Page 75 - DISINVESTMENT AND IMPLEMENTATION OF VISION SCREENING TESTS BASED ON THEIR EFFECTIVENESS

Semistructured observation of population-based eye screening in The Netherlands
INTRODUCTION
The first child healthcare (CHC) centre in the Netherlands was opened in 1901 to improve the general health of children.1,2 In 1960, measurement of visual acuity (VA) became part of the screening programme. It was suggested that the CHC centres could play an important role in the detection of amblyopia.3-4 Eye screening is now carried out by CHC nurses and CHC physicians, who are medical doctors trained to perform eye screening. They follow a one-day eye-screening course given by
a screening instructor, an orthoptist, which is repeated once every five years. The
eye screening programme in the Netherlands was extended in the 1980s to include examinations at the ages between 1 and 24 months, as the general belief was that the earlier amblyopia was discovered and treated, the better.5-6
The current eye screening programme consists of seven eye exams (at 1, 2, 3, 6–9, 14– 24, 36 and 45 months) as part of the population-based, comprehensive health, no-cost, voluntary screening and vaccination programmeme.5-6 At 1-4 months, eye screening includes inspection of the external structures of the eye, fundus red reflex, Hirschberg test, and pupillary reflex. At 6-24 months eye screening comprises inspection of the external structures of the eye, Hirschberg test, pupillary reflex, cover-uncover test, alternating-cover test, eye motility and monocular pursuit. Fundus red reflex is only done in children younger than four months of age. At 36 months VA is measured with the Amsterdam Picture Chart (APK) and at 45 months with the Landolt-C chart (Appendix 1).
The Rotterdam Amblyopia Screening Effectiveness Study (RAMSES), a prospective observational birth cohort study, showed that the vision screening programme was effective in detecting amblyopia.7-8 The RAMSES study showed that amblyopia caused only by refractive errors is not detected before the age that VA is measured and before that age most cases of amblyopia are detected by parents noticing strabismus.7 This has since been confirmed in the Optimization of Amblyopia Screening (OVAS) study, which compares two sequential birth cohorts, with and without eye screening tests, between 6 and 24 months of age.9-10 In its first report, concerning the omission of the screening at 6-9 months, there was little difference in referral rate and detection of amblyopia with or without eye screening at that age.9
These results raise the question why the detection rate of amblyopia with the current screening tests is low. One of the causes could be the use of orthoptic tests performed by non-orthoptists. In the current study we observed whether and how well these tests
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