The latent period of the pupil light reflex in lesions of the optic nerve.

The latent period of the pupil light reflex was investigated by means of infrared pupillography in patients suffering from optic neuritis (retrobulbar neuritis, papillitis), papilledema, optic atrophy or anterior ischemic optic neuropathy. The inflammatory diseases of the optic nerve and the optic atrophy cause significant prolongation of the latent period of the pupil light reflex. Conversely, in papilledema no prolonged latent period could be demonstrated. The vascular diseases of the optic nerve affect the pupil latent period also, however, to a lower degree.