Evaluating the Correlation Between Optical Coherence Tomography Angiography-Derived Parameters and Serum Vascular...

Release of vascular endothelial growth factor-A (VEGF-A) is one of the mechanisms involved in the pathogenesis of central serous chorioretinopathy (CSCR). We intended to evaluate the correlation between optical coherence tomography angiography (OCTA) parameters and serum VEGF-A levels in CSCR.

Our prospective interventional study included 31 patients diagnosed with CSCR. The subjects had a mean age of 39.23±6.9 (26-53) years. They were examined for visual acuity (VA) and tested for color perception and contrast discrimination. OCT was conducted to examine central macular thickness (CMT) and subfoveal choroidal thickness (SFCT), and to detect neurosensory detachment (NSD), pigment epithelial detachment (PED), and other abnormalities. The OCTA measured foveal avascular zone (FAZ) and vessel density (VD) across various retino-choroidal layers. The serum VEGF-A levels were measured using commercially available enzyme-linked immunosorbent assay (ELISA) kits. The eyes were treated with a single intravitreal injection of 0.3 mg/0.05 ml ranibizumab biosimilar (RbB). After one month, the ocular parameters were rechecked, and serum VEGF-A levels were remeasured. We assessed the correlation between ocular parameters and VEGF-A levels in serum samples at both instances.

At baseline, the mean value of the best corrected visual acuity (BCVA) in logarithm of the minimum angle of resolution (LogMAR) was 0.81±0.43. The CMT measured 286.81±117.67 microns, SFCT 194.32±62.76 microns, and the serum VEGF-A level was 351.64 (IQR 243.57-478.71) pg/ml. Before treatment, circulating VEGF-A levels correlated positively with the LogMAR value of BCVA (Rho=0.121), CMT (Rho=0.282), SFCT (Rho=0.006), NSD height (Rho=0.100) and width (Rho=0.019), and PED number (Rho=0.016), height (Rho=0.246) and width (Rho=0.066). The serum VEGF-A showed a weak positive correlation (p>0.05) with most OCTA features, whereas it correlated negatively with FAZ area (Rho=-0.136) and perimeter (Rho=-0.128). A month after intravitreal injection, LogMAR BCVA improved to 0.42±0.42, CMT measured 256.65±109.57 microns, and SFCT was 209.84±41.53 microns. The median serum VEGF-A level was 336.31 (IQR 259.455-500.105) pg/ml. Serum VEGF-A showed weak positive correlation with LogMAR value of BCVA (Rho=0.046), CMT (Rho=0.063), SFCT (Rho=0.094), NSD number (Rho=0.290), height (Rho=0.269) and width (Rho=0.289), and PED number (Rho=0.306), height (Rho=0.204) and width (Rho=0.124). The serum VEGF-A showed negative weak correlations (p>0.05) with OCTA features, including FAZ metrics --area (Rho=-0.156), perimeter (Rho=-0.114), and circularity (Rho=-0.335), as well as VD in various retino-choroidal layers: superficial capillary plexus (Rho=-0.282); deep capillary plexus (Rho=-0.225), outer retinal chorio-capillaries (Rho=-0.295), chorio-capillaries (Rho=-0.312) and choroid (Rho=-0.274).

Higher serum VEGF-A was associated with worse VA and increased CMT, SFCT, NSD height and width, and PED number, height, and width. An increase in VEGF-A was related to reduced FAZ area and perimeter. At baseline, higher levels of VEGF-A were accompanied by an increase in VD in all layers except the outer retina and choroid. After treatment with intravitreal RbB, a similar pattern was observed; however, increased VEGF-A was found to be coupled with decreased VD in all retino-choroidal layers, except the outer retina.