Wissenschaft & Forschung / Research Partners / In vivo optophysiology in humans

In vivo optophysiology in humans

Principle Investigator: René Werkmeister
Co-investigators: Alina Messner, Valentin Aranha dos Santos
Core-Team Member: Gerhard Garhöfer
funded by: WWTF Life Sciences LS14-067

Optophysiology summarizes tools and methods for investigating the neuronal activity of cells and measuring their structural changes. For the retina, in particular, this means the detection of scattering changes or changes in the position of specific layers, also referred to as intrinsic optical signals, in response to an optical stimulus. These signals could potentially be linked to spatially resolved retinal function and help to gain a deeper understanding of the pathogenesis of retinal diseases.

In the current project founded by the Vienna Science and Technology Fund, we investigate intrinsic optical signals induced by light stimulation by means of Fourier-domain optical coherence tomography. Due to its high resolution and spatial selectivity, the method has the potential to contribute to functional diagnostic of retinal diseases.

Measurement scheme for assessment of adaptational processes in the peripheral retina. a: Exemplary, selected region of interest in a fundus image (Optomap, Optos plc, Dunfermline, Scotland, United Kingdom). b: B-scan in the centre of the region of interest with marked area of investigation in the region of the photoreceptor outer segments. The A-scans were registered to the IS/OS junction and the B-scan was flattened. c: A-scan average - Average of all registered A-scans contained in a singular volumetric dataset of the region of interest. d-f: Measurements with varying degree of averaging before (left) and after (right) light stimulation. Scale bars correspond to 10 μm. n is the measurement number and therefore provides a non-linear axis of time. d: Flattened, native B-scans in which each column is one A-scan. e: Each tomogram was averaged along the fast axis and represents one volume. Each column in an image represents one B-scan. f: After averaging all A-scans of one volume (= A-scan average at one time point), the graph shows the optical path length change between IS/OS junction and RPE over time. Each image column represents one volume. A distinct change in optical path length after light stimulation is visible. The attribution of the reflective layers in the tomograms is as follows: The first reflective layer after the external limiting membrane (ELM, b): IS/OS junction (b-f:1); second reflective layer: the rods outer segment tips (b-f:2) and third reflective layer: RPE (b-f: 3).

Graphic from Messner et al., Scientific Reports 2019