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Selective Cryoextraction of the Cataractous Lens*
SELECTIVE CRYOEXTRACTION OF THE CATARACTOUS LENS* GEORGE M.
HAIK,
M.D.,
GEORGE S.
ELUS,
M.D.,
A N D J O E L B.
POLLARD,
M.D.
New Orleans, Louisiana
The past four years have witnessed a remarkable resurgence of interest in the use of low temperature in ocular therapeutics. This renaissance, beginning with the work of Krwawicz in 1961, has spread and appears to create new interest each day. In the recent literature on intraocular cryosurgery, Sudarsky and his associates2 call attention to the use of cold sources, chiefly in the form of carbon dioxide snow, for basic research on the effects of rapid freezing on the cornea,3'4 the ciliary body,5 choroid and retina.6'7 Small series of clinical cases have also been reported in which this method was used for glaucoma,8"10 retinal detachments,11 prolapse of the iris12 and herpes simplex.13 Since Krwawicz's first re port in 1961 on the management of cataracts by cryosurgery14 and his second in 1963," the number of operations on record has reached several hundred. While this paper was in preparation, 55 new cases were re ported in two articles in the British litera ture,1'16 200 were reported from the Russian literature,17 128 were reported from Ger many18 and Bellows brought his personal and personally supervised operations up to 165.10 The purpose of this presentation is to re port our results with cryosurgery in the ex traction of the cataractous lens, the only condition for which we have, as yet, used this method. It seems to offer considerable promise in retinal detachments, and we pro pose shortly to undertake studies with it in that field. Preliminary reports on its use in glaucoma do not, however, encourage us to pursue its potentialities in that disease, in which our experience with another modality, * From the Department of Ophthalmology, Louisiana State University School of Medicine. Presented at the 101st annual meeting of the American Ophthalmological Society, Hot Springs, Virginia, May, 1965. 484
beta radiation, also produced only tempo rary results.19 EQUIPMENT FOR CRYOGENIC INTRAOCULAR SURGERY
Cooper's20 description of the physical fac tors that effect the rate of transfer of heat in cryosurgery of the brain are generally applicable to intraocular cryotherapy. They include, he points out, the surface area of the freezing tip; the temperature and rate of flow of the cooling agent that passes through the tip; and the thickness and the capacity for heat of the metal wall of the noninsulated portion of the cannula. He lists the important biologic factors as : ( 1 ) the coefficient of heat, (2) the thermal diffusibility of the tissue and (3) the radius of the lesion to be produced. In intraocular surgery, the radius of the lesion to be pro duced would correspond to the so-called cold ball produced by freezing of the cataractous lens. All of the instruments devised for in traocular cryosurgery are based on these physical and biologic factors. Sudarsky and his associates have com mented in some detail on the biophysical mechanisms involved in cryotherapy. They studied human lenses in vitro using the Coo per cryogenic apparatus, and concluded that different parameters exist for the surface adhesive effect and the penetrating effect of the cold. They noted that the depth to which the lens substance is fused is a function of the temperature of the probe and the thermal conductivities of the various tissues. The optimum cohesive effect occurs between — 3°C and — 75°C. Below this temperature an increasingly weak cohesion is noted which is probably due to an intrinsic change in the structure of the ice bond. Between — 3°C and — 18°C, surface cohesion occurs and
CRYOEXTRACTION OF CATARACT within 45 seconds the ice mass extends into the cortex but not into the nucleus. This is called the cortical phase. Below — 20°C, in most cases, 45 seconds after application, the ice mass will extend deep enough to entrap the nucleus. This "nuclear phase" exists be tween - 2 0 ° C and - 7 5 ° C . Below - 7 5 ° C , the depth of penetration continues to increase but the surface bond become weaker. Thus, temperatures below — 75°C are of little or no value in cryoextraction of the lens but can be utilized for other types of ocular sur gery, such as retinal detachments in which the deeper penetration is necessary to pro duce an adhesive chorioretinitis.
485
contained, but it seems heavy and cumber some. The two instruments devised by Bel lows10'22 have undergone several modifica tions. One of them was originally cooled by fragmented solid carbon dioxide, which has since been replaced by commercially available highly pressurized carbon di oxide contained in small metal cylinders. The other instrument is cooled by liquid ni trogen, which is introduced by way of a sep arate filling unit. Both instruments have de frosting elements which can be brought into immediate use if the tip of the probe comes into contact with tissues other than the lens. Kelman's 21 first cataract extractions by Both of these instruments seem ingenious cryosurgery, at St. Barnabas' Hospital in and of the delicacy appropriate to ophthal New York, were done with the instrument mic surgery. They are readily sterilized, can Cooper used for surgery of the thalamus. be transported easily and are apparently as Kelman found the liquid nitrogen system simple to use as an erisophake. They have, cumbersome for eye work and eventually however, the obvious disadvantage of re replaced it with an instrument of his own quiring electrical connections. design, the cryostylet. This thermoelectric The instrument (fig. 1) recently introduced instrument requires only tap water and elec by Sudarsky and his associates,2·23 for cryo tricity. It uses no cooling or refrigerating surgery of the eye and used by us in our 36 agent. It consists of three parts : ( 1 ) the in cataract extractions in private practice (fig. strument itself, (2) the power supply and 1) consists of a light-weight plastic holder, (3) a pump and reservoir. In spite of its 150-cm long and 3.5-cm in diameter. The efficiency, this is not a simple instrument container has a screw top at one end. At the and its initial cost is quite high. other end, which is tapered, is a small block The cryoextractor described by Krwawicz of silver covered with copper (the heat in 196114 was cooled by a mixture of solid sink), from which a silver probe protrudes carbon dioxide and methyl alcohol. It was for about eight mm. In the container are a an efficient instrument but it had obvious number of carefully calculated evaporation disadvantages. When it was removed from spaces, and about the cold block is a space the cooling agent and used at room tempera or reservoir for the liquefied gas. ture, it heated up so rapidly that the surgeon The cooling agent, liquid Freon 22, is put had only a limited time in which to extract up in standard aerosol cans. When the can the cataract. Its insulation was such, Con1 is inserted into the container and the top way pointed out, that the cornea or iris screwed on, the resulting pressure forces might be accidently touched and adhere to 18 the discharge valve of the can against the the cold metal above the tip. Davies' work cold block and enough Freon is discharged was done with the Krwawicz extractor, but he used industrial methylated spirit B.P. in to fill the reservoir about it. As the gas evaporates through the spaces provided for stead of methyl alcohol.1 1 this purpose, it is replenished from the can The instrument that Conway devised is at a steady rate, and the heat sink and prorefrigerated by liquid nitrogen. It is self-
486
GEORGE M. HAIK, GEORGE S. ELLIS AND JOEL B. POLLARD
Fig. 1 (Haik, Ellis and Pollard). The Sudarsky instrument.
truding probe are maintained at a tempera ture of about —41°C. The Sudarsky instrument weighs 130 gm when loaded and 62 gm when empty. The steadily decreasing weight, as the contained Freon gas is used up, is sometimes discon certing when the instrument is first used. The technique is very simple. The tip of the cryoextractor is held at an angle of 60 degrees, just as one would hold a pencil. When the surgeon activates the instrument by screwing the top on, frost appears on the tip, usually in about 20 seconds, and extrac tion can proceed at once, on the assumption that the desired temperature has been achieved. This instrument has decided advantages. Its structure is simple. It is entirely selfcontained. It operates without electrical, hy draulic or gaseous connections. It is readily sterilized by ethylene oxide, and it can be stored in the sterile state for an indefinite time so that it is ready for use whenever it is needed. A series of 68 consecutive extractions was performed with the cryoextractor de vised by Dr. Dean Larson, senior resident in ophthalmology, on the Louisiana State University School of Medicine Service at Charity Hospital of Louisiana at New Or leans, concurrently with a series of 36 ex tractions performed on our private service at Hotel Dieu Hospital with the Sudarksy instrument. The Larson instrument consists of (1) a removable outer plastic insulator, 15-cm long and 18 mm in diameter, which is open at one end; (2) a thin copper tube with an outside diameter of 12 mm, which leaves an insulating
space between it and the container of about 3 mm ; and, (3) a conducting silver rod, 2.5 mm in diameter, which extends through the copper tube and protrudes externally for about 2.5 mm. The rod is slightly tapered at the end, where its diameter is reduced to 2 mm. When the copper tube is filled with pulverized dry ice, which is readily available commercially, supercooling (to — 79°C) is achieved in about 60 seconds. The plastic container is gassterilized and the metal components are autoclaved. The Larson instrument has all the advan tages just listed for the Sudarsky instru ment. Both instruments are much less ex pensive than some of the others that have been devised for cryosurgery of the eye. EXPERIMENTAL STUDIES
For the most part, our experimental work has been designed to perfect our technique of cryoextraction. Using rabbit and pig eyes, however, we have also attempted to determine the depth of penetration of the ice ball in the lens with the Sudarksy instru ment (Freon gas), the Larson instrument (dry ice), and the Kelman instrument (or dinary tap water). Our studies, which were admittedly rath er crude, showed that the cold produced by the Kelman cryostylet penetrated the cap sule and cortex of the lens only super ficially. With both of the other instru ments the cold penetrated the lens tissues for about half their depth. The bond ob tained with both of these instruments also seemed somewhat stronger than that ob tained with the Kelman instrument, and it was somewhat more difficult experimentally to release them from the iris, cornea and other tissues or from suture material that had been allowed to become adherent to them. Experimentally as well as clinically, the Kelman instrument, although theoretic cally more efficient, did not seem to produce results with its defroster that were in any way superior to those produced by simple irrigation with tap water in releasing tissues
CRYOEXTRACTION OF CATARACT
that had accidentally become adherent to the extractor. INDICATIONS FOR CRYOEXTRACTION OF CATARACTS
There is general agreement that intracapsular extraction is a far more desirable cata ract operation than the extracapsular proce dure. It is not always admitted, or even real ized, that the intracapsular procedure is del icate and difficult, even for the most experi enced ophthalmic surgeons. Moreover, when the capsule is torn, as it sometimes is even in the most expert hands, the capsule and lens may not be removed in toto. Incomplete removal gives rise to a number of possible complications, including formation of a sec ondary membrane, postoperative infection and phacoanaphylactic endophthalmitis.24 Whether cryosurgery will eliminate most, or even some, of the problems of cataract extraction it is too soon to say with assur ance but the outlook seems promising. In our own private practice we are still using this new technique with a high degree of selectivity, and to date we have employed it in only 36 cases, though it should be added that if we had been able to obtain all the supplies of Freon that we needed, our series would be larger by 20 cases or more. Our present indications are : 1. Subluxated lens* In this condition, it is necessary to exert some degree of force while the lens is grasped with the forceps or * The definition of the term subluxation is generally misunderstood. The connotation of the term varies from person to person. From the surgical standpoint, the distinction between subluxation and luxation is usually that the former is an incomplete process while the latter is a complete separation of the lens from the zonules and other structures that normally hold it in position. For surgical purposes, in our opinion, the most practical distinction is that a subluxated lens is one which, even though it may be dis placed, remains in the pupillary aperture, with the vitreous intact. A luxated lens is one which is completely displaced from its normal anatomic position and is associated with a rupture of the vitreous."
487
the erisophake, and, no matter how gently this maneuver is carried out, the vitreous may be pushed out of its normal location and some of it may be lost. 2. Intumescent lens. When the capsule is so tense that it is impossible to grasp it with forceps, the erisophake must be used, and again, no matter how gentle the manipula tions, the suction created may tear the cap sule. 3. Hypermature cataract. When a hypermature cataract is associated with a thin capsule, the risk of capsular tear is always present, no matter what instrument is used. 4. Certain traumatic cataracts. If rupture of the capsule is part of the traumatic pro cess, it is difficult to remove all of the cap sule and lens material with either the for ceps or the erisophake, and we have found cryoextraction useful in such cases. There are, of course, other indications. Bellows10 lists intumescent cataracts and some luxated cataracts associated with glau coma, cataracts associated with fluid vitre ous, and cataracts in monocular patients. TECHNIQUE
The initial steps of cryoextraction are those of the standard operation, using a limbal-based flap. Certain precautions are nec essary. The corneoscleral incision must be a full 180 degrees. If a complete sector iridectomy is not performed, the iris must be re tracted at 12 o'clock in order to expose a larger portion of lens capsule. Finally, one must be certain that the loops of the preplaced sutures and the conjunctival flap are out of the way. We do not use the enzymat ic technique. Once the cryoextractor has been turned on, the cornea is lifted and the iris is re tracted. The tip of the probe is placed over the center of the lens, care being taken that the exposed portion of the probe does not touch the posterior surface of the cornea, the iris or the sutures. The lens is gently rocked from side to side, while the zonules are ruptured by external pressure over the
488
GEORGE M. HAIK, GEORGE S. ELLIS AND JOEL B. POLLARD
limbal area at the 6-o'clock position. The lens is then slowly lifted from its bed by a combination of traction and pressure. If during this maneuver the iris, the cornea or any of the suture material should come in contact with the exposed tip of the probe, separation can be readily accomplished by irrigation with warm physiologic salt solu tion or distilled water. The remainder of the operation is performed by the usual tech nique. One other technical point might be men tioned. It is sometimes wise to use only two or three preplaced sutures to lessen the chance of their being caught by the probe. If additional sutures are needed, they can be placed after the lens is delivered. RESULTS
In the light of what has been said, it is evident that cryoextraction has certain ad vantages over the usual technique of cata ract extraction : 1. Because only minimal pressure is nec essary, the risk to the capsule is greatly re duced and intracapsular extraction can usu ally be accomplished. 2. Similarly, the risk of vitreous loss is greatly reduced. 3. If the capsule should be accidentally torn during the classical extraction opera tion, it is often possible to hold the cryoextractor over the tear and complete the proce dure by the intracapsular technique. These advantages are borne out by the results achieved with this technique. We have had no capsular ruptures in the 36 op erations on our private service done with the Sudarsky instrument, and there were only two ruptures in the 68 operations done at Charity Hospital with the Larson instru ment. The reported experience is similar. Conway1 had only one capsular rupture in 30 operations for senile cataracts and blamed himself for the accident, which was caused by premature traction with the cryoextractor. Bellows10 had no ruptures in the 150 extractions which he performed per
sonally, and there were none in the 15 oper ations done by his residents under his direc tion and supervision. Rosengren18 reported 14 ruptures in 128 operations and frankly attributed the number to the fact that five surgeons, all of them inexperienced in this technique, performed the operations. This group used zonulolysis routinely, whereas Krwawicz, whose technique they followed otherwise, used it only in patients under 60 years of age. Even more important than the low inci dence of capsular rupture is the low rate of vitreous loss when this technique is used. There was no loss in any of our 36 private operations and loss in only two of the 68 operations performed at Charity Hospital. Again, these good results are borne out by those reported in the literature. There was no loss of vitreous in any of Conway's 30 operations,1 and loss occurred in only four of the 128 operations performed by Rosen gren and his group. 18 These results are, of course, what might be anticipated for several reasons : 1. The cryoextractor is applied to the lens under full vision. 2. In the standard intracapsular extrac tion, the capsule is called upon to sustain a considerable weight. With cryosurgery, the traction is transmitted over the frozen cap sule and lens. Kelman and Cooper21 demon strated that when the capsule was held with forceps, it ruptured when a weight of 7.5 gm was applied, whereas it sustained weights up to 250 gm with the cryoextractor at - 2 0 ° C . 3. Cryoextraction is particularly desirable in subluxations. In the last two such cases which we handled with the Sudarsky instru ment, it was possible to avoid the trauma of pinning in both. COMPLICATIONS
Possible complications during cryoextrac tion include damage to the cornea, damage to the iris and vitreous adhesions. Our com bined experience in New Orleans, which is
CRYOEXTRACTION OF CATARACT
borne out by the published data, suggests that these complications can readily be avoided and that they are neither frequent nor serious. Complications in our 36 private cases were as follows : In one instance, the cryoextractor became adherent to the cornea and remained adher ent for five or six seconds. Separation was readily accomplished by irrigation with warm saline solution, and at the end of two weeks the cornea seemed entirely normal. In several other cases in which the instru ment became adherent to the iris, separation was difficult in only one instance. In that case we were somewhat slow in accomplish ing the separation and the iris finally had to be pulled away from the cryoextractor. The immediate result was an irregular pupillary tear, with an area of iris atrophy. The final result was merely a slight pupillary irregu larity. There was no interference with vi sion. In one case in which a subluxated lens lay beneath the iris in the lower nasal quadrant, the tip of the cryoextractor was necessarily placed over the edge of the lens and vitreous became adherent to the posterior surface of the lens as extraction was being accom plished. We had no difficulty in washing the vitreous away from the lens, and it retracted into its normal cavity without any loss. It was not until a similar situation developed in another case when the extractor was ap plied to the upper pole of the lens that we realized that we were freezing the vitreous as well as as the lens. As in the first case, separation was accomplished without loss of vitreous. Visual results in our private series met our expectations in every instance. In the Charity Hospital series, results were equally good except in one case, in which a poor re sult had been anticipated because of persis tent glaucoma caused by pre-existing trau matic angle recession. 812 Maison Blanche Building
(70112).
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REFERENCES
1. Conway, J. : Preliminary report of cataract extraction by freezing. Brit. J. Ophth., 49:141, 1965. 2. Sudarsky, R. D., Hulquist, R., and Chi, H. H. : Cryogenically induced iris atrophy, iridectomy and cataract in rabbits. Am. J. Ophth., 60:217, 1965. 3. Maumenee, A. E., and Kornblueth, W. : Regen eration of corneal stormal cells: II. Review of literature and histologie study. Am. J. Ophth., 32:1051, 1949. 4. Dunnington, J. H. : Some modern concepts of ocular wound healing. Arch. Ophth., 59:315, 1958. 5. Bietti, G. : Surgical intervention on the cili ary body; new trends for the relief of glaucoma. JAMA, 142:889, 1950. 6. Deutschmann, R. Cited by Sudarsky et al.a 7. Bietti, G. B. Cited by Sudarsky et al.2 8. Polack, F. M., and de Roetth, A., Jr. : Effect of freezing on the ciliary body (Cyclocryotherapy). Invest. Ophth., 3 :164, 1964. 9. McLean, J. M., and Lincoff, H. A. : Cryosurgery of the ciliary body. Tr. Am. Ophth. Soc, 62 :385, 1964. 10. Bellows, J. G. : Indications and technique of cryoextraction of cataracts. Arch. Ophth., 73:476, 1965. 11. Lincoff, H. A., McLean, J. M., and Nano, H. : Cryosurgical treatment of retinal detachment. Tr. Am. Acad. Ophth., 68:412, 1964. 12. Kelman, C. D. : Cryosurgery for cataract extraction and the treatment of other eye dis eases. Highlights Ophth., 7 :181, 1964. 13. Krwawicz, T. : Cryogenic treatment of herpes simplex keratitis. Brit. J. Ophth., 49:37, 1965. 14. Krwawicz, T. : Intracapsular extraction of intumescent cataract by application of low tem perature. Brit. J. Ophth., 45 :279, 1961. 15. : Further experience with intracapsu lar cataract extraction by application of low tem perature. Brit. J. Ophth., 47:36, 1963. 16. Davies, T. G. : Intracapsular cataract ex traction using low temperature. Brit. J. Ophth., 49:137,1965. 17. Chutko, M. B., and Zumbulidze, G. D. : Cryogenic method of cataract extraction. Vestnik Oftal., 77 :24, 1964. Abstract JAMA, 191:190 (adv. sect.), Feb. 22, 1965. 18. Rosengren, B. : Cataract extraction by means of the cryoextractor according to Krwa wicz. Tr. Ophth. Soc. U. Kingdom, 84:275, 1964. 19. Haik, G. M., Breffeilh, L. A., and Barber, A. : Beta irradiation as a possible therapeutic agent in glaucoma: An experimental study with the report of a clinical case. Am. J. Ophth., 31:945, 1948. 20. Cooper, I. S. : A cryogenic method for physiologic inhibition and production of lesions in the brain. J. Neurosurg., 19 :853, 1962. 21. Kelman, C. D., and Cooper, I. S. : Cryogen-
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GEORGE M. HAIK, GEORGE S. ELLIS AND JOEL B. POLLARD
ic ophthalmic surgery. Am. J. Ophth., 56:731, 1963. 22. Bellows, J. G. : Cryo-extraction of cata racts. Highlights Ophth., 7:114, 1964. 23. Sudarsky, R. D., and Hulquist, R. : Biophy sical aspects and instrumentation in ocular cryosurgery. In press. 24. Haik, G. M, Waugh, R. L., Jr., and Lyda, W. :
Sympathetic ophthalmia. Similarity to bilateral endophthalmitis phacoanaphylactica : New thera peutic methods. Arch. Ophth., 47:437, 1952. 25. Haik, G. M., Kalil, H. H., Ferry, J. F., and Childers, M. D. : Subluxations and luxations of the lens: With a special note on the Barraquer operation and on Marian's and Marchesani's syn dromes. South. M. J., 54:642, 1961.
T H E CLOSURE O F VERTICAL LID LACERATIONS* A N D T H E REPAIR OF VERTICAL LID CICATRICES E D M U N D B.
SPAETH,
M.D.
Philadelphia, Pennsylvania
cause of that a vertical laceration of the con junctiva is not complicated but a deep hori zontal one definitely is. One sees the same effect to a convincing degree in the ptosis of cervical-sympathetic paralysis. The levator tendon also has a significant effect upon a through-and-through lid lac eration. The levator tendon, if still function ing, widens a vertical laceration, in the upper lid, as the orbicularis fibers pull the two cut surfaces farther apart into an in verted V, the closer to the midline the lac eration the wider the gaping of the wound * From The Graduate Hospital of the Graduate (fig. 2). School of Medicine, University of Pennsylvania. The mechanics of defects from lacera This paper was presented before the Section of Ophthalmology, Philadelphia College of Physi tions of the lower lid are not too dissimilar. cians, March, 1965. The normal lid attachments to the fascial This paper is dedicated to a distinguished and beloved member of this Section, recently de sheath of the inferior rectus muscle and the ceased, Dr. Alfred Cowan, emeritus professor of connections of this to the lower lid and to ophthalmology, The Graduate School of Medicine the septum orbitale limit the gaping of a of the University of Pennsylvania. Some achieve greatness through the drive of great genius, laceration of the lower lid in the midline. others reach that through the fortune of an Eli- This anatomic anchor, however, combined jah-Elisha relationship,1 but Dr. Cowan attained with the downward pull of the facial mus the pinnacle because of his intellect, his impecca ble integrity and his consistently human aspect to cles of expression and the separating orbic all things professional and cultural. There is no ularis fibers, causes a gaping of a lower lid wonder that we who knew him loved him. Dr. laceration when the wound is in the outer Cowan was a clinician, as his books and many papers demonstrate, and he was happiest when in third or the inner third of the lower lid. vestigating disease and working with patients. It This is different from the tendency for is proper, therefore, that this paper, in memory of him, be clinical. The subject is chosen deliber upper lid midline lacerations to separate ately for he referred to me my first serious widely (figs. 3 and 4). ophthalmic plastic surgery problem in civilian life These are the conditions which modify for he knew that I had had these cases thrust upon me while I was in the military service. I the primary repair of injuries of the lids. am proud that I can pay Dr. Cowan homage this They apply also to the primary closure of evening. colobomas in the midline of the upper lid,
Before discussing the aspects of closure of vertical lid lacerations and repair of ver tical lid cicatrices, a brief review of the anatomy of the lids significant to the subject will help to explain why poor cosmetic re sults are not uncommon. The orbicularis muscle fibers form a sphincter, adherent through the canthal liga ments (fig. 1) to the lateral and medial edges of the orbit. The Müller muscle fibers in the superior cul-de-sac are adherent to the conjunctiva of the superior fornix. Be-
HAIK,
M.D.,
GEORGE S.
ELUS,
M.D.,
A N D J O E L B.
POLLARD,
M.D.
New Orleans, Louisiana
The past four years have witnessed a remarkable resurgence of interest in the use of low temperature in ocular therapeutics. This renaissance, beginning with the work of Krwawicz in 1961, has spread and appears to create new interest each day. In the recent literature on intraocular cryosurgery, Sudarsky and his associates2 call attention to the use of cold sources, chiefly in the form of carbon dioxide snow, for basic research on the effects of rapid freezing on the cornea,3'4 the ciliary body,5 choroid and retina.6'7 Small series of clinical cases have also been reported in which this method was used for glaucoma,8"10 retinal detachments,11 prolapse of the iris12 and herpes simplex.13 Since Krwawicz's first re port in 1961 on the management of cataracts by cryosurgery14 and his second in 1963," the number of operations on record has reached several hundred. While this paper was in preparation, 55 new cases were re ported in two articles in the British litera ture,1'16 200 were reported from the Russian literature,17 128 were reported from Ger many18 and Bellows brought his personal and personally supervised operations up to 165.10 The purpose of this presentation is to re port our results with cryosurgery in the ex traction of the cataractous lens, the only condition for which we have, as yet, used this method. It seems to offer considerable promise in retinal detachments, and we pro pose shortly to undertake studies with it in that field. Preliminary reports on its use in glaucoma do not, however, encourage us to pursue its potentialities in that disease, in which our experience with another modality, * From the Department of Ophthalmology, Louisiana State University School of Medicine. Presented at the 101st annual meeting of the American Ophthalmological Society, Hot Springs, Virginia, May, 1965. 484
beta radiation, also produced only tempo rary results.19 EQUIPMENT FOR CRYOGENIC INTRAOCULAR SURGERY
Cooper's20 description of the physical fac tors that effect the rate of transfer of heat in cryosurgery of the brain are generally applicable to intraocular cryotherapy. They include, he points out, the surface area of the freezing tip; the temperature and rate of flow of the cooling agent that passes through the tip; and the thickness and the capacity for heat of the metal wall of the noninsulated portion of the cannula. He lists the important biologic factors as : ( 1 ) the coefficient of heat, (2) the thermal diffusibility of the tissue and (3) the radius of the lesion to be produced. In intraocular surgery, the radius of the lesion to be pro duced would correspond to the so-called cold ball produced by freezing of the cataractous lens. All of the instruments devised for in traocular cryosurgery are based on these physical and biologic factors. Sudarsky and his associates have com mented in some detail on the biophysical mechanisms involved in cryotherapy. They studied human lenses in vitro using the Coo per cryogenic apparatus, and concluded that different parameters exist for the surface adhesive effect and the penetrating effect of the cold. They noted that the depth to which the lens substance is fused is a function of the temperature of the probe and the thermal conductivities of the various tissues. The optimum cohesive effect occurs between — 3°C and — 75°C. Below this temperature an increasingly weak cohesion is noted which is probably due to an intrinsic change in the structure of the ice bond. Between — 3°C and — 18°C, surface cohesion occurs and
CRYOEXTRACTION OF CATARACT within 45 seconds the ice mass extends into the cortex but not into the nucleus. This is called the cortical phase. Below — 20°C, in most cases, 45 seconds after application, the ice mass will extend deep enough to entrap the nucleus. This "nuclear phase" exists be tween - 2 0 ° C and - 7 5 ° C . Below - 7 5 ° C , the depth of penetration continues to increase but the surface bond become weaker. Thus, temperatures below — 75°C are of little or no value in cryoextraction of the lens but can be utilized for other types of ocular sur gery, such as retinal detachments in which the deeper penetration is necessary to pro duce an adhesive chorioretinitis.
485
contained, but it seems heavy and cumber some. The two instruments devised by Bel lows10'22 have undergone several modifica tions. One of them was originally cooled by fragmented solid carbon dioxide, which has since been replaced by commercially available highly pressurized carbon di oxide contained in small metal cylinders. The other instrument is cooled by liquid ni trogen, which is introduced by way of a sep arate filling unit. Both instruments have de frosting elements which can be brought into immediate use if the tip of the probe comes into contact with tissues other than the lens. Kelman's 21 first cataract extractions by Both of these instruments seem ingenious cryosurgery, at St. Barnabas' Hospital in and of the delicacy appropriate to ophthal New York, were done with the instrument mic surgery. They are readily sterilized, can Cooper used for surgery of the thalamus. be transported easily and are apparently as Kelman found the liquid nitrogen system simple to use as an erisophake. They have, cumbersome for eye work and eventually however, the obvious disadvantage of re replaced it with an instrument of his own quiring electrical connections. design, the cryostylet. This thermoelectric The instrument (fig. 1) recently introduced instrument requires only tap water and elec by Sudarsky and his associates,2·23 for cryo tricity. It uses no cooling or refrigerating surgery of the eye and used by us in our 36 agent. It consists of three parts : ( 1 ) the in cataract extractions in private practice (fig. strument itself, (2) the power supply and 1) consists of a light-weight plastic holder, (3) a pump and reservoir. In spite of its 150-cm long and 3.5-cm in diameter. The efficiency, this is not a simple instrument container has a screw top at one end. At the and its initial cost is quite high. other end, which is tapered, is a small block The cryoextractor described by Krwawicz of silver covered with copper (the heat in 196114 was cooled by a mixture of solid sink), from which a silver probe protrudes carbon dioxide and methyl alcohol. It was for about eight mm. In the container are a an efficient instrument but it had obvious number of carefully calculated evaporation disadvantages. When it was removed from spaces, and about the cold block is a space the cooling agent and used at room tempera or reservoir for the liquefied gas. ture, it heated up so rapidly that the surgeon The cooling agent, liquid Freon 22, is put had only a limited time in which to extract up in standard aerosol cans. When the can the cataract. Its insulation was such, Con1 is inserted into the container and the top way pointed out, that the cornea or iris screwed on, the resulting pressure forces might be accidently touched and adhere to 18 the discharge valve of the can against the the cold metal above the tip. Davies' work cold block and enough Freon is discharged was done with the Krwawicz extractor, but he used industrial methylated spirit B.P. in to fill the reservoir about it. As the gas evaporates through the spaces provided for stead of methyl alcohol.1 1 this purpose, it is replenished from the can The instrument that Conway devised is at a steady rate, and the heat sink and prorefrigerated by liquid nitrogen. It is self-
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GEORGE M. HAIK, GEORGE S. ELLIS AND JOEL B. POLLARD
Fig. 1 (Haik, Ellis and Pollard). The Sudarsky instrument.
truding probe are maintained at a tempera ture of about —41°C. The Sudarsky instrument weighs 130 gm when loaded and 62 gm when empty. The steadily decreasing weight, as the contained Freon gas is used up, is sometimes discon certing when the instrument is first used. The technique is very simple. The tip of the cryoextractor is held at an angle of 60 degrees, just as one would hold a pencil. When the surgeon activates the instrument by screwing the top on, frost appears on the tip, usually in about 20 seconds, and extrac tion can proceed at once, on the assumption that the desired temperature has been achieved. This instrument has decided advantages. Its structure is simple. It is entirely selfcontained. It operates without electrical, hy draulic or gaseous connections. It is readily sterilized by ethylene oxide, and it can be stored in the sterile state for an indefinite time so that it is ready for use whenever it is needed. A series of 68 consecutive extractions was performed with the cryoextractor de vised by Dr. Dean Larson, senior resident in ophthalmology, on the Louisiana State University School of Medicine Service at Charity Hospital of Louisiana at New Or leans, concurrently with a series of 36 ex tractions performed on our private service at Hotel Dieu Hospital with the Sudarksy instrument. The Larson instrument consists of (1) a removable outer plastic insulator, 15-cm long and 18 mm in diameter, which is open at one end; (2) a thin copper tube with an outside diameter of 12 mm, which leaves an insulating
space between it and the container of about 3 mm ; and, (3) a conducting silver rod, 2.5 mm in diameter, which extends through the copper tube and protrudes externally for about 2.5 mm. The rod is slightly tapered at the end, where its diameter is reduced to 2 mm. When the copper tube is filled with pulverized dry ice, which is readily available commercially, supercooling (to — 79°C) is achieved in about 60 seconds. The plastic container is gassterilized and the metal components are autoclaved. The Larson instrument has all the advan tages just listed for the Sudarsky instru ment. Both instruments are much less ex pensive than some of the others that have been devised for cryosurgery of the eye. EXPERIMENTAL STUDIES
For the most part, our experimental work has been designed to perfect our technique of cryoextraction. Using rabbit and pig eyes, however, we have also attempted to determine the depth of penetration of the ice ball in the lens with the Sudarksy instru ment (Freon gas), the Larson instrument (dry ice), and the Kelman instrument (or dinary tap water). Our studies, which were admittedly rath er crude, showed that the cold produced by the Kelman cryostylet penetrated the cap sule and cortex of the lens only super ficially. With both of the other instru ments the cold penetrated the lens tissues for about half their depth. The bond ob tained with both of these instruments also seemed somewhat stronger than that ob tained with the Kelman instrument, and it was somewhat more difficult experimentally to release them from the iris, cornea and other tissues or from suture material that had been allowed to become adherent to them. Experimentally as well as clinically, the Kelman instrument, although theoretic cally more efficient, did not seem to produce results with its defroster that were in any way superior to those produced by simple irrigation with tap water in releasing tissues
CRYOEXTRACTION OF CATARACT
that had accidentally become adherent to the extractor. INDICATIONS FOR CRYOEXTRACTION OF CATARACTS
There is general agreement that intracapsular extraction is a far more desirable cata ract operation than the extracapsular proce dure. It is not always admitted, or even real ized, that the intracapsular procedure is del icate and difficult, even for the most experi enced ophthalmic surgeons. Moreover, when the capsule is torn, as it sometimes is even in the most expert hands, the capsule and lens may not be removed in toto. Incomplete removal gives rise to a number of possible complications, including formation of a sec ondary membrane, postoperative infection and phacoanaphylactic endophthalmitis.24 Whether cryosurgery will eliminate most, or even some, of the problems of cataract extraction it is too soon to say with assur ance but the outlook seems promising. In our own private practice we are still using this new technique with a high degree of selectivity, and to date we have employed it in only 36 cases, though it should be added that if we had been able to obtain all the supplies of Freon that we needed, our series would be larger by 20 cases or more. Our present indications are : 1. Subluxated lens* In this condition, it is necessary to exert some degree of force while the lens is grasped with the forceps or * The definition of the term subluxation is generally misunderstood. The connotation of the term varies from person to person. From the surgical standpoint, the distinction between subluxation and luxation is usually that the former is an incomplete process while the latter is a complete separation of the lens from the zonules and other structures that normally hold it in position. For surgical purposes, in our opinion, the most practical distinction is that a subluxated lens is one which, even though it may be dis placed, remains in the pupillary aperture, with the vitreous intact. A luxated lens is one which is completely displaced from its normal anatomic position and is associated with a rupture of the vitreous."
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the erisophake, and, no matter how gently this maneuver is carried out, the vitreous may be pushed out of its normal location and some of it may be lost. 2. Intumescent lens. When the capsule is so tense that it is impossible to grasp it with forceps, the erisophake must be used, and again, no matter how gentle the manipula tions, the suction created may tear the cap sule. 3. Hypermature cataract. When a hypermature cataract is associated with a thin capsule, the risk of capsular tear is always present, no matter what instrument is used. 4. Certain traumatic cataracts. If rupture of the capsule is part of the traumatic pro cess, it is difficult to remove all of the cap sule and lens material with either the for ceps or the erisophake, and we have found cryoextraction useful in such cases. There are, of course, other indications. Bellows10 lists intumescent cataracts and some luxated cataracts associated with glau coma, cataracts associated with fluid vitre ous, and cataracts in monocular patients. TECHNIQUE
The initial steps of cryoextraction are those of the standard operation, using a limbal-based flap. Certain precautions are nec essary. The corneoscleral incision must be a full 180 degrees. If a complete sector iridectomy is not performed, the iris must be re tracted at 12 o'clock in order to expose a larger portion of lens capsule. Finally, one must be certain that the loops of the preplaced sutures and the conjunctival flap are out of the way. We do not use the enzymat ic technique. Once the cryoextractor has been turned on, the cornea is lifted and the iris is re tracted. The tip of the probe is placed over the center of the lens, care being taken that the exposed portion of the probe does not touch the posterior surface of the cornea, the iris or the sutures. The lens is gently rocked from side to side, while the zonules are ruptured by external pressure over the
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GEORGE M. HAIK, GEORGE S. ELLIS AND JOEL B. POLLARD
limbal area at the 6-o'clock position. The lens is then slowly lifted from its bed by a combination of traction and pressure. If during this maneuver the iris, the cornea or any of the suture material should come in contact with the exposed tip of the probe, separation can be readily accomplished by irrigation with warm physiologic salt solu tion or distilled water. The remainder of the operation is performed by the usual tech nique. One other technical point might be men tioned. It is sometimes wise to use only two or three preplaced sutures to lessen the chance of their being caught by the probe. If additional sutures are needed, they can be placed after the lens is delivered. RESULTS
In the light of what has been said, it is evident that cryoextraction has certain ad vantages over the usual technique of cata ract extraction : 1. Because only minimal pressure is nec essary, the risk to the capsule is greatly re duced and intracapsular extraction can usu ally be accomplished. 2. Similarly, the risk of vitreous loss is greatly reduced. 3. If the capsule should be accidentally torn during the classical extraction opera tion, it is often possible to hold the cryoextractor over the tear and complete the proce dure by the intracapsular technique. These advantages are borne out by the results achieved with this technique. We have had no capsular ruptures in the 36 op erations on our private service done with the Sudarsky instrument, and there were only two ruptures in the 68 operations done at Charity Hospital with the Larson instru ment. The reported experience is similar. Conway1 had only one capsular rupture in 30 operations for senile cataracts and blamed himself for the accident, which was caused by premature traction with the cryoextractor. Bellows10 had no ruptures in the 150 extractions which he performed per
sonally, and there were none in the 15 oper ations done by his residents under his direc tion and supervision. Rosengren18 reported 14 ruptures in 128 operations and frankly attributed the number to the fact that five surgeons, all of them inexperienced in this technique, performed the operations. This group used zonulolysis routinely, whereas Krwawicz, whose technique they followed otherwise, used it only in patients under 60 years of age. Even more important than the low inci dence of capsular rupture is the low rate of vitreous loss when this technique is used. There was no loss in any of our 36 private operations and loss in only two of the 68 operations performed at Charity Hospital. Again, these good results are borne out by those reported in the literature. There was no loss of vitreous in any of Conway's 30 operations,1 and loss occurred in only four of the 128 operations performed by Rosen gren and his group. 18 These results are, of course, what might be anticipated for several reasons : 1. The cryoextractor is applied to the lens under full vision. 2. In the standard intracapsular extrac tion, the capsule is called upon to sustain a considerable weight. With cryosurgery, the traction is transmitted over the frozen cap sule and lens. Kelman and Cooper21 demon strated that when the capsule was held with forceps, it ruptured when a weight of 7.5 gm was applied, whereas it sustained weights up to 250 gm with the cryoextractor at - 2 0 ° C . 3. Cryoextraction is particularly desirable in subluxations. In the last two such cases which we handled with the Sudarsky instru ment, it was possible to avoid the trauma of pinning in both. COMPLICATIONS
Possible complications during cryoextrac tion include damage to the cornea, damage to the iris and vitreous adhesions. Our com bined experience in New Orleans, which is
CRYOEXTRACTION OF CATARACT
borne out by the published data, suggests that these complications can readily be avoided and that they are neither frequent nor serious. Complications in our 36 private cases were as follows : In one instance, the cryoextractor became adherent to the cornea and remained adher ent for five or six seconds. Separation was readily accomplished by irrigation with warm saline solution, and at the end of two weeks the cornea seemed entirely normal. In several other cases in which the instru ment became adherent to the iris, separation was difficult in only one instance. In that case we were somewhat slow in accomplish ing the separation and the iris finally had to be pulled away from the cryoextractor. The immediate result was an irregular pupillary tear, with an area of iris atrophy. The final result was merely a slight pupillary irregu larity. There was no interference with vi sion. In one case in which a subluxated lens lay beneath the iris in the lower nasal quadrant, the tip of the cryoextractor was necessarily placed over the edge of the lens and vitreous became adherent to the posterior surface of the lens as extraction was being accom plished. We had no difficulty in washing the vitreous away from the lens, and it retracted into its normal cavity without any loss. It was not until a similar situation developed in another case when the extractor was ap plied to the upper pole of the lens that we realized that we were freezing the vitreous as well as as the lens. As in the first case, separation was accomplished without loss of vitreous. Visual results in our private series met our expectations in every instance. In the Charity Hospital series, results were equally good except in one case, in which a poor re sult had been anticipated because of persis tent glaucoma caused by pre-existing trau matic angle recession. 812 Maison Blanche Building
(70112).
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REFERENCES
1. Conway, J. : Preliminary report of cataract extraction by freezing. Brit. J. Ophth., 49:141, 1965. 2. Sudarsky, R. D., Hulquist, R., and Chi, H. H. : Cryogenically induced iris atrophy, iridectomy and cataract in rabbits. Am. J. Ophth., 60:217, 1965. 3. Maumenee, A. E., and Kornblueth, W. : Regen eration of corneal stormal cells: II. Review of literature and histologie study. Am. J. Ophth., 32:1051, 1949. 4. Dunnington, J. H. : Some modern concepts of ocular wound healing. Arch. Ophth., 59:315, 1958. 5. Bietti, G. : Surgical intervention on the cili ary body; new trends for the relief of glaucoma. JAMA, 142:889, 1950. 6. Deutschmann, R. Cited by Sudarsky et al.a 7. Bietti, G. B. Cited by Sudarsky et al.2 8. Polack, F. M., and de Roetth, A., Jr. : Effect of freezing on the ciliary body (Cyclocryotherapy). Invest. Ophth., 3 :164, 1964. 9. McLean, J. M., and Lincoff, H. A. : Cryosurgery of the ciliary body. Tr. Am. Ophth. Soc, 62 :385, 1964. 10. Bellows, J. G. : Indications and technique of cryoextraction of cataracts. Arch. Ophth., 73:476, 1965. 11. Lincoff, H. A., McLean, J. M., and Nano, H. : Cryosurgical treatment of retinal detachment. Tr. Am. Acad. Ophth., 68:412, 1964. 12. Kelman, C. D. : Cryosurgery for cataract extraction and the treatment of other eye dis eases. Highlights Ophth., 7 :181, 1964. 13. Krwawicz, T. : Cryogenic treatment of herpes simplex keratitis. Brit. J. Ophth., 49:37, 1965. 14. Krwawicz, T. : Intracapsular extraction of intumescent cataract by application of low tem perature. Brit. J. Ophth., 45 :279, 1961. 15. : Further experience with intracapsu lar cataract extraction by application of low tem perature. Brit. J. Ophth., 47:36, 1963. 16. Davies, T. G. : Intracapsular cataract ex traction using low temperature. Brit. J. Ophth., 49:137,1965. 17. Chutko, M. B., and Zumbulidze, G. D. : Cryogenic method of cataract extraction. Vestnik Oftal., 77 :24, 1964. Abstract JAMA, 191:190 (adv. sect.), Feb. 22, 1965. 18. Rosengren, B. : Cataract extraction by means of the cryoextractor according to Krwa wicz. Tr. Ophth. Soc. U. Kingdom, 84:275, 1964. 19. Haik, G. M., Breffeilh, L. A., and Barber, A. : Beta irradiation as a possible therapeutic agent in glaucoma: An experimental study with the report of a clinical case. Am. J. Ophth., 31:945, 1948. 20. Cooper, I. S. : A cryogenic method for physiologic inhibition and production of lesions in the brain. J. Neurosurg., 19 :853, 1962. 21. Kelman, C. D., and Cooper, I. S. : Cryogen-
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ic ophthalmic surgery. Am. J. Ophth., 56:731, 1963. 22. Bellows, J. G. : Cryo-extraction of cata racts. Highlights Ophth., 7:114, 1964. 23. Sudarsky, R. D., and Hulquist, R. : Biophy sical aspects and instrumentation in ocular cryosurgery. In press. 24. Haik, G. M, Waugh, R. L., Jr., and Lyda, W. :
Sympathetic ophthalmia. Similarity to bilateral endophthalmitis phacoanaphylactica : New thera peutic methods. Arch. Ophth., 47:437, 1952. 25. Haik, G. M., Kalil, H. H., Ferry, J. F., and Childers, M. D. : Subluxations and luxations of the lens: With a special note on the Barraquer operation and on Marian's and Marchesani's syn dromes. South. M. J., 54:642, 1961.
T H E CLOSURE O F VERTICAL LID LACERATIONS* A N D T H E REPAIR OF VERTICAL LID CICATRICES E D M U N D B.
SPAETH,
M.D.
Philadelphia, Pennsylvania
cause of that a vertical laceration of the con junctiva is not complicated but a deep hori zontal one definitely is. One sees the same effect to a convincing degree in the ptosis of cervical-sympathetic paralysis. The levator tendon also has a significant effect upon a through-and-through lid lac eration. The levator tendon, if still function ing, widens a vertical laceration, in the upper lid, as the orbicularis fibers pull the two cut surfaces farther apart into an in verted V, the closer to the midline the lac eration the wider the gaping of the wound * From The Graduate Hospital of the Graduate (fig. 2). School of Medicine, University of Pennsylvania. The mechanics of defects from lacera This paper was presented before the Section of Ophthalmology, Philadelphia College of Physi tions of the lower lid are not too dissimilar. cians, March, 1965. The normal lid attachments to the fascial This paper is dedicated to a distinguished and beloved member of this Section, recently de sheath of the inferior rectus muscle and the ceased, Dr. Alfred Cowan, emeritus professor of connections of this to the lower lid and to ophthalmology, The Graduate School of Medicine the septum orbitale limit the gaping of a of the University of Pennsylvania. Some achieve greatness through the drive of great genius, laceration of the lower lid in the midline. others reach that through the fortune of an Eli- This anatomic anchor, however, combined jah-Elisha relationship,1 but Dr. Cowan attained with the downward pull of the facial mus the pinnacle because of his intellect, his impecca ble integrity and his consistently human aspect to cles of expression and the separating orbic all things professional and cultural. There is no ularis fibers, causes a gaping of a lower lid wonder that we who knew him loved him. Dr. laceration when the wound is in the outer Cowan was a clinician, as his books and many papers demonstrate, and he was happiest when in third or the inner third of the lower lid. vestigating disease and working with patients. It This is different from the tendency for is proper, therefore, that this paper, in memory of him, be clinical. The subject is chosen deliber upper lid midline lacerations to separate ately for he referred to me my first serious widely (figs. 3 and 4). ophthalmic plastic surgery problem in civilian life These are the conditions which modify for he knew that I had had these cases thrust upon me while I was in the military service. I the primary repair of injuries of the lids. am proud that I can pay Dr. Cowan homage this They apply also to the primary closure of evening. colobomas in the midline of the upper lid,
Before discussing the aspects of closure of vertical lid lacerations and repair of ver tical lid cicatrices, a brief review of the anatomy of the lids significant to the subject will help to explain why poor cosmetic re sults are not uncommon. The orbicularis muscle fibers form a sphincter, adherent through the canthal liga ments (fig. 1) to the lateral and medial edges of the orbit. The Müller muscle fibers in the superior cul-de-sac are adherent to the conjunctiva of the superior fornix. Be-