Determinants and outcome of periocular dirofilariasis in a cohort of patients with demonstrable live worm from the ocular and adnexal parasitic granulomas
Purpose: We attempt to describe the unique diagnostic features of dirofilariasis affecting the eye, a rare disease caused by the nematode dirofilaria repens.
Case report: The cohort includes 5 adult cases of ocular dirofilariasis. Migratory oedema was present in all but one case. The occurrence of the lesions near the medial canthus in all the cases including subconjunctival mass suggests predictable pattern of migration of the worm. Absence of systemic eosinophila and lack of marked eosinophilic infiltration around the parasitic granuloma in histopathology indicates alternative immune response against the parasite. Persistence of live worm despite antihelminthic drugs can be accounted by the presence of a thick capsule which protects the filaria against adulticidal and larvicidal drugs. Surgical exicision was curative in all cases.
Conclusion: Our case series points to the importance of having high index of suspicion and early detection of ocular dirofilariasis as it is amenable to simple and effective treatment.