Authors’ Response: Comparison of intraocular lens power prediction accuracy of formulas in American Society of Cataract and Refractive Surgery post-refractive surgery calculator in eyes with prior radial keratotomy

Dear Editor, We have read the comments in the “letter to editor” written regarding our article and thank the authors for their inputs and queries. We would like to bring forward a few points in response to the same. Firstly, we used the nonparametric Friedman test for statistical analysis in our study.[1] Yes, other statistical methods are available and could be used, but it is unlikely that they would change the findings of our study. Generalized estimating equations have a role when adjusting for the use of bilateral eyes that tend to have a similar outcome and are suited for larger sample-sized studies. Using this method to compensate for the relatively low number of post-RK eyes with varying RK incisions was not considered appropriate, because it was likely to result in loss of valuable data and probable underestimation of significance. Also, our study protocol was centered around the American Society of Cataract and Refractive Surgery post-refractive calculator for eyes with prior radial keratotomy for myopia. Hence, we used only the formulas that are displayed in the calculator, and other formulas were not part of our study. Currently, we use only the ASCRS calculator for the workup of post-RK patients. We acknowledge the publication regarding the biases mentioned,[2] and it is definitely a concept that we would like to explore further. However, as it was published after the submission of our paper (on December 31, 2022), it was not included as a part of our publication. The prediction error estimation is performed by multiple methods and is still a topic of debate. Financial support and sponsorship: Nil. Conflicts of interest: There are no conflicts of interest.