Prevalence of and risk factors for diabetic retinopathy: The Thessaloniki Eye Study.

OBJECTIVE

To estimate DR prevalence, risk factors, and undiagnosed disease in the Thessaloniki Eye Study.

DESIGN

Cross-sectional, population-based study.

SETTING

Community examinations and home visits in Thessaloniki, Greece.

PARTICIPANTS

Adults aged 60 years or older; 2468 with gradable fundus data or fundus examination were analysed.

EXPOSURES: Self-reported diabetes mellitus (DM), demographics, ocular/systemic history, and lifestyle factors.

MAIN OUTCOMES AND MEASURES: DR prevalence/severity graded from fundus photographs using a modified Airlie House system; clinically significant macular oedema (CSMO), vision-threatening retinopathy (VTR), and DR risk factors.

RESULTS

Among 2468 participants, DR prevalence was 6.9% (170/2468; 95% CI, 6.0%-8.0%). Among 352 participants with self-reported diabetes, 31.0% (109/352; 95% CI, 26.4%-36.0%) had DR; mild, moderate, severe non-proliferative DR, and proliferative DR were observed in 13.6%, 7.1%, 7.4%, and 2.8%, respectively. CSMO and VTR were present in 6.5% and 11.9%, respectively. Increased DR risk was associated with male gender (OR = 2.64), insulin therapy (OR = 4.87), and longer antihyperglycaemic treatment duration (OR = 1.05/year). Lower DR risk was associated with older age (OR = 0.87/year), regular alcohol intake (OR = 0.39), and migraines with aura (OR = 0.11). Among participants with DR, 73.9% were unaware of their diagnosis.

CONCLUSIONS

DR affected nearly one-third of participants with diabetes, and most DR cases were undiagnosed. These findings support improved DR screening and education in older Greek adults.