Abstract
Purpose :
We have reported that changes in the retinal function after anti-VEGF treatments for non-ischemic central retinal vein occlusion (CRVO) (Nishimura et al. DOOP 2020). Ischemic CRVO causes severe visual impairment, but the visual acuity can be expected to improve with appropriate treatment (RAVE study). Therefore, we shall investigate differences in the functional improvement after treatments between ischemic and non-ischemic CRVO by using electroretinograms (ERGs).
Methods :
Nine eyes with ischemic CRVO and 20 eyes with non-ischemic CRVO were followed for 12 months after anti-VEGF therapy. All patients were treated with monthly injections of intravitreal aflibercept (IVA) for the initial 3 months and then treated by the treat-and-extend regimen for 12 months. The full-field ERGs were recorded according to the ISCEV standard. The focal macular ERG was recorded using a 15° circular stimulation spot placed on the macula.
Results :
IVAs were performed 6.7±1.2 and 5.9±0.5 times for ischemic and non-ischemic CRVO, respectively (P=0.04). The visual acuity (logMAR) tended to improve in ischemic CRVO without significant changes (from 0.97±0.20 to 0.77±0.19, P=0.33). In the full-field ERG, implicit times of the cone b-wave and 30Hz flicker ERGs were significantly prolonged in ischemic CRVO compared to those of non-ischemic CRVO at the baseline (P<0.05). In the focal macular ERG, the a- and b-wave amplitudes and sum of oscillatory potential amplitudes were significantly reduced in ischemic CRVO than in non-ischemic CRVO at the baseline (P<0.05). These functional alternations in ischemic CRVO did not significantly improve despite treatments.
Conclusions :
Ischemic CRVO required more IVAs than non-ischemic CRVO without significant improvement of the visual acuity in ischemic CRVO. The electrophysiological results suggest that irreversible damage took place in the macula and whole retina of ischemic CRVO. It was assumed that in the macula of ischemic CRVO, there is irreversible retinal damage extending to the cone photoreceptor cells based on irreversible amplitude reduction of all components of the focal macular ERG.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.