Objective To observe and evaluate the safety and efficacy of anti-vascular endothelial growth factor (VEGF) in the treatment of eyes with macular edema (ME) secondary to branch retinal vein occlusion (BRVO) in Lhasa, Tibet. MethodsA retrospective case series. From September 2018 to January 2022, a total of 41 patients (41 eyes) with BRVO-ME, who were diagnosed in Department of Ophthalmology of Tibet Autonomous Region People’s Hospital, were included in this study. There were 21 eyes in 21 males and 20 eyes in 20 females. The median age was 53 (31,75) years. There were 24 patients with hypertension (58.8%, 24/41). Best corrected visual acuity (BCVA), ocular pressure, fundus color photography and optical coherence tomography (OCT) were performed in all eyes. The BCVA was performed using the international standard logarithmic visual acuity chart, which was converted into logarithm of the minimum angle of resolution (logMAR) BCVA for record. The foveal macular thickness (CMT) was measured by OCT. All eyes were treated with intravitreous injection of anti-VEGF drugs, once a month, among which 23 eyes (56.1%, 23/41) received intravitreous injection of ranibizumab (IVR), and 18 eyes (43.9%, 18/41) received intravitreous injection of conbercept (IVC), and were grouped accordingly. There was no significant difference in age (Z=－0.447), gender composition (Z=－0.485), logMAR BCVA (t=－1.591), intraocular pressure (t=－0.167) and CMT (t=－1.290) between two groups (P＞0.05). During the follow-up, the same devices and methods were used at baseline to perform relevant examinations, and the changes of BCVA, intraocular pressure, CMT and new cardiovascular and cerebrovascular events were compared between baseline and the last follow-up. logMAR BCVA, intraocular pressure and CMT were compared between baseline and last follow-up using Student t test. The comparison of injection times and follow-up time between IVR group and IVC group was conducted by Mann-Whitney U test. ResultsAt baseline, logMAR BCVA, intraocular pressure, and CMT were 0.852±0.431, (12.5±2.5) mm Hg (1 mm Hg= 0.133 kPa), and (578.1±191.1) μm, respectively. At the last follow-up, the number of anti-VEGF drug treatments was (2.7±1.2) times; logMAR BCVA and CMT were 0.488±0.366 and (207.4±108.7) μm, respectively, with CMT > 250 μm in 14 eyes (34.1%, 14/41). Compared with baseline, BCVA (t=4.129) and CMT (t=－0.713) were significantly improved, with statistical significance (P＜0.001). The injection times of IVR group and IVC group were (2.6±0.9) and (3.0±1.5) times, respectively. There were no significant differences in the number of injection times (t=－1.275), logMAR BCVA (t=－0.492), intraocular pressure (t=0.351) and CMT (t=－1.783) between the two groups (P＞0.05). No new hypertension, cardiovascular and cerebrovascular events occurred in all patients during follow-up. At the last follow-up, there were no eye complications related to treatment modalities and drugs. ConclusionShort-term anti-VEGF treatment can improve the visual acuity of BRVO secondary ME patients and alleviate ME in Lhasa, Tibet. The safety and efficacy of ranibizumab and conbercept were similar.