Posters

Assessment of corneal thickness and aberrations using two Scheimpflug imaging systems

Poster Details

First Author: N.Martínez-Albert SPAIN

Co Author(s):    D. Monsalvez-Romin   A. Del Aguila-Carrasco   A. Dominguez-Vicent   J. Esteve-Taboada           

Abstract Details

Purpose:

To assess the agreement of corneal thickness and aberrations obtained using Pentacam HR and Galilei G4.

Setting:

University of Valencia, Valencia, Spain.

Methods:

This study included 30 eyes of 30 consecutive patients with a spherical equivalent between -1.25 to +0.75 D. Analysed parameters were thinnest and central corneal thickness, third high order aberrations and fourth order spherical aberration for a 6 mm diameter fit zone. The total root mean square was also obtained. Measurements were obtained using a single-Scheimpflug camera device (Pentacam HR) and a dual-Scheimpflug camera device (Galilei G4). Agreement was assessed by means of Bland-Altman plots.

Results:

The mean difference for the central corneal thickness between the dual and the single-camera Scheimpflug tomographer was 3.84±3.13 µm (P<0.01) and 3.93±3.53 µm for the thinnest pachymetry (P <0.01). All the aberrations evaluated were found to be statistically significantly different. The mean differences for vertical trefoil, vertical coma, horizontal coma, horizontal trefoil and spherical aberration were -0.06±0.22 µm, 0.05±0.12 µm, -0.06±0.06 µm, -0.25±0.15 µm, -0.05±0.19 µm respectively(P < 0.01). Total root mean square analysis mean difference was 0.17±0.15 D (P < 0.01).

Conclusions:

These two Scheimpflug imaging systems (Pentacam HR - Galilei G4) can be considered as interchangeable for measuring the thinnest and central corneal thickness when it comes to planning ablational refractive surgery in most cases. Contrarily, they showed poor agreement and cannot be used as interchangeable for the higher order aberrations.

Financial Disclosure:

NONE