Overview
Traumatic optic neuropathy (TON) occurs with direct damage to the eye or its adnexa, damaging the optic nerve.
It can be classified according to the location of the injury. Trauma anterior to where the ophthalmic artery enters the optic nerve will cause swelling of the optic disc and associated retinal haemorrhages. This presentation is less common than posterior TON that causes optic atrophy with no visible swelling of the nerve. Optic atrophy occurs approximately 6 weeks after the initial injury. Some case examples of posterior TON are available within this resource on the page titled “Primary optic atrophy” (link at the bottom of this page).
Anterior TON is more common in eyes with no/minimal visible cup and it has been proposed that blunt trauma causes damage of the scleral canal thereby interrupting axoplasmic flow and leading to oedema of the optic nerve. The swelling in anterior TON has been described in the literature as a "pallid" swelling, similar to ischaemic causes of disc swelling.
References
Kai B. Kang, Scott Jones, [...], and Heather E. Moss (2016) Optic Neuropathy with Delayed Onset After Trauma: Case Report and Review of the Literature. Neuroophthalmology. 40(4): 188–191.
Steinsapir, KD. Goldberg, RA. (2011) Traumatic Optic Neuropathy: An Evolving Understanding,
American Journal of Ophthalmology, Volume 151, Issue 6, pp 928-933.
Yu-Wai-Man, P. (2015) Traumatic optic neuropathy—Clinical features and management issues Taiwan J Ophthalmol. 5(1): 3–8.