Purpose: To identify the most sensitive visual performance metric for evaluating the pupil-dependency of a multifocal
intraocular lens (MIOL) and to determine the pupil measurement method most correlated with such metric.
Methods: Twenty-seven right eyes implanted with a MIOL were included in the analysis. Three pupil size measurements
were obtained preoperatively and at 1 month after surgery with the Keratograph 5M system: photopic (PP), mesopic
(MP), and the average from both (AP). Pupil was also measured with a rule (RP) under the same light conditions
of postoperative visual performance measurements that included, corrected visual acuities (VA) at three distances
(far, 67 cm and 40 cm), visual acuity (VADC) and contrast sensitivity defocus curves for optotype sizes of 0.3 logMAR
(CSDC3) and 0.7 logMAR (CSDC7). Differences in visual performance were also analyzed for eyes with RP > 3 mm
(Group A) and RP ⩽ 3 mm (Group B).
Results: PP diameter decreased after surgery by 16% (p = 0.001), whereas MP (p = 0.013) and AP (p = 0.008) decreased
by 10%. The best agreement with RP was obtained for AP. Group B showed a trend to better performance than Group
A for all the included metrics (p > 0.05). From the three types of defocus curves, CSDC3 obtained generally highest
statistical power for testing differences between groups. The strongest statistically significant correlations between pupil
size and CSDC3 were obtained for RP and AP.
Conclusion: The CSDC3 was the most sensitive metric to detect MIOL pupil-dependency. PR and AP were more
correlated with CSDC3 than PP and MP.