A man in his 30s presented with a 5-day history of bilateral redness, blurred vision, and photophobia. The patient had received a diagnosis of human immunodeficiency virus (HIV) infection 4 months before, with a nadir in his CD4 count of 11/μL. He started highly active antiretroviral therapy, with improvement in his CD4 count to 101/μL most recently. During the past few months, he had reported increasing fatigue and intermittent fevers thought to be owing to immune reactivation syndrome. In addition to highly active antiretroviral therapy, he received combined sulfamethoxazole and trimethoprim and azithromycin prophylaxis. His visual acuity was 20/150 OD and 20/100 OS, and intraocular pressures were 6 and 10 mm Hg, respectively. On slitlamp examination, both eyes were injected with diffuse mutton-fat keratic precipitates and had more than 50 cells per 1×1-mm slitlamp highpower beam in the anterior chamber. Results of a dilated ophthalmoscopic examination revealed bilateral vitritis, hyperemic optic nerves, and extensive whitening likely involving all layers of the retina (Figure 1). He was hospitalized and started therapy consisting of intravenous (IV) acyclovir sodium, 10 mg/kg every 8 hours, and prednisone, 30 mg/d. Samples for a laboratory workup for infectious causes were obtained. After 48 hours of treatment, his condition did not improve. Figure 1. Marked vitritis, hyperemia of the optic nerve, and coalescent areas of retinal whitening involving the posterior pole are seen in the left eye. Visual acuity is 20/100.