Comparison of foveal avascular zone between optical coherence tomography angiography and fluorescein angiography in patients with retinal vein occlusion

by Jens Ulrich Werner, Felix Böhm, Gabriele E. Lang, Jens Dreyhaupt, Gerhard K. Lang, Christian Enders

Objective

To compare area of foveal avascular zone (FAZ) in different retinal vascular layers in optical coherence tomography angiography (OCTA) and fluorescein angiography (FA) in patients with retinal vein occlusion (RVO).

Design and methods

Prospective cross-sectional comparative study in 47 eyes of 47 patients. FA was recorded with the Zeiss FF450plusIR camera and OCTA was obtained with the Zeiss Cirrus 5000 equipped with the AngioPlex module. Area of FAZ was graded by two independent investigators and calculated with Adobe Photoshop. Analysis for the total study population as well as subgroup analysis for branch retinal vein occlusion (BRVO), central retinal vein occlusion (CRVO) and patients with and without macular edema (ME) was performed.

Results

For all patients, FAZ was 0.449 mm² in FA, 0.496 mm² in OCTA superficial capillary layer (SCL) and 3.168 in OCTA deep capillary layer (DCL). In patients without ME FAZ was 0.288 mm² in FA, 0.342 mm² in OCTA SCL and 1.384 mm² in OCTA DCL. FAZ area measurement in patients with ME revealed 0.482 mm² in FA, 0.527 mm² in OCTA SCL and 3.554 mm² in OCTA DCL.

Conclusions

Especially the SCL of OCTA shows a good agreement to FA in measurement of FAZ in all patients with low limits of variation in patients without ME. There were no considerable differences in BRVO and CRVO. OCTA could replace FA in FAZ area measurement in patients with RVO, especially in those without ME, achieving similar measurements whilst being non-invasive