Official ESCRS | European Society of Cataract & Refractive Surgeons


Grading keratoconus progression using a novel decision-support software tool: an agreement analysis

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Session Details

Session Title: Keratoconus

Session Date/Time: Monday 16/09/2019 | 14:00-16:00

Paper Time: 15:18

Venue: Free Paper Forum: Podium 2

First Author: : A.Rosa PORTUGAL

Co Author(s): :    M. Raimundo   C. Azenha   J. Gil   C. Tavares   P. Barbeiro                 

Abstract Details


We present a novel software tool that automatically compares tomographic parameters and evaluates keratoconus progression based on prespecified criteria. The software is able to accept parameters from most commercially available tomographers and thus is not restricted to a single device.


Centro Hospitalar e Universitário de Coimbra (Tertiary Center, University Hospital)


Two graders (one cornea specialist and one general ophthalmologist) evaluated two tomographic scans of keratoconus patients separated by more than 4 months and subjectively classified each pair in 0 – no progression, 1 – doubtful progression, 2 – clear progression. The graders were instructed to evaluate as they would in a real-life setting and no other grading guidelines were provided. The agreement between the automated software and each grader was evaluated: percentage of agreement and Cohen’s kappa (k): 0 to 0.2 (poor); 0.2 to 0.4 (fair); 0.4 to 0.6 (moderate); 0.6 to 0.8 (substantial) and 0.8 to 1.0 (almost perfect).


We included 43 eyes from 26 keratoconus patients (age 27.9±6.9 years) that underwent consecutive tomographic evaluation (7.5±2.6 months between exams) using the Oculus Pentacam HR®. The agreement between the software and a cornea specialist was very high, 92.3% [95% CI 0.88-0.97, p<0.001], with a Cohen’s K of 0.80 [95% CI 0.67-0.93, p<0.001], representing almost perfect agreement. The agreement with a general ophthalmologist was lower, 88.4% [95% CI 0.83-0.93, p<0.001], with a Cohen’s K of 0.66 [95% CI 0.51-0.83, p<0.001], representing substantial agreement.


The proposed software tool demonstrates excellent agreement with an expert grader in keratoconus progression. We believe this tool may be useful in quickly comparing critical tomographical parameters in serial exams of keratoconus patients, thus potentially improving clinical workflows. Furthermore, it may be a useful adjunct to the general ophthalmologist who may not be familiar with either tomographic examinations and/or evaluation of keratoconus progression.

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