Evening CRAE
SDB RFM/CPAP, hypoxia, CRAE, SDB
HYPOXIA, EYE
Group mean values for evening CRAE in our Main Group were ~12% smaller than reported for the younger Inter99 Eye study non-sleep cohort [In our multivariate Base Models, Main Group evening CRAE values were predicted by a combination of “fixed at the time of study” individual characteristics (age, ethnicity, height, smoking history) and one “physiological variable” (systolic BP; see It should be emphasised that our Base Model for evening CRAE explains only ~18% of the total variance, leaving the vast majority of the between subject variance unexplained. This is not unusual, with published multivariate models developed using larger cohorts explaining only 8.2 to 31.7% of the variance [In the Main Group, no SDB variable correlated with CRAE, adding SDB variables to the Base Model did not improve the predictive power of the model and no SDB variable emerged as a predictor. However, in the more severe SDB RFM/CPAP Group, when AHI and AHI category were added to the Base Model, the model now explained ~25% of the variance and both AHI and AHI category emerged as predictors for a slightly larger evening CRAE. This may be a consequence of hypoxia, as AHI is a surrogate for intermittent hypoxia, and chronic hypoxia has been demonstrated in animal models to result in retinal angiogenesis [A unique feature of the present study is the measurement of both evening and morning retinal vessel diameters across a night where sleep was monitored and SDB quantitatively assessed. Multivariate models identified change in diastolic BP as a negative predictor but no SDB variable was identified as a predictor for overnight change in CRAE.