Orbital Silicone Migration Following Pars Plana Vitrectomy With Perfluorocarbon Liquid Silicone Oil Exchange and Endolaser Retinopexy in a Dog.

Abstract

OBJECTIVE: To retrospectively describe a case of orbital and periocular silicone oil migration in a dog following a 23-gauge pars plana vitrectomy with perfluorocarbon liquid (PFCL)-silicone oil (SiO) exchange. ANIMAL STUDIED: 5-year-old spayed female mixed-breed dog with phthisis bulbi OD and retinal detachment OS of undetermined etiology. PROCEDURES: The detachment OS was treated with a 23-G pars plana vitrectomy with PFCL-SiO exchange, and the patient was followed over time. RESULTS: During surgery, which transpired uneventfully, scleral ectasia was identified in the dorsolateral quadrant. 6 weeks following surgery, a non-painful, progressive exophthalmos with normal to minimally reduced retropulsion developed. Over the following 10 months, the eye developed panuveitis and progressive exophthalmos with deviation of the globe and subconjunctival infiltrate mimicking severe chemosis in addition to chronic nonulcerative keratitis. B-mode ultrasound of the orbit revealed a hypoechoic structure surrounding the posterior aspect of the globe on all sides, resulting in compression of the posterior sclera. Due to the chronic inflammatory changes and the vision loss, enucleation and orbital exploration were performed. Histopathology revealed periocular masses composed of clear spaces often lined by a single layer of flattened, polygonal to elongated cells, consistent with a final diagnosis of orbital and periocular SiO cellulitis. CONCLUSION: This is the first known report of orbital SiO migration in a veterinary species following retinal reattachment surgery. Possible causes include pre-existing scleral ectasia, incomplete closure of the scleral port sites, post-operative scleral atrophy following cautery of scleral port sites, or secondary to chronic postoperative inflammation.