ESCRS - FP16.12 - Corneal Refractive Surgery Screening: International, Multimodal Imaging, Inter-Expert Agreement Study Highlights The Need For Expert Consensus

Corneal Refractive Surgery Screening: International, Multimodal Imaging, Inter-Expert Agreement Study Highlights The Need For Expert Consensus

Published 2024 - 42nd Congress of the ESCRS

Reference: FP16.12 | Type: Free paper | DOI: 10.82333/9sdt-fw03

Authors: Niklas Mohr* 1 , Martin Dirisamer 1 , Jorge Alio del Barrio 2 , Alain Saad 3 , Stefan Kassumeh 1 , Wolfgang Mayer 1 , Siegfried Priglinger 1 , Nikolaus Luft 1

1Department of Ophthalmology,University Hospital, LMU Munich,Munich,Germany, 2Division of Ophthalmology,School of Medicine, Universidad Miguel Hernández,Alicante,Spain;Cornea, Cataract and Refractive Surgery Department,VISSUM Corporation,Alicante,Spain, 3Department of Ophthalmology,Rothschild Foundation Hospital,Paris,France

Purpose

To evaluate the inter-surgeon agreement in ectasia screening for refractive surgery using Scheimpflug tomography with and without epithelial thickness mapping.  

Setting

Retrospective multicenter study

Methods

Four highly experienced refractive surgeons (MD, JA, AS, NL) retrospectively evaluated 103 cases with normal (n=44), ectasia suspicious (n=44) and true keratoconic (n=15) corneal tomographic findings regarding their suitability for keratorefractive surgery based on clinical refractive data, Scheimpflug tomography and epithelial thickness mapping in a masked fashion. To compare the interrater agreement, Fleiss Kappa of the surgeons’ answers were calculated. Additionally, the impact of the different imaging modalities to their individual decision making was ranked by the surgeons.

Results

In a total of 18.7% cases, the decision whether a candidate was eligible or not changed by incorporating epithelial thickness mapping into refractive surgery screening. A total of 12.9% were “screened in” 5.7% were “screened out”, respectively. Interrater agreement regarding eligibility was moderate before (Fleiss K=.462) and after (Fleiss K=.430) incorporating thickness mapping and was remarkably low in the borderline group (Fleiss K=.136 and .124). Regarding specific epithelial thickness patterns (e.g. apical thinning), Fleiss Kappa ranged between -.78 and .351 (poor to fair agreement). Surgeons ranked topography, followed by BAD display and epithelial thickness mapping as the most influential imaging modalities for their decision making.

Conclusions

Adding epithelial thickness mapping to ectasia screening tends to cause “screening in” of refractive surgery candidates. However, there is poor inter-expert agreement in the assessment and interpretation of epithelial thickness maps, particularly in borderline cases. A global consensus on the assessment of epithelial thickness mapping and its role in ectasia screening is warranted.