New study reveals best IOL power calculation formulas for post-LASIK/PRK eyes
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Key Takeaways
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Barrett True-KT Formula was found to be the most accurate for IOL power calculations post-LASIK/PRK with the lowest MAE and MedAE.
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Potvin-Hill Formula was found to be best for eyes with a low B/F ratio and flat PK, showing superior accuracy in these cases.
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The Barrett True-KT formula is the most accurate for calculating intraocular lens (IOL) power in patients who have had myopic LASIK or PRK surgery, according to a study.
However, for eyes with a low back-to-front corneal radius ratio (B/F ratio) and a flat posterior keratometry (PK), the Potvin-Hill formula may provide better results.
This retrospective case series included 101 patients with 132 eyes affected by cataracts following LASIK/PRK surgery. Researchers analyzed the performance of various IOL power calculation formulas by measuring the mean prediction error (PE), mean absolute prediction error (MAE), median absolute error (MedAE), and the percentage of eyes achieving a prediction error within ±0.25, ±0.50, and ±1.00 diopters (D).
The Barrett True K-TK formula demonstrated the highest accuracy overall, with the lowest MAE (0.59 D) and MedAE (0.48 D), and the highest percentage of eyes within ±0.50 D of the predicted value (54.55%). Conversely, in cases where the B/F ratio was 0.70 or lower and PK was -5.70 D or more, the Potvin-Hill formula outperformed others, showing the lowest MAE ranging from 0.46 to 0.67 D.
Reference
Zheng Y, Zhang J, Han X, et al. Effect of Posterior Keratometry and Corneal Radius Ratio on the Accuracy of Intraocular Lens Formulas After Myopic LASIK/PRK. J Refract Surg. 2024;40(9):e635-e644. doi: 10.3928/1081597X-20240718-01. Epub 2024 Sep 1. PMID: 39254245.
