Research progress on the measurement of anterior segment parameter and calculation formula of IOL power of abnormal eye axis / 国际眼科杂志(Guoji Yanke Zazhi)

@#The good effect of refractive cataract surgery depends on a variety of factors, mainly including accuratebiometrics before surgery and accurate calculation of intraocular lens(IOL)power. The accuracy of intraocular biometrics with abnormal eyes axis before surgery is lower. Moreover, compared with the normal eyes axis, the error of postoperative refractive state prediction is larger, which brings great challenges to obtaining the best postoperative visual quality. Recently, new optical biometrics have been used clinically, and individualized IOL power calculation formulas have been developed and applied, which makes the choice of intraocular lens power more accurate. This article reviews the latest research progress on the measurement of eye parameters and the selection of IOL power calculation formula in patients with abnormal axial cataract in the past 3a, in order to provide reference for clinical application.

Accuracy of Three Intraocular Lens-power Formulas in Predicting Refractive Outcomes in Different Intraocular Lenses

PURPOSE: To compare the accuracy of different power-calculation formulas in predicting the postoperative refraction of three-piece and one-piece intraocular lenses (IOL). METHODS: We retrospectively reviewed the medical records of 74 eyes (62 patients) that had undergone cataract surgery involving implantation of one of two IOLs―the SENSAR® AAB00 1-Piece Acrylic IOL (44 eyes), or the Hoya® VA60BB 3-Piece Acrylic IOL (30 eyes)―between October 2014 and March 2015. Axial length was measured using an optical low-coherence refractometry (Lenstar®), and biometry was then calculated by the pre-installed Lenstar program, which used the SRK/II, Sanders-Retzlaff-Kraff/Theoretical (SRK/T), and Hoffer Q formulas. Mean absolute error (MAE) and mean numeric error (MNE) were measured 1 day, 1 week, 1 month, and 2 months after surgery. RESULTS: Using the SRK/T and Hoffer Q formulas, the one-piece IOL group differed significantly from the three-piece IOL group in terms of the MNE obtained 1 month and 2 months after surgery. Across all formulas and time points, there were no significant differences between the groups in terms of MAE. CONCLUSIONS: There was no significant difference between the different power-calculation formulas. Starting 1 month after surgery, the three-piece IOL group showed myopic postoperative refraction compared to the predictive spherical equivalent using the SRK/T and Hoffer Q formulas.