Posterior Ischemic Optic Neuropathy following Herpes Zoster Ophthalmicus.

Purpose: to report a case of posterior ischemic optic neuropathy (pion) following herpes zoster ophthalmicus (hzo). case report: a 58-year-old woman with history of recent hzo in her right eye presented with acute painless loss of vision in the same eye to no light perception. examination revealed a positive relative afferent pupillary defect and a normal appearing optic disc. inflammatory and infiltrative lesions of the optic nerve were ruled out by laboratory and imaging studies. the patient received systemic acyclovir and prednisolone. three months later, visual acuity improved to counting fingers, but the optic disc became pale and atrophic leading to a presumptive diagnosis of pion. considering the positive pcr test for varicella zoster virus and the short time interval between the two presentations, hzo was considered as the most probable cause of the optic neuropathy. conclusion: herpes zoster ophthalmicus can be associated with pion.