Higher Visual Function Deficits in Children With Cerebral Visual Impairment and Good Visual Acuity.
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ABSTRACT: 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.
Project description: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.
Project description:One of the characteristics of children with cerebral visual impairments (CVI) is that they need more time to process visual information. However, currently, few tests are available that can reliably measure visual processing speed. The speed acuity test, a discrimination reaction-time test in which participants indicate the orientation of Landolt-C symbols as quickly and accurately as possible, was specifically developed to determine the time a child needs to discern visual details. The test measures both the accuracy and the latency of the responses for nine different optotype sizes in order to control for decreased visual acuity. The results show that children with CVI need significantly more time to respond to the largest optotype sizes than age-matched normally sighted children and children with visual impairments due to an ocular disorder (VIo). This effect is independent of the time it takes to make a motor response. However, the reaction-time difference between the children with CVI and VIo is not seen for optotype sizes at the acuity threshold. Together with reaction times on visual and auditory detection tasks as controls, reaction times measured in the speed-acuity test allow for acceptable discrimination (AUC in ROC analysis: 0.81) between CVI and VIo.
Project description:The purpose of this study was to investigate the effectiveness of visual rehabilitation of a computer-based visual stimulation (VS) program combining checkerboard pattern reversal (passive stimulation) with oddball stimuli (attentional modulation) for improving the visual acuity (VA) of visually impaired (VI) children and children with amblyopia and additional developmental problems. Six children (three females, three males; mean age = 3.9 ± 2.3 years) with impaired VA caused by deficits along the anterior and/or posterior visual pathways were recruited. Participants received eight rounds of VS training (two rounds per week) of at least eight sessions per round. Each session consisted of stimulation with 200 or 300 pattern reversals. Assessments of VA (assessed with the Lea symbol VA test or Teller VA cards), visual evoked potential (VEP), and functional vision (assessed with the Chinese-version Functional Vision Questionnaire, FVQ) were carried out before and after the VS program. Significant gains in VA were found after the VS training [VA = 1.05 logMAR ± 0.80 to 0.61 logMAR ± 0.53, Z = -2.20, asymptotic significance (2-tailed) = 0.028]. No significant changes were observed in the FVQ assessment [92.8 ± 12.6 to 100.8 ±SD = 15.4, Z = -1.46, asymptotic significance (2-tailed) = 0.144]. VEP measurement showed improvement in P100 latency and amplitude or integration of the waveform in two participants. Our results indicate that a computer-based VS program with passive checkerboard stimulation, oddball stimulus design, and interesting auditory feedback could be considered as a potential intervention option to improve the VA of a wide age range of VI children and children with impaired VA combined with other neurological disorders.
Project description:PurposeWe report the case of an 11-year-old boy with posterior microphthalmos who exhibited normal and age appropriate development of visual acuity.ObservationsAt the initial diagnosis, when he was 3 years old, the best-corrected visual acuity (BCVA) was 20/125 in the right eye (OD) and 20/200 in the left eye (OS) with high hyperopia (cycloplegic refraction +15.75 D sphere OD and +16.25 D sphere OS). Eight years after he began wearing hyperopic glasses, BCVA was 20/16 OD and 20/20 OS. Optical coherence tomography did not reveal a foveal pit in either eye throughout the observation period. However, elongation of the outer segment and widening of the outer nuclear layers were observed.Conclusion and importanceMany cases of posterior microphthalmos demonstrate subnormal BCVA due to an abnormal foveal structure (papillomacular retinal folds, absence of the foveal pit and avascular zone) and high hyperopia. However, if foveal maturity progresses, even if the foveal structure is abnormal, early aggressive amblyopia treatment can result in normal and age appropriate development of visual acuity.
Project description: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.
Project description:PurposeTo explore the objective functional visual outcomes of cataract surgery in patients with good preoperative visual acuity.MethodsWe enrolled 130 cataract patients whose best-corrected visual acuity (BCVA) was 20/40 or better preoperatively. Objective visual functions were evaluated with a KR-1W analyzer before and at 1 month after cataract surgery.ResultsThe nuclear (N), cortical (C), and N+C groups had very high preoperative ocular and internal total high-order aberrations (HOAs), coma, and abnormal spherical aberrations. At 1 month after cataract surgery, in addition to the remarkable increase of both uncorrected visual acuity and BCVA, both ocular and internal HOAs in the three groups decreased significantly after cataract surgery (all P<0.05). Point spread function and modulation transfer functions were also improved significantly in these patients (all P<0.05).ConclusionsThe objective functional vision of patients with 20/40 or better preoperative BCVA improved significantly after cataract surgery. This finding shows that the arbitrary threshold of BCVA worse than 20/40 in China cannot always be used to determine who will benefit from cataract surgery.
Project description:BackgroundCerebral Visual Impairment (CVI) is a very common finding in children affected by Cerebral Palsy (CP). In this paper we studied the characteristics of CVI of a large group of children with CP and CVI, describing their neurovisual profiles according to three different age subgroups (subgroup 1: infants 6 months-2 years; subgroup 2: pre-school age 3-5 years; subgroup 3: school age ≥ 6 years).MethodsWe enrolled 180 subjects (104 males, mean age 66 ± 42.6 months; range 6-192 months) with CP and CVI for the study. We carried out a demographic and clinical data collection, neurological examination, developmental or cognitive assessment, and a video-recorded visual function assessment including an evaluation of ophthalmological characteristics, oculomotor functions, and basic visual functions. In school-aged children, we also performed an evaluation of their cognitive-visual profiles.ResultsThere were signs of CVI in all the three subgroups. Subgroup 1 (62 children) and subgroup 2 (50 children) were different for fixation (p = 0.02), visual acuity (p = 0.03) and contrast sensitivity (p < 0.01), being more frequently impaired in younger children. Comparing subgroup 2 with subgroup 3 (68 children), the older children presented more frequently myopia (p = 0.02) while the younger ones esotropia (p = 0.02) and alteration in smooth pursuit (p = 0.03) and saccades (p < 0.01). Furthermore, fixation, smooth pursuit, visual acuity, contrast sensitivity and visual filed (p < 0.01) were more frequently impaired in younger children (subgroup 1) compared to the older ones. Multiple correspondence analysis (MCA) confirmed the different neurovisual profiles according to age: younger children with CP showed more signs of CVI compared to the older ones. 34 out of 68 children belonging to subgroup 3 underwent the cognitive visual evaluation; an impairment of cognitive visual skills was detected in 21 subjects.ConclusionYounger children with CP showed more signs of CVI compared to the older ones, likely for the physiological maturation of visual system and mechanisms of neuroplasticity. In this direction, we suggest an early neurovisual evaluation to detect any weak visual functions.
Project description:BackgroundLongitudinal evidence of poor visual acuity associating with higher risk of incident dementia is mixed. This study aimed to examine if poor visual acuity was associated with higher dementia incidence in a large community cohort of older adults, independent of the possible biases relating to misclassification error, reverse causality, and confounding effects due to health problems and behaviors.MethodsA total of 15,576 community-living older adults without dementia at baseline were followed for 6 years to the outcome of incident dementia, which was diagnosed according to the ICD-10 or a Clinical Dementia Rating of 1 to 3. Visual acuity was assessed using the Snellen's chart at baseline and follow-up. Important variables including demographics (age, sex, education, and socioeconomic status), physical and psychiatric comorbidities (cardiovascular risks, ophthalmological conditions, hearing impairment, poor mobility, and depression), and lifestyle behaviors (smoking, diet, physical, intellectual, and social activities) were also assessed.ResultsOver 68,904 person-years of follow-up, 1,349 participants developed dementia. Poorer visual acuity at baseline was associated with higher dementia incidence in 6 years, even after adjusting for demographics, health problems, and lifestyle behaviors, and excluding those who developed dementia within 3 years after baseline. Compared with normal vision, the hazard ratio of dementia was 1.19 (p = .31), 2.09 (p < .001), and 8.66 (p < .001) for mild, moderate, and severe visual impairment, respectively.ConclusionsModerate-to-severe visual impairment could be a potential predictor and possibly a risk factor for dementia. From a clinical perspective, older adults with poor visual acuity might warrant further risk assessment for dementia.
Project description:BACKGROUND/OBJECTIVES:To evaluate the long-term progression of idiopathic epiretinal membranes (iERMs) with good baseline visual acuity, and to identify predictors of visual decline. DESIGN:Retrospective case series SUBJECTS METHODS: We reviewed records of 145 eyes with iERM and best-corrected visual acuity (BCVA) of 20/40 or greater at presentation, including BCVA, lens status, and central macular thickness (CMT) at yearly visits; as well as anatomic biomarkers including vitreomacular adhesion, pseudohole, lamellar hole, intraretinal cysts, disorganization of the inner retinal layers (DRIL), and disruption of outer retinal layers. Linear mixed effects and mixed-effects Cox proportional hazards models were used to identify clinical and anatomic predictors of vision change and time to surgery. RESULTS:At presentation, mean BCVA was 0.17?±?0.10 logMAR units (Snellen 20/30) and mean CMT was 353.3?±?75.4??m. After a median follow-up of 3.7 years (range 1-7 years), BCVA declined slowly at 0.012?±?0.003 logMAR units/year, with phakic eyes declining more rapidly than pseudophakic eyes (0.019?±?0.003 vs. 0.010?±?0.004 logMAR units/year). Metamorphopsia, phakic lens status, lamellar hole, and inner nuclear layer cysts were associated with faster visual decline. Cumulative rates of progression to surgery were 2.9, 5.6, 12.2, and 21.1% at years 1-4. Visual symptoms, metamorphopsia, greater CMT, and disruption of outer retinal layers were associated with greater hazard for surgery. CONCLUSION:Eyes with iERM and visual acuity???20/40 experience slow visual decline, with 21% of eyes requiring surgery after 4 years. Clinical and anatomic predictors of vision loss may be distinct from factors associated with earlier surgical intervention.