Analysis of vessels functionality in retinal vein occlusion treated with intravitreal ranibizumab

Abstract

Purpose: To investigate the effects of intravitreal injection of ranibizumab on retinal vessels functionality in patients with retinal vein occlusion (RVO).

Methods: Consecutive treatment-naïve patients with macular edema secondary to RVO were enrolled in this prospective study. All patients underwent a complete ophthalmic evaluation, including optical coherence tomography and dynamic and static retinal vessel analysis using the Dynamic Vessels Analyzer (DVA) before (baseline),1 week and 1 month after administration of intravitreal ranibizumab. Investigation of RVO patients were compared to age- and sex-matched control subjects.

Results: We included a total of 11 eyes of 11 patients with ME secondary to RVO (10 men; mean age 56.8±13.3 years). In RVO patients, dynamic analysis showed a significant increase of mean venous dilation form +2.46±1.03% at baseline to +3.96±1.3% at 1 week (p=0.001). At 1-week mean maximum venous and arterial dilations did not differ from control subjects. Static analysis showed a mean overall significant decrease of CRAE and CRVE from baseline to 1 week (from 174.8±22.5MU to 167.2±26.7MU [p=0.04], and from 228.4±20.7MU to 217.3±22.8 [p=0.0002]). Mean CRAE in healthy control subjects was 175.9±10.45MU, not significantly different from baseline, week-1 and month-1 of RVO eyes. Conversely, mean CRVE was 195.5±9.91 MU in healthy control subjects, significantly different from baseline, week 1 and month 1 of RVO eyes. By considering only each single occluded quadrant in the 11 RVO eyes (for a total of 29 quadrants), mean CRAE significantly decreased at 1 week (from 102.3±19.7MU to 192.7±21.6MU [p=0.003]). Mean CRVE for occluded quadrants significantly decreased at both 1 week and 1 month (from 136.4±24.5MU to 123.5±24.7MU [p<0.0001]). By considering only the non-occluded quadrants (only BRVO, for a total of 15 quadrants), mean CRAE did not change from baseline to week-1 and month-1 (from 101.8±14.2MU to 100±15.6MU and to 103.2±15MU [p=0.9]). Similarly, mean CRVE for non-occluded quadrants did not change from baseline to week-1 and to month-1 (126.1±12MU to 123.2±13.4MU and to 124.1±10.9MU [p=0.9]).

Conclusions: Using DVA in patients with RVO we found that intravitreal ranibizumab increased veins dilation (dynamic analysis), and had a vasoconstrictive effect on both arteries and veins, especially in the occluded quadrants (static analysis).