Optic tract syndrome with relative afferent pupillary defect.

Two cases are reported of optic tract lesions with complete homonymous hemianopia, characteristic optic atrophy and retinal nerve fiber bundle defect, and relative afferent pupillary defect (RAPD). RAPD was 0.6 log units in both cases. Infrared pupillography revealed pupillary light response of the ipsilateral side to be 1.2 or 1.3 times higher than that of the contralateral side. We confirmed that the detection of RAPD is helpful in differentiating optic tract lesions from suprageniculate lesions in cases of complete homonymous hemianopia.