Pupil Sizes in Different Japanese Age Groups and the Implications for Intraocular Lens Choice

Purpose: To observe pupil sizes with near and distance vision under different lighting conditions in different Japanese age groups.

Setting: Department of Ophthalmology, Tokyo Dental College Suidobashi Hospital, Tokyo, Japan.

Methods: Using an open view-type infrared video pupillometer, the horizontal and vertical pupil sizes were measured prospectively with subjects gazing at 30 cm or 3 m targets under photopic (illumination 500 lux) and mesopic (illumination 5 lux) conditions. The results were analyzed by age, and the benefits with various multifocal IOLs were evaluated.

Results: The study comprised 140 eyes (70 subjects; 14 to 94 years). The mean +/- standard deviations of photopic vertical pupil sizes when gazing far/near decreased from 3.77 +/- 0.23/3.50 +/- 0.33 mm (<20 years) to 2.20 +/- 0.30/1.95 +/- 0.20 mm (over 80 years), with pupil sizes stabilizing after 60 years. The mesopic vertical pupil sizes when gazing far/near decreased from 6.35 +/- 0.11/6.27 +/- 0.14 mm (<20 years) to 3.42 +/- 0.30/3.21 +/- 0.28 mm (over 80 years). The pupil sizes decreased with age until 60 years and stabilized (1-way analysis of variance, P<.05). Fewer than 50% of subjects over 60 years of age had pupil sizes conducive to the near zone of refractive multifocal intraocular lenses.

Conclusion: Photopic and scotopic pupil sizes decreased with age up to 60 years. The pupil was smaller when gazing at a near target than previously reported.