ABSTRACT
Background
A new keratometric routine that employs power vector management for manual keratometers is described. This study evaluates the agreement of the new proposed keratometric technique with the classical one.
Research design and methods
The applicability of a new keratometric routine was verified using Helmholtz’s and Javal’s keratometers. Results were obtained by two different and well-trained examiners over two different samples, one including 65 and the other 74 eyes, respectively. Both conventional keratometry and the newly proposed routine (named vecto-keratometry) were used in each eye to obtain the results. The clinical agreement between the methods was evaluated using Bland–Altman and Passing–Bablok analysis.
Results
For Helmholtz’s keratometer, Bland–Altman plots showed good agreement between methods for both astigmatic components being J0 = 0.04 ± 0.20 D and J45 = −0.07 ± 0.17 D. For Javal’s keratometer, Passing–Bablok regression test determined regression line for J0 difference as y0 = 1.03, confidence interval: [0.98, 1.10] and regression line for J45 difference as y45 = 0.97, confidence interval: [0.83, 1.12].
Conclusions
Vecto-keratometry provides accurate clinical results. It has been demonstrated that there are no significant differences between methods in any of the power vector astigmatic components; thus, both methods can be applied interchangeably.
Declaration of interest
The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.
Reviewers disclosure
Peer reviewers on this manuscript have no relevant financial relationships or otherwise to disclose.
Ethics approvals
Approval was obtained from the ethics committee of University of Valencia. The procedures used in this study adhere to the tenets of the Declaration of Helsinki.
Consent statement
Informed consent was obtained from all individual participants included in the study.