Optimizing Iol Power Calculation In Cataract Patients With Prior Radial Keratotomy And Lasik

This study aims to evaluate the accuracy of intraocular lens (IOL) power calculation formulas in cataract patients with a history of both radial keratotomy (RK) and LASIK, identifying the most reliable methods for predicting postoperative refractive outcomes in this complex patient population.

Terciary Care Center

The study included 10 eyes from five patients with a history of both RK and LASIK who underwent cataract surgery. Preoperative biometric and corneal topographic measurements were recorded, and postoperative subjective refraction was analyzed. Nine IOL power calculation formulas were assessed: Barrett True-K, Shammas, True-K, Haigis L, Holladay 1, Pearl-DGS, Kane, Hoffer Post RFX, and EVO Post RFX. Accuracy was evaluated based on mean arithmetic error (MAE) and mean absolute error (MAE), and paired t-tests were used to determine statistical differences in predictive performance among the formulas.

Holladay 1 demonstrated the highest accuracy, with a mean absolute error of 0.50 ± 0.67, while Haigis L exhibited the least variance in prediction, with a variance of 0.89. Paired comparisons showed a statistically significant difference between Holladay 1 and the Pearl-DGS calculator (p = 0.021), as well as a highly significant difference between the Pearl-DGS calculator and EVO Post RFX (p < 0.0001). No significant differences were found between Barrett True-K and Kane (p = 1.000) or between Barrett True-K and Holladay 1 (p = 0.051). Correlation analysis indicated strong agreement among multiple formulas, with Pearson’s correlation values exceeding 0.7 in most cases.

The findings suggest that Holladay 1 provides the most precise IOL power calculations for patients with a history of RK and LASIK. Strong correlations were observed among several formulas, indicating that multiple approaches can yield reliable results. However, variations in predictive accuracy highlight the importance of formula selection based on individual patient characteristics. Further studies with larger sample sizes are warranted to validate these findings and refine predictive models for post-refractive cataract patients.