Effect of Alphagan on Retinal Blood Flow Autoregulation and Motion Detection in Patients With Normal Pressure Glaucoma
Status:
Completed
Trial end date:
2012-09-01
Target enrollment:
Participant gender:
Summary
The investigators have completed a study in which the investigators examined the response of
the retinal circulation to changes in posture from sitting to lying down in patients with
Normal Tension Glaucoma (NTG). This alteration in position produces changes in the local
blood pressure at the entrance to the retinal vasculature. In a healthy retina, the
vasculature adapts by dilating and constricting in order to maintain a steady blood flow
rate. In an eye with NTG, this often does not occur. Upon analysis at the completion of the
study , the investigators found that the patients who had been taking Alphagan (brimonidine)
during the study did not exhibit the blood flow increases typical of NTG while lying down;
instead, they maintained a steady blood flow rate as did the group of healthy control
subjects. The investigators primary objective is to now demonstrate in a prospective study
that Alphagan can restore retinal vascular autoregulatory function in patients with NTG who
do not autoregulate. The investigators will also determine the effect of Alphagan treatment
on the patients' ability to detect motion.