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

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.

It is time for a Turning Point in Keratoconus

“…2 Increasingly sophisticated diagnoses, intelligent CT scanners, machine learning and artificial intelligence are at the service of ophthalmologists who are passionate about the subject and of patients for higher, refined and early diagnoses. 3 This has made keratoconus a subspecialty of modern ophthalmology and poses ever new and exciting challenges in the clinical, diagnostic, and therapeutic fields. There was a need for an international society dedicated to this disease, distinct and separate, but which is open to dialogue with the most important international societies of refractive and anterior segment eye surgery.…”

“…2 Increasingly sophisticated diagnoses, intelligent CT scanners, machine learning and artificial intelligence are at the service of ophthalmologists who are passionate about the subject and of patients for higher, refined and early diagnoses. 3 This has made keratoconus a subspecialty of modern ophthalmology and poses ever new and exciting challenges in the clinical, diagnostic, and therapeutic fields. There was a need for an international society dedicated to this disease, distinct and separate, but which is open to dialogue with the most important international societies of refractive and anterior segment eye surgery.Thus, the IKS (International Keratoconus Society) was finally born, the home of ophthalmologists who deal with keratoconus and of all those who want to dedicate themselves to this fascinating sector of ophthalmology.Such an important Society could not fail to have an equally important scientific Journal, and we have the honor of having the International Journal of Keratoconus and Ectatic Corneal Diseases (IJKECD) as our official IKS scientific Journal.…”

“…There was a need for an international society dedicated to this disease, distinct and separate, but which is open to dialogue with the most important international societies of refractive and anterior segment eye surgery.Thus, the IKS (International Keratoconus Society) was finally born, the home of ophthalmologists who deal with keratoconus and of all those who want to dedicate themselves to this fascinating sector of ophthalmology.Such an important Society could not fail to have an equally important scientific Journal, and we have the honor of having the International Journal of Keratoconus and Ectatic Corneal Diseases (IJKECD) as our official IKS scientific Journal. 3 I cannot hide a certain emotion, because it was precisely in this Journal that the M nomogram 4,5 for the standardized treatment of individualized crosslinking of ectatic corneas of all thicknesses was born, as awarded in the ESCRS Congress in 2019 in Paris with the "Joseph Colin Prize" for innovating therapies in the field of Keratoconus. 4,5 The "M nomogram" allows safe and effective setting of CXL parameters based on thickness minimum preoperative corneal membrane, also allowing the standardized treatment of thin and ultrathin ectatic corneas with a minimum thickness between 250 and 400 µm, keeping the fluence standardized in the Dresden Protocol constant (5.4 J/cm 2 ).…”