Posters

Inter-day corneal thickness variation in healthy corneas measured with Pentacam: comparison with an ultrasound pachymetry

Poster Details

First Author: R.Canones SPAIN

Co Author(s):    S. Rodrigo-Rey   J. Paz   J. Abad   P. Drake   I. Rodriguez-Perez   G. Bolivar     

Abstract Details

Purpose:

To assess the reproducibility of central corneal thickness (CCT) inter-day measurements obtained by a high resolution rotating Scheimflug Camera (Pentacam, Oculus) and to compare the measured values with those obtained using ultrasound pachymetry (USP) (OcuScan).

Setting:

Department of Ophthalmology of Príncipe de Asturias University Hospital, Alcalá de Henares, Madrid, Spain, Clinica Novovision, Madrid, Spain.

Methods:

CCT was measured in sixty eyes of 30 healthy subjects at different corneal locations with Pentacam system (thinnest-CT, apical-CT, central pupil-CT and midperipheral CT measured at the distance of 2mm of the corneal apex). The measurements were repeated at the same hour in three different days. Afterwards, six consecutive measurements were obtained with USP and averaged. Only central CT (CCT) measures from USP were obtained. The within-subject standard deviation (Sw) and coefficient of variation (CoV) were calculated to compare repeatability between the two different pachymetry devices.

Results:

The Mean CCT values obtained with Pentacam were 541,30±36.14μm for central cornea spots, 537,70±36.58μm, 543,93±35.69μm, 542,25±35.90μm for thinnest-CT, apical-CT and central pupil-CT respectively. Mean CCT registered with USP was 531,60±39.74μm. Good reproducibility was found for both devices, with a CoV of 1.10% for the Pentacam central points, 1.02%, 0.95% and 0.96% to thinnest-CT, apical-CT and central pupil-CT respectively. CoV of the USP CCT was 2.54%. Statistically significant differences were found in reproducibility between Pentacam and USP measurements (p<0.05).

Conclusions:

In the assessment of normal corneas, CCT measurements provided by Pentacam demonstrated a high level of repeatability and a higher precision than that achieved by USP. Thus, in healthy corneas Pentacam would be a more reliable method than the USP assessing CCT.

Financial Disclosure:

None