The effect of physical effort on retinal activity in the human eye: rod and cone flicker electroretinogram studies.
BACKGROUND
The aim of our study was to assess the effect of physical exercise with increasing intensity on neuroretinal activity in healthy subjects (n = 30).


METHODS
We analysed the amplitude and implicit time of b-wave electroretinogram (ERG) responses in two experiments: (1) for a scotopic blue 10 Hz flicker stimulus (rod-mediated responses), and (2) for a photopic white 30 Hz flicker stimulus (cone-mediated responses). Using a cycloergometer, three 10-minute effort-tests with increasing intensity were performed. Each participant was assigned individual workload values (W) below the lactate threshold (40% VO(2)max), at the lactate threshold (60-65% VO(2)max) and above the lactate threshold (80% VO(2)max). Five ERG recordings were taken: (1) before, (2-4) immediately after the three subsequent efforts and (5) 1 hour after the completion of the last effort. The right eye was selected for monocular stimulation in both experiments.


RESULTS
After the first effort (40% VO(2)max), we observed an increased amplitude (p < 0.001) and decreased implicit time of the b-wave (p < 0.01) in cone-mediated responses, and no significant effects in rod-mediated responses. Despite the increase in effort intensity, the cone b-wave amplitude remained unchanged, whereas the rod b-wave amplitude significantly decreased after the subsequent efforts (p < 0.001).


CONCLUSIONS
Rod-mediated responses were more susceptible to effort-induced homeostasis disruptions than the cone-mediated responses. The application of ERGs may be used as neurophysiological criteria in defining the cardiovascular status of the physical performance.
Zwierko
Teresa
T
Department of Natural Sciences, University of Szczecin, Al. Piastów 40 b blok 6, 71-065 Szczecin, Poland. teresa.zwierko@univ.szczecin.pl
Czepita
Damian
D
Lubiński
Wojciech
W
D000328:Adult; D001824:Body Constitution; D004596:Electroretinography; D015444:Exercise / Q000502:physiology*; D006439:Hemodynamics; D006801:Humans; D019344:Lactic Acid / Q000378:metabolism; D008297:Male; D020419:Photoreceptor Cells, Vertebrate / Q000502:physiology*; D012160:Retina / Q000502:physiology; D055815:Young Adult
D019344:Lactic Acid