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Cause of Pigment Dispersion Syndrome

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: NCT00005919
Recruitment Status : Completed
First Posted : June 19, 2000
Last Update Posted : March 4, 2008
Information provided by:
National Institutes of Health Clinical Center (CC)

Brief Summary:

The purpose of this study is to learn how pigment is released from the iris (the colored part of the eye) in patients with pigment dispersion syndrome. It will do this by examining the response of the pupil (the central opening of the iris) to a flash of light to determine what is happening in the iris to cause release of the pigment.

In pigment dispersion syndrome, pigment released from the iris is deposited in other parts of the eye, including the trabecular meshwork-a filter-like tissue in the front of the eye. Aqueous fluid (fluid continuously produced by the eye) normally flows out of the eye through the trabecular meshwork. In some patients, the pigment deposits may block tiny holes in the meshwork, preventing the fluid from flowing out. This can cause an increase in eye pressure that may lead to glaucoma and some loss of vision. Understanding how pigment is released from the iris may help predict the course of pigment dispersion syndrome and identify which patients will likely develop increased eye pressure.

Patients with pigment dispersion syndrome and normal volunteers may be eligible for this study. All participants will have the following procedures, which will be completed in two clinic visits:

First visit

  1. Examination of the front of the eyes, including the cornea, iris and lens.
  2. Vision testing and measurements of visual field and eye pressure.
  3. Examination of the trabecular meshwork. For this test, a contact lens is placed on the eye after the eye has been numbed with anesthetic drops.

Second visit

  1. Refraction (dilation of the pupils with drops) and examination of the back of the eyes, including the optic nerve.
  2. Reaction of the pupils to low-level infrared light (pupillography). During this 15-minute test, the patient or volunteer wears a lightweight headband with two small cameras mounted on it. The cameras-one which views the eye and the other the subject's field of view-record pupil dilation and position.

The test results in patients with pigment dispersion syndrome will be compared with those in normal volunteers. Patients will be followed every 6 months (or more often, if medically indicated) during the 3-year study to determine changes in eye pressure or visual field. Volunteers will be asked to return about once a year for 3 years for repeat pupillography.

Condition or disease
Glaucoma Healthy Pigment Dispersion Syndrome

Detailed Description:
The purpose of this study is to conduct a comprehensive ophthalmologic evaluation and comparison of two types of patients and to compare them to normal controls. The two types of patients are those with pigment dispersion (PDS) with normal intraocular pressure (IOP) and those with PDS and elevated IOP. The hypothesis to be tested is that a developmental abnormality of the iris pigment epithelium (IPE) and the dilator muscle is the fundamental defect responsible for the pigment dispersion. This defect may involve other structures of the eye such as the ciliary and retinal pigment epithelium. The results of pupillography in PDS with or without elevated IOP and asymmetric PDS (one eye versus fellow eye) will be the outcome parameters.

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Study Type : Observational
Enrollment : 90 participants
Official Title: Etiology of Pigment Dispersion Syndrome (PDS)
Study Start Date : June 2000
Study Completion Date : August 2003

Resource links provided by the National Library of Medicine

Information from the National Library of Medicine

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Ages Eligible for Study:   Child, Adult, Older Adult
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes


All patients entering the study must have black pigment deposition on the trabecular meshwork at the site of Schlemm's canal equal to or greater than 2-plus on the goniophotographic scale of 1 to 5 plus.

Although this condition is rare amongst African-Americans, every effort will be made to recruit such individuals.


Patients with exfoliation syndrome, uveitis, trauma, pigment dispersion with posterior chamber intra-ocular lens, pigmented tumors, primary open-angle glaucoma, other conditions with associated pigment dispersion such as acute angle-closure glaucoma, ocular hemorrhage, Horner's syndrome.

In addition, normal volunteers will be recruited as controls. They will be free of any eye disease and be matched for age, sex and degree of myopia.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00005919

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United States, Maryland
National Eye Institute (NEI)
Bethesda, Maryland, United States, 20892
Sponsors and Collaborators
National Eye Institute (NEI)
Layout table for additonal information Identifier: NCT00005919    
Other Study ID Numbers: 000155
First Posted: June 19, 2000    Key Record Dates
Last Update Posted: March 4, 2008
Last Verified: August 2003
Keywords provided by National Institutes of Health Clinical Center (CC):
Pigment Dispersion
Ocular Hypertension
Pupil Reaction
Natural History
Pigment Dispersion Syndrome
Gene Mutation
Additional relevant MeSH terms:
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Glaucoma, Open-Angle
Pathologic Processes
Ocular Hypertension
Eye Diseases