Ocular dirofilariasis: a case report]

A case of ocular dirofilariasis in a female patient is presented. The zoonosis caused by parasites of the genus Dirofilaria is relatively rare in humans, with a higher incidence in south and central Europe, Asia and Africa. In Europe, dirofilariasis is mostly caused by the species Dirofilaria repens. In the past 50 years, the number of individuals involved has been on an increase, with about 780 cases reported in the literature to date. Dirofilaria is a parasite found in the dog, cat, racoon and bear. The parasite replicates in the animal's body and enters circulation in the form of microfilariae. These microfilariae reach the insect's digestive tract and are transmitted to another animal or human with subsequent mosquito bites. When transmitted to humans, the parasite is found in the skin and subcutaneous tissue, mucous membranes, and less frequently visceral organs. Concerning ocular involvement, infections of the eye and adnexa oculi and tumorous noninfectious growth of eyelid or orbit have been described to date. The symptoms of the disease vary and include local pain, proptosis, diplopia, palpebral and conjunctival edema, redness, feeling of foreign body, and impaired vision. The diagnosis is generally made by histologic identification of the parasite micro- and macroscopic characteristics, Dirofilaria DNA analysis by the method of polymerase chain reaction, and serology (ELISA) demonstrating the presence of Dirofilaria antibodies in serum. Treatment includes surgical excision of the parasite as an appropriate and efficient therapeutic procedure. A 76-old-female patient presented to outpatient ophthalmology clinic for occasional sensation of pain, rubbing and redness in her right eye. Initial therapy was introduced, resulting in short-lasting improvement. In two weeks, the patient was re-examined for recurrence of discomforts. Slit lamp examination performed temporally revealed a whitish motile, live parasite under the injected and chemotic bulbar conjunctiva. Upon surgical extirpation of the parasite, the diagnosis of dirofilariasis was verified by microbiologic identification.