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. Author manuscript; available in PMC: 2010 May 1.
Published in final edited form as: Invest Ophthalmol Vis Sci. 2009 Jan 10;50(5):2165–2174. doi: 10.1167/iovs.08-2786

Figure 5. Two principal Border Tissue configurations, their relationship to a pigmented or unpigmented extension of Bruch’s Membrane and the resultant clinical disc margin anatomy.

Figure 5

  1. Internally Oblique
    The diagram shows the clinical optic disc appearance (above) and a cross section of the optic nerve head (below). Labeling is as follows:
    • 1 = Sclera
    • 2 = Choriocapillaris
    • 3 = Retinal pigment epithelium with Bruch’s Membrane
    • 4 = Border Tissue
    • 5 = Neural canal boundary
    • 6 = Pigment on the surface of Bruch’s Membrane
    • 7 = Bruch’s Membrane
    Magnified Inset Left - pigmented Bruch’s Membrane corresponds to the halo of pigment on the left side of the disc margin
    Magnified Inset Right - a region of unpigmented Bruch’s Membrane is shown; this corresponds to a white crescent internal to the pigment halo at the disc margin (which corresponds to a portion of pigmented Bruch’s Membrane)
  2. Externally Oblique
    Labeling is as per the schematic in panel A
    Magnified Inset Left - Bruch’s Membrane is pigmented to its end and does not extend beyond the termination of the Border Tissue. This Bruch’s Membrane extension corresponds to an external crescent of pigment at the disc margin that is internal to the termination of the retinal pigment epithelium. The portion of the Border Tissue that is internal to the end of Bruch’s Membrane (BMO) may be clinically recognizable as an inner reflective (if there is no pigment on the Border Tissue surface) or a pigmented crescent (if there is pigment on the Border Tissue surface) that is posterior to the plane of the retinal pigment epithelium. An inner pigmented halo (lighter grey and stippled) is shown on both sides of the disc diagram
    Magnified Inset Right-unpigmented Bruch’s Membrane extends internally to the Border Tissue termination, corresponding to a reflective crescent internal to the pigment crescent. Again, pigmented Border Tissue (lighter grey and stippled) extends internal to the reflective crescent. In both the left and right insets the Border Tissue/scleral junction is depicted without a true scleral lip which when present and visible, appears internal and deep to the other structures