Giant Cell Arteritis: Optic Disc Infarction
Optic Disc Infarction
You are looking at a swollen optic disc. Its axoplasm has been stopped by ischemia. In this case, there has been inflammatory occlusion of the ciliary feeder vessels of the optic nerve, a common finding in giant cell arteritis. The visual loss is irreversible.
The patient experiences sudden, painless, and usually devastating loss of vision in one eye. Most individuals are aged over 70 years and have a combination of limb girdle myalgias, fever, and lassitude. These symptoms are part of a syndrome called "polymyalgia rheumatica," an idiopathic autoimmune disorder of the elderly. Other patients describe scalp tenderness and pain with chewing, manifestations of external carotid artery ischemia.
The diagnosis is further suggested by finding an elevated sedimentation rate or C-reactive protein and confirmed by finding in scalp (usually temporal) arteries on biopsy.
The diagnosis must be made immediately because there is a strong chance that the fellow optic nerve will become infarcted within days unless high-dose corticosteroid treatment is begun. This treatment is nearly 100% effective in preventing second eye involvement.
What to do?
Acute, persistent monocular visual loss in an elderly patient must be presumed to be caused by giant cell arteritis, especially if consitutional symptoms are present. If you find a swollen disc, that presumption rises astronomically.
Get confirmation immediately from an ophthalmologist, who will wish to institute high-dose (intravenous methylprednisolone 1-2 gms/24 hours or 2 mg/kg prednisone) right away and obtain a temporal artery biopsy.