Optophysiology using functional ultrahigh resolution OCT: from in vitro animal to in vivo human measurements

摘要

A functional extension of ultrahigh resolution OCT (UHR OCT) has been developed, that has the potential to establish this technique as an optical analogue to electrophysiology, by detecting depth resolved variations in optical backscattering caused by physiological tissue changes. This technique has been used to perform in vitro studies on excised, but physiologically intact, rabbit retinas and in vivo experiments on human retinas. UHR OCT has been synchronized with the white light stimulus to properly detected spatially resolved alterations in optical backscattering over time caused by light-induced intraretinal, physiological changes and has been correlated with simultaneous ERG recordings. Preliminary results demonstrate the potential of this novel extension of UHR OCT to detect time-dependent optical backscattering changes after application of a white light stimulus in specific retinal layers, especially in the inner and outer segments of the photoreceptor layer. Control experiments, including no light stimulus or application of drugs (in in vitro studies only) that inhibit the physiological responses of certain type of retinal cells confirm the physiological origin of the detected backscattering changes. Detection of cell activity and cell physiology by UHR OCT would enable a better understanding of basic physiological phenomena and may also contribute to better understanding of retinal pathogenesis.