Effect of Alphagan on Retinal Blood Flow Autoregulation and Motion Detection in Patients With Normal Pressure Glaucoma
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.
|Study Design:||Endpoint Classification: Efficacy Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||Effect of Brimonidine 0.15% on Retinal Blood Flow Autoregulation and Motion Detection in Patients With Normal Tension Glaucoma|
- Presence or Absence of Retinal Blood Flow Autoregulation [ Time Frame: 8 weeks ] [ Designated as safety issue: No ]
- Improvement in Motion Detection [ Time Frame: 8 weeks ] [ Designated as safety issue: No ]
|Study Start Date:||March 2010|
|Estimated Study Completion Date:||December 2013|
|Estimated Primary Completion Date:||December 2013 (Final data collection date for primary outcome measure)|
Drug: Alphagan (brimonidine) 0.15%
One drop in each eye three times a day for 8 weeks.
Other Name: Alphagan