with a lens-engaging tab or segment and with an associated iris-stabilizing foot -- for example, the diametrically opposite larger feet 16-17 and their associated tabs 20-22 and, in angularly interlaced relation therewith, the diametrically opposite smaller feet 18-19 and their associated tabs 21-23. Fully stabilized positioning and retention of an assembled lens 10 may be realized by placing the blank over the lens, and by then resiliently bending feet 16-17 downwardly, i.e., axially away from lens 10. Such bending for the case of foot 16 will be seen to elevate tab 20 past a position of snap engagement over the adjacent peripheral region of lens 10, and the same is true, in the diametrically opposite sense, for the case of tab 22 on foot 17; subsequent release of the feet 16-17 allows feet 16-17 to spring radially outwardly, so that lens 10 is thereafter held by an axial preload via tabs 20-22 in opposition to a similar preload via tabs 21-23. Such interlaced-quadrant engagement of opposite sides of lens 10 is shown by successive dashed and solid lines of the lens periphery of FIG. 3, and it will be appreciated that in the process of establishing such axially preloaded assembly to lens 10, the feet 16-17 of one plurality are necessarily axially displaced in relation to the feet 18-19 of the other plurality, thereby providing a natural adaptation of feet 16-17 to the anterior side of the iris and of feet 18-19 to the posterior side.

While lens retention and assembly to the adapter mount of FIGS. 1 to 4 may be merely by simple assembly to the flat blank of FIG. 2, it is my preference that certain permanent bends be applied to the blank of FIG. 2 prior to lens assembly. The bends establish an axial offset .DELTA. (see FIG. 4) as between a first radial plane of segments 20-22, on the one hand, and a second radial plane of feet 16-17, on the other hand. The extent of this axial offset is preferably just short of the axial thickness of lens 10 at its engaged periphery, and this offset is essentially localized at the body regions adjacent the tab-separating slots 24-25-26-27. The net result of bending to the offset .DELTA. accounts for slight radially inward displacement of the larger feet 17, as is apparent from comparison of FIG. 3 with FIG. 2.

In the embodiment of FIGS. 5 to 8, the mounting adapter 30 for an intra-ocular lens 31 is an assembled interconnection of two halves, which may be duplicates of each other, utilizing the blank configuration of FIG. 6. As with already described structure, the embodiment of FIGS. 5 to 8 provides two apertured resiliently compliant feet 32-33 at diametrically opposed locations, for subassembly to the elongate end 12 of a manipulative tool 13. The two opposed feet 32-33 are integral formations of one of the two halves of adapter 30; the similar opposed-foot formations of the other half are identified 32'-33', and I shall continue to employ primed notation to enable differentiation between corresponding parts of one as distinguished from the other of the two assembled half elements of the mounting adapter 30.

Referring more particularly to FIG. 6, each element of the mounting adapter 30 is seen to be initially characterized by a blank of resiliently compliant sheet material, photo-etched or otherwise cut as described in said application. The blank of FIG. 6 comprises a circumferentially continuous centrally open body 34 with a circular inner edge of diameter less than the diameter D of the periphery of lens 31. The body 34 is of substantially uniform radial extent throughout and has an outer diameter D' which is substantially that of the lens 31. The apertured feet 32-33 comprise essentially outwardly bowed strips which are integrally connected at their ends to the body 34, each within its own quadrant region about a central axis. In the remaining quadrant regions, foot-engaging strips 35-36 are outwardly bowed and integrally connected at their ends to the body 34, being slightly radially offset from the adjacent segment of body 34 and defining an arcuate slot (37) therebetween. The bowed strips of feet 32-33 are locally recessed, as at 38, to define retaining detent projections 39, and the effective angular span .alpha.1 between recesses 38 of one foot (32, 33) is less than the effective angular span .alpha.2 between limits of each arcuate slot 37, while the effective angular span .alpha.3 subtended by detents 39 exceeds the slot span .alpha.2.

Referring to FIG. 7, assembly of the two elements of adapter 30 is made by orienting the feet 32-33 of one part in quadrant interlace with the feet 32'-33' of the other part. The feet 32-33 of one part are inserted through the arcuate slots 37' of the other part, and the feet 32'-33' of the other part are inserted through the arcuate slots 37 of the one part, with lens 31 interposed between bodies 34-34'; the insertions are pressed to the point of snap-lock retention at detents 38-38' at limits of the arcuate slots 37'-37. At conclusion of such snap-locked assembly, the foot-engaging strips 35-36 (35'-36') engage over and retain the inserted feet 32'-33' (32-33) and apply lens-retaining axial preload forces at the lens periphery, thereby causing a first pair of opposed feet 32-33 to be in axially offset relation with the other pair of opposed feet 32'-33'. It will be appreciated that in ultimate implanted assembly to an iris opening, these separate pairs of offset feet engage the respective anterior and posterior sides of the iris.

FIG. 9 illustrates an intra-ocular lens-implant kit of maximum convenience to the ophthalmic surgeon. The needle-tool element 40 and an assembled lens 41 and lens mount 42 are included in this kit, being shown pre-assembled to the needle-tool element 40 in readiness for removable attachment to a syringe, e.g., syringe 15. The parts 40-41-42 are shown on a shock-mounting sterile bed or cushion 43, as of urethane or the like foam, within the base of a disposable plastic case 44. Case 44 is closed by a removable clear-plastic cover 44' which normally holds the parts 40-41-42 in slight compression against the bed 43, and a dashed line 45 will be understood to be suggestive of a peripherally continuous rip strip by which the contents of a sealed and sterile package 44 can have once-only access.

FIG. 10 provides illustration of detail by means of which the needle end 12 can more usefully serve lens and lens-mount manipulation. At slightly greater than the longitudinal extent required to engage the two apertured legs 18-19 (or 32-33), the end 12 is longitudinally truncated, at 48, as along a diametral plane of the needle axis, to a radial shoulder or other stop means 49. Such truncation will be understood to provide a degree of key-engagement with adjacent adapter-mount body material, thereby providing resistance against lens-mount rotation about the needle itself. And the shoulder 49 of such truncation will be understood to axially interfere with adjacent body material of the mount, thus enabling a safe measure of axially inward manipulative thrust, without having the needle end cause damage within the posterior cavity of the eye.

FIGS. 11 and 12 illustrate slight modifications of the blank of FIG. 6 whereby manipulative effectiveness may be enhanced when used with a tool as at 13, and whereby at the same time an extended surface area is provided for inscription of serial number or other identification of the lens thereby mounted. In both cases, the extended area is provided by a chordlike edge formation in the contour of the tool-insertion opening defined by one of the outwardly bowed strips 32-33. In FIG. 11, the chordlike edge 50 spans the tool-insertion opening 51 at bowed strip 33, and in FIG. 12, the chordlike edge 52 spans the tool-insertion opening 53 at bowed strip 32. In either of these cases, a keyed engagement results between key formations 48 of tool 13 at the chordlike edge (50 or 52), provided that the needle is initially correctly assembled, and the stop or shoulder formation 49 performs the axial-insertion limitation already described.

In a typical employment of either of the general configurations of FIGS. 1 or 5, a syringe 15 loaded with saline solution is fitted to the pre-assembled tool 13 and lens and lens-mount assembly. After the customary corneal incision and removal or other disposition of the cataracted lens, the tool 13-15 is manipulated to place both of the resiliently bent feet 18-19 (32-33) behind the iris opening, retaining the remaining feet 16-17 (32'-33') in front of the iris opening. Frictional engagement of the implant with the iris may be relied upon to drag the implant as the needle end 12 is withdrawn, and the plunger of the syringe 15 may be actuated throughout the manipulative process so as to flush and fill the eye cavity with saline solution, thereby avoiding the need for a separate filling operation once the needle has been withdrawn. Of course, as the needle is withdrawn from each foot-aperture engagement, the applicable foot is released for iris-stabilizing action, against the posterior side of the iris. The needle is discarded and surgery is then completed according to customary cataract-removal procedures.

The described invention will be seen to have achieved all stated objects with structure which not only can be economically produced in substantial quantity and with great precision but which can also be constructed to such inherent lightness of weight as to enable use of the finest-finished optical-glass lenses, ground to prescription, if so required. This, of course, means greatest comfort and least danger of post-operative trauma for the patient. And the adaptability to a manipulative tool (with the moving parts) which can also provide for saline-solution injection means such a simplification of operative procedures as to permit lens-implant surgery within the manipulative-skill capabilities of vastly expanded numbers of ophthalmic technicians. Furthermore, particularly for the case of the lens-mount configuration of FIGS. 5 and 7, full and continuous circumferential overlap is provided to protect against any edge contact of a glass lens element with eye tissue, and to a limited but effective extent such protection is also afforded with the embodiment of FIGS. 1 and 3.

While the invention has been described in detail for the preferred forms shown, it will be understood that modifications may be made without departing from the scope of the invention. For example, the reference herein to a syringe will be understood to be but illustrative of, and therefore generically to describe, a manually controllable means for injecting saline solution and when needed or useful during surgery; in other words, a disposable squeeze bottle with packaged saline solution and adaptable to or embodying a disposable tool 13 may be perfect for many surgical situations and is to be understood to be within the meaning of the word "syringe" as used herein. Also, the described procedure involving tool-manipulated insertion of the intra-ocular lens and its mount may not be the procedure ultimately to be preferred for tool-insertion; for example, by using the syringe to fill and effectively float all or most of the cornea and other internal parts of the eye, it may prove most desirable to keep the needle end 12 at all times on the anterior side of the iris, relying upon manipulation of the lens-and-mount subassembly to transiently deflect iris tissue for insertion of feet 16-17 (32'-33') into the posterior region, in which case utmost protection is afforded against undue flexure of the cornea and against tool contact with any tissue.