Posters

Keratoconus indices in monitoring keratoconus

Poster Details

First Author: V.Ramani MALAYSIA

Co Author(s):    Z. Azari   P. Nilamiham   C. Arce        

Abstract Details

Purpose:

To analyse the ability of five keratoconus indices in diagnosing and monitoring keratoconus progression.

Setting:

Cornea & Refractive Surgery Centre, The Tun Hussein Onn National Eye Hospital

Methods:

168 eyes (83 keratoconus eyes and 85 normal eyes) from 84 individuals (average age: 32.40±15.95 years old). 38 individuals had normal eyes. 9 individuals had clinical keratoconus on only one eye. 37 individuals had keratoconus on both eyes. Topography was acquired using Galilei dual Scheimpflug analyzer (Ziemer Ophthalmic Systems AG, Port, Switzerland). Keratoconus Prediction Index (KPI), Anterior Axial Cone Location & Magnitude Index (CLMIaa), Inferior/Superior Value (I-S), Anterior Kranemann-Arce Indec (AKAI), and Posterior Kranemann-Arce Index (PKAI) were recorded and analysed.

Results:

There were statistically significant differences for KMax, KPI, KProb, CLMIaa, & PPK (p<0.001) between keratoconus and normal eyes, and between forme-fruste keratoconus (FFKC) and keratoconus eyes. However, there is no significant difference between FFKC and normal eyes. ROC curves showed that PKAI can differentiate between normal and keratoconus eyes with area under curve (AUC) value at 0.997. Thus is followed by AKAI (AUC=0.994), KPI (AUC=0.988), CLMIaa (AUC=0.971), and I-S (AUC=0.931). When FFKC eyes were included in the analysis all indices showed reduction in AUC, with none being able to isolate FFKC from normal eyes. AKAI and PKAI still performed better than other indices. Kruskal-Wallis analysis based on Amsler-Krumeich classification showed that AKAI can almost differentiate between different keratoconus stages, indicating an ability to denote keratoconus progression.

Conclusions:

Kranemann-Arce Indices is a robust index in keratoconus detection and is useful in monitoring keratoconus progression, although it is still not able to differentiate FFKC from normal eyes. FINANCIAL INTEREST: NONE