Sustainability of the effect of optical intervention on the reading performance of children with dyslexia.

Background: Dyslexia is a learning disability associated with reading difficulties in children. Due to the potential of poor school outcomes interventions have been employed to help students with dyslexia read. This study was aimed at identifying the sustainability of the effect of combined Visual Tracking Magnifier (VTM) and Ministry of Education (MOE) interventions and MOE intervention alone on the reading performance of school children with dyslexia after discontinuation of intervention. Methods: This prospective, interventional study was conducted on primary school children with dyslexia aged 8 - 11 years. The participants underwent comprehensive ophthalmic and optometric examinations and were categorized into groups A, B, and C, comprising primary school children at level 1 or 2. Groups A and B received combined VTM and MOE interventions for 12 and 24 weeks, respectively, and group C received MOE intervention alone. The reading performance was assessed at baseline and 12, 24, and 36 weeks post-intervention. Results: Both components of the reading performance improved significantly for school children at both levels in all study groups (all P < 0.05). However, the reading performance improvement was only approximately 28% in group C and 38% - 50% in groups A and B. In group A, students at level 1 showed significantly improved reading speed from baseline to 12 weeks post-VTM intervention and reading rate from baseline to 24 weeks post-VTM intervention (both P < 0.05). Students at level 2 showed significantly improved reading speed and rate from baseline to 12 and 24 weeks post-VTM intervention (all P < 0.05). In group B, students at both levels showed significantly improved reading speed and rate from baseline to 24 and 36 weeks post-VTM intervention (all P < 0.05). Students at level 2 showed significantly improved reading speed 12 weeks after cessation of intervention (at 36 weeks post-VTM intervention) compared to 24 weeks post-VTM intervention (P < 0.05). The improvement remaining stable 12 weeks after discontinuation of intervention indicated a sustained effect. Conclusions: Combined or individual intervention improved the reading performance of school children with dyslexia at levels 1 and 2. However, combined intervention showed a better reading improvement effect. Improvement in the reading performance was maintained after discontinuation of the VTM intervention. Further interventional studies with a longer study period after discontinuation of this optical intervention are required to confirm the long-term sustainability of its positive effects on the reading performance of school children with dyslexia.