Case 2.

Case 2: This patient presented with unilateral vision loss and photopsia in the right eye, along with slight blurry vision in the left eye. Best-corrected visual acuity was 20/100 in the right eye and 20/30 in the left eye, with mild right pupillary escape. Fundus examination revealed optic disc edema and posterior placoid chorioretinitis, more pronounced in the right eye (a) than in the left eye (b). Cranial and orbital MRI scans were unremarkable. Serum aquaporin-4-IgG and MOG-IgG tests were negative. However, serum syphilis serology (rapid plasma reagin and Treponema pallidum particle agglutination tests) was positive. The patient was treated with intravenous penicillin G, leading to full resolution of symptoms after 2 weeks. IV: intravenous, MOG: myelin oligodendrocyte glycoprotein, MRI: magnetic resonance imaging