Variability in Perimetry Study (VIPII)

Improved Assessment of Visual Field Change

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.

Study Overview

• Status: Completed
• Conditions: Glaucoma
• Intervention / Treatment: Procedure: Comparison of four visual field testing strategies

Detailed Description

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.

• Study Type: Observational
• Enrollment (Actual): 180

Contacts and Locations

Study Locations

• United States
  • Iowa
    • Iowa City, Iowa, United States, 52246-2208
      • Iowa City VA Health Care System, Iowa City, IA

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 99 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

glaucoma patient with 0 to -25 dB mean deviation and normal subjects

Description

Inclusion Criteria:

• Mean deviation of -20 or better with 5-8 points (optimally 10 points) with a value of p= 0.05 or better on the total deviation plot
• Mild cataract with VA of 20/30 or better pinholed
• Refractive error of = to or less than 6 diopters with = or less than 3.50 diopters of cylinder
• Pupil diameter of 3 mm minimum
• Controlled hypertension, diabetes, migraine
• Pseudophakic/refractive surgery if no vision problems
• Trabeculectomy okay

Exclusion Criteria:

• History of other ocular or neurologic disease or surgery
• History of stroke
• Systemic disease [lupus, graves, cancer (within the last 5 yrs), AIDS, other]
• History of amblyopia
• Unreliable patient
• Frequently misses appointments
• Tests poorly
• Ocular hypertension
• Retinal problems
• Diabetic retinopathy
• Neurological disease (IIH, ON, AION)
• Cancer not in remission for the last 5 years
• Vein or artery occlusions
• Macular degeneration
• Trauma with vision loss
• Ocular inflammation (pars planitis, iritis, temporal aeuritis)

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Control
• Time Perspectives: Prospective

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Group 1; glaucoma	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.
Group 2; 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	4 years

Collaborators and Investigators

• Sponsor: VA Office of Research and Development
• Investigators: Principal Investigator: Michael Wall, MD, Iowa City VA Health Care System, Iowa City, IA

Publications and helpful links

General Publications

• Wall M, Doyle CK, Eden T, Zamba KD, Johnson CA. Size threshold perimetry performs as well as conventional automated perimetry with stimulus sizes III, V, and VI for glaucomatous loss. Invest Ophthalmol Vis Sci. 2013 Jun 7;54(6):3975-83. doi: 10.1167/iovs.12-11300.
• Kummet CM, Zamba KD, Doyle CK, Johnson CA, Wall M. Refinement of pointwise linear regression criteria for determining glaucoma progression. Invest Ophthalmol Vis Sci. 2013 Sep 19;54(9):6234-41. doi: 10.1167/iovs.13-11680.
• Wall M, Doyle CK, Zamba KD, Artes P, Johnson CA. The repeatability of mean defect with size III and size V standard automated perimetry. Invest Ophthalmol Vis Sci. 2013 Feb 15;54(2):1345-51. doi: 10.1167/iovs.12-10299.

Study record dates

Study Major Dates

• Study Start: July 1, 2010
• Primary Completion (Actual): September 1, 2015
• Study Completion (Actual): September 1, 2015

Study Registration Dates

• First Submitted: January 15, 2010
• First Submitted That Met QC Criteria: January 15, 2010
• First Posted (Estimate): January 20, 2010

Study Record Updates

• Last Update Posted (Actual): March 21, 2017
• Last Update Submitted That Met QC Criteria: February 13, 2017
• Last Verified: February 1, 2017

More Information

Terms related to this study

• Keywords: vision testing; perimetry; glaucoma; test variability
• Additional Relevant MeSH Terms: Eye Diseases; Ocular Hypertension; Glaucoma
• Other Study ID Numbers: C7098-R

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Undecided

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No