NCT04396002 · University of Alabama at Birmingham
Glaucoma, Visual Field Loss, and Their Association With Life Space in Older Adults
What this study is about
Mobility refers to a person's purposeful movement through the environment from one place to another and can be conceptualized as a continuum from bed bound (immobility) on one extreme to making excursions to distant locations on the other extreme.
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Mobility refers to a person's purposeful movement through the environment from one place to another and can be conceptualized as a continuum from bed bound (immobility) on one extreme to making excursions to distant locations on the other extreme. Primary open-angle glaucoma (POAG) is a chronic, progressive optic neuropathy that can lead to gradual loss of vision in the peripheral field and central vision. Older adults with POAG have an increased risk for motor vehicle collisions and falls. Moreover, existing studies suggest that patients with POAG exhibit more postural sway while standing as measured by a balance platform and also tend to walk more slowly than those who are normally sighted and free of ocular disease. While these disturbances likely influence mobility, there has been little research directly assessing the impact of POAG on mobility. This study will assess the impact of POAG on life space (one aspect of mobility) and will determine whether difficulties with life space are associated with difficulties experienced under conditions of dim lighting.
Interventions
DIAGNOSTIC_TEST
Life Space Questionnaire
This 9-item questionnaire is interested in finding out how much a person gets out and about and the spatial extent of the person's typical life space, i.e., what is the usual range of places in which the person engages in activities within the designated time frame.
DIAGNOSTIC_TEST
Low Luminance Questionnaire
This 32-item questionnaire is interested in finding out problems that involve vision under different lighting conditions or feelings that people have about your vision under different lighting conditions.
DIAGNOSTIC_TEST
Contrast sensitivity under dim illumination
Participants will be presented with visual targets of different contrast under dim illumination and asked to report when they see the target.
DIAGNOSTIC_TEST
Visual field under dim illumination (MAIA)
Sensitivity in the central visual area will be assessed under dim illumination
DIAGNOSTIC_TEST
Macular Pigment Optical Density (MPOD)
Participants will be asked to look at a fixation target and the density of their macular pigment will be assessed.
DIAGNOSTIC_TEST
Dark Adaptation
After adapting to a dark environment, participants will be exposed a bright flask of light. the time needed for them to recover their sensitivity will be measured.
Primary outcome measures
Assessment of life space measured with the Life Space Questionnaire
Time frame: Through study completion, an average of 1 year
The Life Space Questionnaire is a 9-item questionnaire that assesses how much a person gets out and about and the spatial extent of the person's typical life space, i.e., what is the usual range of places in which the person engages in activities within the designated time frame. Patients are asked to respond either Yes or No.
Assessment of vision under low luminance conditions
Time frame: Through study completion, an average of 1 year
The Low Luminance Questionnaire is a 32-item questionnaire that assesses how participants see under dim illumination and how well they can perform different tasks (e.g. reading, driving). Patients are asked to select a response among different choices on a Likert scale that ranges from 1 to 5, 1 to 6, 1 to 7, or 1 to 8 depending on the question. A response of "1" indicates that the participant experiences no difficulty while increasingly higher numbers indicate increasing amounts of difficulty.
Differences in contrast sensitivity functions between controls and patients
Time frame: Through study completion, an average of 1 year
Participants will be presented with targets of different spatial frequency at different contrasts. Their sensitivity at each spatial frequency will be recorded/
Differences in dark adaptation between controls and patients
Time frame: Through study completion, an average of 1 year
Once participants have adapted to a dark environment, they will be exposed to a bright flash of light. The time needed to recover their visual sensitivity will be measured (rod-intercept time).
Differences in visual sensitivity under dim illumination between controls and patients
Time frame: Through study completion, an average of 1 year
Participants will be presented with targets at different locations in their visual fields under dim illumination.
Differences in Macular Pigment Optical Density between controls and patients
Time frame: Through study completion, an average of 1 year
Participants will fixate on a target while their MPOD is assessed. The MPOD is measured using the Heidelberg optical coherence tomography (OCT) MPOD module. Two different light sources are directed to the back of the eye. The light is reflected back and the OCT/MPOD computes the difference in the reflectance of the two lights which is an estimate of the density of macular pigment.
Assessment of the relationship between each the measure of visual function and life space
Time frame: Through study completion, an average of 1 year
The relationship between each of the measures of visual function (dark adaptation, contrast sensitivity functions, visual fields under dim illumination, and MPOD) and life space (Life Space Questionnaire will be assessed.
Assessment of the relationship between each the measure of visual function and self-reported visual function under dim illumination
Time frame: Through study completion, an average of 1 year
The relationship between each of the measures of visual function (dark adaptation, contrast sensitivity functions, visual fields under dim illumination, and MPOD) and self-reported visual performance under dim illumination (Low Luminance Questionnaire) will be assessed.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- (Patients):
- Participants that are enrolled in the Early Detection of Glaucoma Progression using a Novel Individualized Approach (IRB-300000301) or in the African Descent and Glaucoma Evaluation (ADAGES) IV: Alterations of the Lamina Cribrosa in Progression (IRB-161115004).
Exclusion criteria
- (Patients):
- Not being enrolled in one of the following two NIH-funded studies: 1. African Descent and Glaucoma Evaluation (ADAGES) IV: Alterations of the lamina cribrosa in progression (EY026574) or 2. Early detection of glaucoma progression using a novel individualized approach (EY025756) Inclusion Criteria (Controls):
- No diagnosis of eye disease Exclusion Criteria (Controls):
- Cognitive impairment that would preclude ability to take the tests
Where
- Birmingham, Alabama
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Sep 12, 2025 · Source of record for eligibility and locations