Diagnostic ability of inner macular layers to discriminate early glaucomatous eyes using vertical and horizontal B-scan posterior pole protocols.

Maria P Bambo,Noemi Güerri,Vicente Polo,Beatriz Cameo,Blanca Ferrandez,Jose M Larrosa,Luis E Pablo,Elena Garcia-Martin,Ruben Hernandez,Enrique Fuentemilla,Sanjoy Bhattacharya

doi:10.1371/journal.pone.0198397

Abstract

PurposeTo evaluate the diagnostic ability of macular ganglion cell (mGCL) and macular retinal nerve fiber (mRNFL) layers, to detect early glaucomatous eyes, using the new segmentation software of Spectralis optical coherence tomography (OCT) device (Heidelberg Engineering).MethodsA total of 83 eyes from 83 subjects were included in this observational, prospective cross-sectional study: 43 healthy controls and 40 early primary open-angle glaucoma (POAG) patients. All participants were examined using the Horizontal and Vertical Posterior Pole protocols, and the peripapillary RNFL (pRNFL) protocol of Spectralis OCT device. The new automated retinal segmentation software was applied to horizontal and vertical macular B-scans to determine mGCL and mRNFL thicknesses in each one of the 9 sectors of the Early Treatment Diagnostic Retinopathy Study circle. Thickness of each layer was compared between groups, and the sectors with better area under the receiver operating characteristic curve (AUC) were identified.ResultsmGCL was significantly thinner in the POAG group, especially in outer and inner temporal sectors (p<0.001); and mRNFL was significantly thinner in the POAG group in the outer inferior and the outer superior sector (p<0.001). Diagnostic accuracy of inner macular layers was good, and in general mGCL was superior to mRNFL. pRNFL obtained the best diagnostic capability (AUC, 0.886). Horizontal and vertical Posterior Pole protocols performed similarly.ConclusionsInner macular layers using either horizontal or vertical B-scans, especially temporal sectors of mGCL, have good diagnostic capability to differentiate early glaucomatous eyes from control eyes; however, pRNFL has the highest diagnostic sensitivity for glaucoma detection.

Highlights

The advent of new spectral domain optical coherence tomography (SD-OCT) technology has allowed a more rapid acquisition of retinal images at a higher axial-image resolution, enabling better identification of individual retinal layers [1]
Results macular ganglion cell (mGCL) was significantly thinner in the primary open-angle glaucoma (POAG) group, especially in outer and inner temporal sectors (p
The present study analyzed the diagnostic ability of two individual inner macular layers obtained using a new segmentation software, with Posterior Pole protocols of Spectralis SD-OCT

Summary

Introduction

The advent of new spectral domain optical coherence tomography (SD-OCT) technology has allowed a more rapid acquisition of retinal images at a higher axial-image resolution, enabling better identification of individual retinal layers [1]. There has been an increasing interest in the importance of evaluating inner macular layers in glaucoma diagnosis [2]. There are different OCT instruments available with different retinal segmentation algorithms. Some of them such as Cirrus HD-OCT (Carl Zeiss Meditec, Jena, Germany) delimit together ganglion cell layer and inner plexiform layer (GCL-IPL). Others like RTVue SD-OCT (Optovue, Inc., Fremont, CA) segment together macular retinal nerve fiber layer (mRNFL) and GCL-IPL, which is the called ganglion cell complex (GCC). The new software of the Spectralis OCT (Heidelberg Engineering, Inc., Heidelberg, Germany) is the first one able to measure each of the 10 histological retinal layers individually

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