This healthy 17YO male presented with a history of decreased vision in the left eye since birth. Family and developmental history were unremarkable. Vision was 20/20 in his normal right eye and counting fingers at 10 feet in his left eye.
Color photography shows the myelinated nerve fiber layer (NFL) covering nearly the entire posterior pole and peripapillary region.
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 (Rao et al, Retina 2019;39:1125-1132).
Myelinated NFL is a relatively uncommon, unilateral or bilateral, usually isolated finding present at birth. The myelinated NFL is often connected to the optic nerve. Most patients are asymptomatic, although some may have a corresponding relative scotoma. The myelination can progress in about 10% of cases and can also resolve following retinal ischemic events.
