Dexamethasone implants in retinal vein occlusion: 12-month clinical effectiveness using repeat injections as-needed

Objective To report the 12-month outcomes of the dexamethasone intravitreal implant in retinal vein occlusion (RVO), using an as-needed repeat injection protocol. Design Retrospective consecutive case series of 51 eyes of 49 patients with macular oedema as a result of RVO that received an intravitreal dexamethasone implant and were followed up for at least 12months. Results 70% of patients responded to dexamethasone implant injection with an improvement in visual acuity (VA) and macular oedema within 3months of injection, but only 30% of eyes gained 15 letters. The mean change in VA letter score at 12months compared with baseline for branch RVO (BRVO) and central RVO (CRVO) was 5.7 +/- 2.3 and 11.5 +/- 11.0 EDTRS letters, respectively. 56% of patients relapsed, with the median time to relapse being 17weeks for patients with branch RVO and 18weeks for patients with CRVO. Repeat injections achieved similar VA gains, but the duration of effect of repeat dexamethasone implants was much shorter at 10weeks. 14 eyes (27%) developed a significant rise in intraocular pressure, and three of these required treatment with oral acetazolamide. Four eyes with CRVO developed neovascular glaucoma during the study. Conclusions The intravitreal dexamethasone implant does not last the 6months implied by the retreatment protocol in the GENEVA trial, and improved results can be achieved with an as-needed retreatment protocol, particularly in CRVO. However, visual outcomes remain similar to those previously seen with triamcinolone in the SCORE study and neovascular complications remain a feature of CRVO.