Subchoroidal hæmorrhage. Of all the immediate complications which follow an intra-ocular operation this is by far the worst. The hæmorrhage is due to the giving way of a large choroidal vessel following the sudden reduction of tension, with the result that the choroid and retina are stripped up from the sclerotic, and, with the lens, may be partially extruded from the wound in the globe, from which the hæmorrhage then proceeds. It may occur whilst the patient is still on the operating table, or it may be discovered only after he has been put back to bed, the blood being seen coming through the dressings. Patients who have this condition complain of pain in the ‘corner of the eye’ at the time of the operation. The treatment consists in evisceration or enucleation. It is probable that limited extravasation of blood may also occur, which need not end in disintegration of the eye, but may cause vitreous opacity and defective vision for some weeks after the operation.
Remote. 1. The tension is not reduced by the iridectomy. In acute cases the prognosis with regard to the reduction of the tension and the improvement of vision is very satisfactory. The same cannot be said of chronic cases, especially those which have been operated on rather late in the disease. If iridectomy, which may be repeated downwards or extended from the previous coloboma, fail to reduce the tension, one or more of the following measures should be adopted:—
(a) The use of eserine.
(b) Sclerotomy.
(c) Cyclo-dialysis.
(d) Sclerectomy.
(e) Post-scleral puncture.
It is probably in this order that they should be tried.
2. Prolapse of the iris and irido-cyclitis should be treated as already indicated under cataract extraction (see [p. 208]).
3. The onset of glaucoma in the other eye may be induced by the dilatation of the pupil caused by bandaging, and is best avoided by the use of eserine. If it should occur, an iridectomy should be performed.