Abstract
Methods: :
Twenty healthy adult volunteers participated in this study (Mean age ± SD: 21.7 ± 1.5 yrs). The OPs were recorded with a DTL-type electrode after pupillary dilation and a 30 minute period of retinal dark-adaptation. Stimuli consisted of dim white flashes presented in a Ganzfeld bowl. The OPs were recorded at 8 different points in time before, during and after breathing 30 minutes of pure oxygen (O2). The arterial blood O2 saturation (SaO2), end-tidal CO2 (EtCO2), respiratory rate (RR), pulse rate (PR) and blood pressure (BP) were monitored throughout the experiment.
Results: :
The amplitude of the OPs did not vary significantly across test conditions except for OP3 (p< 0.05), which increased up to 30% with systemic hyperoxia and was still elevated by the end of the experiment. The implicit times of the OPs did not vary significantly throughout the experiment (p> 0.05). The SaO2 and RR increased (p= 0.0001), the EtCO2 and PR decreased (p= 0.0001), whereas the BP was not altered (p> 0.05) during O2 breathing.
Conclusions: :
This study provides further evidence indicating that the neural generators of OP3 display a unique enhanced response to increased systemic hyperoxia in the young healthy adult. Further studies looking at OP3 are still needed to determine if this unique behavior could serve as in index of altered oxygen level and retinal function in health or disease.
Keywords: electroretinography: clinical • oxygen • retina