The authors present a retrospective, interventional case series investigating the efficacy of high dose (2.5mg/0.1ml) intravitreal bevacizumab in the treatment of persistent postradiation (Iodine-125 plaque brachytherapy for uveal melanoma) cystoid macular oedema (CME). Persistent CME was defined as increased or stable central macular thickness (CMT) on ocular coherence tomography (OCT) compared to baseline despite a minimum of three monthly injections of standard dose (1.25mg/0.05ml) bevacizumab. Inclusion criteria included: patients who had been treated with at least three monthly injections of the high dose (2.5mg) bevacizumab for persistent CME following failure of the standard dose (1.25mg); with injections given at monthly intervals and not extending time intervals.
Primary study outcomes included: change in visual acuity and CMT following monthly treatment with 2.5mg bevacizumab at three months and final follow-up. Fifteen eyes of 15 patients were included in the study. All patients were Caucasian (10 female, 5 male) with a diagnosis of choroidal melanoma and mean patient age was 56 years (range 41-70 years). All patients showed persistent CME after a median of 10 injections of standard dose bevacizumab per eye at monthly intervals. Mean baseline parameters in the affected eye at initiation of 2.5mg bevacizumab were: LogMAR visual acuity 0.55 +0.17 (range 0.30-0.88) and CMT was 406 +100 μm (range 283-664). After three monthly injections of 2.5mg bevacizumab, mean LogMAR visual acuity improved to 0.48 +0.21 (p=0.07) and CMT decreased to 360 +83 μm (-14.6%; p=0.01). At final follow-up (mean nine months; range four to 18), mean LogMAR visual acuity was 0.51 +0.23 (p=0.22) and mean CMT was 394 +124 μm (-8% overall; p=0.67). Five eyes (30%) had a >10% reduction in CMT and improved visual acuity. Thinner tumours postradiation were associated with a more favourable treatment response. Remaining eyes were stable (within one Snellen line and 10% CMT of baseline), and two eyes worsened (>1 line loss and >10% increase of baseline CMT) at final follow-up.
Overall, the use of high dose bevacizumab in eyes with persistent postradiation CME resistant to the standard dose did not result in a sustained, significant improvement in CMT and visual acuity. However, it may be effective in select patients with further evaluation of tumour characteristics, clinical associations and radiation factors predictive of treatment response. Limitations of the study included: retrospective analysis in a small number of cases; information on the presence / absence of macular ischaemia was not available for all patients; and non standardised treatment comprising prophylactic bevacizumab and / or corticosteroids prior initiation of high dose bevacizumab.
