Optic disc edema in raised intracranial pressure. II. Early detection with fluorescein fundus angiography and stereoscopic color photography.

Optic disc edema (ODE) due to chronic intracranial hypertension was produced experimentally in rhesus monkeys. Serial studies of fundus changes at frequent intervals, by routine ophthalmoscopy, steroscopic color photography, and fluorescein angiography, revealed that swelling of the optic disc was the first sign of ODE. Other early signs were striation of nerve fibers on the optic disc margins and peripapillary retina, blurring of the disc margins, hyperemia of the disc and capillary dilation, hemorrhages, and other retinal vascular changes; these usually appeared in that sequence. The classically described signs of early ODE were almost always absent. A normal fluorescein fundus angiogram during the incipient stage did not rule out ODE. Stereoscopic color fundus photography was the most sensitive means of detecting early ODE. Fluorescein angiography did not show changes till edema was of a mild to moderate degree; routine ophthalmoscopy was the least reliable method.