[An epidemiological survey of primary angle-closure glaucoma (PACG) in Tibet].

The authors compared the results of a prevalence study of primary angle-closure glaucoma (PACG) in Duilong-Deqing county, suburb of Lhasa, Tibet in 1987, with those of a similar study in Shunyi county, suburb of Beijing in 1985. The prevalences of PACG in subjects over 20 years and over 40 years of age were 0.08% and 0.15% respectively in Tibet, significantly lower than the corresponding figures of 0.62% and 1.17% in Shunyi (P less than 0.001). The incidence of shallow anterior chamber in Tibet was much less than that in Beijing, in consistency with the low prevalence of PACG in Tibet. It was interesting to note that no acute attacks of PACG occurred after mydriasis with neosynephrine among Tibetians, while in Beijing, 6 cases of PACG occurred during mydriatic examination in subjects over 50 years of age.