Dr. Mark Tarnopolsky is a Professor and Division Head of Neuromuscular and Neurometabolic Disorders in the Department of Pediatrics at McMaster University. He discusses painless visual loss in a teenager betting that Leber Hereditary Optic Neuropathy is the cause.

Summary: One must consider both acquired and genetic causes for rapid visual loss in the pediatric population. Prompt treatment of optic neuritis (neuromyelitis optica, NMO) is important to identify and treat to optimize recovery. In teenage men, the possibility of Leber Hereditary Optic Neuropathy (LHON) is considered after ruling out NMO; however, what else must we consider when LHON testing is normal?  Are there any treatment options for non NMO cases and what is the possibility of visual recovery?