COVID-19 is an emerging, rapidly evolving situation.
Get the latest public health information from CDC:

Get the latest research information from NIH: Menu

Branch Vein Occlusion Study

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00000162
Recruitment Status : Completed
First Posted : September 24, 1999
Last Update Posted : June 24, 2005
Information provided by:
National Eye Institute (NEI)

Brief Summary:

To determine whether scatter argon laser photocoagulation can prevent the development of neovascularization.

To determine whether peripheral scatter argon laser photocoagulation can prevent vitreous hemorrhage.

To determine whether macular argon laser photocoagulation can improve visual acuity in eyes with macular edema reducing vision to 20/40 or worse.

Condition or disease Intervention/treatment Phase
Macular Degeneration Neovascularization, Pathologic Vitreous Hemorrhage Procedure: Macular Argon Laser Photocoagulation Procedure: Peripheral Scatter Argon Laser Photocoagulation Procedure: Scatter Argon Laser Photocoagulation Phase 3

Detailed Description:

Retinal branch vein occlusion (BVO) is the second most common retinal vascular disease after diabetic retinopathy. Many treatments for this disorder were attempted before 1977, but none were proven to be effective. The only treatment that seemed at all promising in preventing visual loss from BVO was laser photocoagulation.

Approximately 500 patients were enrolled in the study. One-half were randomly assigned to treatment with argon laser photocoagulation; the other one-half remained untreated as controls. For BVO with or without neovascularization, scatter treatment of 100 to 400 laser burns was applied in the drainage area of the occluded vein site, avoiding the fovea and optic disc. Individual laser burns were 200 to 500 microns in diameter with an exposure time of 0.1 to 0.2 seconds. For macular edema, burns of 50 to 100 microns in diameter with exposure time of 0.05 to 0.1 seconds were used. A fluorescein angiogram less than 1 month old had to have been available for each patient. Treatment was performed under topical anesthesia using the argon laser to achieve a grid pattern over the area of capillary leakage identified by fluorescein in the macular region. Photocoagulation was extended no closer to the fovea than the edge of the foveal avascular zone and did not extend peripherally beyond the major vascular arcade. The efficacy of treatment was judged on the basis of visual acuity measurements as well as assessment of the subsequent development of neovascularization and/or vitreous hemorrhage. Patients were followed for at least 3 years.

Layout table for study information
Study Type : Interventional  (Clinical Trial)
Allocation: Randomized
Primary Purpose: Treatment
Study Start Date : July 1977

Resource links provided by the National Library of Medicine

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Layout table for eligibility information
Ages Eligible for Study:   Child, Adult, Older Adult
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Patients with three types of diagnoses were accepted:

  1. major BVO without neovascularization;
  2. major BVO with neovascularization;
  3. BVO with macular edema and reduced vision. All patients must have had onset of signs and/or symptoms of BVO less than 18 months before the initial visit, vision of 5/200 or better, and sufficient clarity of the ocular media to permit confirmation of the condition with fundus photography. Other eligibility criteria apply to each of the three major groups as well as special cases such as the occurrence of bilateral disease.
Layout table for additonal information Identifier: NCT00000162    
Other Study ID Numbers: NEI-64
First Posted: September 24, 1999    Key Record Dates
Last Update Posted: June 24, 2005
Last Verified: October 1999
Additional relevant MeSH terms:
Layout table for MeSH terms
Macular Degeneration
Vitreous Hemorrhage
Neovascularization, Pathologic
Pathologic Processes
Retinal Degeneration
Retinal Diseases
Eye Diseases
Eye Hemorrhage