PURPOSE: To determine whether a decrease in blood flow, measured by the Heidelberg retiinal flowmeter, can characterise a disc at risk and predict the occurrence of non-arteritic anterior ischaemic optic neuropathy (NAION). METHODS: Blood flow, volume and velocity were measured in the optic nerve heads of 14 unaffected fellow eyes of patients with unilateral NAION, and compared with those of the affected eyes and of the eyes of 7 age-matched healthy controls. RESULTS: The affected eyes were found to differ from the unaffected eyes in all three haemodynamic parameters. Flow (measured in arbitrary units) is the most important parameter to be taken into consideration. Blood flow was significantly lower in affected than in unaffected eyes (upper rim, p < 0.05; lower rim, p < 0.025). It was also significantly lower in the unaffected eyes than in the healthy control eyes (p < 0.005, upper and lower rims), and in the affected eyes than in the control eyes (p < 0.00005, upper and lower rims). CONCLUSION: Decreased blood flow in the optic nerve head may indicate a risk for NAION and be considered a characteristic of the disc at risk.
PURPOSE: To determine whether a decrease in blood flow, measured by the Heidelberg retiinal flowmeter, can characterise a disc at risk and predict the occurrence of non-arteritic anterior ischaemic optic neuropathy (NAION). METHODS: Blood flow, volume and velocity were measured in the optic nerve heads of 14 unaffected fellow eyes of patients with unilateral NAION, and compared with those of the affected eyes and of the eyes of 7 age-matched healthy controls. RESULTS: The affected eyes were found to differ from the unaffected eyes in all three haemodynamic parameters. Flow (measured in arbitrary units) is the most important parameter to be taken into consideration. Blood flow was significantly lower in affected than in unaffected eyes (upper rim, p < 0.05; lower rim, p < 0.025). It was also significantly lower in the unaffected eyes than in the healthy control eyes (p < 0.005, upper and lower rims), and in the affected eyes than in the control eyes (p < 0.00005, upper and lower rims). CONCLUSION: Decreased blood flow in the optic nerve head may indicate a risk for NAION and be considered a characteristic of the disc at risk.