Infant Vision Research Articles

Macular thickness analysis using optical coherence tomography data, stereopsis and binocular vision in premature infants who underwent retinal laser photocoagulation due to retinopathy of prematurity in an age-related perspective

Macular thickness analysis using optical coherence tomography data, stereopsis and binocular vision in premature infants who underwent retinal laser photocoagulation due to retinopathy of prematurity in an age-related perspective

Development of Automated Visual Acuity Measurement Using a Calibration-Free Eye-Tracking System.

Purpose Infant vision assessment often relies on grating acuity; however, its objectivity and convenience must be improved. A calibration-free eye-tracking system, even in preverbal children, enables easy and precise gaze analysis. This pilot study aimed to develop a reliable automated monocular vision screening. Methods Participants (n=118) underwent a grating visual acuity test using the eye-tracking system. Correlations between the grating acuity, uncorrected visual acuity, and refractive error were analyzed across different cutoff values of fixation duration percentage. Results Strong correlations were found between the grating acuity and refractive error at 69% and 88% thresholds. Similar correlations with uncorrected visual acuity were noted at 70% and 89% thresholds. False-negatives around the 70% threshold were noted, indicating potential overestimation of acuity in cases of low visual acuity/high refractive error. Discussion The results highlight the feasibility of calibration-free eye-tracking system-based monocular vision screening with an optimal screening threshold of 90%.

The utility and reliability of the PreViAs questionnaire forthe assessment of vision in Turkish neonates and infants.

Introduction: Evaluating the visual functions of children with an easy-to-use and evidence-based method during the preverbal period will enable early diagnosis and intervention of visual impairments. The aim of this study is to determine the utility and reliability of the Turkish version of the Preverbal Visual Assessment (PreViAs) questionnaire, which was developed to evaluate the visual functioning of preverbal infants. Population and Methods: The PreViAs questionnaire was administered to primary caregivers of term infants under 24 months of age, and their responses were recorded. Results: Data from the 278 participating infants were analyzed to assess the internal consistency of the PreViAs questionnaire. Results showed a high level of consistency with Cronbach's alpha value of 0.958 for the total score, suggesting strong internal coherence. In addition, the Cronbach's alpha values for each domain were 0.890, 0.913, 0.951, and 0.922 for visual attention, visual communication, visual processing, and visual-motor coordination, respectively, indicating good internal consistency for each subdomain. Conclusion: The Turkish version of the PreViAs questionnaire is useful and reliable for assessing functional vision during the preverbal period.

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

Premature newborns have a higher risk of abnormal visual development and visual impairment. To develop a computational methodology to help assess functional vision in premature infants by tracking iris distances. 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. 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. 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.

Propranolol: a new pharmacologic approach to counter retinopathy of prematurity progression.

Despite the evident progress in neonatal medicine, retinopathy of prematurity (ROP) remains a serious threat to the vision of premature infants, due to a still partial understanding of the mechanisms underlying the development of this disease and the lack of drugs capable of arresting its progression. Although ROP is a multifactorial disease, retinal vascularization is strictly dependent on oxygen concentration. The exposition of the retina of a preterm newborn, still incompletely vascularized, to an atmosphere relatively hyperoxic, as the extrauterine environment, induces the downregulation of proangiogenic factors and therefore the interruption of vascularization (first ischemic phase of ROP). However, over the following weeks, the growing metabolic requirement of this ischemic retina produces a progressive hypoxia that specularly promotes the surge of proangiogenic factors, finally leading to proliferative retinopathy (second proliferative phase of ROP). The demonstration that the noradrenergic system is actively involved in the coupling between hypoxia and the induction of vasculogenesis paved the way for a pharmacologic intervention aimed at counteracting the interaction of noradrenaline with specific receptors and consequently the progression of ROP. A similar trend has been observed in infantile hemangiomas, the most common vascular lesion of childhood induced by pre-existing hypoxia, which shares similar characteristics with ROP. The fact that propranolol, an unselective antagonist of β1/2 adrenoceptors, counteracts the growth of infantile hemangiomas, suggested the idea of testing the efficacy of propranolol in infants with ROP. From preclinical studies, ongoing clinical trials demonstrated that topical administration of propranolol likely represents the optimal approach to reconcile its efficacy and maximum safety. Given the strict relationship between vessels and neurons, recovering retinal vascularization with propranolol may add further efficacy to prevent retinal dysfunction. In conclusion, the strategy of contrasting precociously the progression of the disease appears to be more advantageous than the current wait-and-see therapeutic approach, which instead is mainly focused on avoiding retinal detachment.

Newborn and infant vision screening in primary care: A clinical review.

Newborn and infant vision screening is an essential component of the health promotion visit, where the provider screens for ocular risk factors and abnormalities that may cause future impairment or vision loss. Providers may underestimate the importance of screening or find neonatal vision assessments difficult due to poor patient cooperation or time-consuming exams, but the reversibility of vision impairment in infants makes early detection paramount to proper treatment. This article provides a clinical review of evidence-based, practical guidance to providers who care for infants from birth through 6 months of age in the primary care setting. The comprehensive eye exam in infants should include a thorough history and physical examination of eye structures, visual acuity, evaluation of extraocular movements and alignment, and assessment of the red reflex. Recommended exam maneuvers differ with age as visual acuity improves and development advances through infancy. Early detection of ocular pathology is critical to avoid permanent vision loss, serious morbidity, and even mortality. The seemingly complex vision screening exam can be completed with little to no cooperation from the patient when a competent pediatric healthcare provider prioritizes opportunistic exam maneuvers. The opportunistic exam allows providers to maximize efficiency while maintaining thorough technique during vision exams and screenings.

A prospective cohort study on visual development in infants and young children

Objective: This study aimed to analyze the trends and characteristics of early visual development in infants and young children. Methods: A prospective cohort study was conducted, including full-term infants born between 2008 and 2013 at the Maternal and Child Health Hospital in Sanhe City, Hebei Province, China. Visual acuity was assessed at three time points 42 days after birth, 9 months of age, and 18 months of age, using the Teller Acuity Card Ⅱ (TAC Ⅱ) grating visual acuity test. At 3 years of age, visual acuity was assessed using the Lea Symbols chart and converted to grating visual acuity. Visual acuity of both eyes was measured at 42 days, 9 months, and 18 months. For children at 9 and 18 months, monocular visual acuity was also assessed, while at 3 years of age, monocular visual acuity was measured. Visual acuity measurements at different time points and changes in visual acuity within each period were recorded. The visual development of the participants was analyzed and compared with previous literature results. Results: A total of 1 496 children were included in the study, including 773 males (51.67%) and 723 females (48.33%). The binocular visual acuity at 42 days, 9 months, and 18 months was 0.9 (0.6, 1.1), 6.4 (6.4, 9.6), and 9.6 (9.6, 9.6) cycles per degree (cpd), respectively, with statistically significant differences (P<0.001). Visual acuity increased by a factor of 3.21±0.70 between 42 days and 9 months, and by a factor of 0.23±0.48 between 9 and 18 months. At 9 months of age, the monocular visual acuity in the right and left eyes was 6.4 (4.8, 6.4) cpd, which remained the same at 18 months, and the median visual acuity at 3 years of age for both eyes was 18.75 cpd, with a Snellen visual acuity of 20/32 (20/40, 20/32). The differences in binocular visual acuity at each time point were not statistically significant (all P>0.05). At 9 months of age, 68.7%(633/921) of children had visual acuity of ≥6.5 cpd, which increased to 92.7%(342/369) at 18 months. Monocular visual acuity increased by a factor of 0.26±0.46 between 9 and 18 months, and by a factor of 1.36±0.52 between 18 months and 3 years. At 9 months of age, 72.01% (921 out of 1 279) of children who completed binocular visual acuity testing also underwent monocular visual acuity testing, while this proportion decreased to 35.83% (369 out of 1 030) at 18 months. Visual acuity improved with increasing age (P<0.001). The visual acuity of children at each age group in this study was higher than that reported in the literature for children in Guangzhou (P<0.001). Conclusions: The visual acuity of healthy infants and young children below 3 years of age improves with age. Visual development progresses rapidly before 9 months of age, slows down afterward, and then resumes rapid growth at 18 months of age.

Comprehensive prevention strategies for retinopathy of prematurity: a literature review

Abstract Retinopathy of prematurity (ROP) is a kind of disease that can be seen in premature infants. It may cause a series of short- and long-term complications such as poor vision in premature infants, causing irreversible damage to them. Therefore, if we can prevent this disease, we can solve the above problems. This study summarized some factors that influence ROP, such as low gestational age, low birth weight, irrational oxygen use, anemia, blood transfusion, and thrombocytopenia; and also summarized a series of interventions that can prevent or delay the progression of ROP, such as reducing blood transfusion, the application of antenatal corticosteroids, and delaying clip umbilical cord, which can provide some reference for better clinical practice of preventing ROP.

Automated assessment of grating acuity in infants and toddlers using an eye-tracking system.

The purpose of this study was to assess the feasibility of testing binocular visual acuity using the automated acuity card procedure (AACP)-a new automated method that uses an eye-tracking system. We included participants aged 5 to 36 months old. Binocular grating acuity was tested using the AACP and Teller Acuity Cards (TACs) with a uniform testing distance (55 cm) in random order. Electronic stimuli in the AACP were similar in size and form to TACII and roughly equivalent to the printed TACII stimuli. The AACP tracked the participant's gaze from the recorded image sequences and automatically determined the grating acuity. Differentiation, correlation, and consistency were compared between the AACP and TACs. Ultimately, 77.11% (155/201) of participants completed both tests. Fewer participants failed the TAC test than the AACP (15 [7.46%] vs. 31 [15.42%]). The average duration of the AACP (median interquartile range [IQR] = 60 [IQR = 41] seconds) was significantly shorter than that of the TAC (median [IQR], 185 [IQR = 66] seconds, p < 0.001). AACP and TAC visual acuities were robustly correlated (r = 0.83, p < 0.001). Bland-Altman plots revealed a mean difference between AACP and TAC visual acuities of 0.10 cycles per degree (cpd; 95% limits of agreement = 7.70 cpd). Both the AACP and TACs indicated improved visual acuity with age progression (both, p < 0.001), with no significant differences between the tests. Electronic stimuli were presented using the AACP yielded clinically useful data on grating acuity in infants and toddlers. AACP performance was comparable to that of TACs, the current clinical gold standard for assessing infant vision regarding testability, reliability, and accuracy.

Mechanisms of Sodium-Acetate-Induced DHA Accumulation in a DHA-Producing Microalga, Crypthecodinium sp. SUN.

Docosahexaenoic acid (DHA) is an omega-3 polyunsaturated fatty acid (PUFA) that is critical for the intelligence and visual development of infants. Crypthecodinium is the first microalga approved by the Food and Drug Administration for DHA production, but its relatively high intracellular starch content restricts fatty acid accumulation. In this study, different carbon sources, including glucose (G), sodium acetate (S) and mixed carbon (M), were used to investigate the regulatory mechanisms of intracellular organic carbon distribution in Crypthecodinium sp. SUN. Results show that glucose favored cell growth and starch accumulation. Sodium acetate limited glucose utilization and starch accumulation but caused a significant increase in total fatty acid (TFA) accumulation and the DHA percentage. Thus, the DHA content in the S group was highest among three groups and reached a maximum (10.65% of DW) at 96 h that was 2.92-fold and 2.24-fold of that in the G and M groups, respectively. Comparative transcriptome analysis showed that rather than the expression of key genes in fatty acids biosynthesis, increased intracellular acetyl-CoA content appeared to be the key regulatory factor for TFA accumulation. Additionally, metabolome analysis showed that the accumulated DHA-rich metabolites of lipid biosynthesis might be the reason for the higher TFA content and DHA percentage of the S group. The present study provides valuable insights to guide further research in DHA production.

Head and eyes: Looking behavior in 12- to 24-month-old infants.

This study demonstrates evidence for a foundational process underlying active vision in older infants during object play. Using head-mounted eye-tracking and motion capture, looks to an object are shown to be tightly linked to and synchronous with a stilled head, regardless of the duration of gaze, for infants 12 to 24 months of age. Despite being a developmental period of rapid and marked changes in motor abilities, the dynamic coordination of head stabilization and sustained gaze to a visual target is developmentally invariant during the examined age range. The findings indicate that looking with an aligned head and eyes is a fundamental property of human vision and highlights the importance of studying looking behavior in freely moving perceivers in everyday contexts, opening new questions about the role of body movement in both typical and atypical development of visual attention.

Parents using live streaming video cameras to view infants in a regional NICU: Impacts upon bonding, anxiety and stress

BackgroundWhile live streaming from the NICU has entered standard care in some tertiary hospitals, few studies have been explored the impact of this technology upon parents. AimTo understand the impact of live-streaming vision of infants in NICU to their parents. MethodIn the present study, cameras were installed and parents live-streamed vision of their infants while admitted to a regional NICU. Camera usage data were recorded, and parent-infant bonding, parental stress and anxiety data were collected via online survey across four time points. ResultsWhile parents preferred to be with their infant in person, there was strong acceptance of the technology. There were no significant differences in camera usage across the admission and at 3-month follow-up. The relationships between camera usage and bonding, stress, and anxiety scores varied across time points and no significant changes in anxiety, stress and bonding scores were identified. ConclusionImplementation of this technology into standard care requires streaming stability and support for staff and parents to effectively use the technology.

Pre-constancy vision in infants

Pre-constancy vision in infants

The Historical Articles in Neuro-ophthalmology: Vision in Young Infants and Preferential Looking

The Historical Articles in Neuro-ophthalmology: Vision in Young Infants and Preferential Looking

Importance of omega 3 fatty acids in health

Omega 3 fatty acids are polyunsaturated fatty acids, essential since the human body does not produce them and they are obtained mainly from the diet. They confer flexibility, fluidity and selective permeability to the membranes, which favors cardiovascular health, reduces the risk of deficiencies in vision and neural development in infants and children, and dementia in older adults; some of them are precursors in the synthesis of prostaglandins. Some effects have also been seen in the prevention and treatment of coronary heart disease, hypertension, diabetes, arthritis, inflammation, autoimmune disorders, and cancer. These effects can be explained through the specific actions of each of them. Dietary fat influences the modulation of immune functions and inflammatory processes; most of the impact is attributed to long-chain polyunsaturated fatty acids (LCPUFA). The EPA exerts: hypotriglyceridemic effect at LDL and VLDL level; hypocholesterolemic effect due to increase in bile efflux and reverse cholesterol transport; antithrombotic effect due to the formation of Series 3 eicosanoids. DHA: increases the fluidity of neuronal, glial, and cone and rod membranes; decreases neuronal apoptosis; facilitates the recycling of neurotransmitters; regulates the expression of enzymes involved in lipid metabolism as a ligand for PPARs; inhibits insulin resistance to muscle and fat tissues. The intake recommendations are: 6 polyunsaturated fatty acids: 2.5-9% of energy intake/daily, and ω3 polyunsaturated fatty acids: 0.6-2.0% of energy intake/daily. Key words: omega-3 fatty acids; food sources; immune system; pathologies.

Earlier Intervention for Medically Fragile Pediatric Inpatient Population

Earlier Intervention for Medically Fragile Pediatric Inpatient Population

Development of stereo vision in young infants

In this study, infants' visual processing of depth-inducing stimuli was tested using a new method suitable for experimental settings. Stereograms of the Lang-Stereopad® were presented in a timed preferential-looking paradigm to determine infants' preference for a stereogram as compared to a stimulus not inducing an impression of depth. A total of 80 infants were tested at 7 months of age; of these, a sub-sample of 41 infants were tested longitudinally at 4 and 7months to characterize the developmental trajectory of their preference. Infants were simultaneously presented with a card showing a random-dot stereogram (800" disparity) and a similar looking dummy card without stereogram. In the total sample, 7-month-olds showed a clear preference for the stereogram regardless of sex. In the longitudinal sample, 7-month-olds but not 4-month-olds looked significantly longer to the stereogram as compared to the dummy card. On individual level, 56% of the 4-month-olds and 85% of the 7-month-olds predominantly looked at the stereogram. The findings yield evidence for a clear developmental progression and show that the test cards of the Lang-Stereopad® prototype provide a viable instrument to determine the preference for depth-inducing stimuli in young infants when used in a controlled experimental setting.

Running towards amblyopia recovery

Amblyopia is a neurodevelopmental disorder of the visual cortex arising from abnormal visual experience early in life which is a major cause of impaired vision in infants and young children (prevalence around 3.5%). Current treatments such as eye patching are ineffective in a large number of patients, especially when applied after the juvenile critical period. Physical exercise has been recently shown to enhance adult visual cortical plasticity and to promote visual acuity recovery. With the aim to understand the potentialities for translational applications, we investigated the effects of voluntary physical activity on recovery of depth perception in adult amblyopic rats with unrestricted binocular vision; visual acuity recovery was also assessed. We report that three weeks of voluntary physical activity (free running) induced a marked and long-lasting recovery of both depth perception and visual acuity. In the primary visual cortex, ocular dominance recovered both for excitatory and inhibitory cells and was linked to activation of a specific intracortical GABAergic circuit.

The mystery of the missing pit

Foveal hypoplasia refers to the underdevelopment of fovea, characterized by the continuity of the inner retinal layers in the presumed foveal area; the foveal avascular zone may be limited or absent, and retinal vessels may be seen coursing through the foveal region. It is usually associated with aniridia, albinism, achromatopsia, or retinopathy of prematurity. Isolated foveal hypoplasia is a rare clinical entity. We hereby report a case of congenital nystagmus with foveal hypoplasia. Fundus finding in isolated foveal hypoplasia though typical is very subtle and often difficult to detect, especially due to accompanying nystagmus. The presence of nystagmus and poor vision in infants or children without any ocular finding should prompt the ophthalmologist to carry out a thorough fundus examination of the foveal area and to perform an optical coherence tomography to confirm the diagnosis.

An Update of the Recent Developments on Amblyopia

Amblyopia is a neurodevelopmental disorder of the visual cortex arising from abnormal visual experience early in life. Amblyopia is a major cause of impaired vision in infants and young children (prevalence around 3.5%). There are different treatment options for amblyopia based on its severity and age of the patient. Traditional treatments include patching or occlusion of the dominant eye and pharmacological penalisation using Atropine (1%). Recent developments in amblyopia management have found success with the use of binocular exercises and certain modifications of glasses and contact lenses. The critical age up to which amblyopia is treatable or reversible is also being pushed up with more research. With newer advancements in amblyopia therapy, the success rate is also improving with multimodal approach.