Specific deficits of flicker sensitivity in glaucoma and ocular hypertension.

Temporal modulation sensitivity for a 5 degree flickering field was measured in central and peripheral retina for 46 eyes with glaucoma and ocular hypertension. Prior to showing any visual field loss by conventional perimetry, 90% of patients exhibited significant losses in sensitivity around a specific frequency of about 30 to 40 Hz. Low-frequency sensitivity and critical flicker frequency were often unaffected by such losses. The central field showed almost as pronounced a loss as 20 degree in the periphery.