Papilledema is optic disc swelling that is caused by increased intracranial pressure.
The swelling is usually bilateral and can occur over a period of hours to weeks. Unilateral
presentation is extremely rare. Papilledema is mostly seen as a symptom resulting from
another pathophysiological process. In intracranial hypertension, papilledema
most commonly occurs bilaterally. When papilledema is found on fundoscopy, further evaluation
is warranted as vision loss can result if the underlying condition is not treated. Further
evaluation with a CT or MRI of the brain and/or spine is usually performed. Unilateral papilledema
can suggest orbital pathology, such as an optic nerve glioma.
Signs and symptoms
Papilledema may be asymptomatic or present with headache in the early stages. However
it may progress to enlargement of the blind spot, blurring of vision, visual obscurations
and ultimately total loss of vision may occur. The signs of papilledema that are seen using
an ophthalmoscope include: venous engorgement
loss of venous pulsation hemorrhages over and / or adjacent to the
optic disc blurring of optic margins
elevation of 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. Diagnosis
Checking the eyes for 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. Causes
Raised intracranial pressure as a result of one or more of the following:
Brain tumor, Pseudotumor Cerebri, Cerebral venous sinus thrombosis or Intracerebral hemorrhage
Respiratory failure Hypotonia
Isotretinoin, which is a powerful derivative of Vitamin A, rarely causes papilledema.
Hypervitaminosis A, in some people who take megadoses of nutritional supplements and vitamins.
Hyperammonemia, elevated level of ammonia in blood
Guillain-Barré syndrome, due to elevated protein levels
Foster Kennedy syndrome Chiari Malformation
Tumors of the frontal lobe Acute Mountain Sickness and High-altitude
cerebral edema Lyme disease.
Malignant Hypertension Medulloblastoma
Orbital Glaucoma: Central retinal vein occlusion,
Cavernous sinus thrombosis Local lesion: Optic neuritis, Ischemic optic
neuropathy, Methanol poisoning, infiltration of the disc by Glioma, Sarcoidosis and Lymphoma
Acute Lymphocytic leukemia Long periods of weightlessness for males
Pathophysiology As the optic nerve sheath is continuous with
the subarachnoid space of the brain, 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.
Treatment Historically, papilledema was a potential
contraindication to lumbar puncture, as it indicates a risk for tentorial herniation
and subsequent death via cerebral herniation, however newer imaging techniques have been
more useful at determining when and when not to conduct a lumbar puncture. Imaging by CT
or MRI is usually performed to elicit whether there is a structural cause i.e. tumor. An
MRA and MRV may also be ordered to rule out the possibility of stenosis or thrombosis
of the arterial or venous systems. The treatment depends largely on the underlying
cause. However, the root cause of papilledema is the increased intracranial pressure. This
is a dangerous sign, indicative of a brain tumor, CNS inflammation or idiopathic intracranial
hypertension 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 Cerebrospinal
fluid, or decreasing its production. Such medicines include diuretics like acetazolamide
and furosemide. These diuretics, along with surgical interventions, can also treat IIH.
In IIH, weight loss can lead to normalization of ICP.
Meanwhile, steroids can reduce inflammation, 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 exist, 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 tetracyclines and vitamin A analogues
may help decrease ICP, however this is only necessary if the medication is truly felt
to contribute to ICP increase. References
^ Cameron AJ. "Marked papilloedema in pulmonary emphysema". Br J Ophthalmol 17: 167–9. doi:10.1136/bjo.17.3.167.
PMC 511527. PMID 18169104. ^ Rich Phillips. "Astronaut feels space's
toll on his body". CNN. Retrieved 2012-03-01. ^ "Papilledema and lumbar puncture risk.".
J Neurol Neurosurg Psychiatry. 1987 August; 50(8): 1071–1074.
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