Accuracy of Intraocular Lens Power Calculation Formulas in Myopic Eyes with Target Refractions of Emmetropia and Intentional Myopia

Abstract

Purpose

To compare the accuracy of the intraocular lens (IOL) power calculation formulas for predicting the postoperative refraction in eyes with a target of emmetropia or intentional myopia.

Patients and Methods

This is a retrospective study conducted at Kobe City Eye Hospital, Kobe, Japan. Fifty eyes of 50 patients with axial myopia who underwent uncomplicated phacoemulsification and single-type IOL implantation for a target of emmetropia (plano to −0.5 D) or intentional myopia (−2.0 D to −3.0 D) were selected. Preoperative ocular biometry was performed using IOLMaster700 in all eyes. Refractive prediction errors of 6 IOL formulas integrated into IOLMaster700 were compared between eyes with a target of emmetropia and intentional myopia.

Results

The mean numerical errors of SRK/T (Sanders, Retzlaff, and Kraft/theoretical), Holladay 1, Hoffer Q, and Holladay 2 significantly differed between the two groups (p < 0.001, p = 0.008, 0.02, and 0.007, respectively). The values for mean numerical errors in eyes with a target of intentional myopia were smaller, showing relatively myopic outcome, as compared with those in eyes with a target of emmetropia. In eyes with a target of emmetropia, the mean numerical errors of Holladay 1 (p < 0.001, 95% confidence interval [CI]: 0.32 to 0.63), Hoffer Q (p = 0.001, 95% CI: 0.12 to 0.42), and Barrett Universal II (p = 0.007, 95% CI: 0.06 to 0.35) were significantly different from zero (hyperopic trend). Furthermore, in eyes with a target of intentional myopia, the mean numerical error of SRK/T (p = 0.001, 95% CI: −0.61 to −0.17) and Holladay 2 (p = 0.023, 95% CI: −0.43 to −0.04) were significantly different from zero (myopic trend).

Conclusion

In patients with axial myopia, some IOL formulas may show a myopic trend in the refractive outcome when targeting intentional myopia as compared to emmetropia.

Keywords:

• cataract surgery
• postoperative refraction
• intentional myopia
• axial myopia
• IOLMaster700

Abbreviations

AL, axial length; IOL, intraocular lens; SRK/T, Sanders, Retzlaff, and Kraft/theoretical.

Data Sharing Statement

All data included in this study are available from the corresponding author upon reasonable request.

Ethics Approval and Informed Consent

This retrospective study was performed in accordance with the Declaration of Helsinki and was approved by the Medical Ethics Committee of the Kobe City Medical Center General Hospital (Kobe, Japan). We applied an opt-out arrangement to obtain the informed consent for this observational study, which involved the analysis of medical records. The confidentiality of patient data was maintained.

Acknowledgments

We thank Mika Watanabe (Kobe City Eye Hospital) for collecting data.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

The authors declare no conflicts of interest.

Additional information

Funding

There is no funding to report.