Materials and Methods: Detailed ophthalmological examinations, systemic diseases and blood groups of patients who applied to Balıkesir University Faculty of Medicine, Ophthalmology Outpatient Clinic between February 2019 and May 2020 with retinal vein occlusion were retrospectively analyzed. The blood groups of the patients were divided into 2 groups as O and non-O. The results were compared with a normal group matched in terms of age and gender. Regression analysis was performed to determine the relationship between blood group types and vein occlusions.

Results: A total of 78 people were included in the study. The mean age of 38 patients with vein occlusion was 61.8±11.3, while the mean age of 40 patients without vein occlusion was 64.0±10.3 (p=0.320). In the RVO patients group, 14 (36.8%) were female, 30 (78.9%) had non-O blood group, 20 (52.6%) had hypertension (HT), 19 (50%) had diabetes mellitus (DM). According to the results of logistic regression analysis, HT have statistically significant effect on RVO formation (OR 2.92 95% CI 1.14-7.51, p=0.025). The number of patients with non-O blood group was 30 (78.9%) in the RVO group and 25 (62.5%) patients in the control group had non-O blood group (p=0.140).

Conclusion: HT is the major risk factor for RVO. Although non-0 blood group is found at a higher rate in RVO patients, it does not show a significant difference. Keywords : ABO blood groups, Retinal vascular occlusion, Vein occlusion, Venous occlusion