Session Title: Imaging I
Session Date/Time: Friday 18/09/2015 | 08:00-09:30
Paper Time: 08:00
First Author: : K.Ghasemi Falavarjani IRAN, ISLAMIC REPUBLIC OF
Co Author(s): : A. Mehrpouya F. Amirkourjani
PURPOSE:To evaluate the effect of Topcon spectral domain optical coherence tomography (OCT) image quality on macular thickness measurements and error rate in healthy subjects and patients with clinically significant diabetic macular edema (CSME).
Eye Research Center and Eye Department, Rassoul Akram Hospital, Iran University of Medical Sciences
In this prospective comparative case series, macular thickness measurements and the rate of decentration and segmentation errors were evaluated before and after reducing image quality factor (QF). To reduce the image quality factor below 45, tetracycline eye ointment was applied on the corneal surface.
Forty eyes of 40 subjects including 18 healthy eyes and 22 eyes with CSME were included. In all, the central subfield thickness (CST) and volume measurements and the rate of grid decentration were statistically similar between the two measurements (P>0.05), however, the rate of segmentation error was statistically significantly higher after reduction of the QF (P<0.001). In both groups, the difference in CST measurements before and after reducing the image QF was not statistically significant both before and after error correction (all P>0.05). The rate of decentration error was statistically similar before and after reducing image QF in normal and CSME eyes (P=0.50, P=0.69, respectively). However, the rate of segmentation error was statistically significantly higher after reducing QF both in normal and CSME eyes (P=0.008 and P=0.004, respectively). Statistically significant correlation was found between the change in CST measurements after error correction and the change in QF in normal eyes and in eyes with CSME (P<0.001 and P=0.004, respectively). In both groups, eyes with segmentation error had higher change in image QF (both P=0.01).
Reducing image quality results in higher rate of segmentation error in normal eyes and in eyes with CSME.