- 1Singapore National Eye Centre, Singapore, Singapore
- 2Singapore Eye Research Institute, Singapore, Singapore
- 3Corneal Service and Clinical Research Unit, Vasan Eye Care Hospital Group, Saidapet, Chennai, India
- Correspondence to Donald Tan, Singapore Eye Research Institute, 11 Third Hospital Avenue, #05-00 SNEC Building, Singapore 168751, Singapore;
- Accepted 10 April 2011
- Published Online First 10 May 2011
We thank the editors and Dr Gerald McGwin Jr for their interest and comments with regard to the statistical methodology used in our paper.1 Upon further statistical consultations, we concur that the study would indeed be best considered as a retrospective cohort study, as opposed to a case–control study. Our original intent was to perform frequency matching in comparing deep anterior lamellar keratoplasty (DALK) with penetrating keratoplasty (PK) groups, but this was only partially achievable, as previously stated in our paper, and as a result age, race and diagnosis were demographically profiled rather than identically matched.
To re-evaluate the fundamental accuracy of our results, we therefore proceeded to perform ANCOVA analysis of refractive results and logistic …