Variability of Foveal Avascular Zone Measurements Among Filipino Eyes Using Optical Coherence Tomography Angiography

Objective: To determine the foveal avascular zone (FAZ) thickness and other FAZ measurements in eyes of healthy Filipino adults aged 20-49 years. Methods: This single-center, cross-sectional, observational study evaluated 186 subjects (372 eyes) of Filipino adults 20 to 49 years of age. Using Angioplex®, the automated software of the optical coherence tomography angiography (OCTA) machine, the FAZ area, perimeter, circularity, vascular density, and perfusion in the superficial FAZ were recognized. Statistical analysis was done using SPSS version 23. The mean and standard deviation of the values of superficial capillary free zone measurements were calculated. Results: The mean FAZ area was 0.297 ± 0.112 mm2, the mean circularity was 0.667 ± 0.080, and the mean perimeter was 2.316 ± 0.80 mm. These parameters were all larger in the female population (p <0.001, p = 0.043 and p <0.001, respectively). No significant correlation was found between the FAZ area and age and between perimeter and age, but the circularity of the FAZ was inversely correlated with age (p = 0.002). The mean vessel density and vessel perfusion central were 9.767 ± 3.470 mm/mm2 and 17.008 ± 6.457 %; both were significantly lower in the female population (p = 0.005 and p = 0.003). The mean central macular thickness (CMT) was 245.895 ± 20.769 μm. CMT was noted to be higher in the male population (p <0.001). The CMT was directly correlated with age (p = 0.024). Conclusions: In eyes of healthy Filipino adults aged 20-49 years, females exhibited larger FAZ area, higher circularity, and lower CMT, compared to males. Additionally, females displayed lower central vessel density and perfusion. While FAZ area and perimeter remained stable with age, circularity decreased, and CMT increased.