The difference of macular microvascular features in superficial and deep vascular plexi in patients with branch retinal vein occlusion

Abstract

Objective To observe the difference of macular microvascular features in superficial and deep vascular plexi in patients with branch retinal vein occlusion (BRVO). Methods A total of 63 BRVO patients (63 eyes) were enrolled in this study. There were 28 males (28 eyes) and 35 females (35 eyes). The patients aged from 39 to 74 years, with the mean age of (59.76±8.48) years. All eyes were evaluated by optical coherence tomography angiography (OCTA). The macular angiography scan protocol covered a 3 mm×3 mm area. The focus of angiography analysis included superficial vascular plexus and deep vascular plexus. The following vascular morphological parameters were assessed in these two plexi: foveal avascular zone (FAZ) enlargement, capillary non-perfusion (CNP) occurrence, microvascular abnormalities (MA) appearance, and vascular congestion (VC) signs. The FAZ area was measured by the built-in software. The macular microvascular morphology changes in superficial and deep vascular plexi were compared through McNemar test. Results The superficial and deep plexi showed FAZ enlargement in 43 eyes (68.3%) and 50 eyes (79.4%), CNP in 51 eyes (81%) and 50 eyes (79.4%), MA in 62 eyes (98.4%) and 62 eyes (98.4%), VC in 23 eyes (36.5%) and 52 eyes (82.5%), respectively. FAZ area was (0.55±0.37) mm2. There was no difference in CNP (P=1.000) and MA (P=1.000) between superficial and deep plexi. But, there was difference in FAZ enlargement (P=0.039) and VC signs (P<0.001) between superficial and deep plexi. Conclusion Deep vascular plexus showed more FAZ enlargement and VC sign than superficial plexus in BRVO patients. Key words: Retinal vein occlusion/diagnosis; Tomography, optical coherence