Purpose: 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.
Methods: 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.
Results: 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).
Conclusion: 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.
Keywords: Angiography; Microvascular network; Optical coherence tomography; Retinal vein occlusion.