Compact Monocular Video‐Ophthalmoscope to Measure Retinal Reflectance Changes to Flicker Light Stimuli

• Published in: Journal of biophotonics Vol. 18; no. 6; pp. e202400494 - n/a
• Main Authors: Kolar, Radim, Vicar, Tomas, Chmelik, Jiri, Jakubicek, Roman, Odstrcilik, Jan, Nohel, Michal, Skorkovska, Karolina, Tornow, Ralf P.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY‐VCH Verlag GmbH & Co. KGaA 01.06.2025; Wiley Subscription Services, Inc
• Subjects: Adult; Blood circulation; Blood flow; Blood volume; Diabetes mellitus; Display devices; Female; Fiber optics; Flicker; fundus reflectance; Glaucoma; Humans; Irradiance; Light; light flickering; Light sources; Luminous intensity; Male; Neurodegenerative diseases; neurovascular coupling; Ophthalmoscopes; Optic nerve; optic nerve head; Photic Stimulation; Portable equipment; Reflectance; Retina; Retina - physiology; Retina - radiation effects; Retinopathy; Spatial analysis; Stimulation; Stimuli; Video Recording - instrumentation; video‐ophthalmoscopy; Young Adult; blood volume; neurovascular coupling; light flickering; fundus reflectance; optic nerve head; video‐ophthalmoscopy
• ISSN: 1864-063X; 1864-0648; 1864-0648
• DOI: 10.1002/jbio.202400494

ABSTRACT This paper describes a compact video‐ophthalmoscope (VO) designed for capturing retinal video sequences of the optic nerve head (ONH) under flicker light stimulation. The device uses an OLED display and a fiber optic‐coupled LED light source, enabling high‐frame‐rate video at low illumination intensity (12 μW/cm2). Retinal responses were recorded in 10 healthy subjects during flicker light exposure with a pupil irradiance of 2 μW/cm2. Following 20 s of stimulation, all subjects displayed changes in retinal reflectance and pulsation attenuation, linked to blood flow and volume variations. These findings suggest that increased blood volume leads to decreased retinal reflectance. Temporal analysis confirmed the ability to capture flicker‐induced retinal reflectance changes, indicating its potential for spatial and temporal analysis. Overall, this device offers a portable approach for investigating dynamic retinal responses to light stimuli, which can aid the diagnosis of retinal diseases like diabetic retinopathy, glaucoma, or neurodegenerative diseases affecting retinal blood circulation. This study presents a compact monocular VO that captures high‐frame‐rate retinal videos of the ONH during flicker light stimulation. The device demonstrated its ability to detect flicker‐induced changes in retinal parameters related to blood flow in healthy subjects, providing insights into temporal and spatial retinal variations.