Optic atrophy is a sign

April 1, 2010

Optic atrophy is itself not a diagnosis, but a stepping stone for further work-up.

Andrew G. Lee, MD, urged ophthalmologists to break an old habit.

"[Optic atrophy] is simply an ophthalmoscopic sign," said Dr. Lee, professor of ophthalmology, neurology, and neurosurgery, The Weill Cornell Medical College, and chairman, Department of Ophthalmology, The Methodist Hospital in Houston. "A behavior that I would like ophthalmologists to change is never to write 'Impression, optic atrophy' without an explanation. Rather they should write something like, 'Impression, optic atrophy' followed by the differential diagnosis, the suspicion for a specific etiologic cause, and the course of management."

"A complete family history is needed for the hereditary forms of the disease," he said. "For acquired forms, a complete history and eye examination are needed, with attention to uncovering evidence of previous inflammatory disease or markers for an etiology for the optic neuropathy."

Signs of optic atrophy

"There are a few distinctive signs of opticatrophy," Dr. Lee said.

For example, patients with a hereditary optic atrophy such as Leber's hereditary optic neuropathy have the characteristic pseudoedema and telangiectasias in the acute phase followed by temporal pallor in the chronic phase, and in those with autosomal dominant optic atrophy, temporal excavation and a glaucomatous appearance but static course can be seen bilaterally.

Some unusual disc vessels also can be seen in these patients. These vessels include retinochoroidal venous collaterals (i.e., "optociliary shunt vessels"), and the work-up should include an imaging study to exclude meningioma. Nettleship collaterals on the arterial side after central retinal artery occlusion (CRAO) can appear on the disc, or the retinal vessels may appear as either no vessels or "ghost" white arteries after CRAO.

The problem in the chronic phase in these cases, however, is that the vessels may be the only sign of prior CRAO, even though the optic nerve is now pale. In adults, acquired sector optic atrophy is in many cases old ischemic optic neuropathy; in patients with congenital disease who have a small nerve and sector optic atrophy, this is usually a congenital hypoplasia (e.g., the "topless" disc), he explained.

If a cause of the optic atrophy is not uncovered, imaging should be strongly considered to exclude a compressive lesion, Dr. Lee said. Do not let a quick impression become the diagnosis. Optic atrophy falls into the 1% of daily cases that is not as clear-cut as the other 99% in whom the "eye sign" (e.g., cataract, retinal detachment, glaucomatous cup, elevated IOP) is the same as the "diagnosis."

"Writing 'Impression, optic atrophy, re-examine in 3 months' without a differential diagnosis or plan is a potentially dangerous practice that could lead to delay in diagnosis of a potentially treatable intracranial etiology," he said.