Poor glycemic control impairs recovery from central retinal vein occlusion

Purpose To evaluate the association between suboptimal glycemic control and central macular thickness in central retinal vein occlusion patients over a 1-year follow-up period. Methods This retrospective cohort study included adult patients with central retinal vein occlusion diagnosed at the Helsinki University Hospital, Finland, with HbA1c levels measured within 6 months before or at diagnosis. Patients were divided into two groups: those with good (≤42 mmol/mol) and poor glycemic control (>42 mmol/mol). Central macular thickness and best-corrected visual acuity were assessed at baseline, 3 months, and 1 year. Results Among 40 patients, 10 had suboptimal glycemic control. At 3 months and 1 year, central macular thickness was significantly higher in the poor glycemic control group compared with the good glycemic control group (367.0 ± 43.3 µm vs. 288.2 ± 36.6 µm, p = 0.016 and 380.8 ± 44.8 µm vs. 302.0 ± 71.3 µm, p = 0.035, respectively). HbA1c levels correlated with central macular thickness at 3 months (R2 = 0.514, p = 0.045) but did not reach statistical significance at 1 year (R2 = 0.246, p = 0.071). Conclusions Poor glycemic control in patients with central retinal vein occlusion is associated with greater central macular thickness at both 3 months and 1 year. These findings emphasize the importance of optimal glycemic control to improve retinal outcomes in central retinal vein occlusion.