Ocular Thelaziosis: A Case Report

To report a case of ocular Thealzia callipaeda infestation and discuss the epidemiology, manifestations, and diagnosis of this entity.

We report a 33-year-old woman presented at the ophthalmology department with foreign body sensation and claiming the presence of a worm in her left eye. As risk factors, one relative had a dog and she lived in a rural area. Ocular examination showed a best corrected visual acuity of 1 in both eyes. Slit-lamp examination revealed one live worm beneath the upper eyelid, next to the lacrimal gland. No signs of keratitis or corneal erosions, neither intraocular inflammation were found. The worm was removed with forceps after topical anesthesia, and she was treated with topical antibiotics and corticosteroids for one week with a favorable recovery. Microbiological sequencing identified the parasite as Thelazia callipaeda.

Thelazia is a parasite carried and transmitted by drosophilid flies. These flies deposit larvae in the eyes of the definitive host, usually a dog and rarely a human. The species involved in human infestation are T. callipaeda, T. californiensis and T. gulosa. The first case reported in Spain was in 2011 and, to our knowledge, only 5 cases of thelaziosis have been reported in this country since then. Clinical manifestations are not very specific: foreign body sensation, redness, keratitis, corneal erosions. This, together with its low incidence, makes very important to perform a thorough examination, and suspect this pathology in patients with anterior pole symptoms and risk factors such as animal contact or rural origin.