Comparison of congenital disc blurring and incipient papilledema in red-free light--a photographic study.

Magnified red-free photography reveals distinct differences in the appearance of the peripapillary retinae in two commonly confused conditions. Eyes with congenitally blurred disc margins have normal striated nerve fiber bundle patterns and glistening vascular highlights that are also visible with a direct ophthalmoscope and a bright red-free light source. In eyes with incipient papilledema, the peripapillary retina looses all of its superficial light reflexes and appears deep red and lusterless; stagnation of blood flow in the fundus from the effects of elevated intracranial pressure and orbital venous pressure reduces the reflecting properties of nerve flber and underlying vascular tissue. Red-free ophthalmoscopy permits accurate clinical differentiation of these omnious and innocuous types of "blurred" optic discs.