Recent advances in the surgical treatment of glaucoma.

The modern concept of angle block, consequent very high intraocular pressure, consecutive iris ischaemia with sphincter failure, and inflammation resulting therefrom was almost completely unknown in the 1940S. Furthermore, Diamox and the osmotic agents were not available. The ophthalmologist was faced therefore with a painful inflamed eye with raging hypertension over which he had little control and the cause ofwhich was imperfectly known. The remedy was somewhat dangerous and time was pressing. The emergency broad iridectomy often through a hazardous Graefe section, the knife being threaded across the shallow anterior chamber the point dimly seen through a steamy cornea, was hurriedly performed, often late at night or on an exhausted patient and an often imperfectly anaesthetized eye. The first real advance during our period in the management of acute glaucoma was not, however, surgical but medical, the introduction of Diamox by Becker (I954). This drug and its successors, the parenteral and later oral osmotic agents, completely altered the surgical management of the disease. Iridectomy no longer had to be carried out while the pressure in the eye was raised, and time was available for a more leisurely and complete assessment of the situation. The chief object of such an assessment was to discover whether a fistulizing operation was required or whether an iridectomy would suffice. Three principal methods were available; tonography, gonioscopy, and later gonioscopy combined with Chandler's manoeuvre. Unfortunately the first of these, tonography, proved to be somewhat disappointing and has gradually been abandoned by most workers in the assessment of acute glaucoma. Gonioscopy also posed great difficulties in this type of case, first because of the state of the cornea and secondly because in all eyes with narrow angles it is notoriously difficult to be exactly certain whether an angle is just open or just shut. Chandler and Simmons (I965) attempted to get round this problem in an ingenious fashion. They advocated emptying the anterior chamber by a paracentesis and then immediately refilling it. The