Optic nerve avulsion after blunt ocular trauma - Case report.

INTRODUCTION: Avulsion of the optic nerve head is a rare and severe complication of ocular blunt trauma. The case reported is a 28-year old man presenting to the emergency department due to blunt trauma to his right eye globe with a tree branch. Lid haematoma and subconjunctival haemorrhage were present. Visual acuity soon after the injury was counting fingers (CF) and on admission to the Department of Ophthalmology he had no light perception (NLP). Fundus examination revealed prepapillary haemorrhage, which after few days dispersed into the vitreous cavity. Despite no light perception in the affected eye, the patient was qualified for vitrectomy. During surgery, an optic nerve avulsion with cicatricial gliosis was diagnosed. Six months after vitrectomy, the visual acuity was NLP in the right eye.

DISCUSSION: The clinical signs, mechanism, treatment and natural history of this poorly known disease are described.

CONCLUSION: Optic nerve avulsion must be considered in cases of trauma with forced rotation of the eye. Damage occurring at the disc may suggest mechanisms involving anterior luxation of the globe, retropulsion of the nerve, forced globe rotation, or a sudden explosive rise in intraocular pressure blowing the nerve off the sclera into its dural sheath. Damage and break of the nerve fibres are responsible for immediate visual impairments, and involving secondary haematomas and oedemas In spite of required safety precautions in agriculture work, eye injuries are still prevalent. Blunt ocular trauma remains a large part of this group, leading even to irreversible blindness.