Early assessment of visual function in full term newborns

Relationship between maternal biological features, environmental factors, and newborn neuromotor development associated with visual fixation abilities

Newborn visual fixation abilities predict future cognitive, perceptive, and motor skills. However, little is known about the factors associated with the newborn visual fixation, which is an indicator of neurocognitive abilities. We analyzed maternal biological and environmental characteristics associated with fine motor skills (visual tracking) in 1 month old infants. Fifty-one infants were tested on visual tracking tasks (Infant Visuomotor Behavior Assessment Scale/ Guide for the Assessment of Visual Ability in Infants) and classified according to visual conducts scores. Differences between groups were compared considering motor development (Alberta Infant Motor Scale) maternal mental health (Edinburgh Postnatal Depression Scale and Hamilton Anxiety Scale); home environment (Affordances in the Home Environment for Development Scale); maternal care (Coding Interactive Behavior); breastmilk composition (total fatty acids, proteins, and cortisol); and maternal metabolic profile (serum hormones and interleukins). Mothers of infants with lower visual fixation scores had higher levels of protein in breastmilk at 3 months. Mothers of infants with better visual conduct scores had higher serum levels of T4 (at 1 month) and prolactin (at 3 months). There were no associations between visual ability and motor development, home environment, or maternal care. Early newborn neuromotor development, especially visual and fine motor skills, is associated with maternal biological characteristics (metabolic factors and breastmilk composition), highlighting the importance of early detection of maternal metabolic changes for the healthy neurodevelopment of newborns.

Sensitivity and specificity of the Neonatal Visual Assessment to predict motor and cognitive outcomes in infants born very preterm

BACKGROUND

Very preterm infants are at increased risk of neurodevelopmental impairments. The Neonatal Visual Assessment (NVA) assesses visual function and outcomes and has been used to assess early neurodevelopmental outcomes. This study aimed to compare NVA results of very preterm and term-born infants and to calculate the sensitivity and specificity of the NVA at term equivalent age (TEA) and three months corrected age (CA) to predict motor and cognitive outcomes at 12 months CA in very preterm infants.

METHODS

This prospective observational cohort study recruited infants born before 31 weeks gestation and a healthy term-born control group. The NVA was assessed at TEA and three months CA, and neurodevelopmental outcomes (Bayley Scales of Infant and Toddler Development, Third Edition; Neurosensory Motor Developmental Assessment; Alberta Infant Motor Scale) were performed at 12 months CA. The sensitivity and specificity of the NVA to predict outcomes were calculated based on a previously published optimality score.

RESULTS

248 preterm (54 % male) and 46 term-born infants (48 % male) were analysed. The mean NVA scores of preterm and term-born infants were significantly different at TEA (preterm 3.1±2.1; term-born 1.2±1.7, p < 0.001). The NVA had moderate sensitivity (59-78 %) and low specificity (25-27 %) at TEA, and low sensitivity (21-28 %) and high specificity (86-87 %) at three months CA for the prediction of preterm infants' outcomes at 12 months CA.

CONCLUSION

The NVA at TEA and three months CA was not a strong predictor of motor and cognitive impairments in this contemporary cohort of very preterm infants.

Early Developmental Intervention and Enriched Environment in CDKL5 Developmental and Epileptic Encephalopathy: A Case Report

Objectives

CDKL5 developmental and epileptic encephalopathy (CDKL5-DEE) is a rare X-linked dominant genetic disorder. Family-centered Early Intervention (EI) programs, which promote axonal plasticity and synaptic reorganization through exposure to an enriched environment, should be integrated into clinical practice. However, there is presently a dearth of dedicated EI protocols for patients with CDKL5-DEE and cerebral visual impairment (CVI).

Methods

We present a girl with a deletion of the CDKL5 gene (MIM*300203). At the age of 2 months, the child presented with severe epilepsy. The neurologic examination was abnormal, and she had severe CVI. At the first assessment, at 5 months old, her Developmental Quotient (DQ) on the Griffiths Mental Developmental Scales III (GMDS-III) was equivalent to 3-month-old skills (95% CI). The child was enrolled in an EI program for 6 months.

Results

At 12 months of age, the DQ score was 91. There has been improvement in the neurovisual functions. The findings from the scales show a gradual improvement in neuromotor and psychomotor development, which is in contrast to the expected outcome of the disease.

Discussion

The case study shows that a family-centered EI and prompt assessment of CVI can promote and enhance neurodevelopment.

Computational methodology to support functional vision assessment in premature infants: A viability study

BACKGROUND

Premature newborns have a higher risk of abnormal visual development and visual impairment.

OBJECTIVE

To develop a computational methodology to help assess functional vision in premature infants by tracking iris distances.

METHODS

This experimental study was carried out with children up to two years old. A pattern of image capture with the visual stimulus was proposed to evaluate visual functions of vertical and horizontal visual tracking, visual field, vestibulo-ocular reflex, and fixation. The participants' visual responses were filmed to compose a dataset and develop a detection algorithm using the OpenCV library allied with FaceMesh for the detection and selection of the face, detection of specific facial points and tracking of the iris positions is done. A feasibility study was also conducted from the videos processed by the software.

RESULTS

Forty-one children of different ages and diagnoses participated in the experimental study, forming a robust dataset. The software resulted in the tracking of iris positions during visual function evaluation stimuli. Furthermore, in the feasibility study, 8 children participated, divided into Pre-term and Term groups. There was no statistical difference in any visual variable analyzed in the comparison between groups.

CONCLUSION

The computational methodology developed was able to track the distances traveled by the iris, and thus can be used to help assess visual function in children.

Visual Function Score: A New Clinical Tool to Assess Visual Function and Detect Visual Disorders in Children

INTRODUCTION

A comprehensive assessment of visual functioning at an early age is important not only for identifying and defining visual impairment but also for planning personalized rehabilitation programs based on the visual diagnosis. Since existing tools to evaluate visual functioning present some important limitations (e.g., they are based on qualitative reports, they do not take into account environmental adaptations of visual testing or they have not been formally validated as clinical instruments), the present work has the main aim to propose a new clinical tool (Visual Function Score, VFS) to detect and define visual disorders at an early age.

METHODS

The Visual Function Score was administered to one hundred visually impaired children (age range 4 months to 17.75 years old) in the form of a professional-reported protocol for a total of 51 items, each of which is assigned a score from 1 to 9 (or from 0 to 9 in some specific cases). The VFS produces three sub-scores and a global score (from 0 to 100), resulting in a quantitative evaluation of visual functioning.

RESULTS

The VFS can detect the well-known differences between different types of visual impairment (cerebral, oculomotor, and peripheral or grouped as central and peripheral) and takes into account different environments in the definition of a quantitative score of visual functioning.

DISCUSSION

Overall, the use of a quantitative tool to evaluate visual functions and functional vision such as the VFS would be fundamental to monitor the progresses of patients over time in response to rehabilitation interventions.

An office-based fix-and-follow grading system assessing visual function in preverbal children

Background

Assessing visual function in infants is usually challenging. Fix-and-Follow is a simple and popular method for assessing early development of visual perception in infants, currently however, there is no formal reproducible method for grading the capacity of fix-and-follow. This study was to develop and validate a new fix-and-follow grading system for assessing visual function development in preverbal children.

Methods

In this cross-sectional study, the fix-and-follow grades was evaluated in 21 consecutive preverbal children. Fixation was categorised as grade 1 if there was no response to the target and grade 2 if there was a response but only for < 3 s. Grades of 3 and 4 were assigned based capacities to (1) fix on a moving target for ≥3 s, and (2) shift fixation from one target to another. If only one of these two criteria was met, grade 3 was assigned. If both were met, grade 4 was assigned. Following was evaluated using smooth pursuit movement, where grade 1 indicated no movement, grade 2 partial movement, and grade 3 complete movement. Two ophthalmologists independently applied the grading method in all patients. Then one of two examiners repeated the examinations to investigate the intra-observer agreement of the grading system.

Results

Intra-observer agreement was excellent (Kappa coefficient = 0.823) and inter-observer agreement was good (Kappa coefficient = 0.625). All patients who exhibited abnormal ocular movement had score discrepancy between a new fix-and-following grading examination.

Conclusions

The new fix-and-follow grading scale can be applied easily in preverbal children in an office setting, and it proved reliable and reproducible.

Cortical Visual Impairment in Childhood: 'Blindsight' and the Sprague Effect Revisited

The paper discusses and provides support for diverse processes of brain plasticity in visual function after damage in infancy and childhood in comparison with injury that occurs in the adult brain. We provide support and description of neuroplastic mechanisms in childhood that do not seemingly exist in the same way in the adult brain. Examples include the ability to foster the development of thalamocortical connectivities that can circumvent the lesion and reach their cortical destination in the occipital cortex as the developing brain is more efficient in building new connections. Supporting this claim is the fact that in those with central visual field defects we can note that the extrastriatal visual connectivities are greater when a lesion occurs earlier in life as opposed to in the neurologically mature adult. The result is a significantly more optimized system of visual and spatial exploration within the ‘blind’ field of view. The discussion is provided within the context of “blindsight” and the “Sprague Effect”.

Home-based early stimulation program targeting visual and motor functions for preterm infants with delayed tracking: Feasibility of a Randomized Clinical Trial

AIMS

To verify the feasibility of a home-based early stimulation program targeting visual and motor functions in preterm infants with delayed visual tracking.

METHOD

We applied a randomized controlled trial. We included thirty low-risk preterm infants, from both genders, with delayed visual tracking, gestational between 28-37 weeks, and age at entrance between 1-2 months of corrected age, and absence of visual impairments. Infants were divided into two groups as follows: a) standard care group (SC) that received general orientation about sensory and motor development (16 infants); b) experimental group, that received a four-week home-based early stimulation program targeting visual and motor functions (ESPVM) applied by the caregivers (14 infants). The feasibility outcomes were retention and loss rates, adherence, adverse events, and stress signals. We obtained preliminary data by comparing visual tracking, motor development, and sensory behavior between groups at the end of the intervention.

RESULTS

Retention rate was high, 90 % of the caregivers provided ESPVM at least 22 days, and 70 % provided SC at least 17 days. No adverse events were reported. At the end of intervention, the ESPVM group presented higher frequencies of complete visual tracking for cards 7 (ESPVM = 57.3 %, SC = 6.3 %, p = 0.006) and 8 (ESPVM = 64.3 %, SC = 12.2 %, p = 0.013), and lower scores for total sensory profile (ESPVM: median = 58, range = 46-69; SC: median = 71, range = 54-90; p = 0.016). The groups were similar for motor development.

CONCLUSIONS

The protocol was feasible, and the results encourage a larger randomized controlled trial.

A study of Ophthalmia Neonatorum in the Central Reion of Ghana: Causative Agents and Antibiotic Susceptibility Patterns

In developing countries such as Ghana, ophthalmia neonatorum (ON) remains a public health concern. This is because of its unknown etiology patterns, the growing concerns of antibiotic resistance strains and the contribution of ON to childhood blindness. This study was therefore conducted to determine the causative agents, risk factors and the antibiotic sensitivity patterns of micro-organisms associated with ON. A clinic-based prospective study was conducted in the Maternal and Child Health units of 6 health care facilities in the Central region of Ghana over a period of 17 months. Conjunctival swabs were taken from all neonates with clinical signs of ON. Isolation and characterization of bacteria were done using standard microbiological methods. Additionally, data were collected and analyzed on neonate's demographics and clinical features of ON. Microbial growth was recorded in 86 cases (52.4%) out of the 110 neonates assessed. Staphylococcus spp. (39.2% of all positive cultures) was the most common causative organism. No case of gonococcus was isolated. Delivery method, vaginal discharge, administration of prophylaxis and weight of neonate were the risk factors associated with the development of ON (P < .05). The level of resistance to Tetracycline was found to be 73%. Neonatal conjunctivitis is more likely to be acquired postnatal. Culture and sensitivity testing are required as an important guide for treatment. The commonest causative organism, Staphylococcus spp., were found to be resistant to Teteracyline, therefore is the need to consider alternatives measures in the prevention and control of ON.

Ocular Motor Paroxysmal Events in Neonates and Infants: A Review of the Literature

BACKGROUND

Ocular paroxysmal events can accompany a variety of neurological disorders. Particularly in infants, ocular paroxysmal events often represent a diagnostic challenge. Distinguishing between epileptic and nonepileptic events or between physiological and pathologic paroxysmal events can be challenging at this age because the clinical evaluation and physical examination are often limited. Continuous polygraphic video-electroencephalography (EEG) monitoring can be helpful in these situations.

METHODS

We review ocular paroxysmal events in newborns and infants. The aim is to improve clinical recognition of ocular paroxysmal events and provide a guide to further management. Using the PubMed database, we identified studies focused on all ocular motor paroxysmal events in neonates and infants.

RESULTS

Fifty-eight articles were selected on the topic. We summarized and divided these studies into those describing nonepileptic and epileptic ocular paroxysmal events.

CONCLUSIONS

The diagnosis of ocular paroxysmal events can be difficult, but their recognition is important because of the variety of underlying etiologies. The distinction between epileptic versus nonepileptic ocular paroxysmal events often often requires polygraphic video-EEG to identify the epileptic events. For nonepileptic events, further testing can characterize pathologic ocular movements. To determine the etiology and prognosis of ocular paroxysmal events, a multimodal approach is required, including a thorough full history and clinical examination, polygraphic video-EEG monitoring, neuroimaging, and a careful follow-up plan.

Effects of Early Intervention on Visual Function in Preterm Infants: A Randomized Controlled Trial

Objectives: To determine the effectiveness of an early intervention program in enhancing visual function in very preterm infants. Methods: We conducted a RCT. We included preterm infants born between 25⁺⁰ and 29⁺⁶ weeks of gestational age (GA), without severe morbidities, and their families. Infants were randomized to either receive Standard Care (SC) or Early Intervention (EI). SC, according to NICU protocols, included Kangaroo Mother Care and minimal handling. EI included, in addition to routine care, parental training according to the PremieStart program, and multisensory stimulation (infant massage and visual interaction) performed by parents. Visual function was assessed at term equivalent age (TEA) using a prevalidated battery evaluating ocular spontaneous motility, ability to fix and follow a target, reaction to color, stripes discrimination and visual attention at distance. Results: Seventy preterm (EI n = 34, SC n = 36) infants were enrolled. Thirteen were excluded according to protocol. Fifty-seven infants (EI = 27, SC = 30) were assessed at TEA. The two groups were comparable for parental and infant characteristics. In total, 59% of infants in the EI group achieved the highest score in all the nine assessed items compared to 17% in the SC group (p = 0.001): all infants in both groups showed complete maturation in four items, but EI infants showed more mature findings in the other five items (ocular motility both spontaneous and with target, tracking arc, stripes discrimination and attention at distance). Conclusions: Our results suggest that EI has a positive effect on visual function maturation in preterm infants at TEA. Trial Registration: clinicalTrial.gov (NCT02983513).

Cerebral Visual Impairment and Clinical Assessment: The European Perspective

This paper summarizes the multidisciplinary pediatric assessment methods of 3 European centers for identifying and assessing cerebral visual impairment in childhood. It describes a comprehensive neurodevelopmental assessment evaluation in which visual aspects play an important part. Developmental trajectories and the heterogeneity of the clinical picture are emphasized. Multidisciplinary ophthalmology and neurodisability/neurology teamwork together with the parent and teachers, to reach an integrated and individualized perspective for the individual child, are described. This comprehensive assessment is the starting point for habilitation programs and interventions, that can support and meet the child's needs and help them reach their optimal potential. Future developments in classification of the cerebral visual impairment conditions, building on the child's individual assessment profile, will further enhance the direction of clinical, educational, and research progress.

Visual configural processing in adults born at extremely low birth weight

Being born at extremely low birth weight (ELBW; ≤1,000 g) is associated with enduring visual impairments. We tested for long-term, higher order visual processing problems in the oldest known prospectively followed cohort of ELBW survivors. Configural processing (spacing among features of an object) was examined in 62 adults born at ELBW (M_age  = 31.9 years) and 82 adults born at normal birth weight (NBW; ≥2,500 g: M_age  = 32.5 years). Pairs of human faces, monkey faces, or houses were presented in a delayed match-to-sample task, where non-matching stimuli differed only in the spacing of their features. Discrimination accuracy for each stimulus type was compared between birth weight groups, adjusting for neurosensory impairment, visual acuity, binocular fusion ability, IQ, and sex. Both groups were better able to discriminate human faces than monkey faces (p < .001). However, the ELBW group discriminated between human faces (p < .001), between monkey faces (p < .001), and to some degree, between houses (p < .06), more poorly than NBW control participants, suggesting a general deficit in perceptual processing. Human face discrimination was related to performance IQ (PIQ) across groups, but especially among ELBW survivors. Coding (a PIQ subtest) also predicted human face discrimination in ELBW survivors, consistent with previously reported links between visuo-perceptive difficulties and regional slowing of cortical activity in individuals born preterm. Correlations with Coding suggested ELBW survivors may have used a feature-matching approach to processing human faces. Future studies could examine brain-based anatomical and functional evidence for altered face processing, as well as the social and memory consequences of face-processing deficits in ELBW survivors.

Perinatal risk factors for visuospatial attention and processing dysfunctions at 1 year of age in children born between 26 and 32 weeks

BACKGROUND

Children born preterm are at risk of visuospatial attention orienting and processing dysfunctions, which can be quantified early in life using visually-guided eye movement responses.

AIMS

To identify the prevalence and perinatal risk factors for visuospatial attention orienting and processing dysfunctions in children born preterm of 1 year of corrected age (CA).

STUDY DESIGN

123 children born between 26 and 33 weeks of gestation underwent a nonverbal visuospatial test at 1y CA, using an eye tracking-based paradigm. For the detected high-salient (cartoon and contrast), intermediate-salient (form and motion) and low-salient (color) stimuli, we quantified the reaction time to fixation (RTF). RTFs were compared to normative references from an age-matched control group (N = 38). The prevalence of perinatal risk factors (gestational age and weight, indices of neurological damage, overal sickness, respiratory failure, and retinopathy) was compared between the groups with normal and delayed RTFs.

RESULTS

At 1y CA, the preterm group had 7-20% less detected stimuli than the control group, particularly for intermediate and low-salient stimuli. Compared to normative RTFs, modest delays were found for high-salient cartoon (in 19% of preterm children) and contrast (8%), intermediate-salient motion (23%) and form (21%), and low-salient color stimuli (8%). These children had a significantly higher prevalence of perinatal risk factors for respiratory failure and intraventricular hemorrhages.

CONCLUSIONS

Children born between 26 and 32 weeks have a modest risk (8-23%) of visuospatial attention and processing dysfunction. This warrants early monitoring and support of general visual development in preterm children at risk of respiratory distress and disrupted cerebral blood flow.

The human newborn's umwelt: Unexplored pathways and perspectives

Historically, newborns, and especially premature newborns, were thought to "feel nothing." However, over the past decades, a growing body of evidence has shown that newborns are aware of their environment, but the extent and the onset of some sensory capacities remain largely unknown. The goal of this review is to update our current knowledge concerning newborns' perceptual world and how ready they are to cope with an entirely different sensory environment following birth. We aim to establish not only how and when each sensory ability arises during the pre-/postbirth period but also discuss how senses are studied. We conclude that although many studies converge to show that newborns are clearly sentient beings, much is still unknown. Further, we identify a series of internal and external factors that could explain discrepancies between studies, and we propose perspectives for future studies. Finally, through examples from animal studies, we illustrate the importance of this detailed knowledge to pursue the enhancement of newborns' daily living conditions. Indeed, this is a prerequisite for assessing the effects of the physical environment and routine procedures on newborns' welfare.

Microcephaly and Zika virus: Neuroradiological aspects, clinical findings and a proposed framework for early evaluation of child development

BACKGROUND AND AIMS

As the recent outbreak of microcephaly cases caused by Zika virus has been declared a global health emergency, providing assessment guidelines for multidisciplinary teams providing early developmental screening and stimulation to infants with microcephaly is much needed. Thus, the aim of this manuscript is to provide an overview on what is known about neuroradiological aspects and clinical findings in infants with microcephaly caused by Zika virus and to propose a framework for early evaluation of child development.

METHODS

The keywords "Zika virus" and "microcephaly" were searched in PubMed database for articles published from incept to May 2017. These texts were reviewed, and the ones addressing neuroradiological and clinical findings in infants were selected. Recommendations for early assessment were made based on the International Classification of Functionality Disability and Health (ICF) model.

OUTCOMES AND RESULTS

The database search yielded 599 publications and 36 were selected. The studies detected microcephaly with diffuse brain malformations and calcifications, ventriculomegaly, optic nerve hypoplasia, macular atrophy, cataracts, impaired visual and hearing function, arthrogryposis, spasticity, hyperreflexia, irritability, tremors, and seizures, but very little is known about early development. Early assessments were described based on the ICF domains (Body Function and Structures, Activities and Participation and Contextual factors).

CONCLUSION AND IMPLICATIONS

Studies published showed abnormal brain, optic, neurologic and orthopedic findings, but very little is known about other aspects of functioning in infants with microcephaly caused by Zika virus. The biopsychosocial model based on the ICF paradigm provides an adequate framework to describe the condition of the infant with microcephaly receiving rehabilitative efforts to minimize disability. Efforts towards early identification of developmental delays should be taken within the first six months of life.

Enhanced visual performance in obsessive compulsive personality disorder

Visual performance is considered as commanding modality in human perception. We tested whether Obsessive-compulsive personality disorder (OCPD) people do differently in visual performance tasks than people without OCPD. One hundred ten students of Ferdowsi University of Mashhad and non-student participants were tested by Structured Clinical Interview for DSM-IV Axis II Personality Disorders (SCID-II), among whom 18 (mean age = 29.55; SD = 5.26; 84% female) met the criteria for OCPD classification; controls were 20 persons (mean age = 27.85; SD = 5.26; female = 84%), who did not met the OCPD criteria. Both groups were tested on a modified Flicker task for two dimensions of visual performance (i.e., visual acuity: detecting the location of change, complexity, and size; and visual contrast sensitivity). The OCPD group had responded more accurately on pairs related to size, complexity, and contrast, but spent more time to detect a change on pairs related to complexity and contrast. The OCPD individuals seem to have more accurate visual performance than non-OCPD controls. The findings support the relationship between personality characteristics and visual performance within the framework of top-down processing model.

Quantification of visual function assessment using remote eye tracking in children: validity and applicability

PURPOSE

Measurements of visual and oculomotor functions are essential for providing tailored support to visually impaired children. In young or intellectually disabled children these measurements can be difficult or even impossible to perform. Recordings of orienting gaze in response to specific visual information, made with eye tracking, may offer a solution. The aim of this study was to observe and quantify eye tracking (ET)-based gaze responses to provide information about visual and oculomotor functioning, and to compare this information with standard visual function assessments (VFA).

METHODS

One hundred and twenty-six visually impaired children from 1-14 years underwent a VFA. Next they underwent a remote ET test. Four aspects of oculomotor control (nystagmus, fixation, saccades, pursuit) and three visual functions (visual field, contrast, colour) were selected to compare both methods. Performance was assessed (1) during VFA using standard behavioural observation and test scores and (2) after ET by observing and scoring the eye movement recordings. Validity, in terms of agreement between results, was measured by correlation analyses. From the orienting gaze responses, quantitative parameters (gain, fixation duration and directional saccades) were calculated to characterize visual performance.

RESULTS

Good agreement between the two test methods was found for observational assessment of oculomotor control and visual functions (correlations ranging from rs  = 0.39 to rs  = 0.69). The quantitative parameters of visual performance showed distinct results between children with and without specific functional impairments, both in children aged 1-6 and 7-14 years.

CONCLUSION

Eye tracking-based gaze recordings are a promising tool to assess oculomotor and visual performance in a communication-free manner. Calculating quantitative parameters from specific gaze responses could assist in the characterization of functional visual performance in children, independent of age. Gaze responses are a useful addition to standard VFA in clinical practice.

A Method to Quantify Visual Information Processing in Children Using Eye Tracking

Visual problems that occur early in life can have major impact on a child's development. Without verbal communication and only based on observational methods, it is difficult to make a quantitative assessment of a child's visual problems. This limits accurate diagnostics in children under the age of 4 years and in children with intellectual disabilities. Here we describe a quantitative method that overcomes these problems. The method uses a remote eye tracker and a four choice preferential looking paradigm to measure eye movement responses to different visual stimuli. The child sits without head support in front of a monitor with integrated infrared cameras. In one of four monitor quadrants a visual stimulus is presented. Each stimulus has a specific visual modality with respect to the background, e.g., form, motion, contrast or color. From the reflexive eye movement responses to these specific visual modalities, output parameters such as reaction times, fixation accuracy and fixation duration are calculated to quantify a child's viewing behavior. With this approach, the quality of visual information processing can be assessed without the use of communication. By comparing results with reference values obtained in typically developing children from 0-12 years, the method provides a characterization of visual information processing in visually impaired children. The quantitative information provided by this method can be advantageous for the field of clinical visual assessment and rehabilitation in multiple ways. The parameter values provide a good basis to: (i) characterize early visual capacities and consequently to enable early interventions; (ii) compare risk groups and follow visual development over time; and (iii), construct an individual visual profile for each child.

Evaluation and Acceptability of a Simplified Test of Visual Function at Birth in a Limited-Resource Setting

Neurological examination, including visual fixation and tracking of a target, is routinely performed in the Shoklo Malaria Research Unit postnatal care units on the Thailand-Myanmar border. We aimed to evaluate a simple visual newborn test developed in Italy and performed by non-specialized personnel working in neonatal care units. An intensive training of local health staff in Thailand was conducted prior to performing assessments at 24, 48 and 72 hours of life in healthy, low-risk term singletons. The 48 and 72 hours results were then compared to values obtained to those from Italy. Parents and staff administering the test reported on acceptability. One hundred and seventy nine newborns, between June 2011 and October 2012, participated in the study. The test was rapidly completed if the infant remained in an optimal behavioral stage (7 ± 2 minutes) but the test duration increased significantly (12 ± 4 minutes, p < 0.001) if its behavior changed. Infants were able to fix a target and to discriminate a colored face at 24 hours of life. Horizontal tracking of a target was achieved by 96% (152/159) of the infants at 48 hours. Circular tracking, stripe discrimination and attention to distance significantly improved between each 24-hour test period. The test was easily performed by non-specialized local staff and well accepted by the parents. Healthy term singletons in this limited-resource setting have a visual response similar to that obtained to gestational age matched newborns in Italy. It is possible to use these results as a reference set of values for the visual assessment in Karen and Burmese infants in the first 72 hours of life. The utility of the 24 hours test should be pursued.

Developmental synergy between thalamic structure and interhemispheric connectivity in the visual system of preterm infants

Thalamic structural co-variation with cortical regions has been demonstrated in preterm infants, but its relationship to cortical function and severity of non-cystic white matter injury (non-cystic WMI) is unclear. The relationship between thalamic morphology and both cortical network synchronization and cortical structural connectivity has not been established. We tested the hypothesis that in preterm neonates, thalamic volume would correlate with primary cortical visual function and microstructural integrity of cortico-cortical visual association pathways. A total of 80 term-equivalent preterm and 44 term-born infants underwent high-resolution structural imaging coupled with visual functional magnetic resonance imaging or diffusion tensor imaging. There was a strong correlation between thalamic volume and primary visual cortical activation in preterms with non-cystic WMI (r = 0.81, p-value = 0.001). Thalamic volume also correlated strongly with interhemispheric cortico-cortical connectivity (splenium) in preterm neonates with a relatively higher severity of non-cystic WMI (p-value < 0.001). In contrast, there was lower correlation between thalamic volume and intrahemispheric cortico-cortical connectivity, including the inferior longitudinal fasciculus and inferior frontal orbital fasciculus. This study shows distinct temporal overlap in the disruption of thalamo-cortical and interhemispheric cortico-cortical connectivity in preterm infants suggesting developmental synergy between thalamic morphology and the emergence of cortical networks in the last trimester.

Safety and efficacy of topiramate in neonates with hypoxic ischemic encephalopathy treated with hypothermia (NeoNATI)

BACKGROUND

Despite progresses in neonatal care, the mortality and the incidence of neuro-motor disability after perinatal asphyxia have failed to show substantial improvements. In countries with a high level of perinatal care, the incidence of asphyxia responsible for moderate or severe encephalopathy is still 2-3 per 1000 term newborns. Recent trials have demonstrated that moderate hypothermia, started within 6 hours after birth and protracted for 72 hours, can significantly improve survival and reduce neurologic impairment in neonates with hypoxic-ischemic encephalopathy. It is not currently known whether neuroprotective drugs can further improve the beneficial effects of hypothermia. Topiramate has been proven to reduce brain injury in animal models of neonatal hypoxic ischemic encephalopathy. However, the association of mild hypothermia and topiramate treatment has never been studied in human newborns. The objective of this research project is to evaluate, through a multicenter randomized controlled trial, whether the efficacy of moderate hypothermia can be increased by concomitant topiramate treatment.

METHODS/DESIGN

Term newborns (gestational age ≥ 36 weeks and birth weight ≥ 1800 g) with precocious metabolic, clinical and electroencephalographic (EEG) signs of hypoxic-ischemic encephalopathy will be randomized, according to their EEG pattern, to receive topiramate added to standard treatment with moderate hypothermia or standard treatment alone. Topiramate will be administered at 10 mg/kg once a day for the first 3 days of life. Topiramate concentrations will be measured on serial dried blood spots. 64 participants will be recruited in the study. To evaluate the safety of topiramate administration, cardiac and respiratory parameters will be continuously monitored. Blood samplings will be performed to check renal, liver and metabolic balance. To evaluate the efficacy of topiramate, the neurologic outcome of enrolled newborns will be evaluated by serial neurologic and neuroradiologic examinations. Visual function will be evaluated by means of behavioural standardized tests.

DISCUSSION

This pilot study will explore the possible therapeutic role of topiramate in combination with moderate hypothermia. Any favourable results of this research might open new perspectives about the reduction of cerebral damage in asphyxiated newborns.

Visual performance in preterm infants with brain injuries compared with low-risk preterm infants

BACKGROUND

Neonatal brain injuries are the main cause of visual deficit produced by damage to posterior visual pathways. While there are several studies of visual function in low-risk preterm infants or older children with brain injuries, research in children of early age is lacking.

AIM

To assess several aspects of visual function in preterm infants with brain injuries and to compare them with another group of low-risk preterm infants of the same age.

STUDY DESIGN AND SUBJECTS

Forty-eight preterm infants with brain injuries and 56 low-risk preterm infants.

OUTCOME MEASURES

The ML Leonhardt Battery of Optotypes was used to assess visual functions. This test was previously validated at a post-menstrual age of 40 weeks in newborns and at 30-plus weeks in preterm infants.

RESULTS

The group of preterm infants with brain lesions showed a delayed pattern of visual functions in alertness, fixation, visual attention and tracking behavior compared to infants in the healthy preterm group. The differences between both groups, in the visual behaviors analyzed were around 30%. These visual functions could be identified from the first weeks of life.

CONCLUSION

Our results confirm the importance of using a straightforward screening test with preterm infants in order to assess altered visual function, especially in infants with brain injuries. The findings also highlight the need to provide visual stimulation very early on in life.

Visual function assessment in late-preterm newborns

AIM

To describe the development of visual functions in a population of low-risk late preterm infants.

SUBJECTS AND METHODS

Eighty low-risk late preterm with a gestational age between 34.0 and 36.9 weeks were assessed at birth and at term equivalent age (TEA) using a structured visual assessment battery. The results were compared to those previously obtained in term born infants using the same battery.

RESULTS

For 5 items (spontaneous ocular motility, ocular motility with target, fixation, horizontal tracking and color tracking) the results were similar both at birth and TEA; for the other 4 (vertical and arc tracking, ability to discriminate striped black/white targets and attention at distance) visual findings at TEA were more mature than at birth. Comparing the responses in late preterm at TEA and term-born infants at 48 h of life, only 2 items (attention at distance, ability to discriminate black/white stripes) were different, with more mature findings in late preterm infants.

CONCLUSIONS

Our results show that in late preterm some aspects of visual functions have a progressive maturation infants between birth and TEA, confirming that the time between birth and term age appears to be crucial for the development of these abilities.

Study protocol: safety and efficacy of propranolol in newborns with Retinopathy of Prematurity (PROP-ROP): ISRCTN18523491

Background

Despite new therapeutic approaches have improved the prognosis of newborns with retinopathy of prematurity (ROP), an unfavourable structural and functional outcome still remains high. There is high pressure to develop new drugs to prevent and treat ROP. There is increasing enthusiasm for anti-VEGF drugs, but angiogenic inhibitors selective for abnormal blood vessels would be considered as an optimal treatment.

In an animal experimental model of proliferative retinopathy, we have recently demonstrated that the pharmacological blockade of beta-adrenoreceptors improves retinal neovascularization and blood retinal barrier breakdown consequent to hypoxia. The purpose of this study is to evaluate the propranolol administration in preterm newborns suffering from a precocious phase of ROP in terms of safety and efficacy in counteracting the progression of retinopathy.

Methods/Design

Preterm newborns (gestational age at birth lower than 32 weeks) with stage 2 ROP (zone II-III without plus) will be randomized, according to their gestational age, to receive propranolol added to standard treatment (treatment adopted by the ETROP Cooperative Group) or standard treatment alone. Propranolol will be administered until retinal vascularization will be completely developed, but not more than 90 days. Forty-four participants will be recruited into the study. To evaluate the safety of propranolol administration, cardiac and respiratory parameters will be continuously monitored. Blood samplings will be performed to check renal, liver and metabolic balance. To evaluate the efficacy of propranolol, the progression of the disease, the number of laser treatments or vitrectomies, the incidence of retinal detachment or blindness, will be evaluated by serial ophthalmologic examinations. Visual function will be evaluated by means of behavioural standardized tests.

Discussion

This pilot study is the first research that explores the possible therapeutic role of beta blockers in ROP. The objective of this research is highly ambitious: to find a treatment simple, inexpensive, well tolerated and with few adverse effects, able to counteract one of the major complications of the prematurity. Any favourable results of this research could open new perspectives and original scenarios about the treatment or the prevention of this and other proliferative retinopathies.

Trial Registration

Current Controlled Trials ISRCTN18523491; ClinicalTrials.gov Identifier NCT01079715; EudraCT Number 2010-018737-21

Plasticity of the visual system after early brain damage

The aim of this review is to discuss the existing evidence supporting different processes of visual brain plasticity after early damage, as opposed to damage that occurs during adulthood. There is initial evidence that some of the neuroplastic mechanisms adopted by the brain after early damage to the visual system are unavailable at a later stage. These are, for example, the ability to differentiate functional tissue within a larger dysplastic cortex during its formation, or to develop new thalamo-cortical connections able to bypass the lesion and reach their cortical destination in the occipital cortex. The young brain also uses the same mechanisms available at later stages of development but in a more efficient way. For example, in people with visual field defects of central origin, the anatomical expansion of the extrastriatal visual network is greater after an early lesion than after a later one, which results in more efficient mechanisms of visual exploration of the blind field. A similar mechanism is likely to support some of the differences found in people with blindsight, the phenomenon of unconscious visual perception in the blind field. In particular, compared with people with late lesions, those with early brain damage appear to have stronger subjective awareness of stimuli hitting the blind visual field, reported as a conscious feeling that something is present in the visual field. Expanding our knowledge of these mechanisms could help the development of early therapeutic interventions aimed at supporting and enhancing visual reorganization at a time of greatest potential brain plasticity.

Visual performance and brain structures in the developing brain of pre-term infants

The presence of abnormal visual function has been related to overt lesions in the thalami, peritrigonal white matter (such as cavitational-necrotic periventricular leucomalacia) and optic radiations, and also to the extent of occipital cortex involvement. The normal development of visual function seems to depend on the integrity of a network that includes not only optic radiations and the primary visual cortex but also other cortical and subcortical areas, such as the frontal or temporal lobes or basal ganglia, which have been found to play a topical role in the development of vision. Therefore, the complex functions and functional connectivity of the developing brain of premature infants can be studied only with highly sophisticated techniques such as diffusion tensor tractography. The combined use of visual tests and neonatal structural and functional neuroimaging, which have become available for newborn infants, provides a better understanding of the correlation between structure and function from early life. This appears to be particularly relevant considering the essential role of early visual function in cognitive development. The identification of early visual impairment is also important, as it allows for early enrolment in intervention programmes. The association of clinical and functional studies to newer imaging techniques, which are being increasingly used also in neonates, are likely to provide further information on early aspects of vision and the mechanisms underlying brain plasticity, which are still not fully understood. Early exposure to a difficult postnatal environment together with early and unexpected removal from a protective milieu are exclusive and peculiar factors of prematurity that interfere with the normal development of the visual system in pre-term babies. The problem is further compounded by the influence of different perinatal brain lesions affecting the developing brain of premature babies. Nevertheless, in the last few decades, there have been considerable advances in our understanding of the development of vision in pre-term infants during early infancy. This has mainly been due to the development of age-specific tests assessing various aspects of visual function, from ophthalmological examination to more cortical aspects of vision, such as the ability to process orientation or different aspects of visual attention [1-7]. Improvements in understanding very early and specific neurological impairments in neurological functions have been reported in pre-term infants, known to be at risk of developing visual and visual-perceptual impairment. These impairments are due not only to retinopathy, a common finding in premature infants, but also to cerebral (central) visual impairment, secondary to brain lesions affecting the central visual pathway.

Visual function at 35 and 40 weeks' postmenstrual age in low-risk preterm infants

OBJECTIVES

The objectives of this study were to (1) assess visual function in low-risk preterm infants at 35 and 40 weeks' postmenstrual age, (2) compare preterm visual abilities at term-equivalent age with term-born infants, and (3) evaluate effects of preterm extrauterine life on early visual function.

METHODS

Visual function was assessed by using a validated test battery at 35 and 40 weeks' postmenstrual age in 109 low-risk preterm infants who were born at <31 weeks' gestation. The preterm findings were compared with data from term-born infants collected by using the same test protocol.

RESULTS

All preterm infants completed both assessments. The 35-week responses were generally less mature than those at 40 weeks. Preterm infants at both ages were significantly more mature than term-born infants for ocular movements and vertical and arc tracking and at 40 weeks for stripe discrimination. In contrast, tracking a colored stimulus, attention at distance, and stripe discrimination were more mature at term age (in both term-born and preterm infants) than at 35 weeks.

CONCLUSIONS

Our findings provide data for visual function at 35 and 40 weeks' postmenstrual age in low-risk preterm infants. The results suggest that early extrauterine experience may accelerate the maturation of aspects of visual function related to ocular stability and tracking but does not seem to affect other aspects that may be more cortically mediated.