Baseline characteristics and risk factors of retinal vein occlusion: a study by the Korean RVO Study Group.

We investigated the demographic characteristics and risk factors of Korean patients with naÏve central or branch retinal vein occlusion (CRVO or BRVO). This study enrolled 41 clinical sites throughout Korea and included 557 consecutive patients with retinal vein occlusion (RVO) from May through November 2010. A total of 557 patients with new-onset RVO participated in this study. Two hundred and three (36.4%) patients were diagnosed with CRVO and 354 (63.6%) patients were diagnosed with BRVO. Comparisons between the two groups showed that the prevalence of diabetes mellitus was significantly higher in CRVO patients and hypertension was significantly higher in BRVO patients (P = 0.001 and 0.002, respectively). Poor baseline visual acuity was significantly associated with female and old age in BRVO patients (P = 0.002 and 0.013, respectively), whereas the wide intraretinal hemorrhage (CRVO, P = 0.029; BRVO, P < 0.001) and the macular ischemia (CRVO, P < 0.001; BRVO, P < 0.001) were associated with both groups. The study results show the clinical features of RVO in Korean patients. Hypertension is strongly associated with BRVO and diabetes mellitus is more strongly associated with CRVO in Korean patients with RVO. As the first nationwide study performed by the Korean Retinal Society, the results of this study can be applied to future studies on RVO.