Measurement of electroretinogram responses in OPA1-associated autosomal dominant optic atrophy using a handheld device

Purpose Autosomal dominant optic atrophy (ADOA) associated with OPA1 variants is the most common inherited optic neuropathy in the population. The utility of the Ganzfeld electroretinogram (ERG) in evaluating ADOA has not been extensively investigated. In this study, we explored the potential of using a handheld ERG device (RETeval ® ) to measure ERG responses in a cohort of patients with ADOA carrying pathogenic OPA1 mutations. Methods The Ganzfeld photopic ERG was recorded in 15 individuals with OPA1 ‐associated ADOA in response to series of flashes (200, automatically adjusted in intensity to pupil diameter) using the RETeval ® handheld ERG device and skin electrodes. Two to three series were obtained from each eye. The recordings were analysed for noise and drift manually. Both visual acuity measurements, and optical coherence tomography ganglion cell layer (GCL) and retina nerve fibre layer (RNFL) thicknesses were recorded to explore correlation with ERG parameters. Results There was a significant correlation between LogMAR visual acuity and both the a‐wave (ρ = ‐0.60, p = 0.02, n = 15) and b‐wave (ρ = ‐0.54, p = 0.04, n = 15) peak times. As a‐wave and b‐wave peak time correlated with age, a multiple linear regression analysis was performed to exclude age as a confounder. With respect to the a‐wave analysis, the coefficients for visual acuity and age were ‐0.66 (p = 0.019) and 0.015 (p = 0.14), respectively. With respect to b‐wave analysis, the coefficients for visual acuity and age were ‐1.32 (p = 0.017) and 0.028 (p = 0.16), respectively. There was no significant correlation between a‐wave and b‐wave peak times with the OCT structural parameters that were analysed. Conclusions In patients with OPA1 ‐associated ADOA, a‐wave and b‐wave peak times correlated negatively with LogMAR visual acuity, independent of the effects of age. The pathophysiological relevance of these findings requires further investigation in a larger patient cohort.