Original Article
Accuracy comparison of total keratometry and standard keratometry in intraocular lens power calculations for post-corneal refractive surgery cataract patients
Wang Xiaochen, Su Wenjie, Ge Jiajia, Huang Yusen
Published 2024-08-11
Cite as Chin J Ophthalmol, 2024, 60(8): 689-694. DOI: 10.3760/cma.j.cn112142-20240301-00090
Abstract
ObjectiveTo compare the accuracy of intraocular lens (IOL) power calculations using total keratometry (TK) versus standard keratometry (K) in post-corneal refractive surgery cataract patients.
MethodsThis retrospective case series study included 30 patients (36 eyes) with a history of laser corneal refractive surgery who underwent cataract extraction and IOL implantation at Qingdao Eye Hospital, Affiliated to Shandong First Medical University, from September 2022 to December 2023. The cohort comprised 16 males and 14 females, with an average age of (53.6±8.1) years. IOL power was calculated using the K-based Haigis-L and Barrett True-K formulas, as well as the TK-based Haigis and Barrett Universal Ⅱ formulas. Postoperative objective refraction was performed to obtain the actual refractive status of the operated eyes. The refractive prediction error (RPE) was defined as the difference between the actual spherical equivalent and the predicted refraction. The absolute value of the RPE was taken as the refractive absolute error (RAE). Differences in errors calculated by the four formulas were compared.
ResultsTK showed good consistency with K, with TK being on average 0.50 D lower than K. Analysis of variance revealed statistically significant differences in RPE among the four formulas (P<0.001). The RPE for the TK-based Haigis formula was (0.17±0.09) D, and for the Barrett Universal Ⅱ formula, it was (0.21±0.11) D, both significantly better than the K-based Haigis-L formula (-0.61±0.12) D and Barrett True-K formula (-0.57±0.11) D (all P<0.001). The percentage of eyes with postoperative RPE<±1.00 D was higher for the TK-based Haigis (92%, 33 eyes) and Barrett Universal Ⅱ (86%, 31 eyes) formulas compared to the TK-based Barrett True-K (75%, 27 eyes) and Haigis-L formulas (67%, 24 eyes), with statistically significant differences (P<0.05).
ConclusionsCompared with K, TK improves the accuracy of IOL power calculation in post-corneal refractive surgery patients. Both the TK-based Barrett Universal Ⅱ and Haigis formulas demonstrate high accuracy.
Key words:
Biometry; Lenses, intraocular; Forecasting; Refractive surgical procedures; Corneal surgery, laser
Contributor Information
Wang Xiaochen
Eye Institute of Shandong First Medical University, State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Qingdao 266071, China
Su Wenjie
Eye Institute of Shandong First Medical University, State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Qingdao 266071, China
Ge Jiajia
Eye Institute of Shandong First Medical University, State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Qingdao 266071, China
Huang Yusen
Eye Institute of Shandong First Medical University, State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Qingdao 266071, China
