Visually Evoked Potentials in a Patient with a Fyodorov-Zuev Keratoprosthesis

PURPOSE To describe a visually evoked potential (VEP) examination performed on a patient with a keratoprosthesis. METHODS We report the case of a 60-year-old patient with a Fyodorov-Zuev keratoprosthesis in the right eye complained of gradual visual deterioration in that eye. His past medical history consisted of failed corneal graft procedures due to corneal dystrophy and an Ahmed valve implantation due to secondary glaucoma. A clinical examination and an ultrasound demonstrated vitreal opacities. In order to assess the visual status, a flash VEP test was conducted. RESULTS VEP recorded from the right eye consisted of a broadened and poorly formed positive P1 wave, with a subnormal amplitude, but a normal latency. Consequently, the patient underwent a pars plana vitrectomy. CONCLUSION This case demonstrates the viability of VEP exams in patients with keratoprostheses.