Abstract
Purpose::
To test the hypothesis that the National Eye Institute’s Visual Function Questionnaire-25 (NEI-VFQ-25) survey is a better instrument for assessing vision-related quality of life (VR-QOL) than visual acuity in patients with diabetic retinopathy. With the better instrument, differences in VR-QOL between patients with non-proliferative diabetic retinopathy (NPDR) versus proliferative diabetic retinopathy (PDR) will be assessed.
Methods::
A retrospective review of 109 patients examined at the University of Chicago Department of Ophthalmology Vitreoretinal Service was conducted (NPDR= 51 / PDR= 58). The 2 questionnaires directed to measure VRQOL [VFQ-25 and Vision Preference Value Scale (VPVS)] _were administered by telephone. Information that may act as co-variants to VRQOL was collected from patients and medical records. To determine if VFQ-25 was a better measure than visual acuity, Spearman correlation coefficients were calculated by comparing the subject’s VFQ-25 score and visual acuity to the VPVS. To determine why VFQ-25 was the better measure, partial correlation coefficients while controlling for other ocular co-morbidities were analyzed to determine which of 12 VFQ subscales correlated strongest with VPVS scores. Finally, comparisons were made in VFQ scores to assess differences in VRQOL between patients with NPDR and PDR.
Results::
The absolute Spearman correlation coefficient between VPVS and VFQ-25 scores was 0.44 (p<0.01) and between VPVS and visual acuity scores was 0.35 (p<0.01). The 5 out of 12 VFQ-25 subscales with the strongest partial correlation coefficient to Utility scores were Role Differences, Near Activities, Distance Activities, Mental Function and Peripheral Vision (p<0.05). There was a significant decrease in the mean scores of total VFQ, Role Differences, Near Activities, Distance Activities, Mental Function and Peripheral Vision subscales in patients with PDR versus NPDR.
Conclusions::
These data indicate that the VFQ-25 is a more accurate measure of VRQOL than visual acuity for patients with diabetic retinopathy. VFQ’s superiority lies in its ability to better incorporate mental and emotional aspects of diabetic retinopathy as well as visual function. Finally, there is a significant decrease in VR-QOL in subjects with PDR versus NPDR, particularly in the domains of mental, emotional and visual function.
Keywords: quality of life • diabetic retinopathy • clinical (human) or epidemiologic studies: biostatistics/epidemiology methodology