Influence and predictive value of optional parameters in new-generation intraocular lens formulas.

PURPOSE

To evaluate the accuracy of various variations of new-generation multivariate intraocular lens (IOL) power calculation using the Barrett Universal II, Castrop, Emmetropia Verifying Optical 2.0, Hill-Radial Basis Function 3.0, Kane, and PEARL-DGS formulas with and without optional biometric parameters.

SETTING

Tertiary care academic medical center.

DESIGN

Retrospective case series. Single-center study.

METHODS

Inclusion of patients after uneventful cataract surgery implanting AU00T0 IOLs. Data from one eye per patient were randomly included. Eyes with a corrected distance visual acuity worse than 0.1 logMAR were excluded. IOLCON-optimized constants were used for all formulas other than the Castrop formula. The outcome measures were prediction error (PE) and absolute prediction error (absPE) for the 6 study formulas.

RESULTS

251 eyes from 251 patients were assessed. Excluding lens thickness led to statistically significant differences in absPE in several formulas. Leaving out horizontal corneal diameter did not impact absPE in several formulas. Differences in PE offset were observed between the various formula variations.

CONCLUSIONS

When using multivariate formulas with an A-constant, including certain optional parameters is vital for optimal refractive results. Formula variations excluding certain biometric parameters need specifically optimized constants and do not perform similarly when using the constant of the respective formula using all parameters.