Corneal nerve access in monkeys.

Electron microscopical examination of corneal nerves in rhesus and cynomolgous monkeys revealed that limbal, subepithelial nerves gained direct access to the corneal epithelium. Epithelial axons occurred singly and infrequently and they were confined to the basal layer of cells. All nerves of the stroma terminated within the layer and rami perforans were not found. The apparent barrier to nerve passage presented by Bowman's layer in monkeys was discussed in relation to primates in general. The isolation of stromal and epithelial nerve fibres confirms that terminals occur in both layers and their respective potential for excitation was briefly discussed.