Long-term benefit of reduced intraocular pressure in primary open-angle glaucoma patients in Ethiopia.

Purpose: To determine the incidence of progression of primary open-angle glaucoma at individual levels of mean intraocular pressure (IOP) in patients in Ethiopia.

Methods: A retrospective, multicenter, cohort analysis of patient records with at least 5 years of potential follow-up were evaluated for risk factors associated with progressive optic disc and visual field loss.

Results: There were 300 patients with the potential of 5 years of follow-up. In total, 166 patients progressed before 5 years and 134 remained stable for the full 5-year follow-up period. Of the total sample, 84% of patients with IOPs < or =19 (n=117/139), 53% of patients with IOPs of 20 (n=9/17), 14% of patients with IOPs of 21-24 (n=9/63), and 0% of the patients with IOPs of > or =25 mmHg (n=0/79) remained stable over at least 5 years. The mean IOP was 17.4+/-2.1 in the stable group and 25.0+/-5.9 mmHg in the progressed group (p<0.0001). The highest average peak IOP was 24.5+/-4.5 in the stable group and 29.0+/-6.1 mmHg in the progressed group (p<0.0001). A multivariant regression analysis to determine risk factors for progression was positive for mean IOP (p=0.0097).

Conclusions: This study suggests that IOP reduction in a developing country, despite potential limitations in diagnostic techniques, follow-up, and compliance, can be effective in reducing the risk of glaucomatous progression over long-term follow-up.