Differential microvascular assessment of retinal vein occlusion with coherence tomography angiography and fluorescein...

To compare the imaging of retinal vein occlusion (RVO) with optical coherence tomography angiography (OCTA) and fluorescein angiography (FA) and evaluate their roles in clinical management.

RVO patients who underwent imaging with both FA and OCTA from 1 June 2015-31 December 2015 were enrolled. An independent retinal specialist blinded from patient identity assessed the FA and OCTA reports. The pixel counting technique was used for FAZ size measurement. A significant level of p < 0.05 was taken for correlation and agreement analysis.

On OCTA, the mean FAZ size was 0.382 ± 0.152 mm² and 0.606 ± 0.136 mm² for the superficial and deep retinal layers, respectively, with significant correlation (p = 0.004). On FA, the mean FAZ size was 0.352 ± 0.158 mm², better correlated with OCTA at the superficial (p = 0.062) than the deep retinal layer (p = 0.122). Between FA and OCTA, good agreement was found for microaneurysms (100%, p = 0.001) and venous congestion (83.33%, p = 0.028), but not capillary non-perfusion (p = 0.217) and venous tortuosity (p = 0.546). OCTA also revealed more capillary non-perfusion than FA (91.67 vs. 58.33%). The presenting best-corrected visual acuity was significantly correlated with capillary non-perfusion on OCTA (p = 0.001).

OCTA and FA are complementary tools in RVO assessment. While OCTA is more precise in the assessment of FAZ and capillary non-perfusion, FA offers better vascular imaging of the peripheral retina.