Innervation of the conjunctiva.

A parasympathetic pathway from the facial nerve to the conjunctiva was confirmed. Many conjunctival nerve fibres were degenerated following pterygopalatine ganglion lesion in cynomolgus monkeys. Nerve terminal degeneration was found mainly in the large vessel walls and adjacent to the subepithelial capillaries. AChE positive nerve fibres of undenervated tissue, probably representing the cholinergic fibres of facial nerve origin, and sympathetic nerve terminals, identified by their small granular vesicle content, were similarly disposed in vessel walls. Hence conjunctival vessels, including capillaries, have a dual autonomic innervation. Intraepithelial terminals were sparse and no evidence of a specific goblet cell innervation was found. Human perilimbal conjunctiva displayed a similar distribution of nerve fibres to cynomolgus monkeys.