ObjectiveTo observe the alterations of microvascular structure in patients with macular edema (ME) associated with branch retinal vein occlusion (BRVO) before and after anti-VEGF drug therapy.MethodsA retrospective case study. Thirty-two eyes of 32 patients with unilateral BRVO-ME at Department of Ophthalmology in Beijing Hospital during November 2016 to June 2018 were enrolled in this study. There were 14 males (14 eyes) and 18 females (18 eyes), with the mean age of 57.81±10.58 years, and the mean course of the disease of 12.13±7.13 d. The affected eyes was defined as the eyes with BRVO-ME. All the affected eyes received intravitreal anti-VEGF drug injections (3+PRN). BCVA and OCT angiography (OCTA) were performed on the BRVO and fellow eyes before and after intravitreal anti-VEGF drug injections. The scanning region in the macular area was 3 mm×3 mm. Macular blood flow density in the superficial capillary plexus (SCP) and deep capillary plexus (DCP), macular hemodynamics parameters [foveal avascular area (FAZ) area, perimeter (PERIM), acircularity index (AI) and vessel density within a 300um width ring surrounding the FAZ (FD-300)] and central retinal thickness (CRT) were measured in all eyes. Paired samples t-test and Univariate Linear Regression were used in this study.ResultsComparing with fellow eyes, the mean macular blood flow density measured in the entire scan was lower in BRVO-ME eyes in the SCP (t=6.589, P=0.000) and DCP (t=9.753, P=0.000), PERIM (t=4.054, P=0.000) ), AI enlarged in BRVO-ME eyes (t=4.988, P=0.000), FD-300 was lower in BRVO-ME eyes (t=2.963, P=0.006), FAZ area enlarged in BRVO-ME eyes (t=0.928, P=0.361). The blood flow density in the DCP was the parameter most significantly correlated with BCVA and FAZ area (r=0.462, −0.387;P＜ .05). After 3 intravitreal injections of anti-VEGF drug, the CRT and FD-300 decreased, BCVA increased (t=9.865, 3.256, −10.573; P＜0.05), PERIM and AI was not changed significantly (t=0.520, 2.004; P＞0.05). The blood flow density in the SCP decreased (t=2.814, P＜0.05), but the blood flow density in the DCP was not changed significantly (t=0.661, P=0.514). Contrarily, comparing with after 1 anti-VEGF drug injection, the blood flow density in the DCP increased after 2 anti-VEGF drug injections (t=3.132, P＜0.05). FAZ area enlarged in BRVO-ME eyes (t=5.340, P＜0.001). Comparing with last anti-VEGF drug injection, FAZ area enlarged after every anti-VEGF drug injection (t=2.907, 3.742, 2.203; P＜0.05).ConclusionsIn BRVO-ME eyes, the blood flow density in the SCP and DCP are decreased. The blood flow density in the DCP is positively correlated with BCVA and negatively correlated with FAZ area. After anti-VEGF drug therapy, the blood flow density is decreased in the SCP and increased in the DCP, FAZ area enlarged gradually, PERIM and AI are not changed significantly.

Citation： Li Kejia, Yu Xiaobing, Dai Hong. The alterations of microvascular structure in branch retinal vein occlusion eyes before and after anti-vascular endothelial growth factor drug therapy. Chinese Journal of Ocular Fundus Diseases, 2019, 35(1): 25-30. doi: 10.3760/cma.j.issn.1005-1015.2019.01.006 Copy