Local neuroretinal function during acute hypoxia in healthy older people

Abstract

Purpose: To measure acute mild systemic hypoxia on neuroretinal function in two different age groups. Methods: The slow-flash paradigm of the multifocal electroretinogram (mfERG) was measured in two different oxygenation levels. Twelve participants of two age groups (28±4 and 55±5 years) breathed room air (normoxia) or 12% oxygen (hypoxia). Results: During normoxia (SaO2 = 98%) there was a significant effect between the younger and older participants on the mfERG positive waveform components (N1P1 amplitudes and P1- implicit times) (p < 0.001). Hypoxia (SaO2 = 90%) significantly decreased N1P1 response density amplitudes in the central retinal field in both groups, with a larger effect in the older group (p < 0.001). There was no significant change in function of the cellular generators of oscillatory potentials (OPs). Conclusion: Our results extend recent findings by showing a greater effect of hypoxia effect on ON- and OFF-bipolar cell function in healthy older persons compared to younger persons, but no effect on OPs during moderate acute hypoxia in either age group.