Figure 1. Photomicrograph of the optic nerve head (staining: PAS); arrows #1 and #2: pia mater of the optic nerve; arrow #3: end of Bruch's membrane; arrow #4: projection of the outer margin of the pia mater of the optic nerve; Gamma zone: region between arrows #3 and #4; black star: beginning of dura mater of the optic nerve.
