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Measurements of the diurnal changes of corneal radii with four different devices

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Session Details

Session Title: Corneal Biomechanics

Session Date/Time: Monday 15/09/2014 | 17:00-18:30

Paper Time: 17:12

Venue: Capital Hall A

First Author: : N.Hirnschall AUSTRIA

Co Author(s): :    S. Norrby   P. Draschl   N. Luft   S. Maedel   O. Findl  

Abstract Details


To observe the diurnal changes of the corneal radii with four different devices.


Hanusch Hospital, Vienna, Austria


This prospective study included patients and volunteers. In all patients manual keratometry (Littmann keratometer, Carl Zeiss Meditec AG, Germany), 1-ring keratometry (IOLMaster 500, Carl Zeiss Meditec AG, Germany), 2-ring keratometry (Lenstar, Haag-Streit Diagnostics, Switzerland) and topography (Atlas, Carl Zeiss Meditec AG, Germany) were performed at 4 different time points, at 7am, 12am, 5pm and 10pm, respectively.


In total, 20 patients/volunteers were included in this trial. First results showed that the diurnal changes are as large as 0.5D, or 1.0D in terms of a difference vector. The diurnal fluctuations were observed with each device to a similar extent. The entire data set was used to create a model of the diurnal changes of the cornea and the error distribution of the diurnal changes was compared with the inter-device error.


The diurnal changes of the cornea are larger than expected and should be taken into account additionally to the inter-device error.

Financial Interest:


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