THE PURPOSE of any operation for glaucoma is the reduction of intraocular tension, and to accomplish this at least one of three results must be accomplished: (1) The normal intraocular pathway of drainage must be restored, (2) a new intraocular pathway opened or (3) a pathway formed for extraocular drainage. Many types of operations have been devised to accomplish these objectives. Of the first class, that is, operations devised to restore the normal pathway, iridectomy with its various modifications is the chief example. Cyclodialysis was thought by Heine, its originator, to accomplish the second objective, the opening of a new intraocular pathway; and, while experimental work on rabbit eyes which I did several years ago failed to confirm his claim, gonioscopic examinations have demonstrated an opening in the iris angle in successful cases, indicating a fistula of the suprachoroidal space. The operations which have been done to produce pathways of