Availability of data for cost-effectiveness comparison of child vision and hearing screening programmes.

OBJECTIVE: For cost-effectiveness comparison of child vision and hearing screening programmes, methods and data should be available. We assessed the current state of data collection and its availability in Europe. METHODS: The EUSCREEN Questionnaire, conducted in 2017-2018, assessed paediatric vision and hearing screening programmes in 45 countries in Europe. For the current study, its items on data collection, monitoring and evaluation, and six of eleven items essential for cost-effectiveness analysis: prevalence, sensitivity, specificity, coverage, attendance and loss to follow-up, were reappraised with an additional questionnaire. RESULTS: The practice of data collection in vision screening was reported in 36% (N = 42) of countries and in hearing screening in 81% (N = 43); collected data were published in 12% and 35%, respectively. Procedures for quality assurance in vision screening were reported in 19% and in hearing screening in 26%, research of screening effectiveness in 43% and 47%, whereas cost-effectiveness analysis was performed in 12% for both. Data on prevalence of amblyopia were reported in 40% and of hearing loss in 77%, on sensitivity of screening tests in 17% and 14%, on their specificity in 19% and 21%, on coverage of screening in 40% and 84%, on attendance in 21% and 37%, and on loss to follow-up in 12% and 40%, respectively. CONCLUSIONS: Data collection is insufficient in hearing screening and even more so in vision screening: data essential for cost-effectiveness comparison could not be reported from most countries. When collection takes place, this is mostly at a local level for quality assurance or accountability, and data are often not accessible. The resulting inability to compare cost-effectiveness among screening programmes perpetuates their diversity and inefficiency.

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.

Implementation of paediatric vision screening in urban and rural areas in Cluj County, Romania.

BACKGROUND: In 2018 and 2019, paediatric vision screening was implemented in Cluj County, Romania, where universal paediatric vision screening does not yet exist. We report on the preparation and the first year of implementation. METHODS: Objectives, target population and screening protocol were defined. In cities, children were screened by kindergarten nurses. In rural areas, kindergartens have no nurses and children were screened by family doctors' nurses, initially at the doctors' offices, later also in rural kindergartens. CME-accredited training courses and treatment pathways were organised. Implementation was assessed through on-site observations, interviews, questionnaires and analysis of screening results of referred children. RESULTS: Out of 12,795 eligible four- and five-year-old children, 7,876 were screened in 2018. In the cities, kindergarten nurses screened most children without difficulties. In Cluj-Napoca 1.62x the average annual birth rate was screened and in the small cities 1.64x. In the rural areas, however, nurses of family doctors screened only 0.49x the birth rate. In 51 out of 75 rural communes, no screening took place in the first year. Of 118 rural family doctors' nurses, 51 had followed the course and 26 screened children. They screened only 41 children per nurse, on average, as compared to 80 in the small cities and 100 in Cluj-Napoca. Screening at rural kindergartens met with limited success. These are attended by few children because of low population density, parents working abroad or children being kept at home in case of bad weather and road conditions. CONCLUSIONS: Three times fewer children were screened in rural areas as compared to urban areas. Kindergartens in rural areas are too small to employ nurses and family doctors' nurses do not have easy access to many children and have competing healthcare priorities: there are 1.5x as many family doctors in urban areas as compared to rural areas. For nationwide scaling-up of vision screening, nurses should be enabled to screen a sufficient number of children in rural areas.

Instead of pulley bands, does retrobulbar fat keep the eye muscle bellies in place and thereby act like a pulley?

Extraocular muscle pulley bands were described by Tenon in 1805 as "faisceaux tendineux" acting as "poulies de renvoi." The Passive and Active Pulley Hypotheses propose that these connective-tissue bands between muscle and bony orbital rim limit vertical shift of the horizontal rectus muscle belly in up- and downgaze, caused by the muscle's tendency to assume the shortest path from origin to insertion. The band's attachment to the muscle moves 20 mm sagittally when the eye looks from 50° left to 50° right, however, impeding vertical muscle stabilization. Sliding of the muscle in a sleeve would permit sagittal movement, but four anatomical studies could not confirm that. The band would have to be elastic: We measured it after orbital exenteration and found it to be slack, however, and once extended, very stiff. Our research group in Amsterdam suggested in 1984 that the retrobulbar fat and its enveloping connective-tissue sheets including the intermuscular membrane keep muscle bellies in place. We compared horizontal-rectus-muscle positions in up- and down-gaze using frontal CTs through the posterior pole of the eye. The bellies stayed in place while, anteriorly, the tendons bent up- and downward. We also found that the paths of horizontal rectus muscles were curved outwards in horizontal CTs. We surmised that retrobulbar pressure in the fat, resulting from four rectus muscles pulling the eyeball into the orbit, is contained by rectus muscles and connective-tissue sheets and that the resulting tension in the sheets keeps the muscles in place. Years later we repeated the CT study in a Crouzon patient whose bony orbital rim was displaced 2cm posteriorly, preventing pulley-band fixation to the bone: No vertical shift of horizontal rectus muscle bellies occurred in up- and down-gaze. Finally, we developed a mathematical finite-element model of orbit, muscles, fat and eyeball to study whether fat with enveloping connective-tissue sheets could keep eye muscles in place. In simulated eye movements, the retrobulbar fat, with low elasticity as found in vivo, not only kept the eyeball in place but also horizontal rectus muscle bellies in up- and down-gaze and vertical recti in left- and right-gaze.

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.

GPR179 is required for depolarizing bipolar cell function and is mutated in autosomal-recessive complete congenital stationary night blindness.

Complete congenital stationary night blindness (cCSNB) is a clinically and genetically heterogeneous group of retinal disorders characterized by nonprogressive impairment of night vision, absence of the electroretinogram (ERG) b-wave, and variable degrees of involvement of other visual functions. We report here that mutations in GPR179, encoding an orphan G protein receptor, underlie a form of autosomal-recessive cCSNB. The Gpr179(nob5/nob5) mouse model was initially discovered by the absence of the ERG b-wave, a component that reflects depolarizing bipolar cell (DBC) function. We performed genetic mapping, followed by next-generation sequencing of the critical region and detected a large transposon-like DNA insertion in Gpr179. The involvement of GPR179 in DBC function was confirmed in zebrafish and humans. Functional knockdown of gpr179 in zebrafish led to a marked reduction in the amplitude of the ERG b-wave. Candidate gene analysis of GPR179 in DNA extracted from patients with cCSNB identified GPR179-inactivating mutations in two patients. We developed an antibody against mouse GPR179, which robustly labeled DBC dendritic terminals in wild-type mice. This labeling colocalized with the expression of GRM6 and was absent in Gpr179(nob5/nob5) mutant mice. Our results demonstrate that GPR179 plays a critical role in DBC signal transduction and expands our understanding of the mechanisms that mediate normal rod vision.

An observational study to quantify manual adjustments of the inspired oxygen fraction in extremely low birth weight infants.

AIM: To quantify manual fraction of inspired oxygen (FiO(2)) adjustments performed by caregivers in extremely low birth weight (ELBW; ≤1000 g) infants, in relation to oxygen saturation (SpO(2)) and bedside care. METHODS: In a single-centre study, FiO(2) , SpO(2) and alarm limits of ELBW infants were collected for 3 days continuously, while caregivers were filmed. A descriptive analysis, focused on manual FiO(2) adjustments, was performed. RESULTS: Twelve ELWB infants were included. Total recording time was 726 h. FiO(2) was increased 851 times and decreased 1309 times; median (range) step size was 5% (1% to 65%) and -3% (-1% to -65%), respectively. Wide variation of FiO(2) adjustments for equal levels of SpO(2) was observed in all included infants. One hundred and twenty-six of 136 FiO(2) adjustments with a step size ≥15% and 111 of 171 desaturations <70% were associated with medical or nursing procedures. When FiO(2) was >21%, alarm limits for SpO(2) were set according to protocol (88-94%) in 64% of the time. Within these periods, SpO(2) was >94% for 30% and <88% for 16% of the time. CONCLUSIONS: Manual FiO(2) adjustments varied widely in frequency and step size. Deep desaturations and large FiO(2) adjustments were associated with medical or nursing procedures. When large adjustments are really necessary, it will be challenging to implement them in an automatic adjustment device.