Associations between axial length and optical coherence tomography angiography biomarkers.

PURPOSE: To determine the associations between axial length (AL) and optical coherence tomography angiography (OCTA)-based eye-related parameters. METHODS: A prospective cross-sectional study of the right eye of 6953 individuals between the ages 50 and 97, with a range of AL from 19.1 to 31.7 mm was performed. Central subfield thickness (CST), foveal avascular zone (FAZ) and mean vessel density (mVD) were measured by OCTA. Associations between OCTA-based parameters, eye-related and systemic-related parameters were assessed using one-way ANCOVA, multivariable linear regression analysis and multiple regression analysis. RESULTS: AL and OCTA-based parameters were negatively correlated with age. Increased AL was associated with increased CST (ß=3.59), decreased FAZ (ß=0.02), and decreased mVD (ß=-0.4) (all p = 0.000). Better best corrected visual acuity (BCVA) was associated with larger FAZ (ß=-0.07) and higher mVD (ß=-3.160) (p = 0.002, p = 0.000). Hypertension and diabetes mellitus correlated with increased mVD (ß=0.5) and decreased mVD (ß=-0.18) respectively (p = 0.000, p = 0.023). CONCLUSION: Increased AL is associated with lower mVD which may be a potential factor between myopia and poor BCVA.