Reversible Vision Loss Following Closantel Poisoning: A Rare Case Report with OCT Correlation

Background: Closantel is a veterinary anthelmintic agent classified under salicylanilides.Human poisoning is extremely rare but can result in serious systemic and visual toxicity.Case presentation: We report the case of a 22-year-old female who accidentally ingested approximately 4.5 grams of closantel solution (15%).She presented with severe vomiting but stable vital signs and no initial visual complaints.Gastric lavage and supportive care were administered.On the 8th day post-ingestion, she developed sudden bilateral blurring of vision.Optical coherence tomography (OCT) revealed disruption in the outer retinal layers.She was treated with intravenous methylprednisolone, resulting in significant visual improvement within 48 hours.Conclusion: Closantel poisoning in humans can lead to delayed-onset visual disturbances.Prompt recognition and treatment with corticosteroids may offer visual recovery.Clinicians should consider closantel toxicity in patients with unexplained visual loss and a history of exposure to veterinary compounds.