Grating test of contrast sensitivity in patients with retrobulbar neuritis.

A retrospective study of 57 patients with retrobulbar neuritis (RBN) was carried out with a new test of contrast sensitivity that utilizes printed sinusoidal gratings. For 21 patients suffering from multiple sclerosis, visual abnormality was detected in 18 "affected" eyes and 12 apparently unaffected eyes. For the 36 patients with RBN, abnormalities were detected in 29. In seven of these cases, the grating test showed bilateral impairment. The grating test seemed to be a more sensitive indicator of demyellinization than other psychophysical tests. In 24 of the patients with the least severe disease, the grating test was compared with the visual evoked response. The probability of making a positive diagnosis was .54 for the evoked potential alone, and .71 for the grating test alone.