Risk factors for cataract: a case study at National University of Malaysia Hospital

The purpose of this study was to identify the most common forms of age-related cataracts and to estimate possible risk factors for age-related cataracts in a sample of cataract patients at the National University of Malaysia Hospital. Thirty five patients (17 males and 18 female) with cataracts were recruited from the ophthalmology ward and clinic at the hospital. The age range of the patients was between 39 to 93 years (mean 64.9 11.5 years). The Lens Opacities Classification System (Locs) III was used to grade nuclear, cortical and posterior subcapsular lens opacities. Grading of the cataract was carried out and the following information was collected: initial visual acuity and best-corrected visual acuity, demographic details, health history, dietary intake of antioxidants and lifetime ocular ultraviolet B exposure. Analyses were conducted using a standard case-control design. T-tests were used to assess the significance of continuous variables and chi-squared tests were used for categorical variables. The overall prevalence of cortical cataract was 34.4% (12 patients), nuclear cataract was 60.0% (21 patients), and posterior subcapsular cataract was 57.1% (20 patients). No significant potential risk factor was found for nuclear cataracts. In the case of posterior subcapsular cataract, hypertension was the only potential significant risk factor (x2 = 4.38, p = 0.036), and in the case of cortical cataract, cigarette smoking was the only significant risk factor. Although lifetime effective ocular UV-B exposure was found to be not a significant potential risk factor, but it was seen that for cortical cataracts, the mean difference of lifetime effective ocular UV-B exposure between those with cortical and those without cortical cataracts was larger compared to others with nuclear and posterior subcapsular cataracts. Hypertension was found to be a potential significant risk factor for posterior subcapsular cataract whereas cigarette smoking was a potentially significant risk factor for cortical cataract. Although not statistically significant, lifetime effective ocular UV-B exposure maybe a potential risk factor for cortical cataract