Effectiveness of routine population-wide orthoptic preschool vision screening tests at age 6-24 months in the Netherlands.

PURPOSE: The effectiveness of preverbal orthoptic tests at age 6, 9, 14 and 24 months in population-wide screening was assessed. METHODS: Two consecutive birth cohorts at 134 centres were compared. At general health screening visits, children born July-December 2011 were vision screened four times between 6 and 24 months with inspection, pupillary reflexes, eye motility, Hirschberg, cover test and monocular pursuit. Children born January-June 2012 were vision screened at general screening visits only in case of visually apparent abnormalities or positive family history. After referral, cause and severity of amblyopia were determined. Visual acuity was measured in all children at 36 and 45 months. RESULTS: The control and intervention group comprised 5649 versus 5162 children. Amblyopia was diagnosed in 185 (3.3%) versus 159 children (3.1%), outside of screening in 21 (11.4%) versus 25 (15.7%). Between 6 and 24 months, 44 (23.8%) versus 27 (17%) (RR = 0.67 [95% CI 0.42, 1.09]) were referred and after visual acuity (VA) measurement 120 (64.9%) versus 107 (67.3%). Of 109 versus 108 children with refractive or bilateral amblyopia, 94 (86.2%) versus 92 (85.2%) were detected with VA measurements. Visual acuity of the amblyopic eye, after referral, was not significantly different between groups (p 0.896), nor was the time to amblyopia diagnosis (intention to screen [p 0.55]; per protocol [p 0.11]). CONCLUSION: The effectiveness of vision screening was not influenced by omission of orthoptic tests at general health screening at 6-24 months. Refractive and bilateral amblyopia were almost exclusively found by VA measurements.

Semistructured Observation of Population-based Eye Screening in The Netherlands.

BACKGROUND: In the Netherlands, youth-healthcare (YHC) physicians screen children 7 times for vision disorders between the ages of 1 and 60 months. Examination consists of inspection of the external structures of the eye, fundus red reflex, Hirschberg test, pupillary reflexes, cover-uncover test, alternating-cover test, eye motility, monocular pursuit, and, from 36 months onwards, visual acuity (VA). We observed how well these tests are done. METHODS: Screening test performance was assessed with semistructured observations. Two orthoptic students developed a semistructured observation form. In addition to extensive instructions from an orthoptist and YHC-physicians instructor, they attended 2 one-day courses for YHC physicians. Tests were assessed using criteria based on the Dutch Child Vision Screening Guideline version 2010 and the Dutch Manual for Orthoptic Examination. Type of chart, testing distance, and starting eye were recorded for VA measurements. The observations in the first week were done simultaneously by the two observers and checked for concordance. RESULTS: Concordance between the two observers was good. Twenty-five YHC physicians were observed during 100 days in total. Two physicians were excluded because they examined few children. The remaining 23 physicians examined 329 children, of whom 82 were aged 1-4 months, 157 aged 6-24 months, and 90 aged 36-45 months of age. Fundus red reflex was performed in 89% of children, Hirschberg test in 88%, pupillary reflexes in 14%, cover-uncover test in 65%, alternating-cover test in 62%, eye motility in 68%, monocular pursuit in 23%, and VA at 36-45 months in 94%. Forty-eight percent of cover-uncover tests, 36% of alternating-cover tests, and 7% of eye motility tests were performed correctly. VA was measured at 3 meters in 2%, others at 5 meters in accordance with the guideline. A picture chart was used instead of the Landolt-C at the age of 45 months in 23%. VA measurements were performed correctly in 89%, fundus red reflex in 89%, and Hirschberg test in 87%. CONCLUSION: Hirschberg test, fundus red reflex, and VA were adequately tested in most cases. Cover-uncover test, alternating-cover test, and eye motility were often performed inadequately. Pupillary reflexes were skipped often as room lights could not be dimmed.

Effect of omission of population-based eye screening at age 6-9 months in the Netherlands.

PURPOSE: To investigate omission of population-based eye screening at age 6-9 months in the Netherlands. METHODS: Prospective population-based consecutive birth cohort study was used. In two consecutive birth cohorts, children were eye screened at 1-2 and 3-4 months, but at general-health screening at 6-9 months, the second cohort was not eye screened, unless anything conspicuous was noted or in case of positive family history. Data were collected from screening records and anonymous questionnaires. Semi-structured daylong observations were made of physicians examining children aged 0-4 years, including children from the cohorts, by two orthoptic students. RESULTS: 58 of 6059 children (0.96%), in the screened, and 48 of 5482 children (0.88%) in the unscreened group were referred to orthoptist or ophthalmologist, mostly for observed strabismus. Amblyopia, all combined with strabismus, was diagnosed in ten screened (0.17%) versus six unscreened children (0.11%). Most physicians found preverbal examinations and decisions to refer difficult. The observations by orthoptic students revealed that cover test, pupillary reflexes, pursuit movements and eye motility were frequently performed inadequately, contrary to the Hirschberg test, at this age. CONCLUSION: The screened and unscreened group differed little regarding the number of children referred and found to have amblyopia. Referral was mostly based on observed strabismus.