Scheimpflug And Oct Technologies In Corneal Assessment Post-Cxl: A Comprehensive Analysis
Published 2026 - 44th Congress of the ESCRS
Reference: POCOR401 | Type: Free paper | DOI: 10.82333/kfyp-zm06
Authors: Dr Emilio A. Torres-Netto* 1 , Mr Léonard Kollros 2 , Dr Mark Hillen 1 , Dr Michalina L. Depczyńska 1 , Mrs Nikki L. Hafezi 1 , Prof. Dr Farhad Hafezi 1
1Ophthalmology,ELZA Institute,Zurich,Switzerland, 2Optometry,ELZA Institute,Zurich,Switzerland
Purpose
To reassess the efficacy and reliability of Scheimpflug and OCT imaging technologies in evaluating corneal structural changes post-corneal cross-linking (CXL), addressing potential discrepancies in diagnosing corneal haze and keratoconus progression.
Setting
This study was conducted at the ELZA Institute, Dietikon, Switzerland.
Methods
This retrospective study analyzed 6-month post-CXL outcomes in 52 eyes of patients who underwent standard (5.4 J/cm²) and high-fluence (10 J/cm²) CXL using Scheimpflug and combined Placido disk/OCT imaging (Pentacam, Oculus, and MS-39, CSO Italia, respectively) to assess corneal tomographies and other related parameters. Comparative analysis focused on discrepancies in corneal densitometry and topography measurements, aiming to identify the most accurate diagnostic tool for post-CXL corneal assessment.
Results
Our findings suggest that both technologies are highly important for examining the post-CXL cornea for signs of ectasia progression. However, at 6 months after CXL, Scheimpflug imaging overestimated progression when compared to combined Placido disk/OCT imaging. The discordance between the two technologies appeared to be greater when higher fluence irradiation protocols were used. This discordance appears to be related to corneal haze, which falsifies the height data calculated from the Scheimpflug image, but shows less impact on OCT/Placido-generated data. At 12 months post-CXL, the Belin Progression display partially compensated for the false positive signals generated by Scheimpflug imaging.
Conclusions
Obtaining comprehensive corneal topographies/tomographies at patients' post-CXL follow-up visits is the centrepiece of determining the CXL treatment efficacy, but it appears that when corneal haze is present, Scheimpflug imaging-based devices may give a more pessimistic assessment of the cornea than Placido disk/OCT imaging-based instruments. Within this context, it is worth noting that higher fluence accelerated CXL protocols – particularly epi-off protocols – can be associated with higher rates of corneal haze. It may be the case that the 6-month success rates of CXL, as determined by OCT/Placido disk imaging-based instruments, may be higher than previously reported.