• Previously, there was no feature of optic nerve head anatomy or physiology that could
explain the greater susceptibility for early damage in some nerve fibers by chronic
glaucoma. Using a new technique for scanning electron microscopic examination of human
optic nerve heads, regional differences were found in the fine structure of the lamina
cribrosa. The superior and inferior parts of the lamina at the level of the sclera appear to
contain larger pores and thinner connective tissue support for the passage of nerve-fiber …