Assessment of visual contrast function and effects of citicoline treatment in children with visual impairment
Abstract: Purpose: The present studies address the questions if visual dysfunction in severely visually impaired children can be measured with contrast tests high or low, how it relates to their visual abilities assessed with behavioural methods and if visual function in these children can be improved by neuro-pharmacological treatment. Methods: Twenty children aged 6-16 years from the Al-Maktoom school for visually impaired children in Islamabad, Pakistan were included in the first study and 22 children aged 6-14 years in the second study. The children were divided into two different groups of visual impairment. One group with congenital cataract, late surgery and inadequate postoperative treatment, causing vision deprivation amblyopia (VDA), and the other group with mainly retinal and optic nerve disease causing peripheral visual impairment (PVI). The intension was to compare the results of visual assessment in the two groups as a basis for suitable interventions based on the type of visual dysfunction. Both high and low contrast visual acuity was assessed, using cardboard letter charts. Previous studies in children with visual handicap had shown that visual function assessment with these tests corresponded quite well with assessment of the functional ability of the children.In the second study, all children received an intramuscular injection of 1 g of citicoline for 10 consecutive days. Both high contrast and low contrast visual acuity was tested with methods described earlier. Acuity was measured at baselin e (day 1), on day 30 and on day 90. Such studies have not been performed in children with severe visual impairment and treatment effects of citicoline have not been examined. Results: The distance high contrast tests were generally not well correlated among themselves in either group, whereas the near vision and low contrast tests were better correlated in the VDA group than in the PVI group. The low contrast tests were well correlated amongst themselves in the VDA group. It was also noted that the group with VDA had better functional ability to cope with the tasks put to them. In the second study an improvement in visual acuity of children with VDA was seen mainly during the period up to 30 days after citicoline treatment, while the improvement in the children with PVI occurred during a longer period, up to 90 days. A decline in acuity after treatment was observed in 2/11 children with VDA and 3/11 children with PVI. Conclusion: For a broad evaluation of the visual capabilities of children with impaired vision it is suggested that the visual examination should include both high- and low-contrast tests and functional vision assessment. The results of this pilot study on Citicoline effects are encouraging but extended examinations are needed to determine treatment procedures for citicoline treatment of visual dysfunction in children with severe visual impairment.
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