Accuracy of Wang-Koch axial length adjustment formulas in calculating postoperative refractive power in cataract patients with high myopia

Abstract

AIM: To compare the accuracy between Wang-Koch axial length adjustment formulas(SRK/TWK, Holladay ⅠWK)and SRK/T, Haigis, Holladay Ⅰ, Hoffer Q in calculating intraocular lens power of cataract patients with high myopia.METHODS: A total of 42 cataract patients with high myopia(57 eyes)were collected. All eyes underwent phacoemulsification combined with intraocular lens implantation surgery in our Hospital from September 2019 to March 2022. They were divided into two groups according to the axial length(AL): group A(27mm≤AL<30mm, 31 eyes)and group B(AL≥30mm, 26 eyes). Patients were followed up at 3mo. The actual postoperative diopter was recorded, and then the refractive mean numerical error(MNE)and mean absolute error(MAE)were calculated.RESULTS: MAE of each formulas was statistically different after surgery(P<0.01), among which the MAE of Holladay ⅠWK and SRK/TWK [0.31(0.08, 0.57), 0.34(0.17, 0.63)D] was lower than other formulas. However, there were no statistical difference between SRK/TWK, Holladay ⅠWK and SRK/T, Haigis formulas [0.61(0.27, 1.02), 0.63(0.22, 1.01)D](P>0.05). MAE were statistically different among the formulas in group A(27mm≤AL<30mm; P<0.01). The MAE of Holladay ⅠWK and SRK/TWK was lower than other formulas [0.18(0.05, 0.51), 0.28(0.16, 0.52)D], but there were no statistical difference with SRK/T and Haigis formulas [0.45(0.18, 0.65), 0.50(0.14, 0.75)D](P>0.05). In group B(AL≥30mm), the MAE of each formulas was statistically different after surgery(P<0.01), among which MAE of Holladay IWK and SRK/TWK was the lowest, followed by SRK/T and Haigis, whereas, Holladay I and Hoffer Q ranked the highest. Furthermore, there were statistical differences between MAE of SRK/TWK, Holladay ⅠWK [0.44(0.23, 0.67), 0.41(0.22, 0.66)D] and SRK/T, Haigis formulas [0.78(0.55, 1.07), 0.75(0.45, 1.25)D](all P<0.05).CONCLUSION: For cataract patients with AL ≥30mm, the Wang-Koch axial length adjustment formulas were relatively accurate in calculating diopter of intraocular lens, and had clinical application value to some extent.

Keywords

• high myopia
• cataract
• refractive error
• axial length adjustment
• intraocular lens power