The comparative study of IOL Master and A ultrasound combined with corneal topography measurement for IOL power / 中国医师杂志

ABSTRACT

Objective To investigate the difference of IOL Master and A-ultrasound combined with corneal topography meas-urement in intraocular lens ( IOL) power calculation .Methods A total of 84 eyes of 60 cataract patients received phacoemulsification and intraocular lens implantation surgery were selected in Xiangya Hospital from March 2010 to September 2011.There were 57 eyes of 42 age-related cataract patients and 27 eyes of 18 complicated cataract patients .The patients were divided into IOL Master group and A ultrasound combined with corneal topography measurement group .Before surgery , in IOL Master group , axial length ( AL) and corneal curvature were measured with IOL Master , IOL power was calculated according to the Haigis , SRK/T formula and so on.At the same time the axial length ( AL) and corneal curvature were measured with A ultrasound combined with corneal topography respectively and IOL power was calculated by SRK/Ⅱ formula.In A ultrasound combined with corneal topography measurement group , axial length ( AL) and corneal curvature were measured with A ultrasound combined with corneal topography respectively , IOL power was calculat-ed according to the SRK/Ⅱformula.3 months postoperatively , all the patients were conducted refractive outcome and calculating mean absolute refractive error(MAE).Finally the data were analysed.Results ⑴In IOL Master group, before operation there was no sig-nificant difference in mean axial length between IOL Master and A-ultrasound measurement ( P >0.05 ) , while in the patients with AL>26 mm the axial length was (28.53 ±0.57)mm and (29.42 ±0.64)mm using IOL Master and A-ultrasound measurement respec-tively ( P <0.05).The mean corneal curvature was (42.12 ±0.31)D and (43.09 ±0.27)D using IOL Master and corneal topogra-phy measurement respectively ( P <0.01).The mean IOL power were (17.06 ±0.48)D and (16.37 ±0.56)D in IOL Master group and A ultrasound combined with corneal topography measurement group respectively ( P <0.05 ) .⑵3 months postoperatively , the MAE was (0.07 ±1.05)D and (0.16 ±0.81)D in IOL Master group and A-ultrasound combined with corneal topography measure-ment group( P <0.05) respectively.Conclusions In cataract patients with normal axial length , IOL Master and A-ultrasound com-bined with corneal topography have high consistency for axial length measurement and IOL power calculation .But in cataract patients with high myopia , IOL Master is more accurate for axial length measurement and IOL power calculation compared to A -ultrasound com-bined with corneal topography .