External Ophthalmomyiasis: Case Reports of Two Cases Associated With Agrarian Practices

Myiasis, the infestation of humans with dipterous fly maggots, is common in the tropical countries with a large fly population.1 Ophthalmomyiasis refers to the infestation of the eye and the ocular adnexa by the larval form of dipterous flies. Based on the parts of the eye which are involved, there are three types of Ophthalmomyiasis. The first type is the Ophthalmomyiasis externa in which only conjunctiva is involved. This condition, if it is not managed in time, can lead to two other of its dreaded types, such as Ophthalmomyiasis interna (the larvae invades the ocular globe and they are found in the sub-retinal space and the vitreous cavity) and orbital Ophthalmomyiasis (invasion of the orbit).2,3 Ocular involvement or ophthalmomyiasis is seen to occur in about 5% of all cases of myiasis.2 Larvae, most commonly, attack the external surface of the eyes or ocular adnexea, e.g. the lids, conjunctiva or lacrimal ducts (external ophthalmomyiasis, EOM). Ophthalmomyiasis externa is mainly caused by sheep bot fly (Oestrus ovis). Therefore, this is more common in the farming communities.3 Very few cases of Ophthalmomyiasis externa which were caused by Oestrus ovis infestation have been reported so far from India.