Background/aims To assess the reproducibility and repeatability of foveal avascular zone (FAZ) area measurements using optical coherence tomography angiography (OCT-A) in healthy subjects.

Methods Sixty healthy volunteers (60 eyes) were subjected to FAZ area measurements by means of high speed and high resolution spectral-domain OCT (SD-OCT) XR Avanti with the split-spectrum amplitude decorrelation angiography algorithm by two experienced examiners in two different sessions.

Results The mean±SD age of the subjects was 28.9±7.6 years. Overall FAZ areas measured by the first and second observer were 0.251±0.096 mm² and 0.252±0.096 mm², respectively. Within subjects, the coefficients of variations were 1.83% (95% CI 1.51% to 2.20%) and 1.86% (95% CI 1.33% to 2.43%) for the first and second observers, respectively. The coefficient of repeatability average measurements of FAZ area were 0.015 mm² and 0.013 mm² for the first and second observers, respectively. The intraclass correlation coefficient values were 0.997 (95% CI 0.995 to 0.998) and 0.998 (95% CI 0.996 to 0.999) for the first and second observers, respectively. Inter- and intraobserver concordance correlation coefficients ranged from 0.994 (95% CI 0.990 to 0.977) to 0.999 (95% CI 0.997 to 0.999) and from 0.997 (95% CI 0.995 to 0.998) to 0.996 (95% CI 0.994 to 0.998), respectively.

Conclusions FAZ area measurements by means of OCT-A showed excellent reproducibility and repeatability in healthy eyes. OCT-A is a non-invasive diagnostic method, and its reliability makes it an interesting potential diagnostic tool for disease detection and follow-up in retinal pathologies involving foveal microcirculation.