EFFECT OF TRABECULOTOMY IN NORMAL EYES OF RHESUS AND CYNOMOLGUS MONKEYS STUDIED BY ANTERIOR CHAMBER PERFUSION

Trabeculotomy ab externo was performed in 5 rhesus and 18 cynomolgus monkeys. Prae- and postoperative (2 weeks and later) anterior chamber perfusions were made to estimate intraocular pressure and outflow facility. The operation caused little or no consistent changes in intraocular pressure measured in the anesthetized monkey. In rhesus monkeys facility increased, in cynomolgus monkeys it decreased on an average. A mathematical analysis of the perfusion data was made under the assumption that the operation had produced a hole in the trabecular meshwork but that simultaneously parts of the filter had been clogged. The part of the scleral wall of the canal perfused from the hole was estimated to be of the order of 10 to 30° while in some cases the capacity for filtration was greatly reduced over much of the remaining meshwork. The combined effect of these opposite changes can be a slight increase in facility or a decrease, depending on the prae-operative state of the meshwork. If resistance is high to begin with, as in glaucoma, the operation may normalize overall outflow facility. The present paper shows that by an almost superhuman effort it is still just barely possible to write about matters of glaucoma without quoting our admired and beloved friend and teacher Goldmann. © 1969 Dr. W. Junk N.V.