Acute retinal necrosis: time to consider double dose of Foscarnet in the first 72 hours

Purpose: To report a case of acute retinal necrosis (ARN) and to emphasize special aspects of the management. Factors that must be considered. Methods: We present the case of an 83-year-old woman examined for acute vision loss in her left eye (LE). Background: diabetes, pseudophakic in her LE; subluxated intraocular lens (IOL) and advanced pseudoexfoliative glaucoma in her right eye (RE). The visual acuity (VA) was hand movements in both eyes. Funduscopic examination revealed vitritis, temporal area of retinal necrosis with peripapillary choroiditis spots and macular haemorrhages in her LE and OCT showed a cystic macular edema. Results: A positive polymerase chain reaction (PCR) test for Varicella Zoster Virus (VZV) in aqueous humor of her LE was found. She underwent intravenous Acyclovir 10 mg per kg every 8 hours. She received two doses of adjunctive intravitreal Foscarnet (2.4 mg/ 0.1 mL) in the first 3 days of treatment (2 days between doses). After 3 days of treatment, she started with intravenous prednisone 60 mg per day. The VA of her LE was 0,8 and the retinal necrosis activity was stationary. In fundoscopic examination, vitritis and retinal hemorrhages have disappeared. At that moment there were no foci of chorioretinitis or macular edema although retinal ischemia persisted at the inferior nasal level. Conclusions: The role of adjunctive intravitreal antiviral therapy in combination with systemic treatment revealed promising results. Corticosteroids can be used topically and orally to decrease the severe inflammatory response associated with ARN. Early treatment is crucial to optimize visual and anatomic outcomes.