Early electroretinography in unilateral central retinal vein occlusion as a predictor of rubeosis iridis
S. B. Kaye and S. P. Harding
Department of Ophthalmology, St Pauls Eye Hospital, Liverpool, England.
Twenty-six patients with clinically nonischemic unilateral central retinal
vein occlusion and four in whom clinical categorization was unclear were
recruited. The scotopic electroretinogram (ERG) was recorded at
presentation to a range of six different luminances. Patients were followed
up for six months to assess the correlation between initial ERG response
and subsequent outcome. Seven patients developed rubeosis iridis. The
b-wave implicit time was the parameter most significantly associated with
subsequent rubeosis, followed by b-wave/a-wave amplitude ratio and then
b-wave amplitude. Neither a-wave amplitude nor implicit time was a valuable
predictor. The b-wave implicit times were equally predictive of rubeosis at
each of the luminances used. In individually affected eyes, a b-wave
implicit time at presentation, averaged across the range of luminances
used, of greater than 47.17 ms was strongly associated with later rubeosis,
as was an intereye difference of greater than 7.39 ms.
