Glaucoma in Mongolia. A population-based survey in Hövsgöl province, northern Mongolia.

OBJECTIVES

To determine the prevalence of glaucoma and suspect glaucoma, and to classify the cases detected according to mechanism.

DESIGN

A population-based prevalence study.

SETTING

Rural and urban locations in Hövsgöl province, northern Mongolia.

PARTICIPANTS

Nine hundred forty-two (94.2%) of 1000 individuals 40 years of age and older were examined.

MAIN OUTCOME MEASURE

Primary angle-closure glaucoma was diagnosed in subjects with previous acute or intermittent symptoms of angle closure and in individuals with an occludable angle and an intraocular pressure greater than 19 mm Hg or a glaucomatous visual field.

RESULTS

The prevalence of manifest primary angle-closure glaucoma was 1.4% (14 subjects). The prevalence of gonioscopically occludable angles was 6.4% (64 subjects, including those with glaucoma). Primary open-angle glaucoma was diagnosed in 5 subjects (prevalence, 0.5%). As all these subjects were older than 60 years, the prevalence became 2.1% for this age group. Three cases (prevalence, 0.3%) of secondary open-angle glaucoma were detected. No cases of secondary angle-closure glaucoma were 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 in northern Mongolia. Primary angle-closure glaucoma is more prevalent than primary open-angle glaucoma, supporting clinic-based data from other east Asian countries. Among the subjects examined, 97 (9.7%) had either manifest, latent, or suspect glaucoma. Neighboring populations may be similarly affected owing to a shared genetic heritage.