THE PUPILLARY LIGHT REFLEX .1. AGE-DEPENDENT AND AGE-INDEPENDENT PARAMETERS IN NORMAL SUBJECTS

A hundred and three normal subjects (14-75 years old) were examined with a modified infrared TV videopupillometer that had previously been developed. Maximal pupillary diameter (p < 0.00001), pupillary diameter in percent of iris diameter (p < 0.00001), maximal pupillary area (p < 0.00001), latency time of the light reflex (p < 0.00001), maximal contraction velocity (p < 0.00002), contraction velocity at 1 s (p < 0.00001) and dilatation velocity at 6 s (p < 0.0001) arc strongly age dependent. A statistical formula is given to allow the calculation of the exact percentile for every parameter. Parameters which are age independent if they are expressed in percent of the maximal pupillary area are contraction velocity at 1 s (r = 0.042, p = 0.68) and dilatation velocity at 6 s (r = 0.150, p = 0.13). They can be used if age-matched study groups are not available. Furthermore, it is shown that most parameters of the pupillary light reflex correlate significantly with each other. The highest correlations are found with the maximal pupillary area. Differences between sexes are not evident. It is thought that this infrared videopupillometry and the given data base are useful for further clinical studies to investigate the autonomic nervous system.