- ICH GCP
- US Clinical Trials Registry
- Clinical Trial NCT00926913
Investigating Optical and Neural Causes of Vision Loss
April 3, 2015 updated by: US Department of Veterans Affairs
With the aging of the population, the prevalence of age-related macular degeneration (AMD) eye disease has resulted in a large number of people suffering from central vision loss.
In fact, the most prevalent cause of blindness among veterans is AMD.
Since the number of elderly veterans is expected to double in the next 10 years, loss of vision due to AMD is also expected to proportionally and considerably escalate.
People with impaired vision have difficulty with daily activities, such as, reading, driving, and recognizing faces.
The goal of the research project is to provide information on factors that contribute to visual impairment.
This knowledge is necessary for the development of innovative approaches that will optimize the benefit of vision rehabilitation techniques, aimed at improving vision, thus allowing our veterans to maintain function and productivity.
The findings from the proposed research will benefit our veterans and all aging people.
Study Overview
Status
Withdrawn
Conditions
Detailed Description
Vision loss has become a major public health problem due to the growth and aging of the population.
Age-related macular degeneration (AMD) is the most common cause of vision loss in people over 50 years of age.
In the United States, over 10 million people have AMD and over 1.6 million people age 50 and older have late-stage advanced AMD.
It is well established that AMD patients with central vision loss use preferred retinal loci (PRL) which are peripheral retinal areas adjacent to the fovea for performing daily activities, such as reading.
However, even in healthy eyes, peripheral vision is limited due to reduced neural sampling density compared to the fovea.
Additionally, the function of the peripheral retina can be further reduced in patients, owing to degenerative disease processes.
These neural substrate losses are coupled with losses in the quality of the optical image on the retina.
Optical imperfections increase with age and off-axis viewing, compared to viewing along the optical axis of the eye.
The combination of these factors plays a significant role in reducing visual performance of patients with eccentric fixation.
The long term goal of the project is to improve the visual performance of veterans with central vision loss by development of innovative approaches that will optimize the benefit of vision rehabilitation techniques.
In the current proposal, optical and neural losses will be assessed in AMD patients with central vision loss using novel techniques.
Increased optical losses due to age and viewing off the optical axis of the eye will be established with wavefront analysis technology.
Increased neural losses due to retinal dysfunction at PRL will be determined based on measurement of visual acuity with blurred stimuli.
Improvement in reading speed will be evaluated, conditional on neural losses at PRL and/or the stability of PRL, after compensating for optical losses with our adaptive optics system.
The findings will provide knowledge of PRL function and stability that is beneficial for improving the outcome of available vision rehabilitation methods that train patients to better use their PRLs.
Also, customized correction of optical imperfections of the eye for effectively improving visual performance can be developed as an approach for better vision rehabilitation of patients.
Optimizing vision rehabilitation of our veterans will allow them to maintain function and productivity.
Study Type
Observational
Contacts and Locations
This section provides the contact details for those conducting the study, and information on where this study is being conducted.
Study Locations
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Illinois
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Chicago, Illinois, United States, 60612
- Jesse Brown VA Medical Center, Chicago, IL
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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
50 years and older (Adult, Older Adult)
Accepts Healthy Volunteers
Yes
Genders Eligible for Study
All
Sampling Method
Non-Probability Sample
Study Population
Normal healthy subjects and patients diagnosed with age-related macular degeneration and central vision loss will participate in the study.
Description
Inclusion Criteria:
Standard inclusion criteria are:
- qualification for entry into the study based on clinical evaluation,
- competence to understand and willingness to sign an informed consent form and participate in the study,
- pupils that dilate to 5 mm or more.
The inclusion criteria for normal subjects will be:
- corrected visual acuities better than 20/30,
- intraocular pressure less than 21 mm Hg,
- no family history of AMD,
- no history of ophthalmic surgery or neurologic disease,
- no history of diabetes, glaucoma, or a history of elevated intraocular pressure.
The recruitment will ensure that approximately 40 subjects will fall into each of the three age groups, 50 to 60 years, 61 to 70 years, and 71 years and older. One eye of each subject will be selected at random to be included in the study.
Exclusion Criteria:
- Ocular opacities that preclude acquiring a clear fundus photograph or refractive errors greater than 4 diopters.
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
Cohorts and Interventions
Group / Cohort |
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Group 1
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What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Time Frame |
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Ocular aberrations
Time Frame: One time only
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One time only
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Collaborators and Investigators
This is where you will find people and organizations involved with this study.
Investigators
- Principal Investigator: Mahnaz Shahidi, PhD, Jesse Brown VA Medical Center, Chicago, IL
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
December 1, 2014
Primary Completion (Actual)
March 1, 2015
Study Completion (Anticipated)
July 1, 2015
Study Registration Dates
First Submitted
June 22, 2009
First Submitted That Met QC Criteria
June 23, 2009
First Posted (Estimate)
June 24, 2009
Study Record Updates
Last Update Posted (Estimate)
April 6, 2015
Last Update Submitted That Met QC Criteria
April 3, 2015
Last Verified
April 1, 2015
More Information
Terms related to this study
Keywords
Additional Relevant MeSH Terms
Other Study ID Numbers
- C7002-R
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.
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