Purchase this article with an account.
J. Albon, J. E. Morgan, B. Povazay, G. Jeffery, A. Unterhuber, B. Hermann, Y.-C. Tham, W. Drexler; Three-Dimensional Ultrahigh Resolution Oct of the Optic Nerve Head in the Tree Shrew. Invest. Ophthalmol. Vis. Sci. 2007;48(13):4259.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To determine the potential for three-dimensional ultrahigh resolution optical coherence tomography (3D-UHR OCT) in allowing high resolution reconstruction of the optic nerve head, lamina cribrosa and retinal nerve fiber layer.
High speed (up to 25000 depth-scans/second) ultrahigh resolution OCT at 800 nm with 160 nm bandwidth with isotropic resolution of less than 2-3 µm has been developed for three-dimensional visualization of intraretinal morphology in excised optic discs of the adult tree shrew (Tupaia belangeri). Animals were sacrificed by deep anesthesia and then perfused transcardially with phosphate buffered saline followed by 4% paraformaldehyde. Optic nerves heads, with 2 mm of surrounding retina, were excised from four eyes for imaging by 3D-UHR OCT. Following cryoprotection in 30% sucrose, optic nerve heads were then cryoembedded and 8 µm sections were stained using H&E or examined by Nomarski optics.
Three-dimensional ultrahigh resolution OCT allows detailed comparison with well known retinal morphology from histology and, in particular, delineation of the astroglial and scleral aspects of the lamina cribrosa. Demarcation of the retinal layers was facilitated by the high isotropic resolution of UHR OCT enabling scaled measurements of retinal nerve fiber layer thickness and the configuration of the scleral lamina. OCT tomograms corresponded well to all the main intraretinal layers observed in histological sections. The higher sampling rate available with three dimensional OCT imaging enabled detailed comparison with histological features.
3D ultrahigh resolution OCT permits detailed in vitro analysis of optic nerve head structure. The correlation with histological features is excellent and this method will allow the determination of scaling factors for accurate interpretation of in vivo ultrahigh resolution ophthalmic OCT tomograms. The tree shrew, with its well developed lamina cribrosa, seems an ideal species in which to pursue these studies.
This PDF is available to Subscribers Only