How Does Retinal Arterial Vessel Diameter Dilation Change with Length of Chromatic Flicker Application?
Kotliar K. E.1, Vilser W.2, Lanzl I. M.1
1Department of Ophthalmology, Technical University, Munich; 2Biomedical Engineering, Technical University, Ilmenau
Purpose: The exposition of the retina to flickering light is followed by retinal vessel dilation. A standardization of the properties of flickering light so far has not been undertaken in different laboratories. Flickering light can be applied using different wavelengths. The vessel response to green-blue and green-red flickering light with different exposure time was examined in our study.
Method: In 10 young, healthy volunteers the Retinal Vessel Analyzer (RVA) was applied to asses retinal arterial diameters. A baseline measurement was performed for one minute. Then a flicker light, which was integrated into the observing camera light path, switching between the colors red (600 - 720 nm) - green (530 - 570 nm) and blue (430 - 520 nm) - green (530 - 570 nm) with a flicker frequency of 12 Hz was applied for 10, 20, 30 or 60 seconds. All experiments were repeated three times. The experiment using 30 sec stimulation was repeated after one week with the same volunteers.
Results: With both tested chromatic flickering lights a prompt vessel dilation of retinal arteries in comparison to baseline could be determined in all volunteers. On average with red-green flicker this amounted to 2.5%Zurück | Back