US3074407A

US3074407A - Surgical devices for keratoplasty and methods thereof

Info

Publication number: US3074407A
Application number: US610333A
Authority: US
Inventors: Thomas E Moon; Mallick Joseph; Robert N Marshall
Original assignee: MARGUERITE BARR MOON EYE RES F
Current assignee: MARGUERITE BARR MOON EYE RES F; MARGUERITE BARR MOON EYE RESEARCH FOUNDATION Inc
Priority date: 1956-09-17
Filing date: 1956-09-17
Publication date: 1963-01-22
Anticipated expiration: 1980-01-22

Description

Jan. 22, 1963 T. E. MOON ETAL 3,

SURGICAL DEVICES FOR KERATOPLASTY AND METHODS THEREOF Filed Sept. 17, 1956 4 Sheets-Sheet 1 INVENTORS Thomas E. Moon Joseph Mullick Robert N. Marshall ATTORNEY Jan, 22, 1963 T. E. MOON ETAL. 39 3 SURGICAL DEVICES FOR KERATOPLASTY AND METHQDS THEREOF Filed Sept. 1'7, 1956 4 Sheets-Sheet 2 ANTERIOR CHAMBER VITREOUS INVENTORS Thomas E. Moon Joseph Mullick Robert N. Marshall BY il ATTORNEY Jan. 22, 1963 T. E. MOON ETAL 3,

SURGICAL DEVICES FOR KERATOPLASTY AND METHODS THEREOF Filed Sept. 17, 1956 4 Sheets-Sheet 3 FIG."

Thomas E. Moon Joseph Mullick Robert N. Marshall ATTORNEY Jan. 22, 1963 T. E. MOON ETAL 3,074,

SURGICAL DEVICES FOR KERATOPLASTY AND METHODS THEREOF Filed Sept. 17, 1956 4- Sheets-Sheet 4 FIG. 3

VII/III.

INVENTORS Thomas E. Moon Joseph Mollick Robert N. Marshall BY Z ATTORNEY United States Patent Ofiice 3,674,407. Patented Jan. 22, 1953 3,974,407 SURGICAL DEVICES FOR KERATO?LASTY AND METHODS THEREOF Thomas E. Moon, Norfolk, Va., and Joseph Maiiick, Rural Hall, and Robert N. Marshail, Winston-Salem, N.C., assignors to Marguerite Barr Moon Eye Research Foundation, Inc., Winston-Salem, N.C., a corporation of North Carolina Filed Sept. 17, 1956, Ser. No. 610,333 26 Claims. (Cl. 128303) The present invention relates to keratoplastic instruments for performing intraocular surgery and the art of keratoplasty and relates more particularly to means for performing penetrating and lamellar keratoplasty utilizing corneal transplantation or prosthetic implants.

Optical keratoplasty or corneal transplantation in which human tissue is employed, i.e. homoplasts, for penetrating transplantations comprises excision of an opacified or affected segment from the central cornea of full corneal thickness of a host eye and replacing a similar segment of clear graft cornea obtained from a human donor. The cornea may be regarded as a normally transparent window in a continuous spherically shaped, protective coat enveloping the inner structures and fluids of the eye and forming the anterior portion of the eyes fibrous tunic enabling light rays to pass to the retina within the eye. Further, the corneal tissue represents a forward continuation of the protective scleral coat and of the conjunctiva, anteriorly, and of the iris and anterior chamber, posteriorly. In meridional section it presents a number of discrete laminae including the corneal epithelium, Bowmans membrane, the substantia propria orstroma, Descemets membrane, and the endothelium.

Assuming proper psychological preparation of the patient, the classical primary requisites for successful corneal transplantation are: the excision of corneal tissue having correlative curvature or shape and topographical position, the same number of normal corneal layers and other favorable characteristics corresponding exactly as the excised opening in the host cornea with apposition of the cut edges as accurate as possible; transfer of the graft as quickly as possible, without great trauma, from the donor to the host eye; graft fixation to achieve good coaption between the cut margins of host and graft without stretching or traumatizing to prevent displacement, bulging, or tilting which would produce astigmatism; and prevention of damage to the inner orbital contents.

A trephine-like instrument for the excision of both graft and host window is conventionally employed to achieve maximum coaption between graft and host, however, the margins of each must be excised cleanly, particularly Descemets membrane. Where trephines are employed, the cutting blade must be ultrasharp to avoid separation of the corneal fibers along the circumferential line of incision and the instrument must be held exactly at right angles to the plane of the cornea. The physical nature of the cornea and the support offered by the anterior chamber often preclude clean excision of a circular disk as the cornea will tend to be displaced upon being subjected to the frictional drag of the cutting action of the trephine blade, also the cornea may tend to collapse or distort as initial partial penetration is made by a portion of the blade into the anterior chamber. Immobilization of the cornea or eyeball is extremely difficult with conventional surgical instruments. Obviously, the depth of the incision in the host eye must be carefully controlled to safeguard the iris and lens. Once the trephine is in contact with the corneal surface it must not be removed until perforation is achieved, otherwise, an irregular window or a double outline may result. Frequently upon collapse or distortion of the cornea the trephining penetration may be imperfect necessitating completion of the excision by curved corneal scissors.

Upon excision of the graft disk button, the button is deposited momentarily in a receptacle to await placement into a prepared host eye by means of a spatula or other clamping device. The host eye is suitably sutured, with the window excised by trephining, preparatory to receiving the graft corneal transplant. Each of the procedures heretofore employed potentially introduces trauma, poor coaption of the cut edges, collapse of the anterior chamber, an eccentrically positioned corneal Window, among other irregularities, since the margin for error in keratoplasty is extremely small.

Good apposition of the cut margins and a uniformly distributed pressure to prevent gapping are necessary to achieve optimum graft fixation. Graft ectasia, complete displacement, delay in the reformation of the anterior chamber, anterior synechias and hypertension are only several of the postoperative complications which may result from poor fixation.

Inadequate supply to meet increased demands for donor tissue has led to the use of artificial implantation in alloplasty with transparent prostheses. Innovations in the use of plastic implants have resulted in the perfection of several materials compatible with cornea tissue. In artificial implantation, a window substantially corresponding to the implant is trephined in the host cornea and a radial incision communicating with the window is made to facilitate the insertion of a grommet-like transparent plastic implant after which the radial incision is closed by suture. Other forms of biological windows of transparent plastic material coated on the periphery to make the window compatible with the corneal tissue have been introduced. Articulated implants have not been satisfactory and aside from protruding anteriorly and posteriorly of the cornea tissue are diflicult to maintain and have a tendency to hypertension. Frequently the formation of a membrane behind the implant results in opacification requiring replacement of the implant.

It is an object of this invention to provide a means and method for immobilizing a substantial area of corneal tissue to maintain the cornea in situ during corneal transplantation.

Yet another object of this invention is the provision of surgical apparatus for performing keratoplasty in which substantial portions of a cornea are supported to resist collapsing and displacement by means of a reduced pressure applied externally to induce the cornea to remain in normal position in the apparatus during surgery.

Another purpose of this invention comtemplates the application of a surgical apparatus in which separable corneal tissue receiving members will support a substantial area of a cornea with one member being releasably removable from the other member to remove a trephined portion of corneal tissue while supporting the remaining cornea in position.

A further object of this invention is to provide a means for supporting a cornea in situ over a substantial area while enabling an instrument to penetrate into the corneal tissue to excise a prescribed portion thereof.

Still another object of the invention is to provide a surgical apparatus for supporting a substantial area of a cornea wherein a prescribed region may be excised by means of a trephine that is supported for guided vertical penetration into the cornea for a limited extent and the excised region may be removed Without the remaining corneal tissue collapsing or being displaced.

Yet another object of this invention is to provide surgical apparatus for performing optical keratoplasty in which the cornea is supported by separable means over at least two defined areas, one consisting of that portion of the cornea which will remain in the eye and the other portion that is to be excised, a passageway of prescribed contour between the separable means to permit the introduction of a means for severing the corneal areas from each other whereby the excised portion may be removed by one member of the separable means.

A further object of the invention is the provision of a corneal trephine for keratoplasty capable of making clean and accurate excisions with minimal frictional drag and one in which the depth of tissue penetration may be limited.

It is also contemplated by this invention to provide a V surgical apparatus for corneal implantation by supporting a substantial area of the cornea surrounding a host window and means for undercutting or routing a continuous circumferentialjperiphery of the host window to form a socket preparatory for the introduction of an implant therein without enlargement of the host window either by making a radiating incision or stretching the corneal tissue.

Another object of the present invention is the provision of a transparent biological window of non-biological ma terial which is completely compatible with corneal tissue and sufficiently flexible to. be reduced in diameter for insertion, while in a contracted condition, into a routed host eye window. In accordance with this invention it is contemplated to employ an implant having a rim portion suitable for attachment in a host eye window and a center portion releasably retained in the rim portion by suitable mechanical fastening means.

Generally,'the present invention comprises a suitably supported platform having a concavity corresponding substantially to the recipient cornea contour in which concavity there is a series of concentric annular recesses between raised contoured ribs, with the recesses being interconnected to communicate with acommon central exhaust passageway leading to a suction apparatus, and a central aperture through the platform whereby a sub stantial portion of a cornea may be supported'in facial contact with the contoured ribs. A trephine supporting and guide arboryoke' housing having an axial passageway therethrough communicates with a concave reticulated end base which arbor base forms together with the,

platform a continuation of the corneal concavity with an annular passageway therebetween for introducing a hollow cylindrical inside beveled trephine blade which is supportingly guided on the arbor into the'concavity a predetermined distance to. penetrate and excise a prescribed portion of corneal tissue as the platform and arbor base retain the corneal tissue firmly in position by means of reduced pressure maintained in the arbor and the plat form recesses. Excision of the selected area of corneal tissue may be effected by releasing the arboryoke housing.

from its cooperatingpo'sition on the platform aperture.

Optimum standardization may be attained by employing complementary trephines and interchangeable apparatus for donor graft and host eye window. By substituting the donor arbor having the excised graft thereon into the platform supporting the hostv eye from which a window has been trephined and thereafter releasing the graft, the

graftwill be. correctly oriented in the ,host window with optimum apposition for-corneal transplantation. a

With artificial implanation, the platform is retained. on the host eye after the window has been trephined tov receivein combination therewith an adaptor head having a projectible surgical routing blade apparatus for under-.

cutting the peripheryof the host eye window which head comprises a housing guida-bly receivable in the platform.

aperture, a sleeve concentrically mounted and rotatable in the housing and having a blade selectively projectible into'the cylindrical wall of the host window to remove adequate tissue. therefrom to provide a socket for the reception of the cooperating periphery of an implant therein. Further, it is proposed to introduce a flexible implant into the formed corneal socket by means of an exaggerated concavity on a reticulatedend base of an arbor to reduce the diameter of a flexible implant sulficiently, upon application of adequate suction in the arbor, to orient the implant directly into the host eye socket, after which the flexible implant will be permitted to relax and expand into the socket upon release of the suction in the arbor. For some implantations an implant may be employed which has a rim portion for reception into the socket for-med in the host window with a releasable concentric center portion that may be replaced periodically in the rim portion.

Other objects and many of the attendant advantages of this invention .for performing corneal keratoplasty involving transplantation and implantation will be come more readily apparent to those skilled in this art during the course of the following detailed description taken in conjunction with the accompanying drawings wherein like characters of reference refer to corresponding parts throughout the several views, and wherein:

FIG. 1 is a front elevational view of an assembled-sun gical apparatus for corneal keratoplasty embodying the present inventiveconcept supported in a lid retractor speculum witha means for inducing a partial vacuum in the apparatus illustrated in schematic form;

FIG. 2 is'a top plan view ofFIG. 1, omitting the schematic representation of a suction inducing means;

FIG. 3 is an enlarged exploded view of thesurgical apparatus components for supporting a cornea in position and for trephining a corneal section for excision;

FIG. 4 is a greatly enlarged longitudinal sectional view, with 'sectionsremoved, illustrating the components of FIG. Sin assembled cooperative relationship;

FIG. 5 is a sectional view-of a human eye with a trephine guidably supported on an arbor per'se, as the trephine penetrates the cornea;

FIG. 6 is an enlarged bottom plan view of the cornea supporting platform; 7

FIG. 7 is a transverse sectional view taken substan tially along the plane of section line 77 of FIG. 6;

FIG. 8 is a perspective view of a corneal tissue undercutting instrument;-

FIG. 9 is a side elevational view of the undercutting instrument of FIG. 8;

FIG. 10 is a transverse sectional view of the cutting instrument taken substantially along the plane of section line 10-40 of FIG. 9;

FIG. 11 is an exploded view of the component's of the cutting head instrument in juxtaposition with a cornea supporting platform;

FIG. 12 is. a top plan view of a flexible implant disk;

FIG. 13 is a transverse diametral sectional view of the- FIG. 16 is a transverse sectional view takenv substantially along the plane. of section line -1616 of FIG. 15. Referring to the drawings, and more-particularly to FIGS. 1 and 2, there is illustrated. an assembled apparatus 10 for performing corneal keratoplasty' adjustably mounted on a modified blepharostat 11 or comparable supporting. lid retracting speculum which will bear on The longitudinal arms 12 and 13 are laterally spaced'from each other'by' slidably displacing the arm 13 having transverse arm rethe bridge of the nose and zygoma.

ceiving sleeves 14 and locking screws 15 thereon from" the arm 12 from which the

transverse arms

16,17 and18 extend. A pair of opposed arcuate lid 'retractors 19 extend downwardly to maintain wide retraction of the lidswithout pressure on the eye globe. A platform engaging saddle 24} extends between the

arms

17 and 18 for trans verse slidable adjustment thereon and locking engage-' ment by meansof thelocking screw 21. The offsetten I minal ends of the arms 12 and 13 are provided with adjusting screws 22 against which ends the pivotable fingers 23 may rest when positioned against the zygoma and the other terminal end of the arm 12 is provided with an adjusting screw 24 against which the pivotable finger 25 may rest when positioned on the nose bridge.

Cornea Platform The cylindrical outer shell 28 of the cornea receiving platform 29 is releasably mounted in the saddle 20 as by friction or other suitable means, with a trephine supporting arbor yoke or housing 30 cooperatively engaged with in the platform, as more clearly shown in FIG. 4. Platform 29, as shown in FIGS. 3, 4, 6, 7 and 11, for receiving a substantial surface of the cornea has an outer shell 28 in which are located indexing and locking openings 31 adjacent to the upper edge thereof. A cornea contoured chamber or concavity 32 is formed in the base of the platform interior which concave chamber resembles a truncated spherical segment with a central orifice or aperture 33 formed at the crest thereof. Vertically spaced concentric circumferential recesses 34 having progressively reduced diameters are formed in the wall of the contoured concavity. Cornea engaging concentric annular ribs 35' project outwardly to form the surface contact with a cornea. An exhaust passageway or tube 36 is fastened, as by soldering, to communicate with the individual openings 37 into which the circumferential recesses 34 may be evacuated. A flexible tubing 38, having a helical wire spring 39 extending therein to prevent the flexible tube from collapsing, is fastened to the end of the tube 36 with the other end of the tubing being connected to a conventional suction pump apparatus 40 from which a partial pressure may be accurately maintained to effect a uniform suction within all of the concentric recesses 34. With controlled evacuation, the platform concavity will retain, by corneal tissue contact with the ribs 35 and the slight sealing protrusion of the tissue in the recesses, a substantial area of the cornea in position and preclude tissue mobility. The cylindrical wall of the central aperture 33, in the embodiment illustrated, is accurately machined, with close tolerance, at right angles to the horizontal plane of a cornea to guidably receive a trephine or other instrument therein. The top 41 of the base surrounding the orifice 33 is accurately machined to provide a continuous limiting shoulder against which a surgical instrument, such as a trephine, may be located when in the operative cutting position, to be described hereinafter.

Trephine and Arbor Housing The trephine arbor and housing assembly 30 comprises a cylindrical shell having enlarged openings 42 through the shell to provide finger access to the central axial hollow trephine supporting arbor 43. The top end 44 of the housing will support the arbor at one end, as by soldering or other suitable fastening means, to permit the arbor to extend axially without added support. A skirt 45 at the other end of the housing, integral with the longitudinal shell elements 46, is undercut sufiiciently to form a shoulder 47 and a platform engaging rim 48. An arcuate resilient release and locking leaf spring 49 is fastened intermediate its length to the inner wall of the skirt and has radially projecting fastening lugs 50 mounted adjacent to the spring ends at the bottom edge thereof to project, in extended condition, through the openings 51 in the skirt 45 and the openings 31 in the platform when the spring is in the relaxed condition. Plungers 52 mounted adjacent to the upper edge of the spring 49 and adjacent to the ends thereof extend outwardly through the housing for radial movement to retract the lugs 50 into the housing thereby releasing the housing assembly {0 from the platform when the plungers 52 are pressed nwardly.

The hollow arbor 43 extends axially for a predetermined length which, as clearly shown in FIG. 4, terminates in a concave end plug or base member 55. The curvature of the arbor base member 55 will complement and complete the corneal concavity in the platform 29 when the housing assembly is in cooperative engagement with the platform. Arbor base member 55 is provided with openings 56 therein that communicate with the hollow passageway 57 in the arbor 43. It is contemplated that a rigid reticulated surface having the requisite contour and opening therethrough may be employed. An annular clearance 58 is provided between the outer periphery of the arbor and the inner periphery of the aperture 33 through which a cutting blade of a trephine may be introduced into the concavity below. A trephine supporting lug 59 is mounted on the arbor adjacent to the top thereof for a purpose to be described hereinafter.

It will be readily apparent that upon connecting a flexible tube 60, having a helical Wire 61 therein to preclude tube collapse, to a suction device 62, the central portion 63 of a cornea 64 may be immobilized as by clinging engagement with the surface of the concave arbor end plug 55, as shown in FIG. 5.

T rephine A hollow cylindrical trephine 65 preferably having a knurled surface is supported in the inoperative position on the lug 59 mounted to the arbor 43 through the bayonet fastening slot 66 at the upper end of the trephine. The cutting section 67 of the trephine is undercut from the cylindrical surface of the trephine body to provide a depth limiting shoulder 68. Shoulder 68 will normally engage the bearing surface 41 on the top of the platform aperture 33 in the final projected operative cutting position to limit the depth of blade penetration. The outer surface of the hollow cutting blade section 67 is cylindrical throughout its length to the cutting edge 70. The interior of the blade has an inside divergent bevel 71 tapering toward the cutting edge 70. It has been found that an included angle which includes the inclined edges of the blade of approximately 20 degrees is suitable, however, deviations may be made as this specific angle does not appear to be absolutely critical. This inclined beveled inner surface is accurately ground and honed to produce an ultra-sharp cutting edge.

The overall length of the cylindrical blade 67 is very accurately calibrated and although it is preferred that in dividually calibrated trephines be employed for each specific penetration, it is also contemplated that calibrated spacer rings, such as ring 73, may be mounted on the blade and frictionally held thereon against the shoulder 68 for contact with the platform surface 41. It is also contemplated that various micrometer adjusting means may be employed in place of the ring spacers either on the trephine per se or in conjunction with the top surface 41 of the platform.

It has been determined that the internal bevel on the cutting blade reduces tensions and trauma to corneal tissue which are normally inherent in excising either graft or host tissue as well as reduces frictional drag which is normally appreciable in the conventional external beveled trephine. Further, the cylindrical exterior wall presents a smooth surface for guided and supported projection within the cylindrical wall of the aperture 33.

It is proposed that the overall thickness of the cornea be very accurately measured either by the ophthalmoscope or the slitlamp in normal opacification of the cornea with the application of specialized techniques of Stallard or Maurice and Giordini in cases of dense opacification. To completely safeguard the lens and iris, it is recommended that a trephine of the exact blade length be employed, without external compensation, for full blade depth penetration.

In general the trend is toward grafts 5 to 7 mm. in diameter and depending upon the particular surgical preference and experience. Some surgeons prefer a difference of 0.1 mm. between graft and host window to allow for postoperative swelling and avoidance of protruding graft margin. Shelvingis also conventional in graft and host margins. However, in view of the standardized accuracy of trephining for both graft and host window by utilizing this trephine in combination with the platform and arbor support apparatus and the minimum time requirements to perform the operation, identical diameter trephines may be used with excellent apposition obtained in transplantation.

. One preferred method of employing the apparatus of this invention is to utilize identically matched or mating pairs of components to facilitate interchangeability. After preoperative preparation including corneal depth measurement and trephine selection, the corneal platforms 29 are mounted in position over a supported donor eye and also over a host eye. The platform exhaust passageways are connected to suction producing devices to maintain the corneas of the respective eyes in position. The trephine and arbor assembly for each apparatus is cooperatively seated by having the'lugs 50 register within the indexing openings in the platform with the trephines 65 in the retracted inoperative position, as illustrated clearly in FIGS. 1 and 4. With the trephine and arbor assembly mounted in position, the requisite controlled suction is applied to the, arbor end plug through the passageway 57 by means of a second suction producing apparatus or when con- 9 face 41. Upon completion of the corneal penetration,

the trephine is replaced in the inoperative position and the members are disenaged by depressing the plunger buttons andthe trephine and arbor assembly may then be raised vertically with the excised graft aflixed to the arbor end plug.

After a determination that the donor graft is acceptable, in all respects, the host window may then be formed in substantially the same manner as described above. Then, the graft assembly is remounted and locked in indexed relation on the host platform after which the graft may be deposited in position in the host window either by releasing the suction pressure in the arbor or applying a slight positive pressure therein to break the seal formed between the graft and the end plug. When necessary the graft may be sutured in the host window and conventional postoperative carema'y commence.

Corneal Undercuftz'ng Apparatus for Implantation In FIGS. 8 through llthere is illustrated apparatus for forming a. circumferential rout or undercut in the corneal tissue of a host'window prepared initially by trephining as described above for the formation of an implant retaining socket. The cutter head 80-is intended for application in combination with the platform 29. The head comprises, a concentrically bored housing 81 having an axial bore 82 with a platform receiving cylindrical shaft 83 and a depth limiting flange 84. A bushing 85 having an eccentrically drilled sleeve receiving opening 86 with a flange 87 at one end and a cylindrical shaft 88 ,at the other end is received within the bore 82 for rotation therein. A tubular sleeve 89 extends through the eccentrically bored opening 86 in the bushing. Threaded stud 90 receives a pair of cooperating dished

segmental cutter elements

91 and 92, each of which elements hasa studreceiving opening 93- therein. The cutter elements are mounted, on the stud against the stud head 94to form, when assembled, an open channel V-notch cutting blade 95, as shown in FIGS. 8through 10. The bottom cutting.

element'92 is countersunk sufficiently to permit the head 94 to be mounted at least flush with the exterior 'of the cutter; A knurled knob 96'thr'eadably engages the 'op- S. posite end of the stud 90 to retain the components in assembled relationship.

In operation, after the host window has been formed with a cylindrical wall by means of the trephine 65 and the trephine and arbor housing is released and separated from the platform 29, with the platform remaining in position to retain the corneal tissue in situ, the cutter head is inserted therein, with the cutter blade 95 retracted, into the orifice 33 with the shaft 83 engaging the cylindrical wall of the orifice and the bottom face of the flange 84 resting against the top surface 41 of the platform surrounding the aperture 33. Withthe cutter head 80 seated in the platform 29, knurled knob 96 is slowly rotated approximately degrees, for a full depth cut, to project the cutter blade from the position shown in FIG. 10 to the position illustrated in FIG. 9, thereby introducing the V-notch blade into the cylindrical wall of the host eye. By rotation of the knurled knob a short segment of tissue will enter the .V-notch channel 97 to commence the undercut. Flange 87 on bushing 85 is next rotated a complete revolution to revolve the blade 95 in the oriented projected position to complete the formation of a V-notch socket in the host window. The tissue routed from the cornea will be retained in the channel 97. Upon completion of the socket in the host eye, the knob 96 is rotated back to its original position to retractthe blade 95, with the tissue still retained therein. The cutter head 80 is then removed vertically from within the platform recess. For cleaning and sterilization the cutting instrument head may be disassembled as shown in FIG. 11. Platform 29 with suction applied thereto is still retained on the cornea until an implant has been introduced into the host window socket.

Implants In view of the many limitations inherent in living tissue, various introductions have been attempted to provide a transplant window of non-biological materials, such as quartz, resins, glass and other plastic materials. which are compatible or may be made compatible with living tissue by treating the non-biological material with a suitable coating material in selected areas. Frequently, a deposit or membrane may be formed on the posterior of the implant in the anterior chamber so as to cloud the artificial window and removal of the implant is neces-' sary for cleansing purposes.

In FIGS. 12 through 14, there is illustrated one embodiment of a dimensionally stable artificial circular concavo-convexo transparent implant 100 which may be molded or machined to the desired configuration with the Conventionally it is necessary to make a radial incision into the cornea surrounding the host window which will communicate with the host window in order to enlarge the opening to introduce an implant which will normally have a diameter larger than the base host window. After the implant is in position the incision is then sutured.

The implant 100. is to be formed of a plastic material, such as acrylic, methacrylate, or other suitable materials which are sufli ciently pliable or flexible so that upon suboriginal diameter and contour will be achieved upon releasing the suction effect on the implant and the implanb will then be firmly seated in the host eye socket. Suitable v tolerances and clearances between implant and socket will be determined by surgical experience. Anchoring the implant during the postoperative period will be conventional by utilizing overlying sutures or other methods.

For introducing the flexible integral implant 100, it is proposed to utilize the platform 29 throughout the entire operation to support the cornea. However, a modified arbor housing having a more acutely concaved end plug 105, fragmentarily shown in FIG. 14, inserted in the hollow arbor 106 in which plug openings 107 will conduct a suction action sufficient to support the implant 109 thereon and flex or distort it sufiiciently to the desired concavity conforming to the surface configuration of the plug 105. With the implant 100 on the end plug, the arbor housing may be connected to the platform 29 thereby orienting the implant to the host eye socket. Upon release of the suction in the arbor the implant will expand and seat itself into the socket.

In FIGS. 15 and 16 there is shown a modified concavo-convexo sectional transparent implant 119 of the requisite contour having a rim portion 111 with a V- beveled periphery 112 which will correspond substantially to the socket V-notch cut in a host window. A plurality of suture openings 113 are circumferentially spaced about the rim for anchoring the rim in position upon implant introduction to the host eye socket. A concentric center insert plug 114 is releasably fastened by means of a cooperating airtight and liquid sealing threaded connection 115 formed in the inner periphery of the rim portion and the outer periphery of the plug. Spaced surface indentations 116 on the plug 114 will accommodate a spanner wrench for insertion and removal of the plug. It will be apparent that other types of airtight and fluid sealing fastening connections may be utilized in place of the threaded connections as well as means for insertion and removing the plug into the rim. It is further contemplated that the modified implant will be sufiiciently flexible to be inserted by means of the apparatus described for the introduction of the integral implant 160 by orienting the suture openings away from the openings in the hollow arbor end plug. Furthermore, a suction tube may be employed to insert or remove the insert plug 114 from its socket in the rim portion.

Upon completion of the implantation, as well as periodically, it may be necessary to remove the insert plug 114 for cleansing the posterior thereof or for replacement. This may be readily accomplished with the assistance of the platform 29 which will support the remaining portion of the cornea in place. A flexible plug may also be utilized in combination with a routed notch opening in the rim portion in a manner described above for the integral implant 110.

Obviously, many modifications and variations may be made in the construction and arrangement of the suction platform for supporting a substantial area of the corneal tissue, the releasable trephine support and arbor housing, the surgical cutting instrument head and the implants, as well as the other elements constituting the combination assemblage in light of the above teachings without departing from the real spirit and purpose of this invention. Further, although the apparatus has been described primarily for application in corneal keratoplasty, it is not intended in any limitative sense for precluding the application of this apparatus with modifications, to analogous surgical operations. It is, therefore, to be understood that within the scope of the appended claims many modified forms of structure as well as the use of mechanical equivalents may be reasonably included and modifications are contemplated.

What is claimed is:

1. A surgical instrument for keratoplasty for removing a defined area of corneal tissue comprising, in combination, a platform having a cornea contoured receiving concave wall, said concave wall having recesses therein,

an exhaust passageway communicating with said recesses, means for producing a suction in said passageway and said recesses to support a cornea against the concave wall, said platform having an aperture therethrough, a trephine supporting and corneal disk removing arbor releasably mounted on the platform, said arbor having central passageway and a contoured corneal disk supporting base member at one end with an opening therein, said central passageway communicating with the base member opening, said passageway being connected to said suction producing means to maintain the corneal disk in situ by contact with the base member during severance, a trephine guidably supported on the arbor for vertical displacement from an inoperative to an operative position for insertion into a cornea about the arbor and through said aperture, and means for limiting trephine penetration into the cornea and whereby upon severance of the corneal disk the disk may be removed upon disengagement of trephine supporting and corneal disk removing arbor from the platform.

'2. Surgical apparatus of the character described comprising, in combination, a cornea receiving platform having an aperture therein, said platform having an irregular surface with means associated therewith for generating a reduced pressure within the platform to maintain a cornea introduced therein in situ, a trephine supporting arbor releasably connected to the platform in juxtaposition with the platform aperture forming an annular opening between said arbor and said aperture, said arbor having a passageway and means for supporting a portion of a cornea in situ thereon, a hollow cylindrical trephine mounted for vertical guided movement on the ar-bor for limited penetration into the annular opening to excise a selected portion of a cornea supported by the platform and the arbor.

3. A surgical apparatus for corneal transplantation comprising, in combination, a platform having a contoured cornea-receiving concavity and a trephine-receiving aperture therethrough for engaging a substantial area of a cornea, said platform having indentations within the concavity, means for generating a suction pressure in said indentations to maintain a cornea in situ, a corneal disk removing hollow arbor cooperatively insertable into and releasably supported on the platform aperture, said arbor having at one end a contoured plug for cooperation with and to complement the platform concavity, and a trephine guidably supported on the arbor for guided vertical displacement between the arbor and the trephine-receiving aperture of the platform into a cornea.

4. A surgical apparatus for keratoplasty comprising, in combination, a platform having a concave cornea receiving chamber, said chamber having means for subjecting the chamber to a reduced pressure to retain a cornea in surface contact with the chamber surface, said chamber having an orifice therein, an arbor having a complementary contoured surface and means for subjecting the surface to a reduced pressure to retain an additional corneal surface in situ relative to the remaining cornea surface, said arbor and platform being releasably engaged in operative position and forming an annular cavity therebetween with the arbor in juxtaposition in the orifice, a trephine having a cutting blade mounted on the arbor for displacement into the annular cavity to penetrate into the cornea receiving chamber to excise a selected corneal area, and means to limit trephine blade penetration.

5. A surgical apparatus for keratoplasty comprising, in combination, a platform having a concave cornea receiving wall with concentric circumferential recesses therein and a central aperture therethrough, an exhaust passageway communicating with the recesses to apply a uniform suction therein for supporting a substantial area of a cor nea in situ, said aperture having a cylindrical wall and a level exterior surface opposite from the concave wall, a

trephine and arbor supporting housing releasably engageable to the platform in indexed relation, said housing including an arbor having a passageway therein and an arbor cornea disk supporting contoured plug at one end supported in the housing, said plug having an opening therein communicating with the arbor passageway with the plug contour complementing the platform concavity, said arbor in juxtaposition with the cylindrical wall of the aperture forming an annular passageway therebetween, a trephine guidably supported on the arbor, means for releasably retaining the trephine in an inoperative position on the arbor, said trephine having a hollow cylindrical blade for insertion into said annular passageway and also having means for limiting trephine penetration into the cavity in the operative position to excise a window in a cornea.

6. A surgical apparatus for corneal keratoplasty comprising, in combination, a platform having a cornea contoured chamber with concentric circumferential recesses therein forming raised cornea contacting ribs and a central aperture through said platform, an exhaust passageway communicating with said recesses whereby upon subjecting the passageway to a reduced pressure a cornea will be maintained in situ against the chamber ribs exposing a selected cornea portion in said aperture, said aperture having a cylindrical Wall and a level exterior surface opposite from the contoured chamber, a trephine and arbor supporting housing releasably engaga-ble with the platform in indexed relation, said housing including an arbor having a passageway therein and an arbor cornea disk supporting concave plug at one end of the arbor, said concave plug having a complementary contour for insertion into the aperture of the platform chamber and also having a reticulated surface with openings communicating with the arbor passageway, said arbor and said aperture forming in juxtaposition an annular passageway therebetween, a trephine having a cutting blade at one end guidably mounted on the arbor for dis placement from an inoperative to an operative position, means for releasably locking the trephine in an inoperative position on the arbor, said trephine having a limit stop thereon for engaging said level exterior surface of the platform upon penetration of the cutting blade into the annular cavity in sliding guided contact with the cylindrical Wall of the aperture, additionally said trephine cutting blade being provided with an internal bevel tapering to a cutting edge on said blade whereby upon rotation of the trephine the selected cornea portion may be exised and completely removed upon separation of the housing from the platform.

7. A surgical apparatus for corneal keratoplasty comprising, in combination, a lid retracting speculum, a platform having a cornea contoured chamber adjustably mounted on the speculum, said chamber having a wall with concentric circumferential recesses therein forming a plurality of cornea contacting ribs and a central aperture through said platform, an exhaust passageway communicating with said recesseswhereby upon subjecting the passageway to a reduced pressure a cornea will be maintained in situ against the chamber wall ribs exposing a selected cornea portion in said aperture, said aperture having a cylindrical wall and a level exterior surface opposite from the contoured chamber, a trephine and an arbor supporting housing releasably engagable with the platform in indexed relation, said housing including an arbor having a passageway therein and an arbor cornea disk supporting concave plug at one end of the arbor, said concave plug having a contour for insertion into the aperture of the platform chamber complementary to the platform chamber contour and also having a reticulated surface with an opening communicating with the arbor passageway, said arbor and saidaperture forming in juxtaposition an annular passageway therebetween, a trephine having a cutting blade at one end guideably mounted on the arbor for displacement from an inoperative to an operative position, means for releasably locking the trephine in an inoperative position on the arbor,

said trephine having a limit stop thereon for engaging said level exterior surface of the platformupon penetration of the cutting blade into the annular cavityin sliding guided contact with the cylindrical wall of the aperture, additionally said trephine cutting blade being provided with an internal bevel tapering to a cutting edge on said blade whereby upon rotation of the trephine the selected cornea portion may be excised and completely removed upon separation of the housing from the platform.

8. A surgical platform of the character described for supporting a substantial area of a cornea in situ therein comprising a chamber having a cornea-shaped concave Wall and a trephine-receiving orifice therethrough at a selected position, said wall having recesses therein, means for evacuating the chamber through the wall recesses to support corneal tissue in surface contact with the chamber wall. v

9. A surgical platform of the character described fo supporting a substantial area of tissue in situ therein comprisinga concave chamber having. a contour wall corresponding substantially to the tissue contour to be introduced therein, .said chamber having means therein for applying a suction action thereto to support the tissue in. surface contact with the chamber wall, said wall having: at least one indentationfor admitting the flow of air therearound to support the tissue in situ, said. chamber: also having a trephine-receiving circular aperture in. a selected position in the contour wall to expose a'port'ion of the supported tissue for removal through said aperture.

10. A surgical platform of the character described for maintaining a substantial area of, corneal tissue insitu. comprising a cornea-receiving chamber having a concave configuration substantially identical to a cornea to be, received therein, said chamber having a wall, saidrwall having a plurality of spaced apart concentric recesses means for subjecting the wall recesses to a vacuum to maintain the tissue in surface contact therewith said Wall having a trephine-receiving opening in a selected portion to ex pose a portion of the corneal tissue. I v,

11. A surgical platform for immobilizing and supporting in situ a tissue mass such as a cornea comprising a concave chamber having'an internal contoured chamber similar to the normal, contour of a cornea to be retained' therein, said chamber having a plurality of spaced apart. openings in the surface thereof, an exhaust passageway communicating with each of the openings in the'chamber for subjecting the openings to a reduced pressure ,ade quate to support and maintain a cornea in situ during trephining upon connecting the exhaust passageway, to a vacuum generating apparatus.

12. A surgical platform for immobilizing and sup porting in situ a corneal tissue of substantial area said platform having a chamber with a concave profile contour similar to a cornea for the reception of same therein, a plurality of concentric annular cavities in the chamber and protruding ribs therebetween, a trephine-receiving aperture in said platform to expose a portion of the cornea to be excised, an exhaust passageway communicating with each of the annular cavities whereby upon subjecting the exhaust passageway to a vacuum apparatus a cornea may be firmly maintained in surface contact with the ribs and seal the annular cavities within the chamber.

13. In combination, an arbor having a hollow coreand an outer cylindrical bearing surface, a corneal trephine slidably mounted on said arbor, said trephine comprising a hollow cylindrical body having at one end a depth penetration limiting external shoulder and, in axial spaced relation thereto, a projecting cutting blade and circular edge slidably mounted on the arbor, the outer surface of said cutting blade being cylindrical and the holl-ow interior of said. cutting blade having a gradual conical bevel to the cutting edge, the length of said bevel being at least the thickness of the cornea tissue to be cut 13 with the conical bevel remote from the cutting edge terminating at a position intermediate the cutting edge and the shoulder.

14. In combination, an arbor having a hollow core and an outer cylindrical surface, a corneal trephine of the character described, said trephine being slidably and releasably mounted on the arbor, said trephine having a hollow cylindrical body having at one end a depth limiting shoulder and an undercut cylindrical projecting cutting blade, said blade having an internal divergent bevel tapering toward the outer cylindrical wall to form a circular cutting edge, said cutting edge being in spaced relation to the arbor cylindrical surface.

15. In a surgical instrument for severing a corneal disk from a cornea, the combination of a trephine supporting hollow arbor, said arbor having means for releasably locking a trephine in an inoperative position, a cylindrical trephine slidably retained on said arbor and having means for receiving said arbor locking means at one end, said trephine also having a continuous circular cylindrical blade at the other end and a stop shoulder in spaced relation to the blade to limit blade penetration into a cornea.

16. The art of excising and transplanting corneal tissue comprising the steps of supporting a cornea in situ over a substantially large surface area to prevent cornea mobility and collapse, trephining a selected area of the cornea while in the supported immobile condition and Within the supported area, removing a defined corneal section, replacing the removed corneal section with a similarly defined corneal section from another cornea while maintaining the trephined cornea in situ.

17. The art of excising and transplanting corneal tissue comprising the steps of subjecting corneal tissue to a confined reduced pressure over a substantially large surface area to maintain the corneal tissue in situ without collapsing, subjecting a defined smaller area of a portion of corneal tissue to be excised to a confined reduced pressure, cutting the corneal tissue while in the supported condition to excise the portion to be removed from the remaining corneal tissue, excising the cut smaller area, replacing the removed corneal section with graft tissue having a similarly \defined configuration as the excised tissue while maintaining the corneal tissue in situ.

18. The method of corneal transplantation comprising the steps of subjecting corneal tissue to a reduced pressure over a substantially large surface area to prevent cornea mobility and place an extensive area of the cornea against a solid surface, subjecting a defined central area of a pontion of corneal tissue to be removed to a reduced pressure to support the central area in situ, trephining the corneal tissue while in the supported condition to excise the central defined portion from the remaining portion of the cornea, replacing the removed corneal section with a similarly defined corneal section from another cornea while maintaining the trephined cornea in situ, and subjecting the replacement corneal section to a positive pressure to deposit the corneal section in apposition with the cornea.

19. The art of removing a defined area of corneal tissue to form a host window and preparing the Window for the introduction of a corneal implant comprising the steps of subjecting corneal tissue to a reduced pressure over a substantial area to immobilize the corneal tissue, subjecting a defined smaller area outside of the larger area to be excised to a confined reduced pressure, to immobilize it, cutting the corneal tissue while in the immobilized condition, excising the defined smaller area to form a host eye window while retaining the remaining corneal tissue in situ, and routing the corneal tissue remaining intermediate its depth to form an implant socket, and inserting a corneal implant into the implant socket.

20. In combination, apparatus for intraocular surgery on a cornea comprising a platform having a cornea contoured chamber wall, said concave chamber wall having means in communication therewith to draw corneal tissue into engagement with said wall and maintain the tissue in situ after a host window has been formed in the tissue, said platform chamber wall having an opening guidably introducing and cooperatively and releasably supporting an adaptor cutting head thereon, said cutting head including a shaft rotatably mounted in the head, and a routing cutting blade transversely projectible to undercut the host window and retractible out of the undercut, and means on the cutter head for rotating said shaft whereby the blade will rout a socket in the host window.

21. Apparatus for use in keratoplastic implantation of a cornea comprising, in combination, a platform having a cornea contoured concave chamber, means for subjecting the chamber to a reduced pressure to support and maintain a cornea in situ, said chamber having an orifice extending therethrough for introducing an instrument into the chamber after a selected portion of a cornea has been excised to form a circular opening in the corneal tissue, an expandible cornea cutting instrument cooperatively received and supported in the orifice, said instrument comprising a rotatable shaft, a blade mounted on the shaft for cutting operation transverse to the shaft axis, and means for rotating the shaft and blade.

22. A surgical cutting instrument for undercutting a cornea by providing a corneal host window for the reception of a corneal implant subsequent to the removal of a corneal disk, in combination, a cornea contoured receiving platform having a concave cornea-receiving chamber adapted to be connected to .a suction apparatus for maintaining a suction over a substantial area of the chamber to retain a cornea in situ, said platform having an instrument receiving opening therein, an implant socket forming instrument having a housing releasably mounted and slidably inserted in the platform receiving opening, said housing having a cylindrical axial bore and a shoulder thereon for limiting the depth of instrument penetration into the opening, a bushing having an eccentrically bored opening therethrough rotatably supported in said housing, means for rotating said bushing in the housing bore, a shaft rotatably mounted in the eccentrically bored opening and having a cutting blade mounted at one end to undercut a circumferential groove intermediate the [depth of a host eye cornea, said shaft having a means for projecting and retracting the blade into and out of cutting position whereby upon projection of the blade and rotation of the bushing a circumferential groove may be cut in the host eye window to form a socket therein.

23. In combination with a cornea-supporting platfrom having an opening therein, a corneal tissue undercutting instrument guidably supported in the platform opening and comprising a cylindrical insert for slidable cooperation with the platform instrument opening, means on the instrument for limiting the depth of insertion into the platform opening, a rotatable shaft having a cutting blade at one end for undercutting an opening in a cornea, means at the other end of the shaft for radially rotating the shaft and blade, and means for presenting said blade from a non-cutting retracted inoperative position to a cutting operative position.

24. An implant eye surgical instrument for use in combination with a cornea-supporting platform having an aperture for guidably receiving and supporting said instrument, said instrument comprising a housing for slidable insertion and support in the platform aperture, said housing having a cylindrical axial bore and a shoulder thereon for limiting the depth of housing penetration, a bushing rotatably receiving in the housing bore, said bushing having an eccentric opening therein and means for rotating the bushing, a shaft having a segmental cutting blade mounted at one end thereof to undercut a circumferential opening in corneal tissue, said shaft having means for presenting said blade from a non-cutting retracted position to a cutting operative position, said cutting blade including a pair of dished opposed segments forming a V- 15 notch channel for routing a socket in the corneal tissue. "25. In combination, a cylindrical hollow arbor, and a corneal trephine of the character described slidably mounted thereon, said trephine comprising a hollow cylindrical body having at one end a projecting cylindrical blade with a continuous circular cutting edge normal to the axisof the cylindrical body said blade having an internal. bevel said. cutting edge and the arbor forming an annular cavity therebetween.

26. In combination, a surgical platform for supporting a substantial area of a cornea in situ, said platform having a chamber with acornea-shaped concave wall and an orifice therein, and a hollow cylindrical arbor supported thereon, at-rephine havinga hollow cylindrical body with aprojecting circular cutting blade at one end slidably mounted on the arbor, the outer surface of said cutting blade being cooperatively received and rotatable in said platform orifice, said cutting blade having a hollow interior and an internal bevel.

References. Cited in the file of this patent H UNITED STATES PATENTS 7 1,279,495 Dom Sept. 24, 1918 1% Sutherland Apr. 7, 1925 Blair Nov. 19, 1929 Green Apr. 25, 1933 Bard Mar..7, .1939 Longoria July 22, 1941 Zinkil Nov. 23, 1943 Turkel Aug. 26, 1947 Paton June 21, 1949 Jayle Aug. 30, 1949 Karle Apr. 11, 1950 Batchelder, Aug. 1, 195.0. Crossley May 29, 1951 Kadesky -1..- May 27, 1952 Zenatti May 24, 1955 Stone Aug. 9, 1955 Brochetti Apr. 8, 1958 Ara June 10, 1958 FOREIGN PATENTS Great Britain Feb. 8, 1911