Complications of Age-Related Macular Degeneration Prevention Trial

NCT ID: NCT00000167

Last Updated: 2010-03-24

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

COMPLETED

Clinical Phase

PHASE3

Total Enrollment

1052 participants

Study Classification

INTERVENTIONAL

Study Start Date

1999-05-31

Study Completion Date

2006-06-30

Brief Summary

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To determine whether application of low-intensity laser treatment of eyes with drusen in the macula can prevent later complications of age-related macular degeneration and thereby preserve visual function.

Detailed Description

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Complications of age-related macular degeneration (AMD) are the leading cause of severe vision loss among people aged 65 and over in the United States and many Western countries. Most, (approximately 90 percent), of this vision loss is due to the neovascular (or wet) form of AMD. The word neovascular describes the development of new, abnormal blood vessels in the back of the eye. Unfortunately, the majority of these new vessels are not amenable to currently available treatments.

The first sign that an eye may develop AMD is the presence of drusen, yellowish deposits under the retina. Current data suggests that eyes with large drusen are at increased risk for developing the vision threatening complications of AMD. Since the 1970s investigators have reported consistently that laser photocoagulation causes a reduction in large drusen. However, results of the effects of laser treatment on preventing later complications of AMD have been less consistent and based on relatively small numbers of patients.

Further study into the ability of a treatment to prevent vision loss from the advanced forms of AMD would have profound public health implications. A treatment that could reduce the risk of developing neovascularization by 30 percent might reduce the risk of blindness from AMD by one half. The Complications of Age-related Macular Degeneration Prevention Trial (CAPT) will assess whether treating drusen by laser photocoagulation reduces the risk of loss of visual acuity.

The CAPT is a multi-center, prospective, randomized clinical trial designed to assess the safety and effectiveness of low-intensity laser treatment in preventing vision loss among patients with large drusen in both eyes. A total of 1052 participants were enrolled in the study. Participants had one eye randomly assigned to laser treatment performed by a CAPT-certified ophthalmologist. The other eye was not treated. Both eyes were observed carefully for any changes for a period of five years. The effectiveness of the treatment was assessed using the following criteria:

Change in visual acuity (primary outcome measure of the study)

Incidence of complications of AMD such as neovascularization, serous detachment of the pigment epithelium, and geographic atrophy

Changes in contrast threshold and critical print size for reading

Quality of life assessments for patients, using the Visual Function Questionnaire 25 (VFQ-25), were conducted at the time of enrollment and at 5 years.

STUDY RESULTS:

Follow-up of patients was excellent; less than 3% of visual acuity examinations were missed. At 5 years, 188 (20.5%) treated eyes and 188 (20.5%) observed eyes had visual acuity scores ≥3 lines worse than at the initial visit (p= 1.00). The cumulative 5-year incidence rates for treated and observed eyes for CNV were 13.3% and 13.3% (p=0.95), respectively; and for GA were 7.4% and 7.8% (p=0.64), respectively. The contrast threshold doubled in 23.9% of treated eyes and in 20.5% of observed eyes (p=0.40). The critical print size doubled in 29.6% of treated eyes and in 28.4% of observed eyes (p=0.70). Seven (0.7%) treated eyes and 14 (1.3%) observed eyes had an adverse event of a ≥6 -line loss in visual acuity in the absence of late age-related macular degeneration or cataract.

As applied in CAPT, low intensity laser treatment did not demonstrate a clinically significant benefit on vision in eyes of people with bilateral large drusen.

Conditions

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Macular Degeneration

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

SINGLE_GROUP

Primary Study Purpose

PREVENTION

Blinding Strategy

SINGLE

Outcome Assessors

Study Groups

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1

Laser treatment

Group Type EXPERIMENTAL

Low-Intensity Laser Treatment

Intervention Type PROCEDURE

Initial: 60 barely visible burns, grid pattern. Re-treatment at 12 months: 30 barely visible burns, focal treatment.

Interventions

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Low-Intensity Laser Treatment

Initial: 60 barely visible burns, grid pattern. Re-treatment at 12 months: 30 barely visible burns, focal treatment.

Intervention Type PROCEDURE

Eligibility Criteria

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Inclusion Criteria

Age at least 50 years old

Vision in each eye must measure 20/40 or better.

At least 10 large drusen in each eye

Available for follow-up examinations for 5 years after enrollment

Final eligibility is determined through a detailed eye examination by a CAPT-certified ophthalmologist.
Minimum Eligible Age

50 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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National Eye Institute (NEI)

NIH

Sponsor Role lead

Responsible Party

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NEI

Principal Investigators

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Stuart L Fine, MD

Role: STUDY_CHAIR

Scheie Eye Institute, The University of Pennsylvania School of Medicine

Locations

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Retinal Consultants of Arizona, Ltd.

Mesa, Arizona, United States

Site Status

Retinal Consultants of Arizona, Ltd.

Peoria, Arizona, United States

Site Status

West Coast Retina Medical Group, Inc.

San Francisco, California, United States

Site Status

University of South Florida Eye Institute

Tampa, Florida, United States

Site Status

Emory Eye Center

Atlanta, Georgia, United States

Site Status

Northwestern University

Chicago, Illinois, United States

Site Status

Illinois Retina Associates, S.C.

Harvey, Illinois, United States

Site Status

University of Iowa

Iowa City, Iowa, United States

Site Status

Ophthalmology & Visual Sciences at the University of Louisville, School of Medicine

Louisville, Kentucky, United States

Site Status

The Johns Hopkins University

Baltimore, Maryland, United States

Site Status

Ophthalmic Consultants of Boston

Boston, Massachusetts, United States

Site Status

Associate Retinal Consultants, P.C.

Royal Oak, Michigan, United States

Site Status

Mayo Clinic

Rochester, Minnesota, United States

Site Status

Barnes Retina Institute

St Louis, Missouri, United States

Site Status

Retina-Vitreous Center, P.A.

Edison, New Jersey, United States

Site Status

Retina-Vitreous Center, P.A.

Lakewood, New Jersey, United States

Site Status

Southeast Clinical Research Associates

Charlotte, North Carolina, United States

Site Status

Retina Associates of Cleveland

Cleveland, Ohio, United States

Site Status

The Ohio State University, Department of Ophthalmology

Columbus, Ohio, United States

Site Status

Casey Eye Institute

Portland, Oregon, United States

Site Status

Retina Northwest, P.C.

Portland, Oregon, United States

Site Status

Scheie Eye Institute

Philadelphia, Pennsylvania, United States

Site Status

Texas Retina Associates

Dallas, Texas, United States

Site Status

University of Wisconsin - Madison, Department of Ophthalmology and Visual Sciences

Madison, Wisconsin, United States

Site Status

Countries

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United States

References

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Brader HS, Ying GS, Martin ER, Maguire MG; Complications of Age-Related Macular Degeneration Prevention Trial-CAPT Research Group. New grading criteria allow for earlier detection of geographic atrophy in clinical trials. Invest Ophthalmol Vis Sci. 2011 Nov 29;52(12):9218-25. doi: 10.1167/iovs.11-7493.

Reference Type DERIVED
PMID: 22039251 (View on PubMed)

Other Identifiers

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NEI-70

Identifier Type: -

Identifier Source: org_study_id

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