Chapter III: Part 3

Let us consider the first of the three procedures just mentioned--_iridectomy_--introduced by von Graefe. The mechanism of its mode of cure is best studied in cases of acute primary glaucoma, when there is apposition of the periphery of the iris to the cornea. In these acute cases there is probably only a mere _apposition_, and the blocking up of the sclero-iridian angle is largely mechanical. Here the root of the iris is readily removed in its entirety and a really peripheral iridectomy is easily done. When, however, a true _adhesion_ between corneal and iridic tissue takes place the filtration angle is not so easily opened. True peripheral adhesions are not readily broken up or separated, and the iridectomy is, for that reason at least, not effective. Moreover, this form of anterior synechia (resulting from a true union of iris and cornea) is so intimate that the iris root is, by the iridectomy, torn away only at the sclero-iridian angle at the anterior border of the adhesion--and does not open up a channel into Schlemm's canal. It is not, therefore, difficult to understand why iridectomy alone in any of the forms of chronic glaucoma fails to open up the true filtration spaces and does not provide a drain that permits of an escape of fluid from the posterior chamber through the loose tissue that surrounds it into the canal of Schlemm. Treacher Collins found, after a careful examination of eyes upon which iridectomy had been performed for glaucoma, that it is extremely rare for the initial section to pass through the pectinate ligament, while Schlemm's canal invariably escapes. Moreover, since the sclero-corneal incision is uniformly oblique, the position and extent of the external wound does not always furnish evidence of the character of the internal wound. In all likelihood many cases of relief or cure following iridectomy are those due to the formation of cystoid scars or minute fistulae, rather than as a result of the removal of a portion of the iris periphery.

The best brief tabulation of the results obtained by iridectomy, in glaucoma, is to be found in Weeks' textbook on _Diseases of the Eye_, page 417: "Sulzer reports as follows: Acute glaucoma, 149 cases; improved, 72.5 per cent; serviceable vision preserved, 11.3 per cent; vision impaired at once, 4.08 per cent; very little vision, 12.12 per cent.

"Zentmeyer and Posey: In simple glaucoma central vision increased in 60 per cent; remained the same in 20 per cent; diminished in 20 per cent.

"Wygodski: Inflammatory glaucoma, 37 cases; improvement, 76 per cent; unimproved, 5 per cent; deterioration, 19 per cent. Sub-acute (chronic inflammatory), 147 cases; improvement 10 per cent; unimproved (condition the same as before iridectomy), 40 per cent; deterioration, 30 per cent; blindness, 20 per cent. Cases operated on at an early stage gave 85 per cent of good results. Simple glaucoma, 104 cases; improvement, O.96 per cent; condition as before, 10.5 per cent; deterioration, 52 per cent; amaurosis, 36.5 per cent.

"Hahnloser and Sidler: One hundred seventy-two eyes observed not less than ten years after operation; acute inflammatory, 31 eyes; good results, 64 per cent; relatively good, 13 per cent; blind 23 per cent; chronic inflammatory, 37 eyes; good result, 29.9 per cent; relatively good, 27 per cent; blind, 43 per cent; simple glaucoma, 76 eyes; good results, 42 per cent; relatively good, 28.9 per cent; blind, 28.9 per cent."

As far as the _Lagrange procedure_ is concerned, you will remember that after eserinization an oblique incision is made through the sclera by means of a narrow Graefe knife and a large conjunctival flap secured. This is obtained by making a peripheral section of the sclero-corneal margin with the knife and, as soon as the edge of the knife reaches the upper limit of the anterior chamber, it is turned backward and brought out through the sclera obliquely. The conjunctival flap thus formed is turned back over the cornea, and the fragment of sclera that is left attached to the cornea is removed by means of a fine pair of delicate curved scissors. Following this an iridectomy is performed. The conjunctival flap is now replaced and a bandage applied.

This operation opens a large filtration passage for the intra-ocular fluids and the prompt healing of the wound with its mucous covering prevents prolapse of the iris.

Under no circumstances must iris be left between the lips of the wound.

Although Lagrange advocated iridectomy in all cases in his first communication, he no longer judges the procedure to be necessary in all instances, reserving it for cases in which for any reason, such as hypertension, prolapse is to be feared.

While Lagrange holds that it is necessary to open the anterior chamber, Bettremieux thinks that a removal of but a portion of the thickness of the sclera suffices. His procedure is as follows: After raising a flap of conjunctiva from the neighborhood of the limbus a medium sized needle, curved and flattened towards its point and firmly grasped in a needle holder, is thrust superficially into the sclera tangentially to the upper edge of the cornea, so as to become fixed in the capsule of the eyeball. A small shaving of the sclera, about 1/2 mm. thick, 11/2 to 2 mm. broad and from 2 to 3 mm. long, is then excised by means of a narrow Graefe knife. The scleral slip is then freed from the conjunctiva at each end and the mucous membrane brought together over the wound by fine catgut sutures.

As you are well aware, numerous operators regard the Lagrange operation as superior to the iridectomy of von Graefe because they believe there is filtration through the newly formed tissue between the lips of the operative wound. Among those of many observers the conclusions of Ballantyne may be quoted: "The results of sclerectomy vary according to the degree of hypertension of the eye operated on. Three varieties of cicatrix are distinguishable according to the amount of sclera excised: (1) that in which there is mere thinning of the sclera owing to the excised portion not reaching the posterior surface of the cornea (conjunctiva smoothly covers the cicatrix); (2) that represented by a subconjunctival fistulette, due to excision of the whole thickness of the sclera, in an eye with moderate tension (the conjunctiva lies smoothly over the cicatrix); (3) the fistulous cicatrix with an ampulliform elevation of the overlying conjunctiva, resulting from excision of the whole thickness of the sclera in an eye the seat of high tension. In cases of high tension, even a simple sclerectomy will allow ample filtration, owing to the gaping of the wound, while in cases without elevation of the tension, sclerectomy will be quite ineffectual. Lagrange therefore proposes the following rules of procedure: (a) If tensions is normal to +1, do sclerectomy without iridectomy, the amount of sclera excised being inversely proportionate to the degree of hypertension. (b) If tension is +1 to +3, do sclerotomy-iridectomy, the iridectomy being added to avoid entanglement of the iris. Lagrange does not recommend his operation for acute glaucoma. It is especially adapted for cases of chronic simple glaucoma."

During the past ten years or more I have been doing a modification of the Lagrange operation, the details of which (The Operative Treatment of Glaucoma with Special Reference to the Lagrange Method, _The Canadian Medical Association Journal_, November, 1911) I have elsewhere published.

As stated in this paper I have modified the procedure to the extent of removing _all_ the conjunctiva attached to the borders of the operative wound. I admit that this intervention exposes the root of the iris and the ciliary body, but I have never yet had the slightest infection of the wound. I attribute this freedom from sepsis to careful cleansing of the conjunctival sac and to other pre-operative precautions, but especially to the use, before and after the operation, of White's ointment--a preparation of 1-3000 mercuric chloride in sterile vaseline. One cannot use sublimate in such a strong _watery_ solution, but the vaseline seems to modify it and to allow of such slow absorption that it is not only a non-irritant but a most excellent antiseptic application in operations on the eye.

In any event the result of the Lagrange operation proper, as well as my modification of it, is to produce a drainage-oedema about the incisional wound which persists almost indefinitely. In many cases this swelling amounts to a bleb which may be increased by massage of or pressure upon the eyeball. The efficacy of the operation in lowering intra-ocular tension is to some extent measured by the degree and the constancy of this epibulbar oedema; indeed, I suspect that the most successful examples are those in which sclera fistulae, minute or otherwise, form as a sequel of the operation.

My object in excising the conjunctiva about the sclero-corneal flap, is to delay union of the wound edges, to widen the bridge of loose cicatricial tissue between them, to prevent such a complete growth of the endothelium as would cover the wound and block the exit of fluids, and to insure intra-ocular rest.

In cases of _chronic_ increase of intra-ocular tension associated with a quiet uveitis or an iridokeratitis, when the patient exhibits traces of old synechiae, or where there is danger of their re-formation, I do not hesitate to use atropia as long as the wound of operation has not healed.

To the present time I have done 72 operations of the sort and have seen no reason to alter the opinion of it expressed in the article mentioned. Whatever objection may in the future arise--and I freely confess that it _seems_ to be fraught with the dangers that many of my colleagues have pointed out as probable--I have so far not seen a single case of infection of the wound of operation. While I believe the anti-glaucomatous results to be excellent, I may also claim that the operation is of the simplest character; and it is easy of performance and the resulting filtration-scar is large and (perhaps) more permeable to the changed intra-ocular fluids than the quicker healing wounds of the usual Lagrange and Elliot procedures.

It is regarded by most operators as desirable that there should not be long delayed healing of the operative wound, and the fact that the conjunctiva covers the incision is often spoken of as an advantage, partly because it shields the large open area produced by the Lagrange incision from infection.

My experience of this modified operation continues to be that it is necessary to clear the neighborhood of the operation wound entirely of conjunctiva. If the down-growth of epithelium into the operative wound is permitted the effects are by no means as pronounced, and the eventual lowering of tension is not as permanent as they otherwise would be.

Another matter: I am satisfied that the delayed filling of the wound by connective tissue is desirable in most cases of _chronic_ glaucoma. A complete drainage of the intra-ocular fluids that results from long delayed union of the wound edges, allows the interior of the eye to regain, as far as possible, the _status quo ante_. On the other hand the comparatively early closure of the wound (or the termination of _free_ drainage and minus tension) tends to re-establish the _status glaucamatosus_. Whether these desirable results are to be realized or not will, of course, depend upon a future experience larger than I have yet had. This modification of the Lagrange operation seems to be a radical one and I do not expect its adoption until the results of an extended trial are carefully recorded and reported.

Quite recently several operators, who have been in a position to do so, have contrasted the results obtained by the Elliot method and those following the Lagrange procedure. Probably the most important of these observations is the experience of Meller (Die Sklerektomie nach Lagrange und die Trepanation nach Elliot) set forth in a paper read by him at the last meeting of the _Deutsche Naturforscher und Aertze_. In this report Meller gives an account of 389 sclerectomies following the usual Lagrange procedure. Twelve per cent of the cases were of acute glaucoma; 61.5 per cent of chronic inflammatory glaucoma, and 9 per cent of simple glaucoma. The rest of the operations were done in other forms of the disease. In more than half the cases the usual iridectomy was performed; in 30 per cent the procedure was peripheral; in 4 per cent there was no iridectomy. The patients were studied during a period of five years. In more than half the instances there was a pale, cystic, oedematous cicatrix; in 11 per cent the scar was ectatic, and in the remainder the field of operation was quite flat. The form of the scar was described in most instances, but it was not noticed that there was a definite relation between the cicatrical formation and the intra-ocular tension. In 70 per cent of the cases a good result followed the operation, but in 10 per cent the result was decidedly unsatisfactory. Cloudiness of the lens set in in 4 per cent of the cases, while posterior synechiae developed in the great majority of them. In 2.3 per cent the eye was attacked by iridocyclitis and in 3.4 per cent enucleation was found to be necessary. Six eyes became atrophic but were not, for various reasons, removed. One and three-tenths per cent of the eyes operated on were lost from late infection. Vitreous was lost in 6.2 per cent. Two eyes became blind from expulsive hemorrhage. The large majority of these complications arose in the eyes operated on for chronic glaucoma. There were fewer eyes lost following the operation for glaucoma simplex than in the other forms of the disease. Recurrences were noticed in 11.3 per cent of all the cases; in simple glaucoma 14.3 per cent as against the acute and chronic forms with 6 per cent. A return of the glaucoma was noticed in 7 per cent of the pale, oedematous, post-operative scars, in 16 per cent of the flat cicatrices, and in 24 per cent of the ectatic variety. Considerable stress is laid upon the fact of the marked softness of the eyes after each operation. There were histological examinations made of the eyeballs in 11 cases, in which the position of the incision and excision, the development of the scar tissue, and the appearance of the complications were duly set forth. The operator then gave a history of over 178 trepanations after the Elliot method and compares them with the procedure of Lagrange. He concludes that the Elliot trephining operation is less dangerous, is more likely to be followed by the development of a cystic scar, and leads to loss of the eye in only 2.4 per cent of the eyes operated on. In Elliot's cases the percentage of relapse was more noticeable than in the Lagrange cases where no iridectomy was done. This observer concludes that the method of Elliot is to be preferred to that of Lagrange, and that in the former case iridectomy is an important factor in obtaining a favorable result. This being the case one cannot truthfully say that trephining alone can take the place of the old Graefe iridectomy. On the other hand, trephining may with advantage be employed instead of iridectomy for cases difficult or dangerous under the latter method.

Whatever difference of opinion was noticeable at the Vienna meeting, all of those present, especially Meller, the reader of the paper just quoted, were decidedly of the opinion that the Elliot operation is in every respect the one best adapted to buphthalmia, or congenital glaucoma.

In conclusion let me say that the acceptance or rejection of Colonel Elliot's procedure or any other operation is not to be decided by the percentage of iritis, secondary cataract, relapses, lost eyes, etc., but by deciding whether or not his procedure in the various forms of glaucoma gives the best results, including the preservation of comfortable eyes. In other words, we are seeking not the operation that will cure _every_ case of glaucoma but the one which is capable, _in the hands of the average ophthalmic surgeon_, of relieving or curing _most_ cases of that affection.

Dr. Casey A. Wood's Paper on Operations Other than Scleral Trephining for the Relief of Glaucoma

Discussion,

ALBERT E. BULSON, JR., M.D.,

Fort Wayne.

Increasing belief in Colonel Elliot's view that trephining should be the operation of choice in any form of glaucoma, makes it difficult to consider operations other than trephining in anything but a spirit of disfavor.

Until recently the decision as to the kind of operative procedure to be employed for the relief of glaucoma has depended on the form and stage of the disease, and the amount and character of the vision of the affected eye. Many operators still hold that an iridectomy is the most valuable of all operations for acute inflammatory glaucoma, and not a few hold that the operation has a decided place in the treatment of simple glaucoma. The operation is not without difficulties, and one is inclined to agree with Elliot who says that "The man who can make a 'finished iridectomy' quietly and cleanly has graduated as an ophthalmic operator." The difficulties of an iridectomy are especially pronounced in those cases in which the anterior chamber is extremely shallow and the iris is pressed against the cornea. It is in such cases that the success of the operation is increased by the addition of posterior sclerotomy and the intelligent use of miotics prior to the performance of the iridectomy. Even then the permanent results of the iridectomy will be modified in proportion to the success secured in freeing the filtration angle and opening Schlemm's canal by thorough removal of the root of the iris.

The failure of many apparently well executed iridectomies may be attributed to the fact that the iris is not removed to the extreme root, and the remaining stump is sufficient to block the drainage. This is especially apt to be the case in chronic glaucoma where the iris is adherent to the cornea, and in efforts to free the filtration angle by an iridectomy the iris is torn off in front of the adhesion and the filtration angle is not opened.

As Elliot has pointed out, iridectomy is most open to attack on the ground of safety. We have to take into account the large scleral wound made, and the fact that this lies close to the ciliary body. The sudden release of all tension and the simultaneous weakening of the supports of the lens and vitreous body create very unfavorable conditions under which to make the crucial step of the operation.

The poor results following an iridectomy in chronic glaucoma have led to the devising of many substitute operations, of which those tending to the production of a filtering scar are now preferred, and, experience shows, hold out the most hope of bringing about long continued relief. It even is considered probable that the effects of an iridectomy which brings about more or less permanent reduction in the intra-ocular pressure is due to the formation of a filtering scar which augments whatever results may have been secured in the attempt to open up the drainage into the canal of Schlemm.

Dr. Wood has referred to several of the many substitutes for iridectomy that have been proposed, and it is unnecessary to enumerate them again or to attempt to point out their good or bad features. It is sufficient to say that for the average operator and the larger per cent of cases, the operation which is easiest to perform, is attended with the least risk and offers the best hope of permanent results should be the one of choice. Sympathectomy has failed to secure a place in ophthalmic surgery, sclerotomy has not been found adequate, and cyclodialysis is not sufficiently simple of execution or permanently beneficial in its results to give it prominence.

Of the operations proposed for the formation of a filtering cicatrix, those of Elliot and Lagrange are justifiably the most popular. Those of us who have had the pleasure of seeing the trephining operation done by Col. Elliot are impressed with the fact that the operation, even in the hands of its originator, is not, when properly done, uniformly easy of performance. It does, however, offer the advantage of carrying with it the minimum amount of risk, and the apparently permanent results secured justify the ophthalmologist in acquainting himself with the technique of the operation, for, as pointed out by Sydney Stephenson and others, "the technique is responsible for success or failure." Furthermore, there is no sufficient reason why the field of usefulness of the operation should be confined to the chronic forms of glaucoma, and Col. Elliot unhesitatingly recommends trephining as safer and more efficient than any other operative procedures at present employed for the relief of acute glaucoma.

The success of the Lagrange operation, which, like the Elliot operation, aims to produce a fistulous communication between the anterior chamber and the sub-conjunctival area, depends upon securing the removal of a relatively large section of all of the layers of the scleral and corneal lip of the wound, so that a permanent opening, covered by the replaced conjunctival flap, is made. Unlike the trephine operation which was evolved from it, the Lagrange operation requires the same kind of an opening of the eyeball as required for a well executed iridectomy, and a properly placed section entirely in scleral tissue, with a good sized conjunctival flap, are elements which enter into the ultimate success or failure of the procedure.

Aside from the dangers incident to a wide incision in the neighborhood of the ciliary body and the possibility of accident to the lens or vitreous body, or of intra-ocular hemorrhage, there is for the average operator the added difficulty and danger in removing a piece of sclera of the exact size required. The technique of the operation is even more difficult and exacting than in the performance of the trephine operation, and it also compares unfavorably in safety.

The advisability of removing the conjunctival flap, as advocated by Dr. Wood, as a modification of the Lagrange operation, may be seriously questioned, for aside from the fact that apparently no advantages in aiding permanent filtration are added, there is, added to the objections to the Lagrange operation already mentioned, the very serious disadvantage of subjecting the area at the root of the iris to infection for a prolonged period of time. The advantages of the protection afforded by a conjunctival flap far outweigh the disadvantages of a remotely possible interference of drainage by the blocking of the open wound with conjunctival tissue. The fortunate experience of Dr. Wood in not having infection in a wound which remains open and unprotected for variable lengths of time is not likely to be the experience of any considerable number of operators, and probably will not always be the experience of Dr. Wood. Furthermore, the possibilities of damage by hemorrhage from the choroidal or retinal vessels, delayed formation of the anterior chamber and adhesion of the capsule of the lens to the wound, and the injurious effects of even slight trauma subsequent to the operation, including loss of vitreous, are increased by omitting the conjunctival flap.

The modern operation for the relief of glaucoma, by which a filtering scar is produced which permits escape of liquid from the anterior chamber, is the one which apparently holds out the most hope of permanently relieving the condition. While success will depend always to a certain extent upon the personal equation, yet it seems now that for a large majority if not all of the cases we are justified in abandoning all other operations than trephining, notwithstanding the verdict of Elschnig and others that fistula forming operations eventually will be discarded in favor of iridectomy and cyclodialysis.

Late or secondary infection, not unknown following iridectomy, may follow the trephine operation, and already some fifteen or sixteen cases have been reported. But while this possibility is a real danger, which improved technique may greatly minimize (Col. Elliot has not seen a case of secondary infection in an experience of over 1200 trephining cases of his own and a large number of others performed by his assistants and pupils) the ultimate verdict must rest with results as compared with other measures. At present, as pointed out by Meller, whose statistics Dr. Wood has cited, trephining heads the list of remedial measures for the relief of glaucoma, and it has the advantage of being applicable to any form of the disease, to be relatively free from danger, either immediate or remote, and to produce the highest percentage of favorable results. The addition of an iridectomy in every case of trephining does not unduly complicate the operation and has much to commend it in offering the patient every possibility of relief.

INDEX

PAGE
ETIOLOGY AND CLASSIFICATION OF GLAUCOMA,
_Edward Jackson, M.D._ 9

ETIOLOGY AND CLASSIFICATION OF GLAUCOMA,
Discussion, _Francis Lane, M.D._ 28

PATHOLOGY OF GLAUCOMA,
_John Elmer Weeks, M.D._ 37

PATHOLOGY OF GLAUCOMA,
Discussion, _E. V. L. Brown, M.D._ 57

CONCERNING NON-SURGICAL MEASURES FOR THE REDUCTION OF INCREASED INTRA-OCULAR TENSION, _George Edmund de Schweinitz, M.D._ 61

CONCERNING NON-SURGICAL MEASURES FOR THE REDUCTION OF INCREASED INTRA-OCULAR TENSION, Discussion, _Nelson Miles Black, M.D._ 101

TREPHINING FOR GLAUCOMA,
_Robert Henry Elliot, M.D._ 107

TREPHINING FOR GLAUCOMA,
Discussion, _Frank C. Todd, M.D._ 113

OPERATIONS OTHER THAN SCLERAL TREPHINING FOR THE RELIEF OF GLAUCOMA, _Casey A. Wood, M.D._ 121

OPERATIONS OTHER THAN SCLERAL TREPHINING FOR THE RELIEF OF GLAUCOMA, Discussion, _Albert E. Bulson, Jr., M.D._ 141