Development of the veterans affairs (VA)
low vision (LV) vision functioning questionnaire (VFQ) to measure low
vision outcomes
T.R. Stelmack,1,7,8 J. Stelmack,2,7,8 J.P. Szlyk,1,8 R.W. Massof,3 P. Turco, 4 T. Williams,5 B.D. Wright6
VA Chicago Health Care System, West Side Division,1
Edward Hines VA Hospital Blind Rehabilitation Center,2 Johns Hopkins Wilmer Eye Institute,3
Mass Eye and Ear Infirmary,4 Deicke Center for Visual Rehabilitation,5
University of Chicago,6 Illinois College of Optometry,7 Department of Ophthalmology and Visual Science,
UIC8
Objective: Low vision services include counseling,
devices and strategies to help persons with vision loss enhance performance
of activities of daily living and increase their independence. However,
there is considerable variation in services provided ranging from comprehensive
blind rehabilitation to simply dispensing magnification devices in an
outpatient setting. The objective of this research is to develop and validate
an instrument that can be used to measure low vision outcomes from different
treatment protocols and service delivery systems.
Methods: 117 subjects with visual loss ranging
from mild impairment to total blindness were recruited from the Hines
Blind Center, West Side Division VICTORS, Deicke Center for Visual Rehabilitation
and the Mass Eye and Ear Infirmary. Interviews with patients and rehabilitation
staff, literature/clinical practice guideline reviews were conducted to
determine content of the new instrument, named VA LV VFQ. The field-test
version was administered to subjects by telephone before rehabilitation.
Analyses. The Rasch Rating Scale Model was
applied to evaluate measurement properties of the instrument.
Results. The map of persons and items and
analysis of fit statistics are reported for
the question on difficulty of performing daily activities. The separation
index is 6.97 for items and 3.91 for persons. Reliability is .98 for items
and .94 for persons.
Conclusions. Preliminary analysis demonstrates
content and construct validity as well as reliability of the VA LV VFQ.
Further data analysis including patient self-reports of difficulty performing
activities pre and post rehabilitation will be needed to refine the instrument.
The VA LV VFQ will contribute to the VA patient care mission by enabling
clinicians and administrators to better target individuals who will benefit
from low vision and blind rehabilitation programs.
Funding Acknowledgment: VA Rehabilitation
Research and Development #02086R, Illinois Society for Prevention of Blindness.