Population-based study on prevalence and risk factors of age-related cataracts in Peitou, Taiwan

Age-related cataracts are the main cause of blindness throughout the world. Nonetheless, population-based data on the epidemiology of age-related cataracts among Taiwanese populations are not readily available. This study was conducted to estimate the prevalence of age-related cataracts and to determine the relationships of age, gender, blood pressure, diabetes and smoking to the risks of age-related cataracts in an urban Taiwanese population.

The study was part of a population-based survey of eye diseases among residents aged 50 years or older in Peitou Precinct, Taipei, Taiwan. Of the 2,700 eligible persons, 2,038 (75.5%) underwent a standard evaluation protocol including dilated slit-lamp examination, a questionnaire of medical and ophthalmic histories and blood pressure measurement.

Among the participants, 1,040 were diagnosed with age-related cataracts. The prevalence was 51.0% (95% confidence interval, 48.9%-53.2%). Nuclear opacity was the most prevalent type (718/1,040; 35.2%) of cataracts, followed by posterior subcapsular opacity (311/1,040; 15.3%) and cortical opacity (163/1,040; 7.8%). An increased risk of age-related cataracts was associated with female gender (p = 0.002). When a single type of lens opacity was considered, diabetes was significantly associated with a posterior subcapsular cataract (p = 0.022). Overall, older women with diabetes and relatively lower diastolic blood pressure were more likely to have age-related cataracts.

The study provided the first prevalence data on age-related cataracts in an urban Taiwanese population and highlighted the relationships of age, gender, blood pressure and diabetes to the frequency and type of age-related cataracts. The results can assist in the design and implementation of intervention programs to reduce the prevalence of age-related cataracts.