Risk of retinal vein occlusion in patients with diabetes mellitus: A retrospective cohort study.

Aims: To investigate the risk of retinal vein occlusion (RVO) in new-onset diabetes mellitus (DM) patients.

Methods: This nationwide, retrospective, matched cohort study included 240,761 DM patients registered between January 2003 and December 2005 in the Longitudinal Cohort of Diabetes Patients database. An age- and sex-matched control group comprising 240,761 non-DM patients (case: control = 1:1) was selected from the Taiwan Longitudinal Health Insurance Database 2000. Information for each patient from the index date until December 2013 was collected. The incidence and risk of RVO were compared between the two groups. Cox proportional hazard regression analysis was performed to calculate the adjusted hazard ratio (HR) for RVO after adjustment for potential confounders. The RVO cumulative incidence rate was obtained using Kaplan-Meier analysis.

Results: During the follow-up period, 1,456 DM patients developed RVO (491, central retinal vein occlusion; 965, branch retinal vein occlusion). There was a significantly elevated risk of RVO in DM patients compared with the controls (incidence rate ratio = 1.91, 95% confidence interval [CI] = 1.75-2.08). Patients with DM showed significant risk of RVO after adjustment for potential confounders (hypertension, hyperlipidemia, congestive heart failure, coronary artery disease, and chronic renal disease) in the full cohort (adjusted HR = 1.76, 95% CI = 1.61-1.93). Additionally, patients with hypertension had a significantly higher risk of RVO than patients without hypertension after adjustment for other confounders in the cohort (adjusted HR = 1.50, 95% CI = 1.36-1.65).

Conclusions: We found that patients with DM have increased risks of RVO. In addition to blood pressure control, we recommend educating patients with DM about RVO, to prevent its subsequent occurrence.