Light-adapted flicker optoretinograms captured with a spatio-temporal optical coherence-tomography (STOC-T) system

For many years electroretinography (ERG) has been used for obtaining information about the retinal physiological function. More recently, a new technique called optoretinography (ORG) has been developed. In one form of this technique, the physiological response of retinal photoreceptors to visible light, resulting in a nanometric photoreceptor optical path length change, is measured by phase-sensitive optical coherence tomography (OCT). To date, a limited number of studies with phase-based ORG measured the retinal response to a flickering light stimulation. In this work, we use a spatio-temporal optical coherence tomography (STOC-T) system to capture optoretinograms with a flickering stimulus over a 1.7 x 0.85 mm(2) area of a light-adapted retina located between the fovea and the optic nerve. We show that we can detect statistically-significant differences in the photoreceptor optical path length (OPL) modulation amplitudes in response to different flicker frequencies and with better signal to noise ratios (SNRs) than for a dark-adapted eye. We also demonstrate the ability to spatially map such response to a patterned stimulus with light stripes flickering at different frequencies, highlighting the prospect of characterizing the spatially-resolved temporal-frequency response of the retina with ORG. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

Electroretinography (ERG) has long been used for studying retinal physiological function, and recently a new technique called optoretinography (ORG) has been developed using phase-sensitive optical coherence tomography (OCT) to measure the physiological response of retinal photoreceptors to visible light. In this study, the researchers used a spatio-temporal optical coherence tomography (STOC-T) system to capture optoretinograms with a flickering stimulus and demonstrated the ability to detect differences in the photoreceptor optical path length modulation amplitudes in response to different flicker frequencies. They also showed the potential of spatially mapping the retinal response to a patterned stimulus with ORG, allowing for characterization of the spatially-resolved temporal-frequency response of the retina.