24-HOUR BLOOD-PRESSURE MONITORING IN PATIENTS WITH ANTERIOR ISCHEMIC OPTIC NEUROPATHY

Objective: To define parameters of ambulatory diurnal blood pressure i n patients who had experienced anterior ischemic optic neuropathy (AIO N) in a case-controlled study. Participants and Methods: Twenty-four p atients with AION and 24 control subjects who were matched for age, ge nder, medical diagnoses, and medications underwent ambulatory automate d blood pressure monitoring for 24 hours. Results: The overall diurnal pattern of blood pressure appeared to be normal in all subjects, show ing lower blood pressures at night than during the day, an overnight n adir, and an ascending blood pressure curve in the morning to reach da ytime levels. Also, patients with AION did not differ from control sub jects with respect to the nighttime diastolic nadir or daytime peak sy stolic blood pressure. However, during the daytime, patients with AION had lower mean systolic and diastolic blood pressures than did matche d control subjects. The widest difference between their blood pressure curves occurred after awakening in the morning, when patients with AI ON had a less steep and more irregular rise of blood pressure. Patient s who had signs of vertebrobasilar insufficiency in addition to AION h ad lower mean diastolic blood pressure during both daytime and nightti me and a lower minimum daytime diastolic blood pressure. Conclusions: On ambulatory measurements of diurnal blood pressure, patients with AI ON consistently had a lower mean blood pressure than did control subje cts and a lag in the usual rise in blood pressure in the morning to me et increasing daytime demands for perfusion. Chronic hypoperfusion of small end-arterial vessels that supply the optic nerve head may predis pose to AION, acid may be caused by relative hypotension owing to over treated hypertension or to abnormal vascular autoregulation. Internist s should be asked to monitor blood pressure carefully when treating hy pertensive patients who are at risk for AION, to avoid hypotension, es pecially on awakening in the morning.