This 20 YO male has a large area of myelinated nerve fiber layer (NFL) extending superiorly from the left optic nerve.
This relatively uncommon and usually isolated finding is present at birth. Most patients are asymptomatic, although some may have a corresponding relative scotoma.
Myelination can progress in about 10% of cases and can also resolve following retinal ischemic events.
Learning Points:
Myelinated NFL occurs when retinal nerve fibers develop a myelin sheath, which usually stops posterior to the lamina cribrosa. The myelination may represent an oligodendrocytic choristoma.
