Evaluation of early changes of macular function and morphology by multifocal electroretinograms in patients with nasopharyngeal carcinoma after radiotherapy

Objective To assess the role of multifocal electroretinograms (mfERGs) and optical coherence tomography (OCT) for detecting early changes in macular functions of patients with nasopharyngeal carcinoma (NPC) after radiotherapy. Methods mfERGs and OCT were used to examine a NPC group (36 NPC patients after radiotherapy without clinically visible radiation retinopathy, 36 eyes) and a normal control group (25 healthy individuals, 25 eyes) with the same procedure and parameters. The two groups of mfERG were summarized by calculating ring averages, response density, N1 amplitude and P1 and N1 latencies were analysed. OCT scan thickness was summarized into ETDRS regions for comparison. Results Compared with controls, the NPC group had significantly decreased P1 response densities in 1–4 ring regions and N1 amplitudes in 1–3 rings ( P