Page 186 - DISINVESTMENT AND IMPLEMENTATION OF VISION SCREENING TESTS BASED ON THEIR EFFECTIVENESS

CHAPTER 10
ENGLISH SUMMARY
Vision screening programmes in Europe are very diverse. Large differences exist in age, tests used and frequency of testing (number of tests). To make an inventory of the current vision screening programmes in Europe, we developed a questionnaire, which we presented to vision screening experts in 36 countries in Europe. In most European countries infants aged 0-4 months are examined with inspection of the eyes and red reflex testing. In most European countries children aged 6-30 months are screened with a combination of two or more of the following tests; inspection of the eyes, fixation, red reflex testing, Hirschberg test, Bruckner test, Cover test, pupillary reflexes, monocular pursuit and motility, but these tests are seldomly performed by orthoptists. In all European countries visual acuity (VA) in children is measured, but the age of the first measurement varies between three and seven years of age. In a third of countries VA is tested once, in one third twice and in one third more than two times (chapter 2).
In comparison with other vision screening programmes in Europe the Dutch vision screening programme stands out because of the number of screens performed. We modelled the effect of introduction, modification or disinvestment of a screening programme or its components with a micro-simulation model, with very detailed data from the RAMSES birth cohort study. The previous finding in the RAMSES birth cohort study that orthoptic tests at age 6-24 months yielded very few cases of amblyopia was confirmed by the micro-simulation model: The sensitivity and specificity of the entire screening programme was not appreciably affected by the omission of the 24 months screen (chapter 3).
The fact that few children with amblyopia are detected by orthoptic tests, performed by non-orthoptists, at 6-24 months of age gave us the incentive to perform semi- structured observations of all vision screening tests, as defined in the Child healthcare (CHC) screening guideline, performed by CHC physicians. Tests that were more often performed at a very young age, like the Hirschberg test and the fundus red reflex, were performed in accordance with the guideline. Preverbal vision screening consisting of (alternating) cover test, pupillary reflexes, monocular pursuit and motility were not performed according to the guideline. Visual acuity measurements in older children (36- 45 months) were, by and large, performed in accordance with the guideline (chapter 4).
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