Papilledema

Papilledema is swelling of the optic disk due to increased intracranial pressure. Optic disk swelling resulting from causes that do not involve increased intracranial pressure (eg, malignant hypertension, thrombosis of the central retinal vein) is not considered papilledema. There are no early symptoms, although vision may be disturbed for a few seconds. Papilledema requires an immediate search for the cause. Diagnosis is by ophthalmoscopy with further tests, usually brain imaging and sometimes subsequent lumbar puncture, to determine cause. Treatment is directed at the underlying condition.

Papilledema is a sign of elevated intracranial pressure and is almost always bilateral. Causes include the following:

• Brain tumor or abscess
• Cerebral trauma or hemorrhage
• Meningitis
• Arachnoidal adhesions
• Cavernous or dural sinus thrombosis
• Encephalitis
• Idiopathic intracranial hypertension (pseudotumor cerebri), a condition with elevated CSF pressure and no mass lesion

Symptoms and Signs

Vision is usually not affected initially, but seconds-long graying out of vision, flickering, or blurred or double vision may occur. Patients may have symptoms of increased intracranial pressure, such as headache or nausea and vomiting. Pain is absent.

Ophthalmoscopic examination reveals engorged and tortuous retinal veins, a hyperemic and swollen optic disk (optic nerve head), and retinal hemorrhages around the disk but not into the retinal periphery. Isolated disk edema (eg, caused by optic neuritis or ischemic optic neuropathy) without the retinal findings indicative of elevated CSF pressure is not considered papilledema.

Papilledema

Image provided by James Garrity, MD.

In the early stages, visual acuity and pupillary response to light are usually normal and become abnormal only after the condition is well advanced. Visual field testing may detect an enlarged blind spot. Later, visual field testing may show defects typical of nerve fiber bundle defects and loss of peripheral vision.

Diagnosis

• Clinical evaluation
• Immediate neuroimaging

The degree of disk swelling can be quantified by comparing the plus lens numbers needed to focus an ophthalmoscope on the most elevated portion of the disk and on the unaffected portion of the retina. Swelling can also be quantified by measuring nerve fiber layer thickness using optical coherence tomography (OCT); OCT is done to quantify the degree of papilledema so that changes can be monitored.

Differentiating papilledema from other causes of a swollen optic disk, such as optic neuritis, ischemic optic neuropathy, hypotony, central retinal vein occlusion, uveitis, or pseudo swollen disks (eg, optic nerve drusen), requires a thorough ophthalmologic evaluation. If papilledema is suspected clinically, MRI with gadolinium contrast or CT with contrast is done immediately to exclude causes such as an intracranial mass. Lumbar puncture (see Lumbar puncture (spinal tap)) with measurement of CSF pressure and analysis of CSF should be done if a mass lesion has been ruled out. Lumbar puncture in patients with intracranial mass lesions can result in brain stem herniation. B-scan ultrasonography is the best diagnostic tool for the pseudo disk edema of optic nerve drusen.

Treatment

• Treatment of underlying disorder

Urgent treatment of the underlying disorder is indicated to decrease intracranial pressure. If intracranial pressure is not reduced, secondary optic nerve atrophy and vision loss eventually occur, along with other serious neurologic sequelae.

Key Points

• Papilledema indicates increased intracranial pressure.
• In addition to bilateral hyperemic and swollen optic disks (optic nerve heads), patients typically have engorged and tortuous retinal veins, and retinal hemorrhages around the disk but not into the retinal periphery.
• Funduscopic abnormalities usually precede visual disturbances.
• Do immediate neuroimaging and, if no mass lesion is seen, obtain CSF for analysis and measure CSF pressure with a lumbar puncture.
• Treat the underlying disorder.