Background
Traumatic optic neuropathy (TON) is a serious sequel of head trauma, leading even to loss of vision. Experimental studies suggest that vascular factors contribute to the pathogenesis of TON. Thus the purpose of this study was to explore associations between blood flow Doppler parameters in the central retinal artery (CRA) and optic nerve function in patients after closed head trauma.
Material and Method
Blood flow was evaluated by color-coded duplex sonography (CCDS) in the CRA of 72 consecutive patients (57 males and 15 females, mean age: 40+/-14.5, range: 15-77 years) with a diagnosis of traumatic optic neuropathy. Of the 101 affected eyes, optic nerve atrophy was found in 87 whereas the optic disc had normal appearance in the remaining 14 eyes.
Results
Both peak-systolic velocity (PSV) and end-diastolic velocity (EDV) in the eyes with TON were significantly lower (26% and 20%, respectively, p<0.01) than those in age- and gender-matched healthy subjects. A statistically significant decrease in PSV was also noted in the CRA of the contralateral unaffected eye (9%, p<0.05). A statistically significant positive association was found between blood flow velocities in the CRA and visual acuity (p<0.01) after controlling for sex, side of symptoms, and blood pressure.
Conclusions
Blood flow is significantly decreased in the central retinal artery of the affected eye and slightly in the unaffected eye in patients with traumatic optic neuropathy. Hemodynamic disturbances within the central retinal artery concur with functional nerve impairment.

Keywords: Retinal Artery - ultrasonography, Ultrasonography, Doppler, Color, Regional Blood Flow, Optic Nerve Injuries - ultrasonography, Adolescent, Accidents, Visual Acuity - physiology