The effectiveness of intraocular pressure reduction in the treatment of normal-tension @entity726 . Collaborative Normal-Tension XXXX Study Group.

@entity1 @entity227 @entity231 @entity548 @entity726 @entity2790
PURPOSE: In a companion paper, we determined that intraocular pressure is part of the pathogenesis of normal-tension @entity726 by analyzing the effect of a 30% intraocular pressure reduction on the subsequent course of the disease. We report an intent-to-treat analysis of the study data to determine the effectiveness of pressure reduction. METHODS: One eligible eye of 145 subjects with normal-tension @entity726 was randomized either to no treatment (control) or to a 30% intraocular pressure reduction from baseline. To be eligible for randomization, the normal-tension @entity726 eyes had to show documented progression of field defects or a new disk @entity548 or had to have field defects that threatened fixation when first presented for the study. Survival analysis compared time to progression of all randomly assigned @entity1 during the course of follow-up from the initial baseline at randomization. In a separate analysis, data of @entity1 developing @entity231 were censored at the time that @entity231 produced 2 lines of Snellen visual acuity loss. RESULTS: Visual field progression occurred at indistinguishable rates in the pressure-lowered (22/66) and the untreated control (31/79) arms of the study (P = .21). In an analysis with data censored when @entity231 affected visual acuity, @entity227 was significantly more common in the untreated group (21/79) compared with the treated group (8/66). An overall survival analysis showed a survival of 80% in the treated arm and of 60% in the control arm at 3 years, and 80% in the treated arm and 40% in the controls at 5 years. The Kaplan-Meier curves were significantly different (P = .0018). The analyses gave different results because of a higher incidence of @entity231 in the group that underwent filtration surgery. CONCLUSIONS: The favorable effect of intraocular pressure reduction on progression of visual change in normal-tension @entity726 was only found when the impact of @entity231 on @entity227 , produced largely by surgery, was removed. @entity2790 without producing @entity231 is beneficial. Because not all untreated @entity1 progressed, the natural history of normal-tension @entity726 must be considered before embarking on intraocular pressure reduction with therapy apt to exacerbate @entity231 formation unless normal-tension @entity726 threatens serious @entity227 .
