Abstract
Purpose: :
The Visual Field Index (VFI) (Carl Zeiss Meditec, Dublin, CA) is a new global metric that represents the entire visual field as a single percentage of normal. It is based largely on the pattern deviation and weighs central points more than peripheral ones. We investigated whether the VFI is correlated with self-reported quality of life scores measured with the NEI VFQ-25 (VFQ).
Methods: :
80 subjects who were glaucoma suspects or who had chronic glaucoma whose visual fields were unaffected by any other condition and whose visual acuity was 20/40 or better in each eye were administered the VFQ. All subjects had recent and reliable SITA Standard 24-2 visual field tests. Correlations were calculated between VFQ sub-scales and the better eye’s VFI, Mean Deviation (MD), and Pattern Standard Deviation (PSD). Additionally, to determine the effect on the VFQ of the worse eye’s visual field, we calculated correlations between the VFQ and the average VFI, MD, and PSD.
Results: :
For the better eye, the average VFI, MD, and PSD was 93.3%, -3.38 dB, and 3.21 respectively, while for the average of both eyes average VFI, MD, and PSD was 89.3%, -4.62dB, and 4.45 respectively. Statistically significant correlations (p < .05) were found between the better eye VFI and the VFQ sub-scales general health (r = .201), general vision (r =.300), near acuity (r = .271), distance acuity (r = .559), social function (r = .241), mental health (r = .578), role difficulties (r = .493), dependency (r = .609), and peripheral vision (r = .301) but not with ocular pain (r = .118), and color vision (r = .135). The driving sub-scale was eliminated as the majority of the subjects with lower VFIs had stopped driving. The correlations between VFQ sub-scales and better eye VFI were not significantly better than the correlation between VFQ sub-scales and average VFI, better eye MD, better eye PSD, average MD, or average PSD.
Conclusions: :
VFI was significantly correlated with the majority of the VFQ sub-scales. Our results suggest that VFI may have the potential to be used as an indirect measure of functional disability in the management of chronic glaucoma.
Keywords: quality of life • visual fields