Evaluation of microvascular network with optical coherence tomography angiography (OCTA) in branch retinal vein occlusion (BRVO)

Abstract

Background: To evaluate changes of microvascular network of macular and peripapillary regions and to provide a quantitative measurement of foveal avascular zone (FAZ) in unilateral BRVO patients. Methods: Forty-seven unilateral BRVO patients and forty-seven normal controls were enrolled. A 3*3 mm scan centered on fovea followed by a 4.5*4.5 mm scan centered on optic nerve head (ONH) were obtained in BRVO eyes, fellow eyes and control eyes of each individual using OCTA (Optovue Inc., Fremont, CA, USA). Vessel density (VD) in superficial (SVC) and deep vascular complex (DVC) of macula and radial peripapillary capillary (RPC) were automatically calculated. Parameters of FAZ region including size, perimeter, acircularity index (AI) and foveal vessel density 300 (FD-300) were measured. Results: VDs of SCV and DVC were significantly lower, especially in affected regions, in BRVO eyes compared with fellow eyes (P < 0.05). BRVO affected eyes has larger FAZ size, FAZ perimeter, AI and lower FD-300 compared with fellow eyes (all P < 0.05). VD of SVC and FD-300 were lower in fellow eyes compared with normal control eyes (P < 0.05). The average vessel density in whole area and peripapillary area in BRVO eyes were significantly lower compared with fellow eyes (P < 0.05). VD of inside disc in fellow eyes was lower than normal eyes (P < 0.05). Conclusions: OCTA provided quantitative information of vascular changes in BRVO. FAZ in BRVO eyes showed significant morphological alterations and decreases of VD in surrounding area. Decreases of VD existed not only in SVC and DVC in macular region but also in RPCs in BRVO eyes. Unaffected eyes of unilateral BRVO showed vascular abnormalities in superficial retinal layer, peri-FAZ area and also peripapillary regions.

Evaluation of the radial peripapillary capillary density in unilateral branch retinal vein occlusion and the unaffected fellow eyes

“…Sectoral RNFL thinning and reduction in RPCD in eyes with BRVO have previously been emphasized. 18 , 19 Of course, it was not surprising that we also detected decreased RNFL and RPCD in eyes with BRVO in our study. In addition, this study revealed significantly lower RPCD values in the whole image and the peripapillary region of the fellow eyes compared with that of the control eyes.…”

Longitudinal Changes on Optical Coherence Tomography Angiography in Retinal Vein Occlusion

“…While all previous studies agree on significant capillary dropout occurring in eyes with RVO compared to healthy controls [ 12 , 15 , 16 , 33 , 37 , 38 ], the data from longitudinal reports are controversial. In particular, the effect of anti-VEGF therapy on retinal perfusion is unclear, as some reports suggest it may induce vasoconstriction [ 39 , 40 ], while others show that it may improve the state of retinal perfusion [ 41 ].…”

“…Many studies have examined OCTA parameters in patients suffering from RVO, most being limited by a cross-sectional design [ 11 , 12 , 13 , 14 , 15 , 16 ]. Only a few papers have been published regarding the foveal avascular zone (FAZ) size and vessel density (VD) changes after treatment with anti-VEGF, showing contradictory results [ 17 , 18 , 19 , 20 ].…”

Macular edema after retinal vein occlusions. Macular morphometry and chorioretinal hemodynamics

“…По данным L. Chen et al [46], у пациентов с ОРВ наблюдается снижение плотности сосудов в поверхностном и глубоком сосудистом сплетении, а также перипапиллярно. Характерны значительные морфологические изменения ФАЗ и уменьшение плотности сосудов в окружающей области.…”