A System of Operative Surgery Part 37

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

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

(iv) To examine the aqueous for organisms in cases of cyc.l.i.tis 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 (Samisch'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needle, attached to a hypodermic syringe, should be pa.s.sed into the anterior chamber at the limbus and the fluid withdrawn into the syringe by an a.s.sistant (Fig. 123). The spot through which the needle is pa.s.sed 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 ma.s.s 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 pa.s.sed 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 The needle is then withdrawn and is usually followed by a rush of aqueous.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 In some cases where a very tenacious hypopyon is present it may be withdrawn with the iris forceps.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.

[Ill.u.s.tration: FIG. 123. HOLLOW NEEDLE USED FOR PARACENTESIS OF THE ANTERIOR CHAMBER. This is used when it is desired to examine the aqueous bacteriologically. Care should be taken to see that the cutting blade is sufficiently wide to take the shaft of the needle.]

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-cyc.l.i.tis with kerat.i.tis 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 pa.s.sed through the superficial episcleral tissue. Unless the wound be small the prognosis is not good, as it is liable to be followed by irido-cyc.l.i.tis, 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--a.s.sisted 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 gla.s.s. 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 gla.s.s 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 pa.s.s right through the globe and be embedded in the orbit.

[Ill.u.s.tration: FIG. 124. AUTHOR'S CHAIR FOR THE LOCALIZATION OF FOREIGN BODIES IN THE EYE BY THE X-RAYS. A is a rifle sight for centring the anode, C, on the cross wire, B, behind which the photographic plate is subsequently placed. P is the screw clamping the head-piece on to the patient's head. Q is the screw for regulating the height of the tube and the distance from the patient. R is the screw for regulating the height of the head-piece. The inset shows the arm carrying the tube more highly magnified. E is the sliding arm carrying the tube for lateral displacement marked for stereoscopic photographs. F is the pointer for marking the position of the anode. D is the screw for clamping when in position.]

=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 gla.s.s, 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 gla.s.s 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-cyc.l.i.tis with kerat.i.tis 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 circ.u.mstances 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.

[Ill.u.s.tration: FIG. 125. SMALL ELECTRO-MAGNET FOR EXTRACTING PIECES OF STEEL FROM THE EYE. It is made to work direct off the electric main.]

=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-cyc.l.i.tis; if this be prolonged, and kerat.i.tis 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.