Assessment of vision-related function in patients with age-related macular degeneration.
OBJECTIVE
To investigate the validity of the visual function index (VF-14) in assessing visual function in patients with age-related macular degeneration (AMD).


METHODS
Prospective noncomparative observational case series.


METHODS
One hundred fifty-nine consecutive patients attending a sole practitioner's academic retina-only clinic from May 1998 through August 1998 and from May 1999 through August 1999.


METHODS
Correlations were calculated between the VF-14 scores and the medical outcomes study 36-item short form (SF-36), weighted comorbidity scale, visual acuity and clinical AMD severity (stage), and vision self-assessment scales. Documentation of the severity of macular degeneration was performed by a sole examiner.


RESULTS
There was a moderately strong correlation between visual acuity and trouble with vision (r = 0.51), satisfaction with vision (r = -0.50), and overall quality of vision (r = -0.56). A strong correlation was noted between VF-14 score and patients' self-rating of amount of trouble with vision (r = -0.67), satisfaction with vision (r = 0.62), and overall quality of vision (r = 0.67). In comparison, correlations between SF-36 score and patients' self-rating of amount of trouble with vision, satisfaction with vision, and overall quality of vision ranged from r = 0.37 to r = -0.40. Linear regression analysis for the overall study population indicated that AMD severity was not an independently significant predictor of VF-14 score after adjusting for visual acuity. However, among patients with 20/20 vision in the better eye, AMD severity was an independently significant predictor of VF-14 score after adjusting for visual acuity in the worse eye.


CONCLUSIONS
The VF-14 exhibits a considerable degree of validity as a measure of functional impairment in patients with AMD. Age-related macular degeneration severity was an independently significant predictor of VF-14 score in the group of patients with 20/20 vision in the better eye, but this did not hold true for the overall study population. Age-related macular degeneration is associated with substantial impairment in reported visual function.
Mackenzie
Paul J
PJ
Division of Vitreo-Retinal Surgery, Department of Ophthalmology, University of British Columbia, Vancouver, BC, Canada.
Chang
Tom S
TS
Scott
Ingrid U
IU
Linder
Mark
M
Hay
Dawn
D
Feuer
William J
WJ
Chambers
Keith
K
D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006302:Health Services Research; D006304:Health Status; D006306:Health Surveys; D006801:Humans; D008268:Macular Degeneration; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011788:Quality of Life; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D014787:Vision Tests / Q000295:instrumentation; D014785:Vision, Ocular / Q000502:physiology*; D014792:Visual Acuity / Q000502:physiology