Dark-adapted pupil diameter as a function of age measured with the NeurOptics pupillometer.

PURPOSE: To measure the dark-adapted pupil diameter of normal research participants in their second through ninth decades of life using the NeurOptics pupillometer (Neuroptics Inc).
METHODS: Individuals aged 18 to 80 years with no history of eye disease or injury, intraocular surgery, or use of systemic antihistamines or opiates were recruited. After 2 minutes of adaptation at 1 lux illumination, the right dark-adapted pupil diameter was measured using the NeurOptics pupillometer, with accommodation controlled by distance fixation. The NeurOptics pupillometer reported a mean dark-adapted pupil diameter and a standard deviation of the mean, which were analyzed as a function of age-decade.
RESULTS: Two-hundred sixty-three individuals participated. For participants aged 18 to 19 years (n=6), the mean dark-adapted pupil diameter was 6.85 mm (range: 5.6 to 7.5 mm); 20 to 29 years (n=66), 7.33 mm (range: 5.7 to 8.8 mm); 30 to 39 years (n=50), 6.64 mm (range: 5.3 to 8.7 mm); 40 to 49 years (n=51), 6.15 mm (range: 4.5 to 8.2 mm); 50 to 59 years (n=50), 5.77 mm (range: 4.4 to 7.2 mm); 60 to 69 years (n=30), 5.58 mm (range: 3.5 to 7.5 mm); 70 to 79 years (n=6), 5.17 mm (range: 4.6 to 6.0 mm); and 80 years (n=4), 4.85 mm (range: 4.1 to 5.3 mm). These values were consistent with studies using infrared photography. The standard deviation was >0.1 mm in 10 (3.8%) participants, all of whom were younger than 55 years.
CONCLUSIONS: The dark-adapted pupil diameter is an important clinical variable when planning refractive surgery. Surgeons can compare a patient's dark-adapted pupil diameter with the results of this population study to identify outlier measurements, which may be erroneous, and repeat testing prior to surgery. Copyright 2011, SLACK Incorporated.