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A Novel Acuity Testing Method

Primary Purpose

Vision Disorder

Status
Completed
Phase
Locations
United States
Study Type
Observational
Intervention
Sponsored by
National Eye Institute (NEI)
About
Eligibility
Locations
Outcomes
Full info

About this trial

This is an observational trial for Vision Disorder focused on measuring Instrument Development, Psychophysical Methods, ETDRS, Computer-Based Methods, Validation Study, Visual Acuity, Vision Tests/Instrumentation, Psychophysics, Modified Binary Search, Visual Acuity Test

Eligibility Criteria

undefined - undefined (Child, Adult, Older Adult)All SexesDoes not accept healthy volunteers

INCLUSION CRITERIA: Subjects will include clinic patients selected with priority for those with poor visual acuity and based on maintaining smooth clinic functioning. Subjects will be classified into those with or without ocular disease, high refractive error, AMD, cataract, optic nerve abnormality, corneal abnormality, uveitis, glaucoma, other retinal/choroid abnormality, amblyopia, or a specified other ocular disease. Patients with low vision will be oversampled in order to test within a large range of possible end points. All subjects will have the ability to understand and sign an informed consent form obtained prior to enrollment. Enrolled participants will range in age from 7 years to 90 years. EXCLUSION CRITERIA: Illiteracy (inability to identify letters of the Latin alphabet) Children younger than 7, due to cognitive inability to undergo specific tests and procedures required in the protocol.

Sites / Locations

  • National Eye Institute (NEI)

Outcomes

Primary Outcome Measures

Secondary Outcome Measures

Full Information

First Posted
April 3, 2001
Last Updated
March 3, 2008
Sponsor
National Eye Institute (NEI)
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1. Study Identification

Unique Protocol Identification Number
NCT00013936
Brief Title
A Novel Acuity Testing Method
Official Title
A Novel Acuity Testing Method
Study Type
Observational

2. Study Status

Record Verification Date
October 2002
Overall Recruitment Status
Completed
Study Start Date
March 2001 (undefined)
Primary Completion Date
undefined (undefined)
Study Completion Date
October 2002 (undefined)

3. Sponsor/Collaborators

Name of the Sponsor
National Eye Institute (NEI)

4. Oversight

5. Study Description

Brief Summary
The purpose of this protocol is to develop a valid, reliable, better standardized, and more efficient test of visual acuity (ability to see fine details) for use in clinical trials. Recent improvements in computer video hardware permit calibration, characterization, and accurate rendering of eye-chart-quality letters. The computer can then be used to measure acuity. The modified binary search (MOBS) testing strategy is one method of computer-based testing. This study will compare the accuracy, precision, stability and utility of the MOBS technique with the eye chart method used in the National Eye Institute's Early Treatment for Diabetic Retinopathy Study (ETDRS). The ETDRS method is currently the gold standard for acuity testing in clinical trials. Study subjects will include NEI clinic patients between 7 and 90 years of age with or without eye disease. Eye diseases include poor visual acuity, age-related macular degeneration, cataract, optic nerve abnormality, corneal abnormality, uveitis, glaucoma, other retinal or choroid abnormality, amblyopia or other eye disease. Participants will have their vision tested in each eye using both the ETDRS eye chart method and the MOBS method. The ETDRS method will require subjects to read all the letters on the chart until they can no longer see the details. For the MOBS method, they will read a single letter at a time that will appear on the computer screen. After reading each letter, a new letter will be presented that is either bigger or smaller in size. After completing the last acuity test, participants will fill out a questionnaire regarding their preference for one test type over the other.
Detailed Description
The primary objective of the project is to develop a valid, reliable, better standardized and more efficient test of visual acuity for use in clinical trials. Accuracy, precision, stability, and utility of the test will be assessed for non-inferiority with Early Treatment for Diabetic Retinopathy Study (ETDRS) protocol, the gold standard for acuity testing in clinical trials. The experimental protocol (EVA-MOBS {Electronic Visual Acuity - Modified Binary Search}) utilizes a testing strategy that would appear to increase the efficiency and standardization of acuity threshold determination. A more efficient test is justified on the basis of reducing subject burden. Increased measurement efficiency may also reduce both subject- and tester-based bias, while allowing a better means to assess measurement stability through the collection of repeated measures data. As part of the standard eye examination, replicated visual acuity assessments will be made during regularly-scheduled Clinic visits. Up to 500 opportunistically-sampled subjects from the National Eye Institute will be tested both with the ETDRS and EVA-MOBS protocols over a 12 month study period. Similar testing will take place at two other institutions (Devers Eye Institute, Portland, OR; The Retina Foundation of the Southwest, Dallas, TX) and the data from all three institutions will be combined and analyzed at the JAEB Center (Tampa, FL). Subjects will range in age from 7 years to 90 years and will be classified by clinical diagnosis (normal, high refractive error, age-related macular degeneration, cataract, optic nerve abnormality, corneal abnormality, uveitis, glaucoma, retinal/choroid abnormality, amblyopia and other criteria). First, those with poor acuity will be oversampled by increasing the chance that they will be selected for this testing. Second, patients will only be selected for this extra testing if it will not seriously delay clinic operations on any given day. Order of acuity test type will be randomized. It is estimated that up to 10 patients per day can have this testing performed without compromising clinic operations. The experimental protocol runs on a Palm handheld that is used to provide instructions to the tester, record the subject's responses, and communicate with a PC/monitor at a test distance of 3 meters. Stimuli are high contrast black-and-white ETDRS letters presented on an ultra high resolution FD Trinitron monitor, that subtend 2.5 to 200 min of arc; each letter appears in isolation under equiluminant conditions, and is flanked with black bars to simulate visual crowding. Acuity scores will be compared, with the ETDRS score serving as the reference standard. Stability of the acuity estimates from the EVA-MOBS protocol will be assessed with data from repeated measures. A short questionnaire will be administered, following the last acuity test, to determine whether a test type preference exists. If results indicate that the protocol is well tolerated by clinical populations and that thresholds are accurate, precise, and stable, the method will be standardized for use in future trials. Use of stimuli to test visual resolution acuity, such as the Landolt-C, may subsequently be evaluated.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Vision Disorder
Keywords
Instrument Development, Psychophysical Methods, ETDRS, Computer-Based Methods, Validation Study, Visual Acuity, Vision Tests/Instrumentation, Psychophysics, Modified Binary Search, Visual Acuity Test

7. Study Design

Enrollment
500 (false)

10. Eligibility

Sex
All
Accepts Healthy Volunteers
No
Eligibility Criteria
INCLUSION CRITERIA: Subjects will include clinic patients selected with priority for those with poor visual acuity and based on maintaining smooth clinic functioning. Subjects will be classified into those with or without ocular disease, high refractive error, AMD, cataract, optic nerve abnormality, corneal abnormality, uveitis, glaucoma, other retinal/choroid abnormality, amblyopia, or a specified other ocular disease. Patients with low vision will be oversampled in order to test within a large range of possible end points. All subjects will have the ability to understand and sign an informed consent form obtained prior to enrollment. Enrolled participants will range in age from 7 years to 90 years. EXCLUSION CRITERIA: Illiteracy (inability to identify letters of the Latin alphabet) Children younger than 7, due to cognitive inability to undergo specific tests and procedures required in the protocol.
Facility Information:
Facility Name
National Eye Institute (NEI)
City
Bethesda
State/Province
Maryland
ZIP/Postal Code
20892
Country
United States

12. IPD Sharing Statement

Citations:
PubMed Identifier
9040475
Citation
Johnson CA, Samuels SJ. Screening for glaucomatous visual field loss with frequency-doubling perimetry. Invest Ophthalmol Vis Sci. 1997 Feb;38(2):413-25.
Results Reference
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PubMed Identifier
7091289
Citation
Ferris FL 3rd, Kassoff A, Bresnick GH, Bailey I. New visual acuity charts for clinical research. Am J Ophthalmol. 1982 Jul;94(1):91-6.
Results Reference
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A Novel Acuity Testing Method

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