Optic disc edema in raised intracranial pressure. I. Evolution and resolution
M. S. Hayreh and S. S. Hayreh
Progressively growing intracranial space-taking lesions were simulated in
32 rhesus monkeys by balloons introduced into the subarachnoid space of the
temporal region. Optic disc edema (ODE) first appeared at the lower pole,
then the upper pole, then the nasal part, and last the temporal part of the
disc; severity of edema generally followed sult, most severe at the lower
pole (P less than .005). Fluorescein fundus angiography showed that
swelling of the optic disc preceded the vascular changes associated with
ODE. Raised intracranial pressure for 24 hours, or less, could cause ODE.
The atrophic part of the optic disc did not develop ODE. The studies
indicate that swelling of the optic disc is the first sign of raised
intracranial pressure and is due to swelling of the nerve fibers in the
optic disc; the various associated vascular changes are secondary.
