Biometry with Partial Coherence Interferometry and Ultrasonography in High Myopes

Chung, J K; Choe, Chul Myong; You, Yong Sung; Lee, Sung Jin

Abstract

PURPOSE: To compare the refractive outcome of clear lens extraction employing partial coherence interferometry data with that of applanation ultrasonography.
METHODS
Thirty eyes of 17 patients with axial length greater than 26 mm who underwent clear lens extraction were enrolled in this study. IOL power was measured using IOLMaster and conventional ultrasonography. Differences between predicted refraction and actual refraction were compared and analyzed according to the biometry method and IOL power calculation formulas.
RESULTS
Axial length according to IOLMaster measurement (29.23+/-1.40 mm) was significantly longer than that measured by ultrasonography (28.68+/-1.32 mm) (p=0.000). The difference between actual and predicted refraction was 0.75+/-0.40 diopter by SRK/T with IOLMaster and 0.44+/-0.52 diopter by SRK/T with A-scan. The standard errors of the two measurement methods were 0.08 and 0.10, respectively. Eighty-five percent and one hundred percent of patients were within 1 diopter, as measured by SRK/T with IOLMaster and with A-scan, respectively.
CONCLUSIONS
The use of the IOLMaster with the SRK/T formula may be an accurate method of IOL calculation in cases of high myopes, if surgeon factors are corrected for.