Ocular Hypertension Treatment Study (OHTS) (OHTS)

To determine whether medical reduction of intraocular pressure prevents or delays the onset of glaucomatous visual field loss and/or optic disc damage in ocular hypertensive participants judged to be at moderate risk for developing open-angle glaucoma.

To produce natural history data to assist in identifying patients at most risk for developing open-angle glaucoma and those most likely to benefit from early medical treatment.

To quantify risk factors for developing open-angle glaucoma among ocular hypertensive individuals.

Study Overview

Status

Completed

Detailed Description

OHTS Phase 3 will re-examine study participants 20 plus years after enrollment to document clinical status and the incidence and severity of self-reported functional limitations. The 279 participants who developed POAG in OHTS Phase 1 or 2 will have more than 10 years of post-POAG follow-up by Phase 3. The timing of re-examination at 20 years is meaningful because 20 years approaches the median life expectancy of OHT patients in their 60's and 70's and half the median life expectancy of patients in their 40's and 50's. For the first time, patients with ocular hypertension and clinicians will have high quality data about the long-term risk of developing POAG and functional limitations associated with the disease. These data will facilitate patient-centered care so that patients and clinicians can decide on the appropriate frequency of tests and examinations and the potential benefit of preventative treatment.

Glaucoma is one of the leading causes of blindness in the United States and other industrialized countries. It is estimated that 2 million people in the United States have glaucoma and that 80,000 of these individuals are legally blind from the disease. Among African Americans, glaucoma is now recognized as the leading cause of blindness.

Elevated intraocular pressure (IOP), a common condition affecting 3 to 6 million people in the United States, is thought to be the leading risk factor for development of open-angle glaucoma. There is no consensus that medical reduction of intraocular pressure prevents or delays the onset of visual field and/or optic nerve damage in ocular hypertensive subjects.

Despite the lack of convincing evidence for the efficacy of medical treatment in ocular hypertension, approximately 1.5 million glaucoma suspects in the United States are being treated with costly ocular hypotensive medications that carry the potential for serious and even life-threatening side effects.

Clearly, there is a need for a well-controlled clinical trial to determine whether medical reduction of IOP can prevent or delay the onset of glaucomatous damage in ocular hypertensive subjects. Only then can clinicians and patients make rational choices and health care planners ensure that limited medical resources are being allocated in a safe and cost-effective manner.

The Ocular Hypertension Treatment Study (OHTS) is a long-term, randomized, controlled multicenter clinical trial. Ocular hypertensive subjects judged to be at moderate risk of developing primary open-angle glaucoma are randomly assigned to either close observation only or a stepped medical regimen. Medical treatment consists of all commercially available topical ocular hypotensive eye drops.

After completion of baseline measures (IOP, visual fields, disc photos) and randomization, the subjects are followed for a minimum of 5 years with automated threshold central static perimetry (Humphrey program 30-2) twice yearly and stereoscopic optic disc photographs once yearly. Study end points are reproducible visual field loss and/or progressive optic disc damage in either eye of a patient attributed to glaucoma by a Masked Endpoint Committee. All visual fields and optic disc photographs are read in a masked fashion in Reading Centers.

In the 1991 Baltimore Eye Survey, African Americans were shown to have a prevalence of open-angle glaucoma four to five times higher than whites. Given this high prevalence of glaucoma in the African American population, it is important to recruit and follow an adequate sample of African American subjects in the trial (approximately 25 percent of the total patient sample).

At the conclusion of this study, practitioners should be able to make reasonable estimates of risk for individual ocular hypertensive patients and to determine which ocular hypertensive individuals are most likely to benefit from early prophylactic medical treatment.

Study Type

Interventional

Enrollment (Actual)

1636

Phase

  • Phase 3

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

40 years to 80 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Men and nonpregnant women between the ages of 40 and 80 with IOP greater than or equal to 24 mm Hg but less than or equal to 32 mm Hg in at least one eye and IOP greater than or equal to 21 but less than or equal to 32 mm Hg in the fellow eye, as well as normal visual fields and optic discs are eligible for the trial. Patients presenting with best-corrected visual acuity worse than 20/40 in either eye, previous intraocular surgery, a life-threatening or debilitating disease, secondary causes of elevated IOP, angle-closure glaucoma or anatomically narrow angles, other diseases that can cause visual field loss, background diabetic retinopathy, optic disc abnormalities that can produce visual field loss or obscure the interpretation of the optic disc, or unwillingness to undergo random assignment are excluded from the trial.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
No Intervention: Observation
Close Observation.
Other: Treatment
Participants treated with commercially available topical ocular hypotensive eye drops.
Topical ocular hypotensive eye drops.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Incidence of Primary Open-Angle Glaucoma in Hypotensive Patients
Time Frame: 5 yrs (OHTS I, June 2002) and 13.0 yrs (completion of both phases of OHTS, March 2009)
Comparison of the cumulative proportion of participants who develop primary open-angle glaucoma in the observation and medication groups.
5 yrs (OHTS I, June 2002) and 13.0 yrs (completion of both phases of OHTS, March 2009)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Study Chair: Michael A Kass, MD, Washington University Department of Ophthalmology and Visual Sciences

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 1, 1994

Primary Completion (Actual)

June 1, 2002

Study Completion (Actual)

June 30, 2019

Study Registration Dates

First Submitted

September 23, 1999

First Submitted That Met QC Criteria

September 23, 1999

First Posted (Estimate)

September 24, 1999

Study Record Updates

Last Update Posted (Actual)

June 2, 2020

Last Update Submitted That Met QC Criteria

May 20, 2020

Last Verified

May 1, 2020

More Information

Terms related to this study

Other Study ID Numbers

  • NEI-24
  • 5U10EY009307-16 (U.S. NIH Grant/Contract)
  • 5U10EY009341-14 (U.S. NIH Grant/Contract)

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Ocular Hypertension

Clinical Trials on Topical ocular hypotensive eye drops.

Subscribe