Ocular Syphilis in an Immunocompetent Patient: Through the Lens

Ocular manifestations of syphilis can occur at any stage of the disease and present with a wide range of clinical features. If left untreated, they carry a high risk of permanent vision loss. Although syphilis mainly affects individuals with human immunodeficiency virus (HIV) positive and other immunocompromised individuals, it can also present in immunocompetent individuals. A 61-year-old immunocompetent male presented with blurry vision and associated central vision loss in the left eye. Initial ophthalmologic evaluation revealed bilateral optic-disc swelling and serological tests positive for syphilis, with rapid plasma reagin (RPR) of 1:128 and positive immunoglobulin (Ig)G/IgM, confirming ocular syphilis. The patient was started on intravenous (IV) penicillin G for 14 days and required a prolonged course along with oral steroids due to persistent syphilitic uveitis. This case report highlights the importance of maintaining a low threshold for syphilis screening in patients with unexplained vision loss, regardless of their HIV status. Timely diagnosis and intervention are critical to avoid misdiagnosis and prevent irreversible visual sequelae.