Prevalence of Retinopathy and Associated Factors in an Aged Cohort of Icelanders: the Age, Gene/Environment Susceptibility Reykjavik Study

Abstract

Purpose: : To describe the prevalence of retinopathy in Icelanders with and without diabetes mellitus (DM) and to determine association with risk factors in the DM group.

Methods: : From the population-based Age, Gene/Environment Susceptibility-Reykjavik study (AGES), 4992 participants, aged 67 and older are included. DM was defined as a fasting serum glucose of ≥ 7 mmol/L, a self-reported history of DM or use of diabetes medication. Retinopathy was assessed by grading two fundus photographs taken of each eye with a nonmydriatic camera after pupil dilatation. Associations between retinopathy and risk factors, in the DM group, were estimated by odds ratios from a multivariable logistic model adjusting for age, sex and statin use.

Results: : 596 persons (11.9%) were diagnosed as having DM, of whom retinopathy was found in 149 persons (25.2%, 95% CI 21.7-28.9). Retinopathy in the DM group, was associated with longer duration of diabetes (OR=1.5 per 10 yrs, 95% CI 1.2-1.7), insulin use (OR=6.1, 95% CI 2.9-12.7), use of oral anti-diabetic medication (OR=2.3, 95% CI 1.5-3.4), higher systolic blood pressure (OR=1.2 per 10 mm Hg, 95% CI 1.1-1.3), higher fasting blood glucose levels (OR=1.2 per mmol/L, 95% CI 1.1-1.3) and microalbuminuria (OR=1.9, 95% CI 1.2-2.9). Retinopathy was present in 464 persons without diabetes (10.7%, 95% CI 9.7-11.6).

Conclusions: : Among those with DM, the prevalence of retinopathy in AGES was similar to that among Caucasians in MESA (Multi-Ethnic Study of Atherosclerosis); associations with known risk factors were confirmed. Although the prevalence of retinopathy among diabetics is higher than among non-diabetics, the number of individuals with retinopathy is three-fold higher in the non-diabetic group.

Keywords: diabetic retinopathy • diabetes