[Visual function in developmental dyslexia. Opthalmological and neuropsychological results].

BACKGROUND

We aimed to test children with developmental dyslexia for possible alterations of their spatial and visuoperceptual ability.

METHODS

A total of 31 children with developmental dyslexia were included in the study. All children underwent a complete ophthalmological and orthoptic examination. Neuropsychological testing was performed using the Visual Object and Space Perception Battery (VOSP) and the subtest "Gestalt Closure" of the Kaufman Assessment Battery for children. Even though the VOSP is validated and standardized for adults, no normal values for children exist thus far. Therefore, a sex- and age-matched control group was tested. In addition, the parents of the dyslectic children completed the Child Behavior Checklist for Ages 4-18 (CBCL/4-18).

RESULTS

All children presented normal ophthalmological and orthoptic findings. Performance in the VOSP subtests "progressive silhouettes test'" and "number location" was significantly reduced in dyslectic children when compared to controls ( p<0.0003 and p<0.046, respectively). There was also a tendency towards lower values in the subtest "position discrimination" ( p=0.07). In the other subtests no significant difference between dyslectic children and controls was observed. The results of the subtest "Gestalt Closure" of the K-ABC and the CBCL/4-18 were within normal ranges.

CONCLUSION

The study demonstrates that developmental dyslexia is not based on ocular deficits, but indicates possible disturbances of visual-spatial cognition and visual-spatial perception in dyslectic children.