A Comparison of Optic Nerve Head Morphology Viewed by Spectral Domain Optical Coherence Tomography and by Serial Histology

Abstract

PURPOSE To compare serial optic nerve head (ONH) histology with interpolated B-scans generated from a three-dimensional (3D) spectral domain OCT (SD-OCT) ONH volume acquired in vivo from the same normal monkey eye. METHODS A 15°, ONH SD-OCT volume was acquired in a normal monkey eye, with IOP controlled at 10 mmHg, using the Heidelberg Spectralis. Following perfusion fixation at 10 mmHg, the ONH was trephined, embedded in a paraffin block and sagittal sections were cut at 4 μm intervals. The location of each section was identified within the optic disc photograph by matching the position of the retinal vessels and of Bruch’s membrane opening. By altering the angles of rotation and incidence, “interpolated” B-scans matching the location of the histologic sections were generated using custom software. Structures identified in the histologic sections were compared to signals identified in matched B-scans. RESULTS Close matches between histologic sections and interpolated B-scans were identified throughout the extent of the ONH. SD-OCT identified the neural canal opening as the termination of the Bruch’s membrane/retinal pigment complex and Border Tissue as the innermost termination of the choroidal signal. The anterior lamina cribrosa and its continuity with the prelaminar glial columns were also detected. CONCLUSIONS Volumetric SD-OCT imaging of the ONH was capable of generating interpolated B-scans which accurately matched serial histologic sections. In this single monkey ONH, SD-OCT captured the anterior laminar surface, which is likely to be a key structure in the detection of early ONH structural damage in ocular hypertension and glaucoma.

Optical Coherence Tomography of the Swollen Optic Nerve Head: Deformation of the Peripapillary Retinal Pigment Epithelium Layer in Papilledema

“…This study confirms that in addition to revealing peripapillary RNFL thickening associated with papilledema, 19 -21 HD-OCT is able to detect changes in the subsurface architecture of the ONH and peripapillary region 23 (Williams GSN, et al IOVS 2009;50:ARVO E-Abstract 2253). Papilledema with intracranial hypertension results in an inward bowing of the RPE/BM layer at the NCO not typically seen in normal eyes or other forms of disc edema.…”

A Global Shape Index to Characterize Anterior Lamina Cribrosa Morphology and Its Determinants in Healthy Indian Eyes

“…32 The position of the anterior LC was defined by a sharp increase in axial signal intensity below the optic disc, extending laterally up to the LC insertion points in the peripapillary sclera. 33 Points corresponding to the LC were manually marked on each B-scan using our custom application. In total, 150 to 300 discrete points were marked for each eye.…”

“…This strategy was similar to that in a previous study. 33 In order to ensure consistency in measurements across different eyes, a common reference system was used. To that end, the BMO planes and centers (now taken as origin) of all patients were superimposed (Figs.…”

Age-Related Differences in Longitudinal Structural Change by Spectral-Domain Optical Coherence Tomography in Early Experimental Glaucoma

“…15,[41][42][43] Customized ''Multiview'' software (built on the Visualization Toolkit [VTK; Kitware, Inc., Clifton Park, NY, USA]) was used to delineate the following anatomic features within 40 of the 80 radial B-scans (every other scan) of each SD-OCT data set by two trained technicians who were masked to the status of each eye (EG versus control) and time point (baseline or postlaser): internal limiting membrane (ILM), outer boundary of RNFL, Bruch's membrane/retinal pigment epithelium complex (BM/RPE), BMO (innermost termination of the BM/RPE complex), neural boundary (inner border of the neural canal), and anterior lamina cribrosa surface (Fig. 2).…”

“…Bruch's membrane opening was delineated using two discrete points at either side of the neural canal. The anterior lamina cribrosa surface was delineated based on previous direct comparisons between SD-OCT B-scans and matched histologic sections, 41 recent comparisons to threedimensional (3D) histomorphometric reconstructions (Zangalli C, et al IOVS 2014;55:ARVO E-Abstract 4747), as well as our previous publications on SD-OCT laminar visualization 42 and longitudinal change detection. 15,43 For each SD-OCT Bscan data set, a point cloud including all the above landmarks was generated (Figs.…”