Cataract extraction rates among Chinese, Malays, and Indians in Singapore - A population-based analysis

Objective: To describe the rates of cataract extraction among Chinese, Mala ys, and Indians in an urban population in Asia. Design: Population-based incidence study using data from a medical savings fund. Study Population: Chinese, Malay, and Indian residents in Singapore. Methods: Data on all cataract operations performed for "senile cataract" (I nternational Classfication of Diseases, Ninth Revision, Clinical Modificati on code 366.1) between 1991 and 1996 were retrieved from Medisave, a popula tion-wide, government-administered medical savings fund. The Singapore cens us was used as a denominator to allow an estimation of age, sex, and race-s pecific annual rates of cataract surgery. Results: Between 1991 and 1996, 61 210 cataract operations for "senile cata ract" were performed on Singapore residents, which is equivalent to an aver age rate of 356.4 cataract operations per 100 000 persons per year (95% con fidence interval [CI], 353.6-359.2). The average rate was highest for India ns (age-sex adjusted rate of 396.5 per 100 000/year), followed by Chinese ( 371.2 per 100 000/year), and lowest for Malays (237.2 per 100 000/year). Wo men had higher rates of cataract extraction than men (age-adjusted relative risk, 1.14; 95% CI, 1.11-1.17), with this pattern consistent across the 3 racial groups. The rate of cataract extraction increased by an average of 4 0 operations per 100 000/year (95% CI, 28.6-52.8) between 1991 and 1996. Ov erall, the proportion of cataract extraction without concurrent intraocular lens implantation was low (n = 762, 1.2%), but rates still decreased by an average of 0.8 per 100 000 per year (95% CI, 0.03-1.5) during the 6 years. Conclusions: The rate of cataract extraction in Singapore is consistent wit h rates seen in developed countries in the West. Racial variation in rates suggests varying predisposition to cataract development and/or threshold fo r cataract surgery between Chinese, Malay, and Indian populations in Singap ore.