The purpose of this study was (a) to systematically organize an eccentric viewing training program based on Hangul that strengthens preferred retinal loci (PRL) for low-vision individuals with central scotomas, and (b) examine whether the program is effective in improving the reading speed, reading activities, and other activities of daily living (ADLs).
The participants were 2 low-vision individuals with central scotomas caused by macular degeneration or optic neuropathy. A single-subject A-B-A’ research design was used to examine the effect of eccentric viewing training. The research was conducted over 14 sessions, which included 3 sessions during a pretraining baseline period (A), 8 sessions during an intervention period (B), and 3 sessions in a posttraining baseline period (A’). During the B intervention period, computer software based on Hangul stimulation for eccentric viewing training was used according to the rapid serial visual presentation (RSVP) method. The Hangul stimuli used in restructuring the program were converted to match the characteristics of the stimuli used in each phase of the MagnaFlyer program with English-based stimuli produced to reinforce eccentric viewing. The training held 2 to 3 times a week for 30 minutes a day. To measure reading, participants were assessed based on their short- and long-sentence reading speed by applying self-paced reading and reading sentences with enlarged font after attending eccentric viewing training. Observer reliability in measuring reading speed was over 90%. Evaluation of the participants’ reading activities and other ADL functions was conducted using Canadian Occupational Performance Measure (COPM), Low Vision Quality of Life Questionnaire (LVQOL), Melbourne Low-Vision ADL Index (MLVAI), and Assessment of Motor and Process Skills (AMPS) twice: once each before and after training. The average of the reading speed and ADL function scores was visually analyzed using a graph.
Analysis of the data showed that participants’ reading speed increased in both short- and long-sentence reading compared to their pretraining baseline scores. Participants also improved in both reading methods: self-paced reading and sentence reading with enlarged font. Greater improvements in reading speed occurred in the early intervention sessions (Sessions 2？3). Reading speed showed constant growth after the 5th session, and participants retained gains in reading speed even after the end of training. A comparison of overall ADL function at pretraining and posttraining showed no significant change, although reading activities showed improvement.
The results suggest that eccentric viewing training based on Hangul is an effective intervention method for improving the reading skills of low-vision individuals with central scotomas. A training period of between 4 and 5 sessions is necessary to acquire eccentric viewing with determined PRL. There was also an increase in reading activities. However, we could not verify any effects on ADL function except reading activities. This study is significant in that it showed the applicability of eccentric viewing training to rehabilitation of low-vision individuals in Korea.