PURPOSE: Glaucoma is the second cause, after cataract, of world blindness. Approximately half is thought to be primary angle-closure glaucoma (ACG). This review asks whether ACG can be prevented on a population basis. METHODS AND POPULATIONS: Review of published information from the Inuit of Greenland, Canada and Alaska, and descriptions of recent studies in Asian populations in Mongolia, China and South-East Asia. RESULTS: The Greenland Inuit have the shallowest anterior chamber depths (ACDs) so far recorded. The proportion of blindness due to ACG was reduced from 64% to 9% over 37 years by systematic optical measurement of central ACD and the van Herick test in the older Inuit, followed by gonioscopy and prophylactic iridectomy or laser iridotomy when indicated. In Mongolia, ultrasound measurement of central ACD had good sensitivity and specificity as a screening test. A randomized controlled trial of screening and prophylactic laser is being completed. In China and South-East Asia, the mechanism of angle closure appears to be more varied and complex and its detection may require more elaborate imaging. CONCLUSIONS: The mechanism of angle closure and potential for prevention by screening are likely to have to be determined specifically for each population at risk.
PURPOSE: To determine the prevalence of primary angle-closure glaucoma (PACG) in an isolated Greenlandic Inuit community and to examine the anatomical risk factors for this disease. METHODS: All individuals aged > or =40 years were examined. Visual acuity, refractive error, anterior chamber depth (ACD), intraocular pressure (IOP), gonioscopy, and optic disc characteristics were recorded. RESULTS: Seventy-nine individuals (65% response rate) were examined. Mean IOP was 12.0 mmHg. ACD was shallow and decreased with age and hypermetropia. ACD was deeper than observed in the same community in 1981 and another East Greenland population in 1970. Two subjects had definite PACG (2.5 %). CONCLUSION: This is the first study to use applanation tonometry in a Greenland population and confirms a low IOP as found in other populations of Inuit and Mongolians. ACD measured in 1998 was deeper than in 1981 in the same community which may represent a cohort effect indicating a secular change.