Is Kmax a Reliable Endpoint for Evaluating Outcomes after CAIRS?
4 affiliations
- 1Department of Ophthalmology, David J. Apple International Laboratory for Ocular Pathology and International Vision Correction Research Centre (IVCRC), University of Heidelberg
- 2Department of Ophthalmology, Pallas Kliniken
- 3Queensland Eye Institute
- 4Dr Agarwal’s Eye Hospital
Abstract
In ectatic corneas such as keratoconus, maximum keratometry (Kmax) is commonly used to identify the cone apex and monitor disease severity and progression. However, with the advent of tissue-additive corneal-reshaping surgical techniques such as corneal allogeneic intrastromal ring segments (CAIRS), Kmax may no longer reliably reflect the true geometric changes of the diseased cornea. Automatically generated Kmax can be influenced by localized peripheral steepening over the implanted segments, leading to misinterpretation of the actual keratometric effect. We argue that Kmax is therefore a potentially misleading outcome parameter after CAIRS. A better capture of the true regularizing effect of CAIRS may therefore be mean keratometry, keratometry measured at the preoperative Kmax location, or maximum flattening on the difference map. Standardized reporting of these metrics is needed to enhance comparability between studies.
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BibTeX
@article{friedrich2026kmax,
title = {{Is Kmax a Reliable Endpoint for Evaluating Outcomes after CAIRS?}},
author = {Maximilian Friedrich and Dimitrios Kyroudis and David Goldblum and David J. Gunn and Soosan Jacob and Victor A. Augustin and Gerd U. Auffarth and Hyeck-Soo Son},
journal = {Ophthalmology and Therapy},
year = {2026},
month = sep,
doi = {10.1007/s40123-026-01497-9},
url = {https://doi.org/10.1007/s40123-026-01497-9},
note = {CC BY-NC},
}
RIS
TY - JOUR
TI - Is Kmax a Reliable Endpoint for Evaluating Outcomes after CAIRS?
AU - Maximilian Friedrich
AU - Dimitrios Kyroudis
AU - David Goldblum
AU - David J. Gunn
AU - Soosan Jacob
AU - Victor A. Augustin
AU - Gerd U. Auffarth
AU - Hyeck-Soo Son
PY - 2026
DA - 2026/09/01
JO - Ophthalmology and Therapy
DO - 10.1007/s40123-026-01497-9
UR - https://doi.org/10.1007/s40123-026-01497-9
AB - In ectatic corneas such as keratoconus, maximum keratometry (Kmax) is commonly used to identify the cone apex and monitor disease severity and progression. However, with the advent of tissue-additive corneal-reshaping surgical techniques such as corneal allogeneic intrastromal ring segments (CAIRS), Kmax may no longer reliably reflect the true geometric changes of the diseased cornea. Automatically generated Kmax can be influenced by localized peripheral steepening over the implanted segments, leading to misinterpretation of the actual keratometric effect. We argue that Kmax is therefore a potentially misleading outcome parameter after CAIRS. A better capture of the true regularizing effect of CAIRS may therefore be mean keratometry, keratometry measured at the preoperative Kmax location, or maximum flattening on the difference map. Standardized reporting of these metrics is needed to enhance comparability between studies.
SN - 2193-8245
SN - 2193-6528
ER -