Posters

Intraday and interday corneal thickness variation in healthy eyes measured by Pentacam®

Poster Details

First Author: S.Rodrigo Rey SPAIN

Co Author(s):    R. Cañones-Zafra   S. Ketabi-Shadvar   P. Drake-Rodriguez   I. Rodriguez   E. Arranz-Marquez   E. Fraga     

Abstract Details

Purpose:

The purpose of this study is to determinate and characterize the magnitude of intraday and interday central corneal thickness (CCT) variation and to compare both of them, in healthy subjects and measured by oculus Pentacam® system.

Setting:

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

Methods:

In this prospective cohort study, CCT was measured in 60 healthy eyes with no ocular pathology or previous ocular surgery, with the Oculus Pentacam® Scheimpflug system. Measurements were taken in three different days: first at baseline and then 1 and 2 weeks after. In each visit, CCT was measured at three different times: 9:00am, 01:00pm and 05:00pm. CCT measurements included the thinnest CT, apical CT, central pupil CT and midperipheral CT measured at superior, inferior, nasal and temporal locations at the distance of 2mm of the corneal apex.

Results:

Mean CCT at all visits ranged from 438 to 642μm in the central corneal measurements and from 439 to 655μm in the midperipheral spots. The fixed-effect model obtained a significant decrease of the CCT throughout the day (p for trend < 0.001). In more detail, the CCT decreased -1.56μm(IC 95% -1.91, -1.22) from 9:00am to 01:00pm and -2.80μm (IC 95% -3.14, -2.45) from 9:00am to 05.00pm. This behaviour was also observed in the stratified analysis grouping the points in central or midperipheral. However, this model did not detect a significant interday CCT variation (p for trend 0.54).

Conclusions:

This data shows a very small CCT intraday variation. The CCT diurnal variation could be a reflect of the hydration and metabolism changes. Thus, an isolated measure of the CCT may be insufficient to adequately characterize it, although most probably, the diference is not clinically relevant. On the other hand, the lack of interday variation makes Pentacam® CCT more useful than the “gold standard”, contact US CCT measurement.

Financial Disclosure:

None