[Surgical therapy of glaucoma].
During recent years, glaucoma surgery has been modified by the introduction of new antiglaucoma drugs and by laser therapy. Various glaucoma operations have, however, retained their value in the treatment of severe glaucoma cases. Acute angle-closure glaucoma is best treated by iridectomy. When a clear cornea is present, laser iridectomy can be performed. Prophylactic treatment of the contralateral eye is mandatory. In chronic open-angle glaucoma, filtration surgery with a scleral flap is usually performed (goniotrephination or trabeculectomy). Modifications in the conjunctival incision and the use of antifibroblastic drugs may reduce the failure rate for difficult cases in the future. Individual adjustment of postoperative treatment is of great importance for the development of functioning filtering blebs. Reoperations retain their high incidence of subconjunctival scarring. In congenital glaucoma, the success rate of trabeculotomy equals the success rate of goniotomy. Trabeculotomy has advantages when the cornea is cloudy, but may be more difficult to perform in eyes with a stretched anterior segment or in secondary congenital glaucomas. In neovascular glaucoma, cryotherapy of the peripheral retina often normalizes the intraocular pressure by reduction of neovascularization. Cyclocryotherapy of the anterior pars plicata often results in cataract and phthisis bulbi and is only rarely used. In non-neovascular secondary glaucoma or numerous reoperations for primary glaucoma, the implantation of a Molteno or Schocket implant may be helpful. Cyclodialysis is seldom used because its outcome is extremely variable. It is mostly replaced by modified filtering surgery, including ciliary tendon disinsertion (Watson trabeculectomy). If the IOP is high in coexisting glaucoma and cataract, two separate procedures are normally performed successively: when the filtering surgery has been successfully performed and settled, a separate extracapsular cataract operation is performed via a clear corneal incision. Simultaneous procedures, if necessary, can be performed with a trabeculotomy or with a filtering operation. If the IOP is borderline, an extracapsular cataract operation is normally sufficient to lower the IOP for some mmHg. Cataract formation after filtering surgery has become a less severe complication, as posterior chamber lens implantation is also possible in glaucomatous eyes. Therefore, filtering surgery nowadays seems indicated at earlier stages of glaucoma.