Operations Upon The Conjunctiva, Cornea, And Sclera; Enucleation And Evisceration

Operations Upon The Eye
By S. C. AYRES, M. D.,
OF CINCINNATI.

OPERATIONS upon the ocular muscles may be necessary for the relief of concomitant and paralytic strabismus, as well as for want of balance in opposing muscles where squint does not exist.

The surgical correction of strabismus includes tenotomy of one or more of the ocular muscles, or advancement combined with tenotomy. Partial and complete tenotomies are also performed to correct various types of heterophoria, and advancement may be employed for the same purpose. Finally, advancement preceded by tenotomy of the opposing muscle is utilized to relieve the faulty results of strabismus operations, or in certain cases to counteract the deviation produced by paralytic squint.

1. Complete Tenotomy. (a) Tenotomy of the Internus. The operation for convergent strabismus which has been very generally adopted is the one devised by v. Graefe. It is the easiest of all the operations, and has only one disadvantage, if it may properly be so called namely, the necessity of a suture in the conjunctiva. It is performed in the following way:

After the conjunctiva is cocainized the lids are separated by a spring speculum, and an assistant seizes the conjunctiva close to the outer side of the cornea and rotates the eye directly outward in the axis of the commissure, in order to prevent the natural tendency of the patient to turn the eye upward. The operator grasps the conjunctiva with a pair of forceps directly over the tendinous insertion of the muscle, raises it, and makes an opening, either in a vertical or horizontal direction, large enough to admit the easy introduction of the hook. Next, the subconjunctival tissue is incised, so as to expose the tendon of the muscle, and the hook is passed beneath the tendon, care being exercised to secure the entire tendon. The muscle is severed close to its insertion in the sclera with two or three cuts of the scissors.

An examination should now be made with the hook, above and below, to determine whether the tendon has been entirely severed, and also to ascertain whether any offshoots remain which may limit the motion of the eye outward. If the patient is not anesthetized, this may be readily determined by directing him to forcibly rotate the eye outward. The patient should next be directed to “fix “an object near by the point of a pencil or the tip of the finger. If convergence still remains, the effect of the operation may be increased by incising the capsule of Tenon. This should be done with care, and, after snipping the capsule above and below the severed tendon, adduction and abduction should be tested. If the effect is satisfactory, the conjunctival wound should be closed with one or two sutures, both eyes bandaged, and the patient required remaining within doors until the following day, when the bandage may be removed.

If too much effect has been pro duced, a suture should at once be inserted in the cut end of the muscle from within outward and brought out through the conjunctiva close to the cornea. It should be securely tied, and then a bandage applied, as above di¬rected, until the following day, when the eye should be opened and allowed to take part in the visual act. The primary suture may be removed on the second day after the operation, but when a suture is introduced to counteract excessive effect it should remain for two or three days.

(b) The subconjunctival operation, commonly known as Critchett's operation, is done in the following way:

The eye having been cocainized, the lids are separated by a spring speculum (it is supposed the internal rectus is to be operated upon), and an assistant firmly seizes with forceps the conjunctiva and subconjunctival tissue near the outer edge of the cornea to prevent rotation of the eye on its axis. The operator next raises the conjunctiva with a fine toothed forceps over the lower border of the rectus muscle, and makes an opening sufficiently large to admit easy insertion of the scissors and hook. It is better to have this opening too large than too small. After the incision of the con junctiva the. subconjunctival tissue is divided by successive short snips with the scissors, and undermined in the direction of the caruncle, until an opening is made in the capsule sufficiently large to enable the operator easily to introduce the book. The hook, held in the right hand, is inserted on the flat, its point in contact with the sclera, and is passed under the muscle and drawn toward the insertion of its tendon. Then the point is elevated until it raises the conjunctiva in a tent like manner. The hook is now grasped by the left hand of the operator, the assistant removes the forceps, and the tendon is severed by a series of short snips until the lessening of resistance and the elevation of the hook under the conjunctiva indicate complete division of the tendon. Where the tendinous insertion is broad it may not be entirely taken up on the hook, and another attempt to secure it should be made. After the section has been performed the hook should be swept through the opening in order to catch any strands which may have escaped division. If a decided effect is desired, the opening in the capsule, above and below, may be enlarged.

The conjunctival wound does not need a suture to close it, and only a compress bandage for a day is necessary. It is more difficult to perform this operation than the one previously described, because the tendon cannot be seen, but only felt. Sometimes with an unruly patient the cutting is not smooth; occasionally the tendon slips off the hook. Straight scissors are better in this operation than curved, although the operator may use the kind he prefers.

(a) Snellen's Method. Snellen makes a vertical incision in the conjunctiva directly over the middle of the tendon of the muscle. After the opening has been sufficiently enlarged and the tendon exposed he seizes it with a pair of forceps and makes an opening or buttonhole in it, through which be passes the hook and cuts the upper portion, and then the lower portion, of the tendon in succession, close to the sclerotic. The subsequent dressings are the same as after the Greets operation. He claims that this method does not interfere with the capsule of Tenon or with the indirect insertion of the muscle in its connection with the capsule.

In order to increase the effect of a tenotomy, in certain cases Knapp inserts a suture through the superficial layers of the sclera at the outer side of the eye and passes it through the skin beyond the outer canthus, where it is tied and allowed to remain a few hours. If insufficient effect is found to exist the day after the operation, it can be remedied in some cases by again cocainizing the eye and opening the wound, and passing the hook under the tendon and separating it from the sclera.

There is a marked difference in the size and strength of internal recti muscles. The hook can be readily pushed beneath most of them, but occasionally a tendon is found which is thick and broad, and apparently drawn very tightly over the sclerotic, and which presents an unusual amount of resistance. In such cases only the point of a hook can be inserted underneath the tendon, which must be severed by successive short snips. In these cases there is danger of perforating the sclerotic.

Choice of Operation. It is probable that most of the tenotornies of the internal rectus are performed either by Graefe's or Critchett's method. The judgment and experience of the operator will be his guide in choosing the one best suited to each individual case. The writer prefers the subconjunctival operation.

(d) Tenotomy of an Externus. This is accomplished in a manner identical with that described in connection with the internus. The external rectus is inserted farther from the cornea (7 to 8 mm.) than the internus, its insertion is not so broad, and it is more lax than the inner muscle. The effects of its division are not so marked as those seen after tenotomy of the internus, and hence are often disappointing. Not infrequently it is necessary to tenotomize both externi simultaneously.

(e) Gruening's Method. In absolute divergent strabismus Dr. Gruening tenotomizes both external recti at one sitting, as follows :

Where the divergence is not more than 2 mm. the tendons are divided at their insertion. Whenever the deviation measures more than 2 mm. the tendons are divided at a distance from their insertion, this distance corresponding to the degree of squint. When the deviation amounts to 5 mm. by the corneal reflex, both tendons are divided at that distance from the points of insertion. After closing the conjunctival wound a silk suture is passed through the conjunctiva over both interni muscles in a line with the horizontal meridian of the corneal and tied over a pledget of cotton on the bridge of the nose. This position is maintained twenty four hours.

(f ) Tenotomy of the Superior and the Inferior Rectus. In operating on the superior and the inferior rectus muscles the same precautions are required as in operations on the internal and external muscles. It is better to employ the open method by cutting down upon and exposing the insertion of the tendon.

II. Graduated or Partial Tenotomy. Operations on the internal, external, and vertical muscles for esophoria, exophoria, and byperpboria are made by partial or graduated tenotomies, as devised by Dr. Geo. T. Stevens. The tendon of the muscle is partially severed, and then a test of the effect produced is made and the operation continued until the desired result is obtained. Dr. Stevens operates as follows:

If the right internus is to be operated upon, the patient is directed to turn his eyes well to the right. The surgeon, with a pair of fine forceps (Fig. 406, A, B), takes a minute fold of the conjunctiva at the center of insertion of the tendon. Drawing this little fold of conjunctiva slightly away from the eyeball with the extreme point of the tenotomy scissors (Fig. 406, 0), the operator snips the fold transversely, so that an opening 1 mm. in extent is made through the membrane. Now the forceps, the points being closed, are pressed into the little opening and slightly backward, where the points are permitted to spring apart, after which they are again closed, this time holding a small fold of the tendon just behind the insertion. This being put upon the stretch, the scissors by little snips dissect the tendon from the eyeball between the layers of the capsule (which should remain intact) toward one border of the insertion. Then the tendon is cut toward the other border of its insertion. After this the tests for adduction and abduction are made, and further operative interference regulated according to the results. In like manner, the tendon of the external, superior, or inferior rectus may be partially divided.

This operation has received commendation and criticism, and it is open to both. It is suitable to cases where a very slight effect is desired. The fact that it has to be repeated several times is an argument against it, and in favor of a more pronounced effect which can be gained in one or two partial tenotomies.

Ill. Advancement or Readjustment and Resection. In this operation the tendon of a rectus muscle is brought forward to a new attachment.

(a) Advancement to Correct Faulty Strabismus Operations. Operations for advancement after squint operations present difficulties and complications not found in other cases. The conjunctiva over the incision is generally firmly cicatrized to the subconjunctival tissue and sclera. This may be due to the fact that the original incision was not closed by a suture and that the exposed scleral surface bad granulated. Again, the insertion of the muscle is sometimes very thin and cord like, and is attached to the sclera by a mere thread. The retraction of the muscle may have been very great, and one must search, carefully for its new and abnormal insertion.

First, the cicatricial surface should be denuded by cutting away this tissue until the sclera is exposed and the muscle brought into view. A hook is Dow passed beneath the muscle, which is raised up until it can be seized with catch forceps, when its insertion is severed. If the muscle is atrophied and cord like, it will be necessary to insert the needles very far back in order to secure the necessary purchase, and the difficulties of passing the needles under these conditions are sometimes very considerable, owing to the cicatrization above mentioned. If the muscle is thin, a thread armed with three needles, as described elsewhere (de Wecker's advancement operation, see below), should be used; but where it is broad enough for the insertion of one thread through its upper and another through its lower border, this is the better plan to adopt, because it spreads the muscle and gives it a more secure attachment to the sclera. Both eyes should be bandaged for two or three days after the operation. As soon as the eye is firmly fixed in its new position, providing no inflammation has ensued, both eyes should be opened and the patient allowed to walk as usual around the ward or house.

(b) De Wecker's Method of Advancement. De Wecker's operation is performed in the following manner:

A vertical incision is made in the conjunctiva close to the cornea, and the Subconjunctival tissue cut away until the tendon of the muscle is exposed. One branch of a de Wecker's clamp is now passed under the tendon of the muscle, and when it is in the proper position the other branch is pressed down, thus holding it by the forceps (Fig. 407). The tendon is Dow severed close to the sclera, and an exploration is made with a small book to ascertain whether any fibers or offshoots of the muscle remain. A thread armed with three needles, one in the middle and the other two not far from the ends of the suture, is prepared for the second step of the operation. The middle needle is passed through the center of the tendon from its under surface, and comes out through the conjunctiva. The location of this stitch is regulated by the effect to be produced, being inserted nearer the caruncle when more effect is desired. The two needles are then passed deeply under the conjunctiva, coming out in the vertical meridian of the eye at a distance of 4 mm. from the cornea, one above and the other below. The clamp forceps are now removed, and, if the muscle is to be shortened, that portion of the muscle within the clamp is severed. The middle needle having been cut off and the others also removed, the two sutures are tied as follows: The operator and his assistant each take one of the threads and simultaneously tighten them. When the desired position has been attained the knots are tied and the ends of the thread cut off. An overcorrection is made, because after removal of the threads the tendon recedes from the original position.

If after two or three days there is an over correction, the threads are removed, and, after cocainizing the eye, a delicate hook is introduced into the wound and the attache ments of the muscle loosened sufficiently to overcome the defect. If this is not necessary, the stitches are allowed to remain until the fifth or sixth day.

(c) Noyes's Operation for Advancement. Dr. Noyes describes his operation as follows:

“Suppose the right rectus internus is to be advanced. The right rectus externus is first divided; then seize the insertion of the rectus internus with fixation forceps, taking a deep bite to include all that can be lifted; sever the insertion freely, and cut down above and below into the conjunctiva to the extent of 10 to 15 mm.; have the forceps fast to the tissues by shutting the spring catch, lay it aside and then remove a vertical oval of conjunctiva in front of the insertion, leaving a strip 6 mm. wide next the cornea. Lift the muscle and pass a curved needle from within outward at its middle and as far back as the proposed effect will demand. With the needle in place cut off superfluous material in front of it, and then draw it through. The other two needles are introduced in succession and the tissues in front are cut off. This is done to avoid the danger of cutting off the sutures. We now have three threads through the muscle fascia and conjunctiva. The needles at the other ends of the thread are next to be passed forward beneath the remaining conjunctival strip, taking hold of the outer layer of the sclera, so that the points emerge at the limbus cornea. The middle thread is tightened first, and then the others in succession. The double knot is not tied until the threads have been successively tightened, and the eye is in a proper position. If there is much crumpling of tissue, it must be cut away, leaving the parts smooth. The stitches are allowed to remain from four to seven days. A bandage is applied for twenty four or forty eight hours."

The author does not think it necessary, except in rare cases, to cut away the conjunctiva as recommended above. He has found that it usually smooths down in a short time.

(d) Schweigger's Operation of Resection of a Rectus Muscle.Schweigger incises the conjunctiva vertically, as well as the' tissue of Tenon's capsule over the insertion of the muscle to be advanced. A hook, curved on the flat and with an olive point, is passed underneath the muscle and lifts it, exposing to view the entire tendon. A second hook is passed under the muscle in the opposite direction. One hook is pressed toward the corneal margin as far as the insertion of the tendon will permit, and the other one to that point where it is desired to insert the threads, thus exposing the muscle from 3 to 10 mm.

Two double armed catgut threads are now prepared. One needle is passed under the upper edge of the muscle and pierces the same below the middle. The second is passed from the lower end and pierces the muscle above its middle. Each thread is then tied, thus including the entire muscle. The amount to be tied off is measured with a millimeter rule. That portion of the muscle between the catgut threads and its insertion is then resected. Then the two needles are passed through the insertion or stump of the muscle and superficially through the sclera. Both the threads are now tied and cut off and the conjunctival wound closed with silk sutures. The antagonistic muscle is always tenotornized before the sutures in the muscle to be advanced are tightened.

(e) Prince's Single suture Advancement. Dr. A. E. Prince has devised what he calls the 11 pulley operation." An anchor or pulley loop is made in the dense episcleral tissue about 1 mm. from the corneal margin. The sutures inserted into the muscle are passed through this loop, and, being fixed and solid, it afrords an unyielding point of resistance. This method was later modified by its author to a single suture operation, which is performed in the following manner:

A conjunctival incision is made over and parallel to the attachment of the tendon of the muscle to be advanced. The tendon is secured by an advancement forceps (Fig. 408), separated from the sclera, and advanced, allowing the conjunctiva to retract. Two slender eye needles (Tiemann No. 25) on either end of a No. 3 iron dyed silk suture are passed from within outward, perforating the capsule, muscle, and conjunctiva at a variable point depending upon the amount of displacement to be effected, thus securing the middle portion of the muscle in a sling from which it can neither slip nor escape. With the exception of cases requiring a small amount of advancement of the muscle, as those in which the suture is used as a control to prevent an over correction following a tenotomy, the portion of the tendon in the grasp of the forceps is exsected about 2 mm. anterior to the sling. The sclera being now fixed, preferably with Critchett's short fixation forceps, an unyielding anchorage in the form of a fibrous pulley is secured in line with the rectus by introducing either needle into the dense episcleral tissue 2 mm. from the sclero corneal junction (Fig. 409).

Both ends of the suture are now brought together, forming the first portion of a surgical knot, and tightened to effect a slight over correction. This suture is permitted to remain four days, unless it is desired to diminish the effect, which may be safety done after forty eight hours by removing the suture and opening the wound with a small strabismus hook. Tenotomy of the opposing muscle is made as in other operations.

This operation is better than the one first described by Dr. Prince, and gives very satisfactory results.

Dr. E. E. Holt has devised a somewhat similar operation!

(f ) Landolt's Operation for Advancernent. Landolt is a firm believer in the incomparable superiority of the advancement of the muscle over its setting back." He says : " There is more than one good method which leads to the same end. The essential point in all advancements consists in always bringing the muscle and its surrounding part as near the cornea as possible, and firmly fixing them there."

After exposing the muscle the surgeon inserts two threads, one through the upper and one through the lower border of the muscle, more or less behind its attachment according to the effect desired. After division of the tendon the threads are passed under the superior and inferior borders of the cornea, and, when necessary, as far as its vertical diameter. The threads are then knotted, bringing the tendon forward toward the corneal margin. An assistant turns the eyeball in the direction of the muscle to be advanced. When resection of the muscle is necessary, allowance for this is made before the muscle is cut off, and then that portion of the muscle still adherent to the tendon is removed.

Landoll's argument for advancement is that " it causes the eye to enter its muscular investment, from which the tenotomy causes it to escape." He does the operation in cases of strabismus in preference to tenotomy. Since advancement is so seldom followed by any reaction, he believes that it will come into more general use for strabismus.

The writer believes that this method of operating will be and should be more generally adopted. With the present aseptic precautions, it is no more dangerous than a simple tenotomy, although more difficult. The final cosmetic results will be more satisfactory. It better preserves the function of the muscle and prevents any advancement of the eye.

(g) Stevens's Operation of Tendon shortening or Advancement. Dr. Stevens's operation for advancement is as follows: The opening in the conjunctiva is the same as for tenotomy (page 589). Then, lifting the border of the conjunctiva nearest the cornea by the fine forceps, a little pocket is made by the points of the scissors or the lance probe (Fig. 406, D), extending under the conjunctiva more or less toward the cornea in proportion to the greater or less effect which we propose to induce. The forceps seizes the central portion of the tendon, and it is dissected from the eyeball entirely or partially as the case may be. The fine tendon crochet (Fig. 406, F) or the fixation forceps with catch now seizes the tendon behind the section and draws it forward through the conjunctival opening, when one needle on a double armed thread is passed through the central portion of it from 1 to 1 min. behind the cut extremity. The other needle is made to penetrate the conjunctiva at the extreme end of the pocket and the thread drawn through. Another thread is inserted in a similar manner a little to one side of the first, in order to allow between the two threads a little bridge of tissue. Now the surgeon draws upon the ends of the threads, forcing the cut end of the tendon into the little pocket, and fastens the threads by tying them across the little bridge. The sutures are removed on the third or fourth day.

Choice of an Operation. The choice of an operation will depend much on the method one has practised or has seen practised. No one method has all the good qualities to recommend it, but, as all are intended to accomplish the same purpose, the surgeon can choose the one best suited to his own ideas. The method of resecting the muscle as performed by Sehweigger, Noyes, and others produces excellent results. In this way the muscle is permanently shortened, and the cut end of the muscle attaches itself to the sclera at the point where the original insertion existed. It is not, however, always necessary to resect the muscle. In Noyes's operation the thread is passed underneath the conjunctiva of the severed muscle. It is probable that the Noyes operation is freer from the possibilities of danger than Schweigger's, owing to the deep insertion Of the needle in the sclera in the latter. The former is the one the writer prefers, but he considers the two threads in the upper and lower edges of the muscle sufficient, without the use of the third or middle thread. In the limited space allowed it has been impossible to mention man of the operations devised by different surgeons. A choice bad to be made from the many and it intended discourtesy to those omitted.

IV. Advancement of the Capsule; de Wecker's Method. This operation is performed as follows :

A vertical incision as long as the corneal diameter is made through the conjunctiva over the tendon. The excision of a halfmoon shaped piece of conjunctiva is only necessary in very high degree of deviation. An opening in the capsule is made, and through this the hook is inserted from above downward. The hook is passed completely under the tendon until its point is free on the opposite side. At the same time the capsule is incised above and below. Next, two double armed threads are employed in the following way: One end of the thread is passed through the incision in the capsule from the inner surface, so that it pierces muscle, capsule, and conjunctiva. The point at which the muscle is pierced is regulated by the effect to be produced. The other end of the thread is carried through the incision under Tenon's capsule forward toward the corneal margin, through the superficial layers of the sclera, until it emerges from the conjunctiva at the vertical meridian of the eye, about 5 mm. from the cornea. There the two threads are tied simultaneously by the operator and his assistant. A surgical knot is first made, and when the eye is in position the double knot is completed. The conjunctiva is then closed by three sutures.

Knapp modifies this operation by the use of a third, middle suture passed through the equatorial flap of the conjunctiva, through the tendon (which was held up, drawn forward, and folded with a squint hook), underneath the squint book, and through the episcleral tissue and the flap of conjunctiva near the cornea.

Advancement of the capsule is inferior to the advancement or resection operations described above. It leaves, for a while at least, an ugly knot or elevation under the conjunctiva, and its final results are not as certain and free from danger as other methods.

Accidents and Complications. Subconjunctival hemorrhage is more or less abundant in every case of tenotomy or advancement, but it is readily absorbed and needs no treatment other than the use of hot fomentations.

Retrobulbar hemorrhage or hemorrhage into Tenon's capsule occurs occasionally. It is not likely to lead to serious results, but may vitiate the immediate effects of the operation. A compress bandage should be applied over the eye, and on this iced compresses laid and changed frequently. Retrobulbar hemorrhage may be caused by vomiting during anesthesia.

Granulations occasionally spring from the incision in the conjunctiva. They are readily controlled by snipping them off with scissors close to the sclera or touching them with' a crystal of copper sulphate or alum. Dr. Noyes reports a case where diphtheritic inflammation attacked the wound after a strabismus operation, and resulted in divergence.

Ulceration of the margin of the cornea from the end of the thread, which was cut off too long, occurred in the experience of the writer. It was promptly relieved by cutting, off the thread. The breaking of a thread during an advancement operation is a very uncomfortable accident. It should be avoided by carefully testing the thread, which should be strong enough to stand the traction.

Panophthalmitis and orbital inflammation have been known to follow advancement operations, but the occurrence is extremely rare. Perforation of the sclerotic during the operation for strabismus occurs occasionally, even in the hands of the most skilful operators. Cases are reported by Drs. Masker, Derby, Knapp, E. Williams, and others. Panophthalmitis has followed this accident.

Instruments and dressings for an ordinary tenotomy of one of the recti muscles are a spring speculum, two pairs of fixation forceps (Fig. 410), two strabismus hooks (Fig. 411), the one smaller than the other, two pairs of scissors, one curved (Fig. 412) and one straight (Fig. 413), a needle holder (Fig. 414), and two or three needles threaded with fine black silk which has been waxed, absorbent cotton sponges, and dry absorbent cot ton, fine gauze bandages, and a compress.

As the cornea becomes dry during exposure from the influence of cocain, it is well to have a dropper and some sterilized water in a glass dish close by, so that the cornea can be moistened in case it is necessary.

For advancement operations, in addition to the above, it is necessary to have long black silk tbread or catgut sutures, armed with two or three needles, as described in the various methods devised by different operators.

Local anesthesia by cocain is much more desirable than general anesthesia, for the reason that the effects can be at once tested and any under or overcorrection remedied; but in children it may be necessary to administer an anesthetic. It is especially desirable to operate for advancement under cocain, for we want the aid of the patient to determine the effect produced. Eucain is recommended by Silex in squint operations.

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