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Different visual development: norms for visual acuity in children with Down's syndrome
Asma Aa Zahidi1, Valldeflors Vinuela-Navarro1,2, J Margaret Woodhouse1
1School of Optometry & Vision Sciences, Cardiff University, Cardiff, UK.
Insights
Children with Down syndrome have poorer vision than their peers. This study establishes visual acuity norms for this population, aiding early detection and intervention for visual development.
Area of Science:
- Ophthalmology
- Pediatrics
- Genetics
Background:
- Children with Down syndrome exhibit poorer visual acuity compared to typically developing children.
- Clinicians lack established visual norms for Down syndrome populations to identify atypical visual development.
- Early identification of visual issues is crucial for intervention in children with Down syndrome.
Purpose of the Study:
- To establish binocular visual acuity norms for children with Down syndrome.
- To provide clinicians with data for differentiating normal from anomalous visual development in this group.
- To highlight the visual disadvantage faced by children with Down syndrome.
Main Methods:
- Retrospective analysis of cross-sectional binocular visual acuity data from 159 children with Down syndrome (up to 12 years).
- Inclusion of longitudinal data from nine children for a comprehensive age-range assessment.
- Analysis of monocular acuity data from 69 children to assess inter-ocular differences and binocular summation.
Main Results:
- Binocular visual acuity in children with Down syndrome was consistently poorer from age three, stabilizing around 0.25 logMAR by age four.
- Inter-ocular acuity difference and binocular summation were found to be 0.06 logMAR.
- These findings are comparable to values reported in children without Down syndrome.
Conclusions:
- The study provides essential binocular acuity norms for eye-care practitioners treating children with Down syndrome.
- It underscores the visual disadvantage experienced by children with Down syndrome compared to their peers.
- Practitioners are urged to inform parents and educators about these visual differences, advocating for necessary classroom accommodations.
Background:
Visual acuity is known to be poorer in children with Down's syndrome than in age-matched controls. However, to date, clinicians do not have access to norms for children with Down's syndrome that allow differential discrimination of healthy from anomalous visual development in this population.
Methods:
The Down's Syndrome Vision Research Unit at Cardiff University has been monitoring visual development in a large cohort of children since 1992. Cross-sectional data on binocular visual acuity were retrospectively analysed for 159 children up to 12 years of age in order to establish binocular acuity norms. Longitudinal binocular acuity data were available for nine children who were seen regularly over the 12 years age-range. Monocular acuity was successfully recorded less often in the cohort, but analysis of scores for 69 children allowed assessment of inter-ocular acuity differences and binocular summation.
Results:
In comparison with published norms for the various acuity tests used, binocular acuity was consistently poorer in children with Down's syndrome from the age of three years and stabilised at around 0.25 logMAR from the age of four years. Inter-ocular acuity difference and binocular summation were both 0.06 logMAR, which is similar to the reported values in children without Down's syndrome.
Conclusions:
The study provides eye-care practitioners with the expected values for binocular acuity in children with Down's syndrome and demonstrates the visual disadvantage that children with Down's syndrome have when compared with their typically developing peers. The results emphasise the responsibility that practitioners have to notify parents and educators of the relatively poor vision of children with Down's syndrome, and the need for classroom modifications.
