Visual development in infants: physiological and pathological mechanisms

Postoperative amblyopia in children with congenital cataracts: a systematic review and meta-analysis

This systematic review and meta-analysis aimed to estimate the prevalence of amblyopia following congenital cataract surgery in children and evaluate key prognostic factors, including age at intervention, cataract phenotype, and follow-up duration. We systematically searched PubMed, EMBASE, and the Cochrane Library for studies published between January 1, 1981, and March 1, 2023. We included clinical trials, case series, and observational studies to analyze surgical timing, visual outcomes, and complications. Among 28 studies (2,167 patients, 3,371 eyes), the pooled amblyopia prevalence was 62% (95% CI: 0.55-0.69, I2 = 91.7%). Early surgery (≤ 8 weeks for unilateral, ≤ 12 weeks for bilateral cases) significantly reduced amblyopia risk (P < 0.001) but increased complications, notably glaucoma (26% vs. 6%, P = 0.001). In contrast, intraocular lens (IOL) implantation timing had no significant effect on visual outcomes (P = 0.096). Unilateral partial obstruction conferred a higher amblyopia prevalence than bilateral complete obstruction (68% vs. 36%, P = 0.003), and prolong amblyopia therapy beyond 6 years of age showed limited efficacy. These findings highlight the critical role of timely surgery in optimizing visual recovery, despite its association with complications. Early IOL implantation demonstrated no significant clinical benefits, and the therapeutic window for amblyopia rehabilitation in congenital cataracts is narrower than in other forms.

Compliance with rigid gas-permeable contact lens use in children younger than 6 years in China: a 6-year retrospective study

PURPOSE

To explore the abandonment rate and factors influencing the use of rigid gas-permeable contact lenses (RGPCL) among children aged < 6 years.

METHODS

This retrospective case series study included 70 children aged < 6 years who were fitted with RGPCL for visual rehabilitation between January 2016 and December 2021. We collected data on indications, discontinuation rates, and reasons for discontinuation from medical records and via telephone calls and investigated the factors influencing contact lens abandonment.

RESULTS

The median age of the 70 participants was 5.0 (interquartile range: 4.0-5.9) years. Further, 36 (51.4%) children stopped wearing contact lenses; among them, 17 (47.2%) stopped within 3 months, and the median duration of lens wearing was 4.0 (interquartile range: 1.0-11.5) months. Additionally, there was a correlation between the duration of lens wearing and lens abandonment (r = -0.698, P < 0.001). A high parental education level (hazard ratio [HR] = 0.425; 95% confidence interval [CI] 0.198, 0.913; P = 0.028) was a protective factor against lens abandonment, while parental assessment indicating harder than expected practicality (HR = 4.062; 95% CI 1.204, 13.707; P = 0.024) was a risk factor for abandonment.

CONCLUSION

Children aged < 6 years are susceptible to early discontinuation of RGPCL use. Since parents perform daily lens manipulation, they are crucial to the continuity of lens use in these children. To improve RGPCL use continuity, communication and supervision should be strengthened before and after RGPCL fittings.

Risk of long-term ophthalmological complications in Taiwanese preterm infants: a nationwide cohort study

OBJECTIVES

The aim was to determine whether different maturity levels and birth weights could change the risk of long-term ophthalmological complications in preterm infants.

DESIGN

This was a cohort study.

SETTING

This was a nationwide population-based study.

PARTICIPANTS

Newborns born between 2009 and 2012 were identified; newborns with congenital deformities, newborns with missing data on urban area, sex, gestational week at birth or birth weight and newborns who died before the age of 8 years were excluded.

INTERVENTIONS

Infants were divided into full-term, preterm and preterm with retinopathy of prematurity (ROP) cohorts based on their basic characteristics at birth.

PRIMARY OUTCOME MEASURES

The primary outcomes were ophthalmological complications, including strabismus, refractive error, amblyopia, cataracts and glaucoma.

RESULTS

Ultimately, 735 702 infants were included in the analysis. There were 727 403, 7165 and 1134 newborns in the full term, preterm without ROP and preterm with ROP cohorts, respectively. Premature infants, whether without ROP or with ROP, had an elevated risk of various ophthalmic complications, with adjusted ORs (aORs) ranging from 1.48 to 2.74 and 1.90 to 10.34, respectively. Extremely low birth weight contributes to an increased risk of various ophthalmic complications, with aORs ranging from 2.21 to 6.55. Moreover, a higher number of negative variables, such as preterm birth or low body weight, increased the risk of various ophthalmological complications, with the aOR falling within the range of 1.03-23.86.

CONCLUSIONS

Immaturity and low body weight were risk factors for ophthalmological complications in preterm infants. The presence of both of these two risk factors increased the risk of ophthalmological complications. Our results are essential for caregivers and health policy-makers to design comprehensive follow-up plans for preterm infants.

Visual Acuity Thresholds in Preterm Newborns: An Experimental Study

Purpose: Visual acuity plays a role in mediating neurological development in infants by enabling the differentiation of shapes and discriminating objects. Given the rapid structural development of the brain in the first days of life, this aspect is particularly significant for preterm infants, who typically experience this developmental phase while hospitalized in the neonatal intensive care unit (NICU). Therefore, this study aimed to assess visual acuity thresholds in preterm infants during hospitalization and to evaluate possible correlations between visual acuity and clinical parameters. Methods: A cross-sectional study was conducted in an NICU in Northeast Brazil. The visual acuity thresholds were tested using the Teller Acuity Cards II, comprised of 17 gray cards, with one 4 mm diameter peephole at the center and presented with about 35% reflectance. Preterm infants were positioned supine, at 30° elevation on the laps of their caregivers. The evaluator presented both sides of the cards and observed the eye fixation and reactions on both sides. Results: A total of 42 preterm infants with corrected gestational age between 30 to 36 weeks and 6 days were included. Visual acuity ranged from 0.23 to 0.64 cycle per degree. The mean visual acuity threshold was 0.32 cycles per degree for preterm infants at around 32 weeks of corrected gestational age. The visual acuity was not correlated with gestational age (p = 0.18), and neither were birth weight (p = 0.83) or duration of respiratory support (p = 0.98). However, days of phototherapy were inversely correlated with visual acuity (p = 0.04). Conclusions: Despite the challenges of hospitalization, it was possible to carry out a psychophysical test to assess visual acuity in preterm infants. The visual acuity showed no correlation with clinical parameters such as gestational age, birth weight, and duration of respiratory support. However, there was an inverse correlation between the number of days in phototherapy and visual acuity. Understanding the visual acuity levels in preterm infants during their NICU stay can contribute to tailoring interventions and care strategies that specifically address their visual developmental needs. This knowledge may guide healthcare professionals in optimizing the NICU environment to provide appropriate visual stimuli that support neurological development.

Effects of environmental enrichment on GLUT expression in the visual cortex of amblyopic rats

OBJECTIVE

To investigate the potential changes of glucose metabolism and glucose transporter protein (GLUT) in the visual cortex of formally deprived amblyopic rats, as well as the effects of enriched environments on the levels of nerve conduction and glucose metabolism in the visual cortex of amblyopic rats.

METHODS

36 rats were randomly divided into three groups: CON + SE (n = 12), MD + SE (n = 12) and MD + EE (n = 12). The right eyelids of both MD + SE and MD + EE groups were sutured. After successful modelling, the MD + EE group was maintained in an enriched environment, and the other two groups were kept in the same environment. Pattern visual evoked potentials (PVEP) was used to confirm models' effect, glucose metabolism was analyzed by Micro-PET/CT (18F-FDG), and the protein as well as mRNA expression levels of GLUT were detected by Western Blot and quantitative RT-PCR (quantitative Reverse Transcription-Polymerase Chain Reaction) analyses, site of GLUT expression by immunofluorescence (IF).

RESULTS

After suture modelling, both the MD + EE and MD + SE groups objective visual nerve conduction function decreased, the glucose metabolism in the visual cortex was markedly lower. After the enriched environment intervention, it recovered in the MD + EE group. The expression levels of GLUT1 and GLUT3 were increased in the MD + EE group in comparison with the MD + SE group. GLUT1 was primarily expressed on astrocytes and endothelial cells, but GLUT3 was mainly expressed on neurons.

CONCLUSION

Enrichment of the environment exhibited a therapeutic effect on amblyopia, which could be related to the enhancement of glucose metabolism and GLUT expression in the visual cortex.

The Impact of Cerebral Visual Impairment on Social Skills and Sensory Processing

Limited evidence exists on the impact of cerebral visual impairment (CVI) on developmental domains in toddlers. This study investigated whether CVI influences social skills and sensory processing in toddlers with cerebral palsy (CP). The study included toddlers with CP, with or without CVI, and typically developing (TD) toddlers. All parents completed the demographic information form. Social skills were assessed by the Brief Infant-Toddler Social and Emotional Assessment (BITSEA). Sensory processing was evaluated by the Infant/Toddler Sensory Profile (ITSP). Analysis of covariance was employed to assess the disparity in BITSEA and ITSP scores. Toddlers with CP and CVI group demonstrated lower social competence than the other groups (p < .05). Having CVI did not cause a statistically significant difference in sensory processing among toddlers with CP (p > .05). CVI significantly affects social competence in toddlers with CP but does not affect sensory processing.

The Freiburg Acuity Test in Preschool Children: Testability, Test-Retest Variability, and Comparison With LEA Symbols

Purpose

To determine the testability, performance, and test-retest variability (TRV) of visual acuity (VA) assessment using the Freiburg Visual Acuity Test (FrACT) compared to the LEA Symbols Test (LEA) in preschool children.

Methods

In 134 preschool children aged 3.0 to 6.8 years, monocular VA of each eye was measured twice with a four-orientation Landolt C version of the FrACT and once with the LEA. FrACT runs were preceded by a binocular run for explanatory purposes. Test order alternated between subjects. Optotypes were presented on a computer monitor (FrACT) or on cards (LEA) at a distance of 3 m.

Results

Overall, 68% completed the FrACT (91/134 children) and 88% completed the LEA (118/134 children). Testability depended on age: FrACT, 19% (<4 years) and 87% (≥4 years); LEA, 70% (<4 years) and 95% (≥4 years). Mean ± SD VA difference between tests was 0.11 ± 0.19 logarithm of the minimum angle of resolution [logMAR], with LEA reporting better acuity. The difference depended on age (0.27 ± 0.23 logMAR [<4 years], 0.09 ± 0.18 logMAR [≥4 years], P < 0.001) and on test sequence (higher age dependence of FrACT VAs for LEA first, P < 0.001). The 95% limits of agreement for the FrACT TRV were ±0.298 logMAR.

Conclusions

The examiner-independent FrACT, using international reference Landolt C optotypes, can be used to assess VA in preschool children aged ≥4 years, with reliability comparable to other pediatric VA tests.

Translational Relevance

Use of the automated FrACT for VA assessment in preschool children may benefit objectivity and validity as it is a computerized test and employs the international reference Landolt C optotype.

Maximizing valid eye-tracking data in human and macaque infants by optimizing calibration and adjusting areas of interest

Remote eye tracking with automated corneal reflection provides insights into the emergence and development of cognitive, social, and emotional functions in human infants and non-human primates. However, because most eye-tracking systems were designed for use in human adults, the accuracy of eye-tracking data collected in other populations is unclear, as are potential approaches to minimize measurement error. For instance, data quality may differ across species or ages, which are necessary considerations for comparative and developmental studies. Here we examined how the calibration method and adjustments to areas of interest (AOIs) of the Tobii TX300 changed the mapping of fixations to AOIs in a cross-species longitudinal study. We tested humans (N = 119) at 2, 4, 6, 8, and 14 months of age and macaques (Macaca mulatta; N = 21) at 2 weeks, 3 weeks, and 6 months of age. In all groups, we found improvement in the proportion of AOI hits detected as the number of successful calibration points increased, suggesting calibration approaches with more points may be advantageous. Spatially enlarging and temporally prolonging AOIs increased the number of fixation-AOI mappings, suggesting improvements in capturing infants' gaze behaviors; however, these benefits varied across age groups and species, suggesting different parameters may be ideal, depending on the population studied. In sum, to maximize usable sessions and minimize measurement error, eye-tracking data collection and extraction approaches may need adjustments for the age groups and species studied. Doing so may make it easier to standardize and replicate eye-tracking research findings.

Compensatory Interactions between Corneal and Internal Astigmatism despite Lifestyle Changes

This study explores whether children's refractive errors and visual behaviors reverted to pre-COVID-19 levels a year after normal schooling resumed in Hong Kong as well as the impact of corneal and internal astigmatism on refractive astigmatism development. Vision survey data and questionnaire results collected in 2022 (n = 119) and 2020 (n = 173) were compared. Cross-sectional data showed similar proportions of astigmatism (cylindrical power ≥ 0.75 D) in the 2020 (49.1%) and 2022 cohorts (55.5%). Despite a 0.28 D increase in corneal astigmatism, a compensatory 0.24 D increase in internal astigmatism of opposite direction kept refractive astigmatism relatively stable. The questionnaire data showed that children spent an additional 0.5 h/day outdoors on weekends post-resumption of normal schooling but engaged in more near-work activities, especially non-screen near-work, by approximately 1 h/day on both weekdays and weekends. These findings were supported by longitudinal data from 72 children who participated in both surveys. This study highlights the significant role of corneal and internal astigmatism in refractive astigmatism changes. Despite the return to in-person classes, children's total near-work time increased and astigmatism remained high. These findings underscore the need for comprehensive strategies to reduce the high environmental risks for refractive error development in children.

Prenatal fluoride exposure, offspring visual acuity and autonomic nervous system function in 6-month-old infants

BACKGROUND

Prenatal fluoride exposure can have adverse effects on children's development; however, associations with visual and cardiac autonomic nervous system functioning are unknown. We examined associations between prenatal fluoride exposure and visual acuity and heart rate variability (HRV) in 6-month-old infants.

METHODS

We used data from Canadian mother-infant pairs participating in the Maternal-Infant Research on Environmental Chemicals (MIREC) cohort. We estimated prenatal fluoride exposure using: i) fluoride concentration in drinking water (mg/L), ii) maternal urinary fluoride adjusted for specific gravity (MUFSG; mg/L) and averaged across pregnancy, and iii) maternal fluoride intake (µg/kg/day) from consumption of water, tea, and coffee, adjusted for maternal body weight (kg). We used multivariable linear regression to examine associations between each measure of fluoride exposure and Teller Acuity Card visual acuity scores (n = 435) and assessed HRV (n = 400) using two measures: root mean square of successive differences (RMSSD) and the standard deviation of N-N intervals (SDNN) measured at 6-months of age.

RESULTS

Median (IQR) values for water fluoride, MUFSG, and daily fluoride intake were 0.20 (IQR: 0.13-0.56) mg/L; 0.44 (0.28-0.70) mg/L and 4.82 (2.58-10.83) µg/kg/day, respectively. After adjustment for confounding variables, water fluoride concentration was associated with poorer infant visual acuity (B = -1.51; 95 % CI: -2.14,-0.88) and HRV as indicated by lower RMSSD (B = -1.60; 95 % CI: -2.74,-0.46) but not SDNN. Maternal fluoride intake was also associated with poorer visual acuity (B = -0.82; 95 % CI: -1.35,-0.29) and lower RMSSD (B = -1.22; 95 % CI: -2.15,-0.30). No significant associations were observed between MUFSG and visual acuity or HRV.

CONCLUSION

Fluoride in drinking water was associated with reduced visual acuity and alterations in cardiac autonomic function in infancy, adding to the growing body of evidence suggesting fluoride's developmental neurotoxicity.

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.

Differential effects of generalized anxiety and separation anxiety on brain structural development during adolescence

Excessive anxiety is highly prevalent during childhood and adolescence, with detrimental effects on somatic and mental health, and quality of life. Although structural abnormalities in the brain have been found in people with anxiety disorders, whether anxiety affects the brain development of children and adolescents remains unknown. Here, we applied a multivariate approach to two single-site MRI datasets consisting of 733 and 775 participants aged 5-18 years. Using linear support vector regression and cross-validation, brain age is estimated by predicting the chronological age from the features that combine cortical thickness and surface area of 68 brain regions. We found that gray matter can predict the chronological age of children and adolescents with a low mean absolute error. Compared to specific brain network, the whole structural brain measures predicted brain age better. Importantly, adolescents with higher generalized anxiety and those with lower separation anxiety showed lower brain age, indicating a slow development of brain structures. The relationship between anxiety and brain age of youths could also be found in parent-reported separation anxiety. The findings highlight differential effects of different anxiety types on brain structural development and suggest that different types of anxiety during childhood and adolescence should be treated differently.

Association between prenatal exposure to trace elements mixture and visual acuity in infants: A prospective birth cohort study

BACKGROUND

Prenatal environmental factors may affect the development of the offspring and can bring long lasting consequences to the offspring's health. To date, only few studies have reported inconclusive association between prenatal single trace element exposure and visual acuity, and no studies have investigated the association between prenatal exposure to trace elements mixture and visual acuity in infants.

METHODS

In the prospective cohort study, grating acuity in infants (12 ± 1 months) was measured by Teller Acuity Cards II. Concentrations of 20 trace elements in maternal urine samples collected in early-trimester were measured by Inductively Coupled Plasma Mass Spectrometry. Elastic net regression (ENET) was applied to select important trace elements. Nonlinear associations of the trace elements levels with abnormal grating were explored using the restricted cubic spline (RCS) method. The associations between selected individual elements and abnormal grating acuity were further appraised using the logistic regression model. Then Bayesian Kernel Machine Regression (BKMR) was used to estimate the joint effects of mixture and interactions between trace elements combining with NLinteraction.

RESULTS

Of 932 mother-infant pairs, 70 infants had abnormal grating acuity. The ENET model produced 8 trace elements with non-zero coefficients, including cadmium, manganese, molybdenum, nickel, rubidium, antimony, tin and titanium. RCS analyses identified no nonlinear associations of the 8 elements with abnormal grating acuity. The single-exposure analyses using logistic regression revealed that prenatal molybdenum exposure possessed a significantly positive association with abnormal grating acuity (odds ratio [OR]: 1.44 per IQR increase, 95% confidence interval [CI]: 1.05, 1.96; P = 0.023), while prenatal nickel exposure presented with a significantly inverse association with abnormal grating acuity (OR: 0.64 per IQR increase, 95% CI: 0.45, 0.89; P = 0.009). Similar effects were also observed in BKMR models. Moreover, the BKMR models and NLinteraction method identified potential interaction between molybdenum and nickel.

CONCLUSIONS

We established that prenatal exposure to high concentration of molybdenum and low concentration of nickel was associated with the increased risk of abnormal visual acuity. Potential interaction may exist between molybdenum and nickel on abnormal visual acuity.

Development of neonatal brain functional centrality and alterations associated with preterm birth

Formation of the functional connectome in early life underpins future learning and behavior. However, our understanding of how the functional organization of brain regions into interconnected hubs (centrality) matures in the early postnatal period is limited, especially in response to factors associated with adverse neurodevelopmental outcomes such as preterm birth. We characterized voxel-wise functional centrality (weighted degree) in 366 neonates from the Developing Human Connectome Project. We tested the hypothesis that functional centrality matures with age at scan in term-born babies and is disrupted by preterm birth. Finally, we asked whether neonatal functional centrality predicts general neurodevelopmental outcomes at 18 months. We report an age-related increase in functional centrality predominantly within visual regions and a decrease within the motor and auditory regions in term-born infants. Preterm-born infants scanned at term equivalent age had higher functional centrality predominantly within visual regions and lower measures in motor regions. Functional centrality was not related to outcome at 18 months old. Thus, preterm birth appears to affect functional centrality in regions undergoing substantial development during the perinatal period. Our work raises the question of whether these alterations are adaptive or disruptive and whether they predict neurodevelopmental characteristics that are more subtle or emerge later in life.

Early detection of visual impairment in young children using a smartphone-based deep learning system

Early detection of visual impairment is crucial but is frequently missed in young children, who are capable of only limited cooperation with standard vision tests. Although certain features of visually impaired children, such as facial appearance and ocular movements, can assist ophthalmic practice, applying these features to real-world screening remains challenging. Here, we present a mobile health (mHealth) system, the smartphone-based Apollo Infant Sight (AIS), which identifies visually impaired children with any of 16 ophthalmic disorders by recording and analyzing their gazing behaviors and facial features under visual stimuli. Videos from 3,652 children (≤48 months in age; 54.5% boys) were prospectively collected to develop and validate this system. For detecting visual impairment, AIS achieved an area under the receiver operating curve (AUC) of 0.940 in an internal validation set and an AUC of 0.843 in an external validation set collected in multiple ophthalmology clinics across China. In a further test of AIS for at-home implementation by untrained parents or caregivers using their smartphones, the system was able to adapt to different testing conditions and achieved an AUC of 0.859. This mHealth system has the potential to be used by healthcare professionals, parents and caregivers for identifying young children with visual impairment across a wide range of ophthalmic disorders.

Association of Neighborhood Child Opportunity Index with presenting visual acuity in amblyopic children

PURPOSE

To demonstrate the use of a novel measure of neighborhood quality, the Child Opportunity Index (COI), for investigating health disparities in pediatric ophthalmology.

METHODS

This study included children 2-12 years of age from a registry of patients diagnosed with amblyopia at an urban pediatric hospital between 2010 and 2014. Children previously treated for amblyopia were excluded. Patient demographics, residential addresses, and logMAR visual acuities were collected. The association between visual acuity at presentation and COI was examined using linear mixed-effects models adjusting for individual-level factors, including age, sex, race, ethnicity, and insurance type.

RESULTS

This study included 1,050 amblyopic children, of whom 317 (37%) were non-White and 149 (19%) were Hispanic; 461 (44%) had public insurance. Regarding residence, 129 (12%) lived in areas of very low opportunity (COI <20); 489 (47%) in areas of very high opportunity (COI ≥80). Children residing in the lowest opportunity neighborhoods correctly identified approximately two fewer letters at presentation with their better-seeing eye compared with children from the highest opportunity neighborhoods after adjusting for individual-level factors (-0.0090 logMAR per 20 unit increase in COI; 95% CI, -0.0172 to -0.0008; P = 0.031). No difference was appreciated in the worse-seeing eye.

CONCLUSIONS

Amblyopic children residing in communities with low neighborhood opportunity had slightly worse visual acuity in the better-seeing eye at presentation. Although statistically significant in the better-seeing eye, the two-letter difference attributable to neighborhood environment may not be clinically significant, and the impact of this disparity on treatment outcomes deserves further investigation.

Parents' intentions toward preschool children's myopia preventive behaviors: Combining the health belief model and the theory of planned behavior

Objective

This study aimed to develop an integrated model based on the health belief model (HBM) and the theory of planned behavior (TPB) to explore the influencing factors of parents' intentions toward preschool children's myopia preventive behaviors.

Methods

This cross-sectional study was conducted in Minhang District, Shanghai, China in January 2022. One thousand six hundred and twenty-eight parents of preschool children from seven preschools were recruited in the study. A four-part questionnaire was used to collect data on socio-demographic characteristics, HBM variables, TPB variables and parental intentions. This study used exploratory factor analysis to analyze HBM and TPB items. Hierarchical multiple regression analysis was performed to explore the relationship between independent variables and parents' intentions toward preschool children's myopia preventive behaviors.

Results

The final integrative model showed that perceived severity, perceived barriers, attitudes, subjective norms, and perceived behavioral control were associated with parents' intentions toward preschool children's myopia preventive behaviors. In model 1, Child's age was entered as a control variable and explained 0.6% of the variance (F = 7.241, p = 0.007). When the HBM variables were entered in model 2, the proportion of variance increased to 25.4% (F = 73.290, P < 0.001). In model 3, TPB variables were entered and explained 63.2% of the variance (F = 246.076, p < 0.001).

Conclusion

The integrated model of HBM and TPB constructed in this study significantly improved the degree of explanation of parents' intentions toward preschool children's myopia preventive behaviors. Parents' perceived severity, perceived barriers, attitudes, subjective norms, and perceived behavioral control can be prioritized intervention targets for myopia preventive practices in preschool children.

Optical coherence tomographic angiography in children with anisometropic amblyopia

OBJECTIVES

To observe and compare the difference in retinal perfusion using optical coherence tomography angiography (OCTA) between anisometropic amblyopia in children and fellow eyes as well as age-matched controls.

METHODS

A total of 16 children with anisometropic amblyopia and 19 age-matched healthy subjects were enrolled. All participants underwent OCTA examination, with 3 mm × 3 mm and 6 mm × 6 mm scans in the macular region. Perfusion parameters of the superficial retinal layer were measured by built-in software, including the macular foveal avascular zone (FAZ) area, perimeter and circularity, as well as the vessel length density (VLD) and perfusion density (PD) of the foveal, parafoveal and perifoveal regions.

RESULTS

Among the 16 patients with anisometropic amblyopia, the FAZ area was significantly higher in diseased eyes (P = 0.027) than in fellow eyes. The VLD and PD of the foveal average and the VLD of the nasal quadrant of the perifoveal region in anisometropic amblyopic eyes were significantly lower than those in fellow eyes (P < 0.05). The VLD of the parafoveal average, the superior, temporal, inferior and nasal quadrants of the parafoveal region, and the nasal quadrant of the perifoveal region in anisometropic amblyopic eyes were significantly lower than those in healthy controls (P < 0.05). The PD of the parafoveal average, and the inferior quadrant of the parafoveal region in anisometropic amblyopic eyes were significantly lower than those in healthy controls (P < 0.05). The VLD of the parafoveal average, the superior, inferior and nasal quadrants of the parafoveal region, and the nasal quadrant of the perifoveal region in fellow eyes were significantly lower than those in healthy controls (P < 0.05). The PD of the parafoveal average, and the inferior quadrant of the parafoveal region in fellow eyes were significantly lower than those in healthy controls (P < 0.05).

CONCLUSIONS

The macular vessel density of the superficial capillary plexus is lower in anisometropic amblyopic children than in age-matched healthy children. Compared with the fellow eye, the perfusion of the amblyopic eye in children with anisometropic amblyopia also decreases.

Prevalence of and factors associated with astigmatism in preschool children in Wuxi City, China

PURPOSE

To investigate the status of astigmatism in preschool children in Wuxi City, and explore the risk factors related to astigmatism. The risk factors related to astigmatism development as predictors can help us identify preschool children who need vision screening at an early stage to ensure good visual quality.

METHODS

The cross-sectional study was conducted in 10 kindergartens randomly selected in five districts of Wuxi City in November 2018. All preschool children were measured by objective refractometry under non-cycloplegic refraction. The basic information of preschool children was collected. The relevant factors of astigmatism in the questionnaire were completed by parents. Spss 26. 0 software was used for univariate and multivariate correlation analysis.

RESULTS

A total of 889 preschool children participated in the study, 864 were finally included in the study. The prevalence of astigmatism was 36.0%. The risk of astigmatism in premature children was higher than that in non-premature children (adjusted odds ratio = 1.841). The prevalence of astigmatism with parents' astigmatism history was higher, compared with preschool children without parents' astigmatism history (adjusted odds ratio = 2.037). When maternal age at childbirth was older (≥ 35 years old), the risk of astigmatism increased in preschool children (adjusted odds ratio = 2.181). Compared with bottle feeding, the risk of astigmatism for mixed feeding and breastfeeding reduced in preschool children. Compared with preschool children exposed to electronic screen for less than 2 h every day, preschool children exposed to electronic screen for more than 2 h had an increased risk of astigmatism (P = 0.004).

CONCLUSION

The prevalence of astigmatism among preschool children in Wuxi City was high. Some risk factors such as premature birth, parents' astigmatism history, maternal age at childbirth, feeding pattern, and electronic screen exposure time were closely related to the occurrence of astigmatism among preschool children. For preschool children with significant risk factors, their eyesight should be checked regularly to ensure their visual quality.

Accidentally diagnosed ocular abnormalities identified during close screening for retinopathy of prematurity

PURPOSE

To report the variety of ocular findings which have been identified serendipitously during the screening for retinopathy of prematurity (ROP) in a tertiary referral center during seven-year period.

METHODS

The charts of 1568 preterm infants who screened for ROP were reviewed retrospectively. Any ocular lesion except for ROP were noted. All infants had undergone routine ocular examination of the external eye, pupillary light reflex, anterior and posterior segment. Wide-angle digital retinal image acquisition system for any vitreoretinal pathology requiring a close follow-up had been utilized.

RESULTS

Abnormal ocular findings other than ROP were diagnosed in 296 infants (19.2%). Tunica vasculosa lentis was the most common finding (25%) followed by vitreous or retinal hemorrhages (17.2%) and retinal white lesions (16.6%). Retina was the most frequently involved anatomic site. Other frequent ocular findings included optic disc cupping, congenital cataract, optic nerve hypoplasia, choroidal nevus, persistent fetal vasculature, lid hemangioma, and tilted disc. However, life-threatening pathologies such as lipemia retinalis and even retinoblastoma were also diagnosed.

CONCLUSION

A duly ophthalmologic examination is mandatory in premature infants for ROP screening. During such examinations, ophthalmologists must be aware of coexisting ocular findings; which could be sight-threatening or even life-threatening.

Study to establish visual acuity norms with Teller Acuity Cards II for infants from southern China

OBJECTIVES

To establish the norms of binocular and monocular acuity and interocular acuity differences for southern Chinese infants and compare these norms with the results for northern Chinese infants.

METHODS

A prospective, comparative, and noninterventional study was conducted from January to August 2018. Teller Acuity Cards II were used to determine the binocular and monocular acuity of infants. The tolerance intervals and limits with a stated proportion and probability were used to evaluate the norms of binocular and monocular acuity and interocular acuity differences. An unpaired t-test was used to compare the obtained norms with the reported northern Chinese norms.

RESULTS

The tolerance intervals of binocular acuity (mean acuity of 3.73, 7.35, and 12.01 cpd, respectively, at 12, 24, and 36 months), monocular acuity (mean acuity of 2.88, 6.91, and 10.75 cpd, respectively, at 12, 24, and 36 months), and interocular acuity differences (mean difference of 0.92, 2.89, and 3.99 cpd, respectively, at 12, 24, and 36 months) were obtained, exhibiting an increasing trend with age. The binocular visual acuity norms of southern Chinese infants were significantly lower than those in northern China (4.37 vs. 6.9 cpd at 8 months and 7.35 vs. 26 cpd at 24 months) (P = 0.011).

CONCLUSIONS

Northern and southern Chinese infants exhibited distinct acuity norms and visual development patterns. The establishment of population-specific visual acuity norms is necessary for current populations of infants from different regions.

Association between greater residential greenness and decreased risk of preschool myopia and astigmatism

OBJECTIVE

Rapid urbanization has led to reduced greenness in many areas, this has been linked to adverse health outcomes. The aim was to determine the association between residential greenness experienced during very early childhood with preschool myopia and astigmatism and to explore the potential mediating role of screen time on any associations.

METHOD

Information regarding socio-demographic characteristics, home address, screen time during early childhood, and refraction data from vision screenings of 53,575 preschoolers from Longhua Child Cohort Study were collected via questionnaires. Residential greenness was calculated as the average of satellite-derived Normalized Difference Vegetation Index in buffers of 100, 250, and 500 m around each child's home address. Logistic and linear regression models were used to examine the relationships between residential greenness, screen time, and preschool myopia and astigmatism.

RESULT

The mean (SD) age of the 53,575 preschoolers was 5.0 (0.7) years, and 24,849 (46.4%) were girls. A total of 1236 (2.3%) preschoolers had myopia and 5347 (10.0%) had astigmatism. In the adjusted model, a higher neighborhood greenness level within 100 m buffers around the home address was associated with decreased risk of myopia (adjusted odds ratios (AOR): 0.62, 95% confidence interval (CI): 0.38-0.99), and higher neighborhood greenness levels within 100, 250, and 500 m decreased the risk of astigmatism, and their AORs (95% CIs) were 0.55 (0.43-0.70) for 100 m, 0.59 (0.41-0.83) for 250 m, 0.61 (0.42-0.90) for 500 m, respectively. Greater screen time during early childhood increased the risk of myopia (AOR = 1.33) and astigmatism (AOR = 1.23). Reduction in screen time fully mediated the benefits of greater residential greenness on preschool myopia, but partially mediated that on preschool astigmatism (p < 0.05).

CONCLUSION

Higher residential greenness reduces the risk of preschool myopia and astigmatism; the benefits of residential greenness were mediated through reduced daily screen time.

Combination Effect of Outdoor Activity and Screen Exposure on Risk of Preschool Myopia: Findings From Longhua Child Cohort Study

Evidence regarding screen use and outdoor activity during very early childhood (i. e., from aged 1 to 3 years) and their potential combined links to the later preschool myopia is limited. This information is needed to release effective public health messages and propose intervention strategies against preschool myopia. We collected information regarding very early childhood screen use, outdoor activity and the kindergartens vision screenings of 26,611 preschoolers from Longhua Child Cohort Study by questionnaires. Logistic regression models were used to examine the associations between reported outdoor activity, screen use from 1 to 3 years of age, and preschool myopia. Throughout very early childhood, from 1 to 3 years, the proportion of children exposed to screens increased (from 35.8 to 68.4%, p < 0.001), whereas the proportion of children who went outdoors ≥7 times/week (67.4–62.1%, p < 0.001) and who went outdoors for ≥60 min/time (53.3–38.0%, p < 0.001) declined. Exposure to fixed screen devices [adjusted odds ratio (AOR) = 2.66, 95% confidence interval (CI) = 2.09–3.44], mobile screen devices (AOR = 2.76, 95% CI = 2.15–3.58), and limited outdoor activity (AOR = 1.87, 95% CI = 1.42–2.51) during early childhood were associated with preschool myopia. Among children whose parents were myopic, the interactions between outdoor activity and fixed or mobile screen use on later preschool myopia were significant; the ORs and 95% CI were 3.34 (1.19–9.98) and 3.04 (1.06–9.21), respectively. Our findings suggest the possibility that the impact of screen exposure during early childhood on preschool myopia could be diminished by outdoor activity for children whose parents have myopia.

Evidence-Based Clinical Practice Guideline: Comprehensive Pediatric Eye and Vision Examination

Republished with written permission granted from the American Optometric Association, October 2, 2020.

Increased Incidence of Ophthalmologic Findings in Children With Concurrent Isolated Nonsyndromic Metopic Suture Abnormalities and Deformational Cranial Vault Asymmetry

OBJECTIVE

The purpose of this project was to study the incidence of ophthalmologic findings which are known to be risk factors for amblyopia in children who have coexisting metopic suture abnormalities and deformational plagiocephaly (DP) and brachycephaly (DB).

DESIGN

Institutional Review Board-approved retrospective study reviewing records of a consecutive cohort of children under 2 years of age with metopic suture abnormalities and cranial vault asymmetries seen in both the plastic surgery and ophthalmology clinics from 2007 to 2017.

SETTING

Institutional tertiary care center with all care in plastic surgery under the senior author and the standard of care accepted in pediatric ophthalmology under one of two ophthalmologists.

PATIENTS

After application of exclusion criteria, 76 children diagnosed with metopic suture abnormalities and DP/DB were included in the study. Patients with severe trigonocephaly, other suture involvement, syndromic diagnoses, and primary ocular disorders were excluded.

MAIN OUTCOME MEASURES

Describe the incidences of refractive errors (astigmatism, hyperopia, and myopia), anisometropia, strabismus, and amblyopia within the study population.

RESULTS

In our patient population, the rates of amblyopia (17.1%) and strabismus (15.8%) are higher than the general pediatric population rates of 1.5% to 1.8% and 2.4% to 3.6%, respectively. Overall, 47.4% had significant refractive error: 28.9% with astigmatism, 15.8% with hyperopia, 5.3% with myopia, and 10.5% with anisometropia.

CONCLUSIONS

In our patient population, children with coexisting metopic suture abnormalities and DP or DB had significant risk for amblyopia, strabismus, and refractive errors.

[Myopia in children]

Myopia is a refractive anomaly, a global public health issue, mainly due to an increase in axial length of the eyeball. Myopia is increasing worldwide with the appearance of a "myopia global growing epidemic". In children under 6 years old, 20 % have abnormalities, the most common of which are primarily refractive abnormalities, followed by strabismus and amblyopia. Myopia presents a major risk of complications, correlated with its severity, such as retinal detachment, retinal neovascularization, early cataracts and glaucoma. In children with high myopia, syndromic myopia must be explored. Early detection of myopia onset and progression is essential to myopia control strategies. The most promising treatments include outdoor activities, defocusing corrective lenses, defocusing contact lenses, orthokeratology and pharmacological treatments with low-dose atropine.

Prevalence and causes of infantile nystagmus in a large population-based Danish cohort

PURPOSE

The aim of this study was to provide a population-based estimate on the prevalence of infantile nystagmus and to describe the causes in the Capital Region of Denmark.

METHODS

Review of medical records of children with infantile nystagmus born in the period 1 January 2010 through 31 December 2017 and living in the Capital Region of Denmark. We used birth registry data from Statistics Denmark and the National Danish Birth Registry to calculate the prevalence of nystagmus in children born at term and prematurely.

RESULTS

A total of 103 patients (52 males/51 females) with infantile nystagmus were included. The overall prevalence of infantile nystagmus was 6.1 per 10 000 live births. It was higher in premature children (28.4/10 000 live births) than children born at term (4.4/10 000), p < 0.0001, and highest in children born extremely preterm, (97.3/10 000). The most common cause of infantile nystagmus was ocular disease (44%) followed by idiopathic nystagmus (32%), neurological disorders and genetic syndromes (20%) and prematurity without retinopathy of prematurity as the only cause (4%).

CONCLUSIONS

In this study, we provide the prevalence of infantile nystagmus based on national medical records in which all residents are accounted for. Our findings show a prevalence of 6.1 per 10 000 live births but six times higher among children born preterm than born at term. Ocular disease was the leading cause of infantile nystagmus with albinism and ocular malformations as the most frequent. In 1/3 of patients, no cause could be identified.

Crx Is Posttranscriptionally Regulated by Light Stimulation in Postnatal Rat Retina

Cone rod homeobox (Crx) plays a key role at the center of a regulatory network that coordinates many pathways in the retina. Its abnormal expression induces retinal disorders. However, the underlying regulatory mechanism of Crx expression is not well defined. Here, we present data that show that the levels of Crx mRNA were inconsistent with that of Crx protein in primary retinal neurocytes cultured in light conditions. Crx protein levels were significantly higher (2.56-fold) in cells cultured in the dark than in cells cultured in light, whereas Crx mRNA was not changed in either type of cell. Moreover, the expression of Crx protein showed a significant light intensity-dependent decrease. Consistently, Crx downstream genes rhodopsin and arrestin also decreased in retinal neurocytes upon light exposure. Furthermore, Crx promoter activity assay performed in primary retinal neurocytes further indicated that light exposure and darkness did not affect its inducibility. In addition, the inconsistency between Crx mRNA and protein expression after light exposure was not observed in 661w cells transfected with plasmid pcDNA3.1-Crx, suggesting that the inconsistency between Crx mRNA and protein induced by light was specific to the endogenous Crx. More importantly, this observation was confirmed in vivo in postnatal day 15 (P15) retinas but not in adult retinas, further implicating that the posttranscriptional regulation mechanism may be involved in Crx expression in the developing retina. Therefore, our study sheds light on the mechanism of Crx expression in postnatal rat retina.

Screen Exposure during Early Life and the Increased Risk of Astigmatism among Preschool Children: Findings from Longhua Child Cohort Study

Screen media usage has become increasingly prevalent in daily life with children being exposed to screens at an early age. This is a growing public health concern with evidence linking screen exposure to detrimental health outcomes, whereas relationship between screen exposure and the presence of astigmatism among preschoolers remains unknown, thus we aimed to resolve this issue. During the 2017 survey of the Longhua Child Cohort Study, data of 29,595 preschoolers were collected via a caregiver-reported questionnaire regarding socio-demographics, screen exposure and refraction. Cox regression models were adopted to generate adjusted prevalence ratios (APR) and 95% confidence intervals (CI) to estimate the association between early screen exposure and astigmatism. 28,029 preschoolers were included in the final analysis. After adjustment for potential confounders, screen exposure during early life was significantly associated with the increased risk of astigmatism (APR and 95% CI: 2.25, 1.76–2.88), and the greatest risk was observed in the period from birth to 1-year (APR and 95% CI: 3.10, 2.41–3.98). The risk of astigmatism increased with both the total years of exposure and the average daily duration of screen exposure. Our findings suggested that preschoolers who were exposed to screens during early life might have an increased risk of astigmatism.

Antibiotic-induced dysbiosis of gut microbiota impairs corneal development in postnatal mice by affecting CCR2 negative macrophage distribution

Antibiotics are extremely useful, but they can cause adverse impacts on host bodies. We found that antibiotic treatment altered the composition of the gut microbiota and the gene expression profile in the corneal tissues of postnatal mice and decreased the corneal size and thickness, the angiogenesis of limbal blood vessels, and the neurogenesis of corneal nerve fibers. The reconstitution of the gut microbiota with fecal transplants in antibiotic-treated mice largely reversed these impairments in corneal development. Furthermore, C-C chemokine receptor type 2 negative (CCR2^-) macrophages were confirmed to participate in corneal development, and their distribution in the cornea was regulated by the gut microbiota. We propose that the CCR2^- macrophage population is a crucial mediator through which gut microbiota affect corneal development in postnatal mice. In addition, probiotics were shown to have the potential effect of restoring corneal development in antibiotic-treated mice. Abx-induced gut dysbiosis has significant, long-term effects on the development of the cornea, and reversal of these suppressive effects takes a long time.

Associations between Environmental Tobacco Smoke Exposure in Early Life and Astigmatism among Chinese Preschool Children

This study aimed to investigate the association between environmental exposure to tobacco smoke (ETS) during early life and astigmatism in Chinese preschool children. In this cross-sectional study, information concerning prenatal and postnatal ETS exposure at three stages of early life (during pregnancy, from birth to one year and from one to three years), visual problems of children and parents (including a confirmed diagnosis of astigmatism), socio-demographics and perinatal characteristics were obtained from 27,890 parent-reported questionnaires. Logistic regression analyses were undertaken to yield adjusted odds ratios (OR) for assessing their associations. After adjusting for the potential confounders, children were more likely to exhibit astigmatism when they were exposed to ETS during pregnancy + from one to three years [OR (95% CI) = 1.37 (1.02, 1.84)], or from birth to one year + from one to three years [OR (95% CI) = 1.36 (1.11, 1.66)], or during pregnancy + from birth to one year + from one to three years old [OR (95% CI) = 1.29 (1.16, 1.45)], compared to children without ETS exposure at any stage of early life. In Chinese preschool children, prenatal and postnatal astigmatism was associated with ETS exposure; the greater the ETS dose, the greater the astigmatism risk.

Performing pediatric eye exams in primary care

Early vision care is critical for all children. If undetected, eye disorders such as amblyopia and strabismus may result in permanent vision loss. Vision exams should include a careful history and physical including fix and follow, red reflex, and cover/uncover testing. Photo screening and visual acuity exams should be administered whenever possible.

Low availability of choline in utero disrupts development and function of the retina

Adequate supply of choline, an essential nutrient, is necessary to support proper brain development. Whether prenatal choline availability plays a role in development of the visual system is currently unknown. In this study, we addressed the role of in utero choline supply for the development and later function of the retina in a mouse model. We lowered choline availability in the maternal diet during pregnancy and assessed proliferative and differentiation properties of retinal progenitor cells (RPCs) in the developing prenatal retina, as well as visual function in adult offspring. We report that low choline availability during retinogenesis leads to persistent retinal cytoarchitectural defects, ranging from focal lesions with displacement of retinal neurons into subretinal space to severe hypocellularity and ultrastructural defects in photoreceptor organization. We further show that low choline availability impairs timely differentiation of retinal neuronal cells, such that the densities of early-born retinal ganglion cells, amacrine and horizontal cells, as well as cone photoreceptor precursors, are reduced in low choline embryonic d 17.5 retinas. Maintenance of higher proportions of RPCs that fail to exit the cell cycle underlies aberrant neuronal differentiation in low choline embryos. Increased RPC cell cycle length, and associated reduction in neurofibromin 2/Merlin protein, an upstream regulator of the Hippo signaling pathway, at least in part, explain aberrant neurogenesis in low choline retinas. Furthermore, we find that animals exposed to low choline diet in utero exhibit a significant degree of intraindividual variation in vision, characterized by marked functional discrepancy between the 2 eyes in individual animals. Together, our findings demonstrate, for the first time, that choline availability plays an essential role in the regulation of temporal progression of retinogenesis and provide evidence for the importance of adequate supply of choline for proper development of the visual system.-Trujillo-Gonzalez, I., Friday, W. B., Munson, C. A., Bachleda, A., Weiss, E. R., Alam, N. M., Sha, W., Zeisel, S. H., Surzenko, N. Low availability of choline in utero disrupts development and function of the retina.

Pediatric optic nerve and optic nerve sheath diameter on magnetic resonance imaging

BACKGROUND

The normal values of optic nerve diameter and optic nerve sheath diameter might be beneficial in defining an abnormality such as optic nerve hypoplasia, or enlarged subarachnoid space, reflecting the state of increased intracranial pressure.

OBJECTIVE

To study the normal optic nerve diameter and optic nerve sheath diameter on magnetic resonance imaging (MRI) in the early years of postnatal visual development from MRI of the brain.

MATERIALS AND METHODS

MRI of the brain in patients ages 4 years and younger were gathered. Forty-two studies with normal intracranial findings and a lack of history of increased intracranial pressure were retrospectively reviewed by two reviewers using axial T2-weighted images. Measurements were performed in transverse diameter perpendicular to the optic nerve at 3 mm behind the globe.

RESULTS

The mean optic nerve diameter of the 77 optic nerves were 2.5 mm (95% confidence interval [CI] 2.4-2.6). The mean optic nerve sheath diameter values of the 79 optic nerve sheath complexes were 5.0 mm (95% CI 4.9-5.1). The mean±standard deviation optic nerve diameter and optic nerve sheath diameter stratified by each age groups were, respectively, 0 to <1 year: 2.3±0.40 and 4.81±0.37; 1 to <2 years: 2.6±0.2 and 5.0±0.4; 2 to <3 years: 2.4±0.3 and 4.9±0.6, and 3 to <4 years: 2.9±0.4 and 5.2±0.60 mm.

CONCLUSION

Seventy-four of the 77 measurements (96%) were of the measurements were above the threshold of 2 mm for optic nerve diameter. Seventy-seven of the 79 measurements (97%) were of the measurements were below the threshold of 6 mm for optic nerve sheath diameter.

Brain functional development separates into three distinct time periods in the first two years of life

Recently, resting functional MRI has provided invaluable insight into the brain developmental processes of early infancy and childhood. A common feature of previous functional development studies is the use of age to separate subjects into different cohorts for group comparisons. However, functional maturation paces vary tremendously from subject to subject. Since this is particularly true for the first years of life, an alternative to physical age alone is needed for cluster analysis. Here, a data-driven approach based on individual brain functional connectivity was employed to cluster typically developing children who were longitudinally imaged using MRI without sedation for the first two years of life. Specifically, three time periods were determined based on the distinction of brain functional connectivity patterns, including 0-1 month (group 1), 2-7 months (group 2), and 8-24 (group 3) of age, respectively. From groups 1 to 2, connection density increased by almost two-fold, local efficacy (LE) is significantly improved, and there was no change in global efficiency (GE). From groups 2 to 3, connection density increased slightly, LE showed no change, and a significant increase in GE were observed. Furthermore, 27 core brain regions were identified which yielded clustering results that resemble those obtained using all brain regions. These core regions were largely associated with the motor, visual and language functional domains as well as regions associated with higher order cognitive functional domains. Both visual and language functional domains exhibited a persistent and significant increase within domain connection from groups 1 to 3, while no changes were observed for the motor domain. In contrast, while a reduction of inter-domain connection was the general developmental pattern, the motor domain exhibited an interesting "V" shape pattern in its relationship to visual and language associated areas, showing a decrease from groups 1 to 2, followed by an increase from groups 2 to 3. In summary, our results offer new insights into functional brain development and identify 27 core brain regions critically important for early brain development.

Maturation of Binocular, Monocular Grating Acuity and of the Visual Interocular Difference in the First 2 Years of Life

The sweep visual evoked potential method (sVEP) is a powerful tool for measurement of visual acuity in infants. Despite the applicability and reliability of the technique in measuring visual functions the understanding of sVEP acuity maturation and how interocular difference of acuity develops in early infancy, as well as the availability of normality ranges, are rare in the literature. We measured binocular and monocular sVEPS acuities in 481 healthy infants aged from birth to 24 months without ophthalmological diseases. Binocular sVEP acuity was significantly higher than monocular visual acuities for almost all ages. Maturation of monocular sVEP acuity showed 2 longer critical periods while binocular acuity showed three maturation periods in the same age range. We found a systematic variation of the mean interocular acuity difference (IAD) range according to age from 1.45 cpd at birth to 0.31 cpd at 24 months. An additional contribution was the determination of sVEP acuity norms for the entire age range. We conclude that binocular and monocular sVEP acuities have distinct growth curves reflecting different maturation profiles for each function. Differences in IAD range shorten according to age and they should be considered in using the sVEP acuity measurements for clinical diagnosis as amblyopia.

New pediatric risk factors for amblyopia: strabismic versus refractive

PURPOSE

To assess the role of risk factors for amblyopia, such as family history and neonatal background, for the prediction of either strabismic amblyopia or refractive amblyopia.

METHODS

In this retrospective case-control model, the study population included all children born at the Hospital de Braga during 1997-2012 (3 to 18 years old) with ophthalmologic consultation in 2014. Data collection was performed from the clinical database and through telephone questionnaire surveys.

RESULTS

A total of 298 (50%) controls and 298 (50%) cases (120 [40.3%] strabismic amblyopia and 178 [59.7%] refractive amblyopia) were analyzed. A significantly lower birthweight was detected in patients with strabismic amblyopia (mean 2,961 g [95% confidence interval (CI) 2,827-3,096]) compared to controls (mean 3,198 g [95% CI 3,125-3,271]) (p = 0.002). Five-minute Apgar was significantly lower in patients with strabismic amblyopia (mean 9.57 [95% CI 9.37-9.77]) than in controls (mean 9.83 [95% CI 9.77-9.90]) (p = 0.004) or patients with refractive amblyopia (mean 9.79 [95% CI 9.69-9.89]) (p = 0.031). Family history of either amblyopia or strabismus was associated with amblyopia (χ² [2, n = 562] = 12.66; p = 0.002; Cramer V = 0.150; χ² [2, n = 561] = 11.0; p = 0.004; Cramer V = 0.140), but was significantly more associated with strabismic amblyopia (p = 0.0023 and p = 0.0032) than with refractive amblyopia (p = 0.48 and p = 0.015, respectively). Multinomial logistic regression model explained 50.8% of the variance in amblyopia development. Low 5-minute Apgar had a relevant odds ratio (OR) for either strabismic amblyopia (OR 3.44; p = 0.066) or refractive amblyopia (OR 3.30; p = 0.077).

CONCLUSIONS

This division in amblyopia subtypes gives a new perspective of the risk factors for amblyopia, with family history and some obstetrician/neonatal outcomes appearing to be more relevant in strabismic amblyopia. Educating health care providers to recognize these risk factors can result in an early ophthalmologic referral.

In vivo optical imaging of amblyopia: Digital subtraction autofluorescence and split-spectrum amplitude-decorrelation angiography

BACKGROUND AND OBJECTIVES

Amblyopia is a visual impairment that is attributed to either abnormal binocular interactions or visual deprivation. The retina and choroids have been shown to be involved in the development of amblyopia. The purpose of this study was to investigate the retinal and choroidal microstructural abnormalities of amblyopia using digital subtraction autofluorescence and split-spectrum amplitude-decorrelation angiography (SSADA) approaches.

METHODS

This prospective study included 44 eyes of 22 patients with unilateral amblyopia. All patients who received indirect ophthalmoscopy, combined depth imaging spectral domain optical coherence tomography (OCT), SSADA-OCT, and macular blue light (BL-) and near-infrared (NIR-) autofluorescences underwent pupil dilation. The subfoveal choroidal thickness (SFCT) was measured. BL- and NIR-autofluorescences were determined for all patients and used to generate subtraction images with ImageJ software. The superficial, deep layers of the retina, and inner choroid layer were required for SSADA-OCT.

RESULTS

For the normal eyes, a regularly increasing signal was observed in the central macula based on the subtraction images. In contrast, a decreased signal for the central patch or a reduced peak was detected in 16 of 22 amblyopic eyes (72.7%). The mean SFCT of the amblyopic eyes was greater than that of the fellow normal eyes (399.25 ± 4.944 µm vs. 280.58 ± 6.491 µm, respectively, P < 0.05). SSADA-OCT revealed a normal choroidal capillary network in all fellow normal eyes. However, 18 of 22 amblyopic eyes (86.4%) exhibited a blurry choroidal capillary network, and 15 of 22 amblyopic eyes (68.2%) displayed a dark atrophic patch.

CONCLUSIONS

This is the first report of amblyopia using SSADA-OCT and digital subtraction images of autofluorescence. The mechanistic relationship of a thicker choroid and choroidal capillary atrophy with amblyopia remains to be described. The digital subtraction image confirmed the changes in the microstructure of the amblyopic retina as a supplementary approach to detect the progression of amblyopia. Lasers Surg. Med. 48:660-667, 2016. © 2016 Wiley Periodicals, Inc.

Distribution of Axial Length before Cataract Surgery in Chinese Pediatric Patients

Axial length (AL) is a significant indicator of eyeball development, but reports on the overall status of axial development in congenital cataract (CC) patients and its relationship with patient demographics, such as age, sex, and laterality, are rare. We prospectively investigated the AL of 1,586 patients ≤18 years old and undergoing cataract surgery in China from January 2005 to December 2014. Of these 3,172 eyes, a logarithmic correlation between AL and age in CC patients was calculated, and an age of approximately 2 years was found to be a turning point in the growth rate of AL. A considerable variation was observed in CC patients of the same age. Furthermore, 2–6 years old boys had longer AL than girls. The AL of affected eye in unilateral patients was longer than that of the contralateral eye in 2–6 years age group and longer than that of eye in bilateral CC patients in all age groups. These findings indicate that the development of the length of eyeballs in CC patients is influenced by multiple factors in addition to age. A full understanding of the distribution of AL may provide a useful reference for judging the timing of surgery in CC patients.

Prevalence of Corneal Astigmatism and Anterior Segmental Biometry Characteristics Before Surgery in Chinese Congenital Cataract Patients

The prevalence and the distribution characteristics of corneal astigmatism (CA) and anterior segment biometry before surgery in Chinese congenital cataract (CC) patients are not completely understood. This study involved 400 CC patients from the Zhongshan Ophthalmic Center enrolled from February 2011 to August 2015. Data on CA, keratometry, central corneal thickness (CCT) and anterior chamber depth (ACD) were measured by the Pentacam Scheimpflug System. The mean age of patients was 54.27 months, and the ratio of boys to girls was 1.53:1. The mean CA was 2.03 diopters (D), and 39.25% of subjects had CA values ≥2 D. The most frequent (71.8%) diagnosis was with-the-rule astigmatism. Oblique astigmatism was present in 16.2% of cases, and 12% of cases had against-the-rule astigmatism. The mean keratometry measurement of cataractous eyes in bilateral patients was significantly larger than that in unilateral patients. Girls had a larger mean keratometry but a thinner CCT than did boys. The CA, CCT, and ACD of cataractous eyes were significantly larger than those of non-cataractous eyes in unilateral patients. The CA, mean keratometry, CCT, and ACD in CC patients varied with age, gender, and laterality. Fully understanding these characteristics may help inform guidelines and treatment decisions in CC patients.

Horizontal Tonic Conjugate Gaze Deviation in a 4-Week-Old Infant: What Can the Eyes (of the Parents) Tell?

A 4-week-old healthy infant failed to make eye contact when approached from the left. When evaluated by us at the age of 11 weeks, left tonic conjugate gaze deviation was noted. Brain MRI showed a left frontotemporal large tension arachnoid cyst causing right falcial herniation. During the insertion of an Ommaya reservoir, hemosiderin was found to be coating the inner wall of the cyst, which may indicate that the asymptomatic cyst evolved to a tension cyst due to spontaneous hemorrhage. Surgical decompression resulted in complete restoration of the horizontal gaze and considerable reduction in the size of the cyst. After 3 months a cystoperitoneal shunt was placed due to increased intracranial pressure secondary to impaired drainage of the cyst. Since then the infant has done well, with normal developmental and neurological examination during his last follow-up at the age of 5 years. Although gaze central ocular motor control is still underdeveloped and chaotic eye movements are present during early infancy, the present case report reminds us that a thorough examination of eye movements should not be overlooked during neurodevelopmental evaluation.

Risk and benefit assessment of potential neurodevelopmental effect resulting from consumption of marine fish from a coastal archipelago in China

The aim of this study was to assess net neurodevelopmental effect via maternal consumption of marine fish. A total of thirty-one species were collected from Zhoushan, China. The net IQ point gain was assessed by FAO/WHO deterministic approach and probabilistic computation (if necessary). Results of the deterministic assessment of two samples belonging to Scoliodon sorrakowah showed negative IQ point gain in both common and extreme consumption scenarios (175 and 450 g/week, respectively); the net IQ gain caused by both consumption scenarios of other species were positive. Both consumption scenarios of Scoliodon sorrakowah showed beneficial neurodevelopmental effect according to probabilistic computation (95% CI for mean of net IQ gain: 0.0536-0.0554 and 0.1377-0.1425, respectively). Except for Scoliodon sorrakowah, this study indicates that both consumption scenarios of other studied species would be recommended according to the FAO/WHO approach. There would be no recommendation of consumption scenarios of Scoliodon sorrakowah for the reason for carefulness.

Whole genome expression profiling of normal human fetal and adult ocular tissues

To study growth and development of ocular tissues, gene expression patterns in normal human fetal versus adult eyes were compared. Human retina/retinal pigment epithelium, choroid, sclera, optic nerve* and cornea* tissues were dissected from fetal (24 week gestational age) (N = 9; *N = 6), and adult (N = 6) normal donor eyes. The Illumina(®) whole genome expression microarray platform was used to assess differential expression. Statistical significance for all comparisons was determined using the Benjamin and Hochberg False Discovery Rate (FDR, 5%). Significant gene expression fold changes > 1.5 were found in adult versus fetal retina/RPE (N = 1185), choroid (N = 6446), sclera (N = 1349), and cornea (N = 3872), but not optic nerve. Genes showing differential expression were assessed using Ingenuity Pathway Analysis (IPA) for enriched functions and canonical pathways. In all tissues, development, cell death/growth, cancer functions, and signaling canonical pathways were enriched. There was also a general trend of down-regulation of collagen genes in adult tissues.

White matter injury in preterm infants: could human milk play a role in its prevention?

Human milk has been found to be beneficial for the development of all newborns. It is protective during the development of the gastrointestinal tract, important in neurologic development, immune system function, and nourishment. Human milk has a number of components that aid in the anti-inflammatory process and free radical reduction and is a building block for neurologic development. Cerebral white matter injury is a common occurrence in preterm infants. Results of this injury can be seen into early childhood and throughout the life of the individual. White matter injury most frequently occurs because of hypoxia and the inflammatory process, which often results in the injury of myelinating oligodendrites. This article proposes the potential importance of human milk in slowing and preventing cerebral white matter injury because of the components in human milk that affect the inflammatory and free radical reduction processes. It also proposes its ability to provide nutrients essential to myelin development.

Evaluation of peripapillary retinal nerve fiber layer, macula and ganglion cell thickness in amblyopia using spectral optical coherence tomography

AIM

To investigate peripapillary retinal nerve fiber layer (RNFL), macula and ganglion cell layer thicknesses (GCC) in amblyopic eyes with spectral domain optical coherence tomography (SD-OCT).

METHODS

Thirty six patients with a history of unilateral amblyopia and thirty two children who had emmetropia without amblyopia were included in this study. In this institutional study, 36 eyes of 36 patients with amblyopia (AE), 36 fellow eyes without amblyopia (FE), and 32 eyes of 32 normal subjects (NE) were included. RNFL, GCC and macular thickness measurements were performed with RS-3000 OCT Retina Scan (Nidek Inc CA. USA).

RESULTS

The mean global thicknesses of the RNFL were 113.22±21.47, 111.57±18.25, 109.96±11.31µm in the AE, FE, and NE, respectively. There was no statistically significant difference for mean global RNFL thickness among the eyes (P=0.13). The mean thicknesses of the macula were 258.25±18.31, 258.75±19.54, 248.62±10.57µm in the AE, FE and NE, respectively. There was no statistically significant difference for thickness of macula among the eyes (P=0.06). The GCC was investigated into two parts: superior and inferior. The mean thicknesses of superior GCC were 102.57±13.32, 103.32±10.64, 100.52±5.88µm in the AE, FE, and NE, respectively. The mean thicknesses of inferior GCC were 103.82±12.60, 107.82±12.33, 105.86±10.79µm in the AE, FE and NE, respectively. There was no statistically significant difference for thickness of superior and inferior GCC between the eyes (P=0.63, P=0.46).

CONCLUSION

The macular thicknesses of AE and FE were greater than the NE, although it was not statistically significant. Amblyopia does not seem to have a profound effect on the RNFL, macula and GCC.

The unfolded protein response is activated in connexin 50 mutant mouse lenses

The unfolded protein response is a set of cell signaling pathways recently recognized to be activated in the lens during both normal development and endoplasmic reticulum stress induced by either unfolded proteins or oxidative damage. While mutations in the gene for connexin 50 are known to cause autosomal dominant cataracts, it has not been previously reported whether mutant connexins can activate the unfolded protein response in the lens. Mice homozygous for the S50P or G22R mutation of connexin 50 have reduced amounts of connexin 50 protein at the cell membrane, with some intracellular staining consistent with retention in the endoplasmic reticulum. Connexin 50 mutants have elevated levels of BiP expression in both lens epithelial and fiber cells from E15.5 with the most robust elevation detected in newborns. While this elevation decreases in magnitude postnatally, BiP expression is still abnormally high in adults, particularly in the perinuclear endoplasmic reticulum of cell nuclei that are inappropriately retained in adult homozygous mutant lenses. Xbp1 splicing was elevated in lenses from both connexin mutants studied, while Atf4 and Atf6 levels were not majorly affected. Overall, these data suggest that UPR may be a contributing factor to the phenotype of connexin 50 mutant lenses even though the relatively modest extent of the response suggests that it is unlikely to be a major driver of the pathology.