Papilledema

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Papilledema
Fundal photograph showing severe papilledema in the left eye
SpecialtyOphthalmology, optometry, neuro-ophthalmology, neurology, neurosurgery

Papilledema or papilloedema is optic disc swelling that is caused by increased intracranial pressure due to any cause.[1] The swelling is usually bilateral and can occur over a period of hours to weeks.[2] Unilateral presentation is extremely rare.

In intracranial hypertension, the optic disc swelling most commonly occurs bilaterally. When papilledema is found on

MRI of the brain and/or spine is usually performed. Recent research has shown that point-of-care ultrasound can be used to measure optic nerve sheath diameter for detection of increased intracranial pressure and shows good diagnostic test accuracy compared to CT.[3] Thus, if there is a question of papilledema on fundoscopic examination or if the optic disc cannot be adequately visualized, ultrasound can be used to rapidly assess for increased intracranial pressure and help direct further evaluation and intervention. Unilateral papilledema can suggest a disease in the eye itself, such as an optic nerve glioma
.

Signs and symptoms

Fundal photograph showing severe papilloedema in the right eye.

Despite being classically referred to as a key symptom of rising intracranial pressure, papilledema is often not present in patients seen in an acute setting such as an emergency room. Many urgent cases of increased ICP only have identifiable papilledema after a day or more.[1]

Early on, papilledema may be discovered on examination with an ophthalmoscope without any changes in patient vision. It can progress to enlargement of the blind spot, blurring of vision, a concentric blind spot pattern, or diplopia (double vision). Ultimately, total loss of vision can occur, as well as other patterns of permanent injury to the optic nerve.[1]

Papilledema (right) revealed by scanning laser ophthalmoscopy (top) and laser Doppler imaging (bottom). Healthy contralateral eye (left).

The signs of papilledema that may be seen using an

ophthalmoscope
include:

  • venous engorgement (usually the first signs)
  • loss of venous pulsation
  • hemorrhages over and/or adjacent to the optic disc
  • blurring of optic margins
  • elevation of the optic disc
  • Paton's lines (radial retinal lines cascading from the optic disc)

On visual field examination, the physician may elicit an enlarged blind spot; the visual acuity may remain relatively intact until papilledema is severe or prolonged.

Causes

Raised intracranial pressure[1] as a result of one or more of the following:

Pathophysiology

As the

subarachnoid space of the brain (and is regarded as an extension of the central nervous system), increased pressure is transmitted through to the optic nerve. The brain itself is relatively spared from pathological consequences of high pressure. However, the anterior end of the optic nerve stops abruptly at the eye. Hence the pressure is asymmetrical and this causes a pinching and protrusion of the optic nerve at its head. The fibers of the retinal ganglion cells
of the optic disc become engorged and bulge anteriorly. Persistent and extensive optic nerve head swelling, or optic disc edema, can lead to loss of these fibers and permanent visual impairment.

Diagnosis

Checking the

signs of papilledema should be carried out whenever there is a clinical suspicion of raised intracranial pressure, and is recommended in newly onset headaches. This may be done by ophthalmoscopy or fundus photography, and possibly slit lamp
examination.

It is important to determine whether the observed condition is due to

optic nerve head drusen
, which can cause an elevation of the optic nerve head that can be mistaken for papilledema. For this reason, optic nerve head drusen is also called pseudopapilledema.

Treatment

Historically, papilledema was a potential

venous
systems.

The treatment depends largely on the underlying cause. However, the root cause of papilledema is the

increased intracranial pressure (ICP). This is a dangerous sign, indicative of a brain tumor, CNS inflammation or idiopathic intracranial hypertension
(IIH) that may become manifest in the near future.

Thus, a biopsy is routinely performed prior to the treatment in the initial stages of papilledema to detect whether a brain tumor is present. If detected, laser treatment, radiation and surgeries can be used to treat the tumor.

To decrease ICP, medications can be administered by increasing the absorption of

diuretics like acetazolamide and furosemide
. These diuretics, along with surgical interventions, can also treat IIH. In IIH, weight loss (even a loss of 10-15%) can lead to normalization of ICP.

Meanwhile,

steroids can reduce inflammation (if this is a contributing factor to increased ICP), and may help to prevent vision loss. However, steroids have also been known to cause increased ICP, especially with a change in dosage. However, if a severe inflammatory condition exists, such as multiple sclerosis, steroids with anti-inflammatory effects such as Methylprednisolone and prednisone
can help.

Other treatments include repeated lumbar punctures to remove excess spinal fluid in the cranium. The removal of potentially causative medicines including

analogues may help decrease ICP; however, this is only necessary if the medication is truly felt to contribute to the ICP increase.

References

External links