Ophthalmomyiasis externa by Musca domestica in a case of orbital metastasis
A 70-year-old male presented with a foul smelling and discharging ulcer around the right eye of seven days duration. He complained of a crawling sensation over the area for the past two days.\nA diabetic, he was diagnosed with follicular carcinoma thyroid one year ago. He refused therapy, but came back after four months of alternative medicine treatment. In view of widespread metastasis then, he underwent chemotherapy. During the chemo, he developed painful swelling of the right eye with loss of vision and was subsequently lost to follow-up. He remained largely symptom free till the present complaints.\nOn examination of the right eye [], lids were thickened and inflammed; medial and lateral orbital walls showed deep ulcer cavities teeming with maggots; eye was proptosed down and out; exposure keratitis was present. He had no perception of light and the corneal haze precluded any fundus view.\nLeft eye anterior segment and fundus were within normal limits with a Best Corrected Visual Acuity (BCVA) of 20/20.\nHe was started on intravenous antibiotics and insulin doses adjusted to control his high glycaemic values. Under sedation, turpentine oil was instilled into the ulcer cavities and the maggots were manually picked out. The ulcers extended into the lids and inferomedially into the nose. Few maggots were caught wriggling out of the nostrils. Over 200 maggots ranging from three to ten mm size were retrieved in multiple sittings over the next three days. Sterile dressings were given. The fellow eye was thoroughly irrigated and antibiotic-steroid drops were applied following each maggot retrieving session.\nThe maggots were identified by the entomologist as those of the common housefly, Musca domestica. The patient was a coastal area inhabitant and he acknowledged that his neighbourhood with its fish markets were notorious for housefly infestation. ENT consultation showed extensive crusting of the nasal cavity, but no evidence of maggots. CT scanning [], showed a moderately enhancing soft tissue density encasing the recti and orbital apex structures, with widespread bony destruction extending to the infratemporal fossa, maxillary sinus, nasal cavity and through the lamina papyracea to the ethmoidal sinus, suggesting the possibility of metastasis from follicular carcinoma thyroid. Over the course of one week, the patient's general condition improved and the ulcer cavities filled up with healthy granulation tissue []. He was referred for palliative care.