Diagnostic Accuracy of Corneal and Epithelial Thickness Map Parameters to Detect Keratoconus and Suspect Keratoconus

Abdelrahman Salman; Cosimo Mazzotta; Obeda Kailani; Marwan Ghabra; Rana Omran; Ashraf Armia Balamoun; Taym Darwish; Rafea Shaaban; Hala Alhaji

doi:10.1155/2023/6677932

Diagnostic Accuracy of Corneal and Epithelial Thickness Map Parameters to Detect Keratoconus and Suspect Keratoconus

J Ophthalmol. 2023 Oct 6:2023:6677932. doi: 10.1155/2023/6677932. eCollection 2023.

Authors

Abdelrahman Salman¹, Cosimo Mazzotta^{2

3

4}, Obeda Kailani⁵, Marwan Ghabra⁶, Rana Omran⁷, Ashraf Armia Balamoun^{8

9

10}, Taym Darwish¹, Rafea Shaaban¹¹, Hala Alhaji¹

Affiliations

¹ Department of Ophthalmology, Tishreen University, Latakia, Syria.
² Departmental Ophthalmology Unit, AUSL Toscana Sudest, Siena, Italy.
³ Ophthalmology School, University of Siena, Siena, Italy.
⁴ Siena International Crosslinking Centre, Siena, Italy.
⁵ Faculty of Life Sciences and Medicine, King's College London, London, UK.
⁶ Whipps Cross University Hospital, Leytonstone, London, UK.
⁷ Eye Surgical Hospital, Damascus, Syria.
⁸ Watany Eye Hospital (WEH), Cairo, Egypt.
⁹ Watany Research and Development Centre, Cario, Egypt.
¹⁰ Ashraf Armia Eye Clinic, Giza, Egypt.
¹¹ Tartous University, Tartous, Syria.

Abstract

Aim: To establish the diagnostic accuracy of corneal and epithelial thickness measurements obtained by spectral-domain optical coherence tomography (SD-OCT) in detecting keratoconus (KC) and suspect keratoconus (SKC).

Methods: This retrospective study reviewed the data of 144 eyes separated into three groups by the Sirius automated corneal classification software: normal (N) (n = 65), SKC (n = 43), and KC (n = 36). Corneal thickness (CT) and epithelial thickness (ET) in the central (0-2 mm) and paracentral (2-5 mm) zones were obtained with the Cirrus high-definition OCT. Areas under the curve (AUC) of receiver operator characteristic (ROC) curves were compared across groups to estimate their discrimination capacity.

Results: ROC curve analysis revealed excellent predictive ability for ET variables: minimum (Min) ET (0_2), minimum-maximum (Min-Max) ET (0_2), superonasal-inferotemporal (SN-IT) ET (2_5), Min-Max ET (2_5), and Min ET (2_5) to detect keratoconus (AUC > 0.9, all). Min-Max CT (0_2) was the only CT parameter with excellent ability to discriminate between KC and N eyes (AUC = 0.94; cutoff = ≤-32 μm). However, both ET and CT variables were not strong enough (AUC < 0.8, all) to differentiate between SKC and N eyes, with the highest diagnostic power for Min-Max ET (2_5) (AUC = 0.71; cutoff = ≤-9 μm) and central corneal thickness (CCT) (AUC = 0.76; cutoff = ≤533 μm).

Conclusion: These results demonstrate that OCT-derived CT and ET are able to differentiate between KC and N eyes, with a high level of certainty. However, Min-Max ET (2_5) was the parameter with the highest ability to detect suspect keratoconus.