Choroidal blood flow after the first intravitreal ranibizumab injection in neovascular age-related macular degeneration patients.

Abstract

To analyse choroidal blood flow (ChBF) changes after the first intravitreal ranibizumab injection in naïve, age-related macular degeneration (ARMD) patients. Subfoveal ChBF was assessed by laser Doppler flowmetry (LDF) in newly diagnosed ARMD patients. Both treated and untreated eyes were assessed in each subject at each visit before the first intravitreal ranibizumab injection as well as 24hr (day 1) and 7days after (day 7). Central macular thickness (CMT), best-corrected visual acuity (BVCA), systemic haemodynamic parameters and LDF parameters were evaluated at each visit. Nonparametric tests were used to compare data between visits and between treated and untreated eyes. Seventeen ARMD patients were included (12 women and five men, 78±8years old). At day 7 postintravitreal ranibizumab injection, the normalized choroidal blood velocity (ChBVel) change in the treated eye group was significant (-10.2%; p=0.006). The choroidal blood volume (ChBVol) did not change significantly after intravitreal injection of ranibizumab. There was a trend for a reduction in ChBF at day 7 (-9.1%, p=0.08). The sensitivity of the experiment was 12% for ChBVel, 16% for ChBVol and 9% for ChBF. In conclusion, the laser Doppler technique provides feasible and noninvasive measurements of blood flow parameters before and after intravitreal injection of antivascular endothelial growth factor (anti-VEGF) in patients with exudative ARMD. Choroidal blood velocity decreased as early as 7days after intravitreal ranibizumab injection, suggesting a vasoconstriction effect of anti-VEGF in large choroidal vessels in front of choriocapillaris (the site of LDF measurement).