ObjectiveTo observe the effect of intravitreal injection of anti-vascular endothelial growth factor drugs on the subfoveal choroid thickness (SFCT) of patients with retinal vein occlusion (RVO) and macular edema (ME). MethodsA prospective clinical study. From January 2017 to January 2019, 59 monocular RVO-ME patients with 59 eyes diagnosed in the eye examination of The First Central Hospital of Baoding were included in the study. Among them, there were 31 males with 31 eyes and 28 females with 28 eyes; the average age was 57.4±10.3 years old. The course of the disease was 5 days to 1 month, all of whom had the first-onset disease. Branch retinal vein occlusion (BRVO) was found in 35 eyes (BRVO-ME group); non-ischemic central retinal vein occlusion (CRVO) was found in 24 eyes (CRVO-ME group). Best corrected visual acuity (BCVA) and frequency domain optical coherence tomography (OCT) were performed. The BCVA examination was carried out using the international standard visual acuity chart, which was converted into the logarithmic minimum angle of resolution (logMAR) visual acuity during statistics. The Cirrus HD-OCT 5000 instrument from Carl Zeiss company of Germany was used to measure the central macular thickness (CMT) and SFCT. All eyes were treated with intravitreal injection of anti-vascular endothelial growth factor drugs. The follow-up time after treatment was 6 months, and the changes of BCVA, CMT and SFCT of eyes before treatment and 2 weeks after treatment were compared and observed, as well as the occurrence of treatment-related complications. The comparison of BCVA, CMT, and SFCT at different times before and after treatment were adopted repeated measures analysis of variance; pairwise comparison of differences at different time points adopts the least significant difference t test. ResultsBefore treatment, the average logMAR BCVA and CMT of RVO-ME eyes were 0.92±0.46 and 604.71±169.35 μm, respectively. At 2 weeks, 1, 3, and 6 months after treatment, the average logMAR BCVA of the affected eye was significantly improved compared with that before treatment, and the CMT was significantly decreased. The difference was statistically significant (F=55.664, 59.518; P＜0.05). Before treatment, the average SFCT of the affected eye and the contralateral eye of RVO-ME patients were 306.3±65.8 and 241.3±59.8 μm, respectively. The SFCT of the affected eye was significantly thicker than that of the contralateral healthy eye, and the difference was statistically significant (t=25.772, P＜0.05). At 2 weeks, 1, 3, and 6 months after treatment, the average SFCT of the eyes were 267.7±81.4, 252.3±57.3, 239.2±46.5, 240.6±48.3 μm, respectively. Compared with before treatment, treatment SFCT decreased significantly at different times afterwards, and the difference was statistically significant (F=924.341, P＜0.001). There was no significant difference in SFCT between CRVO-ME group and BRVO-ME group at 2 weeks, 1, 3, and 6 months after treatment (P＞0.05). No complications such as endophthalmitis, cataract progression and neovascular glaucoma occurred during the follow-up period of all eyes. ConclusionThe SFCT of eyes with short course of disease and first-onset RVO-ME is thickened; anti-VEGF drug treatment can effectively reduce SFCT, improve ME, and increase BCVA.