Analysis of Foveal Microvascular Structures Using Optical Coherence Tomography Angiography in Age-stratified Healthy Koreans

ABSTRACT

PURPOSE: To evaluate foveal avascular zone (FAZ) microvascular structural changes in healthy Korean subjects stratified by age using optical coherence tomography angiography (OCTA). METHODS: Eighty eyes of 43 healthy volunteer subjects who had 20/20 or better best corrected visual acuity without other ocular or systemic disease except vitreous floaters and dry eye syndrome were enrolled and stratified by age group. To measure FAZ size and vascular density (VD) of the superficial capillary plexus (SCP) and deep capillary plexus (DCP), OCTA (DRI OCT Triton, Swept Source OCT, Topcon, Tokyo, Japan) scans were performed over fovea-centered 3 × 3 mm² regions, and then compared with central macular thickness (CMT) and subfoveal choroidal thickness. RESULTS: Mean age of the participants was 46.4 ± 16.1 (20–78). The SCP and DCP FAZ sizes were 0.32 ± 0.11 mm² and 0.41 ± 0.14 mm², respectively. There was a significant difference by age group (p < 0.001, p < 0.001), respectively. The FAZ VD for SCP and DCP was 28.96 ± 3.05% and 33.15 ± 3.64%, respectively. There was no difference between age groups (p = 0.118, p = 0.637). Univariate and multiple linear regression analysis showed that the FAZ size of SCP and DCP was significantly correlated with age (p = 0.039, p = 0.002) and CMT (p = 0.007, p = 0.013), respectively. The SCP and DCP FAZ size were positively correlated with age (R² = 0.279, p < 0.001, R² = 0.344, p < 0.001), and negatively correlated with CMT (R2 = 0.354, p < 0.001, R2 = 0.285, p < 0.001), respectively. CONCLUSIONS: The FAZ size of SCP and DCP increased with age and were negatively correlated with CMT. These results suggest that consideration of age and CMT is important when performing the clinical evaluation of FAZ size in healthy subjects.