Three-dimensional Reconstructed Imaging of Deep Structures of the Optic Disc by Optical Coherence Tomography Radial Sectioning

Abstract

Purpose: : The lamina cribrosa has been implicated in the origin of optic nerve damage in glaucoma on the basis of histopathological findings. Three-dimensional (3D) structural analysis of the optic disc is important for understanding the true nature of glaucoma because the lamina cribrosa has a 3D architecture. Previous study showed that optical coherence tomography (OCT) imaging could demonstrate the 3D structure of the lamina cribrosa. However, there are some limitations in delineating detailed deep structures of the optic disc from single scan images. On the other hand, high-resolution images can be obtained by using enhanced depth imaging (EDI) OCT and image averaging. In this study, we attempted to reconstruct 3D images using OCT radial sections.

Methods: : Deep structures of the optic disc were imaged by positioning a Heidelberg Spectralis close enough to the eye to obtain an inverted image; the image was then averaged for 50 scans. We obrained 12 and 24 radial sections of the optic disc from normal and glaucoma subjects, respectively; the inner limiting membrane, retinal pigment epithelium/bruch membrane complex, peripapillary inner scleral border, and lamina cribrosa surface were traced using ImageJ in each image. Fifteen and thirty images from normal and glaucoma subjects, respectively, were interpolated between each adjacent image, and 3D images of the optic disc were reconstructed using 3D image processing software (Avizo 3D Visualization Framework).

Results: : 3D images of the optic disc could be reconstructed using EDI OCT radial sectioning.

Conclusions: : 3D reconstructed imaging was helpful for understanding the deep structures of the optic disc. This technique would be useful for detecting disc abnormalities by further setting appropriate parameter values.

Keywords: optic disc • image processing • lamina cribrosa