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ABCD progression display for keratoconus progression: a sensitivity-specificity study



To evaluate the sensitivity and specificity of the ABCD progression display for keratoconus progression.


Data was collected from patients that underwent at least two Pentacam assessments 6 months apart. Sensitivity and specificity were calculated for the ABCD progression display. Progression was defined by criterion 1: change in two ABCD parameters above 80% confidence interval (CI) or criterion 2: change in one ABCD parameter above 95%CI. Receiver operating characteristic analysis compared the area under the curve (AUC) of all ABCD parameter combinations.


Thirty eyes were evaluated over a median time of 10.3 months. Progression by criterion 1 resulted in a sensitivity of 61.9% and specificity of 88.9%. Progression by criterion 2 resulted in higher sensitivity (80.9%) and specificity (100%). Pairwise comparisons of the ROC curves show that the AUC achieved by criterion 2 was significantly higher than criterion 1 (0.905 vs. 0.754, p = 0.0332). Evaluation of all ABCD combinations with a significant change of 80% or 95% CI did not show superiority over criterion 1 or 2 regarding progression detection. The D parameter had a very low AUC (0.5–0.556).


The ABCD progression display can assess keratoconus progression with high sensitivity and specificity, thus assisting the patients’ decision-making process. The D parameter did not contribute to the sensitivity or specificity of this classification.

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Fig. 1: Comparing ROC curves between Belin’s criterion 1 and criterion 2.

Data availability

The datasets generated during and/or analyzed during the current study are not publicly available due to containing information that could compromise patient privacy but are available from the corresponding author on reasonable request.


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Authors and Affiliations



AA collected data, conducted the statistical analysis, and wrote the draft of the article. RY collected data, updated reference lists and reviewed the paper. AT validated the statistical analysis. UE, YN, EL, and IB interpreted the results and reviewed the paper.

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Correspondence to Asaf Achiron.

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Achiron, A., Yavnieli, R., Tiosano, A. et al. ABCD progression display for keratoconus progression: a sensitivity-specificity study. Eye (2022).

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