Cumulative Incidence of Patients with Disc Hemorrhages in Glaucoma and the Effect of Therapy

Purpose: In this longitudinal study, the cumulative incidence of patients with glaucoma and disc hemorrhages was investigated. A possible effect of glaucoma therapy on the incidence rate of disc hemorrhages was evaluated. Methods: A group consisting of 68 patients with primary open-angle glaucoma (POAG), 34 with normal-pressure glaucoma, and 125 with suspected glaucoma (mean follow-up, 7.3 ± 2.5 years; range 3–13 years) was observed closely with quarterly examinations. Results: In normal-pressure glaucoma, the cumulative incidence of patients with disc hemorrhages was 35.3%, which was significantly higher than for those with POAG (10.3%; P < 0.01) and for those with suspected glaucoma (10.4%; P < 0.001). The mean follow-up period before a first disc hemorrhage was detected was 2.5 ± 2.8 years. In the bleeders, recurrent disc hemorrhages were observed in 67% of the patients with normal-pressure glaucoma, 29% of those with POAG, and 54% of glaucoma suspects. In normal-pressure glaucoma, therapy had no effect on the incidence rate of disc hemorrhages. In glaucoma suspects, a significant reduction of the incidence rate of disc hemorrhages per year (0.11 ± 0.04) was observed during episodes with therapy compared with episodes without (0.43 ± 0.15; P < 0.05). A concept of two populations (i.e., one with disc hemorrhages and the other never having them) seems to be valid for normal-pressure glaucoma, but not for POAG and suspected glaucoma. Conclusion: The cumulative incidence of initial disc hemorrhages increases with time in POAG and suspected glaucoma, but reaches a limit in normal-pressure glaucoma. Glaucoma therapy may reduce the incidence rate of all, initial and recurrent, disc hemorrhages in patients with high pressures, but not in patients with normal-pressure glaucoma.