Posters

Repeatability and reliability of measurements obtained by the Sirius analyzers in keratoconic eyes

Poster Details

First Author: U.Tunc TURKEY

Co Author(s):    Y. Yıldırım   Y. Akbas                 

Abstract Details

Purpose:

To investigate the repeatability and reliability of corneal curvature, thickness, volume and keratoconus screening indexes in keratoconus patients using combined Scheimpflug-Placido disc anterior segment analysis system.

Setting:

Prospective study.

Methods:

In this study, 3 consecutive measurements were performed by the same observer using Scheimpflug- Placido disc anterior segment analysis device in keratoconus patients. Apical curvature, SimK and corneal volume as well as the keratoconus screening indexes including thinnest corneal thickness, symmetry index, keratoconus vertex and Baiocchi-Calossi-Versaci index were recorded. Keratoconic eyes were divided into 4 stages using the Amsler-Krumeich classification. Repeatability was evaluated using within subject standard deviation, precision, repeatability index and coefficient of variation (CoV); reliability was evaluated by intraclass correlation coefficient.

Results:

One hundred thirty one eyes of 80 keratoconus patients were included in the study. At presentation, 28 eyes (21%) were classified as stage 1 keratoconus; 39 eyes (30%) were classified as stage 2 keratoconus, 19 eyes (14%) were classified as stage 3 keratoconus, and 45 eyes (34%) were classified as stage 4 keratoconus. Repeatability was good (CoV<3,9%) and reliability was excellent (intraclass correlation coefficient >0.950) for all indices in the study.

Conclusions:

The measurements in keratoconus patients using combined Scheimpflug-Placido disc anterior segment analysis system were highly repeatable and reliable. However, it should be considered that the measurement variability may be slightly higher in severe keratoconus.

Financial Disclosure:

None