Advances in the evaluation and management of cortical/cerebral visual impairment in children

The pattern of visual impairment in the spectrum of hypoxic ischemic encephalopathy

PURPOSE

This study aimed to evaluate the relationship between visual impairment, social maturity, and clinical severity of hypoxic-ischemic encephalopathy (HIE) in the Indian population.

METHODS

An observational study was conducted in children with HIE sequelae aged between 6 months and 5 years. Sixty diagnosed cases of perinatal HIE were recruited, with twenty children in each of clinical grades 1, 2, and 3 according to the Sarnat clinical staging. All children underwent cycloplegic refraction using atropine 1% eye ointment, visual Acuity (VA) testing by teller acuity cards (TAC), anterior and posterior segment examination, FLASH visual evoked response (VER), strabismus workup, and social maturity assessment using the vineland social maturity scale (VSMS).

RESULTS

Sixty children, including 14 preterm and 46 term infants, with a mean age of 26.11 ± 16.06 months were studied. Normal birth weight was observed in 54% of the cases, whereas 42% had low birth weight and 4% had very low birth weight. There was no statistically significant difference between birth weight and the clinical severity of HIE (P = 0.970). A significant relationship between VA and clinical severity (TAC- p < 0.0001) and between VA and social maturity was observed. Optic disc pallor was present in 85% of grade 3 HIE cases. Among the 37 children with strabismus, the convergent type was predominant (86.4%). Refractive error was comparable across all grades of HIE.

CONCLUSION

Visual impairment was significantly related to the clinical severity of HIE and had a negative impact on the social maturity of these children.

Cerebral/Cortical Visual Impairment Classification and Categorization Using Eye Tracking Measures of Oculomotor Function

Purpose

Cerebral/cortical visual impairment (CVI) is a leading cause of pediatric visual impairment and is frequently associated with abnormal ocular motility. Eye tracking has previously been used to characterize oculomotor function in CVI. The purpose of this study was to evaluate the utility of eye tracking in diagnosis, categorization, and prognostication of CVI.

Design

Prospective longitudinal study.

Participants

Thirty-nine children with CVI and 41 age-matched controls.

Methods

Children with CVI underwent 4 eye tracking sessions over 1 year, and age-matched controls completed 1 eye tracking session. Fixations and saccades were labeled by the eye tracking software and used to compute 9 oculomotor features. In children with CVI, unsupervised data-driven clustering analysis using these 9 features was performed to identify 3 CVI eye tracking oculomotor groups. Clinical and demographic characteristics of eye tracking oculomotor groups were compared.

Main Outcome Measures

(1) Area under the curve (AUC) for eye tracking oculomotor features in classifying patients with CVI and controls; (2) differences between 3 CVI eye tracking oculomotor groups on clinical and demographic characteristics; and (3) change in visual acuity (VA) over 1 year in 3 CVI eye tracking oculomotor groups.

Results

Six oculomotor features (fixation and saccade latency, frequency, and off-screen proportion) had an AUC ≥0.90 in classifying children with CVI and controls (P < 0.0001). Cerebral/cortical visual impairment eye tracking oculomotor groups had significantly different VA (P < 0.0001) and change in VA over 1 year (P = 0.049). Patients in group B, who had the greatest improvement in VA, were younger and had higher rates of term hypoxic ischemic encephalopathy.

Conclusions

Eye tracking measures of oculomotor function accurately distinguish between children with CVI and age-matched controls. Clustering analysis revealed 3 CVI eye tracking oculomotor groups with prognostic significance. Eye tracking shows promise as an objective, quantitative measure of oculomotor function in CVI that may in future be useful in both clinical practice (for longitudinal assessment, prognostication, and guiding individualized interventions) and research (as an outcome measure or method to stratify patients in clinical trials).

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Cerebral injury and retinopathy as risk factors for blindness in extremely preterm infants

OBJECTIVE

This study investigates whether and to what extent cerebral injury is associated with bilateral blindness in extremely preterm infants, which has been attributed mainly to retinopathy of prematurity (ROP).

DESIGN

Multicentre analysis of children born from 1994 to 2021 at gestational age 22 0/7 to 28 6/7 weeks with follow-up at 18-26 months. Logistic regression examined the adjusted association of bilateral blindness with severe ROP and/or cerebral injury among extremely preterm infants.

EXPOSURES

Severe ROP and cerebral injury, the latter defined as any of the following on cranial imaging: ventriculomegaly; blood/increased echogenicity in the parenchyma; cystic periventricular leukomalacia.

MAIN OUTCOME MEASURES

Bilateral blindness, defined as a follow-up examination meeting criteria of 'blind-some functional vision' or 'blind-no useful vision' in both eyes.

RESULTS

The 19 863 children included had a mean gestational age of 25.6±1.7 weeks, mean birth weight of 782±158 g and 213 (1%) had bilateral blindness. Multiplicative interaction between ROP and cerebral injury was statistically significant. For infants with only severe ROP (n=3130), odds of blindness were 8.14 times higher (95% CI 4.52 to 14.65), and for those with only cerebral injury (n=2836), odds were 8.38 times higher (95% CI 5.28 to 13.28), compared with the reference group without either condition. Risks were not synergistic for infants with both severe ROP and cerebral injury (n=1438, adjusted OR=28.7, 95% CI 16.0 to 51.7, p<0.0001).

CONCLUSIONS

In a group of extremely preterm infants, severe ROP and cerebral injury were equally important risk factors for blindness. Besides ROP, clinicians should consider cerebral injury as a cause of blindness in children born extremely preterm.

TRIAL REGISTRATION NUMBER

NCT00063063.

A school-based intervention to improve mental health outcomes for children with cerebral visual impairment (CVI): feasibility cluster randomised trial

BACKGROUND

Cerebral visual impairment (CVI) refers to brain-related vision difficulties, which are often undiagnosed and may lead to poor mental health outcomes. We have developed an intervention to improve mental health outcomes for affected children, and it requires evaluation. The aim of this study was to assess the feasibility of methods proposed for a future definitive cluster randomised trial.

METHODS

This 18-month study took place in South West England, UK, between 2019 and 2021 including a 6-month pause due to the COVID pandemic. Participants were children aged 7-10 years in mainstream primary schools and their teachers and parents. We recruited head teachers on behalf of their school. The intervention was a resource pack for teachers explaining about CVI, providing universal and targeted strategies to help children with CVI and the offer of CVI assessments at the local eye clinic. The control schools continued with usual practice. Our objectives were to evaluate the feasibility of recruitment and data collection, attrition, acceptability of the study methods and implementation of the intervention. We conducted a process evaluation including interviews and questionnaires.

RESULTS

We sent invitation letters to 297 schools, received responses to 6% and recruited 40% of these (7 schools, 1015 children). Parents of 36/1015 (3.5%) children opted out. Baseline data were collected from teachers for 94% children, and 91% children completed self-report questionnaires; parent-report questionnaires were returned for 19% of children. During the exceptional circumstance of the COVID pandemic, two schools left the study, and many children were not attending school, meaning follow-up data were received from 32% of children, 16% of teachers and 14% of parents. Interview data indicated that the intervention was acceptable, and teachers would have preferred on-site eye tests to the offer of a clinic appointment and a clear timetable for study events. Teachers in intervention schools reported expected changes in the children's and their own behaviour. There was some contamination between study arms.

CONCLUSIONS

A full-scale trial would be feasible, enhanced by insights from this feasibility trial, in non-pandemic times. Sharing these data with teachers, education policymakers and parents is planned to refine the design.

TRIAL REGISTRATION

ISRCTN13762177.

The relation between clutter and visual fatigue in children with cerebral visual impairment

PURPOSE

Cerebral visual impairment (CVI) is a brain-based condition which can be exacerbated by clutter. This study aimed to explore the relation between clutter and visual fatigue in children with CVI and evaluate the effectiveness of clutter algorithm metrics in assessing visual clutter in photographs of children's play areas and the relation to visual fatigue.

METHODS

Visual clutter was measured using algorithmic metrics, subjective observations by a clinical researcher (who also observed visual fatigue) and a Qualtrics survey.

RESULTS

Seventy-two children (mean performance age = 7 years 4 months) were included. Visual fatigue was present in over 90% of children. Results revealed a relation between clutter and visual fatigue observations (rs = 0.29; p = 0.01) and between visual clutter observations from researchers and Qualtrics participants (rs = 0.32; p = 0.02). Certain metrics were correlated with visual clutter observations (rs ranging from -0.30 to 0.51, p-values ranging from <0.001 to 0.03), but not with visual fatigue.

CONCLUSIONS

Children with CVI presented with visual fatigue, particularly in cluttered environments. Therefore, parents, caregivers, teachers and clinicians should be attentive to visual fatigue signs, as early recognition and intervention can help address the child's needs more effectively. Algorithms that effectively quantify visual clutter are valuable tools that can be integrated to enhance the assessment of clutter and its relation with visual fatigue to advance CVI research methodology. However, a clinician is required to assess visual fatigue and to obtain detailed information on environmental clutter, which algorithms alone may not fully capture. Finally, we recognise that visual fatigue and the impact of clutter should be integrated into psychoeducation and the comprehensive assessment of individuals with CVI.

Adaptive functioning and relationship to visual behavior in children with cerebral/cortical visual impairment

BACKGROUND

Cerebral/cortical visual impairment (CVI) is a leading cause of pediatric visual impairment in developed countries and is associated with neurologic conditions that may impair adaptive functioning or skills required to perform everyday tasks (eg, communication, socialization, and daily living skills). Adaptive behavior in children with CVI has not been systematically studied, and the relationship between visual function and adaptive function in CVI is unknown.

METHODS

We prospectively recruited 49 children with CVI (mean age, 4 ± 3 years). Adaptive behavior was evaluated using the Vineland Adaptive Behavior Scale, 3rd edition (VABS-III). Visual acuity was assessed by a pediatric neuro-ophthalmologist using the six-level Visual Behavior Scale (VBS). The relationship between VBS and VABS-III scores was assessed using a Spearman correlation coefficient and a multiple regression model to correct for age, sex, and neurologic and ophthalmologic comorbidities.

RESULTS

In our cohort, mean adaptive behavior scores in children with CVI were below the 1st percentile on all VABS-III domains and subdomains. Visual acuity, as assessed by VBS, was significantly associated with VABS-III total adaptive behavior composite score (P = 0.04), socialization (P = 0.03) domain, and interpersonal (P = 0.04), play and leisure (P = 0.04), and personal (P = 0.01) subdomains.

CONCLUSIONS

Children with CVI have significantly reduced adaptive functioning. Visual behavior is correlated with socialization and some daily living skills. Future longitudinal studies should evaluate whether adaptive functioning increases as visual acuity improves in children with CVI, which may have prognostic implications.

The development of a screener for Cerebral Visual Impairment

This study explored the secondary use of Luxembourg's school monitoring tool for a large-scale screening of Cerebral Visual Impairment (CVI)-related difficulties. 44 items, with and without time constraint, were developed, and pretested among 959 children. All children subsequently participated in an individual evaluation of higher-level visual processing (HLVP) measures related with CVI. A clinical outcome was attributed post hoc with 32 children being classified as having CVI-related difficulties. To explore the predictive power of the CVI items included in the monitoring, item responses were matched to the results of the individual HLVP assessment. Of all items, the untimed item targeting the combined functions of surface and rotation significantly distinguished group performances (<.05). To improve condition discrimination, different item combinations were tested. Sensitivity and specificity metrics were computed resulting in ranges of 37.5% - 81.3% and 27% - 88.8% respectively. The item combination with the highest sensitivity (81.3%) was retained considering a viable trade-off between sensitivity and specificity metrics. These results support the secondary use of an existing large-scale monitoring tool to screen for CVI-related difficulties in the beginning of elementary school, provided that additional sources of information are progressively implemented to strengthen the tool's predictive power.

Ophthalmic Outcomes in Children With Spina Bifida Myelomeningocele in Ireland

PURPOSE

To investigate the ophthalmic complications associated with spina bifida myelomeningocele (SBM) in Irish children and to evaluate the impact of spinal lesion levels and shunt status on visual outcomes.

METHODS

A retrospective audit was conducted on 129 children with SBM, examining visual acuity, refractive errors, strabismus, papilledema, optic atrophy, and cortical visual impairment (CVI). The median age of participants was 6.9 years (interquartile range [IQR] = 7.07), comprising 69 females (53.5%) and 60 males (46.5%). Data were analyzed using chi-square and Kruskal-Wallis tests to assess associations between spinal lesion levels, shunt status, and visual outcomes.

RESULTS

The majority of lesions were lumbar (60.47%), followed by sacral (20.16%), thoracic (18.60%), and occipital (0.78%). Ventriculoperitoneal shunts were present in 67.44% of participants. Most children had good visual acuity, with visual impairment observed in 18.2%. Significant refractive errors were present in 40.8% of cases, whereas strabismus was observed in 33.3% of patients, predominantly esotropia. Papilledema, optic atrophy, and CVI were present in 12.4%, 5.4%, and 4.7% of participants. Higher spinal lesion levels were significantly associated with worse visual acuity (P = .019), whereas ventriculoperitoneal shunt status was significantly associated with papilledema (P = .034) and significant refractive errors (P = .019). No significant associations were found for strabismus, optic atrophy, or CVI.

CONCLUSIONS

Ophthalmic complications such as refractive errors, strabismus, and visual impairment are common in children with SBM. The authors found that higher spinal lesions were associated with worse visual acuity. Shunt placement was also associated with a history of papilledema and higher rates of significant refractive error. [J Pediatr Ophthalmol Strabismus. 20XX;XX(X):XXX-XXX.].

Method for assessing visual saliency in children with cerebral/cortical visual impairment using generative artificial intelligence

Cerebral/cortical visual impairment (CVI) is a leading cause of pediatric visual impairment in the United States and other developed countries, and is increasingly diagnosed in developing nations due to improved care and survival of children who are born premature or have other risk factors for CVI. Despite this, there is currently no objective, standardized method to quantify the diverse visual impairments seen in children with CVI who are young and developmentally delayed. We propose a method that combines eye tracking and an image-based generative artificial intelligence (AI) model (SegCLIP) to assess higher- and lower-level visual characteristics in children with CVI. We will recruit 40 CVI participants (aged 12 months to 12 years) and 40 age-matched controls, who will watch a series of images on a monitor while eye gaze position is recorded using eye tracking. SegCLIP will be prompted to generate saliency maps for each of the images in the experimental protocol. The saliency maps (12 total) will highlight areas of interest that pertain to specific visual features, allowing for analysis of a range of individual visual characteristics. Eye tracking fixation maps will then be compared to the saliency maps to calculate fixation saliency values, which will be assigned based on the intensity of the pixel corresponding to the location of the fixation in the saliency map. Fixation saliency values will be compared between CVI and control participants. Fixation saliency values will also be correlated to corresponding scores on a functional vision assessment, the CVI Range-CR. We expect that fixation saliency values on visual characteristics that require higher-level processing will be significantly lower in CVI participants compared to controls, whereas fixation saliency values on lower-level visual characteristics will be similar or higher in CVI participants. Furthermore, we anticipate that fixation saliency values will be significantly correlated to scores on corresponding items on the CVI Range-CR. Together, these findings would suggest that AI-enabled saliency analysis using eye tracking can objectively quantify abnormalities of lower- and higher-order visual processing in children with CVI. This novel technique has the potential to guide individualized interventions and serve as an outcome measure in future clinical trials.

The effectiveness of an individualised and adaptive game-based rehabilitation, iVision, on visual perception in cerebral visual impairment: A triple-blind randomised controlled trial

BACKGROUND

Cerebral visual impairment (CVI) can negatively affect a child's functioning, emphasising the need for interventions to improve visual perception (VP), potentially translating into improved health-related quality of life (HRQOL).

AIMS

Assessing the effectiveness of an adaptive individualised game-based rehabilitation, iVision, on VP, visual function, functional vision, and HRQOL.

METHODS AND PROCEDURES

Seventy-three children with CVI (3-12 performance age) were randomised into the adaptive individualised or the non-adaptive non-individualised group (3 sessions/week; 12 weeks). Primary outcome was change score (post-intervention - pre-intervention) of the lowest VP dimension. Key secondary outcomes included change score (post-intervention - pre-intervention) of visual function (reaction time to fixation in a preferential looking eye-tracking paradigm), functional vision (success rate in the adapted virtual toy box paradigm; total Flemish CVI questionnaire score), HRQOL (total scale score of the paediatric quality of life inventory 4.0 child self-report), and the lowest VP dimension change score (short-term follow-up - pre-intervention).

OUTCOMES AND RESULTS

Both groups significantly improved on the primary outcome, maintaining at short-term. Between-group differences were not significant. No significant effect was found for other key secondary outcomes. Exploratory analyses revealed VP dimension improvements and clinically meaningful HRQOL improvements.

CONCLUSIONS AND IMPLICATIONS

Although children with CVI improved their VP and to some extent HRQOL, no differences were found between the groups.

Diagnosis and Care of Children With Cerebral/Cortical Visual Impairment: Clinical Report

Cerebral/cortical visual impairment (CVI) is a leading cause of pediatric visual impairment in nations with developed economies and is increasing in those with developing economies. Because vision is the predominant sense used for learning, delay in diagnosis of CVI can negatively affect education, making early detection and management important. The American Academy of Pediatrics has published the policy statement "Visual System Assessment in Infants, Children, and Young Adults by Pediatricians" and an accompanying clinical report that are based on identifying potential causes of ocular visual impairment in children. Yet, routine vision screening may not accurately identify the brain-based visual impairment in children with CVI. Moreover, children with CVI often have medical complexity with other neurocognitive impairments and serious medical conditions that can make the diagnosis of CVI more difficult. Strategies are necessary for early identification of CVI to promote early diagnosis and referral for vision services that may allow a child with CVI to engage more fully in school, activities of daily living, vocational pursuits, and recreational activities. Knowledge of the characteristics of CVI as well as risk factors for CVI will assist the pediatrician in identifying children with CVI. This clinical report is complementary to previous vision screening policies, allowing both ocular and brain-based visual impairments in children to be identified and addressed. Pediatricians, other primary care physicians, pediatric ophthalmologists, neurologists, and other specialized pediatric eye care clinicians can identify children with CVI and coordinate effective evaluation, diagnosis, and referrals for vision services for these children.

Special Commentary: Cerebral/Cortical Visual Impairment Working Definition: A Report from the National Institutes of Health CVI Workshop

Cerebral/cortical visual impairment (CVI), a brain-based condition, has emerged as a leading cause of pediatric visual impairment in the United States and other industrialized nations. The National Eye Institute (NEI) recognized CVI as a priority area for research as part of their 2021 NEI Vision for the Future Strategic Plan and partnered with the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the National Institute of Neurologic Disorders and Stroke within the National Institutes of Health (NIH) to sponsor a CVI Workshop in November 2023. A panel consisting of a group of clinicians with expertise in diagnosing CVI convened to draft a working definition for this condition. Five key elements were identified: (1) CVI encompasses a spectrum of visual impairments caused by an underlying brain abnormality that affects the development of visual processing pathways and is characterized by deficits in visual function and functional vision; (2) the visual dysfunction in CVI is greater than expected by any comorbid ocular conditions alone; (3) the visual dysfunction in CVI may manifest as lower-order or higher-order afferent visual deficits, or both, leading to characteristic behaviors in affected individuals; (4) although CVI may be comorbid with other neurodevelopmental disorders, CVI is not primarily a disorder of language, learning, or social communication; and (5) the underlying neurologic insult of the developing brain may go unrecognized or undiagnosed until later in life. Future work is needed to achieve consensus on nomenclature, diagnostic criteria, and strategies for early identification and intervention. The NIH is developing a CVI registry to collect relevant demographic and clinical data prospectively and longitudinally to help inform future research questions and to provide insight into considerations for future clinical trials in the field of CVI.

Rasch analysis and targeting assessment of the teach-CVI survey tool in a cohort of CVI patients

Purpose

Cerebral Visual Impairment (CVI) is the leading cause of pediatric visual impairment. Given the diversity of clinical presentations of CVI, we are interested in whether questionnaires appropriately target the spectrum CVI cases, specifically the Teach-CVI Screening Tool. Rasch analysis is a standard psychometric technique for assessing the targeting of questionnaire items, however this analysis technique has not yet been applied to this questionnaire.

Methods

We performed a retrospective review of clinical CVI cases from the NECO Center for Eye Care at Perkins School for the Blind from January 2016 to December 2022. Electronic medical records were reviewed to identify patients with an ICD-9 or ICD-10 code of CVI or other neurological visual impairment. Age, gender, diagnoses, visual acuity, contrast sensitivity, visual fields, ocular alignment, and Teach-CVI responses were collected. We applied the method of successive dichotomizations, a polytomous Rasch model, to estimate item measures and person measures from the survey. Targeting of questionnaire items to the sample population was explored by comparing estimated item measures to person measures. Multiple linear regression was used to determine which factors influence patient visual ability (i.e., Teach-CVI person measure).

Results

119 patient records were included, 54% of which were male. The mean age was 8.9 years (SD = 6.12) with a range of 0 to 33 years of age. Mean visual acuity was 0.46 logMAR (SD = 0.40), or 20/57. The majority of patients in the sample had a co-occurring visual disorder in addition to CVI (84%), the most frequent being strabismus (69.9%) or visual field loss (25.3%). Item measures ranged from -2.67 to 1.77 logits (SD = 0.76), with a mean of 0 logit by convention. Estimated person measures ranged from -2.19 to 3.08 logits (SD = 1.10) with a mean of -0.03 logit. The range of item measures covered 93.3% of the person measures, and all person measures, except one, were within one logit of an item measure. Visual measures were not statistically significantly associated with Teach-CVI person measures.

Conclusion

The findings from this study suggest that the Teach-CVI survey is well targeted and an appropriate patient reported outcome measure for CVI.

Spectrum of Visual Dysfunction Detected by a Novel Testing Protocol Within a Special School Eye Care Service

Introduction

Children with special educational needs are more likely to have vision problems than peers in mainstream education. Reports focus on visual acuity and refraction, overlooking visuoperceptual difficulties, including cerebral visual impairment. This article reports on the feasibility and outcomes of visual function testing performed during in-school visual assessments.

Method

A retrospective chart review was undertaken of children participating in a special school vision programme. The testing strategy included acuity, fields, contrast sensitivity, eye movements, accommodation, stereopsis, visual attention, refraction and a parent-completed questionnaire. The testing method was chosen based on the child's ability to engage with testing.

Results

78 cases were identified (mean age 9.6 years). Low vision (worse than 6/19) was identified in 31%. All six tests of visual function were completed by 44% (mean 5.1; range 2-6). The mean number of atypical responses was 1 (range 0-4). Almost half (49%) showed at least one atypical response, most commonly visual attention (35%) and 25% had atypical eye movements.

Discussion

Overall, only 20% of children in the special school setting demonstrated a normal response to each test they were able to complete. Acuity testing alone does not demonstrate the atypical visual function of a child with special needs. Using techniques which require minimal cognitive, speech or motor function, a range of visual functions can be elicited during in-school testing. This testing strategy has the advantage of demonstrating areas of visual (dys)function impacting on the child's ability to access learning which can be immediately fed back to teaching staff and carers.

Cerebral palsy in children: A clinical practice review

Cerebral palsy is a disorder characterized by abnormal tone, posture, and movement. In clinical practice, it is often useful to approach cerebral palsy based on the predominant motor system findings - spastic hemiplegia, spastic diplegia, spastic quadriplegia, extrapyramidal or dyskinetic, and ataxic. The prevalence of cerebral palsy is between 1.5 and 3 per 1,000 live births with higher percentage of cases in low to middle income countries and geographic regions. Pre-term birth and low birthweight are recognized as the most frequent risk factors for cerebral palsy; other risk factors include hypoxic-ischemic encephalopathy, maternal infections, and multiple gestation. In most cases of cerebral palsy, the initial injury to the brain occurs during early fetal brain development. Intracerebral hemorrhage and periventricular leukomalacia are the main pathologic findings found in preterm infants who develop spastic cerebral palsy. The diagnosis of cerebral palsy is primarily based on clinical findings. Early recognition of infants at risk for cerebral palsy as well as those with cerebral palsy is possible based on a combination of clinical history, use of standardized neuromotor assessment and findings on magnetic resonance imaging; however, in clinical practice, cerebral palsy is more reliably diagnosed by 2 years of age. Magnetic resonance imaging scan is indicated to delineate the extent of brain lesions and to identify congenital brain malformations. Genetic testing and tests for inborn errors of metabolism are indicated to identify specific disorders, especially treatable disorders. Because cerebral palsy is associated with multiple associated and secondary medical conditions, its management requires a sustained and consistent collaboration among multiple disciplines and specialties. With appropriate support, most children with cerebral palsy grow up to be adults with good functional abilities.

An evaluation of health-related quality of life and its relation with functional vision in children with cerebral visual impairment

BACKGROUND

Health-related Quality of Life (HRQOL) and its relation with functional vision is understudied in cerebral visual impairment (CVI).

AIMS

Characterising HRQOL, comparing child self- and parent proxy-reports, and exploring relations with functional vision.

METHODS AND PROCEDURES

Seventy-three children with CVI (n females = 33; n males = 40; Mean performance age = 7y2m) were included. HRQOL was measured with Pediatric Quality of Life Inventory (PedsQL) child self- and parent proxy-reports and compared using Wilcoxon signed-rank tests. Risk for impaired HRQOL was evaluated using cut-off scores. Parents scored functional vision using the Insight Questions Inventory and the Flemish CVI Questionnaire.

OUTCOMES AND RESULTS

61 % (self-reported) or 66 % of children (proxy-reported) were at-risk for impaired total HRQOL. Ratings were correlated (rs = 0.305; p = 0.013); however, children rated higher total HRQOL compared to parent-proxy (r = 0.382; p = 0.002). The Insight Questions Inventory and the PedsQL proxy-report were correlated (rp = -0.454; p < 0.001), the Flemish CVI Questionnaire was negligibly correlated (rp = -0.244; p = 0.041).

CONCLUSIONS AND IMPLICATIONS

HRQOL is reduced in CVI, and both child and parent perspectives are crucial. HRQOL and functional vision are intricately related, and impairment in one negatively affects the other.

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.

Successful treatment of cortical visual impairment in children using anti-amblyopia treatment despite the absence of amblyopia: a case report

BACKGROUND

Cortical visual impairment (CVI) is a verifiable visual dysfunction that cannot be attributed to disorders of the anterior visual pathways or any potentially co-occurring ocular impairment. Given the limited knowledge on the most effective interventions for visual impairment resulting from CVI, this case report provides valuable insights into an example of successful implementation of anti-amblyopia therapy in a patient with CVI.

CASE PRESENTATION

This case report presents a 5-year-old girl with CVI secondary to hypoxic-ischemic injury, resulting in visual impairment, dyspraxia, and abnormal visual evoked potential testing. The girl did not suffer from amblyopia, there was no evidence of relevant refractive errors or strabismus, so visual pathway damage was the cause of her visual deficit. Nevertheless, the patient underwent anti-amblyopia therapy and showed significant improvement in visual acuity after 12 months of treatment. The improvement, resulting from visual stimulation, was due to a good functional recovery by a better usage of the damaged visual pathways. The therapy included prescribing corrective glasses and implementing secondary occlusion of the better eye for 4 months, which was protracted for another 4 months, leading to further improvements in visual acuity.

CONCLUSIONS

The case report shows that addressing even minor refractive errors and implementing anti-amblyopia therapy can significantly improve vision in children with CVI, even without co-existing amblyopia. It also highlights the importance of early intervention and multidisciplinary rehabilitation in children with CVI, focusing on motor and cognitive skills. Additionally, it emphasizes the need for further research to establish evidence-based practice standards for improving vision in children with CVI.

Evaluating Atypical Gaze Patterns through Vision Models: The Case of Cortical Visual Impairment

A wide range of neurological and cognitive disorders exhibit distinct behavioral markers aside from their clinical manifestations. Cortical Visual Impairment (CVI) is a prime example of such conditions, resulting from damage to visual pathways in the brain, and adversely impacting low- and high-level visual function. The characteristics impacted by CVI are primarily described qualitatively, challenging the establishment of an objective, evidence-based measure of CVI severity. To study those characteristics, we propose to create visual saliency maps by adequately prompting deep vision models with attributes of clinical interest. After extracting saliency maps for a curated set of stimuli, we evaluate fixation traces on those from children with CVI through eye tracking technology. Our experiments reveal significant gaze markers that verify clinical knowledge and yield nuanced discriminability when compared to those of age-matched control subjects. Using deep learning to unveil atypical visual saliency is an important step toward establishing an eye-tracking signature for severe neurodevelopmental disorders, like CVI.

Comparison of Eye Tracking and Teller Acuity Cards for Visual Acuity Assessment in Pediatric Cortical/Cerebral Visual Impairment

PURPOSE

To compare eye tracking and Teller acuity cards (TAC) for assessment of visual acuity in children with cortical, or cerebral, visual impairment (CVI).

DESIGN

Reliability and validity study.

METHODS

We recruited 41 children with CVI from a single academic pediatric neuro-ophthalmology clinic. All children performed eye tracking to measure visual acuity, and 26 children completed TAC assessment by a masked examiner. Additionally, 2 pediatric neuro-ophthalmologists graded visual behavior using the 6-level Visual Behavior Scale (VBS). Eye tracking and TAC were performed at baseline and at 1 month. Test-retest reliability of eye tracking and TAC were assessed using the intraclass correlation coefficient (ICC). Eye tracking and TAC visual acuities were correlated with one another and VBS scores using the Spearman correlation coefficient.

RESULTS

Test-retest reliability was excellent for eye tracking measurement of visual acuity (ICC = 0.81, P < .0001). For pediatric CVI, TAC test-retest reliability was fair (ICC = 0.42, P = .04). There was a moderate correlation between eye tracking and TAC (r = 0.43, P = .03) and between TAC and VBS score (r = 0.50, P = .009), and a strong correlation between eye tracking grating acuity and VBS score (r = 0.72, P < .0001).

CONCLUSIONS

In our cohort of children with CVI, grating acuity measured by eye tracking demonstrated higher test-retest reliability and stronger correlation with pediatric neuro-ophthalmologic assessment of visual behavior than Teller acuity. Objective determination of gaze direction by an eye tracking camera may be more accurate than human assessment in this population. Future research is needed to determine the optimal methods of longitudinal assessment of visual function and functional vision in children with CVI.

Neurological and Visual Outcomes in Infants and Toddlers Following Therapeutic Hypothermia for Neonatal Hypoxic-Ischemic Encephalopathy

BACKGROUND

The majority of studies have investigated neurodevelopmental outcomes, whereas visual impairment is less explored in children with a history of neonatal (hypoxic-ischemic) encephalopathy. Our aim was to perform a detailed neurological and visual assessment and also to investigate the presence of cerebral visual impairment in infants and toddlers with neonatal encephalopathy.

METHODS

Thirty participants with a history of neonatal encephalopathy, who had been hospitalized for therapeutic hypothermia, underwent a detailed neurological examination at age five to 36 months. Age-matched, 30 healthy children were also enrolled as a control group. All children in the study and control groups received neurological and a comprehensive ophthalmologic examination, including visual field and visual acuity. Presence of cerebral visual impairment was also evaluated clinically.

RESULTS

Rates of cerebral palsy, severe motor impairment, cognitive impairment, epilepsy, and cerebral visual impairment were found to be 20%, 10%, 15.3%, 10%, and 20%, respectively. When compared with healthy controls, oculomotor functions, pupillary light response, refractive parameters, anterior/posterior segment examinations, ocular visual impairment rates, and last, visual acuities were found similar. However, we found a statistically significant increase in visual field defects in our study group.

CONCLUSIONS

It could be better to perform a comprehensive ophthalmologic examination including visual field, visual acuity, and oculomotor functions by a pediatric ophthalmologist to accurately diagnose neurovisual deficits in infants following therapeutic hypothermia. Early identification and rehabilitation of the visual deficits might improve the neurodevelopment in these children.

"It's like a guessing game all the time": parent insights on barriers, supports, and priorities for children with cortical visual impairment and complex communication needs

Parents of children with both cortical visual impairment (CVI) and complex communication needs offer unique perspectives on their children's journeys to receiving proper diagnoses, supports, and interventions, such as augmentative and alternative communication (AAC). This study explored the lived experiences, supports, and barriers identified by parents through a qualitative phenomenological approach. Nine parents of children with both CVI and complex communication needs were interviewed virtually. Results indicated five themes descriptive of the parents' experiences: Challenges Piecing Together a CVI Diagnosis; Dealing with Low Expectations of Others; Parents Empowered to Take Action; Guessing Game to Determine Appropriate AAC to Accommodate CVI; and Aligning Professional Practice with Parent Priorities. Whereas some of these themes echoed the experiences of parents of children with complex communication needs (such as those with cerebral palsy) who were not specifically diagnosed with CVI, other themes were unique to this set of parents including the uncertainty of AAC design and intervention given the challenges of CVI and the necessity of more than one way for children to communicate given their visual challenges. This study highlighted the dire need for continued investigation to determine effective AAC interventions for individuals with CVI.

Australian children with cerebral visual impairment: using what we know now to improve future approaches

PURPOSE

Little has been reported on Australian children with Cerebral Vision Impairment (CVI). This paper aims to present the outcome of an audit focussed on children with the primary diagnosis of CVI, using findings from the Australian Childhood Vision Impairment Register (ACVIR).

METHODS

Records on 132 children (49% girls, 51% boys) from ACVIR data gathered from both the child's parent/guardian and their eye health professional were reviewed. The child's demographics, level of vision impairment, birth history, diagnostic journey, secondary ocular diagnoses, comorbidities and low vision support were analyzed. Several correlations were investigated using a Kendall's tau-b analysis including the relationship between vision and age of diagnosis; level of vision and developmental delay; and age of suspicion of visual impairment and age of diagnosis.

RESULTS

The most common level of visual impairment was blindness (39%), and most children were suspected and diagnosed of visual impairment in the first 6 months of life. The majority of children were born full term (72%), weighing >2000gms (84%). Nearly half of the cohort of children (48%) had a secondary ocular diagnosis with 44% having nystagmus. The majority of children (80%) had additional health problems, and 85% of children had additional disabilities, with 79% having developmental delay.

CONCLUSION

While the findings of this audit cannot be generalized to a wider population of Australian children with CVI, the outcome encourages continued discussion on CVI, to explore comprehensive assessment approaches which facilitate timely and accurate diagnosis.

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.

An Evidence-Based Approach to Augmentative and Alternative Communication Design for Individuals With Cortical Visual Impairment

PURPOSE

This article highlights the contributions of three pillars of an evidence-based practice approach (service providers, researchers, and families/clients) in the development of a framework to offer a way forward for professionals, families, and technology companies to support optimal visual and communication outcomes of individuals with cortical visual impairment (CVI) who use augmentative and alternative communication (AAC). By providing available research findings as well as practical information and lived experiences, the article offers clinical considerations and design features that can lead to addressing the unique needs of these individuals.

METHOD

This article reviews literature concerning what is known about CVI and describes in detail and from multiple viewpoints important features required in AAC systems to support individuals with CVI and enable them to communicate effectively.

RESULTS

Components necessary for teams, communication partners, and AAC designers to optimize AAC system design in CVI are presented using external research evidence as internal evidence from lived experience to support their importance.

CONCLUSIONS

An AAC system design that is tailored to the unique visual processing characteristics in CVI is likely to promote positive communication outcomes. The presentation of the lived experience of an individual who has CVI themselves illustrates the need for individualized assessments and interventions that incorporate and reflect the research presented here.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.23902239.

Object identification in cerebral visual impairment characterized by gaze behavior and image saliency analysis

Individuals with cerebral visual impairment (CVI) have difficulties identifying common objects, especially when presented as cartoons or abstract images. In this study, participants were shown a series of images of ten common objects, each from five possible categories ranging from abstract black & white line drawings to color photographs. Fifty individuals with CVI and 50 neurotypical controls verbally identified each object and success rates and reaction times were collected. Visual gaze behavior was recorded using an eye tracker to quantify the extent of visual search area explored and number of fixations. A receiver operating characteristic (ROC) analysis was also carried out to compare the degree of alignment between the distribution of individual eye gaze patterns and image saliency features computed by the graph-based visual saliency (GBVS) model. Compared to controls, CVI participants showed significantly lower success rates and longer reaction times when identifying objects. In the CVI group, success rate improved moving from abstract black & white images to color photographs, suggesting that object form (as defined by outlines and contours) and color are important cues for correct identification. Eye tracking data revealed that the CVI group showed significantly greater visual search areas and number of fixations per image, and the distribution of eye gaze patterns in the CVI group was less aligned with the high saliency features of the image compared to controls. These results have important implications in helping to understand the complex profile of visual perceptual difficulties associated with CVI.

Altered neural oscillations underlying visuospatial processing in cerebral visual impairment

Visuospatial processing deficits are commonly observed in individuals with cerebral visual impairment, even in cases where visual acuity and visual field functions are intact. Cerebral visual impairment is a brain-based visual disorder associated with the maldevelopment of central visual pathways and structures. However, the neurophysiological basis underlying higher-order perceptual impairments in this condition has not been clearly identified, which in turn poses limits on developing rehabilitative interventions. Using combined eye tracking and EEG recordings, we assessed the profile and performance of visual search on a naturalistic virtual reality-based task. Participants with cerebral visual impairment and controls with neurotypical development were instructed to search, locate and fixate on a specific target placed among surrounding distractors at two levels of task difficulty. We analysed evoked (phase-locked) and induced (non-phase-locked) components of broadband (4-55 Hz) neural oscillations to uncover the neurophysiological basis of visuospatial processing. We found that visual search performance in cerebral visual impairment was impaired compared to controls (as indexed by outcomes of success rate, reaction time and gaze error). Analysis of neural oscillations revealed markedly reduced early-onset evoked theta [4-6 Hz] activity (within 0.5 s) regardless of task difficulty. Moreover, while induced alpha activity increased with task difficulty in controls, this modulation was absent in the cerebral visual impairment group identifying a potential neural correlate related to deficits with visual search and distractor suppression. Finally, cerebral visual impairment participants also showed a sustained induced gamma response [30-45 Hz]. We conclude that impaired visual search performance in cerebral visual impairment is associated with substantial alterations across a wide range of neural oscillation frequencies. This includes both evoked and induced components suggesting the involvement of feedforward and feedback processing as well as local and distributed levels of neural processing.

A Scoping Review of Intervention for Pediatric Cerebral Visual Impairment: Calling All Pediatric Occupational Therapists

Cerebral visual impairment is the leading cause of low vision in children, and functional gains can be achieved with intervention. To date there exists no evidence-based intervention protocol to guide rehabilitation therapists. This scoping review was conducted to synthesize the evidence currently available and explore current interventions in order to guide future research. This review identified five types of interventions for cerebral visual impairment; habilitation, visual stimulation, video game, color tent, and medical and also evidenced the need for standardized, objective measures of function for this population.

Reason-Based Recommendations From a Developmental Systems Approach for Students With Needs Across Functional Domains

PURPOSE

This tutorial aims to introduce school-based speech-language pathologists (SLPs) to developmental systems theory as a framework for considering interactions across functional domains, such as language, vision, and motor, for students with complex needs.

METHOD

This tutorial summarizes the current literature on developmental systems theory in its application to working with students who have needs in multiple domains of functioning in addition to communication. A hypothetical case of a student, James, with cerebral palsy, cortical visual impairment, and complex communication needs, is presented to illustrate the primary tenets of the theory.

RESULTS

Specific reason-based recommendations are presented that SLPs can put to practice with their own caseload in direct response to the three tenets of developmental systems theory.

CONCLUSIONS

A developmental systems approach will be useful in expanding SLP knowledge of where to begin and how to best serve children with language, motor, vision, and other concomitant needs. The tenets, including sampling, context dependency, and interdependency, and the application of developmental systems theory can be instrumental in providing a way forward for SLPs struggling with the assessment and intervention of students with complex needs.

"Even though a lot of kids have it, not a lot of people have knowledge of it": A qualitative study exploring the perspectives of parents of children with cerebral/cortical visual impairment

BACKGROUND

Cerebral/Cortical Visual Impairment (CVI) is the leading cause of visual impairment in children and can negatively impact participation in daily activities.

METHODS AND PROCEDURE

This qualitative study used virtual focus groups and an online questionnaire to understand the perspectives of families with children who have CVI. Constant comparison analysis was used to analyze focus group transcripts and extract themes. The PEDI-CAT and an online questionnaire were administered to characterize the study population.

OUTCOMES AND RESULTS

Four themes were identified: (1) Awareness of CVI and its effect on the child and family, (2) Parent experiences, (3) Child factors and functional implications, and (4) Supports that enhance child development/vision.

CONCLUSIONS AND IMPLICATIONS

Findings from this study highlight the substantial impact that lack of CVI awareness had on parent experiences. Lack of awareness led to late diagnosis, missed intervention opportunities, and caregiver burden. Due to insufficient resources, parents had to educate themselves and service providers about CVI and advocate for their child's needs. Healthcare and educational providers who work with pediatric neurodevelopmental populations must be knowledgeable about clinical features of CVI, task and environmental adaptations to support vision and implementation of family-centered care.

Neurovisual profile in children affected by Angelman syndrome

BACKGROUND

Angelman syndrome (AS) is a rare neurogenetic disorder caused by altered expression of the maternal copy of the UBE3A gene. Together with motor, cognitive, and speech impairment, ophthalmological findings including strabismus, and ocular fundus hypopigmentation characterize the clinical phenotype. The aim of this study was to detail the neurovisual profile of children affected by AS and to explore any possible genotype-phenotype correlations.

METHODS

Thirty-seven children (23 females, mean age 102.8 ± 54.4 months, age range 22 to 251 months) with molecular confirmed diagnosis of AS were enrolled in the study. All underwent a comprehensive video-recorded neurovisual evaluation including the assessment of ophthalmological aspects, oculomotor functions, and basic visual abilities.

RESULTS

All children had visual impairments mainly characterized by refractive errors, ocular fundus changes, strabismus, discontinuous/jerky smooth pursuit and altered saccadic movements, and/or reduced visual acuity. Comparing the neurovisual profiles between the deletion and non-deletion genetic subgroups, we found a significant statistical correlation between genotype and ocular fundus hypopigmentation (p = 0.03), discontinuous smooth pursuit (p < 0.05), and contrast sensitivity abnormalities (p < 0.01) being more frequent in the deletion subgroup.

CONCLUSIONS

Subjects affected by AS present a wide spectrum of neurovisual impairments that lead to a clinical profile consistent with cerebral visual impairment (CVI). Moreover, subjects with a chromosome deletion show a more severe visual phenotype with respect to ocular fundus changes, smooth pursuit movements, and contrast sensitivity. Early detection of these impaired visual functions may help promote the introduction of neurovisual habilitative programs which can improve children's visual, neuromotor, and cognitive outcomes.

Including visual orienting functions into cerebral visual impairment screening: Reliability, variability, and ecological validity

BACKGROUND

Cerebral visual impairment (CVI) is a heterogeneous brain-based visual processing disorder in which basic visual orienting functions (VOF) and higher-order perception can be impaired.

AIMS

To evaluate (1) the test-retest reliability and variability of an eye tracking-based VOF paradigm, and related clinical characteristics, and (2) the relations between VOF (variability) and daily visual functioning and visuoperceptual dimensions.

METHODS AND PROCEDURES

Thirty-three children with CVI (Males=14; mean age=9 years 10 months) underwent eye tracking thrice, completed a visuoperceptual battery, and parents completed the Flemish CVI questionnaire. VOF reliability and variability of reaction time (RTF), fixation duration and accuracy were assessed with intraclass correlation coefficient (ICC), Bland-Altman plots, and coefficient of variation. Relations were analysed with linear mixed models.

OUTCOMES AND RESULTS

Highly salient visual stimuli had good RTF reliability (ICCs=0.75) and triggered less variable VOF. Intermediate and low salience stimuli had poor-to-moderate reliability and triggered more variable VOF. Younger performance age related to more VOF variability. Greater visual (dis)interest, clutter and distance viewing impairments, and a weaker visuoperceptual profile related to slower RTF.

CONCLUSIONS AND IMPLICATIONS

Highly salient stimuli reveal a child's 'optimal' visual performance, whereas intermediate and low salience stimuli uncover VOF variability, which is a key CVI hallmark to detect.

Homonymous hemianopia in childhood: a systematic scoping review protocol

Introduction

Cerebral visual impairment (CVI) is the leading cause of visual impairment in childhood in western countries. This encompasses a heterogeneous group of disorders and a spectrum of types of visual impairments. Research is required to explore specific subtypes of CVI and the specific needs of these groups to provide more individualised patient care. One type of CVI is homonymous hemianopia (HH), the absence of vision on one side due to an insult to the postchiasmal visual pathways in one hemisphere of the brain. The scoping review aims to map the nature, features and volume of the existing literature around HH in infancy, childhood and young adolescence.

Methods and analysis

We will perform a scoping review of the literature relating to HH in children (0–18 years old). The review will follow the PRISMA extension for scoping reviews checklist to ensure reporting integrity. We will conduct electronic database searches including CENTRAL, CINAHL, MEDLINE (PubMed) and PsycINFO. We will also carry out a ‘grey literature’ and internet search for studies or materials not formally published. Two researchers will independently review abstracts yielded from the search strategy for study inclusion.

Dissemination

This review will inform health professionals and other stakeholders working within this growing population of children with CVI. Our review will summarise the literature relating to this specific subgroup of CVI, and will identify gaps that require further research and development towards specific care of children with this form of CVI.

Profiles of Children With Cortical Visual Impairment Who Use Augmentative and Alternative Communication: A Retrospective Examination

PURPOSE

Cortical visual impairment (CVI) is the most common cause of visual impairment in children today and can impact the outcomes of children who rely on augmentative and alternative communication (AAC). This study provides baseline data of 13 children with CVI who used AAC during their first year of participation in an integrated CVI program. One purpose was to describe similarities and differences in the student's demographic, functional vision, communication, and educational profiles. A second purpose was to examine differences in students described with different communicator profiles.

METHOD

Archived student records were de-identified and reviewed using a systematic coding scheme. Two researchers independently reviewed and coded all student records. Reliability was established. Measures included CVI Range scores; supports for positioning, mobility, vision, and writing; AAC systems, including modes, access methods, and language representation; communicative competence; self-determination; literacy; and mathematics.

RESULTS

The study yielded a rich description of similarities and differences among students at baseline and led to careful consideration of differences among the participants with emergent communicator and context-dependent communicator profiles.

CONCLUSIONS

Currently, limited evidence exists that informs practice regarding AAC assessment and intervention for children with CVI. This article describes a small sample of children with CVI who use AAC. Results underscore the need for educators and practitioners to ensure that vision functioning in students with CVI is evaluated carefully and regularly when conducting AAC assessment and intervention and formulating communication or education goals.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.21357684.

Validity and reliability of CVI Range assessment for Clinical Research (CVI Range-CR): a longitudinal cohort study

Introduction

Cortical visual impairment (CVI) is the leading cause of paediatric visual impairment in developed countries. Children with CVI exhibit visual behaviours that differ from those with ocular causes of visual impairment. Currently, there is no standard method of assessing these visual characteristics. We have developed a modified version of the CVI Range, a functional vision assessment, suitable for use in clinical research (CVI Range–Clinical Research (CVI Range-CR)). The purpose of this study is to assess the reliability and validity of this instrument in children with CVI.

Methods and analysis

This is a prospective cohort study of 45 children with CVI. A neuro-ophthalmologist will grade visual acuity using the six-level Visual Behaviour Scale (VBS). A neuropsychologist will administer the CVI Range-CR, which will be recorded. The neuropsychologist and two external graders will review and score recorded assessments. These procedures will be performed at baseline and 12 months. We will calculate the intraclass correlation coefficient to assess inter-rater reliability at baseline and follow-up. Additionally, we will correlate CVI Range-CR scores to VBS scores.

Longitudinal neurological analysis of moderate and severe pediatric cerebral visual impairment

Introduction

Cerebral visual impairment (CVI) results from damage to cerebral visual processing structures. It is the most common cause of pediatric visual impairment in developed countries and rising in prevalence in developing nations. There is currently limited understanding on how neurologic, developmental, and ophthalmic factors predict outcome for pediatric CVI.

Method

A retrospective manual chart review of pediatric CVI patients seen at the tertiary pediatric hospital neurology and neuro-ophthalmology service between 2010 and 2019 was conducted. Patients were stratified into severity groups (based on a custom CVI grading score), and followed over time to identify outcome predictors. Collected baseline characteristics included perinatal, genetic, developmental, and neurologic history, along with neuroimaging and fundoscopic findings on examination. Longitudinal data collected included age, seizure control, and type of therapy received. Linear mixed-effect models were used for longitudinal CVI grade outcome analysis.

Results

A total of 249 individuals spanning 779 patient visits were identified. Mean age at diagnosis was 18.8 ± 16.8 months (2–108 months). About 64.3% were born at term age. Perinatal history revealed hypoxic ischemic encephalopathy (HIE) in 16.5%, intraventricular hemorrhage (IVH) in 11.6%, and seizures in 21.7%. At presentation, 60.3% had a diagnosis of cerebral palsy and 84.7% had developmental delay. Among all subjects, 78.6% had epilepsy; 33.8% had an epileptic encephalopathy, with spasms/hypsarrhythmia being most common. Abnormal neuroimaging was present in 93.8%. Genetic anomalies were present in 26.9%. Baseline visual examination revealed no blink-to-light (BTL) in 24.5%; only BTL in 34.5%, fixation/tracking in 26.5%, and optokinetic drum follow in 14.4%. Longitudinal data analysis showed that perinatal history of HIE, a positive epilepsy history, using multiple (≥3) epilepsy medications, cerebral palsy, and abnormal fundoscopic findings were all negatively associated with CVI grade change over time. After controlling for significant confounders, receiving any type of therapy [early childhood intervention (ECI), physical and occupational therapy (PT/OT), refractive error correction or glasses] was significantly associated with longitudinal improvement in CVI grade compared to patients who did not receive any therapy, with glasses yielding the largest benefit.

Conclusion

This study offers extensive insights into neurologic, developmental and ophthalmologic features in patients with moderate to severe CVI. In concordance with previous findings, aspects of perinatal history and epilepsy/seizure control may help inform severity and prognosis in the general neurology or ophthalmology clinic. Conversely, these aspects, as well as genetic and specific epilepsy traits may alert vision health care providers in the clinic to pursue visual evaluation in at-risk individuals. Longitudinal follow-up of CVI patients showed that interventional therapies demonstrated vision function improvement greater than no therapy and maturational development.

Retrospective evaluation of ophthalmological and neurological outcomes for infants born before 24 weeks gestational age in a Swedish cohort

OBJECTIVES

To retrospectively evaluate ophthalmological and neurological outcomes in a Swedish cohort of infants born before 24 weeks gestational age (GA) and explore risk factors for visual impairment.

SETTING

Eye and paediatric clinics in Sweden.

PARTICIPANTS

Infants screened for retinopathy of prematurity (ROP) (n=399), born before 24 weeks GA, 2007-2018. Cases were excluded if ophthalmological follow-up records could not be traced.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcomes were ophthalmological, including visual acuity (VA), refractive error, strabismus, nystagmus and cerebral visual impairment (CVI). Secondary outcomes comprised neonatal and neurological morbidities. Data were retrospectively retrieved from medical records.

RESULTS

The 355 assessed children had a median GA of 23 weeks and 2 days and a median birth weight of 565 g. At the last available ophthalmological examination, the median age was 4.8 years (range 0.5-13.2 years). Nystagmus was recorded in 21.1%, strabismus in 34.8%, and 51.0% wore spectacles. Seventy-three of 333 (21.9%) were visually impaired, defined as being referred to a low vision clinic and/or having a VA less than 20/60 at 3.5 years of age or older. ROP treatment was a significant risk factor for visual impairment (OR 2.244, p=0.003). Visually impaired children, compared with children without visual impairment, more often had neurological deficits such as intellectual disability 63.8% versus 33.3% (p<0.001), epilepsy 21.1% versus 7.5% (p=0.001) and autism spectrum disorders 32.8% versus 20.9% (p=0.043). Nine of the 355 children had been diagnosed with CVI.

CONCLUSIONS

Children born before 24 weeks GA frequently had visual impairment in association with neurological deficits. CVI was rarely diagnosed. A multidisciplinary approach for the evaluation and habilitation of these vulnerable infants is warranted. National follow-up guidelines need to be developed and implemented.

A Review on Recent Advances of Cerebral Palsy

This narrative review summarizes the latest advances in cerebral palsy and identifies where more research is required. Several studies on cerebral palsy were analyzed to generate a general idea of the prevalence of, risk factors associated with, and classification of cerebral palsy (CP). Different classification systems used for the classification of CP on a functional basis were also analyzed. Diagnosis systems used along with the prevention techniques were discussed. State-of-the-art treatment strategies for CP were also analyzed. Statistical distribution was performed based on the selected studies. Prevalence was found to be 2-3/1000 lives; the factors that can be correlated are gestational age and birth weight. The risk factors identified were preconception, prenatal, perinatal, and postnatal categories. According to the evidence, CP is classified into spastic (80%), dyskinetic (15%), and ataxic (5%) forms. Diagnosis approaches were based on clinical investigation and neurological examinations that include magnetic resonance imaging (MRI), biomarkers, and cranial ultrasound. The treatment procedures found were medical and surgical interventions, physiotherapy, occupational therapy, umbilical milking, nanomedicine, and stem cell therapy. Technological advancements in CP were also discussed. CP is the most common neuromotor disability with a prevalence of 2-3/1000 lives. The highest contributing risk factor is prematurity and being underweight. Several preventions and diagnostic techniques like MRI and ultrasound were being used. Treatment like cord blood treatment nanomedicine and stem cell therapy needs to be investigated further in the future to apply in clinical practice. Future studies are indicated in the context of technological advancements among cerebral palsy children.

Exploring the Need for Education on Cortical Visual Impairment Among Occupational Therapy Professionals and Teachers of Students With Visual Impairments

Introduction: Cortical or cerebral visual impairment (CVI) is the leading cause of bilateral visual impairment in developed countries. The goals of this study were to explore the CVI education and training received by occupational therapy practitioners and teachers of students with visual impairments and to quantify the confidence of these professionals to evaluate and work with children who are diagnosed with CVI. Methods: An Internet-based survey was conducted with a volunteer sample that included occupational therapists, certified occupational therapy assistants, and certified teachers of students with visual impairments who practice in 50 U.S. states; Washington, D.C.; and Canada. The survey was posted on professional organizations and social media websites, as well as emailed to colleagues at organizations such as the Association for the Education and Rehabilitation of the Blind and Visually Impaired, schools for students who are blind, and local universities. Data collection occurred between June 2019 and November 2019. Results: Surveys were completed by 205 respondents from 43 U.S. states; Washington, D.C.; and Canada. Occupational therapy practitioners consistently reported lower rates of formal education in CVI, with only 25% of occupational therapists and 47% of certified occupational therapy assistants receiving education on CVI in their academic programs. Less than 23% of occupational therapists received training on CVI assessments, whereas 75% of teachers of students with visual impairments had training in CVI assessments. Additionally, respondents indicated reduced satisfaction with their knowledge and skills for treating or teaching children with CVI. Discussion: The results indicate a gap in formal CVI education for occupational therapy practitioners and, to a lesser extent, teachers of students with visual impairments. Due to the increasingly high prevalence of CVI, the gap in formal education on CVI is significant. Implications for Practitioners: Results indicate the need to increase formal and continuing education for occupational therapy practitioners and teachers of students with visual impairments.

Visual Function and Neuropsychological Profile in Children with Cerebral Visual Impairment

Cerebral Visual Impairment (CVI) has become the leading cause of children’s visual impairment in developed countries. Since CVI may negatively affect neuropsychomotor development, an early diagnosis and characterization become fundamental to define effective habilitation approaches. To date, there is a lack of standardized diagnostic methods to assess CVI in children, and the role of visual functions in children’s neuropsychological profiles has been poorly investigated. In the present paper, we aim to describe the clinical and neuropsychological profiles and to investigate the possible effects of visual functions on neuropsychological performance of a cohort of children diagnosed with CVI. Fifty-one children with CVI were included in our retrospective analysis (inclusion criteria: verbal IQ > 70 in Wechsler scales; absence of significant ocular involvement). For each participant, we collected data on neuropsychological assessment (i.e., cognitive, cognitive visual, and learning abilities), basic visual functions (e.g., Best Corrected Visual Acuity—BCVA, contrast sensitivity, and ocular motor abilities) and global development features (e.g., neurological signs and motor development delay) based on standardized tests, according to patients’ ages. The results showed that oculomotor dysfunction involving saccades and smooth pursuit may be a core symptom of CVI and might have a significant impact on cognitive visual and other neuropsychological abilities. Furthermore, visual acuity and contrast sensitivity may influence cognitive, cognitive visual, and academic performances. Our findings suggest the importance of a comprehensive assessment of both visual and neuropsychological functions in children when CVI is suspected, which is needed to provide a more comprehensive functional profile and define the best habilitation strategy to sustain functional vision.

Working with children with cortical visual impairment who use augmentative and alternative communication: implications for improving current practice

The aim of this study was to describe how professionals from multiple disciplines (e.g., speech-language pathologists, teachers, occupational therapists) in the United States reported challenges they face in delivering services to children with cortical visual impairment (CVI) who use augmentative and alternative communication (AAC). Three surveys were utilized to identify barriers to and priorities for improving educational and clinical services and in-service and preservice education from the perspectives of professionals in school, community, and university settings. Results suggest that current service delivery models may not be meeting the needs of either children with CVI who use AAC or the professionals whose job it is to provide them with services. Professionals in community-based settings appeared to encounter more barriers. Findings help to support a discussion about approaching AAC interventions for children with CVI who use AAC by adopting interprofessional collaborative practice (IPCP) and interprofessional education (IPE) models, which reflect long-standing best practice guidelines for AAC service delivery and are encouraged by multiple professional organizations.

A Pilot Nurse-Led Tele-Counseling Intervention to Parents of Children With Cerebral Visual Impairment on Adherence to Eye Activities During COVID-19 Pandemic: A Pre-experimental Study

Aim

To assess the impact of a culturally appropriate and theoretically driven nurse-led tele-counseling intervention to parents of children with cerebral visual impairment (CVI) on the adherence to visual therapy advised by the ophthalmologists.

Design

A pre-experimental design was used.

Methods

Parents of children with CVI aged 2–9 years were enroled telephonically during the coronavirus disease 2019 (COVID-19) pandemic through the Pediatric Ophthalmology Clinic of a tertiary eye care center. Pre-assessment of participants was done telephonically as per the interview schedule. As per the protocol, the trained nurse-delivered tele-counseling intervention two times weekly for the first 2 weeks and weekly for the next 2 weeks via audio and video two-way tele-interaction with parents. A CVI information booklet was shared with parents via WhatsApp interface and individualized visual therapy was reinforced in accordance with the advice of the treating ophthalmologist. It was based on a thorough review of clinical records of the child, such as a detailed CVI questionnaire, history, and findings of clinical examination and neuro-visual behavior of a child. In addition, parents were encouraged to maintain a diary of the daily sessions of visual therapy and share recorded videos of their training exercises which were then evaluated and discussed with the ophthalmologist for any deviation. Outcome measures included adherence to eye activities for 7–8 sessions per day. Data were analyzed by using SPSS statistics for windows, version 20.

Results

Overall, improvement of adherence to visual therapy was observed among children with CVI (p &lt; 0.0001). Nearly half (47.6%) of participants adhered to 3–4 sessions/day and only 28.6% were adherent to the recommended 7–8 sessions/day.

Conclusion

The pilot study demonstrated the potential of the nurse-led tele-counseling intervention to supplement the ongoing health treatment of patients in improving the adherence to eye activities among parents of children with CVI.

Exploratory Investigation of Brain MRI Lesions According to Whole Sample and Visual Function Subtyping in Children With Cerebral Visual Impairment

Background: There is limited research on brain lesions in children with cerebral visual impairment (CVI) of heterogeneous etiologies and according to associated subtyping and vision dysfunctions. This study was part of a larger project establishing data-driven subtypes of childhood CVI according to visual dysfunctions. Currently there is no consensus in relation to assessment, diagnosis and classification of CVI and more information about brain lesions may be of potential diagnostic value.

Aim: This study aimed to investigate overall patterns of brain lesions and associations with level of visual dysfunction and to compare the patterns between the classification subgroups in children with CVI.

Methods: School-aged children with CVI received ophthalmological and neuro-psychological/developmental assessments to establish CVI-related subtyping. Other pediatric information was collected from medical records. MRI scans were coded according to a semi-quantitative template including brain regions (right hemisphere, left hemisphere, visual pathways) and summed for total scores. Non-parametric analyses were conducted.

Results: 28 children had clinical brain MRI scans available [44% of total sample, Group A (lower severity of visual dysfunctions) n = 16, Group B (higher severity) n = 12]. Total brain scores ranged between 0 and 18 (Group A mdn = 7, IQR = 0.8–10.0, Group B mdn = 10, IQR = 6.5–11.8) and were widespread across regions. 71 per cent had post-geniculate visual pathway damage. The median total brain and hemisphere scores of Group B were higher than subgroup A but differences did not reach statistical significance. No statistically significant associations were found between brain scores and vision variables (acuity, contrast sensitivity).

Conclusion: This study found a spread of lesions across all regions on the brain scans in children with congenital CVI. The majority had damage in the postgeniculate visual pathways and visual cortex region suggesting this is an area of interest and potentially informative for diagnosis. However the subtyping classification did not show differences in number or region of lesions though the trend was higher toward Group B. This study confirms the complex diffuse and variable nature of brain lesions in children with congenital CVI, many of whom have other neurological impairments.

Validity and reliability of eye tracking for visual acuity assessment in children with cortical visual impairment

BACKGROUND

Cortical visual impairment (CVI) is the leading cause of pediatric visual impairment in developed countries, but there is currently no evidence-based treatment. A method of visual assessment that captures multiple domains of visual functioning may facilitate evaluation of proposed therapies. We have developed an eye-tracking protocol that evaluates afferent, efferent, and higher-order visual parameters in children with CVI. We report its validity and reliability in assessing visual acuity.

METHODS

We recruited 16 children with CVI between the ages of 12 months and 12 years. Visual acuity was assessed clinically using a previously published six-level scale of visual behavior. Grating acuity was assessed by eye tracking using forced-choice preferential looking, which was performed at baseline and 1 month for reliability testing. Validity was assessed by correlating clinical acuity with grating acuity by eye tracking.

RESULTS

Clinical visual acuity ranged from 3 to 6 on the six-level scale, and grating acuity ranged from 0.25 to 20 cycles per degree (logMAR 0.18-2.08). There was strong correlation between grating acuity by eye tracking and clinical acuity assessment (ρ = -0.82; P = 0.0002). Test-retest reliability was excellent, with an intraclass correlation coefficient of 0.96 (95% CI, 0.88-0.99).

CONCLUSIONS

Eye tracking demonstrates excellent reliability for visual acuity assessment and high correlation with clinical assessment of visual acuity in pediatric CVI. Future research is necessary to determine whether eye tracking can assess other visual and oculomotor parameters in children with CVI, a prerequisite for incorporating this technique into future clinical trials and patient care.

Visual search performance in cerebral visual impairment is associated with altered alpha band oscillations

Individuals with cerebral visual impairment (CVI) often present with deficits related to visuospatial processing. However, the neurophysiological basis underlying these higher order perceptual dysfunctions have not been clearly identified. We assessed visual search performance using a novel virtual reality based task paired with eye tracking to simulate the exploration of a naturalistic scene (a virtual toy box). This was combined with electroencephalography (EEG) recordings and an analysis pipeline focusing on time frequency decomposition of alpha oscillatory activity. We found that individuals with CVI showed an overall impairment in visual search performance (as indexed by decreased success rate, as well as increased reaction time, visual search area, and gaze error) compared to controls with neurotypical development. Analysis of captured EEG activity following stimulus onset revealed that in the CVI group, there was a distinct lack of strong and well defined posterior alpha desynchronization; an important signal involved in the coordination of neural activity related to visual processing. Finally, an exploratory analysis revealed that in CVI, the magnitude of alpha desynchronization was associated with impaired visual search performance as well as decreased volume of specific thalamic nuclei implicated in visual processing. These results suggest that impairments in visuospatial processing related to visual search in CVI are associated with alterations in alpha band oscillations as well as early neurological injury at the level of visual thalamic nuclei.

Cortical Visual Impairments and Learning Disabilities

Medical advances in neonatology have improved the survival rate of premature infants, as well as children who are born under difficult neurological conditions. As a result, the prevalence of cerebral dysfunctions, whether minimal or more severe, is increasing in all industrialized countries and in some developing nations. Whereas in the past, ophthalmological diseases were considered principally responsible for severe visual impairment, today, all recent epidemiological studies show that the primary cause of blindness and severe visual impairment in children in industrialized countries is now neurological, with lesions acquired around the time of birth currently comprising the commonest contributor. The resulting cortical or cerebral visual impairments (CVIs) have long been ignored, or have been confused either with other ophthalmological disorders causing low vision, or with a range of learning disabilities. We present here the deleterious consequences that CVI can have upon learning and social interaction, and how these can be given behavioral labels without the underlying visual causes being considered. We discuss the need to train and inform clinicians in the identification and diagnosis of CVI, and how to distinguish the diagnosis of CVI from amongst other visual disorders, including the specific learning disorders. This is important because the range of approaches needed to enhance the development of children with CVI is specific to each child's unique visual needs, making incorrect labeling or diagnosis potentially detrimental to affected children because these needs are not met.

Transient cortical blindness secondary to hepatic encephalopathy in a pediatric patient: A case report and literature review

Cortical blindness, also known as cerebral visual impairment, may occur in pediatric patients. Hepatic encephalopathy is a rare cause of cortical blindness in children. This report describes a girl with underlying type 1 autoimmune hepatitis, who complained of sudden-onset, painless visual loss in both eyes, which was associated with generalized headache and altered mental status. She was treated with intravenous antibiotics and syrup lactulose. The patient regained full visual recovery after 1 week. Prompt diagnosis and treatment are mandatory in such uncommon instances.

Cerebral Visual Impairment in CDKL5 Deficiency Disorder Correlates With Developmental Achievement

Cyclin-dependent kinase-like 5 (CDKL5) deficiency disorder is a rare neurodevelopmental disorder characterized by infantile-onset refractory epilepsy, profound developmental delays, and cerebral visual impairment. Although there is evidence that the presence of cerebral visual impairment in CDKL5 deficiency disorder is common, the potential impact of cerebral visual impairment severity on developmental attainment has not been explored directly. Focusing on a cohort of 46 children with CDKL5 deficiency disorder, examination features indicative of cerebral visual impairment were quantified and compared to developmental achievement. The derived cerebral visual impairment severity score was inversely correlated with developmental attainment, bolstering the supposition that cerebral visual impairment severity may provide a useful early biomarker of disease severity and prognosis. This study demonstrates the utility of a cerebral visual impairment score to better capture the range of cerebral visual impairment severity in the CDKL5 deficiency disorder population and further elucidates the interaction between cerebral visual impairment and developmental outcomes.