Total keratometry for intraocular lens power calculation in eyes with previous myopic corneal refractive surgery

The purpose of this study was to evaluate the refractive outcomes of cataract surgery in eyes with previous myopic corneal refractive surgery using total keratometry (TK) and the Barrett True-K No History method for intraocular lens (IOL) power calculation.

Four clinical centers in India.

Ambispective case series.

All eyes had previously undergone either myopic photorefractive keratectomy (PRK) or laser in situ keratomileusis (LASIK) and underwent cataract surgery with monofocal IOL implantation. Before surgery, TK and standard keratometry (K) were measured with the IOLMaster 700 (Carl Zeiss Meditec AG, Jena, Germany), while simulated keratometry (Sim K) was measured with the Pentacam HR (Oculus). IOL power calculations were performed with the Barrett True-K No History with TK. Prediction errors (PEs) and median absolute errors (MAEs) were calculated.

A total of 35 patients were included. The MAE and mean PE with the Barrett True-K No History with TK (0.42 ± 0.34 D, 0.01 ± 0.54 D) were more accurate compared to the Barrett True-K No History with K (0.47 ± 0.43 D, 0.11 ± 0.63 D), Barrett True-K No History with Sim K (0.68 ± 0.79 D, -0.30 ± 1.00 D), Haigis with TK (0.70 ± 0.57 D, -0.56 ± 0.71 D), and Haigis L with K (0.59 ± 0.45 D; 0.20 ± 0.72 D), all P < 0.05.

In eyes with previous myopic PRK and LASIK, the combination of the Barrett True-K No History with TK from the IOLMaster 700 allowed for improved refractive outcomes, with the highest percentage of eyes achieving the target refraction.