Cortical visual impairment in children - A new challenge for the future?

Correlation of optic nerve on magnetic resonance imaging with visual acuity in children with cerebral visual impairment

AIM

The aim of the study was to correlate the optic nerve dimensions at various locations on magnetic resonance imaging (MRI) with the visual acuity of children with cerebral visual impairment (CVI).

MATERIALS AND METHODS

A 1-year cross-sectional study was conducted in a tertiary care hospital involving 60 children aged 1 to 12 years diagnosed with CVI but without ocular pathologies. Visual acuity was evaluated using teller acuity cards (TACs). MRI of the brain and orbit was performed using three-dimensional high-resolution, volumetric heavily T2-weighted sequences to screen for brain pathologies and measure optic nerve dimensions at two locations. The correlation between visual acuity and optic nerve dimensions was analyzed. The Chi-square test was employed to assess significance using SPSS software.

RESULTS

In our study, 64% (n = 38) of the participants were children under 3 years of age. The severity and characteristics of CVI influenced visual functioning at different ages. As children with CVI grew older and moved from Phase I to Phase III, the proportion with very low visual acuity significantly decreased from 85.2% in Phase I to 22.2% in Phase III and from 63.2% in the <3-year age group to 18.2% in more than 5-year age group. No direct correlation was found between optic nerve dimensions and visual acuity but optic disc changes such as optic disc pallor significantly correlated with low visual acuity.

CONCLUSION

Our findings suggest that there may not be a direct correlation between optic nerve dimensions and visual acuity in children with CVI. However, optic disc changes do correlate with visual acuity, but optic disc changes alone are not a criterion for assessing visual function. Additionally, our study highlights the significance of a combined assessment by a neuro- ophthalmologist and neuro-pedaitrician in children with CVI.

Cerebral versus cortical visual impairment: eliminating the conflict and renewing the terminology

The inconsistency in terminology for Cortical Visual Impairment or Cerebral Visual Impairment presents challenges: (1) different levels of changes in visual pathway and other cerebral areas do not allow discrimination; (2) different visual and oculomotor aspects are not adequately considered. We open a debate to consider a more appropriate diagnosis.

Validation of the Austin Assessment: A screening tool for cerebral visual impairment related visual issues

Cerebral visual impairment is the most common cause of vision impairment affecting children in the economically developed world with a prevalence rate of approximately 3.4%. Currently there are limited options for screening for cerebral visual impairment, resulting in many children going undiagnosed, especially those that have normal visual acuity. The aim of this research was to validate an iPad App called the Austin Assessment, which was developed as a potential screening tool for cerebral visual impairment related visual issues. The research involved three separate phases: (1) creating a database of normative ranges for children aged 5-18 across the different variables of the Austin Assessment, (2) using the Austin Assessment to screen children aged 5-13 to assess the effectiveness of the Austin Assessment as a screening tool for CVI related visual issues, and (3) conducting specific validation research assessing children using the Austin Assessment and an already validated visual search tool. Each phase used different quantitative research methodologies to help show the effectiveness of the Austin Assessment as a screening tool for cerebral visual impairment related visual issues. From phase one of the research, thresholds were established for three variables of the Austin Assessment for the age groupings of 5-8, 9-12 and 13-18. If a child meets one of these thresholds this indicates further assessment is required to determine if they do in fact have cerebral visual impairment related visual issues. Phase two identified 17 children out of 270 who had clinical findings indicating visual issues; potentially indicative of CVI; investigation into the nature of these visual issues is ongoing. Phase three found that the Austin Assessment has moderate diagnostic value for each age group, with good sensitivity and specificity, making it effective at distinguishing those children who have visual issues from those who have typical vision. Further investigation is needed to confirm this initial validation.

Cerebral visual impairment and effect of phase-wise stimulation strategies-An interim analysis

Context

Cerebral visual impairment (CVI) is an overarching term, defined as a brain-based visual impairment with onset in childhood, unexplained by an ocular disorder and associated with unique visual and behavioral characteristics. Good vision and awareness of visual function in a child are highly essential as neuroplasticity is maximum in the first three years of life and response to intervention is utmost in this period. Awareness is lacking regarding CVI, and the diagnosis is largely missed. This can be easily addressed if a structured approach is employed.

Purpose

This study aims to evaluate the etiology and radiological correlation with the severity of CVI and outcome after structured intervention in children with CVI.

Settings and Design

Prospective-interventional study.

Methods and Material

Children attending the Child Development Centre (CDC) of a tertiary care hospital in North Karnataka and diagnosed with CVI in the age group of six months to 12 years and meeting the sampling criteria were screened and enrolled consecutively after obtaining parental consent/assent. Statistical analysis used is nonparametric test with SPSS software.

Results

Age showed a significant association with the phase of CVI. Perinatal insult was associated significantly with the severity of CVI. Magnetic resonance imaging (MRI) findings did not hamper the recovery of CVI.

Conclusions

Enrolment in early intervention programs tailored according to child's specific needs should be encouraged, with stress on ophthalmic screening of preterm and high-risk babies with perinatal hypoxia and history of convulsions, as early as six months.

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.

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.

Considerations for the identification of autism spectrum disorder in children with vision or hearing impairment: A critical review of the literature and recommendations for practice

OBJECTIVE

There is higher risk for autism spectrum disorder (ASD) across many pediatric neurological conditions characterized by vision impairment or hearing loss. Early and accurate identification of ASD is imperative in promoting access to appropriate and early evidenced-based intervention; however, differential diagnosis can be particularly challenging in children with sensory impairment given the heterogeneity of ASD combined with the impact of vision impairment or hearing loss/deafness on development and behavior. A neuropsychologist's unique expertise and appreciation of the interplay between sensory and behavioral manifestations can be valuable for making an early and accurate ASD diagnosis in children who are blind/visually impaired or deaf/hard-of-hearing. This article highlights clinical considerations when identifying ASD within the context of vision impairment or hearing loss/deafness.

METHOD

We discuss clinical considerations for the early identification of ASD in children who are blind/visually impaired and deaf/hard-of-hearing. Information presented in the article is based on a critical review of the literature and the expertise of the author group.

CONCLUSION

Ongoing development of clinical expertise and evidence-based assessment methods are important when informing the early differential diagnosis of ASD in individuals with sensory impairment. Accurate identification is also vital for the development of targeted interventions across the lifespan.

Abnormal Vestibular-Ocular Reflexes in Children With Cortical Visual Impairment

BACKGROUND

To determine whether the vestibular-ocular reflexes (VORs) can be affected by central nervous system injury in children with cortical visual impairment (CVI).

METHODS

Retrospective case series. Twenty consecutive children with CVI who presented to a pediatric ophthalmology practice over an 18-month period were included in the study. Horizontal and vertical VORs were assessed by a pediatric neuro-ophthalmologist using the standard doll's head maneuver. MRI studies were independently reviewed by a pediatric neuroradiologist in a masked fashion. The main outcome measures were the integrity of the VORs and the presence of brainstem abnormalities on MRI.

RESULTS

VORs were found to be absent or severely impaired in 13/20 (65%) children with CVI. More surprisingly, the doll's head maneuver failed to substantially overcome the deviated eye position in 8/13 (62%) children with conjugate gaze deviations. Reduced brainstem size and signal abnormalities were found in 4/7 children with normal VORs and in 9/13 children with abnormal VORs (P = 0.6), showing noncorrelation with the integrity of the VOR.

CONCLUSION

VORs are commonly impaired in children with CVI. This ocular motor deficit reflects the diffuse cortical and subcortical injury that often accompanies perinatal injury to the developing brain. Consequently, these children may lack important visual compensatory mechanisms to stabilize gaze during head movements. This knowledge can help in planning visual rehabilitation.

Creating a Path for Systematic Investigation of Children With Cortical Visual Impairment Who Use Augmentative and Alternative Communication

Purpose There is limited information about how to support children with cortical visual impairment (CVI) who require augmentative and alternative communication (AAC). An initial review designed to explore the available evidence was used to outline critical needs in moving research and intervention forward for children who use AAC and have CVI. Method Previous systematic reviews, six databases, and theses and dissertations were systematically searched, along with reviews of the resulting works cited. An initial yield of 575 articles was narrowed to 10, which discussed AAC interventions that included children with CVI. Results Three interventions were technology based, and seven were instructional based. The use of textured microswitches was the most frequent form of technology intervention, with the frequency of switch activations being the most frequently coded outcome. Overall, the studies represent explorations in the area rather than systematic lines of inquiry. Conclusions While evidence shows at least some children with CVI have been included in AAC research to date, the inclusion is more incidental than deliberate. Issues such as clear descriptions of the vision capabilities and needs of participants may have impacted study results.

Children With Cortical Visual Impairment and Complex Communication Needs: Identifying Gaps Between Needs and Current Practice

Purpose This scoping study sought to establish a baseline for how well the needs of children with cortical visual impairment (CVI) who use augmentative and alternative communication (AAC) are currently aligned with the services available to them. CVI is the most common cause of visual impairment in children today, and AAC methods rely heavily on vision. Yet, the prevalence of CVI in children who use AAC methods is not yet known, and there is virtually no research concerning use of AAC with children with CVI. Our overarching goals were to identify barriers and suggest priorities for improving outcomes for these children. Method Surveys were distributed anonymously online to professionals from multiple disciplines in different school-based settings and to parents of children with CVI who use AAC. Results School-based professionals identified many barriers, including a lack of knowledge and skills about CVI and about AAC, limited access to training and experts, and concerns about services being delivered in isolated silos with limited time allotted for interprofessional collaboration and planning. Parent reported that their children (M _age = 11 years) continued to rely predominantly on body-based forms of communication and lacked access to symbolic language, which, in AAC, is primarily visually based. Conclusions The barriers to services identified by school-based professionals indicate a need to develop and disseminate reliable information about CVI and AAC, both at a preservice and in-service level and, while doing so, to respect the diversity of stakeholders who need this information, including parents. Future research on what types of AAC approaches support the development of language and communication skills for children with CVI is essential.

Visual Status in a Portuguese Population with Intellectual Disability

BACKGROUND

Neurosensory deprivation associated with vision is a well-known fact in people with intellectual disability (ID). This work aims to report the visual status of a population with ID in Portugal.

METHODS

A vision screening protocol was conducted during two Special Olympics events. The vision protocol included personal medical history, ocular health evaluation, and clinical measures, such as visual acuity (VA), binocular vision, colour vision, refractive error, and intraocular pressure. This protocol was administered to 134 subjects.

RESULTS

Half of the subjects reported that they had never attended or they did not remember having attended a previous eye exam. Additionally, 10% of them had not attended an eye exam in the immediate past three years. Half the subjects failed the VA test and 13% presented moderate Visual Impairment (VI) (VA worse than 0.5 logMAR in the best eye). Manifest ocular deviation was found in 25% of the subjects and the most common ocular health dysfunction conditions were conjunctiva hyperaemia, meibomian gland dysfunction, and lens anomalies. Refractive error correction allowed a reduction in the level of moderate VI to 3.7%.

CONCLUSIONS

The population analysed showed a poor eye care attendance rate and vision-related conditions are in agreement with previous reports. The development of national strategies to promote the awareness for routine eye care in people with ID and improving accessibility to eye care services may mitigate many of the most prevalent conditions encountered.

Sensory Integration and Functional Reaching in Children With Rett Syndrome/Rett-Related Disorders

Background

The loss of functional hand skills is a primary characteristic of Rett syndrome. Stereotypies, dyspraxia, and other sensory processing issues severely limit the individual's ability to reach toward and sustain grasp on objects. This loss of functional reach and grasp severely limits their ability to participate in self-help, play, and school-related activities. We proposed that Ayres Sensory Integration (ASI) treatment would improve sensory processing and motor planning, which would lay the sensory-motor groundwork for improving grasp of objects, an important first step in developing functional hand use.

Objective

We examined effects of ASI treatment on rate of reaching and grasping for children with Rett syndrome/Rett-related disorders.

Methods

We used an interrupted time series design to measure changes in outcome variables occurring after intervention initiation and cessation. We analyzed daily video observations during baseline, intervention, and post-intervention periods, over a span of 7 months.

Results

During baseline, rate of grasping declined moderately. There was a 15% increase in grasping from the end of baseline to end of the post-intervention period. There was no significant change in rate of reaching.

Conclusions

This study provides preliminary data showing very small improvements in hand grasp of children with Rett syndrome following ASI treatment; larger studies in diverse settings are needed to establish the effectiveness of this approach. This study shows that an interrupted time series research design provides a valid template for evaluating interventions for children with rare disorders.

Cortical Visual Impairment in Congenital Cytomegalovirus Infection

PURPOSE

To describe the presentation, evolution, and long-term outcome of cortical visual impairment (CVI) in patients with symptomatic congenital cytomegalovirus (CMV) infection, and to identify risk factors for the development of CVI in patients with symptomatic congenital CMV.

METHODS

Retrospective subanalysis of a long-term prospective cohort study with data gathered from 1982 to 2013.

RESULTS

Eleven of 77 (14.3%) patients with symptomatic CMV, 0 of 109 with asymptomatic CMV, and 51 control patients had CVI. Overall, patients with symptomatic CMV had worse vision than patients with asymptomatic CMV, who in turn had worse vision than control patients. Microcephaly, intracranial calcification, dilatation of ventricles, encephalomalacia, seizure at birth, optic atrophy, chorioretinitis/retinal scars, strabismus, and neonatal onset of sensorineural hearing loss were risk factors associated with CVI.

CONCLUSIONS

CVI may result from symptomatic congenital CMV infection. The relationship of CVI and its risk factors in patients with CMV suggests the potential to predict the development of CVI through predictive modeling in future research. Early screening of CVI in children born with symptomatic congenital CMV can facilitate educational, social, and developmental interventions. [J Pediatr Ophthalmol Strabismus. 2019;56(3):194-202.].

A pilot study regarding basic knowledge of "cortical visual impairment in children" among ophthalmologists

Purpose:

A pilot study was done to evaluate knowledge regarding “cortical visual impairment (CVI) in children” among ophthalmologists.

Methods:

This study was conducted during the annual conference of a zonal ophthalmological society. All ophthalmologists who attended the conference were requested to participate in this study. Those who agreed were given a validated questionnaire to assess knowledge regarding CVI. Cronbach's alpha of the questionnaire was 0.6. Participants were asked to respond to multiple choice questions by choosing the single best option. The responses obtained were then evaluated.

Results:

The total number of registered delegates in the conference was 448. A total of 103 ophthalmologists showed interest to participate in the study with a response rate of 22.9%. Only 89/103 interested delegates were included in the study as remaining were unaware of CVI. No participant gave correct answers to all questions. Although more than 80% of them knew the most common association (87%) and site of pathology (84%), only 52% were sure about clinical features and even lesser respondents (39%) knew that magnetic resonance imaging is the correct investigation of choice. The majority responded correctly that these children need eye examination (89%) and can be managed by rehabilitation through multidisciplinary approach (82%), but only 58% could recognize differential diagnoses and had a correct idea regarding the prognosis of CVI. There was no correlation between the number of patients diagnosed per month by the respondent with knowledge of the disease.

Conclusion:

In this pilot study, ophthalmologists were found to have limited knowledge regarding clinical features, investigation, differential diagnosis, and visual prognosis of CVI in children. There is a need to improve awareness regarding CVI among ophthalmologists.

Neuro-ophthalmic manifestations of prematurity

Increasing rates of preterm births coupled with better survival of these infants have resulted in higher prevalence of systemic and ocular complications associated with prematurity. In addition to retinopathy of prematurity, infants who are born preterm may suffer from severe visual impairment as a result of hypoxic ischemic encephalopathy, hypoglycemia, and other metabolic imbalances. The effect of these processes on the anterior visual pathway may result in optic atrophy, optic nerve hypoplasia or optic disc cupping and affection of the posterior visual pathway leads to cortical visual impairment (CVI). Other ocular associations include strabismus, nystagmus, and ocular motor abnormalities such as tonic down gaze and defective saccades and pursuits. Cortical and subcortical involvement also manifests as defects in functional vision and these have not yet been completely understood. Children with CVI may have visual field defects, photophobia, defective visual processing, and deficient color vision. Since most of these children also suffer from additional systemic disabilities, evaluation, and management remains a challenge. However, early diagnosis and initiation of rehabilitation therapy can prove to be of significant benefit in these children.

Orienting responses to various visual stimuli in children with visual processing impairments or infantile nystagmus syndrome

Quantification of orienting responses can be used to differentiate between children with cerebral visual impairment and infantile nystagmus syndrome. To further improve the sensitivity of this method, we compared orienting responses to a Cartoon stimulus, which contains all sorts of visual information, to stimuli that contain only Contrast, Form coherence, Motion coherence, Color and Motion detection. The stimuli were shown on an eye tracker monitor using a preferential looking paradigm. We found that both groups of children showed general slowing in orienting responses compared to controls. The children with cerebral visual impairment had significantly prolonged responses to Cartoon compared to the children with nystagmus, whereas the children with nystagmus had prolonged responses to Motion detection and larger fixation areas. Previously reported differences in orienting responses to Cartoon were replicated. Application of specific visual information did not alter the sensitivity of the method to distinguish between children with visual processing deficits.