A Case of Larval Oriental Eye Worm, Thelazia callipaeda, Infection Overlooked in Routine Ophthalmic Practice

Thelazia callipaeda, the oriental eyeworm, is a zoonotic parasite that primarily infects the eyes, causing symptoms such as foreign body sensation, tearing, and itching. It is transmitted by fruit flies like Phortica okadai and commonly affects dogs and cats. This case report describes an 18-year-old woman who presented with complaints of "a worm in her left eye." Despite two visits to an ophthalmology clinic, she was initially diagnosed with conjunctivitis. The patient's history of dog ownership raised the possibility of zoonotic transmission; however, the worm was not detected during clinical examinations. Eventually, the patient removed the worm herself, and it was identified as the larval stage of T. callipaeda. This case emphasizes the importance of considering T. callipaeda in patients with nonspecific conjunctivitis symptoms, especially those with a history of contact with animals. It highlights the challenges in diagnosing this rare infection due to its nonspecific presentation and the small size of the larvae. Clinicians should be aware of this possibility and conduct thorough examinations, including double eversion of the eyelids, to avoid misdiagnosis and ensure appropriate treatment.