Abstract:
Vision screening plays a key role in detecting childhood vision conditions. Uncorrected refractive error
is the leading cause of visual impairment in children and has been associated with reduced academic
performance. This thesis investigated the role of the current preschool vision screening programme in
detecting vision conditions, as well as the associations of vision conditions with reading parameters, in
New Zealand children.
Retrospective record reviews, analysis of population level data and comparison with international gold
standard vision screening protocols were used to assess the efficacy of the current preschool vision
screening programme. Additionally, standard optometric clinical techniques were used to complete
comprehensive eye examinations, along with assessment of reading ability and eye movement.
The current preschool vision screening programme achieved high overall coverage and testability.
However, a lower proportion of Māori and Pacific children and those living in high deprivation
communities received vision screening and follow-up care compared with their peers. Refractive error,
most commonly astigmatism (65-80% of cases), was present in up to one third of children. Up to 84%
of New Zealand children with ametropia did not have appropriate correction. While the current vision
screening programme was effective for detecting children with amblyopia risk factors, the addition of
autorefraction significantly improved its sensitivity for detecting significant refractive error (P = 0.01).
Children referred from preschool vision screening also achieved lower scores on a test of early literacy
compared with children who passed vision screening (P = 0.01). Poorer near VA and stereoacuity were
associated with reduced reading scores and eye movement patterns that were similar to those seen in
younger and less proficient readers.
Equity-based improvements are required to ensure detection and treatment of vision conditions in New
Zealand children through more appropriate screening targets and protocols, and improved access to
screening and follow-up eye care. In particular, children with vision conditions that may affect near
visual function and reading outcomes require referral for follow-up eye care. Improving screening and
access to eye care will improve equity by ensuring that all children have appropriate correction to
improve their health and educational outcomes.