Previous reports have suggested that diphenylhydantoin may improve visual field loss resulting from ischemic disease of the optic nerves. Therefore, 15 patients with residual visual impairment after acute, presumably ischemic, optic neuropathy were treated alternately with diphenylhydantoin sodium and placebo in a double-blind study. Neither visual acuity nor visual fields improved during treatment. The importance of careful quantitative perimetry with preliminary repetitive testing until results are reproducible is stressed.
Ellenberger C, Burde RM, Keltner JL. Acute Optic NeuropathyTreatment With Diphenylhydantoin. Arch Ophthalmol. 1974;91(6):435-438. doi:10.1001/archopht.1974.03900060449003