The precision of novel color LED corneal analyzer Cassini in measuring corneal curvature and intraocularlens power calculation
HU Xiuli, LU Weicong, YU Xinxin
1.Dean’s Office, Wenzhou Medical University,Wenzhou 325035, China; 2.Refractive Surgery Center, the Eye Hospital of Wenzhou Medical University,Wenzhou325000, China
HU Xiuli,LU Weicong,YU Xinxin. The precision of novel color LED corneal analyzer Cassini in measuring corneal curvature and intraocularlens power calculation[J]. JOURNAL OF WEZHOU MEDICAL UNIVERSITY, 2023, 53(3): 215-220.
Abstract：Objective: To evaluate the repeatability and agreement of novel corneal analyzer Cassini in measuring corneal curvature and corneal astigmatism with IOLMaster analyzer with an analysis of the prediction of Cassini in intraocular lens power calculation. Methods: This prospective comparative study included 77 eyes of 77 patients. One experienced operator measured corneal parameters using Cassini and IOLMaster three times, including the flattest keratometry (Kf), the steepest keratometry (Ks), astigmatism (Ast), total corneal power (TCP), total corneal astigmatism (TCA) and vector analysis of astigmatism (J0, J45). The within-subject standard deviation (Sw), test-retest repeatability (TRT), and intraclass correlation coefficient (ICC) were used to assess repeatability. The agreement between Cassini and IOLMaster was achieved by Bland-Altman plots and 95% limits of agreement (LoA). The mean absolute error (MAE) of different devices and subjective refraction was calculated
after a 3-month follow-up period to analyze the precision of intraocular lens (IOL) power calculation. Results: The TRT of Kf, Ks and TCP measured by Cassini were less than 0.55 D, and the ICC values were more than0.995. The TRT and ICC were 0.47 D and 0.973 for astigmatism, respectively. The TRT and ICC of TCA were
0.75 D and 0.953, respectively. All the TRT values were less than 0.48 D and ICC values were more than 0.893 for J0, J45, J0-TCA and J45-TCA. The MAE values of Cassini and IOLMaster were both lower than 0.43 D with four different IOL calculation formulas. The percentages of eyes within ±0.25 D, ±0.50 D, ±0.75 D and ±1.00 D
of prediction error were all greater than 28%, 62%, 85% and 94% with different IOL calculation formulas. Conclusion: The novel corneal analyzer Cassini in measuring corneal curvature and corneal astigmatism had fantastic repeatability except TCA. The corneal curvature parameters revealed good agreement in Ks and Kf with IOLMaster and could be used interchangeably. In prediction error, the Cassini had similar precision with IOLMaster that makes it suitable for application inIOLcalculation
