Repeatability Of Corneo-Scleral Topography In Keratoconus
Published 2026 - 44th Congress of the ESCRS
Reference: POCOR404 | Type: Poster | DOI: 10.82333/5n85-wh28
Authors: Prof. Dr Andres Vasquez Quintero* 1 , Mrs Dieuwke van Ooik 2 , Dr Korine van Dijk 2 , Mr Andres Uribe 3 , Mrs Renske de Zwaef 3 , Mrs Lieselot Burggraeve 4 , Prof. Dr Carina Koppen 5
1Ghent University,Ghent,Belgium;Azalea Vision,Ghent,Belgium, 2Visser Contactlenzen,Nijmegen,Netherlands, 3Azalea Vision,Ghent,Belgium, 4Azalea Vision,Ghent,Belgium;Ghent University Hospital,Ghent,Belgium, 5Antwerp University Hospital,Antwerp,Belgium
Purpose
The KC-DATA trial aims to gather high-resolution corneo-scleral topography and wavefront aberrometry data from patients with corneal ectatic disorders. This data is critical for refining algorithms used to design personalized, freeform scleral contact lenses. These smart lenses are intended to house active electronics to enhance visual quality for keratoconus patients. The specific purpose of this analysis is to evaluate the spatial repeatability of corneo-scleral measurements across varying stages of disease severity using the Oculus Pentacam AXL Wave, ensuring a robust foundation for automated lens customization.
Setting
This multicenter data collection study was conducted at the University Hospital Antwerp (UZA), Belgium, and Visser Contactlenzen Brunssum, the Netherlands. The protocol was reviewed and approved by the respective institutional Ethics Committees and national competent authorities.
Methods
52 subjects (94 eyes) with keratoconus were enrolled. Corneo-scleral topography was performed using the Pentacam AXL Wave. Each eye underwent three repeated scans to assess repeatability. Subjects were stratified by Belin/Ambrósio clinical severity (Grade 0–4). Spatial repeatability was quantified using pixel-wise Intraclass Correlation Coefficients (ICC 2,1) on a grid with 0.5 mm resolution. Total measurable scleral surface area was analyzed to determine if disease severity impacted scan coverage. Statistical analysis was performed in R, utilizing the Per Protocol analysis set for primary outcomes.
Results
The cohort was 67.3% male with a mean age of 35.8 ± 14.4 years. 54.3% of eyes were classified as Grade 4 (Severe). The device demonstrated "Excellent" spatial repeatability (ICC > 0.90) across all levels of severity, including the central and mid-peripheral zones. Advanced ectasia (Grade 4) did not significantly degrade scan coverage, maintaining a mean equivalent diameter of 18.6 ± 0.9 mm, comparable to normal eyes. Common software alerts like "3D Model Deviation" were frequent in Grade 4 eyes due to extreme morphology but did not compromise global repeatability. A significant moderate-to-strong correlation was found between Kmax and BCVA (OD: r=0.48, OS: r=0.56, p<0.001).
Conclusions
The Oculus Pentacam AXL Wave is a robust tool for mapping the corneo-scleral geometry of keratoconus patients, regardless of disease stage. The high spatial repeatability (ICC > 0.90) and consistent scan coverage (avg. ~18.5 mm diameter) confirm the device's viability for large-diameter scleral lens customization. These findings validate the use of a single high-quality scan for extracting the geometry required for freeform lens design, provided no iris-based alignment errors occur. This reliable data pipeline supports the future integration of electronics into smart scleral lenses to provide superior visual rehabilitation for patients with irregular corneas.