Parameters associated with the size of the foveal avascular zone in healthy elderly eyes

To determine parameters related to the size of the foveal avascular zone (FAZ) in healthy elderly eyes. We reviewed the medical records of 101 normal elderly eyes with a mean age of 64.2 ± 10.1 years. A 3 × 3 mm area centered on the fovea was analyzed in optical coherence tomography angiographic images. The center of FAZ and the center of foveal photoreceptors were identified, and the misalignment between the two center points was measured. The mean FAZ size was 0.35 ± 0.12 mm2. The distance between the center of the FAZ and the center of the foveal photoreceptors was 41.6 ± 21.1 μm. The misalignment distance between the center of the FAZ and the center of the foveal photoreceptors was not significantly correlated with the size of the FAZ (r = 0.091, P = 0.3656). On the other hand, there was a significant correlation between the directionality of horizontal and vertical misalignments from the center of the foveal photoreceptors to the center of the FAZ and the FAZ size (r = -0.264, P = 0.0076 horizontal; r = 0.212, P = 0.0335, vertical). These results indicate that the larger the misalignment of the center of the FAZ from the center of the foveal photoreceptors in the temporal and superior directions, the larger the FAZ tended to be. In conclusion, analysis of parameters related to FAZ size in healthy elderly eyes may provide clues to age-related changes in macular microcirculation and early pathology in eyes with retinal diseases.