Swept Source OCT in Retinal Vein Occlusion

Abstract

Retinal vein occlusion (RVO) is the second-most-common retinal vascular disease after diabetic retinopathy [1]. Fluorescein angiography (FA), the current gold standard for diagnosis and management in retinal vascular diseases, provides excellent visualization of pathological alterations such as vessel leakage, non-perfusion, and neovascularization [2]. The assessment of microvasculature features and alterations using FA has been limited by the superimposition of various layers of capillary networks, as well as by capillary leakage [3]. Swept Source Optical coherence tomography angiography (SS-OCTA) is a new, noninvasive imaging modality that enables visualization of the retinal and choroidal vasculature based on isolation of motion signals (blood flow) from static (tissue) signals. Because of its high contrast and depth resolution, SS-OCTA can depict the capillary networks in specific retinal layers and allows the assessment of foveal avascular zone enlargement, capillary non-perfusion area, and vascular collateral formation. SS-OCTA en face images can be reviewed along with the structural B-scan SS-OCT to visualize changes such as increased retinal and choroidal thickness and intraretinal cysts and to correlate these with the microvascular changes visible on SS-OCTA.