Evaluation of posterior corneal surface and total corneal keratometry employing multiple anterior segment imaging devices: a comparative study

Session Details

Session Title: Presented Poster Session: Imaging Anterior Segment

Session Date/Time: Monday 07/09/2015 | 15:00-16:30

Paper Time: 15:40

Venue: Poster Village: Pod 4

First Author: : G.Asimellis GREECE

Co Author(s): :    A. Kanellopoulos              

Abstract Details

Purpose:

To evaluate posterior corneal surface and total corneal keratometry measurements (steep, flat, and related astigmatism magnitude and axis) employing a novel corneal Color LED Reflection topographer (CLR) in comparison to Scheimpflug imaging and Anterior-segment OCT (AS-OCT).

Setting:

LaserVision.gr Clinical and Research Institute

Methods:

Posterior-surface and total corneal keratometry measurements (flat K1, steep K2, and related astigmatism magnitude and axis) was investigated in 50 eyes via the following devices: A, CLR the Cassini, i-Optics, the Hague, The Netherlands, B, Scheimpflug, the Pentacam, Oculus Optikgeräte GmbH, Wetzlar, Germany, and (c) a Fourier-domain OCT, the Avanti, Optovue, Fremont, CA,. All devices report anterior, posterior, and total corneal keratometry. Two groups were formed, Group-A, healthy (n=25) and Group-B, eyes subjected to LASIK (n=25). Correlations between the different device measurements was assessed via, correlation coefficient, Bland-Altman plot analysis. Limits of Agreement (LoA) were also employed.

Results:

In group-A, correlation coefficient between the Cassini and the Pentacam ranged between 0.94 and 0.97 for K1, K2, and astigmatism magnitude, and between the Cassini and the AS-OCT between 0.93 and 0.97 for the average of K1 and K2. In group-B, correlation between the Cassini and the Pentacam ranged between 0.90 and 0.95 for K1, K2, and astigmatism. Between the Cassini and the AS-OCT ranged from 0.91-to-0.94 for the average of K1 and K2. Axis differences between the Cassini and the Pentacam range between 5 to 15° (group-A and group-B, respectively). Larger deviations were noted in lower amounts of astigmatism.

Conclusions:

The corneal Color LED Reflection topographer appears to report increased posterior and total keratometry values compared to the other two devices. Astigmatism appears to be affected by the posterior surface measurements.

Financial Interest:

One of the authors travel has been funded, fully or partially, by a company producing, developing or supplying the product or procedure presented