Die effek van visieterapie op die okulêre motoriese beheer van 7– tot 8–jarige kinders met ontwikkelingskoördinasieversteuring (DCD)
Literature indicates 50% co–morbidity between Developmental Coordination Disorder (DCD) and attention deficit hyperactivity disorder (ADHD) (APA, 2000; Dewey et al., 2002; Kopp et al., 2010; Martin et al., 2006). According to the DSM–IV (APA, 2000), children who display criteria of both these conditions are diagnosed with Deficiencies in Attention Span, Motor Control and Perception (DAMP). Lefebvre and Reid (1998) and Pienaar (2008) report that coordination (hand–eye, footeye, and total body coordination), spatial orientation, and balance are influenced by the visual system and that motor deficiencies are often caused by poor ocular motor control functions (eye muscle functions). Concomitant with this, insufficient ocular motor control could lead directly to poor concentration and attention span, while it could lead indirectly to various behavioural problems (Barnett & Wiggs, 2011; Borsting et al., 2005; Iversen et al., 2006; Missiuna et al., 2011). Consequently, if any incorrect input of information by the visual system into the brain takes place, the neurological decision–making of the child, based on this information, will also be incorrect, which could lead to motor deficiencies, including ADHD and DCD (Barnett & Wiggs, 2011; Borsting et al., 2005; Dewey et al., 2002; Pienaar, 2008). Vision therapy is proffered as a possible intervention for the deficiencies mentioned that are concomitant with poor ocular motor control (Barrett, 2009; Cheatum & Hammond, 2000; Dudley & Vasché, 2010; Grisham, 1998; Hurst et al., 2006). The aim of the thesis was fourfold: to determine, firstly, what the effect of vision therapy would be on the ocular motor control of 7– to 8–year–old children with DCD and, secondly, what the effect of vision therapy would be on the DCD diagnoses 7– to 8–year–old children with DCD. The third aim was to determine what the effect of vision therapy would be on the ADHD and DCD status of 7– to 8–year–old children with DAMP and, lastly, whether vision therapy could bring about a significant improvement in the behaviour of children diagnosed with DAMP. Thirty–two children (20 boys and 12 girls) with a mean age of 7.98 years (sd±0.30) took part in the study. The Movement Assessment Battery for Children (MABC) (Henderson & Sugden, 1992) and the Movement Assessment Battery for Children Checklist (Henderson & Sugden, 1992) section five were used to determine children’s DCD status as well as their behavioural characteristics. The Taylor Hyperactivity Screening List (Lowenberg & Lucas, 1999) and Modified Conners Abbreviated Teacher (Lowenberg & Lucas, 1999) were used to classify children with ADHD. The Sensory Input Screening Measuring Instrument (Pyfer, 1988) and the Quick Neurological Screening Test II (QNST–II) (Mutti et al., 1998) test batteries were used to evaluate the children’s ocular motor control. A two–group pre–post–test crossover design was followed, with a retention test two years later to determine the effect of the vision therapy programme. The vision therapy was offered for 18 weeks, on an individual basis, by the researcher herself, once a week for 30 to 45 minutes during school hours, at the three different schools that took part in the study. For the data processing, the “Statistica for Windows 2010” computer program package was used (StatSoft, 2010). For descriptive purposes, data was, firstly, analysed using means (M), standard deviations (sd), and minimum and maximum values. Secondly, different repeated–measures–overtime analysis of variance (ANOVA) with a Bonferroni adaptation was used to determine the time effect of the intervention within the different groups. Lastly, dependent and independent t–testing were used to determine the pre–post–test differences of the vision therapy between the different groups. A p–value smaller than, or equal to, 0,05 was accepted as statistically significant, and a dvalue bigger than, or equal to, 0,5 was accepted as practically significant. The results showed that the percentage of ocular motor control problems in both groups before the start of the vision therapy varied between 6,25% and 93,75%. Vision therapy contributed to statistically significant (p≤0,05) improvement, which varied between 75% and 100% in visual pursuit, fixation, ocular alignment, and convergence–divergence. Both groups’ MABC total, fine motor skills, ball skills, and balance skills values, as well as the ocular motor control deviations, decreased statistically (p≤0,05) and practically (d?0,8) significantly on completion of the vision therapy, and this effect was still discernable two years later during the retention test. The results further showed that the DAMP group’s ADHD total decreased statistically significantly (p≤0,05) (51,14 to 23,07) after vision therapy had been received. Both the DAMP and DCD groups improved statistically (p≤0,05) and practically (d≤0,8) significantly as far as their MABC total and its three subsections were concerned after vision therapy had been received. The results also showed that the DAMP group showed a statistically significant (p≤0,05) higher mean value during the pre–test in section 5 (13,93 as opposed to 5,28) of the MABC checklist, which analyses behaviour, compared to the DCD group. The mean values of both groups for behaviour improved statistically significantly (p≤0,05) after vision therapy had been received, with a statistically significant bigger improvement in the behaviour of the DAMP group. On the basis of the above–mentioned results, it can be concluded that vision therapy does indeed have value and can be recommended for schoolage children diagnosed with DCD and DAMP, who also display poor ocular motor control and behavioural problems.
- Health Sciences