Cataract epidemiology performed with Scheimpflug documentation.

Cataract epidemiological surveys applying a photodocumentation system were performed by the author's group in three climatically different sites with racially different populations: Noto (Japan), Reykjavik (Iceland) and Singapore. Data regarding age- and sex-related changes in lens transparency decrease, prevalence and type of opacification are specific for the three populations studied. Direct comparisons of the three different populations revealed that the age-related prevalence of lens opacification, including whole grades, in the Japanese and Icelandic populations was almost the same, whereas that of the Singaporeans was significantly higher. However, the percentage of progressed cases was highest among Singaporeans, followed by the Japanese and Icelanders. Although the application of photodocumentation for cataract epidemiological studies has been limited up to now mainly because of high cost and sophisticated and time-consuming examination methods, more accurate, reliable and objective data can be obtained which will allow prospective decisions on the incidence of cataract.