Purpose:
To evaluate the response following initial intravitreal bevacizumab injection as a possible predictor of subsequent visual outcome in treatment of exudative age-related macular degeneration (AMD).
Methods:
A retrospective, interventional, comparative case series of patients undergoing intravitreal bevacizumab injections for treatment of exudative AMD. Inclusion criteria included treatment naïve eyes with minimum of 3 monthly injections, baseline visual acuity (VA) of 20/50 to 20/200, and minimum follow-up of 6 months. Eyes with diabetic retinopathy and choroidal neovascularization from non-AMD conditions were excluded. Snellen VA was converted to logMAR for analysis.
Results:
33 eyes from 33 patients met inclusion criteria. Patients were divided into three groups based on their response to the initial injection: improved vision (A), unchanged (B), and declined vision (C). The mean baseline logMAR VA was similar between group A (0.794, n=15) and B (0.732, n=9) (p=0.717), and was significantly different than the baseline VA of group C (0.342, n=9) (p=0.007). Patients in groups A and B experienced more visual improvement (mean change -0.270 and -0.119) over 6 months than patients in group C (mean change 0.166) (p<0.01). The mean change in VA between group A and C after the first injection was significantly different (-0.269±0.140 and 0.225±0.161 respectively, p<0.00001). After 6 months this difference continued to be significant (-0.270±0.325 and 0.166±0.183, p=0.0004).
Conclusions:
The response following initial intravitreal bevacizumab injection provides predictive value of visual outcomes in patients with exudative AMD. Patients with worse pre-treatment VA are more likely to have visual improvements following their initial injection. Patients with stable or improved VA following their initial injection are more likely to have greater visual improvement at 6 months compared to patients with declined initial VA.
Keywords: age-related macular degeneration • vascular endothelial growth factor