Purpose: To evaluate the efficacy, safety, and injection frequency of vascular endothelial growth factor (VEGF) inhibitors as used in clinical practice for the treatment of diabetic macular edema.
Methods: Multicenter (10 sites), retrospective chart review in patients (n=156) who received ≥3 anti-VEGF injections. Data collected for ≥6 months after the first injection included Snellen best-corrected visual acuity (BCVA) and central retinal thickness (CRT) by time-domain or spectral-domain optical coherence tomography (TD-OCT or SD-OCT).
Results: Mean number of anti-VEGF injections (627 bevacizumab, 594 ranibizumab, 1 aflibercept) was 5.8 (year 1), 5.0 (year 2), and 3.4 (year 3). Percentage of patients with BCVA of 20/40 or better and CRT ≤250 μm on TD-OCT or ≤300 μm on SD-OCT at the same visit (primary endpoint) ranged from 16.4% to 38.9% after the first 10 injections; 51.9%-62.3% achieved ≥20/40 BCVA and 26.2%-48.0% met CRT criteria. Therapy was well tolerated with 19 treatment-related adverse events (all ocular) reported.
Conclusion: Anti-VEGF injections were administered less frequently and were less effective than those in the ranibizumab registration trials. After each of the first 9 injections, <25% of patients achieved both BCVA of 20/40 or better and a dry macula. A substantial proportion of patients are suboptimal responders to anti-VEGF therapy; these patients may be candidates for other therapies, including intravitreal corticosteroid and laser therapy.
Keywords: bevacizumab; diabetic retinopathy; drug administration schedule; ranibizumab; vascular endothelial growth factor; visual acuity.