Accuracy of Partial Coherence Interferometry in Intraocular Lens Power Calculation

ABSTRACT

PURPOSE: To evaluate the accuracy and the influencing factors of partial coherence interferometry in intraocular lens (IOL) power calculation for cataract surgery. METHODS: In 86 eyes of 69 patients who had undergone cataract surgery, we measured axial length using both IOLMaster and contact type ultrasonography, calculated the target refraction with SRK II formula and compared the result with the measured value after operation. We also evaluated the factors influencing the accuracy of the power calculation such as age, sex, type of cataract, severity of nucleosclerosis, corneal power, and preoperative refraction. RESULTS: In IOLMaster and contact type ultrasonography, the mean axial lengths were 23.70 +/- 1.27 mm and 23.55 +/- 1.28 mm (p<0.01), and the mean absolute errors (MAE) of refraction were 0.53 +/- 0.26D and 0.66 +/- 0.39D (p<0.01) respectively. The eyes of longer axial length showed larger MAE than those of shorter axial length (p=0.02). CONCLUSIONS: Partial coherence interferometry was more accurate than contact type ultrasonography in IOL power calculation. The factor associated with the accuracy of partial coherence interferometry was the axial length.