Correlation of en face optical coherence tomography angiography averaging versus single-image quantitative measurements with retinal vein occlusion visual outcomes

Purpose: To demonstrate the effect of averaging multiple en face optical coherence tomography angiography images on the correlation between retinal microvasculature quantitative metrics and best-corrected visual acuity (BCVA) in eyes with retinal vein occlusion. Methods: A cross-sectional cohort with unilateral retinal vein occlusion was imaged in both eyes. Five 3 mm x 3-mm spectral domain optical coherence tomography angiography images were averaged, and quantitative parameters from averaged versus single images were correlated with logMAR BCVA. Regression analyses were performed to correlate quantitative metrics with BCVA. Results: Ten patients (5 male, average age 64.3 years) were included. Among retinal vein occlusion eyes, vessel length density was significantly less in averaged versus a single image for both the superficial retinal layer (15.5 +/- 2.5 vs. 17.8 +/- 2.4/mm, P = 0.05) and deep retinal layer (16.2 +/- 1.4 vs. 18.5 +/- 1.6/mm, P = 0.003). Multivariate linear regression showed an increased R-2 value with averaging (0.93 to 0.95, for single and averaged groups, respectively). Foveal avascular zone circularity was associated with BCVA on single images (coefficient = -0.96, P = 0.002), but not with averaged images (P = 0.063). Conclusion: Scan averaging of en face optical coherence tomography angiography images improves the clarity of vessels and may allow for more accurate quantification of vessel metrics. Quantitative metrics are significantly associated with BCVA, and averaging does not further improve this association compared with single-scan analysis.