The incidence of primary angle-closure glaucoma in Olmsted County, Minnesota

Objectives: To determine the incidence of primary angle-closure glaucoma (PACG) and to assess the visual outcomes of patients treated for PACG. Design: Population-based retrospective incidence study. Setting and Patients: Residents of Olmsted County, Minnesota, aged 40 years and older and diagnosed with PACG in the 13-year period between January 1, 1980, and December 31, 1992. Main Outcome Measure: Incident cases of PACG identified through the Medical Diagnostic Index of Mayo Clinic, Rochester, Minn, and the Rochester Epidemiology Project. Results: Thirty-six incident cases were identified. The mean annual age- and sex-adjusted incidence per 100 000 people aged 40 years and older was 8.3 (95% confidence interval, 5.6-11.0). The probability of monocular blindness associated with PACG at the time of diagnosis was 14%. Among patients not monocularly blind at diagnosis, the 5-year probability of developing monocular blindness associated with PACG was 4%. Conclusions: Primary angle-closure glaucoma is an uncommon disease in our community. Most of the patients blinded by PACG were blind at the time the condition was diagnosed.