Efficiency analysis by mfERG and OCT of intravitreal injection with ranibizumab on diabetic macular edema

AIM: To analyze the clinical efficacy of intravitreal injection of ranibizumab(IVR) on diabetic macular edema(DME) with multifocal electroretinography(mf ERG) and optical coherence tomography(OCT).METHODS: A total of 41 patients(41 eyes) with DME were treated with IVR. The best corrected visual acuity(BCVA), mf ERG results, and OCT were analyzed to compare to the baselines at 1 wk, 1, and 3 mo after operation.RESULTS: The BCVA was significantly improved in all eyes at each time point(P<0.001). The macular area leakage and edema were reduced 1 wk and 1 mo after IVR, and the central fovea thickness(CFT) was significantly reduced compared to baseline(P<0.001). The mf ERG, twodimensional and three-dimensional images all showed that the macular fovea(1 ring) response density decreased, and the fovea and macular area spikes significantly decreased or disappeared. The amplitude density of the P1 wave was increased, and the latency of the P1 wave was shortened than preoperation(P<0.001). At 1 wk and 1 mo after the operation, there was a negative correlation between the amplitude density of P1 waves and CFT.CONCLUSION: OCT and mf ERG fully demonstrate the importance of IVR for DME patients from the macular morphology and function, especially the significance of mf ERG in this disease.