High-Dose (2.5 mg) Intravitreal Bevacizumab as Rescue Therapy for Persistent Postradiation Cystoid Macular Edema

Background/aims: To investigate the efficacy of intravitreal high-dose (2.5 mg/0.1 mL) bevacizumab as rescue therapy for postradiation cystoid macular edema (CME) resistant to standard-dose (1.25 mg/0.05 mL) bevacizumab.

Methods: Retrospective, interventional case series.

Results: Fifteen eyes of 15 patients were included. Eyes were treated with a mean of 10 standard-dose (1.25 mg) bevacizumab injections but failed to show CME resolution. Following 3 monthly treatments of high-dose (2.5 mg) bevacizumab, mean central macular thickness (CMT) reduced significantly from 406 ± 100 to 360 ± 83 μm (p = 0.01) and mean logMAR visual acuity improved from 0.55 ± 0.17 (Snellen 20/71) to 0.48 ± 0.21 (Snellen 20/60, p = 0.07). At the final follow-up of 9 months, CMT was 395 ± 124 μm (p = 0.67) and visual acuity was 0.51 ± 0.23 (Snellen 20/65, p = 0.22). Five eyes (30%) had a >10% reduction in CMT at the final follow-up. In these eyes, the observed CMT reduction was statistically significant (p = 0.04) and logMAR visual acuity was significantly better (p ≤ 0.01) compared to the remainder of the cohort.

Conclusions: Overall, the use of high-dose (2.5 mg) bevacizumab did not result in a sustained, significant improvement in CMT and visual acuity outcomes following incomplete response to standard-dose (1.25 mg) bevacizumab. However, a minority of eyes exhibited favorable response with significant CMT reduction.