Progressive outer retinal necrosis in a multiple sclerosis patient on natalizumab.

A 54-year-old woman with multiple sclerosis, on natalizumab, reported 2 weeks of left eye redness and blurry vision, previously diagnosed as conjunctivitis. Visual acuity was 20/125. Funduscopy revealed progressive outer retinal necrosis (figure 1), a viral retinitis of immunocompromised patients that frequently causes vision loss. Sequential bilateral involvement is common. Etiologies include varicella zoster, herpes simplex, and rarely cytomegalovirus; aqueous PCR revealed varicella. Natalizumab was held. IV and intravitreal antivirals were administered. After repair of retinitis-induced retinal detachment and resolution of retinitis, visual acuity was 20/125 (figure 2). In immunocompromised patients with ocular symptoms, clinicians should consider infectious retinitis and obtain prompt funduscopic evaluation.