highly significantP < 0.001
A highly significant difference ( P < 0.001) for RTL was found among the three groups, with the longest RTL in the individuals without AMD (0.91 ± 0.18), the shortest RTL in persons with late AMD (0.86 ± 0.17), and RTL in between the two groups for those with early AMD (0.88 ± 0.17) ( Fig. 1 ).