An observational study in Glaucoma, sponsored by VA Office of Research and Development. Completed at 1 site in United States. Open to participants aged 18 Years to 99 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2017-03-21.
Sponsored by VA Office of Research and Development · Observational
Improved Assessment of Visual Field Change is a trial aimed at investigating mechanisms of visual field testing variability. The investigators have found using larger stimulus size substantially lowers short-term variability. In this study, the investigators will determine if larger stimuli detect visual field change at an earlier time. The investigators are also developing a statistical model that accounts for correlations of neighboring test locations.
Disease of the optic nerve, including glaucoma, is the leading cause of blindness in the United States. Treatment decisions for optic nerve diseases are based largely on the changes in visual function that occur mostly as a consequence of disease progression. Unfortunately, the decision as to whether change of visual function has occurred is often difficult because of the high retest variability of conventional visual field testing (perimetry). This variability is so high that with moderate visual loss, a minimum of six tests are often needed in patients with optic nerve damage to reliably distinguish visual field deterioration from random variation. The preliminary data show that a substantial portion of the variability of perimetry lies in the type of stimulus used and the testing strategy applied.
OBJECTIVES: The investigators propose to test the hypothesis that a large portion of total perimetric variability in patients with visual loss is due to a poor signal-to-noise ratio associated with using a small fixed-size stimulus.
RESEARCH PLAN AND METHODS: To test this hypothesis, the investigators are examining patients with optic nerve diseases with conventional automated perimetry (size III) and tests having large-sized and scaled stimuli (size V, size VI (custom perimeter) and luminance size threshold perimetry - a test where threshold is found by changing stimulus size rather than stimulus intensity). Over four years the investigators will test 100 patients with and glaucoma and 60 normals each eight times. In addition, the investigators are retesting 50 subjects once a week for 5 weeks. The investigators are also studying the associated structural-functional correlations using OCT and developing a statistical model that accounts for correlations of neighboring test locations.
Perimetric variability and the reliable identification of visual field change is the single most difficult problem in visual testing today. The investigators anticipate identifying a method that allows efficient and accurate determination of visual field change. Identification of a superior method would (1) reduce the number of examinations needed, thereby reducing the costs of medical care; (2) minimize misdiagnosis, unnecessary testing and even unnecessary surgery that results from mistakenly interpreting fluctuation of the visual field as progression or improvement; (3) allow earlier disease intervention and (4) reduce the costs of clinical trials.
1,818 studies on the registry are indexed under Glaucoma; 231 are open to participants now.
This study's enrollment of 180 is above the median of 103 across 454 observational studies indexed under Glaucoma.
Browse Glaucoma studies →VA Office of Research and Development is the lead sponsor of 1,733 studies on the registry; 396 are open to participants now.
Of its 206 completed or terminated interventional studies of FDA-regulated products, 180 (87%) have results posted.
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glaucoma patient with 0 to -25 dB mean deviation and normal subjects
Exclusion Criteria:
glaucoma
Procedure: Comparison of four visual field testing strategies
normal
Procedure: Comparison of four visual field testing strategies
We compared the ability of four perimetric strategies to detect visual field change in the glaucoma arm.
Number of Subjects Progressing in Each Group Using Pointwise Linear Regression
Perimetric method that most efficiently detects visual field change. secondary outcome: number of subjects progressing in each group using pointwise linear regression Linear regression was used to determine visual field worsening (progression) at each of 52 test locations. We required 3 or more worsening test locations at a p = 0.05 significance level for their to be significant progression.
Time frame: 4 years
We completed recruitment in the first three years of the grant period at out Visual Field Laboratory at the University of Iowa
| Milestone | Group 1 | Group 2 |
|---|---|---|
| Started | 120 | 60 |
| Completed | 92 | 47 |
| Not completed | 28 | 13 |
| Withdrew: Death | 3 | 3 |
| Withdrew: Withdrawal by subject | 25 | 10 |
Perimetric method that most efficiently detects visual field change. secondary outcome: number of subjects progressing in each group using pointwise linear regression Linear regression was used to determine visual field worsening (progression) at each of 52 test locations. We required 3 or more worsening test locations at a p = 0.05 significance level for their to be significant progression.
| participants | Glaucoma | Control |
|---|---|---|
| Number of Subjects Progressing in Each Group Using Pointwise Linear Regression | 0 | 0 |
Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Group 1 | — | 0/120 (0%) | 0/120 (0%) |
| Group 2 | — | 0/60 (0%) | 0/60 (0%) |
| Age, Categorical(Participants) | Group 1 | Group 2 | Total |
|---|---|---|---|
| <=18 years | 0 | 0 | 0 |
| Between 18 and 65 years | 25 | 41 | 66 |
| >=65 years | 95 | 19 | 114 |
| Age, Continuous(years) | Group 1 | Group 2 | Total |
|---|---|---|---|
| Mean | 68 ± 9 | 61 ± 9 | 64 ± 9 |
| Sex: Female, Male(Participants) | Group 1 | Group 2 | Total |
|---|---|---|---|
| Female | 73 | 43 | 116 |
| Male | 47 | 17 | 64 |
| Region of Enrollment(Participants) | Group 1 | Group 2 | Total |
|---|---|---|---|
| United States | 120 | 60 | 180 |
Plan to share: Undecided
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VA Office of Research and Development