The influence of tilt, decentration, and pupil size on the higher-order aberration profile of aspheric intraocular lenses.

PURPOSE

To characterize the influence of tilt angle, decentration, and pupil size on the higher-order aberration (HOA) profile of 3 aspheric intraocular lenses (IOLs) using a physical model eye.

DESIGN

A 4-factor (model, pupil, angle, decentration) in vitro experimental design comparing 3 aspheric IOLs using a physical model eye.

METHODS

Measurements of HOA were obtained using the Zywave aberrometer (Bausch & Lomb, Rochester, NY) and a purpose-built physical model eye. The following IOLs were assessed with various levels and combinations of pupil diameter, decentration, and tilt angle: the AcrySof IQ SN60WF aspheric (Alcon, Hünenberg, Switzerland), Technis ZA9003 aspheric (Advanced Medical Optics, Santa Ana, CA), and Adapt Advanced Optics (Bausch & Lomb). Fifteen Zernike modes were compared using multivariate analysis of variance, canonical discrimination, and regression analysis. Four identical IOLs of each IOL model were assessed at all possible combinations of 3 pupil sizes, 4 levels of decentration, and 4 tilt angles.

MAIN OUTCOME MEASURES

Individual HOA from z200 to z550.

RESULTS

Pupil size, decentration, model, and tilt angle all had statically significant effects on the HOA profile. Pupil size contributed most to observed total variability (54.9%), followed by decentration (22.7%), then model (16.6%), and finally tilt angle (5.7%). All factors demonstrated significant interaction terms with respect to HOA. Intraocular lenses with increased aspheric properties inherent in the design of the optic were more sensitive to decentration and change in pupil size.

CONCLUSIONS

The 3 IOL models demonstrated significant differences in HOAs in response to changes in pupil size, decentration, and tilt angle. All IOL models assessed in this study demonstrated minimal HOA at small pupil diameters. The IOL models with lower, or an absence of, negative spherical aberration were most robust to displacement with increased decentration and tilt angle.