Statistical analyses
The results were expressed as median (25–75thpercentiles) since most indices followed a non-normal distribution.
Comparisons between the visits were performed using Wilcoxon signed-rank
test. Correlations were evaluated using Pearson’s correlation
coefficient. A p value <0.05 was deemed significant. All
statistical analyses were performed with StatView 5.0 software (SAS
Institute, Cary, NC, United States).