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Infant
hyperopia: detection, distribution, changes and correlates-outcomes from
the Cambridge infant screening programs.
Atkinson J, Braddick O, Nardini M, Anker S.
Visual Development Unit, University College London, London,
United Kingdom (JA, SA) and Department of Experimental Psychology, University
of Oxford, Oxford, United Kingdom (OB, MN).
PURPOSE.: To report on two population screening programs designed to detect
significant refractive errors in 8308 8- to 9-month-old
infants, examine the sequelae of infant hyperopia, and test whether early
partial spectacle correction improved visual outcome (strabismus and acuity).
The second program also examined whether infant hyperopia was associated
with developmental differences across various domains such as language,
cognition, attention, and visuomotor competences up to age 7 years. Linked
programs in six European countries assessed costs of infant refractive
screening. METHOD.: In the first program, screening included an orthoptic
examination and isotropic photorefraction, with cycloplegia. In the second
program we carried out the same screening procedure without cycloplegia.
Hyperopic infants (>/=+4 D) were followed up alongside an emmetropic
control group, with visual and developmental measures up to age 7 years,
and entered a controlled trial of partial spectacle correction. RESULTS.:
The second program showed that accommodative lag during photorefraction
with a target at 75 cm (focus >/=+1.5 D) was a marker for significant
hyperopia. In each program, prevalence of significant hyperopia at 9 to
11 months was around 5%; manifest strabismus was 0.3% at 9 months and
1.5 to 2.0% by school age. Infant hyperopia was associated with increased
strabismus and poor acuity at 4 years. Spectacle
wear by infant hyperopes produced better visual outcome than in uncorrected
infants, although an improvement in strabismus was found in the
first program only. The corrections did not affect emmetropization to
3.5 years; however, both corrected and uncorrected groups remained more
hyperopic than controls in the preschool years. The hyperopic group showed
poorer overall performance than controls between 1 and 7 years on visuoperceptual,
cognitive, motor, and attention tests, but showed no consistent differences
in early language or phonological awareness. Relative
cost estimates suggest that refractive screening programs can detect visual
problems in infancy at lower overall cost than surveillance in primary
care. CONCLUSIONS.: Photo/videorefraction can successfully screen
infants for refractive errors, with visual outcomes improved through early
refractive correction. Infant hyperopia is associated with mild delays
across many aspects of visuocognitive and visuomotor development. These
studies raise the possibility that infant refractive screening can identify
not only visual problems, but also potential developmental and learning
difficulties.
Optom
Vis Sci. 2007 Feb;84(2):84-96. |
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