ABSTRACT
A study of the dependence of diaphragmatic properties of the iris on the degree of its atrophy carried out in 76 patients (78 eyes) with a pseudoexfoliative syndrome has shown that under the action of mezatone injected into the anterior chamber the maximum diameter of the pupil and the degree of its widening are in direct dependence on the degree of iris atrophy. The results obtained are of practical importance, allow to plan the course of cataract extraction and foresee complications. In iris atrophy of degree I, the maximum diameter of the pupil is sufficient to be that needed for cataract extraction made by a common method. In atrophy of degree II, it may become necessary during the operation to make sphincterotomy for a free withdrawal of the lens, and in atrophy of degree III, sphincterotomy should be planned, because maximum widening of the pupil in such patients is 3.88 +/- 0.16 only.