Presumed macular toxicity of high-dose intravitreal ganciclovir

Abstract

A 56-year-old male with bilateral cytomegalovirus retinitis was initiated on oral valganciclovir and intravitreal ganciclovir injection twice a week in first 2 weeks and once a week in subsequent weeks. An intravitreal dose of 2 mg/0.08 mL was administered in the 1st week. Considering the suboptimal response, the dose of intravitreal ganciclovir was increased to 4 mg/0.08 mL. After 4 weeks of therapy (four doses of 4-mg ganciclovir), the patient complained of worsening of vision. Fundus examination showed resolving retinitis, but the optical coherence tomography (OCT) showed neurosensory detachment (NSD) at the fovea in both eyes with inner retinal hyperreflectivity in the right eye. Considering the possibility of retinitis involving fovea, a higher dose of intravitreal ganciclovir (6 mg/0.08 mL) was administered. The patient reported further worsening of vision immediately after removing the eye patch 2 hr following the injection. OCT showed a full-thickness hyperreflective vertical band with ellipsoid zone disruption at the fovea and inner retinal hyperreflectivity in the right eye. Hyperreflective vertical band with NSD was seen in the left eye. A possibility of macular toxicity due to intravitreal ganciclovir was considered. Intravitreal therapy was stopped and oral valganciclovir was continued. At 1-month follow-up, the patient reported improvement in vision. The hyperreflectivity and NSD were resolved at month follow-up. Although higher doses of ganciclovir up to 6 mg have been used in the past, it would be better to avoid higher doses considering the development of presumed drug toxicity in our case following the use of 4 mg and 6 mg.