Eccentric Viewing Training and Its Effect on the Reading Rates of Individuals with Absolute Central Scotomas: A Meta-analysis:

Structured abstract: Introduction: Eccentric viewing training has been a strategy, used by rehabilitation professionals, to help individuals with central vision loss move their eyes in such a way that they focus the incoming light on parts of the retina located away from the center area that has been damaged and improve visual functioning. A number of studies have shown that this type of training can be associated with improved reading rates. Method: A meta-analysis was conducted on data generated from 17 studies that reported the effect of appropriate magnification and eccentric viewing training on the reading rate of trainees with central scotomas. Results: Almost all eccentric viewing training methodologies were found to be associated with comparable final reading speeds, and no significant differences in final reading speed were found between eccentric viewing training methodologies with comparable age participants. A negative relationship between age and final reading speed was found through correlation analysis, and a correlation was found between visual acuity and the percentage of change in reading speed. Regression models using combinations of age, acuity, and treatment hours were found that could be used to predict the final reading rate using age and number of training hours. Discussion: This analysis provided no statistical basis to determine if one of the treatment protocols described in these studies was more effective in improving the reading rate than another, and there was quite a bit of variability in the protocols described. Implications for practice: Eccentric viewing is an effective way for individuals with central scotomas to improve the use of the vision that they have. Evidence from this meta-analysis suggests that a wide range of training protocols would be effective, and the personal preferences of the instructor and consumer can be given significant consideration during program planning. ********** Between 70 to 80% of what people with typical full vision learn comes through information gathered through vision (Li, 2004). The central part of the retina is the area through which information about details in the environment is typically acquired (Riordan-Eva & Whitcher, 2004). These details can be objects in the distance such as signs, people, and obstacles in one's path or objects more proximal such as food on a plate, faces of people in conversation, or information on the printed page. There are a number of diseases, however, that can damage the central part of the retina, leaving the affected person without vision in this area and the ability to discern detail (Bishop, 1996; Riordan-Eva & Whitcher, 2004). Before the 1960s, a popular belief was that individuals with low vision should refrain from using their vision because overuse could result in individuals using up or wearing out their vision. Subsequent research helped people understand that this was not the case (Hatlen, 2000). As a result, practitioners in the field of low vision began to investigate systematic methods to help individuals with low vision to maximize the effectiveness of the vision that they had. Eccentric viewing is one of the strategies that has been implemented over the years to help individuals who have a loss of central vision (Cheong, Lovie-Kitchen, & Bowers, 2005; Graessley & Kirby, 1996). Eccentric viewing training helps individuals learn to move their eyes in such a way that they focus the incoming light on parts of the retina located away from the central area that has been damaged (Holcomb & Goodrich, 1976). A number of studies have shown that this type of training can be associated with improved reading rates (Cheong et al., 2005; Crossland, Culham, Kabanarou, & Rubin, 2005; Frenesson, Jakobsson, & Nilsson, 1995; Deruaz et al., 2006). Many of these studies describe intervention protocols that include three basic steps: prescribing appropriate magnification, helping the individual identify effective eccentric viewing locations on their retina, followed by practice and often some type of follow-up support. …