Relative afferent pupillary defect and edge light pupil cycle time in the early differentiation of central retinal...

A total of 37 patients of unilateral fresh central retinal vein occlusion (CRVO) of less than one month duration were examined and re-evaluated after 8 weeks. All eyes with relative afferent pupillary defect (RAPD) < or = 0.6 log units with edge light pupil cycle time (ELPCT) of 925 +/- 94 ms, visual acuity > or = 6/60 with minimal field defects proved to be of nonischemic CRVO, while eyes with RAPD > or = 0.9 log units with ELPCT of 4005 +/- 712 ms, visual acuity 3/60 with marked field defects proved to be of ischemic CRVO with evidence of retinal ischemia on fluorescein angiography. RAPD and ELPCT were found to be extremely reliable indicators for early differentiation of ischemic from nonischemic CRVO and the values remained stable over a period of time. The electroretinography (ERG) correlated well with these parameters.