Correlation Between Serum Vascular Endothelial Growth Factor-A (VEGF-A) Levels and Optical Coherence Tomography Angiography Parameters in Exudative Age-Related Macular Degeneration

Background and objective: Among inflammatory and angiogenic cytokines, VEGF-A has been recognized as a driver of increased vascular permeability in eyes with exudative age-related macular degeneration (ExARMD).The study aimed to evaluate the correlation between serum vascular endothelial growth factor-A (VEGF-A) levels and optical coherence tomography angiography (OCTA) parameters in ExARMD.Methodology: In this prospective, single-arm, before-and-after interventional study, treatment-naïve eyes with ExARMD underwent assessment of best-corrected visual acuity (BCVA), central foveal thickness (CFT), subfoveal choroidal thickness (SFCT), and OCTA parameters, including foveal avascular zone (FAZ) and vessel density (VD) of different slabs of retina and choroid.The serum VEGF-A levels were measured with commercially supplied enzyme-linked immunosorbent assay (ELISA) kits according to the manufacturer's protocol.Correlations between serum VEGF-A levels and ocular parameters were evaluated before and at one month after a single intravitreal injection of 0.5 mg/0.05mL ranibizumab biosimilar.Results: The study involved 36 eyes from 25 ExARMD patients, with a mean age of 63.9 ± 7.68 years.At baseline, the distance BCVA was LogMAR 1.1 ± 0.6, CFT was 367.0 ± 237.1 (median: 294.0 (IQR: 219.5 to 395.0)) microns, SFCT was 262.9 ± 71.6 (median: 263.5 (IQR: 223.0 to 292.0)) microns, and serum VEGF-A levels were 221.1 (IQR: 130.0 to 355.7) pg/mL.Before treatment, VEGF-A levels correlated negatively with CFT (Rho = -0.236)and FAZ perimeter (Rho = -0.039)but positively with LogMAR BCVA (r = 0.190), SFCT (r = 0.243), FAZ area (Rho = 0.153), circularity (r = 0.437), and VD of most retino-choroidal layers.One month after treatment, the distance BCVA was LogMAR 0.8 ± 0.5, CFT was 324.9 ± 208.0 (median: 284.0 (IQR: 183.5 to 426.5) microns, SFCT was 240.4 ± 68.5 (median: 241.5 (IQR: 180.0 to 288.5) microns, and serum VEGF-A levels were 207.2 (IQR: 106.3 to 423.9) pg/mL.The VEGF-A levels correlated negatively with FAZ area (Rho = -0.016),perimeter (Rho = -0.033),and circularity (r = -0.170)but positively with LogMAR BCVA (r = 0.025), CFT (r = 0.032), SFCT (Rho = 0.239), and VD of most retino-choroidal layers.None of the correlations were significant after applying Bonferroni correction.Conclusion: In an exploratory unadjusted analysis, higher serum VEGF-A was associated with worse visual acuity (VA), increased SFCT, reduced FAZ perimeter, and increased VD of most retino-choroidal layers, though the association was weak.The correlation between serum VEGF-A levels and CFT, FAZ area, and circularity changed direction following treatment.After Bonferroni correction for multiple comparisons, none of these associations remained statistically significant.