Pupil Diameter in Patients With Multifocal Intraocular Lenses

Abstract

PURPOSE: To evaluate the distribution of pupil size in patients implanted with multifocal intraocular lenses (IOLs) and to assess the variations according to age. METHODS: A total of 168 eyes that had implantation of several multifocal IOLs and were measured at the 3-month follow-up visit were included in the analysis. The Keratograph 5M (Oculus Optikgeräte) was used to measure the photopic and mesopic pupil size, as well as the average between both (average pupil size). Eyes were stratified in four groups by age: 50 years or younger, 51 to 60 years, 61 to 70 years, and older than 70 years. RESULTS: Considering the total sample, 84.5% and 95.8% of eyes had a photopic pupil size of 3 and 3.5 mm or less, respectively. The mesopic pupil size was greater than 4.5 mm in 39.3% and greater than 5 mm in 16.7% of eyes. The average pupil size was 3.5 and 4 mm or less in 54.2% and 85.1% of eyes, respectively. Mesopic pupil size resulted in a steeper decrease with age than photopic pupil size: 0.028 versus 0.015 mm/year, respectively. Statistically significant differences were found among the four age groups (P < .0005). No significant mean differences were found between multifocal IOL models for photopic pupil size, mesopic pupil size, or average pupil size (P > .05). CONCLUSIONS: Eyes implanted with multifocal IOLs had a photopic pupil size of 3.5 mm or less and mesopic pupil size of 5 mm or less. Mesopic and photopic pupil size decreased 0.28 and 0.15 mm per decade, respectively. This information can help surgeons to understand the general functioning of multifocal IOLs whose performance varies with pupil size.