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. 2020 Oct 5:7:49.
doi: 10.1186/s40662-020-00215-1. eCollection 2020.

Tomography-based definition of keratoconus for Down syndrome patients

Soheila Asgari  1 , Shiva Mehravaran  2 , Mohammadreza Aghamirsalim  3 , Hassan Hashemi  1
Affiliations

Tomography-based definition of keratoconus for Down syndrome patients

Soheila Asgari et al. Eye Vis (Lond). .

Abstract

Background: To assess the diagnostic ability of Pentacam HR (Oculus Optikgeräte, GmbH, Wetzlar, Germany) tomographic indices in discriminating keratoconus (KC) and KC suspect (KCS) in 10- to 30-year-old patients with Down syndrome (DS).

Methods: In this study, DS patients were enrolled through special needs schools, the National Down Syndrome Society, and relevant non-profit organizations. Diagnoses were made independently by two experienced specialists. Forty Pentacam indices related to corneal thickness, volume, density, keratometry, power, shape, aberration, and elevation were extracted. For each index, the accuracy for KC and KCS diagnosis was evaluated using discriminant analysis and the area under receiver operating characteristic curve (AUROC). From each enrolled case, data from only one eye was entered in the analyses.

Results: Analyses were performed on data from 25 KC, 46 KCS, and 154 non-ectatic DS eyes. The best discriminants for KC were anterior higher order aberrations (HOA) (cutoff > 0.643, AUROC = 0.879), posterior vertical coma (cutoff > 0.0702 μm, AUROC = 0.875), anterior vertical coma (cutoff > 0.4124 μm, AUROC = 0.868), and total HOA (cutoff > 0.608, AUROC = 0.867). The difference between AUROCs were not statistically significant (all P > 0.05). For KCS, the best discriminants were minimum corneal thickness (cutoff ≤ 480.0 μm, AUROC = 0.775), corneal volume (cutoff ≤ 55.3 μm, AUROC = 0.727) and Belin Ambrosio display-total deviation (BAD-D) (cutoff > 2.23, AUROC = 0.718) with no significant difference between AUROCs (all P > 0.05).

Conclusions: In this sample of DS patients, best KC discriminators were HOA and coma which showed good diagnostic ability. For KCS, best predictors were minimum corneal thickness, corneal volume, and BAD-D with relatively good diagnostic ability. Defining a new set of KC diagnostic criteria for DS patients is suggested.

Keywords: Diagnostic criteria; Discriminant analysis; Down syndrome; Keratoconus; Tomography.

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Conflict of interest statement

Competing interestsThe authors declare that they have no competing interests.

Figures

Fig. 1
Fig. 1
Distribution of discriminant scores in the keratoconus and non-ectatic groups of Down syndrome cases in this study
Fig. 2
Fig. 2
Distribution of discriminant scores in the keratoconus suspect and non-ectatic groups of Down syndrome cases in this study
See this image and copyright information in PMC

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