GLAUCOMA IN MONGOLIA - A POPULATION-BASED SURVEY IN HOVSGOL PROVINCE,NORTHERN MONGOLIA

Objectives: To determine the prevalence of glaucoma and suspect glauco ma, and to classify the cases detected according to mechanism. Design: A population-based prevalence study. Setting: Rural and urban locatio ns in Hovsgol province, northern Mongolia. Participants: Nine hundred forty-two (94.2%) of 1000 individuals 40 years of age and older were e xamined. Main Outcome Measure: Primary angle-closure glaucoma was diag nosed in subjects with previous acute or intermittent symptoms of angl e closure and in individuals with an occludable angle and an intraocul ar pressure greater than 19 mm Hg or a glaucomatous visual field. Resu lts: The prevalence of manifest primary angle-closure glaucoma was 1.4 % (14 subjects). The prevalence of gonioscopically occludable angles w as 6.4% (64 subjects, including those with glaucoma). Primary open-ang le glaucoma was diagnosed in 5 subjects (prevalence, 0.5%). As all the se subjects were older than 60 years, the prevalence became 2.1% for t his age group. Three cases (prevalence, 0.3%) of secondary open-angle glaucoma were detected. No cases of secondary angle-closure glaucoma w ere diagnosed. The prevalence of blindness was 1.2% (12 subjects), and primary glaucoma accounted for one third of these cases (4 subjects). Conclusions: We confirmed glaucoma as a major public health problem i n northern Mongolia. Primary angle-closure glaucoma is more prevalent than primary open-angle glaucoma, supporting clinic-based data from ot her east Asian countries. Among the subjects examined, 97 (9.7%) had e ither manifest, latent, or suspect glaucoma. Neighboring populations m ay be similarly affected owing to a shared genetic heritage.