Abstract

A 605 g, mature, male tuatara (Sphenodon punctatus) was presented with periorbital swelling, exophthalmos, and hyphema of the right eye. Ultrasound examination showed distortion of the globe, an altered lens contour, heterogeneous vitreous content, and a loss of ocular and retrobulbar tissue planes. Computed tomography demonstrated displacement of the scleral ossicles but an absence of orbital bone lesions. A decision was made to enucleate the right eye. The tuatara was premedicated with medetomidine (0.06 mg/kg) and morphine (1 mg/kg). Intravenous alfaxalone (5 mg/kg) was administered to facilitate intubation. Maintenance anesthesia was achieved using 1–2% sevoflurane. Perioperative support included intraosseous 0.45% saline with 2% dextrose (combined 50% each) at 10 ml/kg/h and thermal support via a forced-air blanket. Transpalpebral enucleation of the right eye was performed and the excised tissue submitted for histopathologic evaluation. Postoperative analgesia was provided using morphine (1 mg/kg). Histologic sections of the excised tissue showed disruption of the anterior, posterior, and vitreous chambers attributable to the presence of abundant hemorrhage, proteinaceous fluid, and fibrin admixed with macrophages and aggregates of heterophils. This material extended between the scleral ossicles and into the extraocular skeletal muscle and surrounding glandular tissues. The lens capsule was almost completely replaced and bordered by several layers of multinucleated giant cells and epithelioid macrophages. There was extensive disruption of lens fibers. A Young's fungal stain showed large numbers of fungal hyphae in the peripheral lens fibers and in the cytoplasms of surrounding multinucleated giant cells. The histologic diagnosis was fungal panophthalmitis with phacolysis.