Abstract
Abstract: :
Purpose: Patients with age–related macular degeneration (AMD), who have little experience in using stand magnifiers (STM), often complain of difficulty with navigating the STM across the text when reading. Any assistance that can direct orientation to the place where they are reading may be beneficial in improving reading performance. The aim of this study was to investigate the effect of a simple line guide on the navigation and reading performance of AMD subjects using STMs. Methods: Twenty–nine subjects with AMD read short passages of text using their habitual STM with and without a temporary line guide attached. Magnifier movements (X, Y and Z) were recorded using a 3 SPACE Isotrak system. Reading time, magnifier movement strategies, navigation times and navigation errors were determined from the magnifier traces. A short questionnaire was used to quantify their habitual magnifier usage and perceived difficulty with page navigation; preference for reading with or without the line guide was also assessed. Results: Attachment of the line guide to the STM resulted in a small but significant decrease (10%) in reading rate (p<0.01), but no change in reading or navigation errors (p>0.05). For some subjects, the line guide improved the control of the vertical positioning of the STM when reading along a line (p=0.02), however the design of the guide made retracing the STM to the start of the next line more difficult. Fifty percent of subjects indicated a preference for reading with the line guide attached to their STM and there was a trend (p=0.09) towards those who preferred the line guide reporting greater habitual difficulties with STM manipulation. Conclusions: Despite limitations in design and only brief practice in using the line guide, fifty percent of subjects expressed a preference for the guide. This suggests that a line guide may be a useful temporary aid for AMD patients when a STM is first prescribed. Improvements to the design of the line guide and strategies to improve navigation performance are suggested.
Keywords: low vision • reading • clinical (human) or epidemiologic studies: systems/equipment/techniques