Reading aids for adults with low vision.

backgroundThe purpose of low vision rehabilitation is to allow people to resume or to continue to perform daily living tasks, reading being one of the most important. This is achieved by providing appropriate optical devices and special training in the use of residual vision and low vision aids, which range from simple optical magnifiers to high power video magnifiers.

objectivesThe objective of this review was to assess the effects of reading aids for adults with low vision. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group Trials Register) in The Cochrane Library, MEDLINE, EMBASE, SIGLE, LILACS, IndMed to July 2006 and the reference lists of relevant articles. We used the Science Citation Index to find articles that cited the included studies and contacted investigators and manufacturers of low vision aids. We handsearched the British Journal of Visual Impairment from 1983 to 1999 and the Journal of Visual Impairment and Blindness from 1976 to 1991. SELECTION CRITERIA: This review included randomised and quasi-randomised trials in which any device or aid used for reading had been compared to another device or aid in people aged 16 or over with low vision as defined by the study investigators. DATA COLLECTION AND ANALYSIS: Each author independently assessed trial quality and extracted data. MAIN

resultsEight small studies with a cross-over design (221 people overall) and one three parallel-arm study (243 participants) were included in the review. The cross-over studies evaluated various types of aids. The quality of the studies was unclear in most cases, especially concerning carry-over or period effects. In one study on 20 participants head-mounted electronic devices (four types) were worse than optical devices. We could not find any differences in comparisons among electronic devices when pooling 23 participants of two small studies. One study on 10 people found that overlay coloured filters were no better than a clear filter. A parallel-arm study including 243 patients with age-related macular degeneration found that custom or standard prism spectacles are not different from conventional near spectacles, but the estimated difference was not precise. AUTHORS'

conclusionsFurther research is needed on the comparison of different types of low vision aids. It will be also necessary to delineate patient's characteristics that predict performance with costly electronic devices as well as their sustained use in the long term compared to simpler and cheaper optical devices.