CHAPTER IV

OPERATIONS UPON THE SCLEROTIC

ANTERIOR SCLEROTOMY

=Indications.= Sclerotomy is an operation undertaken for the relief of increased intra-ocular tension. It is performed--

(i) Usually as a secondary operation when iridectomy has failed.

(ii) As a primary operation for the division of anterior synechiæ causing tension.

A few surgeons prefer the operation to iridectomy, especially in cases of bup[h]thalmos. When practised after an iridectomy which has been done upwards, the sclerotomy is sometimes performed in a downward direction; otherwise the section is usually made upwards. The intra-ocular tension is probably relieved by the formation of a filtration cicatrix, and it is therefore probable that it may be largely superseded by the operations of cyclo-dialysis and sclerectomy.

When performed for the division of anterior synechiæ the position of the incision should be planned according to the situation of the synechia to be divided.

=Instruments.= Speculum, fixation forceps, Graefe’s knife with a narrow blade.

=Operation.= The operation is done under cocaine. Eserine should have been previously instilled in order to contract the pupil and prevent prolapse of the iris.

Graefe’s knife should be passed across the anterior chamber in the same manner and position as for a glaucoma iridectomy (see p. 221). In the _complete_ method the knife is made to cut out through the sclerotic, leaving a band of conjunctiva to hold the flap in position. In the _incomplete_ method a band of sclerotic is left in the periphery. If the operation is done in a downward direction, it is better for the surgeon to stand on the opposite side of the patient to the eye on which the operation is to be performed, operating across the patient.

=Complications.= Any of the complications which follow an iridectomy for glaucoma may occur (see p. 222). Prolapse of the iris is probably the most frequent.

CYCLO-DIALYSIS

=Indications.= This operation has only recently come into general use in this country, so that statistical results have at present by no means been worked out, but most satisfactory results have been obtained from it in individual cases; according to German authorities about 30 per cent. are permanently cured. Although at present its performance is largely limited to blind eyes and to eyes that have undergone previous operations for glaucoma, it is probable that it may come into further use as a primary operation in the treatment of chronic glaucoma and bup[h]thalmos. It is also of service in cases of dislocation of the lens backwards, associated with increased tension, where iridectomy would certainly be followed by loss of the vitreous.

The operation has for its object the separation of the ligamentum pectinatum from its attachment to the sclerotic, with the probable result that the ciliary body and iris root become retracted by the ciliary muscle, so that the canal of Schlemm is opened up and again communicates with the anterior chamber. It also opens up a free communication between the anterior chamber and the suprachoroidal lymph-spaces. The reduction of tension is often not fully manifest for about ten days after the operation.

=Instruments.= Speculum, fixation forceps, Graefe’s knife, fine pair of straight iris forceps, fine pair of sharp-pointed straight scissors, iris spatula.

=Operation.= The operation is best performed under a general anæsthetic, as it is attended with considerable pain, although cocaine and adrenalin are frequently used and are always advisable, since the hæmorrhage from the scleral vessels renders it difficult to gauge the depth of the wound in the sclerotic.

_First step._ By means of the straight iris forceps and sharp-pointed scissors a semilunar conjunctival flap is first raised over the site for the scleral incision. The incision in the sclerotic should be situated about 5 mm. behind the corneo-sclerotic junction over the ciliary region, the outer and upper quadrant of the eye being the easiest position for subsequent manipulation (Fig. 119).

_Second step._ With a Graefe’s knife the fibres of the sclerotic are carefully divided in an oblique direction forward until the suprachoroidal lymph-space is opened for about 3 mm. The first part of the incision is performed with the blade and completed with the point of the knife, the anterior flap of sclerotic being held forward by straight iris forceps. Heine uses a keratome, dividing the fibres of the sclerotic with the point by stroking it along the line of the incision. The depth of the incision should be carefully gauged from time to time with the iris spatula; the pigment of the ciliary body is usually seen in the bottom of the wound when the sclerotic has been penetrated.

_Third step._ The iris spatula is directed forwards and inserted between the sclerotic and the ciliary body, keeping close to the former. With a gentle side-to-side movement the spatula is made to separate the ciliary body from the sclerotic for about one-eighth of its whole circumference; then the ligamentum pectinatum is detached from the sclerotic for about the same distance by gently passing the spatula forwards and making the latter appear in the anterior chamber (Fig. 120). If it be desired to evacuate the anterior chamber, the spatula is slightly rotated so as to allow the escape of the aqueous. As a rule this is not necessary or even advisable. The spatula is then withdrawn and the conjunctival flap is replaced in position. Eserine should be instilled.

=Complications.= (1) Unless the incision be carried carefully through the sclerotic, or the manipulations with the iris spatula be very gentle, loss of vitreous is liable to take place. As a rule, this, if not great, is of little consequence. (2) In passing the iris spatula forward to separate the ligamentum pectinatum the point may pass between the layers of the cornea; this is recognized in the resistance offered to the side-to-side movement of the spatula, which should be withdrawn slightly and the point depressed so as to engage the ligamentum pectinatum. (3) Subchoroidal hæmorrhage has been known to occur after the operation.

SCLERECTOMY

The object of the operation is the production of a filtration cicatrix free from iris tissue for the relief of intra-ocular tension in chronic glaucoma.

=Instruments.= As for glaucoma iridectomy, with the addition of a small curved pair of scissors.

=Operation.= Under cocaine.

_First step._ The incision is performed as for glaucoma iridectomy (see p. 221), except that the incision should be rather smaller and should be carried more obliquely through the sclerotic, so that a long scleral flap is obtained. A large conjunctival flap is very essential to cover the wound.

_Second step._ An iridectomy is usually performed as for glaucoma; this may be omitted.

_Third step._ After all the bleeding has ceased, the conjunctival flap is turned forwards on to the cornea so as to expose the scleral flap; with small curved scissors made for the purpose, an elliptical portion is removed from the sclerotic by a single snip (Figs. 121 and 122), and the conjunctival flap is replaced in position. As a result, a hole is made into the anterior chamber, which thus communicates with the subconjunctival tissue, which is bulged forwards in the form of a clear vesicle by the escaping aqueous when the wound has healed.

The immediate results of this operation are satisfactory provided that enough sclerotic be removed to produce a filtration cicatrix. As yet sufficient time has not elapsed for any statistical results to be obtained, but the cases in which the operation has been performed are reported as satisfactory.

POSTERIOR SCLEROTOMY

=Indications.= Posterior scleral puncture is performed--

(i) For the relief of tension, the indications for which have already been described under the indications for iridectomy in glaucoma (see p. 218).

(ii) For the evacuation of fluid behind a detached retina.

The operation in the latter instance, although not yielding very satisfactory results with regard to the reattachment of the retina, may be carried out with some hope of success in certain cases. Before performing the operation the pathological cause of the detachment should be carefully investigated, for it is obvious that it would be useless to perform the operation in a case of detachment due to a choroidal tumour or if definite bands of fibrous tissue could be seen in the vitreous pulling off the retina. Undoubtedly it should be undertaken as soon as possible after the detachment has occurred and the puncture should enter the space filled with subretinal fluid. Whether the puncture should penetrate the overlying retina is still a disputed point.

After the operation a pressure bandage should be applied and the patient should be kept on his back and not allowed to raise his head from the pillow for at least three weeks. This latter part of the treatment is most essential; indeed as good results may be obtained with complete rest as by performing scleral puncture. Unfortunately, recurrence is very liable to take place whichever method be used, even if reattachment of the retina be obtained.

=Instruments.= Speculum, fixation forceps, Graefe’s knife.

=Operation.= Under cocaine. If no special position be indicated the puncture is best made upwards and inwards. The patient is made to look outwards and downwards. The conjunctiva over the sclerotic, well behind the ciliary body, is drawn down so that when released it shall form a valvular opening to the scleral wound. The Graefe’s knife is driven through the conjunctiva and sclerotic, the incision being made antero-posteriorly in the direction of the fibres of the sclerotic to avoid wounding the choroidal vessels. It is probably better to enlarge the wound when withdrawing the knife than to turn the latter at right angles before it is withdrawn, as has been recommended by some surgeons. A bead of vitreous usually escapes under the conjunctiva. If the tension be not lowered, gentle massage of the globe through the lid should be employed.

PARACENTESIS OF THE ANTERIOR CHAMBER

=Indications.= Evacuation of the contents of the anterior chamber is performed for several conditions:--

(i) To reduce the tension of the eye when due to an altered consistency of the aqueous, as for instance in cyclitis.

(ii) To evacuate pus from the anterior chamber following metastatic infection.

(iii) To evacuate the anterior chamber in bad corneal ulceration, especially when associated with hypopyon and tension.

(iv) To examine the aqueous for organisms in cases of cyclitis following operation or of metastatic origin.

(v) To evacuate soft lens matter (see p. 194).

The operation is usually performed through an incision directly behind the limbus. In the case of corneal ulceration it is sometimes performed by dividing the base of the ulcer with a Graefe’s knife (Sämisch’s section). When collecting the aqueous for bacteriological examination, a sterile hollow needle with a point similar to a discission needle, attached to a hypodermic syringe, should be passed into the anterior chamber at the limbus and the fluid withdrawn into the syringe by an assistant (Fig. 123). The spot through which the needle is passed is first touched with the electro-cautery to ensure asepsis.

=Instruments.= Speculum, fixation forceps, bent broad needle, iris spatula.

=Operation.= Under cocaine. The puncture is usually made upwards and outwards unless there be some other special indication for its position, such as a mass of pus in the lower angle of the anterior chamber. The eye is fixed opposite the spot at which the puncture is to be made, and the bent broad needle is passed into the anterior chamber through an incision directly behind the limbus. The needle is then withdrawn and is usually followed by a rush of aqueous. The remainder of the aqueous is then evacuated by pressing the lower margin of the wound with an iris spatula. In some cases where a very tenacious hypopyon is present it may be withdrawn with the iris forceps. The only complication liable to occur is prolapse of the iris into the wound, which should be replaced with the spatula, or failing that, removed.

OPERATIONS FOR PENETRATING WOUNDS OF THE GLOBE

=Indications.= Of all the conditions which a surgeon is called upon to see, penetrating wounds of the globe may present the most difficult problems as to treatment. The most important factors in their treatment and prognosis are--

1. _The time at which the patient presents himself for treatment_ and the condition of the wound are all-important in the prognosis. Thus in the case of a wound which is obviously septic and going to terminate in panophthalmitis the eye should be eviscerated.

2. _The position and extent of the wound._ Formerly it was taught that if the ciliary body were wounded the eye should be excised. The reason for this was that these injuries were so frequently followed by sympathetic ophthalmia owing to prolapse of the iris and ciliary body. It is now generally recognized that sympathetic ophthalmia only follows if the wound becomes septic, irido-cyclitis with keratitis punctata being present, and it is only after the latter symptom manifests itself that the eye should be excised, provided that the wound be not so extensive as to preclude all chance of recovery from the outset.

_In wounds of the sclerotic_ all portions of the uveal tract and vitreous which prolapse should be removed, and the wound closed with sutures passed through the superficial episcleral tissue. Unless the wound be small the prognosis is not good, as it is liable to be followed by irido-cyclitis, or, if this does not occur, detachment of the retina may ensue, following on organization of the exudates in the vitreous.

_Wounds of the cornea_ usually result in prolapse of the iris, which should be removed in the manner described under iridectomy (see p. 208).

3. _If the lens be injured._ Unless the wound amounts to little more than a punctured wound of the globe involving the lens, the prognosis is bad. The wound in the lens capsule and the breaking up of the lens mean the presence of soft matter in the anterior chamber--a condition which favours sepsis and is liable to produce increased tension from blocking the angle of the chamber. In patients under thirty the pupil should be dilated with atropine and the lens allowed to absorb--assisted at a later date by needling, when the eye has entirely settled down after the original injury. If the patient be over thirty it is often extremely difficult to decide whether extraction of the lens should be undertaken at the time of the injury or at a later date. The results of both procedures are very unsatisfactory, and the surgeon should be guided partly by the position and extent of the wound. Given these in a fairly favourable position, it is probable that immediate extraction will give the best result.

4. _If the eye contain a foreign body._ Usually these are pieces of metal or glass. The following points should be investigated to determine whether the foreign body be in the eye:--

(i) The history of these accidents is usually the same. The patient is chipping with a hammer and chisel, and a piece flies off and strikes the globe. In the case of glass it is usually a mineral-water bottle which bursts.

(ii) The position and nature of the wound in the cornea and sclerotic.

(iii) The condition of the anterior chamber--whether evacuated or not.

(iv) The tension of the eye, which may be lowered.

(v) The presence of a hole in the iris.

(vi) The presence of traumatic cataract.

(vii) Whether the foreign body is visible with the ophthalmoscope or by focal illumination.

(viii) The localization of the foreign body by the X-rays. The latter is the most important factor of all, since the foreign body may pass right through the globe and be embedded in the orbit.

=Operative treatment.= If the injury be a recent one and the foreign body a metal of magnetizable properties, it is best removed by an electro-magnet after localization by the X-rays (Fig. 124). Sideroscopes have been used, but are not so satisfactory. If the foreign body be non-magnetizable, such as a piece of copper cap or manganese steel, an attempt may be made to remove it with forceps after localization. If the foreign body be embedded in the lens it is often advisable to extract the lens together with it. If the foreign body be of glass, and it be only small, it is usually best left alone, unless capable of easy removal, _e.g._ if it be situated in the anterior chamber; the eye will often tolerate the presence of glass provided it be aseptic.

_The eye should be removed_--

(i) If the wound be obviously septic.

(ii) If the wound be very large, more especially if the lens be injured.

(iii) If the foreign body be a large piece of metal and cannot be extracted.

(iv) If the eye does not settle down after one of the operations described below, especially if irido-cyclitis with keratitis punctata should have supervened.

=If the injury be of long standing.= It is of little use as a rule attempting to extract a foreign body from the eye after three days, unless it be loose in the vitreous or embedded in the lens, as it becomes surrounded by lymph. Under these circumstances it is better to leave it alone, or, if it be causing signs of irritation, to enucleate the eye.

ELECTRO-MAGNET OPERATIONS

Magnets for the removal of magnetizable foreign bodies from the eye are of two types--(1) a small magnet, which is inserted into the globe, (2) a giant magnet, which is used to attract the foreign body in the eye from the outside.

Surgeons differ as to which is the best method to employ. The statistical results of both are about the same. Many surgeons in this country, and with them the author, prefer the small magnet, especially of the recent more powerful type (Hirschberg), which runs off the main electric current, for the following reasons: it is more accurate (after localization by the X-rays), there is less trauma to the globe involved, it is more portable, and, when the foreign body is in the anterior or the posterior chamber, it is much easier to extract it with a small magnet than with a large one.

=With the small magnet. Instruments.= Beer’s knife, fixation forceps, magnet (Fig. 125), and suture. The points of the magnet, which are detachable, are sterilized by boiling.

=Operation.= The foreign body is first localized accurately by means of the X-rays. If it lies near the wound of entrance the magnet point is inserted, the electric circuit completed, and the foreign body withdrawn, the wound of entrance being enlarged if necessary. If the foreign body lies at some distance from the wound, as for instance in the vitreous, an antero-posterior incision is made in the sclerotic, as near to it as possible, by plunging the knife through the conjunctiva and the sclerotic, the former having previously been drawn to one side so as to form a valvular opening. The size of the incision should be such that it will admit the point of the magnet and allow the foreign body to come out, the size of the foreign body being judged by the X-ray photograph. After the knife has been withdrawn, the point of the electro-magnet is inserted and the circuit closed, the magnet being withdrawn with the foreign body attached to it. The conjunctival wound is closed by a suture if necessary. If the foreign body be situated in the anterior or posterior chamber or the lens, an incision should be made into the anterior chamber with a keratome, the point of the magnet inserted, and the foreign body withdrawn. In cases in which the foreign body is deeply embedded in the lens, more especially in patients over thirty years of age, extraction of the lens together with the foreign body should be performed.

=Complications.= _Immediate._ Failure to extract the foreign body may arise from--

1. The foreign body being embedded in lymph. It is therefore of the utmost importance that the operation should be performed as soon as possible after the injury.

2. The foreign body being deeply embedded in the sclerotic so that the magnet will not exert sufficient traction to withdraw it.

3. The foreign body being non-magnetic (all steel is not magnetic).

4. Too small a wound being made for its extraction, the metal being wiped off on the edges of the wound as the magnet is withdrawn.

5. Insufficient power in the magnet.

_Remote._ 1. Panophthalmitis, which must be treated by evisceration.

2. Irido-cyclitis; if this be prolonged, and keratitis punctata appear, enucleation should be performed.

3. Traumatic cataract; this may subsequently require needling.

4. Detached retina as the result of organization in the vitreous; this may occur months after the original injury.

=With the giant magnet.= The foreign body should have been previously localized by the X-rays, and its position and size determined, so that it may be removed by the shortest possible route and with the least amount of injury to the eye.

=Instruments.= Giant magnet (Fig. 126), steel spatula. (Watches and magnetizable metal should be removed from both the patient and the surgeon.)

=Operation.= Under atropine and cocaine. The patient is at first seated in a chair some three feet in front of the magnet, the eyelids being held apart by the surgeon; the electric circuit is closed. The patient’s head is next gradually advanced towards the magnet. If a foreign body be present in the eye and be magnetizable, the patient will usually withdraw his head or cry out with pain, and the foreign body may be seen bulging forward the iris from the posterior chamber. From this position it may be removed by manipulating the head and eye in relation to the magnet so as to withdraw it into the anterior chamber, from whence it is removed through the entrance wound or an incision at the limbus either by the giant magnet directly applied to the wound or by magnetizing a steel spatula which is inserted into the anterior chamber and connected with the magnet by a flexible steel cable. The small magnet previously described may be used, or the foreign body removed by means of iris forceps.

A piece of steel in the vitreous always travels round the posterior surface of the lens and through the suspensory ligament, and does not injure the lens capsule.

=Complications.= These are similar to those described under the small magnet operation.