The idea of acting on the ciliary body to reduce the aqueous output and consequently to lower the intraocular tension is not a recent therapeutic advance. From the cyclotomy of Hancock1and Abadie,2the sclerocyclotomy with thermocautery of Fiore3and the cyclectomy of Verhoeff4developed. Other clinical or experimental attempts to reduce eye tension by means of cauterizations of the pericorneal or ciliary region were performed by Hamburger5(silver nitrate cauterizations), by L. Weekers,6by Puscariu and Cerkez,7by Favaloro8(following the technic of Schoeler9), by Preziosi10and by Curran.11The two latter aimed also at a good filtration by perforating the sclera with galvanocautery. All these procedures had, however, only a restricted number of followers because of the fear that excessive damage to the ciliary body might arise. A new epoch in this field was opened by the