• Horseradish peroxidase was injected into various areas of the optic disc of monkeys to label retrograde axoplasmic transport and permit identification and mapping of ganglion cells projecting through the areas of injection. Peripheral ganglion cell axons project through the deeper layers of the peripapillary nerve fiber layer (NFL) and enter the peripheral optic nerve. Peripapillary ganglion cell axons project through those coming from peripheral locations to superficial positions in the NFL, then to the central optic nerve. The Bjerrum portion of the optic nerve head includes approximately the central 30° of the superior and inferior temporal quadrants of the disc. The course of nerve fiber bundles corresponding to those most susceptible to glaucoma (Bjerrum area) is regularly and predictably organized horizontally and vertically in the nerve head.
Minckler DS. The Organization of Nerve Fiber Bundles in the Primate Optic Nerve Head. Arch Ophthalmol. 1980;98(9):1630-1636. doi:10.1001/archopht.1980.01020040482019