Three-dimensional evaluation of the lamina cribrosa using spectral-domain optical coherence tomography in glaucoma

Abstract

PURPOSE. To introduce a novel, digital, three-dimensional (3D) reconstruction of the optic nerve head (ONH) and to use this method to evaluate the 3D configuration of the lamina cribrosa (LC) in patients with primary open-angle glaucoma. METHODS. Optic discs of 137 eyes of 137 patients with openangle glaucoma were scanned with enhanced depth-imaging spectral domain-optical coherence tomography (SD-OCT). 3D images of the ONH were then reconstructed from B-scan images using maximum intensity projection (MIP) and texturebased volume rendering (VRT). The performance of the threshold segmentation by MIP and VRT was assessed by comparing the distance of the anterior LC surface from the reference line set at the Bruch's membrane opening level (LC depth) measured within both of the 3D images and the B-scan images. RESULTS. The LC configuration could be evaluated three dimensionally in ~95% of patients scanned with enhanced depthimaging SD-OCT. The mean LC depth was 559.50 ± 151.98, 558.97 ± 152.39, and 560.22 ± 152.26 μm in B-scan, MIP, and VRT images, respectively. There were excellent agreements between the values (intraclass correlation coefficient = 1.000 between MIP and B-scan, and 0.999 between VRT and B-scan). The configuration of the LC varied considerably among individual glaucoma patients. CONCLUSIONS. This method provides measurable 3D images of the LC that enable comprehensive evaluation of the LC configuration. This technique should facilitate the investigation of the LC in glaucomatous eyes. © 2012 The Association for Research in Vision and Ophthalmology, Inc.