Multifocal electroretinography as a predictor of maintenance of vision after photodynamic therapy for neovascular age-related macular degeneration

Abstract

To investigate the role of multifocal electroretinography (mfERG) in predicting the outcome of photodynamic therapy (PDT) for neovascular age-related macular degeneration (AMD). Participants underwent refraction protocol VA assessment using the ETDRS logMAR chart at 1 m, Contrast Sensitivity (CS) using the Pelli-Robson chart at 1 m, fundus fluorescein angiography (FA) and mfERGs in response to 19 segments. Response to PDT was binary (1 = the loss of less than 15 letters at 12 months, 0 = the loss of 15 letters or more) and was used as the dependent variable for logistic regression analysis. Logistic regression modelling identified mfERG central segment amplitude, lesion size on FA, VA and CS as predictors of outcome (P = 0.05, 0.02, 0.01, 0.03). The model is stable and has excellent discriminability. The outcomes of this study are particularly relevant to patients in the UK who are sometimes treated with PDT alone. A larger prospective study would facilitate development of an index to predict outcome of future treatments for AMD.