24-hour blood pressure monitoring in patients with anterior ischemic optic neuropathy
K. Landau, J. M. Winterkorn, L. U. Mailloux, W. Vetter and B. Napolitano
Department of Ophthalmology, University Hospital, Zurich, Switzerland.
OBJECTIVE: To define parameters of ambulatory diurnal blood pressure in
patients who had experienced anterior ischemic optic neuropathy (AION) in a
case-controlled study. PARTICIPANTS AND METHODS: Twenty-four patients with
AION and 24 control subjects who were matched for age, gender, medical
diagnoses, and medications underwent ambulatory automated blood pressure
monitoring for 24 hours. RESULTS: The overall diurnal pattern of blood
pressure appeared to be normal in all subjects, showing lower blood
pressures at night than during the day, an overnight nadir, and an
ascending blood pressure curve in the morning to reach daytime levels.
Also, patients with AION did not differ from control subjects with respect
to the nighttime diastolic nadir or daytime peak systolic blood pressure.
However, during the daytime, patients with AION had lower mean systolic and
diastolic blood pressures than did matched control subjects. The widest
difference between their blood pressure curves occurred after awakening in
the morning, when patients with AION had a less steep and more irregular
rise of blood pressure. Patients who had signs of vertebrobasilar
insufficiency in addition to AION had lower mean diastolic blood pressure
during both daytime and nighttime and a lower minimum daytime diastolic
blood pressure. CONCLUSIONS: On ambulatory measurements of diurnal blood
pressure, patients with AION consistently had a lower mean blood pressure
than did control subjects and a lag in the usual rise in blood pressure in
the morning to meet increasing daytime demands for perfusion. Chronic
hypoperfusion of small end-arterial vessels that supply the optic nerve
head may predispose to AION, and may be caused by relative hypotension
owing to overtreated hypertension or to abnormal vascular autoregulation.
Internists should be asked to monitor blood pressure carefully when
treating hypertensive patients who are at risk for AION, to avoid
hypotension, especially on awakening in the morning.
