Subnormal visual perception in school-aged ex-preterm patients in a paediatric eye clinic

Comprehensive Assessment of Visual Perceptual Skills in Autism Spectrum Disorder

The purpose of the current study was to assess meaningful variability in visual-perceptual skills using a standardized assessment of visual perception, the Test of Visual Perceptual Skills (TVPS), across children with and without autism spectrum disorder (ASD). In addition to assessing overall accuracy across subtests of the TVPS, we also assessed response variability at the item-level, and the linear relationship between quantitative measures of ASD symptoms, task performance, and item-level variance. We report a significant linear relationship between ASD features and performance on the TVPS Figure Ground subtest. Additionally, results of an item-level analysis point to a significant relationship between within-task variability on the Figure Ground subtest and quantitative ASD traits, with a less variable response pattern being associated with increased ASD symptoms. Findings presented here suggest variability in perceptual processing across ASD may be influenced by individual differences in trait distribution.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Basic visual perceptual processes in children with typical development and cerebral palsy: The processing of surface, length, orientation, and position

The present study aims to assess how the processing of basic visual perceptual (VP) components (length, surface, orientation, and position) develops in typically developing (TD) children (n = 215, 4-14 years old) and adults (n = 20, 20-25 years old), and in children with cerebral palsy (CP) (n = 86, 5-14 years old) using the first four subtests of the Battery for the Evaluation of Visual Perceptual and Spatial processing in children. Experiment 1 showed that these four basic VP processes follow distinct developmental trajectories in typical development. Experiment 2 revealed that children with CP present global and persistent deficits for the processing of basic VP components when compared with TD children matched on chronological age and nonverbal reasoning abilities.

Should we add visual acuity ratios to referral criteria for potential cerebral visual impairment?

PURPOSE

To determine whether the assessment of visual acuity ratios might improve the referral of children with (sub)normal visual acuity but at risk of cerebral visual impairment.

METHODS

In an exploratory study, we assessed visual acuity, crowding ratio and the ratios between grating acuity (Teller Acuity Cards-II) and optotype acuity (Cambridge Crowding Cards) in 60 typically developing school children (mean age 5y8m±1y1m), 21 children with ocular abnormalities only (5y7m±1y9m) and 26 children with (suspected) brain damage (5y7m±1y11m). Sensitivities and specificities were calculated for targets and controls from the perspective of different groups of diagnosticians: youth health care professionals (target: children with any visual abnormalities), ophthalmologists and low vision experts (target: children at risk of cerebral visual impairment).

RESULTS

For youth health care professionals subnormal visual acuity had the best sensitivity (76%) and specificity (70%). For ophthalmologists and low vision experts the crowding ratio had the best sensitivity (67%) and specificity (79 and 86%).

CONCLUSION

Youth health care professionals best continue applying subnormal visual acuity for screening, whereas ophthalmologists and low vision experts best add the crowding ratio to their routine diagnostics, to distinguish children at risk of visual impairment in the context of brain damage from children with ocular pathology only.

Visual-perceptual impairment in children with cerebral palsy: a systematic review

AIM

Visual perception is one of the cognitive functions often impaired in children with cerebral palsy (CP). The aim of this systematic literature review was to assess the frequency of visual-perceptual impairment (VPI) and its relationship with patient characteristics.

METHOD

Eligible studies were relevant papers assessing visual perception with five common standardized assessment instruments in children with CP published from January 1990 to August 2011.

RESULTS

Of the 84 studies selected, 15 were retained. In children with CP, the proportion of VPI ranged from 40% to 50% and the mean visual perception quotient from 70 to 90. None of the studies reported a significant influence of CP subtype, IQ level, side of motor impairment, neuro-ophthalmological outcomes, or seizures. The severity of neuroradiological lesions seemed associated with VPI. The influence of prematurity was controversial, but a lower gestational age was more often associated with lower visual motor skills than with decreased visual-perceptual abilities.

INTERPRETATION

The impairment of visual perception in children with CP should be considered a core disorder within the CP syndrome. Further research, including a more systematic approach to neuropsychological testing, is needed to explore the specific impact of CP subgroups and of neuroradiological features on visual-perceptual development.

Compromised approximate number system acuity in extremely preterm school-aged children

AIM

The aim of this study was to compare the approximate number system acuity in children born extremely preterm aged 6 years 6 months and typically developing, age-matched peers.

METHOD

This population-based follow-up study included 65 children born before 27 gestational weeks (35 males, 30 females; mean gestational age 25.4 wks [SD 1.1 wk]; mean birthweight 789 g [SD 158 g]) and 47 typically developing children (24 females, 23 males) at the age of 6 years 6 months. A battery of cognitive tests was administered, including a computerized test for measuring approximate number system acuity and tests for general cognition, working memory, processing speed, and visual attention. Approximate number system outcome measures were means of Weber fraction (w) values and response time in milliseconds.

RESULTS

The 43 extremely preterm children in whom usable data were obtained performed significantly worse than the typically developing children on the approximate number system task (w=0.30 [SD 0.23] vs. 0.17 [SD 0.13]; p=0.003) and were significantly slower (response time=2934 ms [SD 1102 ms] vs 2376 ms [SD 310 ms]; p=0.002). The differences remained when adjusting for differences in other cognitive functions (p=0.03).

INTERPRETATION

Preterm birth has a negative impact on an individual's ability to rapidly approximate and compare numbers of visually presented items. This deficiency is thought to be a consequence of dorsal stream dysfunction. Future studies will investigate whether this deficiency is correlated with lower mathematical proficiency in this group of children.

Early postnatal growth variables are related to morphologic and functional ophthalmologic outcome in children born preterm

AIM

To evaluate the association between gestational age (GA), early and late postnatal growth variables and ophthalmologic outcome in ex-preterm children. methods: Children (GA < 32 weeks, n = 66), previously examined regarding insulin-like growth factor 1 (IGF-1) serum concentrations in relation to ROP, underwent ophthalmologic examination at median 5.6 years. Weight, height, and head circumference (HC) were measured and expressed as SDS. Growth variables were analysed in relation to ophthalmologic outcome.

RESULTS

At follow-up 74% had some ophthalmologic abnormality and 17% had visual impairment. Poor visual acuity was correlated with low GA (r(s) = 0.29, p = 0.019), low weight at 32 weeks (r(s) = 0.30, p = 0.013), and low weight (r(s) = 0.37, p = 0.0025), height (r(s) = 0.41, p = 0.0007) and HC (r(s) = 0.55, p < 0.0001) at follow-up. Hyperopic children (25%) had low neonatal IGF-1 (p = 0.0096) and HC at follow-up (p = 0.022). Poor visual perception was correlated with low early weight (r(s) = 0.38, p = 0.0036) and HC at follow-up (r(s) = 0.39, p = 0.0024). Head circumference at follow-up was correlated with GA (r(s) = 0.40, p = 0.0012), neonatal IGF-1 (r(s) = 0.37, p = 0.0031), and early weight (r(s) = 0.27, p = 0.035).

CONCLUSIONS

In very preterm children, early and later postnatal growth is closely related to visual acuity and perception at follow-up. In addition, IGF-1 concentrations and early growth are correlated with head circumference and refraction at follow-up.

Visual and cerebral sequelae of very low birth weight in adolescents

OBJECTIVE

To describe the visual functions and relate them to MRI findings and the intellectual level in adolescents born with very low birth weight (VLBW).

DESIGN

Population-based case-control study.

PATIENTS

59 15-year-old VLBW adolescents and 55 sex and age-matched controls with normal birth weight.

MAIN OUTCOME MEASURES

Objective clinical findings (visual acuity, stereo acuity and cycloplegic refraction) were recorded. Structured history taking was used to identify visual difficulties. The intellectual level was assessed with the Wechsler Intelligence Scale for Children (WISC). All VLBW adolescents underwent MRI of the brain.

RESULTS

Significant differences were found between the VLBW adolescents and controls regarding visual acuity (median -0.11 and -0.2, respectively; p=0.004), stereo acuity (median 60'' and 30'', respectively; p<0.001), prevalence of astigmatism (11/58 and 0/55, respectively; p<0.001) and in full-scale IQ (mean IQ 85 and 97, respectively; p<0.001) and performance IQ (mean 87 and 99, respectively; p=0.002). The structured history also revealed a borderline significant difference between the groups (mean problems 0.46 and 0.15 respectively; p=0.051). 30% (17/57) of the VLBW adolescents had abnormal MRI findings and performed worse in all tests, compared with both the VLBW adolescents without MRI pathology and the normal controls.

CONCLUSION

This study confirms previous observations that VLBW adolescents are at a disadvantage regarding visual outcome compared with those with normal birth weight. In 47%, visual dysfunction was associated with abnormal MRI findings and in 33% with learning disabilities. The adolescents with abnormal MRI findings had more pronounced visual and cognitive dysfunction. The findings indicate a cerebral causative component for the visual dysfunction seen in the present study.

Ophthalmological findings in a sample of Swedish children aged 4-15 years

AIMS

To characterize ophthalmological findings in a sample of Swedish children aged 4-15 years.

METHODS

A prospective cross-sectional comprehensive ophthalmological investigation was performed on a sample of 143 children (67 girls, 76 boys) aged 4-15 years.

RESULTS

Visual acuity (VA) in the better eye >or=1.0 (<or=0.0 logMAR) was found in 79% of subjects. None of the children had VA in the better eye <0.5 (>0.3 logMAR). Amblyopia was found in 0.7% of subjects. A total of 68% of the children had no refractive errors. Hyperopia (>or=2.0 dioptres [D] in spherical equivalent [SE]) was found in 9% and myopia (>or=0.5 D SE) in 6% of children. Astigmatism (>or=0.75 D) was recorded in 22% and anisometropia (>or=1.0 D SE) in 3%. A total of 8% were optically corrected. Strabismus was recorded in 3.5%. Signs of visuoperceptual problems were reported in 3% of the children.

CONCLUSION

This sample of Swedish children may serve as a comparison group regarding ophthalmological findings in children aged 4-15 years.