Surgical decision in glaucoma simplex.

The indications for 220 trabeculectomies performed by six surgeons at three different centres were studied. 82% of the decisions to operate were based on a non-progressive but high risk situation. The 18% of cases showing preoperative deterioration were characterised by early presentation and low preoperative residual pressures. There was a distinct similarity in the incidence of individual indications at the different centres.