Examine this patient's fundus.

History

Asymptomatic.

Examination

White, streaky patches which extend from the disc and terminate peripherally in a feather-like pattern. It may cover the retinal vessels (Fig. 85).

This patient has white streaky patches in a feather-like pattern (lesion); these are medullated nerve fibres (aetiology) and are benign (functional status).

What is the pathology?

Occasionally, the myelination of the optic nerve does not stop at the lamina cribrosa but extends on to nerve fibres surrounding the optic disc. This condition is a benign congenital abnormality known as medullated or myelinated nerve fibres. It terminates

peripherally in a feather-like margin with fine striations from the course of the nerve fibre

layer.