Motion perception tested with reversing grating in Duane's syndrome.

Many papers have reported that motion perception asymmetry (MPA) is replaced by motion perception symmetry (MPS) by the 4th to 5th month after birth, when stereopsis starts to occur in normal infants. Duane's syndrome is a congenital motor abnormality, it does, however, reportedly show good stereopsis. We confirmed the stereopsis in Duane's syndrome and checked the motion perception (MP) by using the Reversing Grating Test to investigate if the congenital motor abnormality affects the MP in patients whose binocular sensory system is well developed. Thirty-eight Duane's syndrome patients aged 3 to 45 years were included in the present study. They were divided into 24 cases of Duane I, 9 cases of Duane II, 5 cases of Duane III. The Titmus Stereo Tests, Lang Stereotest, and TV-Random Dot Stereo Test were used to examine the stereopsis. Thirty-four patients had good stereopsis, and 4 had poor stereopsis. None of them showed MPA in any spatial frequencies (1/ 4, 1/2, 1 cycles/degree) examined. The Reversing Grating Test is useful for examining MPA in strabismus patients with eye movement limitations.