The treatment of amblyopia: current practice and emerging trends

The outcomes of paediatric cataract surgery with intraocular lens insertion in sub-Saharan Africa: a systematic review

IMPORTANCE

Cataract is one of the leading causes of childhood blindness in Africa. The management of this condition requires timely surgical extraction of the cataractous lens with immediate optical correction and long-term follow-up to monitor visual improvement and manage complications that may arise. This review provides an opportunity to benchmark outcomes and to shed light on the reasons for those outcomes.

OBJECTIVES

To review the published literature and report on the outcomes of paediatric cataract surgery with intraocular lens insertion in sub-Saharan Africa.

DATA SOURCE

The EMBASE, PubMed, Scopus, and Web of Science were searched for relevant articles.

STUDY SELECTION

We included all published primary studies from sub-Saharan Africa on cataract surgery outcomes in children aged 0-16 years with primary intraocular lens implantation conducted between 1990 and 2020. Eligible studies were those published in English or for which an English translation was available. In addition, reviewers screened the reference lists of all studies included in the full-text review for eligible studies. During the review, studies fitting the inclusion criteria above except for having been conducted in middle and high-income countries were tagged and placed in a comparison arm.

DATA EXTRACTION AND SYNTHESIS

Study eligibility was determined by two independent reviewers, and data extraction was conducted by one reviewer with entries checked for accuracy by another reviewer. Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines for data synthesis were followed. The Joanna Briggs Institute (JBI) critical appraisal checklist was used for quality appraisal of the studies. The statistical software R was used in the analysis, and data were pooled using a random-effects model. Forest plots were generated using the R package 'metafor'.

MAIN OUTCOMES AND MEASURES

The primary outcome was visual acuity (VA) after cataract surgery and the proportions of eyes that achieved good, borderline, or poor visual outcome according to the World Health Organisation (WHO) categorisation of post-operative visual acuity. The secondary outcome measures reported included lag time to surgery, rates of follow-up, and rate of complications.

RESULTS

Eight out of 4763 studies were eligible for inclusion in this review, and seven were included in the quantitative analysis. There was a male preponderance in the study population, and the mean age at the time of cataract surgery ranged from 3.4 to 8.4 years. Visual outcomes were available for short-term visual outcomes (1 to 6 months) as the studies had a significant loss to follow-up. The pooled proportion of eyes that achieved a good visual acuity (i.e. equal to or greater than 6/18) in the short-term period was 31% (CI, 20-42). The comparative studies from middle and high-income countries reported proportions ranging from 41 to 91%, with higher thresholds for good visual acuity of 6/12 and 6/15.

CONCLUSION AND RELEVANCE

This review reports that there is a lower proportion of eyes with good outcomes after undergoing paediatric cataract surgery in sub-Saharan Africa than in middle- and high-income countries. Furthermore, this review states that there is a high proportion of patients lost to follow-up and suboptimal refractive correction and amblyopia treatment after paediatric cataract surgery.

The Impact of Optimized Blinking on Vision and Related Parameters in Individuals With Computer Vision Syndrome: A Single-Blind Randomized Controlled Trial

INTRODUCTION

Computer vision syndrome (CVS) has become a significant issue for individuals working on computers and digital devices for extended periods. The ocular and periocular symptoms and signs associated with CVS are a major concern, affecting individuals physically and financially. Additionally, CVS has been linked to the rapid progression of myopia, exacerbating the situation. Blinking has been one of the major treatment methods for the treatment of CVS. This study presents a unique and novel randomized controlled therapeutic trial that evaluates the impact of extended blinking therapy on eye health and vision, along with other related parameters. Materials and methods: The present study is a randomized controlled trial conducted from September 2022 to April 2024. Participants aged 18-40 with CVS and a computer vision syndrome questionnaire (CVS-Q) score of ≥6, with mild to moderate refractive error (between -6D and +4D), were included. The sample size was determined based on a pilot study, resulting in a minimum required sample size of 36 patients (18 cases and 18 controls). Participants were randomly assigned to either the case (interventional) or control (conventional) group and were followed up for six months. Cases received conventional CVS treatment plus optimized blinking exercises, while controls received conventional therapy only. Comprehensive ocular assessments were conducted bi-monthly over six months, evaluating changes in uncorrected visual acuity (UCVA), refractive error, near point of accommodation (NPA), near point of convergence (NPC), Schirmer's test, and tear film breakup time (TBUT).

RESULTS

The study included 20 patients in the case group and 18 in the control group, primarily aged 20-29 (60.5%). Most patients used laptops for their activities (55.26%). The CVS-Q score significantly decreased in both groups following treatment, with both cases and controls showing significant improvement (p<0.001 for both groups). UCVA in the right eye (RE) and left eye (LE) of the cases improved significantly post-treatment in the interventional group (RE: p=0.002; LE: p<0.001). A significant change in refractive error, which is measured as spherical equivalent (SE), was seen among cases following treatment (RE: p<0.001; LE: p=0.021). Controls showed no significant changes in visual acuity or refractive error. The NPA in the cases improved significantly in the RE (p=0.027) but not in the left. The NPC in the intervention group showed no significant change, while controls showed considerable improvement (p=0.042). Schirmer's test results showed no significant change in either group. However, TBUT in the cases improved significantly (RE: p<0.001; LE: p<0.001). In the controls, TBUT decreased significantly, indicating a deterioration in tear film stability. Asthenopia grades improved considerably in cases, while controls showed only some improvement. Severe symptoms still remained in the control group, emphasizing the potential benefits of the blinking exercise in reducing asthenopia symptoms.

CONCLUSION

Optimized blinking therapy significantly improves vision and refractive error, tear film stability, and discomfort, making it beneficial for chronic computer users to maintain ocular health and enhance productivity and quality of life.

Effectiveness of a Novel Video Game Platform in the Treatment of Pediatric Amblyopia

PURPOSE

To test the non-inferiority of a novel game platform for the treatment of pediatric amblyopia compared to standard eye patching.

METHODS

Forty participants (ages 4 to 18 years) across seven optometric clinics in the United States diagnosed as having amblyopia associated with anisometropia were randomly assigned to either 12 weeks of eye patching therapy (n = 19) or Barron Vision (Barron Associates, Inc) video game treatment (n = 21). Participants in the eye patching group with best corrected visual acuity (BCVA) worse than 20/200 in their amblyopic eye were prescribed 6 hours of patching daily, whereas those whose BCVA was 20/200 (1.00 logarithm of the minimum angle of resolution [logMAR]) or better were instructed to patch for 2 hours daily. Participants in the video game group, irrespective of the severity of their amblyopia, were instructed to play four different 5-minute mini-games five times a week for a total of 20 minutes a day.

RESULTS

A mixed linear modeling analysis of before and after BCVA differences after 12 weeks showed the non-inferiority of video game treatment to eye patching using a 0.10 logMAR threshold while adjusting for the participant's age, sex, and baseline BCVA.

CONCLUSIONS

The results of the study suggest that a 12-week home-based video game vision therapy intervention can provide equivalent treatment outcomes to eye patching for amblyopia in children ages 5 to 18 years. Video game-based vision therapy may be a more acceptable and time-efficient alternative to existing approaches. By incorporating elements of perceptual learning, approaches such as Barron Vision video game treatment may have additional long-term therapeutic benefits and may improve treatment compliance. [J Pediatr Ophthalmol Strabismus. 2024;61(1):20-29.].

Digital Therapy for Visual Acuity and Binocular Function in Children with Anisometropic Amblyopia

Amblyopia affects development of children's monocular vision and binocular function and becomes a largely intractable problem with increasing aging. This study is to investigate the binocular function and evaluate efficacy of digital therapy in children 8-13 years of age with anisometropic amblyopia. The patients in the digital therapy group performed the training with the digital amblyopia therapeutic software. The visual acuity and binocular function (perceptual eye position [PEP], suppression, and stereopsis) were examined at the first visit and 3-month post-treatment. Twenty-three cases in the control group and 25 cases in the digital therapy group were enrolled. The results revealed that 3-month digital therapy can effectively improve corrected distance visual acuity (CDVA) and improve the binocular function, including PEP, suppression, and second-order stereopsis in children with anisometropic amblyopia, 8-13 years of age. Digital therapy for amblyopia can effectively improve monocular CDVA of amblyopic eyes and binocular function in older children with anisometropic amblyopia.

Qualitative Exploration of the Visual Function Impairments and Health-Related Quality of Life Impacts of Amblyopia in Adult and Pediatric Populations

INTRODUCTION

Amblyopia is a reduction in vision in one or both eyes due to impaired development of the visual pathway. This study explored the experience of amblyopia and treatment from the patient, caregiver, and clinician perspectives.

METHODS

A targeted literature review, including a review of social media listening (SML) studies, was conducted. Next, qualitative interviews were conducted with amblyopia patients, caregivers of children with amblyopia, and ophthalmologists with experience treating patients with amblyopia. The findings informed the development of a disease model. Amblyopia clinical experts provided input at key stages.

RESULTS

Twelve data sources were reviewed, including qualitative studies in the literature and SML studies. Overall, 133 patients/caregivers were interviewed (23 adults, 16 adolescents, 47 child-caregiver dyads), plus 10 ophthalmologists from the United States, France, and Germany. Reduced visual acuity, impaired depth perception, impaired peripheral vision, and double vision were the most frequently reported symptoms. Amblyopia impacted daily activities (reading, using digital devices), the ability to move around, school/work (productivity, seeing the board in class), emotional well-being (frustration, sadness), and social functioning (difficulty socializing). Treatments, including patching and corrective lens, also impacted daily activities (using digital devices, sports/leisure), mobility (bumping into things), and work/school (tasks taking longer) as well as emotional well-being (embarrassment), and social functioning (bullying/stigma).

CONCLUSION

The findings contribute valuable insights into the adult and pediatric experience of amblyopia from a multi-stakeholder perspective. The findings were used to critically assess existing clinical outcome assessments and supported the development of patient- and observer-reported outcome measures for use in amblyopia clinical trials.

Factors affecting the benefit of glasses alone in treating childhood amblyopia: an analysis of PEDIG data

BACKGROUND

To evaluate factors associated with better outcomes from optical treatment alone in amblyopic children from 3 up to 7 years.

METHODS

Data extracted from two studies with similar protocols, Amblyopic Treatment Studies 5 (n = 152) and 13 (n = 128) from the Pediatric Eye Disease Investigator Group database, were used to determine by regression analysis the factors associated with improvements in visual acuity in the amblyopic eye, inter-ocular visual acuity difference and stereoacuity. Input variables were aetiology of amblyopia (anisometropic, strabismic and combined-mechanism amblyopia), treatment compliance, visual acuity, interocular visual acuity difference, stereoacuity, tropia size at distance and near, age and refractive error at baseline.

RESULTS

Despite the range of clinical factors considered, our models explain only a modest proportion of the variance in optical treatment outcomes. The better predictors of the degree of optical treatment success in amblyopic children are visual acuity of the amblyopic eye, interocular visual acuity difference, stereoacuity, treatment compliance and the amblyopic eye spherical-equivalent refractive error. While the aetiology of the amblyopia does not exert a major influence upon treatment outcome, combined-mechanism amblyopes experience the smallest improvement in visual acuity, tropia and stereoacuity and may need longer optical treatment periods.

CONCLUSIONS

While results identify the factors influencing optical treatment outcome in amblyopic children, clinicians will be unable to predict accurately the benefits of optical treatment in individual patients. Whether this is because relevant clinical or non-clinical factors (e.g. nature and volume of daily activities undertaken) influences the outcomes from optical treatment has not yet been identified and remains to be discovered.

Analysis of the improvement in monocular amblyopia visual acuity caused by the changes in non-amblyopia visual acuity in 74 adults

To observe the clinical phenomenon of amblyopia vision improvement in patients with monocular amblyopia over 18 years old after non-amblyopia diseases, analyze the conditions and causes of vision improvement, explore the plasticity of the adult optic nerve, and provide a clinical basis for the treatment of adult amblyopia. A total of 74 patients with monocular amblyopia combined with non-amblyopia visual acuity decline from 2018 to 2021 were collected. The patient's age, initial best-corrected visual acuity (BCVA), pattern visual evoked potential examination results, and visual acuity regression were recorded. The BCVA of amblyopia was recorded every 3 months using an early treatment of diabetic retinopathy study visual acuity chart. In the 3rd month, BCVA increased by 16.2%, reaching 98% in the 9th month and 100% in the 12th months. According to the age of patients, the group aged 18 to 35 years was better than the group aged 35 to 60 years, whereas the group aged 35 to 60 years was better than the group aged over 60 years (P < .05). According to the comparison of initial visual acuity, the BCVA of the < 5 letter group was lower than that of the other 2 groups (P < .05). According to the pattern visual evoked potential results, the peak time of the < 10 ms group was better than that of the 10 to 20 ms group; the 10 to 20 ms group was better than that of the > 20 ms group; the peak decrease of the < 30% group was better than that of the 30% to 50% group; and the 30% to 50% group was better than that of the > 50% group (P < .05). The visual acuity regression of amblyopia in the 0.5 to 1-year group was higher than that in the other 2 groups (P < .05). This study confirms that adult amblyopia can still be cured under certain conditions. This visual plasticity is related to age, initial visual acuity, and excitability of the visual center. This study provides new clinical evidence and diagnostic ideas for the study of the pathogenesis of adult amblyopia.

The Amblyopia Quality of Life (AmbQoL): Development and Content Validation of a Novel Health-Related Quality of Life Instrument for Use in Adult and Pediatric Amblyopia Populations

INTRODUCTION

Amblyopia is a neurodevelopmental vision disorder, characterized by poor vision in one or both eyes. Given the lack of existing clinical outcome assessments (COA) considered fit-for-purpose for amblyopia clinical trials, this study developed new COAs to assess amblyopia symptoms and health-related quality of life (HRQoL) impacts in adult and pediatric amblyopia populations that conform with best practice standards and regulatory guidelines.

METHODS

Findings from a targeted qualitative literature review informed the development of three versions of the new Amblyopia Quality of Life Questionnaire (AmbQoL): a patient-reported outcome measure (PRO) for individuals aged 13 years and older, a PRO for children aged 9-12 years, and an observer-reported outcome measure (ObsRO) for caregivers of children aged 4-8 years. Qualitative interviews were conducted with the target populations, and with ophthalmologists experienced in treating amblyopia patients to evaluate the content validity for further development of the AmbQoL. A translatability assessment was conducted to ensure cultural appropriateness and usability across multiple languages. Feedback from Food and Drug Administration (FDA) was also sought on the instruments, and clinical experts provided input at key stages.

RESULTS

Interviews were conducted with 112 patients/caregivers and ten ophthalmologists from the USA, France, and Germany. The instructions, items, and response options were well understood across all AmbQoL versions. Feedback from the patients, caregivers, ophthalmologists, the translatability assessment, the FDA, and the expert clinicians informed minor wording modifications to enhance clarity and translatability. Some items were removed due to low relevance. The study resulted in a 23-item adult/adolescent PRO, 24-item child PRO, and 12-item ObsRO, each employing a 7-day recall period.

CONCLUSION

Each AmbQoL version has documented support for its face and content validity for use in amblyopia populations aged ≥ 4 years. Further research is necessary to evaluate the psychometric measurement properties of the AmbQoL instruments to enable their use in amblyopia treatment trials.

Design and assessment of amblyopia, strabismus, and myopia treatment and vision training using virtual reality

Background

Virtual reality is a relatively new intervention that has the potential to be used in the treatment of eye and vision problems. This article reviews the use of virtual reality-related interventions in amblyopia, strabismus, and myopia research.

Methods

Sources covered in the review included 48 peer-reviewed research published between January 2000 and January 2023 from five electronic databases (ACM Digital Library, IEEE Xplore, PubMed, ScienceDirect and Web of Science). To prevent any missing relevant articles, the keywords, and terms used in the search included "VR", "virtual reality", "amblyopia", "strabismus," and "myopia". Quality assessment and data extraction were performed independently by two authors to form a narrative synthesis to summarize findings from the included research.

Results

Total number of 48 references were reviewed. There were 31 studies published on amblyopia, 18 on strabismus, and 6 on myopia, with 7 studies overlapping amblyopia and strabismus. In terms of technology, smartphone-based virtual reality headset viewers were utilized more often in amblyopia research, but commercial standalone virtual reality headsets were used more frequently in myopia and strabismus-related research. The software and virtual environment were mostly developed based on vision therapy and dichoptic training paradigms.

Conclusion

It has been suggested that virtual reality technology offers a potentially effective tool for amblyopia, strabismus, and myopia studies. Nonetheless, a variety of factors, especially the virtual environment and systems employed in the data presented, must be explored before determining whether virtual reality can be effectively applied in clinical settings. This review is significant as the technology in virtual reality software and application design features have been investigated and considered for future reference.

Learning to see in depth

Stereopsis provides us with a vivid impression of the depth and distance of objects in our 3- dimensional world. Stereopsis is important for a number of everyday visual tasks, including (but not limited to) reaching and grasping, fine visuo-motor control, and navigating in our world. This review briefly discusses the neural substrate for normal binocular vision and stereopsis and its development in primates; outlines some of the issues and limitations of stereopsis tests and examines some of the factors that limit the typical development of stereopsis and the causes and consequences of stereo-deficiency and stereo-blindness. Finally, we review several approaches to improving or recovering stereopsis in both neurotypical individuals and those with stereo-deficiency and stereo-blindness and outline some emerging strategies for improving stereopsis.

Comparison of compliance among patients with pediatric amblyopia undergoing virtual reality-based and traditional patching method training

Introduction

This study aimed to compare compliance between pediatric patients with amblyopia undergoing a smartphone virtual reality-based training method (EYEBIT) and those receiving traditional patching method training.

Methods

A crossover design was adopted in this study. The enrolled children (n = 76) were randomized into the traditional patching and EYEBIT training method groups. The patients received training methods once a day for 2 h and 1 h in the patching and EYEBIT groups, respectively. Follow-up assessments involved interviews with parents regarding children's compliance and questionnaire-based interviews with children; compliance rating was compared between the methods.

Results

All children completed the training and follow-up assessments. There were significant differences in parent and children compliance-related behavior and attitudes between the two training methods (p < 0.05). The EYEBIT method was associated with better compliance than the traditional patching method. Significant correlations were observed among compliance components in both methods. In the correlation analysis between the two groups, the research results showed that in the EYEBIT group, the correlation between children's compliance behaviors and children's compliance attitudes, the correlation between children's compliance behaviors and parents' compliance behaviors, and the correlations between children's compliance attitudes and parents' compliance attitudes were all negatively correlated, and in the traditional patching group, the above three correlation analysis results were all positive.

Conclusion

The use of the EYEBIT method may improve compliance in children with amblyopia; this method appears acceptable to the parents of children with amblyopia.

The 100 most cited papers on amblyopia: a bibliographic perspective

AIM

To analyze the top 100 most cited papers related to amblyopia.

METHODS

A bibliographic search in the Institute for Scientific Information Web of Knowledge across 55 years was performed.

RESULTS

Eighty-nine of the 100 papers were published in first-quartile journals. Half (50) of the senior authors were from the USA. Most papers dealt with clinical science (72) and included original research (84). Forty-two of the articles related to all three types of amblyopia (refractive, strabismic and deprivation). Thirty-four related to both strabismic and refractive amblyopia. Around two-thirds of the papers dealt with treatment (34) and pathophysiology (30). Almost a quarter (23%) of the papers were multicenter studies. Nearly half (48) of the papers were published between 2000 and 2010. The Pediatric Eye Disease Investigator Group (PEDIG) published the highest number of studies (11), which dealt more with treatment (p = 0.01) and had higher average number of citations per years (p = 0.05). A larger number of articles on the treatment of amblyopia are newer (p = 0.01). There was no correlation between the time of their publication and the number of citations (p = 0.68, r = 0.042).

CONCLUSIONS

Half of the papers were published between 2000 and 2010 and were spearheaded by PEDIG. Most papers dealt with treatment and pathophysiology. This study provides an important historical perspective, emphasizing the need for additional research to better understand this preventable and curable childhood vision impairment.

Treatment compliance in amblyopia: A mini-review and description of a novel online platform for compliance tracking

Patient compliance with amblyopia therapies, including eye patching and atropine drops, is crucial for optimal visual acuity outcomes. Studies utilizing objective measures of compliance measurement have consistently shown that a majority of patients receive significantly less treatment than prescribed. We review the subjective and objective compliance rates reported in the literature, assess possible explanations for poor compliance and describe studies of interventions to improve compliance. Additionally, we report our experience implementing Inside Out Care, a novel online platform designed to improve monitoring of amblyopia patient compliance, in our clinics. We have found that this platform, which is accessible via both computer and smartphone, has improved monitoring of amblyopia patient patching compliance, as well as allowed for enhanced doctor-patient communication.

Regional Downregulation of Dopamine Receptor D1 in Bilateral Dorsal Lateral Geniculate Nucleus of Monocular Form-Deprived Amblyopia Models

Amblyopia is a common eye disease characterized by impaired best-corrected visual acuity. It starts in early childhood and leads to permanent vision reduction if left untreated. Even though many young patients with amblyopia are well treated in clinical practice, the underlying mechanism remains to be elucidated, which limits not only our understanding of this disease but also the therapeutic approach. To investigate the molecular mechanism of amblyopia, primate and rodent models of monocular-deprived amblyopia were created for mRNA screening and confirmation. We obtained 818 differentially expressed genes from the dorsal lateral geniculate nucleus (dLGN) of a primate model of amblyopia. After Gene Ontology and kyoto encyclopedia of genes and genomes (KEGG) enrichment analyses, the main enriched pathways were related to neural development. Interestingly, a particular neurotransmitter pathway, the dopaminergic pathway, was identified. The downregulation of dopamine receptor D1 (DRD1) was confirmed in both monkey and mouse samples. Furthermore, the immunofluorescence staining indicated that DRD1 expression was downregulated in both ventrolateral region of the contralateral dLGN and the dorsomedial region of the ipsilateral dLGN in the mouse model. The regions with downregulated expression of DRD1 were the downstream targets of the visual projection from the amblyopic eye. This study suggested that the downregulation of DRD1 in the LGN may be a cause for amblyopia. This may also be a reason for the failure of some clinical cases of levodopa combined with carbidopa applied to amblyopes.

Fixation instability, astigmatism, and lack of stereopsis as factors impeding recovery of binocular balance in amblyopia following binocular therapy

Dichoptic therapy is a promising method for improving vision in pediatric and adult patients with amblyopia. However, a systematic understanding about changes in specific visual functions and substantial variation of effect among patients is lacking. Utilizing a novel stereoscopic augmented-reality based training program, 24 pediatric and 18 adult patients were trained for 20 h along a three-month time course with a one-month post-training follow-up for pediatric patients. Changes in stereopsis, distance and near visual acuity, and contrast sensitivity for amblyopic and fellow eyes were measured, and interocular differences were analyzed. To reveal what contributes to successful dichoptic therapy, ANCOVA models were used to analyze progress, considering clinical baseline parameters as covariates that are potential requirements for amblyopic recovery. Significant and lasting improvements have been achieved in stereoacuity, interocular near visual acuity, and interocular contrast sensitivity. Importantly, astigmatism, fixation instability, and lack of stereopsis were major limiting factors for visual acuity, stereoacuity, and contrast sensitivity recovery, respectively. The results demonstrate the feasibility of treatment-efficacy prediction in certain aspects of dichoptic amblyopia therapy. Furthermore, our findings may aid in developing personalized therapeutic protocols, capable of considering individual clinical status, to help clinicians in tailoring therapy to patient profiles for better outcome.

Enhancement of visual perception by combining transcranial electrical stimulation and visual perceptual training

The visual system remains highly malleable even after its maturity or impairment. Our visual function can be enhanced through many ways, such as transcranial electrical stimulation (tES) and visual perceptual learning (VPL). TES can change visual function rapidly, but its modulation effect is short-lived and unstable. By contrast, VPL can lead to a substantial and long-lasting improvement in visual function, but extensive training is typically required. Theoretically, visual function could be further improved in a shorter time frame by combining tES and VPL than by solely using tES or VPL. Vision enhancement by combining these two methods concurrently is both theoretically and practically significant. In this review, we firstly introduced the basic concept and possible mechanisms of VPL and tES; then we reviewed the current research progress of visual enhancement using the combination of two methods in both general and clinical population; finally, we discussed the limitations and future directions in this field. Our review provides a guide for future research and application of vision enhancement and restoration by combining VPL and tES.

EEG Measurement for Suppression in Refractive Amblyopia and Push-pull Perception Efficacy

In order to evaluate refractive amblyopia suppression and understand the neural mechanism of amblyopia suppression and push-pull perception training, we recorded the EEG of refractive amblyopia children before, during, and after push-pull perception training. We compared the brain activity in different states through the steady-state visual evoked potentials (SSVEPs) response and power topography and compared them with normal children. We found that amblyopic and fellow eyes have different performances in fundamental and harmonic frequency responses. They also show different characteristics when be masked. Push-pull perception training improved the SSVEP performance of amblyopia children by reducing the SSVEP response difference between eyes and improving the intermodulation frequency response. The result of topography showed that push-pull perception reduced the alpha power of occipital and temporal lobes, which was conducive to improving binocular function. The changes of intermodulation response and occipital alpha power were significantly correlated with the clinical indicator. Thus, EEG is a potential method to measure amblyopia suppression and the efficacy of push-pull perception.

Stereopsis Only: Validation of a Monocular Depth Cues Reduced Gamified Virtual Reality with Reaction Time Measurement

The visual depth perception is composed of monocular and binocular depth cues. Studies show that in absence of binocular depth cues the performance of visuomotor tasks like pointing to or grasping objects is limited. Thus, binocular depth cues are of great importance for motor control required in everyday life. However, binocular depth cues like retinal disparity (basis for stereopsis) might be influenced due to developmental disorders of the visual system. For example, amblyopia in which one eye's visual input is not processed leads to loss of stereopsis. The primary amblyopia treatment is occlusion of the healthy eye to force the amblyopic eye to train. However, improvements in stereopsis are poor. Therefore, binocular treatments arose that equilibrate both eyes' visual input to enable binocular vision. However, most approaches rely on divided stimuli which do not account for loss of stereopsis. We created a Virtual Reality (VR) with reduced monocular depth cues in which a stereoscopic task is shown to both eyes simultaneously, consisting of two balls jumping towards the user. One ball appears closer to the user which must be identified. To evaluate the task performance the reaction time is measured. We validated our approach with 18 participants with stereopsis under three contrast settings including one leading to monocular vision. The number of correct responses reduces from 90% under binocular vision to 52% under monocular vision corresponding to random guessing. Our results indicate that it is possible to disable monocular depth cues and create a dynamic stereoscopic task inside a VR.

Treatment Outcome of Occlusion for Unilateral Amblyopia in Saudi Children 6-12 Years Old

PURPOSE

The purpose of this study was to estimate the rate and review determinants of successful therapy for unilateral amblyopia in children.

METHODS

This prospective cohort consisted of Saudi children aged 6-12 who received amblyopia therapy between 2020 and 2022. Best-corrected visual acuity (BCVA) in the amblyopic eye improved to reach the BCVA of the fellow eye at follow-up visits, or BCVA in the amblyopic eye improved and remained stable over three follow-up visits. Demographic and ocular characteristics were associated with the outcome.

RESULTS

In 30 children, the median BCVA at presentation and the last follow-up was 0.8 logMAR (interquartile range [IQR]: 0.6; 1.0) and 0.45 logMAR (IQR: 0.3; 0.6), respectively. The success rate of amblyopia therapy was 80% (95% confidence interval: 65.7; 94.3). It was 100%, 76.5%, and 77.8% in eyes with anisometropic, strabismic, and mixed types of amblyopia, respectively. Amblyopia grade (P = 0.177), type of amblyopia (P = 0.96), and spectacles as therapy in the past (P = 0.09) were not significantly associated with the successful out. The duration of follow-up was significantly longer in those with unsuccessful outcomes (P = 0.05). Excellent compliance for occlusion was observed in 62.5% of children with successful outcomes. In 14 (46.7%) children, BCVA was ≤0.3 logMAR BCVA at the last follow-up. Two-line improvement in amblyopic eyes was in 26 (86.7%) children at the last follow-up compared to BCVA at presentation.

CONCLUSION

Occlusion therapy complemented using glasses in older children also significantly improved visual recovery in amblyopic eyes.

Comparison of horizontal muscle transposition and Inferior oblique weakening combined with horizontal surgery in V-pattern exotropia

Purpose

The objective of this study was to compare the effects of horizontal muscle transposition and inferior oblique weakening combined with horizontal surgery performed for V-pattern exotropia (XT) and to determine the most successful approach.

Methods

In our retrospective study, 52 patients who underwent horizontal surgery due to V-pattern XT and were followed up for at least 6 months were divided into two groups. Group 1 (n = 26) consisted of patients who underwent vertical transposition of the rectus muscles combined with horizontal surgery, and group 2 (n = 26) consisted of patients who underwent inferior oblique weakening combined with horizontal surgery. The two groups were compared before and after surgery in terms of visual acuity, refractive errors, deviation angles, pattern strabismus, fusion, stereopsis, over/under correction and surgical success.

Results

There was no difference between the two groups in terms of age, follow-up period, visual acuity, refractive errors, fusion or stereopsis. The amount of horizontal deviation was smaller in group 2 at the 1-6-month follow-ups. There was no difference between the two groups in terms of pattern collapse; however, the amount of pattern postoperatively was lower in group 2. The two groups were similar in terms of overcorrection; however, the undercorrection rate was higher in group 1. The surgical success rate was higher in group 2.

Conclusions

Inferior oblique weakening combined with horizontal surgery due to V-pattern XT was found to be superior to vertical transposition of the horizontal muscles in terms of surgical success and the amount of pattern postoperatively.

New treatment for amblyopia based on rules of synaptic plasticity: a randomized clinical trial

Amblyopia resulting from early deprivation of vision or defocus in one eye reflects an imbalance of input from the eyes to the visual cortex. We tested the hypothesis that asynchronous stimulation of the two eyes might induce synaptic plasticity and rebalance input. Experiments on normal adults showed that repetitive brief exposure of grating stimuli, with the onset of each stimulus delayed by 8.3 ms in one eye, results in a shift in perceptual eye dominance. Clinical studies (Clinical trial registration number: ChiCTR2100049130), using popular 3D movies with similar asynchrony between the two eyes (amblyopic eye stimulated first) to treat anisometropic amblyopia, established that just 10.5 h of conditioning over <3 weeks produced improvement that met criteria for successful treatment. The benefits of asynchronous conditioning accumulate over 20-30 45 min sessions, and are maintained for at least 2 years. Finally, we demonstrate that asynchronous binocular treatment alone is more effective than patching only. This novel treatment is popular with children and is some 50 times more efficient than patching alone.

A Randomized Trial of Binocular Dig Rush Game Treatment for Amblyopia in Children Aged 4 to 6 Years

SIGNIFICANCE

Binocular treatment for unilateral amblyopia is an emerging treatment that requires evaluation through a randomized clinical trial.

PURPOSE

This study aimed to compare change in amblyopic-eye visual acuity (VA) in children aged 4 to 6 years treated with the dichoptic binocular iPad (Apple, Cupertino, CA) game, Dig Rush (not yet commercially available; Ubisoft, Montreal, Canada), plus continued spectacle correction versus continued spectacle correction alone.

METHODS

Children (mean age, 5.7 years) were randomly assigned to home treatment for 8 weeks with the iPad game (prescribed 1 h/d, 5 d/wk [n = 92], or continued spectacle correction alone [n = 90]) in a multicenter randomized clinical trial. Before enrollment, children wearing spectacles were required to have at least 16 weeks of wear or no improvement in amblyopic-eye VA (<0.1 logMAR) for at least 8 weeks. Outcome was change in amblyopic-eye VA from baseline to 4 weeks (primary) and 8 weeks (secondary) assessed by masked examiner.

RESULTS

A total of 182 children with anisometropic (63%), strabismic (16%; <5∆ near, simultaneous prism and cover test), or combined-mechanism (20%) amblyopia (20/40 to 20/200; mean, 20/63) were enrolled. After 4 weeks, mean amblyopic VA improved by 1.1 logMAR lines with binocular treatment and 0.6 logMAR lines with spectacles alone (adjusted difference, 0.5 lines; 95.1% confidence interval [CI], 0.1 to 0.9). After 8 weeks, results (binocular treatment: mean amblyopic-eye VA improvement, 1.3 vs. 1.0 logMAR lines with spectacles alone; adjusted difference, 0.3 lines; 98.4% CI, -0.2 to 0.8 lines) were inconclusive because the CI included both zero and the pre-defined difference in mean VA change of 0.75 logMAR lines.

CONCLUSIONS

In 4- to 6-year-old children with amblyopia, binocular Dig Rush treatment resulted in greater improvement in amblyopic-eye VA for 4 weeks but not 8 weeks. Future work is required to determine if modifications to the contrast increment algorithm or other aspects of the game or its implementation could enhance the treatment effect.

Effects of Vision Therapy on Bilateral Amblyopia Unresponsive to Conventional Treatment: A Retrospective Comparative Study

Background: In this study we aim to determines the effect of our vision therapy program for 7- to 10-year-old patients who exhibit bilateral amblyopia that is no longer responsive to conventional treatment. Methods: Children with bilateral amblyopia between the ages of 7 and 10 treated with vision therapy at the China Medical University Hospital between 2016 and 2019 were retrospectively reviewed. Age and visual acuity-matched bilateral amblyopes are included as a control group. The visual acuity for both groups showed no improvement for more than 3 months with part-time patching and full refraction correction. The initial and final visual acuity, stereopsis, and refractive status were analyzed. Results: Here, 15 cases were included as the treatment group and 16 cases as a control group. At the endpoint, the study group shows a significant improvement in BCVA, with a mean of 0.32 ± 0.15 logMAR (3 lines improvement) versus 0.003 ± 0.19 logMAR (nearly no improvement) for the control group (p < 0.001). The benefits of treatment are most obvious in the first 3 months after treatment (p < 0.001) and last until the end point. Stereoacuity also improves from 190.00 ± 163.34 to 85.00 ± 61.24 arc seconds, which is a 55.26% improvement. Conclusions: Vision therapy, comprising orthoptic therapy, perceptual learning and dichoptic training, is a successful program for increasing visual acuity and stereoacuity in 7- to 10-year-old children with bilateral amblyopia that is unresponsive to conventional treatment.

An updated review about perceptual learning as a treatment for amblyopia

The purpose of our work is to do an update of recent investigations about amblyopia treatment based on perceptual learning, dichoptic training and videogames. Therefore, we conducted a search of the studies published about this subject in the last six years. The review shows that the investigations during that period have used several kinds of treatments regarding their design (e.g., type of stimulus and context used, duration of the training), and in a wider range of age that also include adults. Most of the studies have found an improvement in some mono and binocular visual functions, such as visual acuity, contrast sensitivity and stereopsis, which for now, it seems advisable that these processes could be used, as an alternative or a complement of the traditional passive therapy. Nevertheless, it would be plausible to conduct additional, controlled and random, clinical trials in order to discover in a more deeply way which perceptive learning method of treatment is more effective for the improvement of visual functions and for how long the effects of the treatment could persist.

Expression of early growth responsive gene-1 in the visual cortex of monocular form deprivation amblyopic kittens

PURPOSE

The present study compared the expression of early growth responsive gene-1 (Egr-1) in visual cortex between amblyopia kittens and normal kittens, and to explore the role of Egr-1 in the pathogenesis of amblyopia.

METHODS

A total of 20 healthy kittens were randomly divided into deprivation group and control group with 10 kittens in each group. Raised in natural light, and covered the right eye of the deprived kittens with a black opaque covering cloth. Pattern visual evoked potentials (PVEP) were measured before and at the 1st, 3rd and 5th week after covering in all kittens. After the last PVEP test, all kittens were killed. The expression of Egr-1 in the visual cortex of the two groups was compared by immunohistochemistry and in situ hybridization.

RESULTS

PVEP detection showed that at the age of 6 and 8 weeks, the P100 wave latency in the right eye of deprivation group was higher than that in the left eye of deprivation group (P < 0.05) and the right eye of control group (P < 0.05), while the amplitude decreased (P < 0.05). The number of positive cells (P < 0.05) and mean optical density (P < 0.05) of Egr-1 protein expression in visual cortex of 8-week-old deprivation group were lower than those of normal group, as well as the number (P < 0.05) and mean optical density of Egr-1 mRNA-positive cells (P < 0.05).

CONCLUSIONS

Monocular form deprivation amblyopia can lead to the decrease of Egr-1 protein and mRNA expression in visual cortex, and then promote the occurrence and development of amblyopia.

Comparison of binocular game and patching in treating mild to moderate anisometropic amblyopia: a study protocol for a randomized controlled trial

BACKGROUND

Amblyopia, as a neurodevelopmental preventable visual disorder, affects approximately 1.1 % in Asia. A binocular approach to treating amblyopia has been recently proposed. Whether the binocular playing game treatment is comparable to patching treatment needs further randomized clinical trials. To address this, the present research, designs, develops, and evaluates a new binocular game to treat amblyopia.

METHODS

This study has been designed as a non-inferiority, randomized, two parallel-group, controlled trial. Forty-four patients between 4 and 12 years diagnosed with amblyopia will be randomly assigned to the control and intervention groups. In the intervention group, amblyopia treatment is provided with red-green anaglyphic glasses and a red filter placed in front of the amblyopic eye, along with a game to be played for 30 min twice a day. Those in the control group will receive patch therapy according to amblyopia treatment study protocol. The primary outcome is to change visual acuity in the amblyopic eye from the baseline to 3 months after randomization.

ETHICS AND DISSEMINATION

The Ethics Committee of Mashhad University of Medical sciences' approval date was February 28, 2018, with a reference code of IR.MUMS.fm.REC.1396.783. Thus far, the recruitment of participants has not been completed and is scheduled to end in September 2021. The results will be disseminated in a peer-reviewed journal.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials IRCT20180217038768N1 . Registered on 22 April 2019.

Identifying Characteristics Predictive of Lost-to-Follow-Up Status in Amblyopia

PURPOSE

To identify demographic and disease-related characteristics predictive of Lost-to-Follow-Up (LTFU) status in amblyopia treatment and create a risk model for predicting LTFU status.

DESIGN

Retrospective cohort study METHODS: Setting: Single-center, ophthalmology department at Boston Children's Hospital (BCH).

PATIENTS

2037 patients treated for amblyopia at BCH between 2010 and 2014.

OBSERVATION PROCEDURE

LTFU was defined as patients who did not return after initial visit, excluding those who came for second opinion. Multiple variables were tested for association with LTFU status.

OUTCOME MEASURE

Odds ratio of LTFU risk associated with each variable. Multivariate logistic regression was used to create a risk score for predicting LTFU status.

RESULTS

A large proportion of patients (23%) were LTFU after first visit. Older age, nonwhite race, lack of insurance, previous glasses or atropine treatment, and longer requested follow-up intervals were independent predictors of LTFU status. A multivariable risk score was created to predict probability of LTFU (area under the curve 0.68).

CONCLUSIONS

Our comprehensive amblyopia database allows us to predict which patients are more likely to be LTFU after baseline visit and develop strategies to mitigate these effects. These findings may help with practice efficiency and improve patient outcomes in the future by transitioning these analyses to an electronic medical record that could be programmed to provide continually updated decision support for individual patients based on large data sets.

Pediatric spectacle prescription: Understanding practice patterns among ophthalmologists and optometrists in Saudi Arabia

PURPOSE

This study aims to understand the approach to prescribing spectacles for children and the interpretation of refractive errors among ophthalmologists/optometrists in Saudi Arabia.

METHODS

A cross-sectional survey was conducted between September and November 2018 using a database of online registrants for ophthalmologists and optometrists practicing in Saudi Arabia. The survey included 10 multiple-choice questions designed to elicit information about how ophthalmologists and optometrists deal with commonly encountered case scenarios covering different practical aspects of pediatric refraction. The responses were compared using the proportion of pediatric clientele received in the respondents' practices (Group A: <25%, Group B: 25%) and drawing upon concepts from the published literature.

RESULTS

One hundred and three participants, including ophthalmologists, specialists/registrars, and optometrists from across Saudi Arabia, participated in this survey. Approximately 25% were classified as Group A. Large discrepancies were observed between the participants' responses and actual practices based on guideline recommendations. Responses varied significantly between Groups A and B on certain issues pertaining to pseudomyopia (P < 0.001), anisometropia (P = 0.033), and high astigmatism (P = 0.023).

CONCLUSION

Practice patterns regarding pediatric spectacle prescription varied among ophthalmologists and optometrists in Saudi Arabia. The approach to managing refractive errors in children was better among ophthalmologists/optometrists servicing a larger pediatric clientele, suggesting the need to increase awareness among all groups of ophthalmologists/optometrists.

The Assessment of YouTube Videos as a Source of Information for Amblyopia Treatment

PURPOSE

To evaluate the efficiency of YouTube videos as a source of information for the treatment of amblyopia.

METHODS

The authors searched YouTube (Google) using the keywords "amblyopia treatment" and analyzed the first 200 most relevant videos. Videos were classified as useful or misleading by two independent ophthalmologists. Videos were scored on 5-point scales to evaluate global quality, reliability, and comprehensiveness. General characteristics, viewer interactions, and sources of videos were also recorded.

RESULTS

Eighty-seven of 200 videos were appropriate to be included in the current study. Fifty videos (57.5%) were classified as useful and 37 videos (42.5%) were classified as misleading. General characteristics and viewer interactions were not significantly different between useful and misleading videos (P > .05). The mean Global Quality Score, reliability, and comprehensiveness scores were 3.64 ± 1.1, 3.02 ± 1.0, and 2.74 ± 1.2 in useful videos and 2.03 ± 0.9, 2.08 ± 0.8, and 1.62 ± 0.7 in misleading videos, respectively (P < .05). The data suggested that most of the videos uploaded by university channels or non-profit professionals were useful (79.2%), whereas most of the videos uploaded by medical advertisements or for-profit companies were misleading (59.1%).

CONCLUSIONS

The results of the current cross-sectional study demonstrated that the number of useful videos for the treatment of amblyopia was higher on YouTube. However, there was still a significant number of misleading videos (42.5%). Therefore, more videos on amblyopia treatment that have sufficient reliability, quality, and comprehensiveness should be uploaded to YouTube. [J Pediatr Ophthalmol Strabismus. 2021;58(5):311-318.].

The development of active binocular vision under normal and alternate rearing conditions

The development of binocular vision is an active learning process comprising the development of disparity tuned neurons in visual cortex and the establishment of precise vergence control of the eyes. We present a computational model for the learning and self-calibration of active binocular vision based on the Active Efficient Coding framework, an extension of classic efficient coding ideas to active perception. Under normal rearing conditions with naturalistic input, the model develops disparity tuned neurons and precise vergence control, allowing it to correctly interpret random dot stereograms. Under altered rearing conditions modeled after neurophysiological experiments, the model qualitatively reproduces key experimental findings on changes in binocularity and disparity tuning. Furthermore, the model makes testable predictions regarding how altered rearing conditions impede the learning of precise vergence control. Finally, the model predicts a surprising new effect that impaired vergence control affects the statistics of orientation tuning in visual cortical neurons.

Effect of regulation of the NRG1/ErbB4 signaling pathway on the visual cortex synaptic plasticity of amblyopic adult rats

This study aimed to investigate the effect of the neuregulin-1/epidermal growth factor 4 (NRG1/ErbB4) signaling pathway on visual cortex synaptic plasticity in adult amblyopic rats with monocular deprivation (MD). Compared with the control group, the P wave latency and amplitude of the MD group were prolonged and low, respectively, with reduced synaptic plasticity-related protein expression, lower number of visual cortex neurons, and increased apoptosis of visual cortex neurons. Recombinant neuregulin-1 (rNRG1) administration activated the NRG1/ErbB4 signaling pathway and improved the visual cortex synaptic plasticity in MD amblyopic rats. However, the effects of rNRG1 were reversed by AG1478 (ErbB4 receptor blockers). The NRG1/ErbB4 signaling pathway in the parvalbumin neurons from MD rats was also inactivated. Amblyopic rats had significantly low cell activity and downregulated expression of synaptic plasticity-related proteins. Thus, exogenous administration of NRG1 can activate ErbB4 signal transduction and improve the damaged synaptic plasticity of the visual cortex among amblyopic rats. Further studies are warranted to explore the potential for clinical management of amblyopia.

Visual Adaptation to Scattering in Myopes

Myopes exhibit a larger capability of adaptation to defocus. Adaptation produces a boost in visual performance that can be characterized through different metrics. The ability of myopes to adapt to other sources of blur, such as diffusion, has not been studied so far. In this work, a group of 20 myopes with normal vision underwent high-contrast visual acuity (VA) measurements under different viewing conditions, wearing their refractive correction with or without a diffuser (Bangerter filter, BF). VA decreased immediately after wearing the BF of density 0.6, showing a significant relationship with the ocular refraction. After 40 minutes of binocular vision through the BF, a statistically significant increase (p = 0.02) in VA from 0.54 to 0.62 in decimal scale (from 0.3 to 0.2 logMAR) was obtained. No correlation with the refraction was observed. After removing the diffuser, VA returned to baseline. A control group (17 subjects) underwent the same experimental protocol but without diffuser filters. No significant changes in VA were found in this group. We describe a new type of contrast adaptation to blur in myopes caused by scattering, rather than by defocus. The effects of low scattering levels in vision might be relevant in the analysis of early stage of cataract, amblyopia treatments, and myopia understanding.

Fixation stability after surgical treatment of strabismus and biofeedback fixation training in amblyopic eyes

Background

Visual fixation may be affected in amblyopic patients and, moreover, its stability may be associated with the effects of amblyopic treatments on visual performance in patients with strabismus. Therefore, fixation stability is a relevant biomarker that might predict the recurrence of amblyopia after a therapeutic intervention. Microperimetric biofeedback fixation training (BFT) can stabilize visual fixation in adult patients with central vision loss. It was the purpose of the present study to evaluate the effects of BFT on fixation stability in adult amblyopic patients after surgical intervention to treat strabismus.

Methods

Participants were 12 patients with strabismus (mean age = 29.6 ± 8.5 years; 6 females) and 12 healthy volunteers (mean age = 23.8 ± 1.5 years; 9 females). The protocol included ophthalmological and microperimetric follow-ups to measure fixation stability and macular sensitivity. BFT was applied monocularly to four amblyopic eyes either on the spontaneous preferential retinal locus or to a fixation area closer to the anatomical fovea after surgical treatment of strabismus.

Results

Baseline measurements showed significantly altered microperimetric average threshold in amblyopic eyes compared to fellow eyes (p = 0.024) and compared to control eyes (p < 0.001). Fixation was unstable in amblyopic eyes compared to control eyes (p < 0.001). Fixation stability did not significantly change after surgical alignment of strabismus (p = 0.805). BFT applied to operated eyes resulted in a more stable fixation with improvements of about 50% after three months of training.

Conclusions

Fixation stability improvements following BFT highlight its potential use in adult amblyopic eyes after the surgical alignment of the strabismus. Future investigations may also consider applying this method in combination with standard treatments to improve vision in amblyopic patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-02020-3.

Virtual Reality Game Playing in Amblyopia Therapy: A Randomized Clinical Trial

PURPOSE

To compare the visual outcome of occlusion therapy with virtual reality game playing as a new therapy for children with amblyopia.

METHODS

This randomized clinical trial was performed on 50 children between 4 and 10 years old who had unilateral amblyopia. They were randomly divided into virtual reality and patching groups (n = 25 in each). The virtual reality group was trained binocularly using the virtual reality games through a head set for 1 hour per day 5 days a week for 4 weeks. Patients in the patching group occluded their non-amblyopic eyes 2, 4, and 6 hours for mild (best corrected visual acuity [BCVA] 0.2 to 0.3 logarithm of the minimum angle of resolution [logMAR]), moderate (0.3 to 0.6 logMAR), and severe (worse than 0.6 logMAR) amblyopia, respectively.

RESULTS

The mean BCVA based on logMAR units improved significantly in both groups (P < .0001), but the difference between the two groups was not significant (P = .59). BCVA based on the responded letters improved in both groups (virtual reality: P = .0001, patching: P = .001), and change in BCVA in the virtual reality group was higher than in the patching group (P = .002).

CONCLUSIONS

Virtual reality game playing was equal or superior to patching in an analysis of linear and letter BCVA, respectively. Therefore, applying this new amblyopia therapy is recommended. [J Pediatr Ophthalmol Strabismus. 2021;58(3):154-160.].

A Randomized Clinical Trial Comparing Eyetronix Flicker Glass and Patching for Treatment of Amblyopia in Children Reveals Similar Improvements in Vision

Purpose

Recently, Eyetronix Flicker Glass (EFG) has been introduced as a novel treatment for amblyopia. It alternatively deprives the visual input of each eye rapidly (e.g., 7 Hz). However, whether it is comparable with standard patching therapy is unclear. In this randomized clinical trial, we evaluate the efficacy of an EFG therapy as treatment for amblyopia in children and compare it to the patching therapy.

Methods

We tested 31 children (aged 4–13 years) with amblyopia. They were assigned into one of the two treatment groups and were treated for 12 weeks. The first group was treated with EFG for 1 h/day (Flicker Group) and the latter with a standard patch (Patching Group) for 2 h/day. We designated changes from baseline in best-corrected visual acuity (BCVA) of the amblyopic eye as our primary outcome. Changes from baseline in other visual outcomes, such as contrast sensitivity, stereopsis, and fusional vergence range were measured as secondary outcome.

Results

BCVA improved significantly at 12 weeks relative to baseline in both the Flicker (0.13 ± 0.11 logMAR; mean ± SD) and Patching Groups (0.21 ± 0.14 logMAR). However, the improvements were not significantly different between groups (p = 0.13). Contrast sensitivity also significantly improved at 3 and 12 cycles/degree between baseline and 12 weeks in both groups (p’s < 0.05). However, stereopsis and fusion range did not improve significantly in both groups.

Conclusion

An EFG therapy and patching improved BCVA similarly for children with amblyopia at 12 weeks. Both therapies improved the contrast sensitivity at 3 and 12 cycles per degree (cpd); however, only patching improved the contrast sensitivity at 6 cpd. Both therapies did not benefit binocular visual functions (stereopsis and fusional vergence range). We believe that EFG can be an additional choice for therapy.

Clinical Trial Registration

chictr.org number: ChiCTR2000034436.

Impact of Amblyopia on Visual Attention and Visual Search in Children

Purpose

The purpose of this study was to compare binocular visual attention, visual processing speeds, and visuo-cognitive search ability in children with and without amblyopia and investigate the association of visual acuity and binocular function with these measures.

Methods

Participants included 20 children with amblyopia (mean age = 9.0 ± 1.2 years; 15 anisometropic and 5 strabismic) and 20 children with normal vision development (9.5 ± 1.7 years). Vision assessment included visual acuity (monocular and binocular) and binocular function (Worth 4 Dot and Randot Preschool Stereotest). Visual attention and processing speeds were assessed using the three subtests of the Useful Field of View (UFOV; central processing, divided attention, and selective attention). Visuo-cognitive search was measured using static and dynamic presentations of the Trail Making Tests (TMTs), parts A and B, with increasing levels of executive function demand. All children performed these tasks binocularly.

Results

Children with amblyopia demonstrated slower visual processing times on the UFOV (P = 0.04), and slower completion times on the TMT search tests (P = 0.014), compared to controls. TMT performance for children with amblyopia was also more negatively impacted with increasing executive function demands on the TMT part B, compared to controls (P = 0.005). Binocular visual acuity was associated with TMT (P = 0.006) and UFOV (P = 0.07) performance, but none of the other visual function measures were related to performance on these tasks.

Conclusions

Children with amblyopia exhibit deficits in higher-order visual processing skills, including visual attention and visual search, particularly with increasing executive function demands. These findings have implications for understanding the impact of amblyopia on everyday function in children.

Emerging therapies for amblyopia

Traditional therapies to treat amblyopia, such as optical correction or occlusion/penalization of the non-amblyopic eye, are efficacious but are not without limitations such as poor adherence and decreased success with increasing age. Recently, there has been an interest in new amblyopia therapies, some using binocular techniques, through a variety of platforms including video games, movies, and virtual reality. Overall, available efficacy results for these treatments are highly variable.

The effects of amblyopia on children's reading performance after patching treatment

PURPOSE

The purpose of this study was to evaluate the effects of amblyopia on children's reading performance after the successful patching treatment with 20/20 visual acuity (VA) in the treated eye.

METHODS

The treated amblyopes group included 10 children with strabismic amblyopia diagnosed on the first visit presenting VA equal or better than 0.0 logMAR (20/20 Snellen) in the better vision eye and VA worse than 0.2 logMAR (20/32 Snellen) in the worse eye that underwent patching treatment of amblyopia reaching a final VA  equal to  0.0 logMAR in the treated eye. The control group comprised 10 children matched by age, gender and school-grade with no visual disorders. Reading performance was evaluated according to reading acuity (RA), critical print size (CPS), reading speed (RS) at 0.7 logMAR, and maximum reading speed (MRS) using the MNREAD chart.

RESULTS

Binocular reading performance was compared between groups and no statistically significant differences were found on RA, CPS, RS, or MRS (p > 0.05). When analyzing monocular reading performances of treated amblyopes, a worse RA (p = 0.04) and CPS (p = 0.04) were observed on the previously amblyopic eye when compared to the fellow eye. When comparing the fellow eye from treated amblyopes and a randomly selected eye from controls, no statistically significant differences on RA, CPS, RS, or MRS were found (p > 0.05).

CONCLUSIONS

The results suggest that even patients who reached 20/20 VA in the treated eye after patching treatment for amblyopia may present persistent impaired reading performance. These findings reinforce the importance of reading performance testing as a tool when evaluating the visual function development in amblyopic patients.

Parents' Reported Experiences When Having a Child with Cataract-Important Aspects of Self-Management Obtained from the Paediatric Cataract Register (PECARE)

Parents are a crucial part in the care of children with pediatric cataract. The aim of this study was to explore and explain sense of coherence, family self-efficacy, perceived social support, fatigue and parent reported experiences (PREM), in order to improve clinical care. Questionnaires were sent to the parents of children registered in the Swedish national Pediatric Cataract Register, PECARE, from 2006–2019 (n = 506). The response rate was 46% (n = 231), 185 mothers and 44 fathers with a mean age of 40.39 years (SD ± 6.41 years). In total, 38% of the parents reported severe fatigue, and mothers were more burdened than fathers. Sense of coherence was strongly related to fatigue, especially among parents of children with bilateral cataract. Mental fatigue and reduced motivation explained 45% of the variation in sense of coherence. Being taken seriously by the ophthalmological clinic explained over 60% of the variation in satisfaction with care when controlled for parents’ age and gender. In conclusion, fatigue is important to take in consideration when interacting with parents of children with cataract, especially those with bilateral cataract. Being taken seriously is the key marker of satisfaction with care and support from professionals. In addition to fatigue, the parents’ age and life situation affect how they perceive their own, as well as the professionals’ effort, and should be considered when tailoring family-centered care.

An update on pharmacological treatment options for amblyopia

Amblyopia is a common cause of visual impairment in children and young adults. The cornerstone in the management of this disorder is based on increasing visual stimulation of the amblyopic eye by occlusion, by administering atropine or by causing optical penalization of the dominant eye. All these treatment options have shown some limits in terms of efficacy, due to the suboptimal treatment adherence for the patients and the lack of long-term clinical outcomes. Moreover, although it is well known that clinical efficacy decreases with age, new evidence is suggesting that cortical plasticity can be induced also in older children. For these reasons, new treatment options are being studied, in order to extend the "treatment window" beyond the critical period also in older patients. In this review, we will discuss all the most promising novel pharmacological agents in the management of amblyopia.

Characterization, passive and active treatment in strabismic amblyopia: a narrative review

Strabismic amblyopia is characterized by a distorted spatial perception. In this condition, the neurofunctional disorder occurring during first years of life provoke several monocular and binocular anomalies such as crowding, deficits in the accommodative response, contrast sensitivity, and ocular motility abilities. The inhibition of the binocular function of the brain by the misaligned amblyopic eye induces a binocular imbalance leading to interocular suppression and the reduction or lack of stereoacuity. Passive treatments such as occlusion, optical and/or pharmacological penalization, and Bangerter foils has been demonstrated to be potentially useful treatments for strabismic amblyopia. Recent researches have proved new pharmacological options to improve and maintain visual acuity after occlusion treatment in strabismic amblyopia. Likewise, the active vision therapy, in the last years, is becoming a very relevant therapeutic option in combination with passive treatments, especially during and after monocular therapy, in the attempt of recovering the imbalanced binocular vision.