Optical coherence tomography angiography (OCTA) detection of choroidal neovascularization (CNV) in chronic central serous chorioretinopathy (CSCR)

Abstract

Purpose: To evaluate the sensitivity of spectral-domain OCTA in detecting CNV associated with pigment epithelial detachment (PED) in chronic CSCR

Methods: Eyes that were previously diagnosed with chronic CSCR and that were receiving multimodal imaging for suspicion of CNV were prospectively recruited to receive additional ancillary imaging test using the prototype AngioVue OCTA software on a commercially-available spectral-domain OCT (SD-OCT) device to generate en-face images (OCT angiograms) (Optovue, Inc, Fremont, CA). Orthogonal registration and merging of two consecutive image sets is used to obtain 3x3mm and 6x6mm OCT angiograms. The OCTA software was used to delineate a region of interest with an inner boundary at the level of the outer aspect of the outer plexiform layer and an outer boundary at the level of Bruch’s membrane. An “artifact removal” function within the software was utilized to subtract retinal vessel shadowing from the OCT angiogram. Qualitative analysis was performed based on OCTA findings of vascular flow representing CNV and CNV appearance. Cross-sectional OCT b-scans were used to determine CNV location relative to the retinal pigment epithelium and Bruch’s membrane.

Results: Twenty-seven eyes of 23 consecutive CSCR patients demonstrating chronic CSCR and associated PED were enrolled in this study. Dye based angiography showed clear evidence of CNV in all eyes. From the eight eyes with confirmed CNV, five eyes had well-circumscribed vessels in the CNV area and three eyes showed poorly-circumscribed vessels on OCTA. Manual displacement of the outer boundary segmentation line down to the choriocapillaris level on correlating OCT b-scans was performed and allowed delineation of CNV boundaries in 6/8 eyes (75%) and feeder vessel in 2/8 (25%) eyes with CNV.

Conclusions: We demonstrated agreement between non-invasive OCTA and dye-based angiography in detecting CNV associated with chronic CSCR. This study suggests that OCTA may be a viable alternative to dye based angiography in the diagnosis of CNV in patients with chronic CSCR. Since OCTA is completely non-invasive it could at least be considered a first step in establishing the diagnosis. Future studies with larger sample size are needed to improve our understanding of this diagnostic method, and provide further information to validate this imaging technique in clinical practice.