Page 179 - DISINVESTMENT AND IMPLEMENTATION OF VISION SCREENING TESTS BASED ON THEIR EFFECTIVENESS

CHC screening guideline. The semi-structured observations showed that tests that were performed at a very young age, like the Hirschberg test for the detection of strabismus, and the fundus red reflex, were performed in accordance with the CHC screening guideline and orthoptic practise. Preverbal vision screening consisting of more typical orthoptic tests, like the cover-uncover test, the alternating cover test and the eye motility tests, performed by non-orthoptists, were not performed according to the guideline and orthoptic practise. Eye motility was in most cases not tested in all directions of gaze and pupillary reflexes were often not tested because room lights could not be dimmed. In the majority of children the monocular pursuit movements were not tested. Monocular smooth pursuit movement at the age of 6-24 months is an indirect indicator of good VA of that eye. CHC physicians were often unaware of the true purpose of this test. The observations were presented to the participating CHC physicians and a majority of the CHC physicians stated that they indeed had difficulty with the performance and interpretation of the cover-uncover test, alternate- cover test, and monocular pursuit. Visual acuity measurements in children aged 36- 45 months were, by and large, performed in accordance with the guidelines and orthoptic and ophthalmologic practise. We concluded that the orthoptic tests are not suitable to be carried out by non-orthoptists in a screening setting.
From the results of the RAMSES study, the micro-simulation model and the on- site observations the impetus came for a disinvestment study. The Optimisation of Amblyopia Screening study (OVAS) was designed to assess whether the omission of orthoptic vision screening tests between age 6-24 months would have no significant negative impact on the severity and total cases of amblyopia detected. The study aimed to improve the cost-effectiveness of vision screening in the Netherlands without deterioration of the quality of care. Two sequential birth cohorts were recruited at the age of 6 months and followed up until the VA measurements at 45 months. The children were seen at general healthcare screening visits at 134 CHC centres of the CHC organization of Icare, serving the provinces of Drenthe, east Flevoland and mid Gelderland. At these general healthcare screening visits, children born July-December 2011 were vision screened at 6, 9, 14 and 24 months of age with inspection, pupillary reflexes, eye motility, Hirschberg test, cover test and monocular pursuit test. Children born January-June 2012 were vision screened at these general screening visits only in case of visually apparent abnormalities or a positive family history. Visual acuity was measured in all children at 36 and 45 months. Those children who had been referred by CHC physicians for diagnosis and treatment to an orthoptist or ophthalmologist were evaluated for cause and severity of amblyopia or other eye disorders.
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General discussion
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