Performances of Corneal Topography and Tomography in the Diagnosis of Subclinical and Clinical Keratoconus

Cristina Ariadna Nicula; Adriana Elena Bulboacă; Dorin Nicula; Ariadna Patricia Nicula; Karin Ursula Horvath; Sorana D Bolboacă

doi:10.3389/fmed.2022.904604

Performances of Corneal Topography and Tomography in the Diagnosis of Subclinical and Clinical Keratoconus

Front Med (Lausanne). 2022 May 26:9:904604. doi: 10.3389/fmed.2022.904604. eCollection 2022.

Authors

Cristina Ariadna Nicula^{1

2}, Adriana Elena Bulboacă³, Dorin Nicula², Ariadna Patricia Nicula⁴, Karin Ursula Horvath⁵, Sorana D Bolboacă⁶

Affiliations

¹ Department of Ophthalmology, "Iuliu Haţieganu" Medicine and Pharmacy University, Cluj-Napoca, Romania.
² Oculens Clinic, Cluj-Napoca, Romania.
³ Department of Physiopathology, "Iuliu Haţieganu" Medicine and Pharmacy University, Cluj-Napoca, Romania.
⁴ Emergency County Hospital, Târgu Mureş, Romania.
⁵ Department of Ophthalmology, "George Emil Palade" University of Medicine, Pharmacy, Sciences and Technology, Târgu Mureş, Romania.
⁶ Department of Medical Informatics and Biostatistics, "Iuliu Haţieganu" Medicine and Pharmacy University, Cluj-Napoca, Romania.

Abstract

Aim: The purpose of the study was to assess the efficacy of topographical and tomographical indices given by the Pentacam (pachymetric, tomopetric, and aberometric) in clinical and subclinical keratoconus (KCN) diagnosis.

Material and methods: In this observational analytic retrospective study, patients with abnormal findings in topography and tomography maps but with no signs on clinical examination (subclinical KCN group, sKCN), patients with clinical keratoconus (KCN group), and healthy subjects (Control group) were evaluated.

Results: The KCN group proved significantly different (p < 0.001) values of the investigated parameters than the Control group. Eleven out of 28 investigated parameters proved significantly different in the sKCN group compared to controls (p < 0.001). Two topographic measurements, namely I-S (cut-off = 1.435, a large value indicates the presence of KCN) and CCT (cut-off = 537, a small value indicates the presence of KCN), showed AUCs equal to 1 [0.999 to 1]. Six other Pentacam measurements, including Back maximum keratometry (Back Kmax) proved to be excellent parameters for case-finding and screening. In distinguishing sKCN from normal eyes, Pentacam index of vertical asymmetry (IVA), inferior-superior difference (I-S) value, thinnest point (TP), Belin Ambrosio Enhanced Ectasia Display (BAD_D) and root mean square total (RMS total) performed best.

Conclusions: In distinguishing sKCN from normal eyes, Back Kmax, IVA, I-S, and RMS total values demonstrated higher accuracy and utility. Six indices, namely ISV, IVA, KISA, PRC, RMS-HOA, and Back Kmax demonstrate excellent utility in case-finding and screening for clinical KCN.

Keywords: clinical utility; corneal tomography; corneal topography; keratoconus; subclinical keratoconus.