[Systemic perfusion times in non-arteritic anterior ischemic optic neuropathy]

The pathogenesis of non-arteritic anterior ischemic optic neuropathy (AION) is not well understood. Local factors like elevated IOP or a low C/D ratio may play a role, as may systemic arteriosclerosis or reduced perfusion pressure. Reduced cardiac output may also contribute to the pathogenesis of the disease. We therefore investigated 17 healthy young persons, 9 patients with non-arteritic AION, and 10 age-matched controls using fluorescence perfusion scintigraphy, a technique that allows subclavia carotid time to be determined. Subclavia carotid time measures the circulation time of the heart and lung and is proportional to cardiac output. The mean subclavia carotid time of healthy young persons was 9.1 +/- 1.6 s, 9.9 +/- 1.9 for AION patients, and 9.9 +/- 1.2 s for age-matched controls. The differences were statistically not significant. The correlation of perfusion times with blood pressure values showed, however, that systemic hypertension is accompanied by a relatively slow systemic perfusion time. In conclusion, it was not possible to demonstrate an absolutely reduced cardiac output in patients with non-arteritic AION during the day. Nevertheless, a drop in systemic blood pressure during the night may be responsible for a reduction in the blood supply to the optic nerve.