Acceptability of childhood screening: a systematic narrative review.

OBJECTIVES: A systematic narrative literature review was undertaken to assess the acceptability of childhood screening interventions to identify factors to consider when planning or modifying childhood screening programs to maximize participation and uptake. STUDY DESIGN: This is a systematic narrative literature review. METHODS: Electronic databases were searched (MEDLINE, EMBASE, PsycINFO via Ovid, CINAHL, and Cochrane Library) to identify primary research studies that assessed screening acceptability. Studies were categorized using an existing theoretical framework of acceptability consisting of seven constructs: affective attitude, burden, ethicality, intervention coherence, opportunity costs, perceived effectiveness, and self-efficacy. A protocol was developed and registered with PROSPERO (registration no. CRD42018099763) RESULTS: The search identified 4529 studies, and 46 studies met the inclusion criteria. Most studies involved neonatal screening. Programs identified included newborn blood spot screening (n = 22), neonatal hearing screening (n = 13), Duchenne muscular dystrophy screening (n = 4), cystic fibrosis screening (n = 3), screening for congenital heart defects (n = 2), and others (n = 2). Most studies assessed more than one construct of acceptability. The most common constructs identified were affective attitude (how a parent feels about the program) and intervention coherence (parental understanding of the program, and/or the potential consequences of a confirmed diagnosis). CONCLUSIONS: The main acceptability component identified related to parental knowledge and understanding of the screening process, the testing procedure(s), and consent. The emotional impact of childhood screening mostly explored maternal anxiety. Further studies are needed to examine the acceptability of childhood screening across the wider family unit. When planning new (or refining existing) childhood screening programs, it is important to assess acceptability before implementation. This should include assessment of important issues such as information needs, timing of information, and when and where the screening should occur.

Children's Accommodation to a Variety of Targets - A Pilot Study.

BACKGROUND: Previous research indicates that a significant proportion of children underaccommodate at 1/3 m. Accommodation may vary with task demand, so children may accommodate appropriately if required, for example, when reading small print. This study explores the range of accommodative responses elicited in typical children, under naturalistic conditions, to a range of targets. METHOD: We identified 24 typically developing children from the University of Reading Child Database. Primary-school children attending UK Year 2 (age 6-7 years) or Year 6 (age 10-11 years) with minimum distance visual acuity of 0.200 logMAR and near visual acuity of 0.100 logMAR were recruited for participation. A remote haploscopic photorefractor was used to assess naturalistic, sustained, binocular accommodative responses to a variety of targets. At 33 cm, accommodative targets included individual letters, age-appropriate text in large print equivalent to early primary-school books, small N5 equivalent print, a visual search task ("Where's Wally?"), a clown picture containing a range of spatial frequencies, and a children's cartoon. Participants were given minimal instructions for task completion. The target presentation order was counterbalanced. The results reported in this study were obtained during a longer testing session involving different target types and fixation distances. RESULTS: The accommodative response observed with each target varied across participants to both the clown target and single letters of a size used in school reading books the accommodative responses were 2.4±0.48 D (range 0.85-2.97 D) and 2.47±0.37 D (range 1.48-3.09 D), respectively. The accommodative response to N5 print (3.06±0.52 D) was statistically better than all other targets other than the visual search and larger print tasks (P<0.05). CONCLUSIONS: Even to demanding N5 text, accommodation is variable between participants, but is better than that to less demanding targets. Tasks experienced by children in everyday or clinical situations will stimulate an unknown amount of accommodation for near fixation.

Development of the response AC/A ratio over the first year of life.

This study investigated the development of the link from accommodation to vergence in infants by occluding one eye thus removing binocular cues. Occluded adults continue to converge partially demonstrating that the accommodative drive to vergence (the AC/A link) and proximal cues are sufficient to drive vergence. For infants of all ages, AC/A ratios were found to be in the normal adult range. We conclude that infants can use monocular cues to drive vergence and that this occurs before the age when there is a substantial increase in the accuracy of oculomotor processes. There is flexibility in the developing visual system which is able to produce early vergence responses by relying upon alternative cues.

Variations in accommodation and convergence responses in a minimally controlled photorefractive setting.

PURPOSE: A remote haploscopic photorefractor, designed for assessment of accommodation and convergence in infants and clinical groups, was used to determine heterophoria accommodative convergence/accommodation (AC/A) ratios in normal naïve adults. These were compared with conventional clinical measures. METHODS: Twenty-one naïve subjects were used to compare occluded and unoccluded prism cover test responses with the remote haploscopic photorefractor using a text and picture target. RESULTS: Although luminance was generally low for both targets, binocular vergences were appropriate for target demand in both studies. Binocular accommodation showed greater lag for the highest target accommodative demand and the less demanding target. Occlusion not only reduced vergence response, but also frequently caused a marked reduction in accommodation, especially to the picture target. Normal mean AC/A values were found, but with wide variations between individual subjects. CONCLUSIONS: Although mean accommodation, vergence, and AC/A values were comparable with published data, we suggest that in these conditions using naïve subjects, accommodation is frequently inaccurate, especially on occlusion, without concomitant loss of vergence, at least at low light levels. Accommodative convergence may play a less important part in, and other cues contribute more to, the near reflex than has been previously suggested.

The response to prism deviations in human infants.

Previous research has suggested that infants are unable to make a corrective eye movement in response to a small base-out prism placed in front of one eye before 14-16 weeks [1]. Three hypotheses have been proposed to explain this early inability, and each of these makes different predictions for the time of onset of a response to a larger prism. The first proposes that infants have a 'degraded sensory capacity' and so require a larger retinal disparity (difference in the position of the image on the retina of each eye) to stimulate disparity detectors [2]. This predicts that infants might respond at an earlier age than previously reported [1] when tested using a larger prism. The second hypothesis proposes that infants learn to respond to larger retinal disparities through practice with small disparities [3]. According to this theory, using a larger prism will not result in developmentally earlier responses, and may even delay the response. The third hypothesis proposes that the ability to respond to prismatic deviation depends on maturational factors indicated by the onset of stereopsis (the ability to detect depth in an image on the basis of retinal disparity cues only) [4] [5], predicting that the size of the prism is irrelevant. To differentiate between these hypotheses, we tested 192 infants ranging from 2 to 52 weeks of age using a larger prism. Results showed that 63% of infants of 5-8 weeks of age produced a corrective eye movement in response to placement of a prism in front of the eye when in the dark. Both the percentage of infants who produced a response, and the speed of the response, increased with age. These results suggest that infants can make corrective eye movements in response to large prismatic deviations before 14-16 weeks of age. This, in combination with other recent results [6], discounts previous hypotheses.

Compliance with first time spectacle wear in children under eight years of age.

An anonymous prospective survey was carried out of children under 8 years of age prescribed a first pair of spectacles from the Royal Berkshire Hospital between August 1995 and May 1996, focusing on compliance in relation to refractive error, visual status and social factors. One hundred and thirty-three children were surveyed. Mean compliance was high (79.5/100) and spectacles were well liked by most children. Improvement in vision had little or no relationship with compliance. Significant factors were fit and what friends said about the spectacles. Adverse comments were rare, especially in the younger children, but increased with age. In pre-school children spectacles did not appear to be the salient feature in negative social judgements that has been found to occur in adults.

Maternal observations of ocular alignment in infants.

Seventy-five infants of state-registered orthoptists were observed by their mothers from birth to at least 6 months of age, with particular attention paid to the nature of any deviations noticed in the first few weeks. Most of the infants showed brief periods of inaccurate vergence during the first 2 months, with a wide variation in the amount of deviation seen, despite going on to develop normal binocular single vision. Most deviations were transient, unilateral, alternating esodeviations. There was a statistically significant relationship between the time that deviations were noticed and the development of demonstrable binocular convergence. Few exodeviations were found, contrasting with previous studies, and it is suggested that neonates are more likely to achieve binocular single vision when interacting with their mothers.