Advanced Glaucoma Intervention Study (AGIS)



National Eye Institute (NEI)

Brief Summary

To assess the long-range outcomes of sequences of interventions involving trabeculectomy and
argon laser trabeculoplasty in eyes that have failed initial medical treatment for glaucoma.

Detailed Description

In advanced glaucoma, medication alone no longer reduces intraocular pressure adequately, and
the eye has field defects. Before 1980, some type of filtering surgery, such as
trabeculectomy, was the usual method of intervention. Since then, laser trabeculoplasty has
become a popular alternative. Sometimes the first intervention chosen succeeds in controlling
pressure for many years; at other times, the success lasts only a few weeks or months.
Because success is limited, some patients, over time, need to undergo a sequence of surgical
interventions. Little is known about which sequence gives the best long-range outcome.

The Advanced Glaucoma Intervention Study (AGIS) is designed to provide a comprehensive
assessment of the long-range outcomes of medical and surgical management in advanced
glaucoma. The study uses visual function status to compare two intervention sequences in
managing the disease.

Eligible eyes are randomly assigned to one of two intervention sequences: (1) trabeculectomy,
followed by argon laser trabeculoplasty (ALT) should trabeculectomy fail, followed by a
second trabeculectomy should ALT fail; or (2) ALT, followed by trabeculectomy should ALT
fail, followed by another trabeculectomy should the first trabeculectomy fail. Antifibrotic
agents may be used as an adjunct to trabeculectomy, but only in eyes with a previous history
of invasive surgery. Eyes that fail the entire assigned sequence of interventions are managed
at the discretion of the AGIS physician in collaboration with the patient.

Interventions are supplemented with medical treatment as needed. A total of 789 eyes with
advanced glaucoma have been enrolled. All patients are being followed under a standardized
protocol for a minimum of 5 years to determine degree of visual function loss, failure rates
of interventions, rates of complications, and need for supplemental therapy.

After the initial intervention, followup examinations are scheduled at 1 week, 4 weeks, 3
months, 6 months, and every 6 months thereafter. After second and third interventions,
followup examinations are scheduled at 1 and 4 weeks. Additional visits are scheduled as
necessary for the management of the disease.

The primary outcome variable in AGIS is average percent of eyes with decrease of vision,
where decrease of vision is a substantial decline of either visual field or visual acuity
attributable to the effect of glaucoma. Secondary outcome variables include sustained
decrease of vision, failure of interventions, number of prescribed glaucoma medications, and
level of intraocular pressure. An ancillary study is assessing filtering bleb encapsulation.

Overall Status

Unknown status

Start Date


Completion Date


Primary Completion Date



Phase 3

Study Type




Intervention Type


Intervention Name

Intervention Type


Intervention Name



Men and women between the ages of 35 and 80 with open-angle glaucoma that was not
successfully controlled by medication were eligible for enrollment.



Minimum Age

35 Years

Maximum Age

80 Years

Healthy Volunteers




Yale University School of Medicine, Yale Eye Center
New Haven Connecticut United States
Georgetown University, University Ophthalmic Consultants of Washington, Eye Associates of Washington, D.C.
Washington District of Columbia United States
Emory University, Emory Eye Center
Atlanta Georgia United States
Piedmont Hospital, Eye Consultants of Atlanta
Atlanta Georgia United States
Humana Health Plan Sykes Center
Chicago Illinois United States
University of Illinois, Eye and Ear Infirmary
Chicago Illinois United States
Washington Hospital Center, Washington Eye Physicians and Surgeons
Chevy Chase Maryland United States
University of Michigan, W.K. Kellogg Eye Center
Ann Arbor Michigan United States
Sinai Hospital, Detroit, Franklin Eye Consultants
Southfield Michigan United States
Ohio State University, Department of Ophthalmology, Ophthalmic Surgeons and Consultants
Columbus Ohio United States
Wills Eye Hospital, Glaucoma Service
Philadelphia Pennsylvania United States
University of Virginia Medical Center, Department of Ophthalmology
Charlottesville Virginia United States
Medical College of Virginia, Department of Ophthalmology
Richmond Virginia United States

Location Countries


United States

Verification Date


Lastchanged Date


Firstreceived Date


Has Expanded Access


Condition Browse

Firstreceived Results Date




The Advanced Glaucoma Intervention Study (AGIS) Manual of Operations. Springfield, Virginia., National Technical Information Service, 1993;No. PB93-220192


Ederer F, Gaasterland DE, Sullivan EK; AGIS Investigators. The Advanced Glaucoma Intervention Study (AGIS): 1. Study design and methods and baseline characteristics of study patients. Control Clin Trials. 1994 Aug;15(4):299-325.




Advanced Glaucoma Intervention Study. 2. Visual field test scoring and reliability. Ophthalmology. 1994 Aug;101(8):1445-55.




The Advanced Glaucoma Intervention Study (AGIS) Data Management Handbook. Springfield, Virginia., National Technical Information Service, Document, 1996;No. PB96-137120


The Advanced Glaucoma Intervention Study (AGIS): 3. Baseline characteristics of black and white patients. Ophthalmology. 1998 Jul;105(7):1137-45.




The Advanced Glaucoma Intervention Study (AGIS): 4. Comparison of treatment outcomes within race. Seven-year results. Ophthalmology. 1998 Jul;105(7):1146-64.



Firstreceived Results Disposition Date


Study Design Info



Primary Purpose


Study First Submitted

September 23, 1999

Study First Submitted Qc

September 23, 1999

Study First Posted

September 24, 1999

Last Update Submitted

June 2, 2006

Last Update Submitted Qc

June 2, 2006

Last Update Posted

June 5, 2006

Last Known Status

Active, not recruiting processed this data on August 27, 2018


Conditions usually refer to a disease, disorder, syndrome, illness, or injury. In, conditions include any health issue worth studying, such as lifespan, quality of life, health risks, etc.

Interventions refer to the drug, vaccine, procedure, device, or other potential treatment being studied. Interventions can also include less intrusive possibilities such as surveys, education, and interviews.
Study Phase

Most clinical trials are designated as phase 1, 2, 3, or 4, based on the type of questions that study is seeking to answer:

In Phase 1 (Phase I) clinical trials, researchers test a new drug or treatment in a small group of people (20-80) for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.

In Phase 2 (Phase II) clinical trials, the study drug or treatment is given to a larger group of people (100-300) to see if it is effective and to further evaluate its safety.

In Phase 3 (Phase III) clinical trials, the study drug or treatment is given to large groups of people (1,000-3,000) to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.

In Phase 4 (Phase IV) clinical trials, post marketing studies delineate additional information including the drug's risks, benefits, and optimal use.

These phases are defined by the Food and Drug Administration in the Code of Federal Regulations.

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