General Medical Information

The Eye in Systemic Disease - Neurologic Disease

Jean Edwards Holt

The ocular manifestations of systemic disease always play an important role in general medicine. Neurologic and neurosurgical diagnoses often are made from eye examinations, and the disease course is monitored with an ophthalmoscope because the eye is truly the window to the brain. Finding a fixed, dilated pupil or Marcus Gunn pupil is important. Swelling of the optic disk or true papilledema is an important ophthalmoscopic finding indicating increased intracranial pressure. A patient with papilledema has normal visual acuity, elevation of the disk with absence of the cup, blurred disk margins, venous engorgement, hyperemia of the disk, and usually hemorrhage and exudate around the disk. The presence or absence of venous pulsation is not a reliable sign. Inflammatory swelling of the optic disk (papillitis or optic neuritis), commonly a result of demyelinating disease, may appear ophthalmoscopically similar, but the patient reports markedly decreased vision due to direct nerve damage.

Optic atrophy, often described as aspirin disk, appears as a pale nerve head without normal capillaries on the surface. The presence of an atrophic nerve is sufficient to explain decreased visual acuity, but it represents only a physical finding and is not sufficient to confirm a diagnosis. The cause of optic atrophy must be established from the history or from further ophthalmoscopic or neurologic examination.