Diagnosis Of Cerebral Visual Impairment Research Articles

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

To classify CVI subtypes and compare the added value of an extensive test battery over a limited test battery in subtype classification of cerebral visual impairment (CVI) in children. Seventy-five children with a clinical diagnosis of CVI (median [IQR] age: 9 [7-12] years) were identified from the medical records. The extensive test battery included visual acuity, contrast sensitivity, ocular alignment, eye movement analysis, visual field analysis, optic nerve head evaluation, and evaluation of visual perception. The limited test battery included visual acuity, contrast sensitivity, ocular alignment, and evaluation of visual perception. Principal component analysis (PCA) followed by cluster analysis was done, for both test batteries separately, to determine the optimum subtype classification for CVI. Fifty-one participants with an extensive test battery with mild to moderate visual impairment were included in the main analysis. This resulted in four CVI subtypes for the extensive test battery (subtle characteristics, higher-level visual function deficits, lower-level visual function deficits, and higher- and lower- level visual function deficits) and three CVI subtypes for the limited test battery (subtle characteristics, higher-level visual function deficits, and higher- and lower- level visual function deficits). There were significant differences between the subtypes for 9 out of 10 measures of the extensive and all 4 measures of the limited test battery (p < 0.05). The subtle characteristics subtype (extensive n = 19, limited n = 15) showed near normal lower and higher-level visual functions in both test batteries. The higher-level visual function deficits subtype (extensive n = 18, limited n = 24) showed near normal visual acuity combined with significant visual perceptual deficits in both test batteries; accompanied by visual pathways defects and abnormal eye movement behavior in the extensive test battery. The higher- and lower- level visual function deficits subtype (extensive n = 4, limited n = 12) showed both higher and lower-level visual function deficits in both test batteries, but application of the extensive test battery revealed additional visual pathways defects and abnormal eye movement behavior. The lower-level visual function deficits CVI subtype (extensive n = 10) was a new subtype identified by the extensive test battery. This subtype showed lower-level visual function deficits together with abnormal eye movement measures. This data-driven study has provided meaningful CVI subtype classifications based on the outcomes of various key functional and structural measures in CVI diagnosis. Comparison of the extensive test battery to the limited test battery revealed the added value of an extensive test battery in classifying CVI. The outcomes of this study, therefore, have provided a new direction in the area of CVI classification.

Visual Behaviours (ViBes) in Cerebral Visual Impairment: Validating a Descriptive Tool to Support Diagnosis and Monitoring.

Cerebral visual impairment (CVI) is the most common cause of visual impairment in children in the UK. Diagnosis is based on identification of visual behaviours (ViBes) relating to visual dysfunction. Examination techniques and inventories have been developed to elicit these in children with a developmental age of two years or more. The absence of a structured approach to recording visual behaviours in children with complex needs is a barrier to diagnosis. The aim of the study was to develop a matrix of visual behaviours seen in pre-verbal and pre-motor children with visual impairment and establish its content validity and inter-rater reliability. ViBe content validation:: Visual behaviour descriptors relating to visual function were collated and categorised by expert consensus of vision professionals into a matrix composed of three functions (attention, field/fixation, motor response) and five levels (0 = no awareness; 1 = visual awareness; 2 = visual attention; 3 = visual detection; 4 = visual understanding).ViBe inter-rater reliability:: The participants (two orthoptists, an optometrist, an ophthalmologist and two qualified teachers of the visually impaired) used the ViBe matrix to independently score each of 17 short video clips of children demonstrating visual behaviours seen in CVI. The ViBe matrix will be presented. Cohen's kappa for the matrix was 0.67, demonstrating moderate-to-strong inter-rater reliability. The development of standardised descriptors can support clinicians and teachers in identifying areas of concern for children with complex needs. In addition, the ViBe matrix could be utilised in research, clinical and diagnostic reports to clearly communicate the areas of visual dysfunction and track progress resulting from interventions. The absence of a structured approach to recording visual behaviours in children with complex needs is a barrier to diagnosis.The ViBe matrix offers descriptors relating to visual behaviours and has demonstrated acceptable inter-rater reliability.The tool may support the identification and diagnosis of cerebral visual impairment in a population of children who cannot access standard testing.

Ocular morbidity and co-morbidities in children attending a nodal district early intervention center in Uttar Pradesh.

To obtain epidemiological data on children with ocular morbidity attending a nodal district early intervention center (DEIC). : After parental consent, we recruited children with ocular morbidity. After detailed history and clinical evaluation, along with pediatric consultation and relevant neuro-radiological and ancillary investigation, information was entered in a pretested proforma: especially looking for perinatal morbidity, including developmental delay (DD). Visual acuity (VA) was assessed by age-appropriate means by an ophthalmic assistant trained to work with children with special needs. We diligently looked for strabismus and performed dilated ophthalmoscopy. Using JASP, we summarized data as means and proportions and reported 95% CIs. We explored the association of disability percentage with possible predictor variables using regression. We enrolled 320 children, with a mean age of 34.43 ± 31.35 months; two-thirds were male; one-third belonged to lower socioeconomic status (36%), with most parents being illiterate. The mean presenting VA was 1.8 logMAR for both eyes, range: 0 to 3. Sixty-one percent were hyperopic and 27% were myopic. High refractive error, (>±6D) occurred in nine; anisometropia in one; strabismus in 149, mostly esotropia; congenital cataract in 25, whereas 63 had abnormal fundus. Seventy-six received a diagnosis of cerebral visual impairment (CVI). On multivariate linear regression (MLR), younger age, presence of DD, and CVI significantly predicted a higher disability percentage. Logistic regression revealed that statutory disability is likely associated with DD (odds ratio [OR]:13.43); whereas older age was protective (OR: 0.977). Our study suggests that in DEIC children with ocular morbidity, younger children, and the presence of DD significantly predict both greater disability and the likelihood of statutory levels.

Cerebral visual impairment and educational support in the United Kingdom: Understanding thresholds for providing support

Cerebral visual impairment (CVI) is the most common cause of visual impairment in children in the United Kingdom. The mainstay of management is providing strategies and environment adaptations to allow the child to use their vision for learning and independence. It is therefore important to understand educational access policies to facilitate timely and appropriate referral to qualified teachers for learners with visual impairment (QTVI) by ophthalmologists. QTVIs were recruited from VIEW (Visual Impairment England and Wales) and the Scottish Sensory Centre (QTVI organisations) via email, newsletter and social media. Respondents were directed to an online electronic questionnaire. 116 responses were received; this represents around 18% response rate. All services accepted referrals for children with cerebral visual impairment (CVI). The majority of services (97%) did not have a strict visual acuity threshold for children with CVI. There is an inconsistent approach in the diagnosis of CVI across the United Kingdom, with some QTVI expressing concern that this had prevented children with visual dysfunction from accessing help. QTVI indicated they would welcome more referrals for Cerebral VI, at an earlier age, and that a formalised referral pathway would be beneficial. Children with CVI are accepted for support by QTVI/sensory services regardless of visual acuity. Some services welcomed referrals for children undergoing assessment where CVI had yet to be confirmed. However, the formal diagnosis of CVI by an ophthalmologist as a pre-requisite to access services in other areas emphasises the need to improve clinicians’ confidence in the diagnosis of CVI. Ophthalmologists are encouraged to engage with local QTVI/sensory teams to facilitate exchange of information and appropriate and timely referral of children in need.

The Developmental Eye Movement Test Does Not Detect Oculomotor Problems: Evidence from Children with Nystagmus.

SIGNIFICANCEThe Developmental Eye Movement (DEM) test, a test purported to assess oculomotor skills, does not detect eye movement disorder in nystagmus syndromes. The test should not be used for the clinical evaluation of oculomotor disorders.PURPOSEThe DEM test ratio compares a horizontal number naming subtest with a vertical one to identify oculomotor problems independent of a child's visual-verbal naming skills. Here, we tested the construct validity of this method by comparing scores of children with and without pathologic nystagmus. Such a nystagmus disturbs normal fixation and saccadic behavior because of the presence of involuntary rhythmic oscillations of the eyes. Therefore, if the ratio is indeed a comprehensive measure of oculomotor problems, children with nystagmus should show an increased ratio score.METHODSThe DEM test performances of normally sighted children (n = 94), children with ocular visual impairments (VIo; n = 33), and children with cerebral visual impairment (n = 30) were analyzed using linear regression. Part of the children with VIo and cerebral visual impairment had either fusion maldevelopment nystagmus syndrome (n = 8) or infantile nystagmus syndrome (n = 20), whereas the others showed no pathologic nystagmus.RESULTSThe times needed for the horizontal and vertical subtests were significantly different between children with normal vision, VIo, and cerebral visual impairment (P < .001). However, the presence of nystagmus did not add significantly to the horizontal and vertical times (P > .20), nor did it have an effect on the ratio (P > .10).CONCLUSIONSThe DEM test ratio is not sensitive to fixation and saccade abnormalities associated with nystagmus, indicating that it does not have general construct validity to detect true eye movement disorders. Although not suitable for the evaluation of oculomotor disorders, the subtests do have clinical relevance in the diagnosis of cerebral visual impairment.

EVALUATION OF VARIOUS CAUSES OF CEREBRAL VISUAL IMPAIRMENT IN CHILDREN AT TERTIARY CARE CENTRE

Purpose: The purpose of this study is to evaluate the etiology, associated ophthalmological and neurological ndings of cerebral visual impairment (CVI) in children at a tertiary care center. Methods: A retrospective study was conducted on 71 patients visiting between February 2020 to August 2021 at a tertiary care hospital, J.L.N. medical college and hospital, Ajmer, Rajasthan. Diagnosis of CVI was based on ocular examination found poor visual function that could not be accounted by age, ocular ndings and neuroimaging.Results: The records of 44 boys and 27 girls were analysed. Majority of them were &lt;3yrs (40.8%) . The most common etiology was perinatal hypoxia (29%), followed by prematurity (22.5%). Moreover, 9(12.7%) showed mixed aetiology, 8(11.3%) had hydrocephalus and 7(9.9%) had hypoglycemia . Amongst the ocular associations, refractive error was the most common, seen in 32 (45%) children, while strabismus in 31 (44%), nystagmus in 22(31%). Thirty two (45%) children had associated developmental delay, while 38(53%) had seizures. The most common ndings were ischemic encephalopathy (31%), periventricular leukomalacia (23%), cortical and subcortical atrophy and structural malformations (24%). Conclusion: CVI is of increasing importance as a cause of vision impairment in children. The major causes for CVI tend to be perinatal hypoxia followed by prematurity. Establishing the etiology for these children at early age may aid in early rehabilitation of these children.

Profiling children with cerebral visual impairment in a tertiary eye care center

Background: Cerebral visual impairment (CVI) is a bilateral visual impairment that affects children in all industrialized countries. It has become more common in low-income countries as a result of the increased survival rates of children who suffer from severe neurological conditions during the perinatal period. The purpose of this study was to determine the characteristics of children with CVI in a tertiary children’s eye care center population. Methods: From October 2020 to September 2021, a cross-sectional study was conducted to select all consecutive patients with a diagnosis of cerebral visual impairment aged 6 months to 16 years. On the neurological deficit, information was gathered from the patient’s referral: parental interviews, observations, and direct assessment were used for functional vision characteristics, and an ophthalmic examination was performed for eye findings. The interviewees’ responses were matched to the ten specific behavioral characteristics shared by children with CVI. Cortical visual impairment was diagnosed using three criteria: [the vision loss is not explained by abnormalities found on the eye examination, a neurological medical diagnosis, and the child exhibits one of the unique visual and behavioral characteristics described by Roman Lantz]. A descriptive statistical analysis (frequency, mean, and range) was calculated. Results: Forty children with CVI (1.96% of total children) were seen. The mean age was 2.56 ( 1.98) years. There were 24 (60%) males. On a referral paper of 28, hypoxic-ischemic encephalopathy was the commonest cause mentioned (70.0%). Seizures were the most frequent neurological deficit at presentation. Ophthalmic and neurologic impairments were found in 42.5% of children with CVI. Based on Roman-Lantzy’s three phases of the CVI Range, 90% of children with CVI at the test time had Phase I or Phase II vision. Conclusion: According to the findings of this study, visual impairment is critical in the diagnosis of CVI. The prevalence of CVI as a cause of childhood vision impairment is significant. Hypoxic-ischemic encephalopathy is the most common cause of CVI. All children with CVI have serious neurological issues, and the majority have associated ophthalmic abnormalities.

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

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

Evaluation of the Relationship Between Preferential Looking Testing and Visual Evoked Potentials as a Biomarker of Cerebral Visual Impairment.

Cerebral visual impairment (CVI) is a leading cause of visual impairment in children in developed countries, but diagnostic tools to detect CVI are limited. We sought to analyze the visual acuity of children with CVI as assessed by visual evoked potentials (VEPs) and preferential looking test (PLT) to determine whether the relationship between the visual outcomes on these two testing methods may serve as a biomarker of CVI. We performed a retrospective chart review of patients with a confirmed diagnosis of CVI and at least one ophthalmological assessment with visual acuity measured by VEP and PLT. Of the 218 patients included in the study, the most common condition associated with CVI was an underlying genetic disorder (36%, 79/218). Treatment for seizures occurred in the majority of the entire cohort of patients (80%, 175/218). Ophthalmic comorbidities included retinal disease in 23 patients, optic nerve disease in 68 patients, nystagmus in 78 patients, and strabismus in 176 patients. When assessed by either VEP or PLT, visual acuity in children with CVI fell below expected norms. At initial and final presentations, VEP acuity exceeded PLT acuity by one or more octaves, and this difference was greater than expected compared with normal visual development. We propose utilizing this quantifiable disparity between VEP and PLT as a biomarker of CVI.

Informisanost oftalmologa o cerebralnom oštećenju vida - preliminarno istraživanje

Introduction. Cerebral visual impairment is the leading cause of severe visual impairment and blindness in infants and children in high-income countries. The main cause of this condition is damage of higher visual pathways and brain centers which leads to problems in processing visual information. In the last 20 years, an increase in the prevalence of cerebral visual impairment has been observed, but this diagnosis as a cause of vision problems in Serbia is not common. Objectives. The aim of this study was to assess the awareness of ophthalmologists of cerebral visual impairment. Methods. The Questionnaire for the assessment of cerebral visual impairment (Maitreya et al., 2018) was translated into Serbian, and used for data collection. The sample consisted of 45 ophthalmologists employed on the territory of the Republic of Serbia. Results. Two thirds of ophthalmologists from the sample self-assessed their knowledge a slow (or nonexistent). However, the results showed that they had a satisfying level of awareness about cerebral visual impairment, and the majority of the participants correctly stated the most common risk factor for cerebral visual impairment. The highest awareness was observed in ophthalmologists who worked in health centers, those with more work experience, and especially those who primarily worked with children. Conclusion. Further informing the ophthalmologists about the diagnostic method of choice, symptomatology and differential diagnosis of cerebral visual impairment is desirable. Raising the awareness of doctors about this condition would lead to more frequent diagnoses, especially in babies with neurological impairments that are currently most likely misdiagnosed or unrecognized when it comes to their vision problems.

Ophthalmologic approach to babies with cerebral visual impairment.

Cerebral visual impairment (CVI) is an increasingly common type of visual disturbance in infants and children. The increased incidence is associated with improved neonatal intensive care services and survival of premature infants, especially in developed countries and our country. For accurate ophthalmological evaluation, it is important to know the behavioral responses to visual stimuli that are unique to CVI such as color preference, need for movement, visual latency, visual field preference, and difficulty in visual complexity. This review is prepared to draw attention to the subject within the scope of Ankara University Vision, Artificial Vision and Low Vision Rehabilitation training programs. The most common causes are hypoxia and perinatal ischemia. Ocular structures are generally normal or are not sufficient to explain the visual impairment. Diagnosis and habilitation methods differ from visual impairment of ocular origin. As a result, early diagnosis of CVI in infants and toddlers and an effective visual habilitation with a multidisciplinary approach where ophthalmologists and pediatricians lead the team is very valuable. Early diagnosis and early visual habilitation will increase the quality of life of babies and will provide important gains for families and therefore the whole society. Pediatricians should be familiar with this group of disturbances and the available resources, as they are best placed to refer the child for evaluation and rehabilitation and encourage the family for follow-up.

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

PurposeCerebral visual impairment (CVI) is the leading cause of childhood visual impairment in the developed world. Despite this, there are no agreed clinical guidelines for the investigation and diagnosis of the condition. Before development of such guidelines can commence, it is important to recognise which approaches are currently employed. This systematic review evaluated the literature to identify which methods of assessment are currently used to investigate and diagnose childhood CVI.MethodsMedline, Embase, CINAHL, Scopus and the Cochrane Library databases were systematically searched in January 2020 using defined search terms. Articles were included if they: (i) were research papers, conference abstracts or research protocols published in peer‐reviewed scientific journals, or relevant textbooks; (ii) included a clinical investigation of CVI in children; (iii) provided an explanation or criteria to diagnose CVI and (iv) were specifically investigating cerebral/cortical visual impairment. Methods used to a) assess and b) diagnose CVI were extracted from included articles. ‘Assessment scores’ were assigned for each method employed by researchers to investigate and diagnose CVI to quantify and compare approaches between articles. A quality grading was also applied to each article.ResultsOf 6454 identified articles, 45 met the inclusion criteria. From these, 10 categories of assessment utilised within included articles were identified: (1) Medical history, (2) Vision assessment/ophthalmologic examination, (3) Neuroimaging, (4) Visual behaviour and direct observation, (5) Structured history‐taking, (6) Visual perception tests, (7) Ocular movement and posture assessment, (8) Intelligence/IQ assessment, (9) Clinical electrophysiology and (10) Neurodevelopmental tests. In terms of diagnostic criteria, the most commonly reported approach was one of exclusion, i.e., CVI was diagnosed when visual dysfunction could not be attributed to abnormalities detected in the anterior visual pathway.ConclusionThere is a lack of common practice in the approaches used by clinicians to investigate and diagnose CVI in children. At present, a ‘diagnosis of exclusion’ remains the most common means to diagnose CVI. Development of clinical guidelines for assessment and diagnosis are necessary to ensure consistency in the diagnosis of CVI and the timely implementation of support to alleviate the impact of CVI on the child’s daily living.

Towards population screening for Cerebral Visual Impairment: Validity of the Five Questions and the CVI Questionnaire.

IntroductionCerebral Visual Impairment (CVI) is the most common cause of visual impairment in children in the developed world and appears to be more prevalent in children with additional support needs (ASN). There is an urgent need for routine screening for CVI, particularly in children with ASN, however, current screening questionnaires for CVI have limited validation. The aim of this study was to evaluate two screening tools: the Five Questions and the CVI Questionnaire. Additionally, the distribution of CVI across neurodevelopmental disorders is unknown. This too was investigated.MethodsAn online survey was completed by 535 parents. The survey was advertised via social media, CVI websites and parent email systems of four schools. The survey comprised of the Five Questions, the CVI Questionnaire and additional questions regarding the child’s diagnoses. Whether or not a child had a diagnosis of CVI and/or additional neurodevelopmental disorders was based on parental report.ResultsBased on parent reports, both the screening tools accurately screened for CVI diagnoses in children. The Five Questions and the CVI Questionnaire have construct validity (as determined through factor analysis), high internal consistency (as determined by Cronbach’s alpha) and convergent validity (as determined by correlation analysis of the raw scores of each questionnaire). This study also highlights that among children with neurodevelopmental disorders, a large proportion have parent-reported CVI (23%-39%) and potential CVI (6.59–22.53%; as identified by the questionnaires).ConclusionThe current study demonstrates that the Five Questions and CVI Questionnaire have good convergent validity, internal consistency and a reliable factor structure and may therefore be suitable as screening tools. The study also highlights that reported or potential CVI is evident in a large proportion of children with neurodevelopmental disorders.

Cerebral visual impairment in children: Causes and associated ophthalmological problems.

Purpose:The aim of this study is to identify common causes, associated ophthalmological abnormalities, and systemic comorbidities in children in Andhra Pradesh, India, with cerebral visual impairment (CVI).Methods:A retrospective review of case records of all children aged <16 years with diagnosis of CVI seen between January 2016 and December 2016 was carried out. Data were collected for their age, gender, cause of CVI, refraction, accommodation, anterior and posterior segment examination findings, and systemic problems.Results:A total of 124 patients were identified and studied (80 boys and 44 girls, mean age 5.23 years, 44.8% aged <2 years). The most common causes of CVI were hypoxic–ischemic encephalopathy (HIE) (34.4%), undetermined etiology (32.8%), neonatal seizures, and infantile spasms (16% each). The most common presenting complaints were poor vision (76%) and squint (11.2%). Profound visual impairment was seen in 88.8%, and 11.2% had high functioning CVI. Fifty-eight (46.4%) patients had significant refractive errors, 40 (32.25%) had strabismus, 4 (3.2%) had visually significant cataract, and 40 (32%) had optic atrophy. Motor delay was observed in 39.5%, speech delay was evident in 22.4%, and cognitive delay in 16%.Conclusion:HIE is the most common cause (one-third) of CVI in our population, and the majority of them presented at age <2 years (44.8%) with profound visual impairment (88.8%). A significant number of them have treatable ophthalmic conditions such as refractive errors (46.4%), accommodative insufficiency (12.1%), and cataract (3.2%), and more than one-third of them also have delay in other areas of development.

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

Cerebral Visual Impairment (CVI) is a leading cause of vision impairment in developed and developing countries due to and increased survival of preterm and low birth weight infants. There are few data concerning the validity of protocols available to diagnose CVI. This study aimed to document the face, content and construct validity of an assessment protocol namely, a 15-domain, Structured Clinical Question Inventory (SCQI), which is based on structured history taking and clinical examination, for the diagnosis of CVI in a clinical population of India. This study was a retro-spective chart analysis of all children below the age of 18years, referred to the CVI clinic of a tertiary care teaching hospital in Southern India from March 2011-Feb 2012. Clinical case-notes including the SCQI findings of all children referred to the clinic were reviewed. The data were extracted after Institutional Review Board approval. Pearson correlation coefficient, Cronbach's alpha and exploratory factor analysis were used to document the content and construct validity of the examination protocol. A total of 342 children (35.7% male, 64.3% female), with a mean age of 3.8 years (range 0-17 years, the median was 3 years) were included in the study and their data were examined. The internal consistency of the SCQI was 0.93 suggesting it as an excellent tool to characterise and profile CVI and a 2-factor model (Dorsal Stream Dysfunction and Ventral Stream Dysfunction) based on a biologically plausible model explained 63% of the variance. The results of using the SCQI affirm published data and endorse a theoretical construct similar across cultures. The potential diagnostic accuracy, reliability and utility of this measure for CVI needs to be studied further. The clinical use of a short version of the SCQI may be helpful to contribute to the identification of CVI, especially for middle and low-income countries.

The relationship between visual orienting responses and clinical characteristics in children attending special education for the visually impaired.

We recently introduced a method based on quantification of orienting responses toward visual stimuli to assess the quality of visual information processing in children. In the present study, we examined the relationship between orienting responses and factors that are associated with visual processing impairments in current clinical practice. Response time and fixation quality to visual features such as form, contrast, motion, and color stimuli were assessed in 104 children from 1 to 12 years attending special education for the visually impaired. Using regression analysis, we investigated whether these parameters were affected by clinical characteristics of children. Response times significantly depended on stimulus type. Responses to high-contrast cartoons were significantly slower in children with a clinical diagnosis of cerebral visual impairment. Fixation quality was significantly affected by visual acuity and nystagmus. The results suggest that the quantitative measurement of orienting responses is strongly related to cerebral visual impairment in children.

The spectrum of cerebral visual impairment as a sequel to premature birth: an overview

In children born prematurely, impairment of vision due to damage to the brain is more common than due to retinopathy of prematurity. Yet, the diagnosis of cerebral visual impairment may be missed. The subject of cerebral visual impairment in children is reviewed in order to explain and draw attention to the types of visual deficits and behaviours that may result as a sequel to premature birth. A wide range of sources of data has been employed to assemble this overview. The principal reference source is PubMed. The material presented highlights the origin and range of visual deficits that result from damage to the brain, related to premature birth. Deficits of primary visual functions, perceptual dysfunction, simultanagnostic visual disorders and impaired visual guidance of movement (optic ataxia), as well as disorders of visual attention and memory, can occur in a variety of combinations and degrees. The resulting behavioural outcomes are described. Identification and characterisation of impaired vision, due to prematurity associated damage to the brain, are essential. This is required so as to ensure that affected children are not inappropriately disadvantaged on account of the diagnosis being missed or inadequately acted upon, but instead, they are managed optimally, both at home and at school, so that their development is enhanced to the greatest advantage.

Diagnosing Cerebral Visual Impairment in Children with Good Visual Acuity

Purpose: To identify elements that could facilitate the diagnosis of cerebral visual impairment (CVI) in children with good visual acuity in the general ophthalmic clinic.Methods: We retrospectively investigated the clinical characteristics of 30 children with good visual acuity and CVI and compared them with those of 23 children who were referred with a suspicion of CVI, but proved to have a different diagnosis. Clinical characteristics included medical history, MRI findings, visual acuity, crowding ratio (CR), visual field assessment, and the results of ophthalmologic and orthoptic examination. We also evaluated the additional value of a short CVI questionnaire.Results: Eighty-three percent of the children with an abnormal medical history (mainly prematurity and perinatal hypoxia) had CVI, in contrast with none of the children with a normal medical history. Cerebral palsy, visual field defects, and partial optic atrophy only occurred in the CVI group. 41% of the children with CVI had a CR ≥2.0, which may be related to dorsal stream dysfunction. All children with CVI, but also 91% of the children without CVI gave ≥3 affirmative answers on the CVI questionnaire.Conclusion: An abnormal pre- or perinatal medical history is the most important risk factor for CVI in children, and therefore in deciding which children should be referred for further multidisciplinary assessment. Additional symptoms of cerebral damage, i.e., cerebral palsy, visual field defects, partial optic atrophy, and a CR ≥2 may support the diagnosis. CVI questionnaires should not be used for screening purposes as they yield too many false positives.

Effects of visual processing and congenital nystagmus on visually guided ocular motor behaviour

The aim of this study was to compare visually guided ocular motor behaviour in children with visual processing and/or motor deficits with an age-matched comparison group and an adult group. Visual stimuli were shown to 28 children with visual processing and/or motor deficits (11 females, 17 males; mean age 7y 5mo, SD 2y 9mo, range 2-14y;) and an age-matched comparison group of 213 typically developing children (115 females, 98 males; mean age 5y 8mo, SD 3y 5mo, range 0-12y). The adult group consisted of nine females and two males with (mean age of 24y 4mo, SD 4y 8mo). Individuals who had a likely diagnosis of cerebral visual impairment (CVI), an opticopathy with unknown location, nystagmus, glaucoma, or a cataract were included in the study. Exclusion criteria were a visual acuity below 0.2, a developmental age under 1 year, and the presence of brain tumours, autism, and anxiety disorders. Orientating eye movements to large cartoons were quantified using the reaction time to fixation (RTF) and gaze fixation area (GFA). A Mann-Whitney U test was used to compare the differences between groups and Bonferroni post-hoc testing was used to analyse age dependence of RTF and GFA values within the comparison group. Individuals with CVI showed significantly prolonged RTF values; those with congenital nystagmus showed significantly increased GFA values. In the comparison group, RTF was significantly longer in children under the age of 2 years than in children aged 4 years and older (290 and 200 ms respectively; p < 0.001). No developmental change was found for GFA values. Increased RTF values in individuals with CVI relate to visual processing deficits. The data suggest that visually guided ocular motor responses mature during the first 3 years of life.

Developing the University Curriculum to Include CVI: A Work in Progress at the University of Arizona

One of the most complex decisions of the first year of teaching for teachers of students with visual impairments is how to serve children with severe and multiple disabilities effectively. These children typically have a visual diagnosis of cerebral visual impairment (CVI), but their learning characteristics and needs go far beyond their use of vision. Over the past 30 years, university students in visual impairment have needed and received increased preparation to meet the needs of children with CVI. Like other universities, the University of Arizona has steadily incorporated more information about the visual needs of children with CVI into its curriculum to prepare teachers of students with visual impairments and orientation and mobility (OM the focus has expanded from study of the optical system to providing a broader understanding of the neurological system. For Dr. Topor, the works of Gordon Dutton and Lea Hyvarinen were particularly important as she reframed our curriculum; university students must now understand not only the variability of vision, but the reasons why children with CVI are more different from one another than are those with other visual conditions. To include this area in our curriculum means that students may spend a little less time learning about the anatomy of the eye and a little more time understanding how the eye and brain connect. In our teaching methods course, the balance has shifted slightly toward the ways in which children with significant multiple disabilities learn; these students are most often those with CVI. In addition to understanding the roots of CVI, future teachers must also learn to make difficult decisions related to intervention. Studies by Christine Roman, Amanda Lueck, Mary Morse, and others have been carefully examining students' behaviors and responses in order to document effects. However, teachers in practice often find that they have limited time in which to implement a consistent program, especially if they are itinerant; the child who makes little progress may need more intense intervention and a more meaningful context, or may not have the visual ability to respond visually regardless of intervention. The decisions about the extent and type of visual intervention are not clear cut, so how can we guide future teachers to make the best decisions? …