What is Papilledema?

Papilledema is optic disc swelling (usually bilateral) caused specifically by elevated intracranial pressure. 1, 2

Definition and Key Distinguishing Features

Papilledema is a descriptive term exclusively for optic disc swelling resulting from proven elevated intracranial pressure (ICP), distinguishing it from other causes of optic disc edema. 1, 2
Visual function is typically preserved in the acute phase, particularly central vision, visual acuity, and color vision early in the disease process—this is a critical distinguishing feature from other causes of optic disc swelling. 3
The condition is usually bilateral due to the systemic nature of elevated ICP affecting both optic nerves. 1

Elevated ICP is transmitted to the subarachnoid space surrounding the optic nerve, which hinders axoplasmic transport within ganglion cell axons, leading to disc swelling. 3
There is ongoing debate whether axoplasmic flow stasis results from physical compression of axons versus microvascular ischemia. 3

Elevation and blurring of the optic disc and its margins are hallmark signs. 2
Venous congestion is typically present. 2
Retinal hard exudates, splinter hemorrhages, and infarcts may be visible on funduscopic examination. 2

Patients usually present with signs or symptoms of elevated ICP, including headache (present in nearly 90% of cases), nausea, vomiting, diplopia, ataxia, or altered consciousness. 2, 4
Transient visual obscurations are common visual disturbances. 4
Pulsatile tinnitus should be specifically assessed. 4
Horizontal diplopia may occur due to sixth nerve palsy. 4

Idiopathic intracranial hypertension (IIH) is the most common cause, especially in patients under age 50, and typically affects overweight females of childbearing age. 3, 4

Cerebral venous sinus thrombosis can present with elevated ICP and requires anticoagulation rather than standard IIH management. 5
Intracranial tumors causing mass effect. 2
Subarachnoid hemorrhage and subdural hematoma. 2
Intracranial inflammation and infections. 2
Medications including tetracyclines, vitamin A and retinoids, growth hormone, thyroxine, and lithium. 5
Endocrine disorders such as Addison disease and hypoparathyroidism. 5

Some patients with raised ICP may present with visual loss and disc swelling, which can be mistakenly diagnosed as optic neuritis rather than papilledema—this is a dangerous diagnostic error. 6
When papilledema is suspected clinically, blood pressure should be measured and pseudopapilledema must be ruled out before proceeding with further workup. 3

Confirmation typically requires thorough ocular examination including visual field testing. 1
Optical coherence tomography (OCT) is increasingly valuable for detecting subclinical peripapillary retinal nerve fiber layer (pRNFL) thickening that might be missed with ophthalmoscopy alone. 7
MRI of the brain and orbits with MR venography is the preferred neuroimaging modality to identify indirect signs of increased ICP and rule out nonidiopathic causes. 3, 8
Lumbar puncture with measurement of opening pressure (elevated >250 mm H₂O in adults) and evaluation of CSF composition is required for definitive diagnosis. 3, 4

Joint care between ophthalmologists and neurologists is essential for treating the underlying condition and managing visual dysfunction and headache. 1
Treatment must be targeted toward the underlying etiology of elevated ICP. 3
For IIH specifically, weight loss and acetazolamide are first-line therapies. 3, 5
Rapidly declining visual function requires urgent surgical intervention to preserve vision. 4, 5