To investigate the accuracy of the Haigis formula compared to other formulas using contact ultrasound biometry.

This study was performed on 94 patients (114 eyes) who underwent cataract surgery in our hospital. Axial length (AXL) and anterior chamber depth (ACD) were measured using both A-scan and intraocular lens (IOL) Master®. Patients were divided into three groups based on AXL; Group I (AXL < 22.5 mm), Group II (22.5 mm ≤ AXL < 25.5 mm), and Group III (AXL ≥ 25.5 mm). Before cataract surgery, predicted refraction was calculated using the Haigis, SRK/T, Hoffer Q, and Holladay 1 formulas using both A-scan and IOL Master® measurements. Mean absolute error (MAE) were analyzed at one month after surgery using the various IOL formulas.

Using contact ultrasound biometry, in Group I, MAE of Haigis was 0.80 ± 0.67 D and was significantly lower than that using SRK/T. In Group II, the Haigis MAE was 0.72 ± 0.55 D and was significantly lower than the results of all other formulas. In Group III, the Haigis MAE was 0.76 ± 1.13 D and not significantly different from the results of other formulas. Comparing MAE of A-scan to IOL Master®, the Haigis formula showed 0.16 D higher error that decreased when the AXL was close to the normal range.

Using contact ultrasound biometry, the Haigis formula provided the best predictability of postoperative refractive outcome compared to other formulas in eyes with normal axial length.