Treatment of congenital and early childhood cataract

The successful outcome of treatment for infant and childhood cataract depends on many factors. It is crucial that the treatment falls into a phase in which neither the eye nor the visual pathway and visual cortex are fully developed. This review summarizes the current state of knowledge and provides an overview of the epidemiology, causes and clinical forms, early detection and, above all, treatment options. Special attention is paid to time-critical stages of development, according to which the therapeutic concepts are based. Complications, such as amblyopia and glaucoma are discussed in detail. In addition to surgical aspects, much emphasis is placed on orthoptic-refractive aftercare, the quality and execution of which is the essential predictor of a good functional outcome.

Alternative Flicker Glass: a New Anti-suppression Approach to the Treatment of Anisometropic Amblyopia

INTRODUCTION

Amlyopia always presents with monocular and binocular dysfunction. In this study, we aim to investage the efficacy of alternative occlusion using liquid crystal glasses versus continuous occlusion therapy using traditional patches for treating amblyopia.

METHODS

Eligible subjects with anisometropic amblyopia were randomized into two groups: alternative flicker glass (AFG) or patching group. In the AFG group, subjects were instructed to wear the flicker glasses for 1 hour a day. The AFG is a lightweight spectacle frame with liquid crystal lenses that provide direct square-wave alternating occlusion, which were pre-programmed at temporal frequency of 7Hz. In the patching group, the patients were prescribed to wear traditional patches for 2 hours a day. The best corrected visual acuity (BCVA), contrast sensitivity function (CSF) and stereoacuity were measured at the baseline, 3 and 12 weeks.

RESULTS

In this pilot study, a total of forty children were recruited, with twenty in the AFG group. Mean BCVA improved by 0.17±0.14logMAR (95% CI=0.10 to 0.23) in the AFG group, while 0.18±0.18logMAR (95% CI=0.09 to 0.26) in the patching group from baseline to 12 weeks. The improvement of BCVA in both groups were significant (both P＜0.01), while no significant difference between the groups (P=0.82). The CSF of both low and high spatial frequencies exhibited significant improvement at 12 weeks in the AFG group (P＜0.01, respectively), while just have a significant improvement at low spatial frequency in the patching group (P＜0.01). The stereoacuity significantly improved by 504.00±848.00 (95% CI= -900.88 to -107.12) arc seconds in the AFG group (P＜0.05), while 263.50± 639.55 (95% CI=-562.82 to 35.82) arc seconds in the patching group (P＞0.05).

CONCLUSION

Alternative flicker glass was effective in improving both monocular and binocular function, which was most likely achieved by reducing the suppression and promoting binocular fusion. This therapy exhibited promise as an alternative method for amblyopia treatment.

Context-sensitive smart glasses monitoring wear position and activity for therapy compliance-A proof of concept

Purpose

To improve the acceptance and compliance of treatment of amblyopia, the aim of this study was to show that it is feasible to design an electronic frame for context-sensitive liquid crystal glasses, which can measure the state of wear position in a robust manner and detect distinct motion patterns for activity recognition.

Methods

Different temple designs with integrated temperature and capacitive sensors were developed to realize the detection of the state of wear position to distinguish three states (correct position/wrong position/glasses taken off). The electronic glasses frame was further designed as a tool for accelerometer data acquisition, which was used for algorithm development for activity classification. For this purpose, training data of 20 voluntary healthy adult subjects (5 females, 15 males) were recorded and a 10-fold cross-validation was computed for classifier selection. In order to perform functional testing of the electronic glasses frame, a proof of concept study was performed in a small group of healthy adults. Four healthy adult subjects (2 females, 2 males) were included to wear the electronic glasses frame and to protocol their activities in their everyday life according to a defined test protocol. Individual and averaged results for the precision of the state of wear position detection and of the activity recognition were calculated.

Results

Context-sensitive control algorithms were developed which detected the state of wear position and activity in a proof of concept. The pilot study revealed an average of 91.4% agreement of the detected states of wear position. The activity recognition match was 82.2% when applying an additional filter criterion. Removing the glasses was always detected 100% correctly.

Conclusion

The principles investigated are suitable for detecting the glasses’ state of wear position and for recognizing the wearer´s activity in a smart glasses concept.

Fixational eye movements abnormalities and rate of visual acuity and stereoacuity improvement with part time patching

Residual amblyopia is seen in 40% of amblyopic patients treated with part-time patching. Amblyopic patients with infantile onset strabismus or anisometropia can develop fusion maldevelopment nystagmus syndrome (FMNS). The purpose of this study was to understand the effects of presence of FMNS and clinical subtype of amblyopia on visual acuity and stereo-acuity improvement in children treated with part-time patching. Forty amblyopic children who had fixation eye movement recordings and at least 12 months of follow-up after initiating part-time patching were included. We classified amblyopic subjects per the fixational eye movements characteristics into those without any nystagmus, those with FMNS and patients with nystagmus without any structural anomalies that do not meet the criteria of FMNS or idiopathic infantile nystagmus. We also classified the patients per the clinical type of amblyopia. Patching was continued until amblyopia was resolved or no visual acuity improvement was noted at two consecutive visits. Children with anisometropic amblyopia and without FMNS have a faster improvement and plateaued sooner. Regression was only seen in patients with strabismic/mixed amblyopia particularly those with FMNS. Patients with FMNS had improvement in visual acuity but poor stereopsis with part-time patching and required longer duration of treatment.

A pilot randomized trial of contrast-rebalanced binocular treatment for deprivation amblyopia

BACKGROUND

Binocular neural architecture may be preserved in children with deprivation amblyopia due to unilateral cataract. The purpose of this study was to investigate whether a contrast-rebalanced binocular treatment, recently used with success to treat the interocular suppression and amblyopia in strabismic and anisometropic children, can contribute to rehabilitation of visual acuity in children with deprivation amblyopia secondary to monocular cataract.

METHODS

In a pilot randomized trial, 15 children (4-13 years of age) were enrolled and randomized to continue with their current treatment only (n = 7) or to continue with their current treatment and add contrast-rebalanced binocular iPad game play 5 hours/week for 4 weeks (n = 8). The primary outcome was change in visual acuity at 4 weeks.

RESULTS

Although 10 of 15 participants were patching, there was little change in visual acuity during the 3 months prior to enrollment. At the 4-week primary outcome visit, the mean improvement in visual acuity for the binocular game group was significantly greater than that for the current-treatment group (0.08 ± 0.10 logMAR vs -0.03 ± 0.05 logMAR [t_10.2 = 2.53, P = 0.03]). None of the children who had dense congenital cataract achieved improved visual acuity with binocular treatment.

CONCLUSIONS

In this study cohort, visual acuity improved over 8 weeks in children with unilateral deprivation amblyopia who played a binocular contrast-rebalanced binocular iPad game.

Rethinking amblyopia 2020

Recent work has transformed our ideas about the neural mechanisms, behavioral consequences and effective therapies for amblyopia. Since the 1700's, the clinical treatment for amblyopia has consisted of patching or penalizing the strong eye, to force the "lazy" amblyopic eye, to work. This treatment has generally been limited to infants and young children during a sensitive period of development. Over the last 20 years we have learned much about the nature and neural mechanisms underlying the loss of spatial and binocular vision in amblyopia, and that a degree of neural plasticity persists well beyond the sensitive period. Importantly, the last decade has seen a resurgence of research into new approaches to the treatment of amblyopia both in children and adults, which emphasize that monocular therapies may not be the most effective for the fundamentally binocular disorder that is amblyopia. These approaches include perceptual learning, video game play and binocular methods aimed at reducing inhibition of the amblyopic eye by the strong fellow eye, and enhancing binocular fusion and stereopsis. This review focuses on the what we've learned over the past 20 years or so, and will highlight both the successes of these new treatment approaches in labs around the world, and their failures in clinical trials. Reconciling these results raises important new questions that may help to focus future directions.

Visual Training in Virtual Reality in Adult Patients with Anisometric Amblyopia

PURPOSE

Amblyopia is one of the most common childhood disease. The average prevalence of amblyopia in children is estimated at 2-5 %. It arises during the child development until the age of six, if not treated then, it persist throught adulthood. The aim of our work is to retrospectively analyze the results of treatment of anisometropic amblyopia using dichoptical training in virtual reality in adult amblyopic patients.

MATERIALS AND METHODS

Our group consisted of 84 amblyopic patients with anisometropic amblyopia with an average age of 33.8 ± 9.4 years. Patients played a video game twice a week in the Oculus Rift 3D virtual reality. Together they completed 8 visual trainings, with one training lasting 60 minutes. Before and after the training we evaluated the best corrected visual acuity (BCVA).

DISCUSSION

Throughout the group, we observed an improvement of 0.1 BCVA from 0.48 to 0.58 Sloan table (p.

Part time patching treatment outcomes in children with amblyopia with and without fusion maldevelopment nystagmus: An eye movement study

PURPOSE

We investigated how the abnormalities of fixation eye movements (FEMs) of the amblyopic eye were linked with treatment outcomes following part-time patching therapy in children with amblyopia.

METHODS

We recruited 53 patients, with at least 12 months of patching, and measured FEMs at the end of treatment. Subjects were classified based on FEM waveforms (those without nystagmus = 21, those with nystagmus without fusion maldevelopment nystagmus (FMN) = 21, and those with FMN = 11) and based on clinical type of amblyopia (anisometropic = 18, strabismic = 6, and mixed = 29). The treatment outcomes such as duration of treatment of receiving part-time patching therapy, visual acuity and stereo-acuity deficits at the end of treatment were determined. Bivariate contour ellipse area (BCEA), fast (fixational saccade/quick phases), and slow (inter-saccadic drifts/slow phases) FEMs of the fellow and amblyopic eye were analyzed.

RESULTS

Anisometropic group had less residual amblyopia (0.23±0.19logMAR acuity) compared to strabismic/mixed (0.36±0.26) groups (p = 0.007). Treatment duration in patients without nystagmus was lower (12.6±9.5months) compared to nystagmus without FMN (25.6±23.2) and FMN (29.5±20.4) groups (p = 0.006). Patients without nystagmus had better stereopsis at the end of treatment (2.3±0.84logarcsecs) compared to nystagmus without FMN (2.6±0.84) group (p = 0.003). The majority of patients with FMN (8/11) had absent stereopsis. BCEA of the amblyopic eye was higher in patients with greater residual visual acuity deficits in patients without nystagmus. No such association was seen in Nystagmus no FMN and FMN groups. Increased amplitude of fast FEMs, increased eye position variance and eye velocity of slow FEMs were seen in patients who had received longer duration of part time patching therapy and in those with greater residual amblyopia, and poor stereopsis at the end of treatment.

CONCLUSIONS

Assessment of FEM waveforms and fast and slow FEM characteristics are important measures while describing fixation instability in amblyopia. Several FEM abnormalities were associated with stereo-acuity and visual acuity deficits and treatment duration in patients with amblyopia treated with part time patching therapy.

Implementation of a Virtual Reality rendered in Portable Devices for Strabismus Treatment based on Conventional Visual Therapy

In order to propose alternative treatments for strabismus, conventional visual therapies implemented in VR, which could be rendered in portable devices for pediatric strabismus treatment is proposed in this paper. In comparison with other virtual environments for visual correction proposes, the proposed system is based on conventional visual therapies for amblyopia and strabismus treatment. Three fundamental visual therapeutic exercises were considered in the present proposal: (1) Brock cord, (2) approach technique, and (3) convergence and divergence. The first exercise, Brock Cord, has the purpose of improving the binocular fixation for exotropia and esotropia. The second exercise pursues to normalize the Cerebral Perfusion Pressure by an approach technique. The third exercise known as fusion of eccentric circles, aims vision training by converging and diverging objects at specific distances. Before a clinical application, it was paramount important to guarantee system simplicity and versatility for both clinicians and infant patients. Therefore, the user experience evaluation of a sample of 45 students between 17 and 28 years old was undertaken. The system proposed in this paper achieved a pragmatic quality above average (1.73), a parameter that reflects simplicity and versatility. In addition, the present VR system displayed attractiveness (2.03) and hedonic (1.90) qualities above average. Then, it is expected that end-users will follow the visual exercise program.

Short-term Perceptual Learning Game Does Not Improve Patching-Resistant Amblyopia in Older Children

PURPOSE

To investigate self-administered, at-home use of a perceptual learning-based video game consisting of target detection of stimuli in different sizes, spatial frequency, orientation, and contrast as a potential dichoptic therapy to improve binocular function in amblyopic patients resistant to patching.

METHODS

Children (ages 8 to 18 years) with strabismic and/or anisometropic amblyopia were recruited from a single institution. All participants (n = 25) were prescribed 6 weeks of patching for 2 hours per day, and those whose visual acuity did not improve were randomized to binocular perceptual learning (n = 7), monocular perceptual learning (n = 8), or patching (n = 10) groups for 8 weeks in this prospective cohort study. After an 8-week long period of treatment cessation, during which participants stopped patching or perceptual learning, participants in the patching group were randomized to binocular or monocular perceptual learning training; those in the perceptual learning groups remained the same. Visual function was assessed by visual acuity, low contrast acuity, reading speed, stereoacuity, and binocularity; compliance was evaluated by exercise logs.

RESULTS

There were no significant improvements in visual function parameters, which did not vary by treatment group. However, some visual outcomes, such as binocular summation and reading speed, correlated positively with compliance to perceptual learning therapy.

CONCLUSIONS

At-home, self-administered use of this perceptual learning-based video game-based visual training does not consistently add therapeutic benefit to those with amblyopia resistant to patching. Future investigation is required to determine whether methods to increase compliance will lead to more reliable outcomes. [J Pediatr Ophthalmol Strabismus. 2020;57(3):176-184.].

Effect of optical correction on choroidal structure in children with anisohypermetropic amblyopia

The aim of this study was to assess the effect of wearing optical correction on the choroidal structure in eyes of children with anisohypermetropic amblyopia. This study was conducted at the Nara Medical University Hospital and at the Tokushima University Hospital. Twenty-nine anisohypermetropic amblyopic eyes and their fellow eyes of 29 amblyopic patients (mean age, 5.7 ± 1.7 years, range 3- to 8-years) and twenty eyes of 20 age-similar control children (4.9 ± 0.8 years, range 4- to 6-years) were studied. All patients wore optical correction and 15 patients had both optical correction and patching. The values at the baseline were compared to that at one year later. The binarization method was used to determine the total, luminal, and stromal areas of the choroid in the enhanced depth imaging optical coherence tomographic images. The best-corrected visual acuity (BCVA) of the amblyopic eyes was significantly improved after the one-year period. A large luminal area was characteristic of the amblyopic eye at the baseline, and it was significantly reduced after the optical treatment. The stromal area widened significantly in the amblyopic and fellow eyes after one year whereas there were no significant changes in the choroid of the control eyes after one year. After one-year of optical correction, the luminal/stromal ratios in the amblyopic and fellow eyes were decreased and were then not significantly different from that of the normal control eyes. There was a significant and positive correlation between the improvement of the BCVA and the stromal area at the baseline (r = 0.64, P = 0.001). Wearing corrective lenses on the amblyopic eyes improves the BCVA, and the choroidal structure of the amblyopic eye becomes closer to that of the control eyes. The narrowed luminal area is a specific response of the amblyopic eye associated with the correction of the refractive error. The larger stromal area in the amblyopic eyes at the baseline is a predictive factor for improvements of the BCVA.

Evaluating the Acute Effect of Stereoscopic Recovery by Dichoptic Stimulation Using Electroencephalogram

Amblyopia is a common developmental disorder in adolescents and children. Stereoscopic loss is a symptom of amblyopia that can seriously affect the quality of patient's life. Recent studies have shown that the push-pull perceptual learning protocol had a positive effect on stereoscopic recovery. In this study, we developed a stereoscopic training method using a polarized visualization system according to the push-pull protocol. Dichoptic stimulation for 36 anisometropic and amblyopic subjects and 33 children with normal visual acuity (VA) has been conducted. Electroencephalogram (EEG) was used to evaluate the neurophysiological changes before, during, and after stimulation. For the anisometropic and amblyopic subjects, the statistical analysis demonstrated significant differences (p < 0.01) in the beta rhythm at the middle temporal and occipital lobes, while the EEG from the normal VA subjects indicated no significant changes when comparing the results before and after training. We concluded that the dichoptic training in our study can activate the middle temporal visual area and visual cortex. The EEG changes can be used to evaluate the training effects. This study also found that the beta band EEG acquired during visual stimulation at the dorsal visual stream can be potentially used for predicting acute training effect. The results facilitated the optimization of the individual training plan.

Occlusion for stimulus deprivation amblyopia

BACKGROUND

Stimulus deprivation amblyopia (SDA) develops due to an obstruction to the passage of light secondary to a condition such as cataract. The obstruction prevents formation of a clear image on the retina. SDA can be resistant to treatment, leading to poor visual prognosis. SDA probably constitutes less than 3% of all amblyopia cases, although precise estimates of prevalence are unknown. In high-income countries, most people present under the age of one year; in low- to middle-income countries, people are likely to be older at the time of presentation. The mainstay of treatment is correction of the obstruction (e.g., removal of the cataract) and then occlusion of the better-seeing eye, but regimens vary, can be difficult to execute, and traditionally are believed to lead to disappointing results.

OBJECTIVES

To evaluate the effectiveness of occlusion therapy for SDA in an attempt to establish realistic treatment outcomes and to examine evidence of any dose-response effect and assess the effect of the duration, severity, and causative factor on the size and direction of the treatment effect.

SEARCH METHODS

We searched CENTRAL (2018, Issue 12), which contains the Cochrane Eyes and Vision Trials Register; Ovid MEDLINE; Embase.com; and five other databases. We used no date or language restrictions in the electronic searches. We last searched the databases on 12 December 2018.

SELECTION CRITERIA

We planned to include randomized controlled trials (RCTs) and controlled clinical trials of participants with unilateral SDA with visual acuity worse than 0.2 LogMAR or equivalent. We specified no restrictions for inclusion based upon age, gender, ethnicity, comorbidities, medication use, or the number of participants.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology.

MAIN RESULTS

We identified no trials that met the inclusion criteria specified in the protocol for this review.

AUTHORS' CONCLUSIONS

We found no evidence from RCTs or quasi-randomized trials on the effectiveness of any treatment for SDA. RCTs are needed in order to evaluate the safety and effectiveness of occlusion, duration of treatment, level of vision that can be realistically achieved, effects of age at onset and magnitude of visual defect, optimum occlusion regimen, and factors associated with satisfactory and unsatisfactory outcomes with the use of various interventions for SDA.

Effect of Primary Occlusion Therapy in Asymmetric, Bilateral Amblyopia

PURPOSE

Many bilateral amblyopia patients have asymmetric visual acuity (VA). There is no standard treatment for these patients, and outcomes have not been well described. Our goal is to compare VA outcomes in this group based on timing of occlusion therapy.

DESIGN

Retrospective interventional comparative case series.

METHODS

Setting: Institutional practice. PatientPopulation: Patients diagnosed with amblyopia at Boston Children's Hospital between 2010 and 2014. InclusionCriteria: VA ≥ 0.3 logMAR bilaterally by objective optotype-based measures, interocular difference (IOD) ≥ 0.18 logMAR, age 2-12 years. ExclusionCriteria: Loss to follow-up, managed surgically, deprivation amblyopia. Patients had either primary or secondary occlusion (primary = initiated when VA ≥ 0.3 logMAR bilaterally; secondary = initiated to correct residual IOD once VA improved to ≤0.18 logMAR in the stronger eye). ObservationProcedure: Patient demographics, VA, IOD, and stereopsis were compared between groups. OutcomeMeasures: VA improvement at 12-18 months and at last visits.

RESULTS

Of 2,200 patients reviewed, 167 (7.6%) had asymmetric, bilateral amblyopia; 98 met inclusion and exclusion criteria. Patients were equally divided between primary (n = 50) and secondary (n = 48) occlusion groups. There were no differences in demographics, baseline VA, or IOD between groups (P ≥ .22), although the primary occlusion group had a higher proportion of strabismic amblyopia (P = .007). VA in both eyes, IOD, and stereopsis improved similarly between groups, even after stratifying by amblyopia subtype (P ≥ .48). The secondary occlusion group was more likely to achieve 20/30 bilaterally and IOD ≤ 1 line at 12-18 months (P ≤ .4), although this equalized by the last visit.

CONCLUSION

In patients with asymmetric, bilateral amblyopia, VA improved by 4 lines in the weaker eye and 2 lines in the stronger eye, while IOD improved by 2 lines, irrespective of occlusion status. Primary occlusion thus provided no further benefit over spectacle correction alone.

Correlation between higher-order aberrations and visual acuity recovery (CoHORT) after spectacles treatment for pediatric refractive amblyopia: A pilot study using iDesign measurement

Purpose

To determine the correlation between higher-order aberrations (HOAs) and best-corrected visual acuity (BCVA) recovery speed after spectacles treatment using iDesign measurements in refractive amblyopic children.

Methods

This is a prospective case series. Children aged from 3 to 7 years with refractive amblyopia (Landolt C equivalent < 0.8) were recruited. All participants were followed for at least 6 months after full correction of the refraction error by spectacles. The HOAs were measured using iDesign before and after cycloplegia at first visit and at 3-month intervals. Then correlation between BCVA recovery after treatment for 6 months and HOAs was determined.

Results

We analyzed 24 eyes of 12 children (mean age, 4.5 years). Baseline mean BCVA was logarithm of minimal angle of resolution (logMAR) 0.335 (Landolt C equivalent 0.46), which improved to logMAR 0.193 (Landolt C equivalent 0.64) after treatment with full-correction spectacles for 6 months. The amblyopic eye BCVA recovery was negatively correlated with tetrafoil with/without cycloplegia (P = 0.006 and 0.022, respectively) and trefoil with cycloplegia (P = 0.049).

Conclusions

trefoil and tetrafoil measured with iDesign negatively correlates with the BCVA recovery speed of refractive amblyopic eyes after spectacles treatment in this pilot study. The current study results may aid in further investigation for diagnosis and treatment of refractory refractive and idiopathic amblyopia.

Amblyopia: Detection and Treatment

Amblyopia is the leading cause of monocular vision loss in children. Early recognition and treatment are important to prevent vision loss. The U.S. Preventive Services Task Force recommends vision screening for all children at least once between three and five years of age to detect the presence of amblyopia or its risk factors. The American Association for Pediatric Ophthalmology and Strabismus and the American Academy of Pediatrics recommend routine, age-appropriate red reflex testing, examination for signs of strabismus, and vision chart testing. Photoscreening may be a useful adjunct to traditional vision screening, but there is limited evidence that it improves visual outcomes. Treatments for amblyopia include patching, atropine eye drops, and optical penalization of the nonamblyopic eye. In children with moderate amblyopia, patching for two hours per day is as effective as six hours, and daily atropine is as effective as daily patching. Children younger than seven years receive the most benefit from treatment, but older children may still benefit. Amblyopia recurs in 25% of children, so continued surveillance is important.

Quality of life and mental health in amblyopic children treated with and without occlusion therapy

PURPOSE

To assess the long-term (≥1 year) psychosocial effects of occlusion therapy in children with refractive amblyopia and their caregivers.

METHODS

Multiple self-reported questionnaires were used to investigate HRQoL, anxiety, depression, and stress in a cross-sectional study of children with refractive amblyopia and their caregivers. Children were divided into two subgroups: those treated with glasses only and those treated with both glasses and occlusion therapy who had stopped wearing a patch at least 1 year earlier.

RESULTS

A total of 79 children were included: 32 in the refraction-only group and 47 in the glasses + occlusion group. Median age of subjects was 12 years (IQR = 3.0). Mean age of the 79 caregivers was 41.9 ± 5.0 years. No significant differences were found for any of the psychosocial outcomes analyzed between children treated with glasses and patching and those treated with glasses only. The differences remained insignificant between children according to age of first occlusion (<6 vs ≥6 years). The only significant (but not clinically relevant) difference observed for caregivers was a higher score in the depression dimension of the Hospital Anxiety and Depression Scale for caregivers of children treated with glasses only (P = 0.036; effect size = 0.23).

CONCLUSIONS

In our study cohort, patching was not associated with long-term negative psychosocial outcomes in children with refractive amblyopia treated with occlusion therapy.

Amblyopia with Eccentric Fixation: Is Inverse Occlusion Still an Option?

Purpose: To present a treatment protocol for patients with amblyopia and eccentric fixation who do not respond to conventional occlusion therapy.Material and methods: In this consecutive case series, 11 patients were included (age 3.5 to 5.0), all with mixed amblyopia and eccentric fixation, who had only minor improvement of their visual acuity (VA) despite good compliance with 6 hours/day to full time occlusion of the sound eye for at least 6 months. Visual acuity of amblyopic eyes ranged from 20/50 to 20/400 at the time of initiation of inverse occlusion. Total inverse occlusion of the amblyopic eye was prescribed for 4 to 8 weeks to convert the steady eccentric fixation to wandering fixation. No binocular viewing was allowed. Once the fixation became wandering, the sound eye was occluded day and night and in most patients, a red filter was placed before the amblyopic eye to stimulate foveal fixation. In nine patients, the fixation became central and occlusion of the sound eye was continued without red filter. All children continued full time occlusion until VA failed to improve after two consecutive visits despite good compliance.Results: In nine children, the VA improved to at least 20/32 in the amblyopic eye. The VA of the sound eye did not change.Conclusion: Inverse occlusion is still a valuable option if conventional occlusion appears to be insufficient to improve VA in amblyopic eyes with eccentric fixation. Full time inverse occlusion should be performed until the eccentric point is no longer used for fixation and should be followed with full time occlusion of the sound eye. Placing a red filter before the amblyopic eye may be helpful to stimulate foveal fixation.

Eye Conditions in Infants and Children: Amblyopia and Strabismus

Amblyopia is a developmental disorder of the central nervous system. It occurs in infancy or early childhood when the visual system is susceptible to issues that interrupt development. In the United States, up to 2% of infants and children ages 6 to 71 months have amblyopia. Risk factors for amblyopia include hyperopia, astigmatism, and myopia. Risk factors are more common in children who are premature or small for gestational age. Management of amblyopia in children includes optical correction of refractive errors, occlusion therapy (patching), pharmacotherapy, and surgery. Strabismus occurs when one eye can focus on an object or a point but the other eye turns inward toward the nose (esotropia), upward (hypertropia), downward (hypotropia), or outward toward the temple (exotropia). The patient may report diplopia or vision loss and may present with compensating posture such as a head tilt. Nonsurgical (ie, eyeglasses, prisms, onabotulinumtoxinA) and surgical management options are available to manage strabismus.

Conventional occlusion versus pharmacologic penalization for amblyopia

BACKGROUND

Amblyopia is defined as impaired visual acuity in one or both eyes without demonstrable abnormality of the visual pathway, and is not immediately resolved by wearing glasses.

OBJECTIVES

In performing this systematic review, we aimed to synthesize the best available evidence regarding the effectiveness and safety of conventional occlusion therapy compared to atropine penalization in treating amblyopia.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2018, Issue 8); Ovid MEDLINE; Ovid Embase; LILACS BIREME; ClinicalTrials.gov; ISRCTN; and the WHO ICTRP on 7 September 2018.

SELECTION CRITERIA

We included randomized/quasi-randomized controlled trials comparing conventional occlusion to atropine penalization for amblyopia.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened abstracts and full-text articles, abstracted data, and assessed risk of bias.

MAIN RESULTS

We included seven trials (five randomized controlled trials and two quasi-randomized controlled trials) conducted in six countries (China, India, Iran, Ireland, Spain, and the United States) with a total of 1177 amblyopic eyes. Three of these seven trials were from the original 2009 version of the review. We assessed two trials as having a low risk of bias across all domains, and the remaining five trials as having unclear or high risk of bias for some domains.As different occlusion modalities, atropine penalization regimens, and populations were used across the included trials, we did not conduct any meta-analysis due to clinical and statistical heterogeneity. Evidence from six trials (two at low risk of bias) suggests that atropine penalization is as effective as conventional occlusion in improving visual acuity. Similar improvement in visual acuity was reported at all time points at which it was assessed, ranging from five weeks (improvement of 1 line) to 10 years (improvement of greater than 3 lines). At six months, although most participants (363/522) come from a trial rated as at low risk of bias with a precise estimate (mean difference (MD) 0.03, 95% confidence interval (CI) 0.00 to 0.06), two other trials rated as at high risk of bias produced inconsistent estimates and wide confidence intervals (MD -0.02, 95% CI -0.11 to 0.07 and MD -0.14, 95% CI -0.23 to -0.05; moderate-certainty evidence). At 24 months, additional improvement was found in both groups, but there continued to be no meaningful difference between those receiving occlusion and those receiving atropine therapies (moderate-certainty evidence).We did not find any difference in ocular alignment, stereo acuity, or sound eye visual acuity between occlusion and atropine penalization groups (moderate-certainty evidence). Both treatments were well tolerated. Atropine was associated with better adherence (moderate-certainty evidence) and quality of life (moderate-certainty evidence), but also a higher reported risk of adverse events in terms of mild reduction in the visual acuity of the sound eye not requiring treatment and light sensitivity (high-certainty evidence). Skin, lid, or conjunctival irritation were more common among participants receiving patching than those receiving atropine (high-certainty evidence). Atropine penalization costs less than conventional occlusion.

AUTHORS' CONCLUSIONS

Both conventional occlusion and atropine penalization produce visual acuity improvement in the amblyopic eye. Atropine penalization appears to be as effective as conventional occlusion, although the magnitude of improvement differed among the trials we analyzed.

Binocular amblyopia treatment with contrast-rebalanced movies

BACKGROUND

Binocular amblyopia treatments promote visual acuity recovery and binocularity by rebalancing the signal strength of dichoptic images. Most require active participation by the amblyopic child to play a game or perform a repetitive visual task. The purpose of this study was to investigate a passive form of binocular treatment with contrast-rebalanced dichoptic movies.

METHODS

A total of 27 amblyopic children, 4-10 years of age, wore polarized glasses to watch 6 contrast-rebalanced dichoptic movies on a passive 3D display during a 2-week period. Amblyopic eye contrast was 100%; fellow eye contrast was initially set to a lower level (20%-60%), which allowed the child to overcome suppression and use binocular vision. Fellow eye contrast was incremented by 10% for each subsequent movie. Best-corrected visual acuity, random dot stereoacuity, and interocular suppression were measured at baseline and at 2 weeks.

RESULTS

Amblyopic eye best-corrected visual acuity improved from 0.57 ± 0.22 at baseline to 0.42 ± 0.23 logMAR (t₂₆ = 8.09; P < 0.0001; 95% CI for improvement, 0.11-0.19 logMAR). Children aged 3-6 years had more improvement (0.21 ± 0.11 logMAR) than children aged 7-10 years (0.11 ± 0.06 logMAR; t₂₅ = 3.05; P = 0.005). Children with severe amblyopia (≥0.7 logMAR) at baseline experienced greater improvement (0.24 ± 0.12 logMAR) than children with moderate amblyopia at baseline (0.12 ± 0.06 logMAR; t₂₅ = 3.49; P = 0.002).

CONCLUSIONS

In this cohort, passive viewing of contrast-rebalanced dichoptic movies effectively improved visual acuity in amblyopic subjects. The degree of improvement observed was similar to that previously reported for 2 weeks of binocular games treatment and with 3-4 months of occlusion therapy.

Inverse Occlusion: A Binocularly Motivated Treatment for Amblyopia

Recent laboratory findings suggest that short-term patching of the amblyopic eye (i.e., inverse occlusion) results in a larger and more sustained improvement in the binocular balance compared with normal controls. In this study, we investigate the cumulative effects of the short-term inverse occlusion in adults and old children with amblyopia. This is a prospective cohort study of 18 amblyopes (10-35 years old; 2 with strabismus) who have been subjected to 2 hours/day of inverse occlusion for 2 months. Patients who required refractive correction or whose refractive correction needed updating were given a 2-month period of refractive adaptation. The primary outcome measure was the binocular balance which was measured using a phase combination task; the secondary outcome measures were the best-corrected visual acuity which was measured with a Tumbling E acuity chart and converted to logMAR units and the stereoacuity which was measured with the Random-dot preschool stereogram test. The average binocular gain was 0.11 in terms of the effective contrast ratio (z = -2.344, p = 0.019, 2-tailed related samples Wilcoxon Signed Rank Test). The average acuity gain was 0.13 logMAR equivalent (t(17) = 4.76, p < 0.001, 2-tailed paired samples t-test). The average stereoacuity gain was 339 arc seconds (z = -2.533, p = 0.011). Based on more recent research concerning adult ocular dominance plasticity, we conclude that inverse occlusion in adults and old children with amblyopia does produce long-term gains to binocular balance and that acuity and stereopsis can improve in some subjects.

Development of a core outcome set for amblyopia, strabismus and ocular motility disorders: a review to identify outcome measures

BACKGROUND

Core Outcome Sets (COS) are defined as the minimum sets of outcomes that should be measured and reported in all randomised controlled trials to facilitate combination and comparability of research. The aim of this review is to produce an item bank of previously reported outcome measures from published studies in amblyopia, strabismus and ocular motility disorders to initiate the development of COS.

METHODS

A review was conducted to identify articles reporting outcome measures for amblyopia, strabismus and ocular motility disorders. Using systematic methods according to the COMET handbook we searched key electronic bibliographic databases from 1st January 2011 to 27th September 2016 using MESH terms and alternatives indicating the different subtypes of amblyopia, strabismus and ocular motility disorders in relation to treatment outcomes and all synonyms. We included Cochrane reviews, other systematic reviews, controlled trials, non-systematic reviews and retrospective studies. Data was extracted to tabulate demographics of included studies, primary and secondary outcomes, methods of measurement and their time points.

RESULTS

A total of 142 studies were included; 42 in amblyopia, 33 in strabismus, and 68 in ocular motility disorders (one study overlap between amblyopia and strabismus). We identified ten main outcome measure domains for amblyopia, 14 for strabismus, and ten common "visual or motility" outcome measure domains for ocular motility disorders. Within the domains, we found variable nomenclature being used and diversity in methods and timings of measurements.

CONCLUSION

This review highlights discrepancies in outcome measure reporting within published literature for amblyopia, strabismus and ocular motility and it generated an item bank of the most commonly used and reported outcome measures for each of the three conditions from recent literature to start the process of COS development. Consensus among all stakeholders including patients and professionals is recommended to establish a useful COS.

New advances in amblyopia therapy I: binocular therapies and pharmacologic augmentation

Amblyopia therapy options have traditionally been limited to penalisation of the non-amblyopic eye with either patching or pharmaceutical penalisation. Solid evidence, mostly from the Pediatric Eye Disease Investigator Group, has validated both number of hours a day of patching and days per week of atropine use. The use of glasses alone has also been established as a good first-line therapy for both anisometropic and strabismic amblyopia. Unfortunately, visual acuity equalisation or even improvement is not always attainable with these methods. Additionally, non-compliance with prescribed therapies contributes to treatment failures, with data supporting difficulty adhering to full treatment sessions. Interest in alternative therapies for amblyopia treatment has long been a topic of interest among researchers and clinicians alike. Incorporating new technology with an understanding of the biological basis of amblyopia has led to enthusiasm for binocular treatment of amblyopia. Early work on perceptual learning as well as more recent enthusiasm for iPad-based dichoptic training have each generated interesting and promising data for vision improvement in amblyopes. Use of pharmaceutical augmentation of traditional therapies has also been investigated. Several different drugs with unique mechanisms of action are thought to be able to neurosensitise the brain and enhance responsiveness to amblyopia therapy. No new treatment has emerged from currently available evidence as superior to the traditional therapies in common practice today. But ongoing investigation into the use of both new technology and the understanding of the neural basis of amblyopia promises alternate or perhaps better cures in the future.

Effectiveness of binocularity-stimulating treatment in children with residual amblyopia following occlusion

BACKGROUND

To evaluate the effectiveness of binocularity-stimulating treatment in children with residual amblyopia following occlusion therapy for more than 6 months.

METHODS

Of patients with amblyopia caused by anisometropia and/or strabismus, patients with residual amblyopia following more than 6 months of occlusion therapy were included. Subjects underwent one of the following types of binocularity-stimulating therapy: Bangerter foil (BF), head-mounted display (HMD) game, or BF/HMD combination (BF + HMD). Factors including age, sex, types of amblyopia, visual acuity, and duration of treatment were investigated. Baseline and final (after at least 2 months of treatment) visual acuity were also compared.

RESULTS

Twenty-two patients with a mean age of 8.7 ± 1.3 years were included. Seven patients had anisometropic amblyopia, 8 patients had strabismic amblyopia, and 7 patients had combined amblyopia. After 4.4 ± 1.8 months of treatment, logarithm of the minimum angle of resolution (logMAR) visual acuity in the amblyopic eye improved from 0.22 ± 0.20 to 0.18 ± 0.15. Five of 22 patients (22.7%) gained more than 0.2 logMAR, including 1 of 10 patients (10.0%) in the BF group, 2 of 7 patients (28.6%) in the HMD group, and 2 of 5 patients (40.0%) in the BF + HMD group. No significant differences in clinical characteristics were identified among the three groups.

CONCLUSIONS

Binocularity-stimulating therapy is somewhat beneficial in children with residual amblyopia and might be attempted when children no longer benefit from sufficient long-term period of occlusion therapy.

Assessing amblyopia treatment using multifocal visual evoked potentials

BACKGROUND

To evaluate the effect of occlusion treatment for anisometropic amblyopia using multifocal visual evoked potentials (mfVEPs).

METHODS

The patients for this study comprised 19 patients (mean age 6.05 ± 1.65 years) with anisometropic amblyopia underwent mfVEP analysis using the RETIscan® system before and after occlusion treatment. After dividing the area into six ring areas and four quadrants, we analyzed the amplitudes and latencies of the mfVEPs.

RESULTS

The amplitudes of ring 1 (central field) in amblyopic eyes after treatment were significantly higher than those in the other rings (p = 0.001). The mfVEP amplitudes in each of the six rings between amblyopic eyes and fellow eyes at diagnosis and after occlusion treatment showed no significant differences. In quadrant 1 the amplitudes of the amblyopic eyes and fellow eyes were significantly different at the time of diagnosis (p = 0.005), whereas after occlusion treatment there was no significant difference (p = 0.888). The amplitudes for each of the six rings at diagnosis and after occlusion treatment in amblyopic eyes versus fellow eyes showed no significant difference. There were also no differences in the amplitudes in each of the four quadrants at the time of diagnosis and after occlusion treatment in amblyopic eyes versus fellow eyes. No significant difference was found in the comparison of latency values in each of the six rings or in each of the four quadrants at diagnosis and after occlusion treatment in amblyopic eyes versus their fellow eyes.

CONCLUSIONS

The amplitudes of quadrant 1 in amblyopic eyes compared with those of the fellow eyes at diagnosis were increased after occlusion treatment. Changes of the difference between amblyopic eyes and fellow eyes in quadrant 1 after occlusion treatment could be a useful, objective method for monitoring improvement in visual acuity.

Amblyopia in High Accommodative Convergence/Accommodation Ratio Accommodative Esotropia. Influence of Bifocals on Treatment Outcome

PURPOSE

To study the influence of bifocal use on amblyopia treatment outcome in high accommodative convergence/accommodation (AC/A) ratio accommodative esotropia with deviation only at near.

DESIGN

Retrospective comparative case series.

METHODS

Setting: Tertiary referral center.

PATIENTS

Children with high AC/A ratio accommodative esotropia aged 3-8 years old, with deviation only at near with glasses, neutralized with bifocal lenses (follow-up 1 year).

INTERVENTION

Amblyopia was treated with patching. We compared bifocal and single-vision glasses users at 6 months and 1 year, with control of potential confounding variables (multiple regression).

MAIN OUTCOME MEASURES

LogMAR lines of improvement in visual acuity of the amblyopic eye, and improvement in stereoacuity.

RESULTS

Of 78 children, 61 were eligible. All patients wore single-vision glasses for 2 months (baseline visit), 46 of them changed to bifocals. Of 27 initially amblyopic children, 21 remained amblyopic at 2-month baseline (13 of them changed to bifocals). After adjustment for initial deviation, refraction, age, and amblyopia, improvement of visual acuity in the amblyopic eye was larger in the bifocal vs single-vision group at 6 months (mean 2.6 [95% confidence interval (CI): 1.9-2.9] logMAR lines vs mean 1.9 [95% CI: 0.5-2.2] logMAR lines, respectively, P = .01), but not at 1 year (mean 2.7 [95% CI: 2.2-3.1] logMAR lines vs mean 2.3 [95% CI: 1.6-3.1] logMAR lines, respectively, P = .3). Improvement of stereoacuity was not significantly different between the 2 groups.

CONCLUSIONS

Use of bifocals may provide a transient advantage, but improvement in visual acuity and stereopsis is equal with single-vision glasses over time.

Prognostic Value of Visual Evoked Responses in Childhood Amblyopia

We assessed the possible clinical utility of pattern reversal visual evoked potentials in predicting the success of pleoptic treatment. Thirty amblyopic children –- 16 strabismic, 11 anisometropic and three of refractive type (in all cases the amblyopia was monocular) –- and ten children without amblyopia (control group) were examined by conventional psychometric methods. Visual evoked potentials (VEP) to pattern reversal stimulation were also recorded. The amblyopic group was treated with occlusion of the preferred eye for three to six months. Psychometric and VEP tests were repeated in 15 amblyopic children after the treatment. The pre-treatment VEP amplitude side-differences (between amblyopic and better fellow eye) were significant, with first positive wave, P1, being invariably lower on the amblyopic side. We correlated the side-differences in visual acuity with the corresponding side-differences in amplitude and latency of the P1 wave. In the former the correlation coefficient was r = 0.47 (p<0.01), and in the latter r = 0.65 (p<0.01). Latency was prolonged in the eyes with significantly reduced visual acuity in which the wave form was also typical for amblyopia. We then correlated the difference between pre- and post- treatment visual acuity of the amblyopic eye with the pre- and post-treatment difference in amplitude (correlation coeff. r-0.51 (p=0.05)) and latency of the P1 wave (correlation coeff. r=0.40 (p>0.05)). Finally, by correlating the pre- and post-treatment difference in visual acuity with the pretreatment P1 amplitude and latency (for the former, there was no regular interdependence, and for the latter r=-0.64 (p=0.01)), we tried to test our assumption that an alteration of VEP indicates poor visual rehabilitation of the amblyopic eye. Although the correlation was not unanimous, this study showed that VEP recording may still serve as an extra aid in predicting the therapeutic outcome in amblyopic children.

Practice Patterns in the Management of Amblyopia: A Survey Study

PURPOSE

To characterize current practice preferences of pediatric ophthalmologists in the management of amblyopia and whether these are influenced by demographic variables.

METHODS

A 10-question survey was distributed to all pediatric ophthalmologists and fellows attending the Annual Joseph H. Calhoun Pediatric Ophthalmology Forum at Wills Eye Hospital in 2016. The questionnaire consisted of demographic information and clinical management of amblyopia using clinical scenarios commonly encountered in pediatric ophthalmology practice.

RESULTS

Of the 133 pediatric ophthalmologists who attended, 74 completed the survey, all of which were included in the data analysis. Seventy-six percent of respondents prescribed refractive correction to a 3 year old with untreated anisometropic amblyopia prior to initiating occlusion therapy. For a child with coexisting exotropia, 57% recommended refractive and occlusion therapy until significant visual improvement, then surgery; however, 30% would perform surgery earlier. Fifty-seven percent stopped occlusion therapy at 10 years of age or older. Sixty-four percent estimated a patient patching compliance rate of 50% to 75%. There was no significant relationship (P < .05) between any of the demographic variables, indicating that no group was more or less likely to respond to the question in any way.

CONCLUSIONS

This study highlights the lack of a unified approach to certain aspects of amblyopia management. Physician-related demographic variables did not significantly affect clinical decision-making; however, variation did exist among respondents, a finding that warrants further investigation. [J Pediatr Ophthalmol Strabismus. 2018;55(2):100-106.].

A Randomized Trial of a Binocular iPad Game Versus Part-Time Patching in Children Aged 13 to 16 Years With Amblyopia

PURPOSE

To compare visual acuity (VA) improvement in teenagers with amblyopia treated with a binocular iPad game vs part-time patching.

METHODS

One hundred participants aged 13 to <17 years (mean 14.3 years) with amblyopia (20/40 to 20/200, mean ∼20/63) resulting from strabismus, anisometropia, or both were enrolled into a randomized clinical trial. Participants were randomly assigned to treatment for 16 weeks of either a binocular iPad game prescribed for 1 hour per day (n = 40) or patching of the fellow eye prescribed for 2 hours per day (n = 60). The main outcome measure was change in amblyopic eye VA from baseline to 16 weeks.

RESULTS

Mean amblyopic eye VA improved from baseline by 3.5 letters (2-sided 95% confidence interval [CI]: 1.3-5.7 letters) in the binocular group and by 6.5 letters (2-sided 95% CI: 4.4-8.5 letters) in the patching group. After adjusting for baseline VA, the difference between the binocular and patching groups was -2.7 letters (95% CI: -5.7 to 0.3 letters, P = .082) or 0.5 lines, favoring patching. In the binocular group, treatment adherence data from the iPad device indicated that only 13% of participants completed >75% of prescribed treatment.

CONCLUSIONS

In teenagers aged 13 to <17 years, improvement in amblyopic eye VA with the binocular iPad game used in this study was not found to be better than patching, and was possibly worse. Nevertheless, it remains unclear whether the minimal treatment response to binocular treatment was owing to poor treatment adherence or lack of treatment effect.

Effect of 4-Month Intermittent Atropine Penalization in Amblyopic Children for Whom Patch Therapy Had Failed

PURPOSE

To evaluate the effect of 4-month intermittent atropine penalization in children with amblyopia for whom patch therapy had failed and to analyze the factors associated with treatment success.

METHODS

This retrospective observational study included participants who visited the hospital between January 1, 2011, and December 31, 2015. Forty-one children with amblyopia for whom patch therapy had failed were included and their medical records were analyzed retrospectively. They were treated with 1% atropine eye drops in the sound eye twice per week for 4 months. Treatment success was defined as a best corrected visual acuity (BCVA) improvement of two lines in the amblyopic eye. Age, cause of amblyopia, pretreatment BCVA at the start of atropine penalization in the amblyopic eye, age at the start of eyeglass prescription, age at the start of patch therapy, duration, compliance with and total amount of patch therapy, type of refraction, type of strabismus, and cause of failure of patch therapy were analyzed and compared between two groups: the failure and success groups.

RESULTS

Twenty of 41 patients (48.8%) showed treatment success. The mean age was 5.59 ± 1.52 years and the mean BCVA of the amblyopic eye was 0.40 ± 0.20 logarithm of the minimum angle of resolution (logMAR). Younger age and poor pretreatment BCVA at the start of atropine penalization in the amblyopic eye were the factors associated with treatment success.

CONCLUSIONS

Intermittent atropine penalization for 4 months can improve BCVA in children with amblyopia for whom patch therapy has failed. Atropine penalization can be especially effective in younger children and those with poor BCVA at the start of atropine penalization in the amblyopic eye. [J Pediatr Ophthalmol Strabismus. 2017;54(6):375-380.].

A complete investigation of monocular and binocular functions in clinically treated amblyopia

The gold standard of a successful amblyopia treatment is full recovery of visual acuity (VA) in the amblyopic eye, but there has been no systematic study on both monocular and binocular visual functions. In this research, we aimed to quantify visual qualities with a variety of perceptual tasks in subjects with treated amblyopia. We found near stereoacuity and pAE dominance in binocular rivalry in "treated" amblyopia were largely comparable to those of normal subjects. CSF of the pAE remained deficient in high spatial frequencies. The binocular contrast summation ratio is significantly lower than normal standard. The interocular balance point is 34%, indicating that contrast in pAE is much less effective as the same contrast in pFE in binocular phase combination. Although VA, stereoacuity and binocular rivalry at low spatial frequency in treated amblyopes were normal or nearly normal, the pAE remained "lazy" in high frequency domain, binocular contrast summation, and interocular phase combination. Our results suggest that structured monocular and binocular training are necessary to fully recover deficient functions in amblyopia.

Vision Screening in Children Aged 6 Months to 5 Years: Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Preschool vision screening could allow detection and treatment of vision abnormalities during a critical developmental stage, preserving function and quality of life.

OBJECTIVE

To review the evidence on screening for and treatment of amblyopia, its risk factors, and refractive error in children aged 6 months to 5 years to inform the US Preventive Services Task Force.

DATA SOURCES

MEDLINE, Cochrane Library, CINAHL, and trial registries through June 2016; references; and experts, with surveillance of the literature through June 7, 2017.

STUDY SELECTION

English-language randomized clinical trials (RCTs) or prospective cohort studies that evaluated screening, studies evaluating test accuracy, RCTs of treatment vs inactive controls, and cohort studies or case-control studies assessing harms.

DATA EXTRACTION AND SYNTHESIS

Dual review of abstracts, full-text articles, and study quality; qualitative synthesis of findings. Studies were not quantitatively pooled because of clinical and methodological heterogeneity.

MAIN OUTCOMES AND MEASURES

Visual acuity, amblyopia, school performance, functioning, quality of life, test accuracy, testability, and harms.

RESULTS

Forty studies were included (N = 34 709); 34 evaluated test accuracy. No RCTs compared screening with no screening, and no studies evaluated school performance, function, or quality of life. Studies directly assessing earlier or more intensive screening were limited by high attrition. Positive likelihood ratios were between 5 and 10 for amblyopia risk factors or nonamblyogenic refractive error in most studies of test accuracy and were greater than 10 in most studies evaluating combinations of clinical tests. Inability to cooperate may limit use of some tests in children younger than 3 years. Studies with low prevalence (<10%) of vision abnormalities showed high false-positive rates (usually >75%). Among children with amblyopia risk factors (eg, strabismus or anisometropia), patching improved visual acuity of the amblyopic eye by a mean of less than 1 line on a standard chart after 5 to 12 weeks for children pretreated with glasses (2 RCTs, 240 participants); more children treated with patching than with no patching experienced improvement of at least 2 lines (45% vs 21%; P = .003; 1 RCT, 180 participants). Patching plus glasses improved visual acuity by about 1 line after 1 year (0.11 logMAR [95% CI, 0.05-0.17]) for children not pretreated with glasses (1 RCT, 177 participants). Glasses alone improved visual acuity by less than 1 line after 1 year (0.08 logMAR [95% CI, 0.02-0.15], 1 RCT, 177 participants).

CONCLUSIONS AND RELEVANCE

Studies directly evaluating the effectiveness of screening were limited and do not establish whether vision screening in preschool children is better than no screening. Indirect evidence supports the utility of multiple screening tests for identifying preschool children at higher risk for vision problems and the effectiveness of some treatments for improving visual acuity outcomes.

[Study of New Amblyopia Diagnostic and Treatment Method and System Implementation]

Amblyopia is the common disease in the children's growth. There are some disadvantages in traditional treatment to amblyopia, such as poor compliance, easily leading to the healthy eye eyesight problem, the poor recovery of binocular and stereoscopy vision, etc. This paper put forward a new individual amblyopia treatment system to solve these problems. It combined pattern reversal visual evoked potential (P_VEP) feedback and dichoptic training theory and then developed the EEG data acquisition and synchronized trigger circuit using and I/O data collecting card, realized the raw EEG signal real-time sampling, extracted VEP waveform from the raw EEG data by using digital filtering algorithm, average superposition algorithm and wavelet an lgorithm, finally, the latency and peak of P_VEP wave shape were accurately measured. This system also present an individual treatment solution based on dichoptic training model by searching and obtaining the best spatial frequency of the treatment training picture and combining with 3D display technology.

Evaluation of the Role of Monocular Video Game Play as an Adjuvant to Occlusion Therapy in the Management of Anisometropic Amblyopia

PURPOSE

To evaluate the role of monocular video game play as an adjuvant to occlusion therapy in the treatment of anisometropic amblyopia.

METHODS

In a prospective randomized study design, 68 children with ages ranging from 6 to 14 years who had anisometropic amblyopia with a best corrected visual acuity (BCVA) in the amblyopic eye of better than 6/36 and worse than 6/12 and no manifest strabismus were recruited. They were randomly allocated into two groups: 34 children received 1 hour per day of video game play for the first month plus 6 hours per day of occlusion therapy (video game and occlusion group) and 34 children received 6 hours per day of occlusion therapy alone (occlusion only group). Patients were then evaluated at baseline and 1 and 3 months after treatment for BCVA, stereoacuity, and contrast sensitivity.

RESULTS

In the video game and occlusion group, BCVA improved from 0.61 ± 0.12 logarithm of the minimum angle of resolution (logMAR) at baseline to 0.51 ± 0.14 logMAR (P = .001) at 1 month and 0.40 ± 0.15 logMAR (P = .001) at 3 months. In the occlusion only group, BCVA improved from 0.65 ± 0.09 logMAR at baseline to 0.60 ± 0.10 logMAR (P = .001) at 1 month and 0.48 ± 0.10 logMAR (P = .001) at 3 months. There was significantly more improvement in the video game and occlusion group compared to the occlusion only group (P = .003 at 1 month and P = .027 at 3 months).

CONCLUSIONS

Video game play plus occlusion therapy enhances the visual recovery in anisometropic amblyopia. [J Pediatr Ophthalmol Strabismus. 2017;54(4):244-249.].

Amblyopia treatment of adults with dichoptic training using the virtual reality oculus rift head mounted display: preliminary results

BACKGROUND

The gold standard treatments in amblyopia are penalizing therapies, such as patching or blurring vision with atropine that are aimed at forcing the use of the amblyopic eye. However, in the last years, new therapies are being developed and validated, such as dichoptic visual training, aimed at stimulating the amblyopic eye and eliminating the interocular supression.

PURPOSE

To evaluate the effect of dichoptic visual training using a virtual reality head mounted display in a sample of anisometropic amblyopic adults and to evaluate the potential usefulness of this option of treatment.

METHODS

A total of 17 subjects (10 men, 7 women) with a mean age of 31.2 years (range, 17-69 year) and anisometropic amblyopia were enrolled. Best corrected visual acuity (BCVA) and stereoacuity (Stereo Randot graded circle test) changes were evaluated after 8 sessions (40 min per session) of dichoptic training with the computer game Diplopia Game (Vivid Vision) run in the Oculus Rift OC DK2 virtual reality head mounted display (Oculus VR).

RESULTS

Mean BCVA in amblyopic eye improved significantly from a logMAR value of 0.58 ± 0.35 before training to a post-training value of 0.43 ± 0.38 (p < 0.01). Forty-seven percent of the participants achieved BCVA of 20/40 or better after the training as compared to 30% before the training. Mean stereoacuity changed from a value of 263.3 ± 135.1 before dichoptic training to a value of 176.7 ± 152.4 s of arc after training (p < 0.01). A total of 8 patients (47.1%) before dichoptic treatment had unmeasurable stereoacuity while this only occurred in 2 patients (11.8%) after training.

CONCLUSIONS

Dichoptic training using a virtual reality head mounted display seems to be an effective option of treatment in adults with anisometropic amblyopia. Future clinical trials are needed to confirm this preliminary evidence.

TRIAL REGISTRATION

Trial ID: ISRCTN62086471 . Date registered: 13/06/2017. Retrospectively registered.

A PC-based shutter glasses controller for visual stimulation using multithreading in LabWindows/CVI

BACKGROUND AND OBJECTIVES

Amblyopia, commonly known as "lazy eye," is poor vision in an eye from prolonged neurologic suppression. It is a major public health problem, afflicting up to 3.6% of children, and will lead to lifelong visual impairment if not identified and treated in early childhood. Traditional treatment methods, such as occluding or penalizing the good eye with eye patches or blurring eye drops, do not always yield satisfactory results. Newer methods have emerged, based on liquid crystal shutter glasses that intermittently occlude the better eye, or alternately occlude the two eyes, thus stimulating vision in the "lazy" eye. As yet there is no technology that allows easy and efficient optimization of the shuttering characteristics for a given individual. The purpose of this study was to develop an inexpensive, computer-based system to perform liquid crystal shuttering in laboratory and clinical settings to help "wake up" the suppressed eye in amblyopic patients, and to help optimize the individual shuttering parameters such as wave shape, level of transparency/opacity, frequency, and duty cycle of the shuttering.

METHODS

We developed a liquid crystal glasses controller connected by USB cable to a PC computer. It generates the voltage waveforms going to the glasses, and has potentiometer knobs for interactive adjustments by the patient. In order to achieve good timing performance in this bidirectional system, we used multithreading programming techniques with data protection, implemented in LabWindows/CVI.

RESULTS

The hardware and software developed were assessed experimentally. We achieved an accuracy of ±1Hz for the frequency, and ±2% for the duty cycle of the occlusion pulses. We consider these values to be satisfactory for the purpose of optimizing the visual stimulation by means of shutter glasses. The system can be used for individual optimization of shuttering attributes by clinicians, for training sessions in clinical settings, or even at home, aimed at stimulating vision in the "lazy" eye.

CONCLUSIONS

Multithreading offers significant benefits for data acquisition and instrument control, making it possible to implement time-efficient algorithms in inexpensive yet versatile medical instrumentation with only minimum requirements on the hardware.

Elbow splinting as a method to increase patching compliance in amblyopia therapy

PurposeThe purpose of the study was to evaluate the feasibility and acceptability of utilizing elbow splints as a method of increasing amblyopic patching compliance in pediatric ophthalmology patients who fail to comply with prescribed patching regimens.Patients and methodsPatients <6 years of age who were not adhering to pre-specified patching guidelines were prescribed elbow splints in order to increase patching compliance at the discretion of a pediatric ophthalmologist. If the child was non-compliant (patching <50% of specified time or consistently removing patch), parents were asked to try using the elbow splints until patching compliance was achieved. Non-parametric Wilcoxon signed-rank tests were used to compare patching time pre- and post-splints.Results41/48 children who were prescribed elbow splints to increase patching compliance for amblyopia were included for analysis. Seven children were excluded due to patching and splints being prescribed at the outset (n=4), and for not using the splinting intervention (n=3). Median age at being prescribed elbow splints was 37 (12-68) months. Mean daily patching prior to splints was 1.5±1.7 h, whereas mean prescribed daily patching was 4.95±1.5 h. Following splinting, 34/41 (83%) became compliant with patch alone, and visual acuity increased in 39/41 (95%) patients, with no patients developing amblyopia in the fellow eye. Median amount of time splints was required to improve compliance was 7 (1-240) days.ConclusionElbow splinting seems to be a viable alternative method to increase pediatric amblyopic patching compliance when patching alone fails to achieve satisfactory compliance.

Training to improve contrast sensitivity in amblyopia: correction of high-order aberrations

Perceptual learning is considered a potential treatment for amblyopia even in adult patients who have progressed beyond the critical period of visual development because adult amblyopes retain sufficient visual plasticity. When perceptual learning is performed with the correction of high-order aberrations (HOAs), a greater degree of neural plasticity is present in normal adults and those with highly aberrated keratoconic eyes. Because amblyopic eyes show more severe HOAs than normal eyes, it is interesting to study the effects of HOA-corrected visual perceptual learning in amblyopia. In the present study, we trained twenty-six older child and adult anisometropic amblyopes while their HOAs were corrected using a real-time closed-loop adaptive optics perceptual learning system (AOPL). We found that adaptive optics (AO) correction improved the modulation transfer functions (MTFs) and contrast sensitivity functions (CSFs) of older children and adults with anisometropic amblyopia. When perceptual learning was performed with AO correction of the ocular HOAs, the improvements in visual function were not only demonstrated in the condition with AO correction but were also maintained in the condition without AO correction. Additionally, the learning effect with AO correction was transferred to the untrained visual acuity and fellow eyes in the condition without AO correction.

Quantitative Analysis of the Effects of a Bangerter Filter on Gross Stereopsis in Experimental Models of Reduced Visual Acuity

Although a 0.3 Bangerter filter, which reduces visual acuity, is frequently used for treating moderate amblyopia, the effects on gross stereopsis are not well known. This study quantitatively evaluated whether gross stereopsis is degraded by a Bangerter filter. Seven healthy subjects (median age: 29 years) participated in this psychophysical study. Targets with crossed disparities of 1°, 2°, 3°, 4°, and 5° were randomly presented on a three-dimensional television display. The subjects indicated the point at which the targets popped out from the television screen (matching method). The distance from the screen to the point was defined as the degree of stereopsis. This experiment was performed with and without a 0.3 Bangerter filter. The corrected monocular visual acuities were decreased to about 20/63 by the filter in all subjects. No significant difference was observed for any of the disparities (1°-5°), between the degree of stereopsis visualized with and without filters for either the dominant or the non-dominant eye. The degree of stereopsis was not degraded by the reduced visual acuity induced by the use of 0.3 Bangerter filters. In this regard, the use of 0.3 Bangerter filters may be considered safer than occlusion eye patches for the patients with normal binocular vision.

A pilot randomized clinical trial of intermittent occlusion therapy liquid crystal glasses versus traditional patching for treatment of moderate unilateral amblyopia

PURPOSE

To compare the effectiveness of intermittent occlusion therapy (IO therapy) using liquid crystal glasses and continuous occlusion therapy using traditional adhesive patches for treating amblyopia.

METHODS

Children 3-8 years of age with previously untreated, moderate, unilateral amblyopia (visual acuity of 20/40 to 20/100 in the amblyopic eye) were enrolled in this randomized controlled trial. Amblyopia was associated with strabismus, anisometropia, or both. All subjects had worn any optimal refractive correction for at least 12 weeks without improvement. Subjects were randomized into two treatment groups: a 4-hour IO therapy group with liquid crystal glasses (Amblyz), set at 30-second opaque/transparent intervals (occluded 50% of wear time), and a 2-hour continuous patching group (occluded 100% of wear time). For each patient, visual acuity was measured using ATS-HOTV before and after 12 weeks of treatment.

RESULTS

Data from 34 patients were available for analysis. Amblyopic eye visual acuity improvement from baseline was 0.15 ± 0.12 logMAR (95% CI, 0.09-0.15) in the IO therapy group (n = 19) and 0.15 ± 0.11 logMAR (95% CI, 0.1-0.15) in the patching group (n = 15). In both groups improvement was significant, but the difference between groups was not (P = 0.73). No adverse effects were reported.

CONCLUSIONS

In this pilot study, IO therapy with liquid crystal glasses is not inferior to adhesive patching and is a promising alternative treatment for children 3-8 years of age with moderate amblyopia.

[Dichoptic training for amblyopia]

Dichoptic training is a promising new therapeutic approach to amblyopia, which employs simultaneous and separate stimulation of both eyes (thus dichoptic). The contrast for the good eye is reduced thus aiming at a balance with the amblyopic eye. In contrast to monocular patching, binocular vision is trained by video game tasks that can only be solved binocularly. To date the average gain in visual acuity achieved in currently available studies is only 0.20 ± 0.07 logMAR and is not significantly better than competing treatment options. This article explains the basic approach of dichoptic training, summarizes pertinent studies, names unsolved problems and closes with a personal critical assessment.

[Occlusion treatment for amblyopia. Age dependence and dose-response relationship]

BACKGROUND

Based on clinical experience and studies on animal models the age of 6-7 years was regarded as the limit for treatment of amblyopia, although functional improvement was also occasionally reported in older patients. New technical developments as well as insights from clinical studies and the neurosciences have attracted considerable attention to this topic.

OBJECTIVE

Various aspects of the age dependence of amblyopia treatment are discussed in this article, e. g. prescription, electronic monitoring of occlusion dosage, calculation of indicators for age-dependent plasticity of the visual system, and novel, alternative treatment approaches.

METHODS

Besides a discussion of the recent literature, results of studies by our "Child Vision Research Unit" in Frankfurt are presented: results of a questionnaire about prescription habits concerning age limits of patching, electronic recording of occlusion in patients beyond the conventional treatment age, calculation of dose-response function and efficiency of patching and their age dependence.

RESULTS

The results of the questionnaire illustrate the uncertainty about age limits of prescription with significant deviations from the guideline of the German Ophthalmological Society (DOG). Electronic recording of occlusion allowed the quantification of declining dose-response function and treatment efficiency between 5 and 16 years of age. Reports about successful treatment with conventional and novel methods in adults are at variance with the notion of a rigid adult visual system lacking plasticity.

CONCLUSION

Electronic recording of patching allowed new insights into the age-dependent susceptibility of the visual system and contributes to a more evidence-based treatment of amblyopia. Alternative approaches for adults challenge established notions about age limits of amblyopia therapy. Further studies comparing different treatment options are urgently needed.

The Use of a Mobile Van for School Vision Screening: Results of 63 841 Evaluations

PURPOSE

To present data from an established mobile screening program for children in the amblyogenic age group using gold-standard examination techniques by eye care professionals.

DESIGN

Retrospective 12-year, cross-sectional study.

METHODS

setting: Single center.

STUDY POPULATION

All children enrolled in pre-kindergarten, kindergarten, and first grades in public schools in Cleveland, Ohio were eligible for evaluations. intervention procedure: An ophthalmic technician and/or optometrist examined children in a customized van that visits all elementary schools. The initial screening included testing of monocular near and distance visual acuity, stereoacuity, ocular alignment, motility, pupils, and external abnormalities. Children meeting the 2003 American Academy of Pediatrics vision screening referral criteria underwent cycloplegic retinoscopy and ophthalmoscopy by the on-site optometrist and received glasses. In addition, these children were referred to pediatric ophthalmology for ongoing care.

MAIN OUTCOME MEASURE

Determination of the proportion of children with refractive errors, amblyopia, and/or strabismus.

RESULTS

Between 2002 and 2014, 63 841 evaluations were performed, representing approximately 55% of eligible children. Overall, 6386 (10.0%) of children met 1 or more referral criteria: 5355 (8.39%) received glasses, 873 (1.37%) had amblyopia, and 1125 (1.76%) had strabismus. Over the 12-year period, there was no statistically significant change in the prevalence of strabismus (1.73%-2.24%, P = .91) or amblyopia (0.9%-2.08%, P = .13) among first grade students.

CONCLUSIONS

Amblyopia, strabismus, and refractive errors are common in young children. During the study period, the rates of amblyopia and strabismus remained stable, indicating the need for continued vision screening and treatment services. A van-based model, traveling directly to schools, appears to be effective in reaching young children in underserved communities.

Amblyopia in children (aged 7 years or less)

INTRODUCTION

Amblyopia is reduced visual acuity not immediately correctable by glasses, in the absence of ocular pathology. It is commonly associated with squint (strabismus) or refractive errors resulting in different visual inputs to each eye during the sensitive period of visual development (aged <7-8 years). The cumulative incidence is estimated at 2% to 4% in children aged up to 7 years.

METHODS AND OUTCOMES

We conducted a systematic overview, aiming to answer the following clinical question: What are the effects of medical treatments for amblyopia in children aged 7 years or less? We searched: Medline, Embase, The Cochrane Library, and other important databases up to January 2014 (Clinical Evidence overviews are updated periodically; please check our website for the most up-to-date version of this overview).

RESULTS

At this update, searching of electronic databases retrieved 70 studies. After deduplication and removal of conference abstracts, 51 records were screened for inclusion in the overview. Appraisal of titles and abstracts led to the exclusion of 37 studies and the further review of 14 full publications. Of the 14 full articles evaluated, two systematic reviews were updated and three RCTs and two follow-up studies were added at this update. We performed a GRADE evaluation for nine PICO combinations.

CONCLUSIONS

In this systematic overview we categorised the efficacy for three interventions, based on information about the effectiveness and safety of glasses, occlusion, or penalisation with atropine.