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S.J. Leat, J.E. Lovie–Kitchin; Low Vision and the Useful Field of View (UFOV) . Invest. Ophthalmol. Vis. Sci. 2005;46(13):4607.
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© ARVO (1962-2015); The Authors (2016-present)
Purpose: The aim of this study was to measure the Useful Field Of View (UFOV) in people with visual impairment and to compare the results with the visual field measured by conventional clinical methods and with other clinical measures of visual function. The Useful Field Of View (UFOV) indicates the efficiency with which information can be extracted from a cluttered scene and situations of divided attention, and as such may be more predictive of everyday function than standard visual field tests. Methods: UFOV was measured as per Sekuler and Ball (J Opt Soc Am. 1986; 3:864–867) but with a presentation time of 125 msecs. Thirty–six subjects with low vision in two age groups (20–40 and 60–80 years) took part plus 22 age–matched controls. High and low contrast logMAR visual acuity, contrast sensitivity with the Pelli–Robson test and the Melbourne Edge Test, and Humphrey threshold fields (SITA Fast 30–2) were also measured. Results: Firstly, our results confirm other studies, showing that the UFOV task becomes more difficult with age and more errors are made with increasing eccentricity. Next, for both the low vision and the older control group there was a strong effect of the presence of distractors (cluttered field), p<0.01, but no effect of the presence of a central task (divided attention). For the younger control group this effect of distractors was not found because of a floor effect. Subjects with low vision made significantly more errors on the UFOV test than controls (p<0.001), but once we corrected for visual field losses, this difference was no longer significant. The measures which predicted UFOV scores were age and visual fields (for UFOV without distractors), and age, visual fields and contrast sensitivity (for UFOV with distractors). Conclusions: Although the UFOV results in low vision subjects were predicted by standard visual field scores, UFOV errors increased in the presence of distractors (clutter). Thus, as for observers with normal vision, standard clinical visual field tests do not fully describe the difficulties that may be encountered by people with visual impairment during complex daily tasks undertaken in cluttered environments and with the multiple demands of everyday life.
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