Optic Nerve Avulsion: Pattern and Etiologies at a Tertiary Eye Care Center in Saudi Arabia: An 8-Year Retrospective Study

Abstract

Purpose: Optic nerve avulsion (ONA) is a rare but serious presentation of ocular trauma. This study investigates the presenting characteristics and etiologies of all cases of ONA over an 8-year-period at a tertiary eye care center in the Middle East.

Methods: The medical records of patients diagnosed with ONA at an Ophthalmic Emergency Department between November 2014 and November 2022 were analyzed in this retrospective cohort study. Data were collected on patient age, sex, affected eye, cause of injury and imaging studies. The best-corrected visual acuity (BCVA) at presentation and at the last follow-up visit, and the duration of follow-up were documented.

Results: The study sample was comprised of 44 eyes of 43 patients with ONA with median age of 16.5 (9.3-26.8) years ranging from 2 years old to 70 years old. There were (35;79.5%) males and (9; 20.5%) females. Most cases presented with an affected left eye (27; 61.4%) followed by the right eye (16; 36.4%) and only one patient (2.3%) had bilateral ONA. The most common cause of trauma resulting in ONA was a metallic object (8;18.2%). This study demonstrates the value of multi-sequence Magnetic resonance imaging (MRI) in the setting of unexplained vision loss when other modalities are inadequate or inconclusive.

Conclusion: Ophthalmic morbidity resulting from ONA can be devastating. Metallic object injuries were the most prevalent cause of ONA. The presence of associated media opacities challenges the initial diagnosis of ONA. In the vast majority of cases, the vision ended as no light perception (NLP), indicating permanent vision impairment.

Keywords: avulsion; ocular; optic nerve; trauma.

Figure 1

B-scan ultrasonography of a 9-year-old boy injured in his right eye by a door handle. His vision was NLP in the right eye. Red arrow: displays widened pattern of the optic nerve. Yellow arrow: funnel-shaped vitreous hemorrhage extending from the optic nerve head towards the vitreous. Green arrow: moderate to marked thickening of the peripapillary region.

Figure 2

(A) Wide field color fundus photo of the right eye of a 10-year-old boy injured in the right eye by a metallic rod. NLP was his vision in the right eye. Indicating vitreous hemorrhage, optic nerve avulsion and inferior retinal detachment. Day one of presentation. (B) Spectral domain optical coherence topography horizontal cut showing clear avulsion of optic nerve associated with retinal detachment and vitreous hemorrhage of the same patient. (C) Wide field color fundus photo of the left eye of a 7-year-old boy injured in the left eye by a horseshoe showing scattered inferior vitreous hemorrhage, 360 peri-papillary hemorrhage and hyperemic day one of the presentation. (D) Fundus photo of the left eye of the patient after one year follow-up demonstrating disc pallor and peri-papillary atrophy. NLP was his vision in the left eye.

Figure 3

CT and MRI of the orbit demonstrate traumatic optic nerve avulsion in a 21-year-old male with NLP vision following ocular trauma by an iron object. (A) Normal initial CT scan with no evidence of optic nerve sheath rupture. (B and C) Axial and coronal T2 fat saturation images revealed a widened optic nerve pattern (arrow) after two days of follow-up with loss of the optic nerve sheath around the proximal optic nerve.