A 14-year-old boy was referred to us because of ocular and periocular pain with photophobia in his right eye for the last 5 days. Aside from atopic dermatitis, his medical history was unremarkable. Best-corrected visual acuity was 20/20 OU. Slitlamp examination of the right eye disclosed conjunctival hyperemia and ciliary congestion, anterior chamber flare 2+, and a few nongranulomatous keratic precipitates; the left anterior segment was quiet. Intraocular pressure was 15 mm Hg OU. Pupillary light responses were normal. Dilated fundus examination revealed 1+ of vitritis (binocular indirect ophthalmoscopy score) in the right eye and swelling of the optic disc in both eyes, to a greater extent in the right eye (Figure, A). Routine blood tests, including full blood cell count, plasma glucose levels, liver function test, and kidney function test, were performed on the same day and showed a serum creatinine level of 1.57 mg/dL (reference range: 0.5-1.0 mg/dL; to convert to micromoles per liter, multiply by 88.4). Antibodies anti–Treponema pallidum were tested and the results were negative.