Comparison of glaucomatous progression between untreated patients with normal-tension glaucoma and patients with therapeutically reduced intraocular pressures

PURPOSE: To determine if intraocular pressure plays a part in the pathogenic process of normal-tension glaucoma. METHODS: One eye of each eligible subject was randomized either to be untreated as a control or to have intraocular pressure lowered by 30% from baseline. Eyes were randomized if they met criteria for diagnosis of normal-tension glaucoma and showed documented progression or high-risk field defects that threatened fixation or the appearance of a new disk hemorrhage. The clinical course (visual field and optic disk) of the group with lowered intraocular pressure was compared with the clinical course when intraocular pressure remained at its spontaneous untreated level. RESULTS: One hundred-forty eyes of 140 patients were used in this study. Sixty-one were in the treatment group, and 79 were untreated controls. Twenty-eight (35%) of the control eyes and 7 (12%) of the treated eyes reached end points (specifically defined criteria of glaucomatous optic disk progression or visual field loss). An overall survival analysis showed a statistically significant difference between the two groups ( P < .0001). The mean survival time ±SD of the treated group was 2,688 ± 123 days and for the control group, 1,695 ± 143 days. Of 34 cataracts developed during the study, 11 (14%) occurred in the control group and 23 (38%) in the treated group ( P = .0075), with the highest incidence in those whose treatment included filtration surgery. CONCLUSIONS: Intraocular pressure is part of the pathogenic process in normal-tension glaucoma. Therapy that is effective in lowering intraocular pressure and free of adverse effects would be expected to be beneficial in patients who are at risk of disease progression

The effectiveness of intraocular pressure reduction in the treatment of normal-tension glaucoma

PURPOSE: In a companion paper, we determined that intraocular pressure is part of the pathogenesis of normal-tension glaucoma 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 glaucoma was randomized either to no treatment (control) or to a 30% intraocular pressure reduction from baseline. To be eligible for randomization, the normal-tension glaucoma eyes had to show documented progression of field defects or a new disk hemorrhage 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 patients during the course of follow-up from the initial baseline at randomization. In a separate analysis, data of patients developing cataracts were censored at the time that cataract 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 cataract affected visual acuity, visual field progression 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 cataract in the group that underwent filtration surgery. CONCLUSIONS: The favorable effect of intraocular pressure reduction on progression of visual change in normal-tension glaucoma was only found when the impact of cataracts on visual field progression, produced largely by surgery, was removed. Lowering intraocular pressure without producing cataracts is beneficial. Because not all untreated patients progressed, the natural history of normal-tension glaucoma must be considered before embarking on intraocular pressure reduction with therapy apt to exacerbate cataract formation unless normal-tension glaucoma threatens serious visual loss

The Effects of Beta-Blockers on Ocular Blood Flow in Patients with Primary Open Angle Glaucoma: A Color Doppler Imaging Study

PURPOSE. TO evaluate the effects of four commonly used beta-blockers on ocular blood flow in patients with primary open angle glaucoma (POAG)