Incidence of Acute Primary Angle-closure Glaucoma in Singapore: An Island-Wide Survey

Abstract

OBJECTIVES: To determine the incidence of acute primary angle-closure glaucoma (APACG) in Singapore and to identify demographic and meteorological risk factors. DESIGN: A prospective, island-wide incidence study. SETTING: All government and private ophthalmological practices in Singapore, from March 1, 1995, to February 29, 1996. METHODS: New cases of APACG were identified by all ophthalmologists in Singapore during a 1-year period. Demographic and clinical details were recorded. RESULTS: One hundred eighty-nine people (208 eyes) were seen with APACG for the first time during the 1-year period. These new cases represent an incidence of 12.2 per 100,000 per year (95% confidence interval, 10.5-13.9) in those aged 30 years and older. Major risk factors identified were female sex (relative risk, 2.4), Chinese ethnic origin (relative risk, 2.8), and age of 60 years or older (relative risk, 9.1). Half of those affected were seen 3 days or more after the onset of symptoms. Attacks were more frequent on hotter days. There also was a relationship between the number of attacks per day and the mean number of sunspots and mean solar radio flux during the previous 30 days. CONCLUSIONS: There is a high incidence of APACG in Singapore, with elderly women being the highest risk group. Chinese Singaporeans are at higher risk than other ethnic groups (Malay and Indian). There is often a substantial delay before these patients consult a physician. The onset of APACG seems to be associated with meteorological factors.