Intraoperative Aberrometry Versus Preoperative Biometry for IOL Power Selection After Radial Keratotomy: A Prospective Study

Abstract

PURPOSE: To compare the accuracy of Optiwave Refractive Analysis (ORA) intraoperative aberrometry (Alcon Laboratories, Inc., Fort Worth, TX) with preoperative biometry in predicting residual refractive error after cataract surgery in eyes that underwent radial keratotomy. METHODS: This was a prospective consecutive case series of patients with cataract and prior radial keratotomy. Each patient underwent a preoperative intraocular lens (IOL) power calculation using partial coherence interferometry (IOLMaster version 5; Carl Zeiss Meditec, Jena, Germany). For each eye, the Barrett True-K formula was used to select an IOL targeting emmetropia. Residual refractive error was predicted preoperatively using the SRK/T, Hoffer Q, Haigis, and Holladay formulas 1 and 2, and the ORA intraoperatively. Between 8 and 12 weeks after cataract extraction with IOL implantation, the postoperative refraction was compared with the preoperative and intraoperative predictions. RESULTS: The study comprised 52 eyes of 34 patients. The median absolute errors associated with each method were as follows: Barrett True-K formula (0.34), ORA aberrometer (0.53), and SRK/T (0.54), Hoffer Q (0.51), Haigis (0.54), SRK/T (0.57), and Holladay formulas 1 and 2 (0.44) ( P = .08). The proportion of patients within ±0.50 diopters of the predicted error was 63.5%, 48.1%, 44.2%, 48.1%, 53.8%, 36.5%, and 57.7%, respectively ( P = .03). No statistically significant difference was observed in the number of eyes with hyperopic outcomes ( P = .68). CONCLUSIONS: In eyes with prior radial keratotomy surgery, the ORA aberrometer performance was similar to the Barrett True-K formula and all of the other established formulas, with no significant difference between median absolute error and mean absolute error. The Barrett True-K formula produced significantly more eyes within ±0.50 diopters than the SRK/T, Hoffer Q, and Holladay 1 formulas. [ J Refract Surg. 2019;35(10):656–661.]

Comparison of refractive prediction for intraoperative aberrometry and Barrett True K no history formula in cataract surgery patients with prior radial keratotomy

“…2013; Curado et al. 2019). However, in our study 19.2% of patients still had a refractive prediction error > 1.0D, and depending on the method used, 4.3%‐8.5% of patients (IA and Barrett TKNH, respectively) had a refractive prediction error > 2.0D.…”

“…Previous studies have shown that for RK eyes, Barrett TKNH has a significantly smaller median absolute refraction error and a greater percentage of eyes within ± 0.50 dioptres compared with other commonly used formulas not optimized for prior refractive surgery, including SKR/T, Hoffer Q and Holladay 1 (Curado et al. 2019). For non‐RK myopic laser refractive surgery eyes, Barrett TKNH outperformed several formulas that are optimized for prior refractive surgery, including Adjusted Atlas, Modified Masket, Wang–Koch–Maloney, Shammas and Haigis‐L (Abulafia et al.…”

“…However, to date, there have been limited data comparing IA to preoperative biometry in eyes with previous RK (Curado et al. 2019). Also, there are no studies that have compared these techniques between patients with lower (<8 cuts) versus higher (≥8 cuts) numbers of RK cuts.…”

Refractive Accuracy of Barrett True-K vs Intraoperative Aberrometry for IOL Power Calculation in Post-Corneal Refractive Surgery Eyes

“…[2][3][4] In post-refractive surgery eyes, the percentage of patients achieving those results range from 40% to 69%. [5][6][7][8] Over the past decade, several formulas were developed to improve the precision of IOL power calculation in post-corneal refractive surgery eyes, including the Haigis-L, 9 Shammas, 10 Masket, 11 and Barrett True-K formulas. 12 Several studies have reported on the superiority of the Barrett formulas (Barrett Universal II and Barrett True-K) compared to other preoperative calculation methods in predicting IOL power in eyes with or without previous refractive surgery.…”

Time Utilization and Refractive Prediction Enhancement Associated with Intraoperative Aberrometry Use During Cataract Surgery

“…Comparison with newer formulas has shown that IA is equal or worse than the Barrett Universal II or Hill-RBF. 17,18 IA has been reported to be similar to Barrett True-K for eyes with history of radial keratotomy, 19 no different than Optovue, Haigis-L, or Masket regression formulas for eyes with prior laser vision correction, 20 and in one study better than Haigis-L and Shammas and surgeon's choice of formulas in eyes with prior laser vision correction. 21 A similar study to ours using only newer formulas, such as the Barrett Universal II formula, Kane formula, or Hill-RBF in comparison to IA would be of interest, in particular for eyes with extremes of axial length for which these newer formulas may be an improvement over older formulas.…”