The Collaborative Initial Glaucoma Treatment Study: study design, methods, and baseline characteristics of enrolled patients

Ophthalmology. 1999 Apr;106(4):653-62. doi: 10.1016/s0161-6420(99)90147-1.


Objective: The Collaborative Initial Glaucoma Treatment Study (CIGTS) is a randomized, controlled clinical trial designed to determine whether patients with newly diagnosed open-angle glaucoma (primary, pigmentary, or pseudoexfoliative) are better treated by initial treatment with medications or by immediate filtration surgery.

Design: Randomized, controlled clinical trial.

Participants: A total of 607 patients with open-angle glaucoma were enrolled.

Intervention: Patients randomized to initial medications (n=307) received a stepped regimen of medications to lower intraocular pressure. Those randomized to initial surgery (n=300) underwent trabeculectomy to lower intraocular pressure.

Main outcome measures: Progression in visual field loss constitutes the study's primary outcome variable. Secondary outcomes include health-related quality of life, visual acuity, and intraocular pressure.

Results: Randomized assignment resulted in a balanced distribution between treatment groups for most demographic and clinical measures assessed at enrollment. More males than females were enrolled (55% were males), and a substantial percentage (38.1 %) of enrollees were blacks. Most enrollees (90.6%) were diagnosed with primary open-angle glaucoma; the remainder had either pseudoexfoliative (4.8%) or pigmentary (4.6%) forms of open-angle glaucoma.

Conclusions: Follow-up of this well-characterized group of patients should provide well-rounded guidance, based on both traditional ophthalmic measures and patients' perspectives on their health-related quality of life, on how best to initially treat open-angle glaucoma.

Publication types

  • Clinical Trial
  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adrenergic beta-Antagonists / therapeutic use*
  • Adult
  • Aged
  • Clinical Trials as Topic / methods*
  • Drug Therapy, Combination
  • Female
  • Follow-Up Studies
  • Glaucoma, Open-Angle / diagnosis
  • Glaucoma, Open-Angle / physiopathology
  • Glaucoma, Open-Angle / therapy*
  • Humans
  • Intraocular Pressure
  • Male
  • Middle Aged
  • Quality of Life
  • Research Design*
  • Trabeculectomy*
  • Visual Acuity
  • Visual Fields


  • Adrenergic beta-Antagonists