[A report of the quantitative determination of relative afferent pupillary defect in central retinal vein occlusion]

Relative afferent pupillary defect (RAPD) indicates injury to the afferent pupillary nerve fibers anterior to the optic chiasma. The light attenuator composed of 2 optical polarizers was utilized to determine the RAPD quantitatively in 32 cases of central retinal vein occlusion (CRVO). In 13 cases with ischemic CRVO, 77% manifested an RAPD of 0.9 log unit or over and none less than 0.75 log unit. In contrast, among 19 cases with non-ischemic CRVO, 84% showed an RAPD of 0.65 log unit or less and none over 0.75 log unit, suggesting that RAPD was a sensitive index for differentiating ischemic from non-ischemic CRVO.