An operation to treat glaucoma, where part of the iris is used as a drainage channel through a hole in the conjunctiva.
An operation for glaucoma in which a small incision is made into the eye, beneath the conjunctiva and close to the cornea, and part of the iris is drawn into it. The iris acts like a wick and keeps the incision open for the drainage of fluid from the front chamber of the eye to the tissue beneath the conjunctiva.
An operation for relieving increased intraocular pressure, as in glaucoma, in which the iris and a portion of the limbus are excised to allow increased volume of the aqueous humor under the conjunctiva.