Case of Ocular Thelaziasis reported in NEJM

Dr Zijing Huang and Dr Weiqi Chen at Joint Shantou International Eye Center, Shantou, China have reported a case of Ocular Thelaziasis that has been published in the New England journal of Medicine.

Thelaziasis is an Arthropod-born disease of the eye and adnexa caused by Thelazia callipaeda which is is often under-reported and not been given its due clinical importance.It is a nematode parasite transmitted by drosophilid flies to carnivores and humans. Its distribution is mainly confined to South Asian countries and Russia, and therefore it is commonly known as Oriental Eye worm.

Thelazia callipaeda was first described in 1910 from a Chinese dog and the first case of human Thelaziasis was reported in 1917, wherein four worms were extracted from the eye of Coolie in Peiping, China. Later on a case of Human Thelaziasis (HT) was reported in India from Yeroaud, Salem District in 1948.

Thelazia callipaeda (Spirurida, Thelaziidae) infects a range of definitive hosts, such as dogs, cats, foxes, rabbits, and humans; this spiruroid nematode is seen in the conjunctival sac, lacrimal gland, and lacrimal duct of these mammals.Ocular features of human Thelaziasis include excess lacrimation, irritation, conjunctivitis, keratitis, corneal ulcers, and ectropian.

According to history, a 34-year-old man presented to the ophthalmology clinic and reported having the sensation of a foreign body and itching in his right eye. He had no known medical history, and he lived on a farm with his dog. Examination with slit-lamp microscopy showed two live worms beneath the upper eyelid. A topical anesthetic was administered, and the worms were removed with the use of a fine forcep. The worms were sent to the university parasitology laboratory for examination and were identified as Thelazia callipaeda. A diagnosis of ocular thelaziasis was made. T. callipaeda, a parasitic worm that is carried and transmitted by drosophilid flies, feeds on eye secretions and deposits larvae in the eyes of the definitive host, typically a dog but occasionally a human. At follow-up 1 month after the worms had been removed, the pruritus had resolved and the patient no longer had the sensation of a foreign body in his eye. He has not reported recurrence.