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Response to: WaveLight® Contoura topography-guided planning: contribution of anterior corneal higher-order aberrations and posterior corneal astigmatism to manifest refractive astigmatism

Authors Motwani M

Received 17 August 2018

Accepted for publication 20 August 2018

Published 11 October 2018 Volume 2018:12 Pages 2001—2004


Checked for plagiarism Yes

Editor who approved publication: Dr Scott Fraser

Manoj Motwani

Motwani Lasik Institute, San Diego, CA, USA
I would like to thank Wallerstein et al1 for his thoughtful research letter, but I do have some issue with the analysis. The paper references only Part 1 of the LYRA Protocol series, and not the other two parts. Part 3 provides the data for treatment with Contoura-measured astigmatism using the LYRA Protocol (termed anterior corneal astigmatism [ACA]). The concept of anterior corneal higher-order aberrations (CHOA) modifying the manifest refractive astigmatism (RA) was illustrated in an ovalization form to demonstrate why the LYRA Protocol works. These interactions are three-dimensional (3D) in nature, and we are demonstrating with 2D CHOA maps from Contoura. These maps are impacted by user/technical error, and also by epithe¬lial compensation of the CHOA, adding a layer of inaccuracy in these comparisons. In fact, the concept of epithelial compensation affecting the ability to measure and treat CHOA is not part of any current refractive system, Contoura, Ray tracing, etc. The static Gullstrand model has mainly been used, ignoring the fact that epithelial compensation causes variability.
View the original paper by Wallerstein and colleagues. 

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