Characterization of peripapillary vascular density in traumatic optic neuropathy

Optical coherence tomography angiography is a novel imaging modality used to characterize pathologic vascular changes in the peripapillary region. Traumatic optic neuropathy is a common yet poorly defined entity, lacking evidence-based anatomic characterization. Optical coherence tomography angiography may be utilized in this pathology enhance patient evaluation and counseling.

A case series of patients presenting to a tertiary care center after periorbital trauma with unilateral traumatic optic neuropathy were included. Patients underwent optical coherence tomography angiography, with the contralateral unaffected eye imaged as a control. Conventional automated visual field testing and optical coherence technology imaging of the retinal nerve fiber layer and macula were additionally obtained.

Twelve eyes (six patients) were included. Eyes with traumatic optic neuropathy demonstrated significantly reduced vascular density in the inside disc and inferior regions compared with fellow control eyes on paired nonparametric analysis (both p = 0.0312), preceding detectable retinal nerve fiber layer thinning on structural coherence tomography or clinically apparent optic disc cupping. Greater inter-eye vessel density differences were observed in patients with stable or worsened visual acuity, with a trend toward association with final visual outcomes.

Optical coherence tomography angiography may offer an early characterization of disease severity and inform prognosis in traumatic optic neuropathy. Inferior and internal optic nerve areas demonstrated early preferential vascular compromise, without consistent accompanying clinically apparent optic disc cupping and structural retinal nerve fiber layer thinning, and may be associated with final visual acuity. Findings suggest that vascular compromise may occur in the absence of detectable structural changes in the optic nerve that inform functional prognosis. Additional studies assessing vessel density longitudinally and correlating with management are warranted.