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. Author manuscript; available in PMC: 2012 Aug 1.
Published in final edited form as: Exp Eye Res. 2010 Sep 16;93(2):120–132. doi: 10.1016/j.exer.2010.09.005

Figure 3. The volume flow of blood within the posterior ciliary arteries should be affected by IOP-related stress and strain within the peripapillary sclera and scleral flange.

Figure 3

The posterior ciliary arteries pass through the peripapillary sclera (yellow, left and center panel) immediately adjacent to the scleral portion of the neural canal. We refer to this portion of the sclera as the scleral flange (yellow, middle panel) (Yang et al., 2005. Neural Canal and Peripapillary Scleral Alterations Within Three-Dimensional Reconstructions of Early Glaucoma Monkey Optic Nerve Heads. Invest. Ophthalmol. Vis. Sci. 46, ARVO Abstract# 3511). The sclera thins here to accommodate an expansion of the neural tissues that occurs in a highly eye-specific fashion. While the large penetrating vessels to the choroid are outside of the flange, the circle of Zinn-Haller and the penetrating branches that pass to the pre-laminar, laminar and retrolaminar nerve pass directly through these tissues and are therefore subject to the compressive effects of their contained mechanical stress and strain. Within the lamina cribrosa, there is no direct blood supply to the axons or the axon bundles. Each laminar beam contains a capillary (Panel F, Figure 1) which are here shown in a vascular casting of a monkey eye (Cioffi and Van Buskirk, 1996). (Left and right panels reprinted with permission from The Glaucomas. St. Louis: Mosby; 1996:177–97.(Cioffi and Van Buskirk, 1996)