Editor's note: A number of etiologies contribute to the various optic neuropathies. Aside from the conditions listed below, glaucoma may present similarly and should be considered in the differential diagnosis. Information on demographics and symptoms appears with each neuropathy.
Manifestations
Papilledema
The optic disc swells bilaterally from increased intracranial pressure, causing the disc to appear elevated with blurred margins, microvascular congestion, retinal vein dilation and flameshaped hemorrhages. With chronically raised pressures, the disc eventually becomes gray-white with constricted blood vessels. Papilledema is most accurately differentiated from papillitis by preserved visual acuity, intact visual fields and lack of an afferent pupillary defect.
Management: Referral to a neuro-ophthalmologist is required to assess the etiology of increased intracranial pressure. Treatment and prognosis will depend on the underlying cause.
Anterior Ischemic Optic Neuropathy
The optic disc appears pale and swollen, and peripapillary splinter hemorrhages are seen. As the acute process resolves, a pale disc with or without glaucomatous cupping may result. This occurs in the sixth or seventh decade in adults with diabetes, arteriosclerosis, hypertension, hyperlipidemia and hypercoagulability. It leads to acute vision loss with altitudinal (superior or inferior) visual field defects.
Management: Although no treatment has been shown to have long-term benefit, low-dose aspirin therapy has been shown to reduce the risk of occurrence in the fellow eye. Differentiation from giant-cell arteritis is difficult, so it is necessary to rule out this condition as a cause; thus, referral for laboratory testing and possible temporal artery biopsy is warranted.
Prognosis: In more than 40% of cases, visual acuity improves spontaneously; 40% of individuals have recurrences in the fellow eye.
Optic Neuritis
The optic disc appears swollen and hyperemic. Decreased visual acuity over 2 to 7 days, pain on palpation or eye movement, visual field defect and relative afferent pupillary defect are common. Onset is usually in the third or fourth decade of life and is three times more common in women.
Management: Referral to a neuro-ophthalmologist is warranted for additional testing including an MRI. Certain patients may benefit from high-dose I.V. or retrobulbar corticosteroids, which may shorten the disease course.
Prognosis: Prognosis for return of vision within 6 weeks of the initial episode is excellent. There is a strong association for eventual development of multiple sclerosis.
Papillitis
The disc appears hyperemic with blurred disc margins, obliteration of the optic cup and distention of large veins. It is generally monocular and associated with decreased visual acuity and a relative afferent pupillary defect.
Management: Referral for neurological evaluation is necessary to evaluate underlying cause.
Giant Cell Arteritis
Fundoscopic findings are similar to anterior ischemic optic neuropathy in an adult over 60 years old with sudden vision loss or diplopia. There may be concomitant symptoms of malaise, headache, jaw pain while chewing, muscle and joint aches, fever and weight loss.
Management: This is a true medical emergency that requires urgent measurement of sedimentation rate to diagnose and treat. If ESR is elevated, the patient should be treated immediately with high-dose I.V. or oral corticosteroids to prevent complete vision loss. Temporal artery biopsy may be necessary, but treatment should be initiated while results are pending.
Prognosis: Without treatment, there is a 40% chance that the fellow eye will be affected.
Copyright Boucher Communications, Inc. Oct 2003
Provided by ProQuest Information and Learning Company. All rights Reserved
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