Papillary edema is due to obstruction of axoplasmic flow at the level of the lamina cribrosa.

It is a nonspecific finding that may be due to multiple causes. Papillary edema may be unilateral or bilateral.

Unilateral papillary edema is characteristic of anterior optic neuritis (papillitis) and anterior ischemic optic neuropathy (AION).

The finding of bilateral papillary edema with little visual symptomatology is characteristic of intracranial hypertension.

Most optic neuropathies with bilateral papillary edema are accompanied by decreased visual acuity, impaired color vision and campimetric disturbances.

The causes are multiple including inflammatory, infectious, infiltrative, compressive, ischemic, demyelinating and toxic.