The underlying theory of most modern operations for glaucoma is the creation of an artificial drainage channel from the anterior chamber to the loose subconjunctival tissues. The earlier operations, such as trephining and anterior sclerectomy, provide no means for keeping open the artificial channel through the sclera. Spontaneous closure of this channel by the natural healing processes is one of the two chief causes for failure in these operations. The other chief cause of failure is the improper preparation of the flap beneath which diffusion and absorption of the excessive aqueous is to occur. In the more recent operations, such as iridencleisis, iridotasis and other iris inclusion operations, an attempt is made to prevent healing and closure of the drainage canal by the interposition of iridic tissue, which also will act as a wick or seton. A serious objection to some of the operations of this type is the resultant