Accuracy of intraocular lens power prediction by using six different formulas
- VernacularTitle:六种人工晶状体屈光度数计算公式的准确性比较
- Author:
Yan JIANG
;
Yuying SHI
;
Wenli YANG
- Publication Type:Journal Article
- Keywords:
phacoemulsification;
intraocular lens
- From:
Ophthalmology in China
1994;0(02):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To compare the accuracy of intraocular lens(IOL)power calculations by using 6 formulas(SRK-T,Haigis,Binkhorst-Ⅱ,Hoffer Q,Holladay-1,SRK-Ⅱ)in different axial lengths of the eye,in order to improve the accuracy of predicating IOL powers for patients after cataract surgery.Design Retrospective comparative clinical analysis.Participants 169 patients(169 eyes)with age-related cataract underwent regular phacoemulsification and posterior chamber IOL implantation.Methods 169 eyes with cataract were divided into five groups according to the axial lengths:AXL≤22mm,22mm28.4mm.The axial lengths and keratometry of the 169 eyes were measured with A-mode ultrasound before operation,and the actual postoperative refraction was measured with the methods of computer and retinoscopy optometry when patients could gain best corrected visual acuity one month after surgery or later.Inputting the axial lengths,keratometry and IOL powers into A-mode ultrasound,the predicted postoperative refraction was calculated with SRK-T,Haigis,Binkhorst-Ⅱ,Hoffer Q,Holladay-1,SRK-Ⅱ formulas,and the differences of predicted and actual postoperative refractions in different axial lengths were compared.Main Outcome Measures The absolute value with the differences of the predicted and actual postoperative refractions,i.e.absolute predicted errors.Results(1)Comparing the difference of predicted and actual postoperative refraction,there was no statistical significance between the five formulas in the groups of axial length(AXL)≤22mm,22mm28.4mm,but the average absolute predicted error of Haigis and SRK-T formulas is significantly smaller than SRK-Ⅱand Binkhorst-Ⅱ formulas.Conclusions In existing sample size,there was no obvious influence on postoperative refraction when using other five formulas except Binkhorst-Ⅱ.But in the extremely long AXL group,Haigis and SRK-T formulas have some ascendancy over the other formulas.
