Objective: This study aimed to determine the probability of a patient developing legal blindness in either one or both eyes from newly diagnosed and treated open-angle glaucoma (OAG) after starting medical or surgical therapy or both.
Design: The study design was a retrospective, community-based descriptive study.
Participants: Two hundred ninety-five residents of Olmsted County, Minnesota, newly diagnosed with, and treated for, OAG between 1965 and 1980 with a mean follow-up of 15 years (standard deviation +/- 8 years) participated.
Intervention: Kaplan-Meier cumulative probability of blindness was estimated for patients treated and followed for OAG.
Main outcome measures: Legal blindness, defined as a corrected visual acuity of 20/200 or worse, and/or visual field constricted to 20 degrees or less in its widest diameter with the Goldmann 1114e test object or its equivalent on automated perimetry, secondary to glaucomatous loss, was measured.
Results: At 20-years' follow-up, the Kaplan-Meier cumulative probability of glaucoma-related blindness in at least one eye was estimated to be 27% (95% confidence interval, 20%-33%), and for both eyes, it was estimated to be 9% (95% confidence interval, 5%-14%). At the time of diagnosis, 15 patients were blind in at least 1 eye from OAG.
Conclusion: A retrospective study of a white population determined that the risk of blindness from newly diagnosed and treated OAG may be considerable.