Diagnostic accuracy of different keratoconus detection indices of pentacam in paediatric eyes

Abstract

Objective No diagnostic gold standard for keratoconus in children and adolescents exists. Our objective was investigating the diagnostic accuracy of various indices for keratoconus (KC) detection in paediatric eyes. Methods All retrievable data of significance from 432 normal right paediatric eyes and 48 eyes of paediatric KC and forme fruste KC (FFKC), imaged by use of a rotating Scheimpflug camera (Oculyzer II, Pentacam HR) between December 2013 and October 2018 at Watany Eye Hospitals, Cairo, Egypt, including Scheimpflug images data, were collected. The area under the receiver operating characteristic curve (AUROC) was calculated for different indices in this retrospective descriptive study. Results All 36 tested indices showed discriminative power differentiating KC and FFKC from normal corneas (AUROC P-value <0.05), except AC volume, AC angle, and horizontal decentrations of the steepest and thinnest points. The 32 indices showed variable degrees of diagnostic accuracy. The highest AUROC was that of the corneal assessment index from the relational thickness and other OCULUS values (CAIRO 8). Only 8 indices showed non-inferiority to it, namely, Ambrosio’s relational thickness maximum (ART max) and avg, the pachymetric progression index maximum (PPI max) and avg, the back elevation from the best-fit toric ellipsoid (BE BFTE), the KC index (KI), the topographic KC indices (TKC), and the index of height decentration (IHD) (P > 0.05). Conclusions The 8 most useful rotating Scheimpflug imaging indices for KC detection in paediatric eyes are CAIRO 8 followed by ART max and avg, PPI max and avg, BE BFTE, KI, TKC, and IHD.

Scheimpflug-Derived Keratometric, Pachymetric and Pachymetric Progression Indices in the Diagnosis of Keratoconus: A Systematic Review and Meta-Analysis

“…The normal group comprised normal eyes of patients evaluated for refractive surgery. Rotating Scheimpflug imaging system Nil Hashem et al, 2022 18 Egypt Out-patients 480 13.5, 15.3 The study group comprised normal paediatric right eyes while the study group comprised eyes of paediatric keratoconus Rotating Scheimpflug Camera (Oculyzer II, Pentacam HR) The Science and Innovation Funding in cooperation with The Egyptian Knowledge Bank Bae et al, 2014 19 South Korea Out-patients 48 28, 25.08 Patients who had advanced KC in one eye and a normal fellow eye were considered unilateral KC. The normal control patients were candidates for refractive surgery with clinically normal corneas.…”

“…Figure18 Bubble plots of meta-regression for the effect of publication year on K1, K2, Kmax and CCT (A-D respectively.…”

Corneal topographic indices of scheimpflug camera in type 2 diabetic and non-diabetic elderly populations

“…Comparisons between the diabetic and non-diabetic groups showed that only PPIavg and PPImax were statistically higher in the diabetic versus non-diabetic subjects. Tomography-derived pachymetric indices such as PPI values are better for the differential diagnosis of normal from abnormal corneas compared to single-point corneal thickness measurements [ 16 , 17 ]. Several studies compared central corneal thickness between the diabetic and non-diabetic groups [ 18 ].…”

Machine learning analysis with the comprehensive index of corneal tomographic and biomechanical parameters in detecting pediatric subclinical keratoconus

“…As KC in young patients is reported to be more likely to progress than in adults, the sensitivity index and cutoff values of parameters in pediatric patients is different than in adult patients. (Hashem et al, 2022;Neustein and Lenhart, 2022). The machine learning analysis, analyzing a large number of variables, found that the Pentacam is one of the most common techniques in clinical application, as the uniqueness of this device is that it includes tomographic data, topometric data, pachymetry, elevation data, and combined data.…”

“…A retrospective observational study conducted in Egypt reported the eight most useful Pentacam indices in identifying 48 eyes of pediatric KC and SKC. (Hashem et al, 2022). Furthermore, the corneal biomechanics, which are thought to be the initiators of the disease even before notable changes in corneal morphology, were not evaluated in the above study.…”