Evaluating the effect of pupil dilation on spectral-domain optical coherence tomography measurements and their quality score.

Lucia Tanga,Gloria Roberti,Marco Centofanti,Francesca Berardo,Manuela Ferrazza,Gianluca Manni,Luciano Quaranta,Francesco Oddone

doi:10.1186/s12886-015-0168-y

Abstract

BackgroundSpectral-domain optical coherence tomography (SD-OCT) provides fast scan speed and high scan resolution improving its diagnostic accuracy. The purpose of this study was to evaluate if SD-OCT measurements and their quality score are influenced by pupil dilation.MethodsRetinal nerve fiber layer thickness (RNFL), ganglion cell complex (GCC) and optic nerve head (ONH) were measured in one eye of 57 glaucoma patients and 36 healthy subjects using spectral domain optical coherence tomography (SD-OCT) before and after pupil dilation. Comparisons were made between measurements and their quality score pre- and post dilation (Signal Strength Index, SSI). Overall RNFL, average GCC and ONH rim volume were considered in the analysis.ResultsNo statistically significant differences were found between pre- and post-dilation measurements in both groups (glaucoma: RNFL 80 ± 15 μm vs 80 ± 16 μm, p = 0.87; GCC 81.35 ± 13.4 μm vs 81.10 ± 13.14 μm, p = 0.92; ONH 0.05 ± 0.11 mm3 vs 0.04 ± 0.07 mm3, p = 0.74; controls RNFL 99 ± 12 μm vs 98 ± 14 μm, p = 0.70; GCC 92.12 ± 6.7 μm vs 91.54 ± 7.05 μm, p = 0.72; ONH 0.11 ± 0.1 mm3 vs 0.04 ± 0.07 mm3, p = 0.36) nor between pre- and post-dilation quality score (glaucoma SSI RNFL 54.3 ± 10.3 vs 51.7 ± 18.1, p = 0.12; SSI GCC 58 ± 9.5 vs 57 ± 8.09, p = 0.55; SSI ONH 48.5 ± 7.6 vs 46.6 ± 7.2, p = 0.16; controls SSI RNFL 57 ± 10.3 vs 54 ± 9.31, p = 0.2; SSI GCC 60.9 ± 8.1 vs 58.8 ± 7.3, p = 0.3; SSI ONH 51.5 ± 8.9 vs 50.4 ± 8.3, p = 0.59).ConclusionPupil dilation doesn’t affect SD-OCT measurements and their quality score.

Highlights

Spectral-domain optical coherence tomography (SD-Optical coherence tomography (OCT)) provides fast scan speed and high scan resolution improving its diagnostic accuracy
A glaucomatous visual field (VF) change was defined as the consistent presence of a cluster of three or more nonedge points on the pattern deviation plot with a probability of occurring in
To investigate the possible influence of the quality score on the variability between pre- and post-dilation measurements, we evaluated the correlation between this variability and the mean quality score of the two measurements, using Pearson’s correlation coefficient

Summary

Introduction

Spectral-domain optical coherence tomography (SD-OCT) provides fast scan speed and high scan resolution improving its diagnostic accuracy. The purpose of this study was to evaluate if SD-OCT measurements and their quality score are influenced by pupil dilation. The spectral-domain OCT technology (SD-OCT), has replaced the time-domain OCT (TD-OCT) providing faster scan speed, improving scan resolution and potentially increased diagnostic accuracy [9, 10]. The manufacturer of the RTVue-100 indicates the quality score limit to accept the images (the Signal Strenght Index, SSI), there is no study in literature investigating the effects of pupil dilation on it

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