Abstract
Purpose :
The implicit times of the flicker electroretinograms (ERGs) have been shown to be significantly correlated with the degree of retinal ischemia in eyes with central retinal vein occlusion (CRVO). We have reported that the implicit times of the flicker ERGs were significantly shortened one month after the intravitreal injection of ranibizumab (IVR). The aim of this study was to determine whether repeated recordings of flicker ERGs before and after IVR can be used to monitor the degree of retinal ischemia.
Methods :
We reviewed the medical records of 19 consecutive patients with macular edema secondary to CRVO who had received IVR therapy at the Nagoya University Hospital from November 2013 to December 2014 and were followed for more than 6 months. All patients received a single IVR, and the effects were evaluated monthly by the best-corrected visual acuity and the foveal thickness determined by optical coherence tomography. Flicker ERGs were recorded monthly with the RETeval system before and after the IVR. The pupils were dilated before each ERG recording. Additional injections were given when the macular edema recurred.
Results :
The mean implicit times of the flicker ERGs at the baseline, and at 1, 2, 3, 4, 5, and 6 months after the initial treatment were 32.2±2.6ms, 30.7±2.2ms, 30.3±2.2ms, 30.5±2.1ms, 30.7±2.8ms, 30.7±2.5ms, and 30.7±2.6ms respectively. All of the implicit times were significantly shorter than that at the baseline. (P<0.05, paired t tests). The implicit time of a case that converted from non-ischemic to ischemic type during the follow-up period was markedly prolonged compared to that at the baseline (32.6 vs. 28.7ms). When a recurrence of macular edema occurred (35 re-injections in 16 eyes), the mean implicit times of the flicker ERGs were significantly longer than that at 1 month before the recurrence. (32.0±2.6ms vs. 31.3±2.5ms, P=0.04, paired t test).
Conclusions :
Repeated flicker ERG recordings before and after IVR can be used to monitor the degree of retinal ischemia in CRVO eyes.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.