Visual prognostic value of photopic negative response and optical coherence tomography in central retinal vein occlusion after anti-VEGF treatment

Abstract

To investigate the potential of optical coherence tomography (OCT) and photopic negative response (PhNR) for predicting visual outcome after intravitreal bevacizumab in patients with macular edema secondary to central retinal vein occlusion (CRVO). Thirty-two consecutive patients with macular edema secondary to unilateral CRVO who were treated with three times of 6 weeks interval intravitreal bevacizumab were enrolled. LogMAR visual acuity (Va), OCT and PhNR were done before and 4 weeks after first and third injection. Stepwise multiple regression analysis was conducted between pre-treatment Va, central retinal thickness, b wave amplitude, PhNR amplitude, PhNR relative amplitude (affected eye/unaffected fellow eye, % presentation) and post-treatment Va at 4 weeks after the third injection. The predictive values of pre-treatment parameters for good visual outcome (0.2 a parts per thousand currency sign LogMAR Va) were assessed using receiver-operating characteristics (ROC) analysis. In multiple regression analysis, pre-treatment Va (beta = 0.615, P = 0.001) and PhNR relative amplitude (beta = -0.352, P = 0.032) were correlated significantly with post-treatment Va. In ROC analysis, pre-treatment Va showed a 80 % sensitivity and 80 % specificity for predicting good visual outcome, at a cutoff value of 0.52 LogMAR. Pre-treatment PhNR relative amplitude demonstrated a 88 % sensitivity and 75 % specificity for predicting good visual outcome, at a cutoff value of 40.00 %. The PhNR relative amplitude can be a useful prognostic factor for visual outcome after intravitreal bevacizumab therapy in patient with macular edema secondary to CRVO. Patients with larger pre-treatment PhNR relative amplitude with better pre-treatment Va showed a better post-treatment visual outcome.