Electroretinographic studies have suggested that anti-VEGF treatment apart from its positive impact on the diabetic macular oedema may have a positive impact on the entire peripheral retinal function.
A flicker ERG recording system has recently been developed (RETeval™ LKC Technologies, Gaithersburg, MD) that makes possible to record ERGs more rapidly and less invasively than the conventional ERG systems.
We compared the amplitudes and implicit times of the flicker electroretinograms measured by the RETeval device before and after treatment with intravitreal anti-VEGF injections in eyes with diabetic macular oedema.
Methods
Prospective pilot study of 25 eyes of 23 patients with type II diabetes treated for macular oedema by intravitreal ranibizumab injections in Jules Gonin University Eye Hospital in Lausanne, Switzerland. Flicker ERGs were recorded with the novel RETevalTM system before treatment and 1 month after the 3rd injection.
Results
The mean implicit time of the flicker ERGs recorded at baseline by theRETeval system was 31.5 msec (SD: 0.7, msec). On the last follow-up examination one month after the last intravitreal injection, the implicit times of the flicker ERGs on the treated eye recorded with the RETevalTM system were significantly shortened to a mean 28 msec (SD:0.6msec) (p< 0.05; paired t-test)
Conclusion
In the present study the flicker ERGs were significantly shortened after intravitreal injections of ranibizumab for diabetic macular oedema that may indicate a functional improvement of the entire retina. The RETeval devise offers a novel, quick and easily accessible method of objective electroretinographic measurements though its clinical significance warrants further studies.