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. Author manuscript; available in PMC: 2010 Jan 1.
Published in final edited form as: Invest Ophthalmol Vis Sci. 2008 Sep 4;50(1):224–234. doi: 10.1167/iovs.08-2464

Figure 2. Parameter Regionalization.

Figure 2

Neural canal offset (A) and depth data (B) for each neural canal landmark were pooled for eight anatomic regions, superior (S), superonasal (SN), nasal (N), inferonasal (IN), inferior (I), inferotemporal (IT), temporal (T), and superotemporal (ST). The S, N, I, and T regions contained all marks within 60° sections of the ONH centered about the S-I and N-T clinical axes, and the SN, IN, IT, and ST regions contained all marks in 30° radial sections of the ONH centered about the SN-IT and IN-ST axes. Concentric rings represent the different neural canal landmarks from its internal entrance BMO to its external exit PSCO as shown in the superior region of (A) and (B). Neural canal Depth measurements start with the ASCO rather than BMO.(C) Using the center of BMO,12 radial sections perpendicular to BMO zero reference plane divided the volumetric parameters into 24, 15 radial regions. Then regional volumes were projected onto BMO zero reference plane, color coded by region and overlaid onto a standard ellipse. (D) Within the lamina, position and thickness, prelaminar tissue thickness data were pooled into 17 regions according to the three radial regions (central; MP, middle periphery; P, periphery) and eight quadrants same as in (A) and (B). (E) Peripapillary sclera position data were pooled into 16 regions according to two radial regions (MP, middle periphery, inner boundary starting from ASCO ellipse (dark black line) to an ellipse whose size is 1.62 times of the ASCO ellipse size; P, periphery, inner boundary starting from the outer boundary of the MP regions to an ellipse whose size is 2.34 times of the ASCO ellipse size). (F) Peripapillary scleral thickness data were pooled into 24 regions according to three radial regions (F, flange thickness, covered area from ASCO to PSCO; MP, middle periphery region, inner boundary starting from PSCO to an ellipse whose size is 1.62 times of the ASCO ellipse size; P, periphery regions are the same as peripapillary scleral position periphery regions).