Bilateral infectious optic neuritis secondary to leptospirosis: A case report and literature review

Leptospirosis, a zoonotic infection, can involve the eyes, though often unrecognized. We describe a rare case of infectious optic neuritis secondary to leptospirosis. A 25-year-old male presented with fever and headache, which resolved spontaneously, followed by sudden bilateral vision blurring with vision of 1/60 in the right eye and counting fingers in the left eye, alongside bilateral optic disc swelling. Despite no recent activities predisposing him to leptospiral infection, laboratory tests revealed leukocytosis and positive leptospiral IgM antibodies. Optical coherence tomography showed bilateral optic nerve swelling, and contrast-enhanced computed tomography of the brain and orbit indicated bilateral optic neuritis. Treated with intravenous ceftriaxone, he experienced rapid visual improvement to 6/12 within a week and had a full recovery to 6/6 at the sixth month. This case highlights the rare leptospiral infectious optic neuritis and emphasizes that early diagnosis and prompt antibiotic treatment can lead to excellent visual recovery.