Normal Foveal Thickness Clinical Trial
Official title:
Agreement in Foveal Thickness Measurements Between Spectralis® and Stratus® Optical Coherence Tomography
Optical coherence tomography (OCT) is a well-established and safe technique that offers the
possibility of visualizing retinal structure and measuring retinal thickness. Time-domain
(TD)OCT is considered the "gold standard" technique for retinal thickness measurements.
Spectral-domain (SD) OCT has to face the gold standard technique prior to obtain scientific
and clinical consensus.
In our study in healthy subjects foveal thickness will be measured with both TD and SD OCT ,
and the data will be compared to evidence any difference between the two retinal
measurements techniques.
The study will be performed at the Ophthalmology Clinic of the University of Chieti-Pescara,
Italy. Forty healthy individuals will be enrolled in this study. In the same session in one
randomly selected eye of each subject three consecutive measurements of foveal thickness
will be performed using both TD OCT and FD OCT. All measurements will be obtained by the
same experienced examinator.
Time domain optical coherence tomography images will be obtained from each eye after pupil
dilation using the Stratus OCT system (version 4.1. Carl Zeiss Meditec, Dublin, CA).
Spectral domain optical coherence tomography images will be obtained using the HRA-OCT
Spectralis unit (Heidelberg Engineering GmbH, Heidelberg, Germany).
All data will be analyzed with the statistical package MedCalc® version 8.1 for Windows
(MedCalc®, Mariakerke, Belgium).
The D'Agostino-Pearson test that computes a single P-value for the combination of the
coefficients of Skewness and Kurtosis will be used to study the sample distribution.
T-test will be used to compare means between Stratus and Spectralis measurements and
orizontal and vertical measurements.
To assess agreement between Spectralis and Stratus OCT foveal measurements the Bland and
Altman plots of the agreement in foveal thickness will be used. For both orizontal and
vertical foveal measurements the ratio (Spectralis/stratus OCT foveal thickness) will be
plotted against the average of the two measurements.
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Observational Model: Cohort, Time Perspective: Cross-Sectional