Long-duration volumetric optoretinography enables measurement of retinal recovery dynamics after photostimulation

Optoretinography (ORG) typically measures rapid photoreceptor responses, limiting investigation of slower retinal recovery processes. Here, we demonstrate long-duration volumetric ORG using customized high-resolution spectral-domain optical coherence tomography with repeated volumetric acquisition. Spatial averaging across the retinal volume improves sensitivity to both light-evoked scattering and outer segment (OS) optical path length (OPL) changes, while automated deep learning-based segmentation enables efficient analysis of large four-dimensional (4D) datasets. In vivo experiments in mice reveal distinct phases of retinal recovery dynamics extending over 30 min after photostimulation. Preliminary comparative measurements further reveal altered recovery behavior and an attenuated early OS OPL response in aged mice. This work establishes long-duration volumetric ORG as a platform for functional imaging of retinal physiological recovery dynamics in vivo.