Posters

Comparative evaluation of posterior corneal surface measurements employing multiple anterior segment imaging devices

Poster Details

First Author: I. Kontari 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:

The Laservision.gr Clinical and Research Institute, Athens, Greece.

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: Color-coded LED elevation topography (Cassini, i-Optics, the Hague, the Netherlands), Scheimpflug, the Pentacam, Oculus Optikgeräte GmbH, Wetzlar, Germany, 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 myopic LASIK (n=25). Correlations between the different device measurements was assessed via, correlation coefficient, and Limits of Agreement (LoA) (Bland-Altman plot analysis).

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 Disclosure:

NONE