Peripheral nerve pathway to the ciliary muscle

Abstract

The oculomotor nerve was sectioned intracranially on one side of a cynomolgus and two rhesus monkeys and nerve tissue from various positions distal to the lesion was examined using light and electron microscopy following fixation by perfusion 8, 9 and 10 days after operation respectively. Degeneration of ciliary ganglion terminals was observed subsequent to neurotomy but all ciliary nerve fibres were of normal appearance when examined at the level of the choroid. Ciliary muscle fibres and terminals were similarly unchanged but evidence of muscle fibre relaxation was seen. The results indicate that the peripheral accommodation nerve pathway shares the feature of a relay in the ciliary ganglion with the pupil constrictor pathway, contrary to the conclusions of Westheimer and Blair 1973.