Retinal artery occlusion as an early indicator of macrovascular complications in diabetes

Background: A characteristic of the retinal circulation is that arterial occlusion is embolic or secondary to vasculitis but rarely or never due to in situ atherosclerosis. Therefore, retinal artery occlusion suggests the presence of cardiac or large-vessel disease outside the eye. This cohort study examined the general risk of macrovascular disease in individuals with diabetes, with or without retinal artery occlusion. Methods: We retrieved data on 992 subjects with incident retinal artery occlusion and preexisting diabetes, registered in Denmark between January 1, 2000, and December 31, 2018. Each retinal artery occlusion subject was matched for age, sex, and diabetes duration, with 5 control subjects with diabetes but without retinal artery occlusion. We performed survival analyses to compare the risk of extraocular macrovascular disease between the 2 groups in a 5-year follow-up. Results: After 1 year, the incidence of macrovascular disease in subjects with retinal artery occlusion was approximately 21 per 100 person-years (95% confidence interval [CI]: 18.11-24.29), compared to 6.25 per 100 patient-years (95% CI: 5.57-7.00) in those without retinal artery occlusion. After 5 years, the cumulative incidences of macrovascular disease were 51.2% (95% CI: 47.9-54.7%) and 29.4% (95% CI: 28.0-30.8%) in patients with diabetes with or without retinal artery occlusion, respectively. Hazard rate ratios were 3.36 (95% CI: 2.79-4.05) after 1 year and 2.27 (95% CI: 2.04-2.53) after 5 years. Conclusion: Among individuals with diabetes, those diagnosed with retinal artery occlusion had a higher general risk of macrovascular complications for at least 5 years after the occlusion event compared with those without retinal artery occlusion.