Abstract
Purpose: :
To determine the association of refractive errors and axial ocular dimensions and prevalent age-related cataract in the Malay population in Singapore.
Methods: :
A population-based cross-sectional study which examined 3,280 (78.7% response) adults of Malay ethnicity aged 40 to 80 years. Refractive error was determined by subjective refraction and if not obtainable, by autorefraction. Biometry was performed using the Zeiss IOL-Master. Other risk factor data were collected using an interviewer-administered questionnaire. Digital slit lamp and retroillumination lens photographs were taken and graded for age-related nuclear, cortical and posterior subcapsular (PSC) cataract following the Wisconsin system.
Results: :
Excluding those with prior cataract surgery, 2806 (85.5%) participants with gradable lens photographs and biometry data of the right eye were analyzed. After adjusting for possible confounders of age, gender, body mass index, systolic blood pressure, HbA1c, current smoking status, education and height, mild to moderate myopia (spherical equivalent -0.5 to -5.0 diopters) was associated with increased prevalence of nuclear cataract (odds ratio, OR, 5.3, 95% confidence interval, CI: 3.5, 8.0), while high myopia (spherical equivalent <-5.0 diopters) was associated with both increased prevalence of nuclear (OR 4.8, 95% CI: 2.1, 11.2) and PSC cataract (OR 2.5, 95% CI: 1.3, 5.1). Eyes with longer axial length were associated with prevalent nuclear and cortical cataract (p trend 0.035 and 0.001 respectively).
Conclusions: :
This study confirms the link between myopia and nuclear cataract, with high myopia also associated with PSC cataract. Longer axial length, but not spherical equivalent refraction, was associated with cortical cataract.
Keywords: cataract • refraction • myopia