Heidelberg CAIRS

Standardized Reporting Templates for CAIRS Transplantation Studies

Corneal allogeneic intrastromal ring segment (CAIRS) keratoplasty has emerged as a promising treatment for keratoconus and other corneal ectatic disorders. Since its first description by Soosan Jacob in 2018, numerous studies have demonstrated visual, refractive, topographic and aberrometric improvements following the procedure. At the same time, considerable variation has developed in graft preparation techniques, surgical approaches, nomograms, and outcome assessment methods.

This heterogeneity makes it challenging to compare results across studies, evaluate the impact of specific surgical modifications, and combine evidence in systematic reviews and meta-analyses. In addition, important procedural details may be reported inconsistently, and outcome measures may differ in both the parameters presented and the methods used to obtain them.

To address these challenges, we developed a standardized reporting framework for CAIRS transplantation. Inspired by the reporting system that has become the reference standard in refractive surgery, these templates provide a consistent approach to describing the intervention and presenting postoperative outcomes. Their use aims to improve transparency, facilitate comparisons between studies, and support the continued refinement of CAIRS treatment planning, surgical techniques, and clinical outcomes.

The templates described below accompany our publication on standardized reporting of CAIRS results and are freely available for researchers, clinicians, and journal authors.

Available Downloads

1. Intervention Characteristics Table

This template provides a standardized framework for documenting the CAIRS procedure. It includes fields for reporting:

• Graft type and preparation technique
• CAIRS geometry
• Surgical and intraoperative characteristics
• Postoperative OCT-based measurements
• Measurement conventions and reporting methodology

Consistent reporting of these variables enables meaningful comparisons between studies and facilitates the evaluation of how differences in graft characteristics, implantation geometry, and surgical technique influence clinical outcomes.

2. Standardized Outcome Graphs

This Excel spreadsheet automatically generates standardized figures for reporting the efficacy and safety of CAIRS transplantation. The template is adapted from the Standard Graphs for Reporting Outcomes after Refractive Surgery, originally developed by Dan Reinstein and Timothy Archer, and has been modified specifically for CAIRS.

The spreadsheet generates standardized graphs for:

• Corrected distance visual acuity (CDVA)
• Uncorrected distance visual acuity (UDVA)
• Changes in CDVA and UDVA
• Manifest refractive astigmatism
• Manifest refractive spherical equivalent
• Spherical equivalent over time
• Higher-order aberrations (HOAs)
• Mean, flat, and steep keratometry
• Maximum keratometric flattening

Important note: We recommend assessing maximum keratometric flattening using preoperative-to-postoperative difference maps rather than relying solely on changes in Kmax, as postoperative shifts in Kmax location may underestimate the true flattening effect of CAIRS transplantation.

Citation

If you use these templates in your research, please cite the accompanying publication which describes the proposed reporting standard:

Publication

These templates are intended to promote standardized reporting, facilitate comparison between studies, improve the quality of evidence synthesis, and support further refinement of CAIRS transplantation techniques and treatment planning.