Prospective Study of Vessel Density by Optical Coherence Tomography Angiography After Intravitreal Bevacizumab in Exudative Age-Related Macular Degeneration

Introduction The aim of this study was to evaluate retinal and choriocapillaris (CC) vessel density, using optical coherence tomography angiography (OCTA), in the macular region at baseline and after three once-monthly intravitreal injections of bevacizumab (loading phase) in patients affected by exudative age-related macular degeneration (AMD). Methods A total 38 eyes of 38 patients with exudative AMD (16 women, 22 men; mean age 72.47 +/- 7.46 years) were included in this study. We evaluated vessel density in different macular areas (whole image, fovea and parafovea) of the superficial capillary plexus (SCP), deep capillary plexus (DCP) and CC. In addition, central macular thickness (CMT) and choroidal thickness in the foveal region and 500 mu m in the nasal and temporal directions were analyzed by enhanced depth image-OCT. Results There were no significant differences in vessel density in the SCP, DCP and CC after the loading phase compared to baseline (p > 0.05). In contrast, CMT (p = 0.039; 320.63 +/- 175.05 vs. 372.47 +/- 167.05 mu m) and subfoveal choroidal thickness (SFCT) (p < 0.001; 189.21 +/- 37.66 mu m vs 170.37 +/- 37.96 mu m) significantly decreased after the loading phase compared to baseline. No significant correlations were found between SFCT and CC vessel density in the fovea, and between CMT and SCP and DCP (p > 0.05) at baseline and after the loading phase. Also, best corrected visual acuity did not correlate with CMT, SCP and DCP at baseline and after treatment (p > 0.05). Conclusion Macular and choroidal thickness did not correlate with vessel density, but probably correlated to vascular exudation. The anti-VEGF treatment, acting on vascular hyperpermeability, determines the reduction of the retinal and choroidal exudation, resulting in a decrease of their thicknesses. Consequently, these parameters could reflect the effectiveness of the anti-VEGF injections for treating exudative AMD respect to OCTA parameters.