Development and validation of the Visual Function Battery for Children with Special Needs

Abstract

Children with special needs have physical, attentional, cognitive, learning, adaptive difficulties, or behavioral problems. These children often exhibit a high prevalence and various types of visual dysfunction, and may not be able to complete the regular visual assessment. Therefore, their visual difficulties would not be identified or would be underestimated. The aim of our study was to develop and validate a new visual function battery, the Visual Function Battery for Children with Special Needs (VFB-CSN), to meet the special needs and to quantify the heterogeneous visual characteristics and abilities of these children.

This was a scale development and validation study. The construct and item generation were based on the special needs of these children. The visual problems of these children are not limited to visual acuity. Thus, the VFB-CSN included the categories of visual reflex, ocular muscle balance, visual acuity, oculomotor, visual field, contrast sensitivity, color and form vision, and visual attention. The importance of the VFB-CSN was to introduce functional approaches to visual assessment. It is important for those children who could not cooperate with standardized visual tests. For example, in the contrast sensitivity subscale, we designed three functional items to assess visual responses to high or low contrast objects. In addition, in the visual acuity subscale, response to light or detection of different sizes of Styrofoam balls were included to assess the visual performance of children with severe or profound visual impairment. The item-weighted scoring system was established. The inter-rater reliability and multiple validities of the VFB-CSB were well evaluated.