Optic nerve avulsion: Case report

Introduction: Optic nerve avulsion is a traumatic disinsertion of optic nerve fibres from the globe at the level of the lamina cribrosa. It is an uncommon and severe complication of blunt ocular trauma.

Case presentation: We report the case of a 15 years old male presented to the emergency department after being kicked by a horse. Initial ophthalmologic examination of the left eye (LE), exhibited eyelid hematoma, subconjunctival hemorrhage, VA was limited to light perception and there was a left relative afferent pupillary defect. Dilated fundus examination of the LE revealed an extensive vitreous and preretinal hemorrhage overlaying the optic disc and retina edema.The diagnosis of LE optic nerve head avulsion (ONA) was made. Five years after the accident, VA of LE detecting hand motion, fundus examination revealed a superior dragging of the optic disc, fibroglial scarring, retinal vessel narrowing and retinal epithelium hyperplasia.

Clinical discussion: In case of ONA, the avulsion can be missed initially due to vitreous and retinal hemorrhage overlaying the optic nerve, in such cases multimodal imaging can be a useful tool to the diagnosis and to evaluate associated ocular damage. Healing process of the avulsed optic nerve is characterized by the development of fibroglial proliferation. Visual outcome is poor and the final visual acuity range from light perception or no light perception in total ONA.

Conclusion: Optic head nerve avulsion is a rare and severe disease and initial diagnosis is challenging due to associated media opacities. The prognosis is poor and the injury leads to permanent visual impairment.