Dexamethasone intravitreal implant in the treatment of macular edema secondary to necrotizing retinitis

Purpose: To describe our experience with the use of a sustained-release dexamethasone implant in three patients with recalcitrant macular edema that developed after necrotizing retinitis in the context of the previously treated virus. Case description: Two immunocompetent patients presented with unilateral acute retinal necrosis (ARN) due to Varicella-Zoster (VZV). The other, an immunocompromised patient, presented with unilateral cytomegalovirus (CMV) necrotizing retinitis. The diagnoses were confirmed by anterior chamber polymerase chain reaction (PCR) and all were treated with oral valganciclovir and intravitreal ganciclovir (2 mg/0.1 ml). Infection was controlled but two of them required pars plana vitrectomy. Between 2 and 4 months after the resolution of signs of infection, resistant macular edema (RME) developed, and an intravitreal dexamethasone device was implanted after anterior chamber PCR had been negative. Functional and anatomical improvement was achieved, with the resolution of the edema accompanied by improvement in visual acuity in all patients. There was no evidence of reactivation at two years. No cataract or ocular hypertension was observed. One patient required two additional dexamethasone implants. Conclusion: Dexamethasone intravitreal implant could be considered as an option for the treatment of macular edema developed after ARN. Care should be taken to avoid reactivation and patients need to be properly informed.