A measure of handicap for low vision rehabilitation: the impact of vision impairment profile

Abstract

This study aims to further develop the Impact of Vision Impairment (IVI) profile into a practical, valid instrument for use in low vision rehabilitation. The IVI item pool was derived from focus groups of people with impaired vision, relevant content of existing quality of life questionnaires, and the administration of two trial versions. The second trial version of IVI was administered to 256 people who were vision impaired. Items were deleted if they were of little or no concern or were unable to be performed by most people, had moderate to high inter-item correlation, or did not contribute to a factor in the factor analysis. Two items were deleted due to floor and ceiling effects, 11 due to moderate to high inter-item correlation r≥ 0.6. None were removed as a result of factor analysis. The first three factors explained 59% of the variance. This reduced version of the IVI, a tool able to determine rehabilitation needs for people who are vision impaired, will now undergo its final validation procedures.