Determining the predictive ability of keratoconus screening indices of three Scheimpflug-based devices to distinguish keratoconus from normal corneas

Session Details

Session Title: Imaging Anterior Segment

Session Date/Time: Sunday 08/10/2017 | 16:00-18:00

Paper Time: 17:10

Venue: Meeting Center Room I

First Author: : U.Choudhary INDIA

Co Author(s): :    L. Kaweri   R. Shetty                 

Abstract Details

Purpose:

To compare the predictive ability of three Scheimpflug devices in differentiating keratoconus and subclinical keratoconus from normal corneas.

Setting:

Narayana Nethralaya Eye Institute 121/C Chord Road, Rajajinagar 1st R Block, Bangalore 560010, India.

Methods:

This retrospective comparative study included 84 normal, 70 eyes with subclinical keratoconus, and 92 keratoconic eyes. In each eye, keratoconus-screening indices were evaluated using Pentacam Galilei and Sirius. Receiver operating characteristic (ROC) curves were calculated and quantified using the area under the curve (AUC).

Results:

Highest sensitivity was seen for average pachymetric progression index (RPIavg) and maximum Ambrosio relation thickness (ARTmax) (90.2% each) on Pentacam and surface asymmetry index (SAI) on Galilei (89.1%). Highest specificity was for index of height asymmetry(IHA) on pentacam (100%) and symmetry index back (Slb) and 8mm root mean square per unit area (RMS/A) back (100% each) on Sirius. To distinguish subclinical-keratoconus from normals, highest sensitivity was for keratoconus index (100%) on Pentacam and CSI on Galilei (98.6%), and the highest specificity was seen for IHA and Curvature radius (100%) on Pentacam, Slb and 8mm RMS/A back (100% each) on Sirius.

Conclusions:

Keratoconus indices measured by all three machines can effectively differentiate keratoconus from normal corneas. However, a combination of different data is required to distinguish subclinical keratoconus.

Financial Disclosure:

NONE