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.
Department of Natural Sciences, University of Szczecin, Al. Piastów 40 b blok 6, 71-065 Szczecin, Poland. teresa.zwierko@univ.szczecin.pl
Teresa
T
Zwierko
Damian
D
Czepita
Wojciech
W
Lubiński
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