The Clinical Efficacy of the Haigis Formula Using A-Scan Contact Ultrasound Biometry

ABSTRACT

PURPOSE: To investigate the accuracy of the Haigis formula compared to other formulas using contact ultrasound biometry. METHODS: 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(R). Patients were divided into three groups based on AXL; Group I (AXL or = 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(R) measurements. Mean absolute error (MAE) were analyzed at one month after surgery using the various IOL formulas. RESULTS: 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(R), the Haigis formula showed 0.16 D higher error that decreased when the AXL was close to the normal range. CONCLUSIONS: 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.