Cerebral visual dysfunction in prematurely born children attending mainstream school

Motor-Based Application Process for Cerebral Visual Impairment-Related Questionnaires for School-Age Children with Cerebral Palsy

This study aims to examine the psychometric properties of questionnaires related to cerebral visual impairment (CVI) in school-age children with cerebral palsy (CP). Additionally, it proposes an application process based on motor functionality for occupational therapists. A total of 288 children with CP were recruited for the study and administered the CVI Motor Questionnaire (CVI-MQ). The children's daily visual performance was assessed using the CVI Inventory and the Functional Vision Questionnaire (FVQ) considering the children's ambulatory status. The FVQ and the two factors extracted from the CVI Inventory significantly predicted visual functioning. Specific questionnaires related to CVI, applied with gross motor function in mind, can be valuable tools for occupational therapists to assess daily visual performance.

Occupational Therapy Assessments of Cortical or Cerebral Visual Impairment: A Systematic Review

IMPORTANCE

Cortical or cerebral visual impairment (CVI), a leading cause of visual dysfunction in children across the globe, can result in delayed development of fine and gross motor skills, functional mobility, and socialization, which affects all areas of occupation. No assessments are recommended for occupational therapy practitioners working with children with CVI.

OBJECTIVE

To appraise the measurement properties and clinical utility of CVI assessments appropriate for use by occupational therapy practitioners.

DATA SOURCES

MEDLINE via PubMed, Scopus, and Web of Science.

STUDY SELECTION AND DATA COLLECTION

We followed the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) guidelines for systematic reviews of patient-reported outcome measures for relevant studies.

FINDINGS

A total of 590 records yielded 15 studies of the measurement properties of 12 assessment tools, 8 patient-reported outcome measures and 4 clinician-reported or performance-based outcome measures. We report on the quality of measurement properties of 10 of the 12 outcome measures. None had high-quality evidence of content validity, structural validity, or test-retest reliability. Most had indeterminate internal consistency as a result of a lack of confirmatory factor analysis. Three instruments demonstrated high quality and sufficient construct validity.

CONCLUSIONS AND RELEVANCE

On the basis of the COSMIN guidelines, all 12 outcome measures have the potential to be recommended but require further study before definitive recommendations can be made. What This Article Adds: This is the first systematic review of assessments of CVI feasible for use by occupational therapy practitioners. High-quality studies of measurement properties are lacking. Further examination of the measurement properties of outcome measures is required.

Childhood cerebral visual impairment subtype classification based on an extensive versus a limited test battery

Purpose

To classify CVI subtypes and compare the added value of an extensive test battery over a limited test battery in subtype classification of cerebral visual impairment (CVI) in children.

Methods

Seventy-five children with a clinical diagnosis of CVI (median [IQR] age: 9 [7-12] years) were identified from the medical records. The extensive test battery included visual acuity, contrast sensitivity, ocular alignment, eye movement analysis, visual field analysis, optic nerve head evaluation, and evaluation of visual perception. The limited test battery included visual acuity, contrast sensitivity, ocular alignment, and evaluation of visual perception. Principal component analysis (PCA) followed by cluster analysis was done, for both test batteries separately, to determine the optimum subtype classification for CVI.

Results

Fifty-one participants with an extensive test battery with mild to moderate visual impairment were included in the main analysis. This resulted in four CVI subtypes for the extensive test battery (subtle characteristics, higher-level visual function deficits, lower-level visual function deficits, and higher- and lower- level visual function deficits) and three CVI subtypes for the limited test battery (subtle characteristics, higher-level visual function deficits, and higher- and lower- level visual function deficits). There were significant differences between the subtypes for 9 out of 10 measures of the extensive and all 4 measures of the limited test battery (p < 0.05). The subtle characteristics subtype (extensive n = 19, limited n = 15) showed near normal lower and higher-level visual functions in both test batteries. The higher-level visual function deficits subtype (extensive n = 18, limited n = 24) showed near normal visual acuity combined with significant visual perceptual deficits in both test batteries; accompanied by visual pathways defects and abnormal eye movement behavior in the extensive test battery. The higher- and lower- level visual function deficits subtype (extensive n = 4, limited n = 12) showed both higher and lower-level visual function deficits in both test batteries, but application of the extensive test battery revealed additional visual pathways defects and abnormal eye movement behavior. The lower-level visual function deficits CVI subtype (extensive n = 10) was a new subtype identified by the extensive test battery. This subtype showed lower-level visual function deficits together with abnormal eye movement measures.

Conclusion

This data-driven study has provided meaningful CVI subtype classifications based on the outcomes of various key functional and structural measures in CVI diagnosis. Comparison of the extensive test battery to the limited test battery revealed the added value of an extensive test battery in classifying CVI. The outcomes of this study, therefore, have provided a new direction in the area of CVI classification.

Preterm birth accelerates the maturation of spontaneous and resting activity in the visual cortex

Prematurity is among the leading risks for poor neurocognitive outcomes. The brains of preterm infants show alterations in structure and electrical activity, but the underlying circuit mechanisms are unclear. To address this, we performed a cross-species study of the electrophysiological activity in the visual cortices of prematurely born infants and mice. Using electroencephalography (EEG) in a sample of healthy preterm (N = 29) and term (N = 28) infants, we found that the maturation of the aperiodic EEG component was accelerated in the preterm cohort, with a significantly flatter 1/f slope when compared to the term infants. The flatter slope was a result of decreased spectral power in the theta and alpha bands and was correlated with the degree of prematurity. To determine the circuit and cellular changes that potentially mediate the changes in 1/f slope after preterm birth, we used in vivo electrophysiology in preterm mice and found that, similar to infants, preterm birth results in a flattened 1/f slope. We analyzed neuronal activity in the visual cortex of preterm (N = 6) and term (N = 9) mice and found suppressed spontaneous firing of neurons. Using immunohistochemistry, we further found an accelerated maturation of inhibitory circuits. In both preterm mice and infants, the functional maturation of the cortex was accelerated, underscoring birth as a critical checkpoint in cortical maturation. Our study points to a potential mechanism of preterm birth-related changes in resting neural activity, highlighting the utility of a cross-species approach in studying the neural circuit mechanisms of preterm birth-related neurodevelopmental conditions.

Preterm birth accelerates the maturation of spontaneous and resting activity in the visual cortex

Prematurity is among the leading risks for poor neurocognitive outcomes. The brains of preterm infants show alterations in structure and electrical activity, but the underlying circuit mechanisms are unclear. To address this, we performed a cross-species study of the electrophysiological activity in the visual cortices of prematurely born infants and mice. Using electroencephalography (EEG) in a sample of healthy preterm (N=29) and term (N=28) infants, we found that the maturation of the aperiodic EEG component was accelerated in the preterm cohort, with a significantly flatter 1/f slope when compared to the term infants. The flatter slope was a result of decreased spectral power in the theta and alpha bands and was correlated with the degree of prematurity. To determine the circuit and cellular changes that potentially mediate the changes in 1/f slope after preterm birth, we used in vivo electrophysiology in preterm mice and found that, similar to infants, preterm birth results in a flattened 1/f slope. We analyzed neuronal activity in the visual cortex of preterm mice (N=6 preterm and 9 term mice) and found suppressed spontaneous firing of neurons. Using immunohistochemistry, we further found an accelerated maturation of inhibitory circuits. In both preterm mice and infants, the functional maturation of the cortex was accelerated, underscoring birth as a critical checkpoint in cortical maturation. Our study points to a potential mechanism of preterm birth-related changes in resting neural activity, highlighting the utility of a cross-species approach in studying the neural circuit mechanisms of preterm birth-related neurodevelopmental conditions.

[Formula: see text] Visual selective attention and visual search performance in children with CVI, ADHD, and Dyslexia: a scoping review

Visual selective attention refers to the selection of relevant visual elements in a scene whilst ignoring irrelevant visual elements. Visual Selective Attention Dysfunctions (VSAD) are prevalent in children with Cerebral Visual Impairment (CVI), Attention Deficit Hyperactivity Disorder (ADHD), and Dyslexia. An important issue in the pediatric neuropsychological practice is how to discriminate between the task performance of these populations. We conducted a scoping review of the literature on visual search performance (VSP) in children with CVI, ADHD, and Dyslexia, aged 6-12 years. After a systematic selection process, 35 studies were included. Results suggest that all patient groups have some degree of impaired VSP compared to typically developing children. Children with CVI tend to react slower and less accurately. VSP impairments in children with ADHD are characterized by poor accuracy rather than reaction time. Children with Dyslexia tend to be slower and less accurate, depending on stimulus type. Besides VSAD, it is argued that other neurocognitive mechanisms might influence VSP, such as speed-accuracy trade-off or an executive functioning deficit in ADHD and a phonological deficit in Dyslexia. This paper further discusses the differences and similarities in visual search performance between the groups. The sparse data in children with an official diagnosis of CVI and the technical inconclusive data on children with ADHD and Dyslexia demonstrate complexity of discriminating between these populations in clinical practice based on VSP. New and more quantitative VSP parameters, such as eye tracking-based measures, may contribute to a refined classification among CVI, ADHD, and Dyslexia.

Effectiveness of early spectacle intervention on visual outcomes in babies at risk of cerebral visual impairment: a parallel group, open-label, randomised clinical feasibility trial protocol

INTRODUCTION

Hypoaccommodation is common in children born prematurely and those with hypoxic ischaemic encephalopathy (HIE), with the potential to affect wider learning. These children are also at risk of longer-term cerebral visual impairment. It is also well recognised that early intervention for childhood visual pathology is essential, because neuroplasticity progressively diminishes during early life. This study aims to establish the feasibility and acceptability of conducting a randomised controlled trial to test the effectiveness of early near vision correction with spectacles in infancy, for babies, at risk of visual dysfunction.

METHODS AND ANALYSIS

This is a parallel group, open-label, randomised controlled (feasibility) study to assess visual outcomes in children with perinatal brain injury when prescribed near vision spectacles compared with the current standard care-waiting until a problem is detected. The study hypothesis is that accommodation, and possibly other aspects of vision, may be improved by intervening earlier with near vision glasses. Eligible infants (n=75, with either HIE or <29 weeks preterm) will be recruited and randomised to one of three arms, group A (no spectacles) and two intervention groups: B1 or B2. Infants in both intervention groups will be offered glasses with +3.00 DS added to the full cycloplegic refraction and prescribed for full time wear. Group B1 will get their first visit assessment and intervention at 8 weeks corrected gestational age (B1) and B2 at 16 weeks corrected gestational age. All infants will receive a complete visual and neurodevelopmental assessment at baseline and a follow-up visit at 3 and 6 months after the first visit.

ETHICS AND DISSEMINATION

The South-Central Oxford C Research Ethics Committee has approved the study. Members of the PPI committee will give advice on dissemination of results through peer-reviewed publications, conferences and societies.

TRIAL REGISTRATION NUMBER

ISRCTN14646770, NCT05048550, NIHR ref: PB-PG-0418-20006.

The Multidisciplinary Guidelines for Diagnosis and Referral in Cerebral Visual Impairment

Introduction

Cerebral visual impairment (CVI) is an important cause of visual impairment in western countries. Perinatal hypoxic-ischemic damage is the most frequent cause of CVI but CVI can also be the result of a genetic disorder. The majority of children with CVI have cerebral palsy and/or developmental delay. Early diagnosis is crucial; however, there is a need for consensus on evidence based diagnostic tools and referral criteria. The aim of this study is to develop guidelines for diagnosis and referral in CVI according to the grade method.

Patients and Methods

We developed the guidelines according to the GRADE method 5 searches on CVI (children, developmental age ≤ 18 years) were performed in the databases Medline, Embase, and Psychinfo, each with a distinct topic.

Results

Based on evidence articles were selected on five topics: 1. Medical history and CVI-questionnaires 23 (out of 1,007). 2. Ophthalmological and orthoptic assessment 37 (out of 816). 3. Neuropsychological assessment 5 (out of 716). 4. Neuroradiological evaluation and magnetic resonance imaging (MRI) 9 (out of 723). 5. Genetic assessment 5 (out of 458).

Conclusion

In medical history taking, prematurity low birth weight and APGAR (Appearance, Pulse, Grimace, Activity, Respiration) Scores (<5) are important. Different questionnaires are advised for children under the age of 3 years, older children and for specific risk groups (extremely preterm). In ophthalmological examination, eye movements, specially saccades, accommodation, crowding, contrast sensitivity and visual fields should be evaluated. OCT can show objective signs of trans-synaptic degeneration and abnormalities in fixation and saccades can be measured with eye tracking. Screening of visual perceptive functioning is recommended and can be directive for further assessment. MRI findings in CVI in Cerebral Palsy can be structured in five groups: Brain maldevelopment, white and gray matter lesions, postnatal lesions and a normal MRI. In children with CVI and periventricular leukomalacia, brain lesion severity correlates with visual function impairment. A differentiation can be made between cortical and subcortical damage and related visual function impairment. Additional assessments (neurological or genetic) can be necessary to complete the diagnosis of CVI and/or to reveal the etiology.

Neural correlates associated with impaired global motion perception in cerebral visual impairment (CVI)

•

Cerebral visual impairment (CVI) is associated with impaired global motion processing.

•

Mean motion coherence thresholds was higher in individuals with CVI.

•

fMRI responses in area hMT+ showed an aberrant response profile in CVI.

•

White matter tract reconstruction revealed cortico-cortical dysmyelination in CVI.

Cerebral visual impairment (CVI) is associated with a wide range of visual perceptual deficits including global motion processing. However, the underlying neurophysiological basis for these impairments remain poorly understood. We investigated global motion processing abilities in individuals with CVI compared to neurotypical controls using a combined behavioral and multi-modal neuroimaging approach. We found that CVI participants had a significantly higher mean motion coherence threshold (determined using a random dot kinematogram pattern simulating optic flow motion) compared to controls. Using functional magnetic resonance imaging (fMRI), we investigated activation response profiles in functionally defined early (i.e. primary visual cortex; area V1) and higher order (i.e. middle temporal cortex; area hMT+) stages of motion processing. In area V1, responses to increasing motion coherence were similar in both groups. However, in the CVI group, activation in area hMT+ was significantly reduced compared to controls, and consistent with a surround facilitation (rather than suppression) response profile. White matter tract reconstruction obtained from high angular resolution diffusion imaging (HARDI) revealed evidence of increased mean, axial, and radial diffusivities within cortico-cortical (i.e. V1-hMT+), but not thalamo-hMT+ connections. Overall, our results suggest that global motion processing deficits in CVI may be associated with impaired signal integration and segregation mechanisms, as well as white matter integrity at the level of area hMT+.

Higher Visual Function Deficits in Children With Cerebral Visual Impairment and Good Visual Acuity

In clinical practice Cerebral Visual Impairment (CVI) is typically diagnosed by observation of abnormal visually guided behaviors which indicate higher visual function deficits (HVFDs) suggesting abnormal brain development or brain damage in a child with a suitable clinical history. HVFDs can occur even in the presence of good visual acuity and may remain undiagnosed because the good visual acuity does not prompt further investigation. This leads to a lack of understanding of the child's visual perceptual difficulties. In a prospective study, we determined the spectrum of HVFDs in a group of children with history suggestive of brain damage or disruption of brain development and an independent diagnosis of CVI in comparison with typically developing children with a structured 51 question inventory, the Higher Visual Function Question Inventory (HVFQI-51) adapted from the Cerebral Vision Impairment Inventory, CVI-I. Here, we show that the HVFQI-51 can detect a range of HVFDs in children with CVI with good visual acuity and clearly distinguishes these children from typically developing children. HVFDs in our study group could mostly be attributed to dorsal stream visual processing dysfunction though the spectrum varied between children. We report on the inclusion of the "not applicable" response option in analysis providing a picture of HVFDs more in tune with the overall disability of each child. We also propose a subset of 11 questions (Top-11) which discriminate between children with CVI vs. behaviors seen in typical children: this provides both a potential screening tool for initial assessment of HVFDs and a measure of CVI-related impairment, and needs further validation in a secondary independent sample.

Motion Processing Deficits in Children With Cerebral Visual Impairment and Good Visual Acuity

Purpose

We sought to characterize neural motion processing deficits in children with cerebral visual impairment (CVI) who have good visual acuity using an objective, quantifiable method (steady-state visual evoked potentials [SSVEPs]).

Methods

We recorded SSVEPs in response to three types of visual motion – absolute motion and more complex relative and rotary motion, comparing them to form-related vernier and contour responses. We studied a group of 31 children with CVI diagnosed via detailed clinical examinations and 28 age-matched healthy controls.

Results

Using measurements made at the appropriate response harmonics of the stimulation frequency, we found significant deficits in cerebral processing of relative and rotary motion but not of absolute motion in children with CVI compared with healthy controls. Vernier acuity, in keeping with good recognition acuity in both groups, was not different, nor were contour-related form responses.

Conclusions

Deficits for complex motion but relative sparing of elementary motion and form-related signals suggests preferential damage to extra-striate visual motion areas in children with CVI. The fact that these preferential losses occur in the absence of significant acuity loss indicates that they are not secondary to reduced visual acuity, but rather are an independent vulnerability in CVI. These results corroborate parental and caregivers’ reports of difficulties with tasks that involve motion perception in children with CVI.

Cortical Visual Impairment in Childhood: 'Blindsight' and the Sprague Effect Revisited

The paper discusses and provides support for diverse processes of brain plasticity in visual function after damage in infancy and childhood in comparison with injury that occurs in the adult brain. We provide support and description of neuroplastic mechanisms in childhood that do not seemingly exist in the same way in the adult brain. Examples include the ability to foster the development of thalamocortical connectivities that can circumvent the lesion and reach their cortical destination in the occipital cortex as the developing brain is more efficient in building new connections. Supporting this claim is the fact that in those with central visual field defects we can note that the extrastriatal visual connectivities are greater when a lesion occurs earlier in life as opposed to in the neurologically mature adult. The result is a significantly more optimized system of visual and spatial exploration within the ‘blind’ field of view. The discussion is provided within the context of “blindsight” and the “Sprague Effect”.

Perceptual visual dysfunction in children - An Indian perspective

Perceptual visual dysfunction (PVD) comprises a group of vision disorders resulting from dysfunction of the posterior parietal and/or temporal lobes. Often, affected children have normal/near normal visual acuities and/or visual fields, but have difficulties in activities of daily living involving the use of vision. PVDs are known to be common among children with risk factors such as a history of prematurity and/or neurodevelopmental disorders. The inferior temporal lobes and ventral stream transform visual signals into perception, while the posterior parietal lobes and dorsal stream transform visual signals to non-consciously map the scene to guide action and facilitate attention. Dysfunction of these can lead to specific visual impairments that need to be identified during history taking, triggering ascertainment of further details by a structured inventory approach. Clinical tests to elicit dorsal and ventral stream visual dysfunctions have good specificity but low sensitivity. Neuropsychologists are rarely available in the developing world to perform detailed assessments, but there are a few tests that can be used by eye care professionals with some training. Optical coherence tomography (OCT) showing thinning of the ganglion cell layer and retinal nerve fiber layer is being explored as a potential tool for rapid assessment in the clinic. The behavioral outcomes of PVD can mimic psychological conditions including autism spectrum disorder, attention deficit hyperactivity disorder, specific learning disability, and intellectual impairment, and one needs to be aware of overlap among these differential diagnoses. A practical functional approach providing working solutions for each child's set of difficulties in day-to-day activities is needed.

Visual function subtyping in children with early-onset cerebral visual impairment

AIM

To develop a data-driven subgrouping method to identify and profile subtypes of early-onset childhood cerebral visual impairment (CVI).

METHOD

Sixty-three children with suspected or diagnosed congenital CVI were recruited (28 males, 35 females, median age=8y, range=5-16y). Cognitive, basic, and higher-order vision functions were assessed and quality of life, functional vision questionnaire, neurodevelopmental, and ophthalmological data were collected. Cluster analysis and other statistical analyses were undertaken to determine and validate the subgrouping.

RESULTS

Forty-three participants completing the full test battery were included in cluster analysis, revealing two subgroups. Group A1 (n=15) showed selective visual perception and visuomotor deficits. Group A2 (n=28) showed more severe and broader visual perception and visuomotor deficits, and variable visual acuity. A third, lower-functioning group, Group B (n=20), was differentiated and showed significant visual acuity reduction compared with Group A (p<0.001, V=0.69). External validation showed significant cooccurring ophthalmological (e.g. strabismus p<0.001, V=0.59) and motor impairment differences (χ² =16.26, p<0.001, V=0.51) between the three groups. All groups had lowered parent-reported quality of life and everyday functional vision.

INTERPRETATION

Statistical analyses revealed three subgroups with differentiated vision function characteristics on a gradient of severity. The subgrouping method provides the first steps in developing a novel classification system to underpin future clinical diagnostics and profiling of early-onset CVI.

WHAT THIS PAPER ADDS

Three data-driven subgroups of vision function deficits were identified. A similar severity gradient was shown in cooccurring cognitive and neurodevelopmental deficits. Reported quality of life and functional vision difficulties were low across all groups.

What assessments are currently used to investigate and diagnose cerebral visual impairment (CVI) in children? A systematic review

PURPOSE

Cerebral visual impairment (CVI) is the leading cause of childhood visual impairment in the developed world. Despite this, there are no agreed clinical guidelines for the investigation and diagnosis of the condition. Before development of such guidelines can commence, it is important to recognise which approaches are currently employed. This systematic review evaluated the literature to identify which methods of assessment are currently used to investigate and diagnose childhood CVI.

METHODS

Medline, Embase, CINAHL, Scopus and the Cochrane Library databases were systematically searched in January 2020 using defined search terms. Articles were included if they: (i) were research papers, conference abstracts or research protocols published in peer-reviewed scientific journals, or relevant textbooks; (ii) included a clinical investigation of CVI in children; (iii) provided an explanation or criteria to diagnose CVI and (iv) were specifically investigating cerebral/cortical visual impairment. Methods used to a) assess and b) diagnose CVI were extracted from included articles. 'Assessment scores' were assigned for each method employed by researchers to investigate and diagnose CVI to quantify and compare approaches between articles. A quality grading was also applied to each article.

RESULTS

Of 6454 identified articles, 45 met the inclusion criteria. From these, 10 categories of assessment utilised within included articles were identified: (1) Medical history, (2) Vision assessment/ophthalmologic examination, (3) Neuroimaging, (4) Visual behaviour and direct observation, (5) Structured history-taking, (6) Visual perception tests, (7) Ocular movement and posture assessment, (8) Intelligence/IQ assessment, (9) Clinical electrophysiology and (10) Neurodevelopmental tests. In terms of diagnostic criteria, the most commonly reported approach was one of exclusion, i.e., CVI was diagnosed when visual dysfunction could not be attributed to abnormalities detected in the anterior visual pathway.

CONCLUSION

There is a lack of common practice in the approaches used by clinicians to investigate and diagnose CVI in children. At present, a 'diagnosis of exclusion' remains the most common means to diagnose CVI. Development of clinical guidelines for assessment and diagnosis are necessary to ensure consistency in the diagnosis of CVI and the timely implementation of support to alleviate the impact of CVI on the child's daily living.

Hippocampal epigenetic and insulin-like growth factor alterations in noninvasive versus invasive mechanical ventilation in preterm lambs

BACKGROUND

The brain of chronically ventilated preterm human infants is vulnerable to collateral damage during invasive mechanical ventilation (IMV). Damage is manifest, in part, by learning and memory impairments, which are hippocampal functions. A molecular regulator of hippocampal development is insulin-like growth factor 1 (IGF1). A gentler ventilation strategy is noninvasive respiratory support (NRS). We tested the hypotheses that NRS leads to greater levels of IGF1 messenger RNA (mRNA) variants and distinct epigenetic profile along the IGF1 gene locus in the hippocampus compared to IMV.

METHODS

Preterm lambs were managed by NRS or IMV for 3 or 21 days. Isolated hippocampi were analyzed for IGF1 mRNA levels and splice variants for promoter 1 (P1), P2, and IGF1A and 1B, DNA methylation in P1 region, and histone covalent modifications along the gene locus.

RESULTS

NRS had significantly greater levels of IGF1 P1 (predominant transcript), and 1A and 1B mRNA variants compared to IMV at 3 or 21 days. NRS also led to more DNA methylation and greater occupancy of activating mark H3K4 trimethylation (H3K4me³), repressive mark H3K27me³, and elongation mark H3K36me³ compared to IMV.

CONCLUSIONS

NRS leads to distinct IGF1 mRNA variant levels and epigenetic profile in the hippocampus compared to IMV.

IMPACT

Our study shows that 3 or 21 days of NRS of preterm lambs leads to distinct IGF1 mRNA variant levels and epigenetic profile in the hippocampus compared to IMV. Preterm infant studies suggest that NRS leads to better neurodevelopmental outcomes later in life versus IMV. Also, duration of IMV is directly related to hippocampal damage; however, molecular players remain unknown. NRS, as a gentler mode of respiratory management of preterm neonates, may reduce damage to the immature hippocampus through an epigenetic mechanism.

Development of the Parental Questionnaire for Cerebral Visual Impairment in Children Younger than 72 Months

Background and Purpose

Cerebral visual impairment (CVI) is an underdiagnosed condition in children, and its assessment tools have focused on older children. We aimed to develop a parental questionnaire for cerebral visual impairment (PQCVI) for screening CVI in young children.

Methods

The PQCVI comprised 23 questions based on a modified version of Houliston and Dutton's questionnaire for older children. The PQCVI with neurocognitive function tests was applied to 201 child-parent pairs with typically developing children younger than 72 months (age 32.4±20.1 months, mean±standard deviation). The children were classified into six age groups. The normative data, cutoff scores, and internal reliability were assessed and item analysis was performed. We referred to the total score for all questions as the cerebral visual function (CVF) score.

Results

The normative data showed that the CVF score and the scores corresponding to ventral-stream and dorsal-stream visual functions plausibly increased with age. The scores rapidly reached 90% of their maximum values up to the age of 36 months, after which they increased slowly. Cronbach's alpha for all questions across all age groups was 0.97, showing excellent consistency. The item difficulty and item discrimination coefficients showed that the questions were generally adequate for this age stage.

Conclusions

The PQCVI items produced reliable responses in children younger than 72 months. The rapid increase in scores before the age of 3 years supports the importance of early identification of CVI. Following additional clinical verification, the PQCVI may be useful for CVI screening.

Clinical use of the Insight Inventory in cerebral visual impairment and the effectiveness of tailored habilitational strategies

AIM

To investigate the utility of the Insight Inventory (a structured clinical inventory completed by caregivers) for assessment of children with cerebral visual impairment; and to investigate effectiveness of tailored habilitational strategies derived from the responses to the Insight Inventory.

METHOD

Fifty-one eligible children (26 males, 25 females; mean age 9y 5mo, SD 3y, range 5-16y) were recruited from Great Ormond Street Hospital, London. They underwent baseline assessment including neuro-ophthalmological and neuropsychological evaluations, and parent- and child-reported ratings on a questionnaire-based measure of quality of life. Parents also completed the Insight Inventory. On the basis of responses to the Inventory, families received individualized habilitational strategies. Follow-up assessments 6 months later included repeating the Insight Inventory and quality of life questionnaires.

RESULTS

Correlations were found between the Insight Inventory and the Wechsler Intelligence Scale for Children, Fourth Edition, the Beery-Buktenica Test of Visual-Motor Integration, and the Benton Facial Recognition Test, suggesting that the Insight Inventory is an effective tool to estimate visual-perceptual difficulties. At 6 months follow-up, caregiver reports indicated significant improvements in the quality of life of children below the age of 12 years.

INTERPRETATION

The Insight Inventory is a simple questionnaire which covers practical aspects of cognitive visual function in everyday life. It provides in-depth information about the aspects that children struggle with. It can also guide programmes of individualized habilitation strategies, which may enhance the quality of life of younger children.

WHAT THIS PAPER ADDS

Questionnaire scores demonstrate biologically plausible correlations with formal neuropsychological tests of visual function. After administration of matched practical habilitational strategies, younger children showed improvement in quality of life and functional vision scores.

Visuoperceptual profiles of children using the Flemish cerebral visual impairment questionnaire

AIM

To investigate the underlying factor structure of the 46-item Flemish cerebral visual impairment (CVI) questionnaire, differentiate the factor scores of children with and without CVI, and examine the impact of comorbidities on factor scores.

METHOD

The records of 630 children (386 males, 244 females; median age 77mo; interquartile range 63-98mo) who visited the CVI clinic and the Centre for Developmental Disabilities at the University Hospitals of Leuven from 2001 to 2018 were reviewed systematically. Inclusion criteria included an up-to-date questionnaire, a definitive diagnosis, and clinical assessment.

RESULTS

Three hundred and forty-five children (179 with CVI [108 males, 71 females; median age 74mo; interquartile range 61-93mo] and 166 without CVI [110 males, 56 females; median age 88mo; interquartile range 70-107mo]) were included. An exploratory factor analysis resulted in a 5-factor (object and face processing impairments; visual (dis)interest; clutter and distance viewing impairments; moving in space impairments; and anxiety-related behaviours) biologically and clinically plausible model, which retained 35 items and explained 56% of the total variance. Mann-Whitney U tests indicated that factors 1 to 4 were significantly higher in children with CVI compared to children without CVI (p-values ranged from p<0.001 to p<0.05; effect sizes ranged from 0.11 to 0.33); factor 5 showed no differences. Autism, developmental coordination disorder, epilepsy, and cerebral palsy impacted factor scores.

INTERPRETATION

A 5-factor structure of the Flemish CVI questionnaire differentiates children with and without CVI. Comorbidities should be accounted for when researching CVI.

WHAT THIS PAPER ADDS

Cerebral visual impairment (CVI) is characterized by impaired object and face processing and impaired visual interest. CVI is also characterized by impaired clutter and distance viewing, and impaired moving in space. All children (with or without CVI) demonstrated anxiety-related behaviours. Autism affected object/face processing, whereas developmental coordination disorder, epilepsy, and cerebral palsy affected visual interest.

As-indicated versus routine vision screening of preterm children: a 17-year retrospective regional study

PURPOSE

To investigate outcomes of routine vision screening compared to as-indicated ophthalmological investigation of all children born preterm in a Danish region from 1997 to 2014.

METHODS

All children born preterm (gestation age < 32 weeks or birthweight < 1500 g) screened for retinopathy of prematurity (ROP) were divided into two groups. From 1997 to 2009, only children treated for ROP or referred for visual problems received ophthalmological investigation (as-indicated group). From 2010 to 2014, all ROP-screened infants were offered ophthalmological investigation at 6 months and 3 years of age (screening group).

RESULTS

A total of 560 children were included in the as-indicated period, 41 and 87 were referred for ophthalmological investigation at 6 months and 3 years, respectively. In the screening period, 295 children were included, 251 and 150 of whom underwent vision evaluation at 6 months and 3 years, respectively. Mean visual acuity was 4.1 cycles per degree with Teller acuity cards at 6 months and 0.78 decimal at 3 years. At 3 years, 2.7%(n = 11) in the as-indicated versus 3.5%(n = 10) screening group had visual acuity < 6/18 (p = 0.24). Cerebral palsy (n = 28) and epilepsy (n = 5) were significantly related to vision impairment (p = 0.001/0.006), while treated ROP was not (n = 13). Refractive error was common at 3 years (61%), especially astigmatism (50%). Gestational age, birthweight and ROP were not associated with vision impairment or refractive error.

CONCLUSION

Screening preterm children at 6 months and 3 years did not reveal more visually impaired children compared to examination when indicated.

Cerebral visual impairment captured with a structured history inventory in extremely preterm born children aged 6.5 years

PURPOSE

To investigate whether a questionnaire can identify cerebral visual impairment (CVI) in a group of 6.5-year-old children born extremely preterm (EPT) as accurately as direct assessments.

METHODS

This prospective population-based study included 120 children born before 27 weeks' gestational age (66 males; mean, 25.4 ± 1.0 weeks) and 97 full-term controls (56 males; mean, 39.9 ± 1.1 weeks) at the age of 6.5 years, as part of the Extremely Preterm Infants in Sweden Study (EXPRESS). A questionnaire for detection of CVI was evaluated and compared with visual, perceptual, and cognitive assessments.

RESULTS

Parents of children born EPT reported more CVI features than the parents of control children, with median sum scores of 25 (95% CI, 18.1-31.9) and 11 (95% CI, 8.8-13.2), respectively (P < 0.001), and a median difference of 14 (95% CI, 6.6-21.4). Low rates of reported CVI features were significantly associated with better results from direct assessments within the EPT group and with less pronounced differences compared to controls.

CONCLUSIONS

The questionnaire discriminated well between children born EPT and controls, and the scores were congruent with other evidence of visual, perceptual, and cognitive deficits. The easily used questionnaire compared favorably with direct assessment in identifying CVI in children born EPT and also provides valuable information to clinicians, and parents about the daily life problems associated with CVI.

Early intervention for children at risk of visual processing dysfunctions from 1 year of age: a randomized controlled trial protocol

Background

An increasing number of children are suffering from brain damage-related visual processing dysfunctions (VPD). There is currently a lack of evidence-based intervention methods that can be used early in development. We developed a visual intervention protocol suitable from 1 year of age. The protocol is structured, comprehensive and individually adaptive, and is paired with quantitative outcome assessments. Our aim is to investigate the effectiveness of this first visual intervention program for young children with (a risk of) VPD.

Methods

This is a single-blind, placebo-controlled trial that is embedded within standard clinical care. The study population consists of 100 children born very or extremely preterm (< 30 weeks) at 1 year of corrected age (CA), of whom 50% are expected to have VPD. First, children undergo a visual screening at 1 year CA. If they are classified as being at risk of VPD, they are referred to standard care, which involves an ophthalmic and visual function assessment and a (newly developed) visual intervention program. This program consists of a general protocol (standardized and similar for all children) and a supplement protocol (adapted to the specific needs of the child). Children are randomly allocated to an intervention group (starting upon inclusion at 1 year CA) or a control group (postponed: starting at 2 years CA). The control group will receive a placebo treatment. The effectiveness of early visual intervention will be examined with follow-up visual and neurocognitive assessments after 1 year (upon completion of the direct intervention) and after 2 years (upon completion of the postponed intervention).

Discussion

Through this randomized controlled trial we will establish the effectiveness of a new and early visual intervention program. Combining a general and supplement protocol enables both structured comparisons between participants and groups, and custom habilitation that is tailored to a child’s specific needs. The design ensures that all included children will benefit from participation by advancing the age at which they start receiving an intervention. We expect results to be applicable to the overall population of children with (a risk of) VPD early in life.

Trial registration

Netherlands Trial Register: NTR6952. Registered 19 January 2018.

Hemianopia and Features of Bálint Syndrome following Occipital Lobe Hemorrhage: Identification and Patient Understanding Have Aided Functional Improvement Years after Onset

Introduction. Cerebral visual impairment (CVI) can present around birth or any time thereafter. Homonymous hemianopia is a common feature. The concept that functional improvement is unattainable augurs against active management. Dorsal stream dysfunction (or Bálint syndrome when severe) results from bilateral posterior parietal dysfunction but may go undetected, especially in children. Case Presentation. At 16 the patient suffered spontaneous left occipital lobe brain hemorrhage from a ruptured arteriovenous malformation. This was surgically excised. Short lived right upper limb intermittent jerking, with additional left sided weakness, ensued. Anomalous EEG recordings, with right-sided bias, arose from the posterior temporoparietal area. A right homonymous hemianopia was evident. During the ensuing 17 years she experienced multiple complex difficulties, until, at a lecture describing how to identify and support children with CVI, she realized she herself had many of the difficulties described. Visual assessment identified hemianopia and dorsal stream dysfunction. Discussion. Following identification, characterization, and explanation of the impact of her visual difficulties, she both gained greater awareness of her visual difficulties and their impact and developed a range of strategies leading to functional improvement of her visual field loss and amelioration of her dorsal stream dysfunction, with great improvement in quality of life.

Is there consensus in defining childhood cerebral visual impairment? A systematic review of terminology and definitions

The childhood condition of visual difficulties caused by brain damage, commonly termed cortical or cerebral visual impairment (CVI), is well established but has no internationally accepted definition. Clarification of its core features is required to advance research and clinical practice. This systematic review aimed to identify the definitions of childhood CVI in the original scientific literature to describe and critically appraise a consensual definition of the condition. MEDLINE, EMBASE, PsychINFO, CINAHL and AMED databases were searched in January 2017. Studies were included if they (1) were published original research, (2) contained a childhood CVI sample, (3) contained a definition of CVI and (4) described their CVI identification/diagnostic method. Thematic analysis identified concepts within definitions and narrative synthesis was conducted. Of 1150 articles, 51 met inclusion criteria. Definitions were subdivided according to detail (descriptive definition, description not reaching definition status and diagnostic/operationalising criteria). Three themes concerning visual deficits, eye health and brain integrity were identified (each containing subthemes) and analysed individually across definitions. The most common themes were ‘visual impairment’ (n=20), ‘retrochiasmatic pathway damage’(n=13) and ‘normal/near normal eye health’ (n=15). The most consensual definition identified here may not be the best quality for advancing our understanding of CVI. We argue for the alternative definition: CVI is a verifiable visual dysfunction which cannot be attributed to disorders of the anterior visual pathways or any potentially co-occurring ocular impairment. We propose reporting guidelines to permit comparison across studies and increase the evidence base for more reliable clinical assessment and diagnosis.

A Validation of an Examination Protocol for Cerebral Visual Impairment Among Children in a Clinical Population in India

INTRODUCTION

Cerebral Visual Impairment (CVI) is a leading cause of vision impairment in developed and developing countries due to and increased survival of preterm and low birth weight infants. There are few data concerning the validity of protocols available to diagnose CVI.

AIM

This study aimed to document the face, content and construct validity of an assessment protocol namely, a 15-domain, Structured Clinical Question Inventory (SCQI), which is based on structured history taking and clinical examination, for the diagnosis of CVI in a clinical population of India.

MATERIALS AND METHODS

This study was a retro-spective chart analysis of all children below the age of 18years, referred to the CVI clinic of a tertiary care teaching hospital in Southern India from March 2011-Feb 2012. Clinical case-notes including the SCQI findings of all children referred to the clinic were reviewed. The data were extracted after Institutional Review Board approval.

STATISTICAL ANALYSIS

Pearson correlation coefficient, Cronbach's alpha and exploratory factor analysis were used to document the content and construct validity of the examination protocol.

RESULTS

A total of 342 children (35.7% male, 64.3% female), with a mean age of 3.8 years (range 0-17 years, the median was 3 years) were included in the study and their data were examined. The internal consistency of the SCQI was 0.93 suggesting it as an excellent tool to characterise and profile CVI and a 2-factor model (Dorsal Stream Dysfunction and Ventral Stream Dysfunction) based on a biologically plausible model explained 63% of the variance.

CONCLUSION

The results of using the SCQI affirm published data and endorse a theoretical construct similar across cultures. The potential diagnostic accuracy, reliability and utility of this measure for CVI needs to be studied further. The clinical use of a short version of the SCQI may be helpful to contribute to the identification of CVI, especially for middle and low-income countries.

Effect of prematurity and low birth weight in visual abilities and school performance

BACKGROUND

Prematurity and low birth weight are known risk factors for cognitive and developmental impairments, and school failure. Visual perceptual and visual motor skills seem to be among the most affected cognitive domains in these children.

AIMS

To assess the influence of prematurity and low birth weight in visual cognitive skills and school performance.

METHODS

We performed a prospective cohort study, which included 80 boys and girls in an age range from 5 to 13. Subjects were grouped by gestational age at birth (preterm, <37 weeks; term, 37-42 weeks) and birth weight (small for gestational age (SGA), <10th centile; appropriate weight for gestational age (AGA), ≥10th centile). Each child underwent full ophthalmologic assessment and standardized testing of visual cognitive abilities (Test of Visual Perceptual Skills and Test of Visual Analysis Skills). Parents completed a questionnaire on school performance in children.

RESULTS

Figure-ground skill and visual motor integration were significantly decreased in the preterm birth group, compared with term control subjects (figure-ground: 45.7 vs 66.5, p=0.012; visual motor integration, TVAS: (9.9 vs 11.8, p=0.018), while outcomes of visual memory (29.0 vs 47.7, p=0.012), form constancy (33.3 vs 52.8, p=0.019), figure-ground (37.4 vs 65.6, p=0.001), and visual closure (43.7 vs 62.6 p=0.016) testing were lower in the SGA (vs AGA) group. Visual cognitive difficulties corresponded with worse performance in mathematics (r=0.414, p=0.004) and reading (r=0.343, p=0.018).

CONCLUSION

Specific patterns of visual perceptual and visual motor deficits are displayed by children born preterm or SGA, which hinder mathematics and reading performance.

A functional approach to cerebral visual impairments in very preterm/very-low-birth-weight children

BACKGROUND

Cerebral visual impairment (CVI) is a major cause of visual impairment, with very preterm birth/very low birth weight (VP/VLBW) being a major risk factor. There is no generally accepted definition of CVI. This study aims to investigate the usefulness of an empirically-based functional definition of CVI.

METHODS

One-hundred-five VP/VLBW children and 67 controls participated. CVI was defined after comprehensive oculomotor, visual sensory and perceptive assessment, and validated against vision problems in daily life and in terms of intellectual, behavioral, emotional and social functioning, as well as use of therapeutic services.

RESULTS

Twenty-four per cent of the VP/VLBW children met criteria for CVI, compared to 7% of controls (P = 0.006, OR: 3.86, 95% CI: 1.40-10.70). VP/VLBW children with CVI had lower performance IQ, but not verbal IQ, than those without CVI. Visual problems in daily life were confirmed in VP/VLBW children classified with CVI. Additionally, difficulties in behavioral and social functioning were most prominent among VP/VLBW children with CVI.

CONCLUSION

In VP/VLBW children, CVI defined in terms of visual function deficits is accompanied by intellectual, behavioral, and social impairments, validating our operational definition of CVI. CVI might act as a marker for developmental problems in VP/VLBW children.

Impact of retinopathy of prematurity on ocular structures and visual functions

The preterm baby may develop ophthalmic sequelae which can be due to prematurity per se, due to retinopathy of prematurity (ROP) or due to neurological damage. Focusing on the former two, we discuss how in high-income countries the risk of sight-threatening ROP is largely confined to babies <1000 g birth weight (BW), whereas in low-income or middle-income countries babies exceeding 2500 g BW can be blinded. The effects of prematurity and ROP are presented as regional and global estimates of acute-phase ROP and the consequent mild/moderate and severe visual impairment. We discuss sequelae and how they affect the eye and its shape, strabismus and finally consider their impact on visual functions, including visual acuity, the visual field, colour vision and contrast sensitivity.