Ophthalmomyiasis interna anterior associated with Cuterebra spp in a cat

An 8-year-old domestic shorthair cat was examined for severe anterior uveitis of the right eye that was unresponsive to aggressive treatment with anti-inflammatory drugs and for a possible intraocular parasite or foreign body trapped within a large fibrin clot in the anterior chamber. Surgical exploration of a presumed entry site on the caudal aspect of the third eyelid led to keratotomy and removal of a larval parasite later identified as a first instar Cuterebra spp. Aggressive treatment with anti-inflammatory drugs was continued after surgery, and intraocular pressure was monitored closely to ensure that the cat did not develop glaucoma. Two weeks after surgery, the cat had vision in the affected eye, with resolving uveitis and a normal fundus. Six weeks after surgery, the uveitis continued to resolve; however, the cat did not have vision in the affected eye, and examination of the fundus revealed retinal atrophy. In contrast to the condition in humans, a Cuterebra spp larval infection within the eye of cats may cause not only an intense, acute inflammatory reaction, but also retinal degeneration and blindness despite prompt surgical removal.