CHAPTER I

GENERAL CONSIDERATIONS APPLICABLE TO OPERATIONS UPON THE EYE

Operations upon the eye differ so widely from general surgical operations that it is necessary to say something of the preparations for them before pa.s.sing on to their actual performance. Although not formidable in themselves, they require great accuracy and presence of mind; slight mistakes, such as too small an incision, may cost the patient his sight, which sometimes may be almost more important than life itself.

Most intra-ocular operations are performed without general anaesthesia; it is therefore important that the patient should be given confidence by talking to him during the operation, so that he may follow the instructions of the surgeon during its performance; loss of self-control on the part of the patient, movement of the head, s.c.r.e.w.i.n.g up of the eyes, &c., may lead to disastrous results, however well performed the operation itself may be.

GENERAL PRELIMINARIES TO AN OPERATION

_The urine_ should always be examined, especially in cases of cataract, as not infrequently this disease is a.s.sociated with diabetes, and it is often advisable to treat the general condition before operation.

_The bowels_ should be opened by an aperient the night before the operation, as it is desirable to keep them confined for the first two days afterwards, so as to avoid straining. During the first week after a major operation, when the patient is confined to bed, they should be evacuated in the supine position.

_The best time_ for operating, if possible, is the morning, as the patient has had a night's rest and is less likely to lose self-control.

Usually there is some pain after the cocaine has gone off, and the patient is better able to stand it during the daytime.

_Anaesthetics._ _General_ anaesthesia should be induced in all patients with congested eyes, in small children, patients who are deaf, and those who show a want of self-control. Chloroform should be used for all intra-ocular operations, and should be given to the full surgical degree. It should be given on a towel or an inverted mask specially made for the purpose, a Junker's inhaler being used during the time the actual operation is being performed. As the surgeon usually stands at the head of the patient, the anaesthetist should stand on the side away from the eye being operated on. The local use of cocaine in addition to general anaesthesia is indicated when operating on patients to whom it is advisable to give as little anaesthetic as possible.

[Ill.u.s.tration: FIG. 74. WINDOW OF THE OPERATING THEATRE, KING'S COLLEGE HOSPITAL. The windows are fitted with outside blinds so that either can be used separately, or the surgeon may stand in the angle and operate with his back to the light. A recess beneath the window allows the patient's face to be brought close to the light on dark days.]

_Local_ anaesthesia is obtained by the use of a 4% solution of cocaine instilled four or five times before the operation at intervals of three minutes; a drop of the solution should also be instilled into the eye which is not being operated on, to prevent an accidental reflex stimulation of the conjunctiva and s.c.r.e.w.i.n.g up of the eyes. Adrenalin (1-1,000) may be used in conjunction with the cocaine; it is especially useful in squint operations, as it lessens the haemorrhage. Eucaine and stovaine have been used, but are not nearly so satisfactory. Under ordinary circ.u.mstances the only pain felt during an intra-ocular operation is during removal of the iris; this is obviated to a great extent by instilling the cocaine at least 15 minutes before the operation is performed, so as to allow time for its diffusion into the anterior chamber. The patient should be warned when to expect the pain, so that he may not move; his self-control may be tested beforehand by p.r.i.c.king the nose with a pin.

_The theatre._ The theatre should possess, as far as possible, all the modern improvements found in an up-to-date general surgical operating-room. The light should proceed from a single large window, which, if possible, should face the north. _The window_ should consist of a single pane of gla.s.s or of two panes forming the angle of the theatre; it should begin about 5 feet from the floor and should extend to the ceiling (Fig. 74). The advantage of an angular window is that it allows the operator to stand with his back to the light in the angle, and so enables onlookers to see. No top light should be allowed, as it produces a corneal reflection which may prevent the operator from seeing the position of his knife in the anterior chamber. Beneath the window there should be a recess for the end of the operating table, so that the patient's face can be brought close to the window if necessary (Fig.

74). This recess is formed by building the main wall of the theatre further out than the window, which has to be supported by a transverse girder.

[Ill.u.s.tration: FIG. 75. BULL'S-EYE ELECTRIC HAND-LAMP. For use when artificial illumination is required.]

The window should be fitted with outside blinds so that the theatre can be easily darkened for the operations, such as capsulotomy, which require the use of artificial light. The best artificial light is a small enclosed electric hand-lamp fitted with a bull's-eye, by means of which the operation field can be brilliantly illuminated while the surrounding area is left in comparative darkness (Fig. 75). Failing this, a single powerful lamp with a ground-gla.s.s globe, placed in front of the patient, will serve, the rays of light being brought to a focus on the eye by means of a large convex lens of about + 10 D.

For _squint operations_ it is desirable to have a light fixed to the ceiling, directly over the head of the operating table, for testing the position of the eyes either by the reflection of the light from the surface of the cornea or by the Maddox rod test.

_The operating table_ should be provided with a means of adjusting its height and the position of the head-piece, so that the patient's head can be brought to about the level of the operator's elbows when the latter is standing upright with his arms at his side.

_After operation_ the patient should be warned to lie still and not to strain in any way; he should be carried to bed and should lie on his back if possible. If a patient cannot sleep on his back it is better that he should lie on the sound side than be without rest. A length of bandage should be fastened round the wrist of the hand on the same side as the eye which has been operated upon, and should be attached to the bed so as to prevent the hand being put up to the eye during sleep.

After major operations, such as those for cataract and glaucoma, the patient is confined to bed for ten days, during the first four of which the head should not be raised from the pillow, the bowels being evacuated while the patient is in the supine position; but old patients with a tendency to bronchitis or hypostatic pneumonia must be propped up in bed and allowed to get up earlier: in these patients it is better to perform the operation in the summer if possible. In old people and patients with a tendency to melancholia the mental condition must be carefully watched, as frequently they cannot stand the confinement to bed and darkness.

LOCAL PREPARATION OF THE PATIENT

When operating upon the eye, a surgeon has to face the great difficulty that he is operating in an area which is not always aseptic, since it is practically impossible to render the conjunctival sac sterile. At the same time, the conjunctiva has been shown to be sterile in health in 25% of cases, pyogenic organisms (princ.i.p.ally the staphylococcus albus) being found only in 15%; but, although these are usually not of a very virulent character, they are by far the most frequent cause of sepsis; ten cases of suppuration after operation which the author has examined were all due to this organism. After the methods of purification given below, this percentage is considerably reduced, so that, if due precautions are taken, the risk of sepsis is comparatively small. On the other hand, if conjunctivitis or lachrymal obstruction be present, the risks are enormously increased, especially in the latter condition owing to the frequent presence of the pneumococcus in the discharge, unless special precautions are taken. It is, therefore, of the utmost importance that every case should be examined for lachrymal obstruction before operation. Care should be taken also to see that there is no purulent discharge from the nose or any septic sores about the face.

Sepsis after intra-ocular operations manifests itself in one of two forms: either by suppuration, which usually ends in a rapid and complete destruction of the eye (panophthalmitis), or more rarely in less virulent cases by recurrent attacks of hypopyon a.s.sociated with acute irido-cyc.l.i.tis; or by a plastic irido-cyc.l.i.tis, which may lead to slow disorganization of the eye, with always the possibility of destruction of the other eye by sympathetic cyc.l.i.tis (sympathetic ophthalmia).

Although these conditions are comparatively rare, owing to the improvement in modern aseptic and antiseptic methods, every surgeon of experience will meet with these disastrous complications; indeed it has been suggested that immunization with staphylococcus vaccine should be carried out before major intra-ocular operations, since infection is generally due to this organism.

[Ill.u.s.tration: FIG. 76. LANG'S EYE SPECULUM. Designed to hold the lashes away from the field of operation.]

_The methods of purifying the eye before operation._ On the second night previous to the operation the eye should be bandaged and examined the following morning for conjunctival discharge. If any be present, an examination for organisms should be made, and the operation postponed until the conjunctival condition has improved. In the event of the case being extremely urgent, the conjunctiva should be swabbed over with nitrate of silver (10 gr. to the oz.) immediately before the operation; some surgeons prefer 1-2,000 perchloride of mercury. If lachrymal obstruction be present, the sac should be thoroughly washed out with boric lotion and protargol (10%) injected. The ca.n.a.liculi may be temporarily occluded subsequently (see p. 294). If the lashes be very long they should be cut short. Epilation is performed by some Continental surgeons, but is not practised in this country. Various forms of specula are made to keep the lashes out of the field of operation; of these, a modification of Lang's is perhaps the best (Fig.

76).

On the morning of the operation the lids should be thoroughly cleansed with soap and water, followed by 1-2,000 solution of perchloride of mercury, special attention being paid to the lid margins and lashes. The conjunctival sac should be washed out with boric lotion and a pad of cyanide gauze applied over the closed lid.

GENERAL CONSIDERATIONS AS TO MAKING AND HEALING OF WOUNDS IN THE GLOBE

It has already been pointed out that the great danger in intra-ocular operations is sepsis. It is the aim and object of every ophthalmic surgeon to make such wounds into the globe as will become rapidly shut off from the conjunctival sac. Delay in the healing tends to the formation of a fistulous opening into the globe. This aperture in the continuity of the globe may lead either directly on to the surface or beneath the conjunctiva, subsequent inflammation in which may spread to the interior of the eye.

[Ill.u.s.tration: FIG. 77. UNDINE FOR WASHING OUT THE CONJUNCTIVAL SAC.]

_Cocaine_ and other solutions used at the time and subsequently to operation should be sterilized. To ensure this the solutions should either be boiled immediately before use, or put up in drop bottles made in one piece with a long tapering neck, which is sealed off, and can be broken immediately before use. These bottles can be kept in an aseptic solution so as not to soil the hands of the surgeon.

_The hands_ of the surgeon are purified. After the dressings have been removed, the patient's head and the area surrounding the operation are covered with sterilized towels. In operations such as advancement, where sutures are used, it is desirable that the face should be covered with sterile muslin, with a hole cut in it for the eye, so as to prevent the sutures being contaminated from the skin of the face. The eyelids are again washed in 1-2,000 perchloride of mercury lotion, and the conjunctival sac is washed out with a strong stream of boric lotion or normal saline by means of a sterilized irrigator or an undine (Fig. 77) which has been kept in a bowl of lotion.

_Instruments._ Non-cutting instruments are boiled for 15 minutes in distilled water and placed in a tray of 1-80 carbolic lotion. Some surgeons prefer to place the instruments in the tray without lotion on sterile wet lint, as this excludes infection from the surgeon's hands due to the lotion running off them on to the instrument. Failing distilled water, a small quant.i.ty of soda may be added to the water used for boiling, but this has the disadvantage that a deposit is liable to form on the instruments. This may be obviated to a certain extent by not placing them in the solution until it is boiling. Cutting instruments should be sterilized by dipping them in liquefied carbolic acid (crystals dissolved by heating with 10% of water) for half a minute immediately prior to use and then into absolute alcohol to remove the acid; they are then placed in the tray. The greatest care should be taken to see that cutting instruments and needles do not touch the side of the dish. The edges and points should always be carefully tested immediately before sterilization on a drum covered with fine kid specially made for the purpose. The points should pa.s.s through the drum by the weight of the instrument held flat on the open palm; the cutting edge should also be tested. Scissors are best tested by cutting wet cigarette paper, special care being taken to see that the edges are good near the points. Immediately after operation the instruments should be boiled, and dried whilst hot in order to prevent rust.

[Ill.u.s.tration: FIG. 78. CATARACT EXTRACTION. The drawing shows the line of incision. Note the conjunctival flap.]

_The direction of an incision_ into the globe should be as oblique as is consistent with the object of the operation, so as to allow larger healing surfaces to come into apposition. With this object in view it is desirable that a conjunctival flap should be formed to all wounds wherever possible (Fig. 78). Further, owing to the extreme vascularity of the conjunctiva, as has been shown elsewhere,[3] wounds in it become firmly united after 48 hours. As a rule sutures are best avoided and are seldom required.

[3] Mayou, _Hunterian Lectures_, 1905.

_Position of the incisions._ Corneal incisions are to be avoided, if possible, for the following reasons: firstly, the cornea being free from blood-vessels heals comparatively slowly; secondly, the wound is liable to become fistulous owing to the rapidity with which the epithelium grows down the side of the wound. On the other hand, incisions situated from 3 to 6 millimetres behind the limbus are liable to injure the ciliary body, and, in addition to irido-cyc.l.i.tis being set up by the trauma, the iris or ciliary body will prolapse into the wound and prevent the union of its edges, with the result that sepsis may spread into the globe along the prolapsed portion of the uveal tract and set up an irido-cyc.l.i.tis which may not only ruin the eye affected but may also cause a sympathetic irido-cyc.l.i.tis in the other eye (Fig. 79).

[Ill.u.s.tration: FIG. 79. SYMPATHETIC OPHTHALMIA. The exciting eye of a case following cataract extraction. The section shows the incarceration of the iris in the wound.]

[Ill.u.s.tration: FIG. 80. CYSTOID SCAR AFTER GLAUCOMA IRIDECT]

_The site of election of an incision_ into the anterior part of the globe is therefore about 1 millimetre behind the limbus; that is to say, as near the cornea as is consistent with obtaining a good conjunctival flap to cover the wound in the globe (Fig. 78). When possible it is advisable to make all incisions in an upward direction for the following reasons: They are more easily performed; any deformities, such as an iridectomy, are hidden by the upper lid; more perfect rest is obtained, as the wound is not exposed in the palpebral aperture, the eye being turned upwards when the lids are closed.

[Ill.u.s.tration: FIG. 81. AN EYE BANDAGE. The first turn, A, encircles the head and is fixed with a pin. This portion of the bandage can be put on before the operation and obviates movement of the head. The turn B is then brought up below the ear and fixed with pins.]

[Ill.u.s.tration: FIG. 82. A PRESSURE BANDAGE. The first turn of a 1-1/2-inch bandage encircles the head. It is then carried beneath the ear and over the head in a figure-of-eight. The final turn goes round the head and is fixed by a pin at the point of crossing of the previous turns.]

The immediate danger of the pa.s.sage of a knife into the anterior chamber of the eye is the wounding of the lens. To avoid this the point of the knife should be always kept superficial to the iris if a clear lens be present in the eye. After operation the chief danger is prolapse of the iris into the wound. This is best avoided at the time of operation by carefully replacing the iris with the spatula at the end of the operation, but unfortunately prolapse not infrequently occurs during the first few days owing to the reacc.u.mulation of the aqueous in the anterior chamber and its sudden escape through the imperfectly healed wound as the result of straining or of some movement on the part of the patient; the iris may be carried into the wound with the escaping aqueous, and a fistulous opening or a scar may form subsequently (Fig.

80).

The less manipulation used consistent with the object of the operation the less likelihood is there of cyc.l.i.tis following it. All instruments should be held lightly in the fingers, which should be as far as possible responsible for the fine manipulation required. The part of the hand not actually holding the instrument should be steadied on the face before the instrument is brought in contact with the eye.

When more than one operation has to be performed on the same eye it is desirable that all ciliary injection after the first operation should have disappeared before the second is undertaken.

_Dressings._ A pad of sterilized wool, with a few layers of cyanide gauze moistened with 1-6,000 perchloride of mercury lotion next the closed eyelid, held in position by a bandage, is all that is necessary.

_Bandaging._ The bandage is started on the forehead over the affected eye and is carried in a direction away from the eye to be covered. A complete turn is made to encircle the head and is fixed with a pin. The bandage is then brought up beneath the ear and over the eye and fixed with pins on the forehead (Fig. 81). When absolute rest is desired, it is necessary to bandage both eyes. After intra-ocular operations this is desirable for the first three days. When pressure is desired, a figure-of-eight bandage should be used (Fig. 82). A useful bandage (Moorfield's bandage) for occlusion of both eyes is made from stockinette, which fits closely over the eyes and nose and is fastened with tapes.