Fig. 89. Capsulotomy. The method of dividing a dense band. This is done with two needles.
Results. These are good as a rule, but the operation may have to be performed again owing to an insufficient or non-central opening being obtained in the membrane, or to a fresh membrane forming; this is liable to take place if any irido-cyclitis follow the operation.
After-treatment. This should be carried out as described for needling.
EVACUATION
Indications. (i) In cases of increased tension associated with soft lens substance in the anterior chamber.
(ii) To accelerate the absorption of soft lens matter from the anterior chamber. As a rule it is only undertaken for the former condition.
Instruments. Speculum, fixation forceps, bent broad needle, curette.
Operation. Under cocaine.
First step. An incision is made behind the limbus, usually in an upper segment of the cornea, by means of a bent broad needle. The point of the instrument is passed into the anterior chamber immediately behind the limbus with the handle at right angles to the cornea; directly the anterior chamber has been entered the handle is depressed so that the point of the instrument shall turn forwards and avoid injuring the iris. The blade is passed on into the anterior chamber until the point reaches about the centre of the pupil. It is then either withdrawn directly, or, if a larger incision be desired, lateral pressure is made so that in withdrawing the blade the wound is enlarged.