Repeatability, reproducibility and agreement of foveal avascular zone measurements using three different optical...

To evaluate the repeatability, the reproducibility and the agreement of foveal avascular zone (FAZ) measurements using three different optical coherence tomography angiography (OCT-A) devices.

This prospective study included 24 eyes of 24 healthy volunteers. OCT-A imaging was performed using RTVue XR Avanti, Canon OCT-HS100 and Spectralis OCT-A. Repeated measurements were performed under the same conditions on two separate days, and the area of the FAZ was determined and analyzed using the above devices.

All three devices showed a high ICC and there was no significant difference between the ICCs (pairwise comparison) of the three devices (Optovue-Canon (p = 0.66); Canon-Heidelberg (p = 0.21); Heidelberg-Optovue (p = 0.37). Agreement analysis of the three devices revealed a significant elevation of FAZ area values with the Heidelberg device and a slight underestimation of the FAZ area with the Canon device. Nevertheless, overall we found a high level of agreement between all of the three devices (ICC ≥ 0.958 (0.905-0.982)).

Good reproducibility and repeatability were observed for all three devices. However, the agreement analysis revealed slight, but significant differences, which might limit alternating use of these devices for clinical research and follow-up examinations.