Objective To determine the longitudinal trends in the probability of blindness due to open-angle glaucoma (OAG) in Olmsted County, Minnesota, from 1965 to 2009. Design Retrospective, population-based cohort study. Participants All residents of Olmsted County, Minnesota (aged ≥40 years) who were diagnosed with OAG between January 1, 1965, and December 31, 2000. Methods All available medical records of every incident case of OAG were reviewed until December 31, 2009, to identify progression to blindness, defined as visual acuity ≤20/200 or visual field constriction to ≤20. Kaplan-Meier analysis was used to estimate the cumulative probability of glaucoma-related blindness. Population incidence of blindness within 10 years of diagnosis was calculated using US Census data. Rates for subjects diagnosed in the period 1965-1980 were compared with rates for subjects diagnosed in the period 1981-2000 using log-rank tests and Poisson regression models. Main Outcome Measures Cumulative probability of OAG-related blindness and population incidence of blindness within 10 years of diagnosis. Results Probability of glaucoma-related blindness in at least 1 eye at 20 years decreased from 25.8% (95% confidence interval [CI], 18.5-32.5) for subjects diagnosed in 1965-1980 to 13.5% (95% CI, 8.8-17.9) for subjects diagnosed in 1981-2000 (P = 0.01). The population incidence of blindness within 10 years of the diagnosis decreased from 8.7 per 100 000 (95% CI, 5.9-11.5) for subjects diagnosed in 1965-1980 to 5.5 per 100 000 (95% CI, 3.9-7.2) for subjects diagnosed in 1981-2000 (P = 0.02). Higher age at diagnosis was associated with increased risk of progression to blindness (P < 0.001). Conclusions The 20-year probability and the population incidence of blindness due to OAG in at least 1 eye have decreased over a 45-year period from 1965 to 2009. However, a significant proportion of patients still progress to blindness despite recent diagnostic and therapeutic advancements.
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