A Simple Test of Spatial Frequency Discrimination in Patients with Multiple Sclerosis

Sharon Delle Vergin, Final year orthoptic student (Cumb)
Elaine Cornell, DipAppSc(Cumb), DOBA
Ian C.Francis, FRACS, FRACO

A simple spatial frequency decimation test was designed with gratings ranging from 0.28 to 35.0 seconds per degree of visual angle, and presented to two groups of subjects.
The first group consisted of 16 normals. The second, a group of 18 subjects from the Multiple Sclerosis Society, consisted of three with other neurological disorders and 15 with definite multiple sclerosis (MS).
Results show that the MS group was significantly less able to perform the test correctly (although the visual acuity was usually 6/9 or better) and showed a marked response of confusion, even though instructions were clearly understood.