Fulminant orbital myiasis in the developed world

We present, to our knowledge, the first case of orbital myiasis documented in a developed nation. Ophthalmomyiasis is a rare infection of Diptera fly larvae. The female flies have a particularly strong olfactory and visual attraction to blood, most commonly in ulcers from tumours, traumatic wounds or areas of compromised circulation.¹ Most cases of ophthalmomyiasis are limited to the larvae invading the superficial peri‐ocular tissues or penetrating the palpebra, conjunctiva or sclera. However, the most severe form of the disease, orbital myiasis, is infestation and destruction of the entire orbital cavity. Fewer than 20 cases of orbital myiasis have been published worldwide, all of them in developing countries, and usually in association with basal cell carcinoma.²,³,⁴,⁵

Case summary

A 65‐year‐old female with no past medical history initially presented to the emergency room (ER) for pain in the right eye (OD). Suspicion for orbital cellulitis was high given warmth, redness, oedema, decreased vision and restricted ocular motility OD. An orbital CT scan revealed soft tissue swelling in addition to bony erosions and a suspicious orbital mass. Biopsy of the mass showed squamous cell carcinoma without spread outside the orbit. The patient was offered exenteration at this time as a possible cure. However, she vehemently refused, so radiation therapy was undertaken and the mass was reduced 80% in size. Vision at this time was 20/40 OD.

The patient presented a second time 2 months later and vision was now 20/80 OD with an ulcerated mass just supero‐temporal to the globe. The patient again refused exenteration. The patient's vision continued to decline progressively to counting fingers and the mass continued to grow over the next 4 months when the patient again presented to the ER for irritation OD. Repeat CT scan demonstrated significant soft tissue oedema (fig 1). Examination revealed a massive infestation with maggots in the orbit OD (fig 2). Vision was no light perception OD, with a normal exam for the left eye (OS). The patient was debrided at the bedside and several maggots were removed, including over three full‐sized maggots from what remained of the globe. The patient was further debrided in the operating room. The patient refused further surgical intervention and was placed in palliative care due to systemic metastases.

Figure 1 Axial computed topography (CT) scans showing soft tissue swelling and bony erosions in the right eye (OD). In the left image it can be seen that the globe is deformed compared to the fellow eye. The radio dense linear opacity in the globe OD corresponds to intraocular infestation with maggots.

Figure 2 Clinical photograph of patient upon presentation to ER. A higher magnification photograph of the orbit of the right eye (OD) is seen on the right. Informed consent was obtained for publication of this figure.

Discussion

Although the species of these maggots was unknown, most cases of ophthalmomyiasis are caused by Dermatobia hominis (human botfly), Cochliomyia hominivorax (screw worm), Hypoderma bovis (ox warble fly) and Oestrus ovis (sheep botfly).⁶ Cuterebra (rodent botfly) larvae are native to North America.⁷ In this case treatment with debridement was sufficient, although in cases where this procedure is unsatisfactory, other authors have used petroleum jelly (to suffocate the maggots so they emerge) and paralytic agents such as ivermectin to facilitate extraction.⁸ Patients with chronic ulcerative lesions of the eye who refuse treatment, as in our case, should be warned of the rare but blinding consequence of orbital myiasis, and should be taught proper wound dressing and hygiene.