Purpose:
To describe the morphometry of 3D digital reconstructions ofthe human optic nerve head (ONH) and eventually compare theseresults between normal donors and those with open angle glaucoma(OAG).
Methods:
Donor eyes underwent endoscopic vitrectomy, were maintainedat 10mmHg for 30 minutes with a BSS infusion, then fixed with2% Glutaraldehyde/1% Paraformaldehyde. ONHs from 3 normal and3 donors eye pairs with OAG were reconstructed with 1.5µmvoxel resolution. 14 landmarks were delineated within 40 serial,radial, digital, sagittal sections. Measurements from the firstreconstructed normal eye pair are presented using methods previouslyreported in primates (Yang H, etal, IOVS 2007).
Results:
Fig. 1 illustrates the principle surfaces in the donor eyesand morphometry of the landmarks. BMO plane errors were smallin these eyes (16 µm od,13 µm os). Differences betweeneyes for scleral thickness were small (0.4%) as were area measuresfor all principle structures (2-6%), but larger BMO Area (16%),for laminar thickness (26%) and all depth measures (17-35%).Fig. 2 illustrates marked scleral thinning adjacent to the discmargin.
Conclusions:
High-fidelity reconstructions of the human optic nerve fromdonor eyes fixed at physiologic pressures can be used to definethe principle landmarks similarly to methods developed in primateeyes. These techniques may prove valuable in defining variationsin the ONH that may underlie biomechanical susceptibility toglaucomatous injury.
Keywords: optic nerve • lamina cribrosa • sclera