[Goniotrepanation using scleral flap in modern surgery of glaucoma]

Abstract

In the introduction, the principles and limitations of modern glaucoma surgery are described. There then follow some personal observations on the history of goniotrepanation, from which it is evident that the scleral flap is not the invention of any single surgeon, but rather the result of experiments by several. The importance of the scleral flap was proved by the almost simultaneous appearance of trabeculectomy and goniotrepanation and, some time later, of Schleie's covered fistulizing operation. The technical details of goniotrepanation and the features peculiar to this procedure are then described. It follows from this description that goniotrepanation is a microsurgical procedure demanding skill and experience on the part of the surgeon. Comparative studies of goniotrepanation in the literature are then discussed in detail. These are concerned with postoperative findings, pressure regulation, morphological changes at the site of the operation and the effect on visual function. The advantages of goniotrepanation and the function of the parathalamus, which represents a new drainage path for the aqueous, are then described. The procedure creates a normal balance between the quantity of aqueous produced and its drainage to the exterior, resulting in a normalization of intraocular pressure. This drain does not lead directly to the subconjunctival space, but indirectly, via normal pathways, through the parathalamus formed by the flap. The creation of the parathalamus can be useful in glaucoma surgery; it offers advantages as regards both indication and surgical technique.