Longstanding effects of continuous theta burst stimulation in adult amblyopes

CLINICAL RELEVANCE

Continuous theta burst stimulation may be an important tool in the therapeutic management of amblyopia, when trying to correct the established neuronal imbalance. It is important to understand whether two sessions of continuous theta burst stimulation produce greater and longstanding changes in visual acuity and suppressive imbalance than one session of continuous theta burst stimulation.

BACKGROUND

We hypothesise that through the usage of continuous theta burst stimulation (cTBS) it is possible to change cortical excitability in a situation where visual impairment is present.

METHODS

We selected 22 adult amblyopes, 18 females and 4 males, with an age range of 20-59 years. They were randomised into two groups: group A with 10 amblyopes was submitted to one session of cTBS and group B with 12 amblyopes submitted to two sessions of cTBS. Visual acuity (VA) and suppressive imbalance (SI) were evaluated immediately before and after stimulation in both groups A and B. A follow-up was done in both groups.

RESULTS

For both group A and B, the VA improvements were significant after cTBS (p = 0.005 and p = 0.003, respectively). Regarding SI, both group A and B had significant improvements after cTBS (p = 0.03 and p = 0.005, respectively). Comparing groups, A and B no significant differences were found with regard to the results obtained both for VA (p = 0.72) and SI (p = 0.24). However, significant differences were found between group A and B with regard to the duration of stimulation effect for VA (p = 0.049) and SI (p = 0.03).

CONCLUSION

We conclude that two sessions of cTBS do not produce better results than one session of stimulation. However, it seems that two sessions of cTBS produce longstanding effects in VA and SI.

Management of Contact Lenses and Visual Development in Pediatric Aphakia

Congenital cataract is among the main causes of treatable vision loss in childhood. The first weeks and months of life are a critical time for the development of vision. Therefore, early cataract surgery and effective multifaceted treatment of the resulting aphakia in the early stages of life are of great value for the management of vision development. Among the treatment models, contact lenses (CL) have an important place in infancy and early childhood up to the age of 2 years. Although good visual gains were not considered very likely, especially in unilateral aphakia, important steps have been taken in the treatment of pediatric aphakia thanks to the surgical techniques developed over time and the increasing experience with optical correction systems, especially CLs. This review examines current developments in the types of CL used in pediatric aphakia, their application features, comparison with other optical systems, the features of amblyopia treatment in the presence of CL, and the results obtained with family compliance to CL wear and occlusion therapy in the light of existing studies.

Treatment rate of strabismus and amblyopia is associated with the location of pediatric ophthalmologists in the United States

PURPOSE

To determine whether the geographic density of pediatric ophthalmologists is associated with the rate of children treated for strabismus and amblyopia.

METHODS

This cross-sectional study included children treated for strabismus and amblyopia 0-17 years of age with commercial insurance who were included in the Vision and Eye Health Surveillance System. Additionally, pediatric ophthalmologists by state were determined using the American Association for Pediatric Ophthalmology and Strabismus website. Unadjusted linear regression was used to compare the geographic density of pediatric ophthalmologists and the rate of children treated for strabismus and amblyopia by state in 2016. This was repeated using multivariable linear regression, controlling for race, poverty, non-English-speaking children, and insurance coverage for children by state.

RESULTS

New York and Mississippi had the highest and lowest rates of treatment of strabismus and amblyopia, with 3.97 and 0.83 children treated per 100 children, respectively. The geographic density of pediatric ophthalmologists was associated with the rate of children treated for strabismus and amblyopia in unadjusted analyses (β = 0.62, P < 0.001). Further, the geographic density of pediatric ophthalmologists was associated with the rate of children treated for strabismus and amblyopia in adjusted analyses (β = 0.61, P < 0.001).

CONCLUSIONS

The geographic density of pediatric ophthalmologists by state was positively associated with the rate of children treated for strabismus and amblyopia.

Retinal microvascular changes in unilateral functional amblyopia detected by oct-angiography and follow-up during treatment

OBJECTIVE

To evaluate the macular microvascular changes using optical coherence tomographic angiography (OCT-A) in children with unilateral amblyopia and their reversibility during treatment.

METHODS

Patients with unilateral strabismic or anisometropic amblyopia or residual amblyopia from early congenital cataract surgery, examined between October 2019 and March 2021, were included. Vessel density and perfusion density in the superficial capillary plexus and area, perimeter and circularity of the foveal avascular zone (FAZ) were analysed using OCT-A in amblyopic eyes, contralateral eyes and control group healthy eyes. Correlation analyses between the microvascular parameters and the visual acuity were performed. In a pilot study on a few patients from the amblyopic cohort, longitudinal follow-up during treatment was also performed.

RESULTS

A total of 128 eyes of 64 patients were included: 32 amblyopic eyes compared with 32 contralateral eyes and 64 control eyes. Vessel density and perfusion density in the superficial capillary plexus were significantly lower in amblyopic eyes compared to control eyes in 6 × 6 mm (p < 0.02) and 3 × 3 mm (p < 0.01) scans. Correlation analyses showed a linear decrease in vessel density and perfusion density with decreasing visual acuity. The microvascular changes observed were reversible with the occlusion treatment of amblyopia (p < 0.001).

CONCLUSIONS

The study found a decrease in vessel density and perfusion density in the macula of children with unilateral functional amblyopia. These microvascular changes were correlated with visual acuity and appeared to be reversible with treatment of amblyopia. On the whole, OCT-A appears to be a relevant complementary examination when it comes to diagnosing and monitoring functional amblyopia.

Assessment of the Responses of the Artificial Intelligence-based Chatbot ChatGPT-4 to Frequently Asked Questions About Amblyopia and Childhood Myopia

PURPOSE

To assess the responses of the ChatGPT-4, the forerunner artificial intelligence-based chatbot, to frequently asked questions regarding two common pediatric ophthalmologic disorders, amblyopia and childhood myopia.

METHODS

Twenty-seven questions about amblyopia and 28 questions about childhood myopia were asked of the ChatGPT twice (totally 110 questions). The responses were evaluated by two pediatric ophthalmologists as acceptable, incomplete, or unacceptable.

RESULTS

There was remarkable agreement (96.4%) between the two pediatric ophthalmologists on their assessment of the responses. Acceptable responses were provided by the ChatGPT to 93 of 110 (84.6%) questions in total (44 of 54 [81.5%] for amblyopia and 49 of 56 [87.5%] questions for childhood myopia). Seven of 54 (12.9%) responses to questions on amblyopia were graded as incomplete compared to 4 of 56 (7.1%) of questions on childhood myopia. The ChatGPT gave inappropriate responses to three questions about amblyopia (5.6%) and childhood myopia (5.4%). The most noticeable inappropriate responses were related to the definition of reverse amblyopia and the threshold of refractive error for prescription of spectacles to children with myopia.

CONCLUSIONS

The ChatGPT has the potential to serve as an adjunct informational tool for pediatric ophthalmology patients and their caregivers by demonstrating a relatively good performance in answering 84.6% of the most frequently asked questions about amblyopia and childhood myopia. [J Pediatr Ophthalmol Strabismus. 2024;61(2):86-89.].

Amblyopia Care Trends Following Widespread Photoscreener Adoption

Importance

Amblyopia can result in permanent vision loss if not properly treated before age 7 years. In 2017, the US Preventive Services Task Force recommended that vision screening should occur at least once in all children aged 3 to 5 years to detect amblyopia.

Objective

To understand trends and factors associated with screening, referral, or diagnosis of amblyopia before and after photoscreening expansion across a relatively large health care system in late 2017.

Design, Setting, and Participants

This is a retrospective cohort study of electronic health record data from patients with a well child care visit at approximately age 3 years (ages 2.75-3.25 years) in a relatively large, multispecialty group practice in Northern California and linked census data between 2015 and 2022. Data were extracted and analyzed from October 2022 through August 2023.

Exposures

Patient sex, race and ethnicity, immunization records, previous well child care visits, and census-level median household income.

Main Outcomes and Measures

Vision screening, pediatric ophthalmology referral, or amblyopia diagnosis, compared using adjusted odds ratios (AORs).

Results

The study included 2015-2017 data from 23 246 patients aged 3 years with at least 1 well child care visit (11 206 [48.2%] female) compared with 2018-2022 postexpansion data from 34 281 patients (16 517 [48.2%] female). The screening rate increased from 5.7% (424 of 7505) in 2015 to 72.1% (4578 of 6354) in 2022. The referral rate increased from 17.0% (1279 of 7505) in 2015 to 23.6% (1836 of 7792) in 2018. The diagnosis rate was 2.7% (200 of 7505) in 2015, peaked at 3.4% (263 of 7792) in 2018, and decreased to 1.4% (88 of 6354) in 2022. Compared with White patients, patients who were Asian, Black, or Hispanic were less likely to be screened (Asian: AOR, 0.80; 95% CI, 0.72-0.88; Black: AOR, 0.71; 95% CI, 0.53-0.96; Hispanic: AOR, 0.88; 95% CI, 0.80-0.97). Compared with White patients, patients who were Asian or Hispanic were more likely to be referred (Asian: AOR, 1.49; 95% CI, 1.36-1.62; Hispanic: AOR, 1.32; 95% CI, 1.18-1.48) and were more likely to be diagnosed (Asian: AOR, 1.29; 95% CI, 1.07-1.56; Hispanic: AOR, 1.67; 95% CI, 1.33-2.11).

Conclusions and Relevance

In this study, increased availability of photoscreeners was associated with an increase in overall rates of vision screening for children aged 3 years in a relatively large health care system. Given that US rates of visual impairment are predicted to increase, additional targeted interventions would be needed to address remaining disparities in amblyopia care along patient- and clinician-level factors.

Effects of acupuncture on vision and visual function in children with anisometropic amblyopia

OBJECTIVES

To observe the clinical efficacy of Tiaoqi Tongjing Mingmu acupuncture (acupuncture for regulating qi, unblocking meridians and brightening eyes) combined with conventional treatment for anisometropic amblyopia children.

METHODS

A total of 76 children with monocular anisometropic amblyopia were randomized into an observation group (38 cases, 2 cases dropped out) and a control group (38 cases). The lens covering therapy was adopted in both groups. The conventional treatment i.e. red flash, grating and visual stimulation was given in the control group, 5 min for one item each time; on the basis of the treatment in the control group, acupuncture was applied at bilateral Jingming (BL 1), Cuanzhu (BL 2), Fengchi (GB 20) and Guangming (GB 37) in the observation group. Both groups were treated once every other day, 3 times a week for 4 weeks. Before and after treatment, the best corrected visual acuity, the latency and amplitude of P100 wave of pattern visual evoked potential (P-VEP), the diopter (spherical equivalent [SE]) were observed, the stereoacuity was measured by Titmus stereoscopic examination, and the clinical efficacy was evaluated in both groups.

RESULTS

Compared with those before treatment, the best corrected visual acuity improved (P<0.05), the latency of P-VEP P100 wave was shortened and the amplitude of P-VEP P100 wave was increased (P<0.05), and the SE and Titmus values were decreased (P<0.05) after treatment in both groups. After treatment, in the observation group, the best corrected visual acuity was higher (P<0.05), the latency of P-VEP P100 wave was shorter and the amplitude of P-VEP P100 wave was higher (P<0.05), SE and Titmus values were lower (P<0.05) than those in the control group. The total effective rate was 86.1% (31/36) in the observation group, which was superior to 65.8% (25/38) in the control group (P<0.05).

CONCLUSIONS

During the visual plasticity period, Tiaoqi Tongjing Mingmu acupuncture combined with conventional treatment can effectively improve the best corrected vision, diopter and stereoacuity in children with anisometropic amblyopia, and enhance the nerve conduction function from retina to visual cortex. Its effect is superior to that of simple conventional treatment.

Effects of grating stimulation on vision in individuals with amblyopia: a systematic review and meta-analysis

PURPOSE

To investigate the effects of Cambridge Stimulator with grating element stimulation on visual acuity (VA), grating acuity (GA), and contrast sensitivity (CS) in patients with amblyopia.

METHODS

Three electronic databases (PubMed, Embase, and Cochrane Library) were searched for studies published from January 1970 to November 2022. The searched studies were reviewed and extracted independently by two authors. The included studies were evaluated by the Cochrane risk of bias. A meta-analysis calculating Hedges' g effect-size metric with 95% confidence intervals using random-effects DerSimonian-Laird model was employed. Heterogeneity was estimated using I2 statistics. Outcomes of interest included VA, GA, and CS.

RESULTS

A total of 1221 studies were identified. Twenty-four studies including 900 subjects met the inclusion criteria. The outcome measure of all visual indexes (VA: Hedges' g of - 0.43, 95% CI =  - 0.81 to - 0.05, I2 = 86%, p = 0.02; GA: Hedges' g of 3.79, 95% CI = 1.05 to 6.54, I2 = 98%, p = 0.01; CS: Hedges' g of 0.64, 95% CI = 0.19 to 1.09, I2 = 41%, p = 0.00) significantly favored in the grating group.

CONCLUSIONS

Grating stimulation may be a positive help for visual functions in patients with amblyopia. The effects of grating stimulation on VA and CS appear to be opposite. This study is registered with www.crd.york.ac.uk/prospero/ (CRD42022366259).

Supervised dichoptic gaming versus monitored occlusion therapy for childhood amblyopia: Effectiveness and efficiency

PURPOSE

To compare the effectiveness and efficiency of supervised dichoptic action-videogame play to occlusion therapy in children with amblyopia.

METHODS

Newly diagnosed children with amblyopia aged 4-12 years were recruited, excluding strabismus >30PD. After 16 weeks of refractive adaptation children were randomized to gaming 1 h/week supervised by the researcher, or electronically monitored occlusion 2 h/day. The gaming group played a dichoptic action-videogame using virtual reality goggles, which included the task of catching a snowflake presented intermittently to the amblyopic eye. Contrast for the fellow eye was self-adjusted until 2 identical images were perceived. The primary outcome was visual acuity (VA) change from baseline to 24 weeks.

RESULTS

We recruited 96 children, 29 declined and 2 were excluded for language or legal issues. After refractive adaptation, 24 of the remaining 65 no longer met the inclusion criteria for amblyopia, and 8 dropped out. Of 16 children treated with gaming, 7 (6.7 years) completed treatment, whereas 9 younger children (5.3 years) did not. Of 17 treated with occlusion, 14 (5.1 years) completed treatment and 3 (4.5 years) did not. Of 5 children with small-angle strabismus, 3 treated with occlusion completed treatment and 2 treated with gaming did not. Median VA improved by 0.30 logMAR (IQR 0.20-0.40) after gaming, 0.20 logMAR (0.00-0.30) after occlusion (p = 0.823). Treatment efficiency was 1.25 logMAR/100 h (range 0.42-2.08) with gaming, 0.08 (-0.19-0.68) with occlusion (p < 0.001).

CONCLUSION

Dichoptic gaming seems a viable alternative for older children with refractive amblyopia after glasses adaptation. Treatment efficiency with gaming under continuous supervision was 15 times higher than with occlusion at home.

Randomized Controlled Trial of Patching versus Dichoptic Stimulation Using Virtual Reality for Amblyopia Therapy

Purpose: To compare the outcomes of patching to dichoptic stimulation using virtual reality (VR) in moderate and severe amblyopia.Methods: This study was conducted on 86 subjects with unilateral anisometropic and mixed amblyopia. The subjects were randomized to the VR or patching group. The VR group received treatment using the Vivid Vision software (Vivid Vision Inc., San Francisco, USA) with each subject receiving weekly 2 h-sessions for 10 weeks. The patching group was prescribed patching for 10 weeks. Best-corrected visual acuity (BCVA) was measured using a single crowded letter in an ETDRS chart before, after 10 weeks of treatment, and after another 10 weeks of cessation of treatment. Near stereoacuity was measured using the TNO test.Results: Forty-two patients were randomized to the patching group and 44 to the VR group. The median age of the subjects was 12.0 (range 6.0 to 37.0) years. In the VR group, mean amblyopic eye BCVA showed statistically significant improvement by 0.89 line (95% confidence interval {CI}, 0.73 to 1.35 lines; p < 0.001) after 10 weeks of therapy, and after another 10 weeks of follow-up by 1.32 lines from baseline (95% CI, 1.15 to 1.7 lines; p < 0.001). Regarding the patching group, mean BCVA showed statistically significant improvement after 10 weeks by 1.38 lines (95% CI, 0.82 to 1.8 lines; p < 0.001), and after another 10 weeks by 1 line from baseline (95% CI, 0.06-0.147; 0.6 to 1.47 lines; p < 0.001). There was no significant difference between both groups at any time-point (p values >0.05). No serious adverse events were noted. Adults and severe amblyopes in the VR group showed more significant VA improvement than their counterparts in the patching group.Conclusions: Amblyopes treated using VR dichoptic treatment demonstrated statistically significant VA improvement after 10 and 20 weeks of follow-up that is comparable to patching.

[Paying attention to the application of contact lenses in the treatment of special types of refractive abnormalities in children]

Childhood vision is in the stage of development, and the incidence of ametropia is high. For special types of refractive abnormalities such as ultra-high myopia, ultra-high anisometropia and aphakia, conventional wearing of frame glasses can easily cause aberrations and peripheral visual deformations, affect the visual development of children, and even cause refractory amblyopia. In this article, the benefits of contact lenses are discussed from perspectives of ultra-high refractive error, refraction-related refractory amblyopia, and photosensitivity-related refractive error, so as to attract the attention of clinical physicians, expand the application scope of contact lens wear, give full play to the role of contact lenses, and improve the diagnosis and treatment of refractive abnormalities in children.

Perceptual Learning Based on the Lateral Masking Paradigm in Anisometropic Amblyopia With or Without a Patching History

Purpose

Perceptual learning (PL) has shown promising performance in restoring visual function in adolescent amblyopes. We retrospectively compared the effect of a well-accepted PL paradigm on patients with anisometropic amblyopia with or without a patching therapy history (patching therapy [PT] group versus no patching therapy [NPT] group).

Methods

Eighteen PT and 13 NPT patients with anisometropic amblyopia underwent monocular PL for 3 months. During training, patients practiced a Gabor detection task following the lateral masking paradigm by applying a temporal two-alternative forced choice procedure with the amblyopic eye. Monocular contrast sensitivity functions (CSF), visual acuity, interocular differences in visual function metrics, and stereoacuity were compared before and after training.

Results

PL improved the visual acuity of the amblyopia eyes by 0.5 lines on average in the PT group and 1.5 lines in the NPT group. A significant reduction in the interocular difference in visual acuity was observed in the NPT group (P < 0.01) but not in the PT group (P = 0.05). Regarding CSF metrics, the area under the log CSF and cutoff in the amblyopic eyes of the NPT groups increased after training (P < 0.05). In addition, the interocular differences of the CSF metrics (P < 0.05) in the NPT group were significantly reduced. However, in the PT group, all the CSF metrics were unchanged after training. A total of 27 of 31 patients in both groups had no measurable stereopsis pretraining, and recovery after training was not significant.

Conclusions

PL based on a lateral masking training paradigm improved visual function in anisometropic amblyopia. Patients without a patching history achieved greater benefits.

Translational Relevance

PL based on a lateral masking training paradigm could be a new treatment for amblyopia.

Assessment of amblyopic children undergoing occlusion therapy by pattern visual evoked potentials and contrast sensitivity tests

Background: Amblyopia is a case where one or less commonly, both eyes have impaired visual performance, even with the best optical correction and no visible disease of the visual system. Objectives: To assess contrast sensitivity tests (CST) and pattern visual evoked potentials (PVEP) results in amblyopic children who have already started occlusion therapy for durations ranging from 6 to 12 months. Methods: This cross-sectional study was conducted on 200 eyes of 50 patients with monocular amblyopia and 50 age and sex matched controls. Both patients and controls underwent ophthalmological assessment, PVEP, and CST. Results: There was no statistically significant difference in the results of P100 latencies of qualitative PVEP in amblyopic eyes compared to non-amblyopic eyes and control eyes, while the qualitative CST showed a highly statistically significant difference, being affected in 98% of amblyopic eyes compared to unaffected eyes (4%) and control eyes (4%). The maximum contrast level and minimal contrast level of quantitative CST were significantly lower in amblyopic eyes compared to non-amblyopic and control eyes. The cutoff value of maximal contrast level at mean frequencies of 2.5 ± 0.9 Hz, and a range of (1.1-4.1) for amblyopic eyes is ≤21 dB, while the cutoff value of minimal contrast level at mean frequencies of 13.4 ± 2.6 Hz, and a range of (6.7-18) for amblyopic eyes is ≤12 dB. Conclusion: Detection of amblyopia by CST is a noninvasive and easy procedure, which represents a promising tool to support the diagnosis of amblyopia.

[The effect of pleoptic treatment on the stability of visual fixation in children and adolescents with amblyopia of various degrees]

PURPOSE

This study assesses the effect of pleoptic treatment on the stability of visual fixation in children and adolescents with amblyopia of various degrees.

MATERIAL AND METHODS

The effect of the treatment in 35 children (35 eyes) with amblyopia of various degrees was evaluated using the MP-1 Microperimeter. The stability was determined by two criteria - number of fixation point hits in the 2° zone and the width of the field of fixation. Children underwent a standard course of treatment.

RESULTS

There was an improvement in the stability of visual fixation after treatment. The number of fixation point hits in the 2° zone increased from 44.8±4.1% to 52.6±3.8%. At the same time, the width of the field of fixation after treatment decreased from 6.5±0.7° to 5.2±0.5°. Visual acuity with correction in children with amblyopia correlates with the number of fixation point hits in the 2° zone (direct high correlation "+0.7") and width of the field of fixation (inverse high correlation "-0.7") both before and after the treatment.

CONCLUSION

Stabilization of visual fixation was observed in patients with amblyopia of varying degrees after the pleoptic treatment.

Late Recurrence of Anisometropic Amblyopia

A 15-year-old boy whose anisometropic amblyopia was effectively treated with glasses was examined. Despite years of stability, his visual acuity decreased from 20/20 to 20/60 with poor glasses compliance. Although amblyopia recurrence is well recognized, this case emphasizes potential late recurrence after prolonged success. Fortunately, he improved to 20/20 after improved compliance. [J Pediatr Ophthalmol Strabismus. 2024;61(1):e11-e12.].

Impact of active vision therapy compared to conventional patching therapy on visual acuity and stereoacuity in children with amblyopia

PURPOSE

To compare improvements in visual acuity (VA) and stereoacuity between active vision therapy (AVT) and conventional patching therapy in children with amblyopia.

METHODS

This study included 65 children aged 5 to 16 years (mean age±SD, 11.00±3.29 years) with unilateral amblyopia. Among them, 31 children underwent active vision therapy (AVT group), and 34 children underwent conventional patching therapy (patching group). AVT group underwent three sequential phases of AVT: Monocular phase (pursuit, saccades, fixation, visuomotor, eye-hand coordination, and central peripheral activities), biocular phase (diplopia awareness, antisuppression, monocular fixation in a binocular field, accommodative activities, bilateral integration, and fine motor activities) and binocular phase (fusion and stereopsis). Patching group patched their fellow eyes as per guidelines by Pediatric Eye Disease Investigator Group. Best-corrected monocular VA and stereoacuity were measured at baseline and after three months of therapy in both groups.

RESULTS

There were significant improvements in the mean acuities in amblyopic eye (AE) in both AVT (0.32±0.11 logMAR, p <0.001) and patching groups (0.27±0.19 logMAR, p ˂ 0.001). However, there was no significant difference in mean acuity gains in AE between AVT and patching groups (p = 0.059). Mean gains in stereoacuities (log seconds of arc) were statistically significant in both AVT (0.81±0.34, p < 0.001) and patching groups (0.32±0.34, p < 0.001). The stereoacuity gain in the AVT group was significantly higher compared to patching group (p < 0.001).

CONCLUSION

Active vision therapy had a better impact than conventional patching therapy in terms of improvement of stereoacuity but not in terms of VA when used for treating children with amblyopia.

Evaluation of visual plasticity in patients with refractive amblyopia treated using a visual perceptual learning system

BACKGROUND

Amblyopia is a neurological deficit in binocular vision that affects 3% of the population and is the result of disruptions in early visual development.

OBJECTIVE

In this study, we used a visual perceptual learning system for the short-term treatment of children with ametropic amblyopia and evaluated the clinical efficacy of this system in terms of visual plasticity.

METHODS

We conducted a retrospective analysis of the clinical data of 114 children (228 eyes) with refractive amblyopia, who were aged 6.51 ± 1.51 years. Prior to the treatment, we evaluated all children with amblyopia using the visual information processing test. We determined the type of amblyopic defect according to the type of amblyopia, corrected visual acuity, and advanced visual function test results. Based on the type of defect, each child with amblyopia was given short-term visual perception training for 10 days. Finally, we compared the results of visual acuity and visual information processing tests before and after the treatment.

RESULTS

The best-corrected visual acuity of patients was better after 10 days of visual training than that before training (P< 0.05). The perceptual eye position after training improved with statistically significant differences in horizontal and vertical perceptual eye position (both P< 0.05) compared to that before training. The number of amblyopic children without suppression in both eyes was 81 cases (71.1%) after training which was higher than that (65 cases, or 57.0%) before training, with a statistically significant difference (P< 0.05). Binocular fine stereopsis and dynamic stereopsis improved after training with a statistically significant difference (both P< 0.05).

CONCLUSION

In this study, it was found that patients with amblyopia showed visual plasticity. Moreover, continuous visual perceptual learning improved the best-corrected visual acuity and recovered stereopsis in children with refractive amblyopia.

Anisometropia and Amblyopia Outcomes in Early Versus Late Resolution of Congenital Nasolacrimal Duct Obstruction in Older Infants

PURPOSE

Congenital nasolacrimal duct obstruction is a known risk factor for amblyopia and anisometropia. The purpose of this study was to investigate whether the rate of anisometropia and amblyopia development differed based on the age at CNLDO resolution in older infants.

METHODS

This retrospective chart review at a single tertiary children's hospital from 2007 to 2017 compared early versus late spontaneous resolution (cutoff 12 months) and intervention (cutoff 15 months) groups presenting at ≥9 months of age, comparing visual outcomes, including anisometropia (≥1 D of sphere or cylinder) and amblyopia (≥2 levels difference in Teller acuity or optotype testing). Parents/guardians were contacted by phone for missing data on spontaneous resolution or intervention status.

RESULTS

A total of 462 patients were included (152 early; 310 late group). The early group presented at a median age of 12.0 (interquartile range: 10.0, 13.0) months, while the late group presented at 21.0 (interquartile range: 15.0, 32.0) months. Unilateral disease occurred in 62% and 59%, respectively. Anisometropia was seen in (12/102) 12% of early versus (25/243) 10% of late patients (p = 0.686, 95% CI: -0.059, 0.088), and amblyopia in (4/131) 3% of early versus (14/286) 5% of late patients (p = 0.322, 95% CI: -0.061, 0.018). In patients presenting <24 months without undergoing surgery, spontaneous resolution occurred in 76% between 12 and 24 months (n = 41).

CONCLUSIONS

Anisometropia and amblyopia rates did not significantly differ between early and delayed intervention for congenital nasolacrimal duct obstruction in this retrospective cohort presenting beyond 9 months of age to a children's hospital. This study found frequent late spontaneous resolution.

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.].

Treatment of Anisometropic Amblyopia with a Dichoptic Digital Platform in Argentinian Children and Adults

PURPOSE

To evaluate and compare the results of dichoptic training in Argentinian children and adults with anisometropic amblyopia.

METHODS

Prospective non-comparative study enrolling 41 subjects with anisometropic amblyopia (age, 6-60 years old). Two groups were differentiated according to age, children (6-16 years, 24 subjects) and adults (>17 years, 17 subjects). All patients were treated with the Bynocs® platform (Kanohi Eye Pvt. Ltd, India) following a protocol of 30 sessions of training of 30 min daily 5 times a week for 6 weeks. Changes in corrected distance visual acuity (CDVA) and binocular function (BF) score with treatment were analyzed.

RESULTS

In the whole sample, CDVA in the amblyopic eye improved significantly, with a mean change of 0.30 logMAR (p < .001). Likewise, a significant improvement was also found in BF score (p < .001), with a mean change of 1.14 log units. The change achieved in CDVA was significantly correlated with the baseline CDVA in the amblyopic eye (r=-0.568, p < .001). Furthermore, no significant differences were found between age groups in the change achieved in CDVA (p = .431) and BF with therapy (p = .760).

CONCLUSIONS

Dichoptic training with the digital platform evaluated provides an effective improvement of visual acuity and binocular function in children and adults with anisometropic amblyopia.

Current Developments in the Management of Amblyopia with the Use of Perceptual Learning Techniques

Background and Objectives: Amblyopia is a neurodevelopmental disorder caused by interocular suppression of visual input, affecting visual acuity, stereopsis, contrast sensitivity, and other visual functions. Conventional treatment comprises occlusion of the sound eye. In recent years, novel therapies that deploy perceptual learning (PL) principles have been introduced. The purpose of this study is to assess the latest scientific data on this topic. Materials and Methods: For this purpose, we conducted a literature search for relevant studies published during the previous 4 years (2020-2023). Results: A plethora of visual perceptual learning protocols have been recently developed. Dichoptic video games, contrast rebalanced movies, and online perceptual training platforms are the main formats. Perceptual learning activates neuroplasticity, overcomes interocular suppression, and improves the visual impairments induced by amblyopia. Conclusions: This novel treatment is effective in both children and adults, as well as in patients non-responding to patching.

Treating amblyopia using altered reality enhances the fine-scale functional correlations in early visual areas

Amblyopia is a developmental visual disorder that causes substantial visual deficits. Studies using resting-state functional magnetic resonance imaging have disclosed abnormal brain functional connectivity (FC) both across long-range cortical sites and within the visual cortex in amblyopes, which is considered to be related to impaired visual functions. However, little work has examined whether restoring the vision of amblyopes accompanies with an improvement of FC. Here in adult amblyopes and healthy participants, we compared their brain FC before and after an altered-reality adaptation training. Before the training, the voxel-wise FCs of amblyopia patients were substantially weaker than those of healthy control participants both within and across the early visual areas. After the training, visual acuities improved in amblyopes but not in the control participants. The effect kept strengthening in the subsequent month without further adaptation. Importantly, we observed enhanced voxel-wise FC both within and across the early visual areas of amblyopes. Moreover, the enhancement continued for at least 1 month. These results suggest that the effective treatment can improve both the amblyopes' vision and functional connections in the visual cortex.

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.

Invited Session V: Binocular vision and interactions: Harnessing interactions within binocular vision to treat amblyopia

Inexpensive virtual reality (VR) headsets have enabled at-home therapy for binocular dysfunctions, including amblyopia. Healthy binocular vision is exquisite, which is achieved though interactions among various visual subsystems. As a result, however, binocular vision has multiple points of weakness, so development can go wrong in many different ways. Furthermore, the visual system has many ways it can adapt to dysfunctions to improve vision. It is therefore not surprising that amblyopias are idiosyncratic from one person to the next. Habitual interocular suppression is a typical adaption in amblyopia, and by treating suppression in VR, acuity can be improved by 0.1 to 0.2 logMAR. However, the amblyopic visual system shows complicated patterns of interaction between suppression, acuity, stereopsis, motor vergence, accommodation, and motion perception; and each of those subsystems is itself complex. Thus, to improve acuity and stereopsis in amblyopia, a multifaceted approach would seem more promising. In a VR headset, one can addresses suppression, stereopsis, vergence ability, and even accommodation, simultaneously. I will describe Vivid Vision's approach to this problem, along with preliminary results from independent researchers.

Long-term outcomes of type 1 retinopathy of prematurity following monotherapy with bevacizumab: a Canadian experience

OBJECTIVE

To report long-term structural, visual, and refractive outcomes after monotherapy with intravitreal bevacizumab injection.

DESIGN

Cohort retrospective chart review.

PARTICIPANTS

A total of 56 premature infants with type 1 retinopathy of prematurity.

METHODS

This is a chart review at 2 Canadian institutions. Inclusion criteria were single injection of 0.625 mg  intravitreal bevacizumab and minimum age at last follow-up of 3 years. Primary outcome was retinal structure. Secondary outcomes were refractive error in spherical equivalent, monocular visual acuity, strabismus, and amblyopia.

RESULTS

Fifty-six infants (101 eyes) met inclusion criteria. Mean birth weight was 707 ± 178 g (range, 420-1520 g). Mean gestational age was 25.0 ± 1.3 weeks (range, 22.9-29.7 weeks). Twenty-four eyes were in zone I (24%) and 77 in zone II (76%). Mean postmenstrual age at treatment was 36.9 ± 2.1 weeks (range, 32.8-42.0 weeks). At a mean age of 5.4 ± 1.6 years (range, 3.0-8.0 years), all eyes had a favourable structural outcome with no reactivation requiring treatment. Mean monocular visual acuity was 0.29 ± 0.27 logMAR (range, 0.0-1.3 logMAR; 89 of 101 eyes). Mean spherical equivalent was -1.98 ± 4.91 D (range, -16.63 to +5.38 D; 101 of 101 eyes). Prevalence of emmetropia (>-1.0 to ≤1 D) was 43.6%; low myopia (≥1.0 to <5 D) was 17.8%; high myopia (≥5 to <8 D) was 8.9 %; very high myopia (≥8.0 D) was 12.9%; and hyperopia (>1 D) was 16.8%. Twelve children (23%) had amblyopia, and 17 (32%) developed strabismus.

CONCLUSIONS

All patients demonstrated a favourable structural outcome with a single bevacizumab injection without the need for additional laser. We suggest regular monitoring following regression of acute retinopathy of prematurity as an alternative to universal, preplanned delayed prophylactic laser treatment. Future studies to evaluate other aspects of visual function are needed.

Is there value in measuring near visual acuity during occlusion therapy for amblyopia?

Introduction: The purpose of this study was to investigate near and distance visual acuity (VA) prior to, during and on completion of occlusion therapy for amblyopia. Method: Fifty-four patients aged 4-7 years (mean 4.9; ±0.44) with untreated strabismic, anisometropic or mixed amblyopia were recruited to the study following refractive adaptation where applicable. All patients underwent conventional occlusion (patching). Uniocular near and distance VA was tested using age and ability appropriate Crowded LogMAR VA tests prior to, during and upon conclusion of occlusion therapy. Results: In amblyopic eyes, there was no significant difference between near and distance VA prior to occlusion therapy with LogMAR Crowded (p = .66; mean distance VA at 3 m = 0.6 LogMAR; mean near VA at 40 cm = 0.58 LogMAR), or with LogMAR Crowded Kay Picture test (p = .78, mean distance VA at 3 m = 0.44 LogMAR; mean near VA at 33 cm = 0.46 LogMAR;). No significant difference was found between near and distance VA at any visit during occlusion therapy, or on completion of occlusion therapy with LogMAR Crowded (p = .86, mean final distance VA at 3 m = 0.266 LogMAR; mean final near VA at 40 cm = 0.25 LogMAR) or LogMAR Crowded Kay Pictures (p = .74, mean final distance VA at 3 m = 0.16 LogMAR; mean final near VA at 33 cm = 0.16 LogMAR). There was no significant difference in the VA of the fellow (non-amblyopic) eyes prior to and on completion of occlusion therapy with LogMAR Crowded at distance (3 m) or near (40 cm) (p = .05, p = .40 respectively); or with LogMAR Crowded Kay Pictures at distance (3 m) or near (33 cm) (p = .89, p = .35 respectively). Discussion: Improvement in VA of amblyopic eyes did not significantly differ between near and distance testing proximites at any point during the course of occlusion therapy for amblyopia in our study. These findings may aid clinicians with appropriate test selection and help with clinical time pressures. Where patient concentration does not allow for uniocular distance vision, uniocular near vision may be used to diagnose amblyopia, and vice versa. This could prevent delay in the treatment of amblyopia.

Factors affecting the total occlusion time in eyes with hyperopic anisometropic amblyopia

BACKGROUND

Amblyopia treatment by occluding the healthy eye is known to be effective during a sensitive critical period. This study aims to clarify the factors for the total occlusion time (TOT) required for the amblyopic eye to achieve a normal visual acuity (VA) level of 1.0 (0.0 logMAR equivalent). This could contribute to an efficient treatment plan for eyes with hyperopic anisometropic amblyopia.

METHODS

Subjects were 58 patients (26 boys and 32 girls; age range, 3.6-9.2, average, 5.8 ± 1.3 years) with hyperopic anisometropic amblyopia. All the subjects had initially visited and completed occlusion therapy with improved VA of 1.0 or better in the amblyopic eye at Kindai University Hospital between January 2007 and March 2017. Using the subjects' medical records, we retrospectively investigated five factors for the TOT: the age at treatment, the initial VA of the amblyopic eye, refraction of the amblyopic eye, anisometropic disparity, and the presence of microstrabismus. Patient's VA improvement at one month after treatment was also evaluated to confirm the effect of the occlusion therapy.

RESULTS

The initial VA of the amblyopic eye ranged from 0.1 to 0.9 (median, 0.4). The TOT ranged from 140 to 1795 (median, 598) hours with an average daily occlusion time of 7 hours. The initial VA of the amblyopic eye and presence of microstrabismus were the significant factors for the TOT (p < 0.01). To achieve VA of 1.0 or better, patients with an initial VA of ≤ 0.3 in the amblyopic eye required a longer TOT. Moreover, patients with concomitant microstrabismus required a 1.7-fold longer TOT compared to those without microstrabismus.

CONCLUSION

Longer daily occlusion hours and early start of the treatment will be necessary for patients with poor initial VA or microstrabismus to complete occlusion therapy within the sensitive critical period.

Computer-Assisted Visual Training in Children and Adolescents with Developmental Visual Disorders

BACKGROUND

In this systematic review, we address the question whether children and adolescents with developmental visual disorders benefit from computer-assisted visual training.

METHODS

Systematic literature searches were carried out in three bibliographic databases (initial search in October 2021) and trial registries. Included were randomized controlled trials that evaluated the efficacy of computer-assisted visual training in children and adolescents with developmental visual disorders in comparison to no training, sham training, or conservative treatment.

RESULTS

The inclusion criteria were met by 17 trials (with a total of 1323 children and adolescents) focusing on binocular or monocular computer-assisted visual training for the treatment of amblyopia. In these trials, visual training was carried out for 2 to 24 weeks, either as "stand alone" therapy or in addition to occlusion therapy. Six trials showed a statistically significant difference in favor of the visual training for the outcome "best corrected visual acuity of the amblyopic eye." However, this difference was small and mostly below the threshold of clinical relevance of -0.05 logMAR (equivalent to an improvement of 0.5 lines on the eye chart, or 2.5 letters per line). Only few data were available for the outcomes "binocular vision" and "adverse events"; the differences between the groups were similarly small.

CONCLUSION

The currently available data do not permit any firm conclusions regarding the efficacy of visual training in children and adolescents with amblyopia. Moreover, treatment adherence was often insufficient and the treatment durations in the trials was relatively short. No results from randomized trials have yet been published with respect to other developmental visual disorders (refractive errors, strabismus).

Prevalence of residual amblyopia in adulthood and its association on educational outcome and quality of life in the Northern Finland Birth Cohort

PURPOSE

The purpose of the current study was to evaluate the prevalence of residual amblyopia in adults in a population screened and treated in childhood. We also wanted to evaluate the association of amblyopia on school success, level of education, and quality of life.

METHODS

This is a follow-up study of 2708 subjects of the Northern Finland Birth Cohort. At the age of 46, the subjects took part in ophthalmic examinations, including the measurement of best-corrected visual acuity (BCVA) and refraction. Residual amblyopia was defined as BCVA 20/30 or less (logMAR ≥0.2) in one or both eyes or a two-line interocular visual acuity difference and absence of any pathological ocular factors. The quality of life was assessed with a 15D questionnaire, and educational outcome, school success, and episodic memory with a CANTAB-PAL (paired associates learning) test were evaluated.

RESULTS

The prevalence of amblyopia in the current adult population aged 46 years was 1.3% (n = 36). At 14 years, the amblyopia subjects had had significant differences in mean spherical equivalent between the amblyopic and fellow eye and strabismus more often than controls. No significant differences were observed in the CANTAB-PAL test or in educational outcome. However, amblyopia subjects had significant difficulties in the 15D questionnaire in terms of vision (54% vs. 34%, p = 0.01).

CONCLUSION

Due to screening and treatment in childhood, the number of adults with residual amblyopia was low. Despite minor visual impairment and discomfort, they cope very well in life in terms of educational outcome and quality of life.

A Prospective Trial to Assess the Efficacy of Eye-Tracking-Based Binocular Treatment versus Patching for Children's Amblyopia: A Pilot Study

PURPOSE

To assess visual acuity (VA) and stereoacuity (SA) improvements in children with amblyopia treated with either binocular dichoptic treatment or patching treatment.

METHODS

In this pilot prospective coherent study, 34 participants between 4 and 9 years of age with unilateral anisometropic amblyopia and without history of prior amblyopia treatment were enrolled into three groups. Full treatment group (FTG; n = 12): participants were prescribed the binocular dichoptic treatment to watch for 90 minutes per day, 5 days a week. Part-time treatment group (PTTG; n = 8): participants were prescribed the same binocular treatment as FTG, 90 minutes per day, 3 days per week. Patching treatment group (PTG; n = 14): participants wore an adhesive patch over the dominant eye for 2 hours per day, 7 days per week. Amblyopic-eye distance visual acuity (DVA), near visual acuity (NVA) and SA were evaluated at baseline, 4, 8, and 12 weeks.

RESULTS

At 12 weeks, mean amblyopic-eye DVA improved 1.8 lines (95% CI, 1.1-2.5) in FTG, 1.5 lines (95% CI, 0.4-2.7) in PTTG and 3.0 lines (95% CI, 2.0-4.0) in PTG. The amblyopic-eye NVA improved 2.9 lines (95% CI, 2.4-3.5) in FTG, 1.7 lines (95% CI, 0.5-3.0) in PTTG and 2.8 lines (95% CI, 1.8-3.9) in PTG. The SA improved 0.38 log-arcseconds (95% CI, 0.24-0.53) in FTG, 0.59 log-arcseconds (95% CI, 0.36-0.82) in PTTG and 0.40 log-arcseconds (95% CI, 0.13-0.67) in PTG. No significant differences were found in DVA, NVA or SA improvement between FTG and PTG at 12 weeks.

CONCLUSIONS

VA and SA after binocular dichoptic treatment produced a similar therapeutic outcome to patching, suggesting a potential value for binocular therapy when treating anisometropic moderate degree of Children's amblyopia.

Pediatric Cataract: Disparately Blinding Globally and in the United States

Childhood cataract is a complex condition requiring longitudinal care, including early diagnosis, timely referral to a specialist, early surgical intervention, and dedicated postoperative care. Adherence to refractive correction and amblyopia therapy are critical for visual rehabilitation, even months to years after the cataract is removed. We review the impact of the social determinants of health on each step in the visual rehabilitation pathway for children with congenital and infantile cataracts. Children from socioeconomically marginalized backgrounds are more likely to experience delays in access to care and utilization of surgical services. They are also less likely to adhere to amblyopia therapy, with corresponding decrements in visual outcomes. Additional sociocultural factors, including parental stress, self-efficacy, and health literacy, pose barriers for these children. Standardizing clinical roles, improving health communication, managing parental stress, and implementing systemic policy changes may alleviate socioeconomic disparities in outcomes for children with cataracts.

Managing Pediatric Cataract Patients: Amblyopia Treatment and Binocularity Outcomes

Unilateral congenital cataracts present multiple barriers in the development of vision and stereoacuity despite the improved visual optics that early surgery, contact lenses and intraocular lenses (IOL) have provided. With better understanding of the latent period (the timeframe in which the abnormal event has no long-term effect on visual development in the deprived eye) and the critical periods (the age range during which developing brains can be altered in a profound and permanent way by abnormal experience) for stereoacuity and amblyopia we can focus our treatment methods to not only improve vision but also develop binocularity. Fifty years ago, it was believed that it was almost impossible for an eye with a unilateral congenital cataract to achieve good visual acuity. Twenty-five years ago, we believed that it was almost impossible for an eye with a unilateral cataract to achieve stereoacuity. It is time to expand our belief that the best that we can do with the eye in unilateral congenital cataract is to create a spare.

Amblyopia treatment outcomes in patients with neurodevelopmental disorders

PURPOSE

To compare amblyopia treatment outcomes between patients with neurodevelopmental disorders and their typically developing peers.

METHODS

Of 2,311 patients diagnosed with amblyopia between 2010 and 2014 at Boston Children's Hospital, 460 met inclusion criteria (age 2-12 with anisometropic, strabismic, or mixed amblyopia [interocular difference (IOD) ≥2 lines]). Treatment and visual outcomes were analyzed according to neurodevelopmental status: neurodevelopmental delay (DD) versus typical development (TD).

RESULTS

The DD group (n = 54) and TD group (n = 406) were similar in demographics, amblyogenic risk factors, baseline visual measures, prescribed therapy, and adherence (P ≥ 0.10). Between-visit follow-up time was longer for the DD group (0.65 [0.42- 0.97] years) than for the TD group (0.5 [0.36-0.82] years; P = 0.023). IOD improved similarly in each group by the last visit (DD, -0.15 logMAR [-0.31 to -0.02]; TD, -0.2 logMAR [-0.38 to -0.1]; P = 0.09). Each group reached amblyopia resolution by the last visit at similar frequencies (DD, 23/54 [43%]; TD, 211/406 [52%]; P > 0.2). DD diagnosis did not independently influence amblyopia resolution (HR, 0.77; 95% CI, 0.53-1.12; P = 0.17), but each additional month of interval time between follow-up visits reduced the likelihood of resolution by 2.7% (HR, 0.67; 95% CI, 0.51-0.87; P = 0.003).

CONCLUSIONS

Patients with DD and those with TD responded similarly to amblyopia therapy; however, follow-up intervals were longer in patients with DD and correlated with the likelihood of persistent amblyopia, suggesting that greater efforts at assuring follow-up may benefit patients with DD.

Straatsma Syndrome and cataract: case report and review of the literature

Straatsma Syndrome is known as unilateral myopia, amblyopia, and myelinated retinal nerve fibers (MRNF). The syndrome can be associated with other findings such as nystagmus, strabismus, and optic nerve hypoplasia among others. However, no cases associated with cataract have been reported. The visual prognosis depends on the myelinated retinal nerve fibers extension, the early amblyopia therapy, and the coexistence of other signs. We present the case of a 4-year-old girl with Straatsma Syndrome and cataract in the left eye. Despite the cataract surgical treatment with the refractive error correction and the amblyopia therapy, no visual improvement has been reported. Abbreviations: MRNF = Myelinated retinal nerve fibers, LE = Left eye, PD = Prism dioptres, BCVA = Best-corrected visual acuity, RE = Right eye, HM = Hand movement, CF = Counting fingers.

Risk of recurrence after cessation of dichoptic, binocular treatment of amblyopia

Contrast-rebalanced dichoptic games and videos have been shown to be an effective treatment for childhood amblyopia. Whether the visual acuity gains achieved with these binocular treatments are long-lasting has not been determined. In this prospective cohort study of 100 consecutive amblyopic children who improved by ≥0.2 logMAR or obtained ≤0.2 logMAR amblyopic eye visual acuity during a binocular treatment clinical trial, risk of recurrence was 24% (95% CI, 16%-35%) at up to 3 years' follow-up according to Kaplan-Meier survival analysis, which accounts for censored, truncated, and missing data. Risk of recurrence was similar among children who required additional treatment for residual amblyopia after 4-8 weeks of dichoptic treatment (n = 62 [19%]; 95% CI, 10%-34%) and those who did not (n = 38 [32%]; 95% CI, 18%-52%; P = 0.12). There was no association between recurrence and age, visual acuity at the end of binocular treatment, stereoacuity, or ocular alignment. In a secondary analysis to compare rates of recurrence with published data, risk of recurrence in the subset of children who had no additional treatment for residual amblyopia (28%) was similar to the reported recurrence after cessation of successful patching and atropine (24%) at 12 months. Children with successful binocular treatment of amblyopia require monitoring for recurrence of amblyopia.

Factors associated with visual acuity improvement with a binocular digital therapeutic for amblyopia

We combined data from 121 amblyopic children enrolled in two prospective open-label pilot studies and a randomized trial of a binocular digital therapeutic to identify factors associated with positive response to amblyopia treatment. Visual acuity improved ≥1 line in 81% of participants after 12 weeks of therapy. Treatment response was not found to be associated with age, severity of amblyopia, or prior treatment status. Although these findings may suggest broad efficacy for this treatment approach, further investigation in larger cohorts is needed to identify factors associated with treatment response.

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.

Assessment of macular microvascular changes in children following treatment of anisometropic myopic amblyopia using optical coherence tomography angiography

PURPOSE

To evaluate macular microvascular changes in the form of foveal avascular zone (FAZ) area and vessel density in the superficial, deep capillary plexuses, and choriocapillaris using optical coherence tomography angiography (OCTA) in children with anisometropic myopic amblyopia before and after treatment.

METHODS

This prospective observational study included 32 patients younger than 12 years old with anisomyopic amblyopia. OCTA was done before patients' treatment with optical correction with or without patching and was repeated after successful amblyopia treatment. Outcomes included superficial, deep, and choriocapillaris vessel density (VD) and superficial and deep FAZ areas.

RESULTS

The study included 13 males (40.6%) and 19 females (59.4%), and the mean age was 9.52 ± 1.33 years. Fifty-three percent (53%) of patients needed only optical correction, and the remaining 47% needed additional patching therapy. After successful treatment, there was a significant improvement in amblyopic eyes in best-corrected visual acuity (p < 0.001), with higher VD values in superficial capillary plexuses (p < 0.001), deep capillary plexuses (p < 0.001), and foveal choriocapillaris (p = 0.030). In the glasses with patching subgroup, the difference between pre-treatment and post-treatment parameters revealed a significant improvement in vessel density in superficial retinal plexuses (foveal and parafoveal; p values 0.023 and < 0.001, respectively) and deep retinal plexuses (whole image, foveal, and parafoveal; p values 0.003, < 0.001, and 0.002, respectively). While amblyopic eyes treated with glasses alone had a significantly greater difference in choriocapillaris foveal VD (p value = 0.022).

CONCLUSION

After effective amblyopia treatment, amblyopic eyes exhibited improved best-corrected visual acuity and better macular perfusion along the superficial, deep vascular density, and choriocapillaris foveal VD.

CLINICAL TRIAL REGISTRATION

CinicalTrials.gov Identifier: NCT05223153.

Evaluation of retinal microcirculation alterations using OCTA in hyperopic ametropic amblyopia patients before and after treatment

PURPOSE

We aimed to compare retinal microcirculation in hyperopic ametropic amblyopia patients before and after treatment and in healthy children using optical coherence tomography angiography (OCTA), and to explore the pathogenesis of hyperopic ametropic amblyopia.

METHODS

Eighteen patients with hyperopic ametropic amblyopia aged 4-8 years were selected as the patient group, and 18 age-matched healthy children were randomly selected as controls. The foveal avascular zone (FAZ) area, perimeter and circularity, vessel density (VD) and perfusion density (PD) of macular superficial retinal capillary plexus, macular thickness, peripapillary retinal nerve fiber layer thickness, and ganglion cell-inner plexiform layer thickness were compared between both groups. After 6 months of amblyopia treatment, the same parameters were measured again.

RESULTS

The VD and PD in the central, inner, inner nasal, and inner inferior regions in hyperopic ametropic amblyopia were lower than in the control group after adjustment for axial length. After 6 months of treatment, the VD increased significantly, except in the outer nasal and outer inferior regions. The PD in the central (p < 0.001), inner superior (p = 0.001), inner inferior (p = 0.011) and inner temporal (p = 0.026) regions increased. The FAZ perimeter and circularity significantly differed between the groups. After 6 months of treatment, the FAZ area and perimeter decreased, but circularity increased.

CONCLUSION

Hyperopic ametropic amblyopia eyes showed a significant decrease in vessel and perfusion densities. After amblyopia treatment, the vessel and perfusion densities of patients with hyperopic ametropic amblyopia increased, suggesting that abnormalities in the microvascular system are a pathogenic factor of amblyopia.

Effects of virtual reality on the treatment of amblyopia in children: A systematic review and meta-analysis

PROBLEM

Virtual reality technology has been used to treat amblyopia in children. However, it is unclear how virtual reality technology differs from conventional patching therapy in terms of effectiveness.

ELIGIBILITY CRITERIA

Eligible randomized controlled studies were retrieved from PubMed, Embase, Scopus, the Cochrane Library, and Web of Science through February 2023.

SAMPLE

Eight studies included 10 trials with 459 participants were included in the current meta-analysis. Two studies (Herbison et al., 2016; Huang et al., 2022) included two trials each. Thus, a total of ten trials were included in the current meta-analysis.

RESULTS

Overall, virtual reality technology treatment significantly improved visual acuity by 0.07 log MAR (95% confidence interval [CI], -0.11 to -0.02; P < 0.001; I2 = 94.4%) compared with traditional patching therapy. In addition, subgroup analyses also revealed that treatment with virtual reality technology was more effective when the child was younger than seven years old, or when the duration of the intervention was no more than twenty hours.

CONCLUSIONS

Virtual reality technology treatment showed significant effects in improving visual acuity in children who were seven years of age or younger with amblyopia.

IMPLICATIONS

Virtual reality technology treatment is effective in treating amblyopia in children. Virtual reality therapy is also entertaining and popular among children and can be applied to the treatment of amblyopia in children in the future.

Comparison of Retinal and Choroidal Microvasculature Changes in Monocular Amblyopic and Non-amblyopic Eyes following Short-term Patch Occlusion Treatment

PURPOSE

Our objective was to investigate whether there were differences in the short-term changes of retinal and choroidal microvasculature between amblyopic and non-amblyopic eyes after patch occlusion treatment in patients with monocular amblyopia. Additionally, we aimed to determine if these changes were associated with improvements in clinical parameters.

METHODS

We conducted a retrospective, longitudinal paired-eye case-control study by analyzing the medical records of patients under the age of 12 who had monocular amblyopia and underwent patch occlusion treatment for a duration of 2 to 12 months. Using optical coherence tomography angiography images, we compared the foveal avascular zone width, retinal blood vessel density (VD), choroidal thickness (CT), and choroidal vascularity index (CVI) in amblyopic and non-amblyopic eyes before and after patch occlusion treatment. We analyzed the correlations between the aforementioned parameters and changes in best-corrected visual acuity (BCVA) and stereopsis.

RESULTS

Overall, 114 eyes from 57 patients were enrolled. At baseline, parafoveal superficial plexus VD, foveal and parafoveal deep capillary plexus VD (DCPD) were lower by 0.994 ± 3.312% (p = .026), 2.403 ± 8.273% (p = .033), and 2.469 ± 4.095% (p < .001), respectively; CT was thicker by 30.6 ± 90.7 μm (p = .014); and CVI was higher by 1.920 ± 3.432% (p < 001) in the amblyopic eyes than in the non-amblyopic eyes. Following short-term patch occlusion treatment, foveal and parafoveal DCPD increased by 1.264 ± 3.829% (p = .017) and 1.028 ± 3.662% (p = .036), respectively, CT thinned by 15.5 ± 51.5 μm (p = .019), and CVI decreased by 1.296 ± 3.997% (p = .018) in the amblyopic eyes. Following patch occlusion treatment, as the foveal DCPD decreased and CVI increased, the BCVA improved (p = .017 and .035, respectively).

CONCLUSION

Following patch occlusion treatment, increased foveal DCPD and decreased CVI were associated with improved BCVA.

A population-level post-screening treatment cost framework to help inform vision screening choices for children under the age of seven

PURPOSE/BACKGROUND

Visual acuity (VA) screening in children primarily detects low VA and amblyopia between 3 and 6 years of age. Photoscreening is a low-cost, lower-expertise alternative which can be carried out on younger children and looks instead for refractive amblyopia risk factors so that early glasses may prevent or mitigate the conditions. The long-term benefits and costs of providing many children with glasses in an attempt to avoid development of amblyopia for some of them needs clarification. This paper presents a framework for modeling potential post-referral costs of different screening models once referred children reach specialist services.

METHODS

The EUSCREEN Screening Cost-Effectiveness Model was used together with published literature to estimate referral rates and case mix of referrals from different screening modalities (photoscreening and VA screening at 2, 3-4 years and 4-5 years). UK 2019-20 published National Health Service (NHS) costings were used across all scenarios to model the comparative post-referral costs to the point of discharge from specialist services. Potential costs were compared between a) orthoptist, b) state funded ophthalmologist and c) private ophthalmologist care.

RESULTS

Earlier VA screening and photoscreening yield higher numbers of referrals because of lower sensitivity and specificity for disease, and a different case mix, compared to later VA screening. Photoscreening referrals are a mixture of reduced VA caused by amblyopia and refractive error, and children with amblyopia risk factors, most of which are treated with glasses. Costs relate mainly to the secondary care providers and the number of visits per child. Treatment by an ophthalmologist of a referral at 2 years of age can be more than x10 more expensive than an orthoptist service receiving referrals at 5 years, but outcomes can still be good from referrals aged 5.

CONCLUSIONS

All children should be screened for amblyopia and low vision before the age of 6. Very early detection of amblyopia refractive risk factors may prevent or mitigate amblyopia for some affected children, but population-level outcomes from a single high-quality VA screening at 4-5 years can also be very good. Total patient-journey costs incurred by earlier detection and treatment are much higher than if screening is carried out later because younger children need more professional input before discharge, so early screening is less cost-effective in the long term. Population coverage, local healthcare models, local case-mix, public health awareness, training, data monitoring and audit are critical factors to consider when planning, evaluating, or changing any screening programme.

Relationship Between Suppression Scotomas and Stereoacuity in Anisometropic Amblyopia With Successfully Treated Visual Acuity

Purpose

The purpose of this study was to investigate the relationship among suppression scotoma size, stereoacuity, and four-prism base-out test (4ΔBOT) results in anisometropic amblyopia with successfully treated visual acuity.

Methods

We included 103 cases of anisometropic amblyopia successfully treated for visual acuity without strabismus. Stereoacuity was measured using a Randot Stereotest. The size of the suppression scotomas was measured using a new device, the polarized four dot (P4D) test. This is a modification of the Worth 4 dot test (W4D) device. The patients were divided into three groups based on the 4ΔBOT results: normal (group A = 29 cases), subnormal (group B = 48 cases), and abnormal (group C = 26 cases) response groups. The horizontal diameter of the suppression scotomas and stereoacuity in logarithmic values with a base of 20 seconds of arc (″) were compared among the 3 groups.

Results

The mean age at P4D testing was 8.4 ± 2.1 years. The average horizontal diameters of the suppression scotomas were 0.35 ± 0.79Δ, 2.01 ± 0.82Δ, and 5.50 ± 2.72Δ in groups A, B, and C, respectively, showing significant differences (A versus B: P < 0.0001, A versus C: P < 0.0001, and B versus C: P < 0.0001; 1-way ANOVA). The average logarithmic stereoacuity were 1.07 (24.95″), 1.22 (38.84″), and 1.47 (82.79″) in groups A, B, and C, respectively, thereby showing significant differences between the groups (A versus B: P < 0.0001, A versus C: P < 0.0001, and B versus C: P < 0.0001; 1-way ANOVA). Stereoacuity and horizontal diameter of the suppression scotoma were strongly correlated (r = 0.732, P < 0.0001).

Conclusions

The suppression scotoma size measured using P4D correlated significantly with stereoacuity and the 4ΔBOT results.

A pilot non-randomized trial of smartphone-based anaglyph system for treatment of adult amblyopia through VR (Virtual Reality)

Purpose

To evaluate the effectiveness of amblyopia treatment through a smartphone-based anaglyph system by virtual reality (VR) in adult patients.

Methods

A total of 10 subjects diagnosed with anisometropic amblyopia were enrolled during the study period. Best Corrected Visual Acuity (BCVA), stereoacuity, and contrast acuity were evaluated during three visits (at presentation, 3 months and 6 months) of smartphone-based anaglyph video run in the VR mode. All the amblyogenic factors including stereopsis, color vision, and contrast acuity were compared using Friedman two-way analysis of variance. Statistical significance was considered if P < 0.05.

Results

Mean BCVA in amblyopic eye improved significantly from a logMAR value of 0.73 ± 0.64 before Virtual reality vision therapy (VRVT) to a post-training VRVT value of 0.48 ± 0.44 (P < 0.01). Mean stereoacuity changed from a value of 560.00 ± 301.58 before VRVT to a value of 263.00 ± 143.58 seconds of arc after training (VRVT) (P < 0.01). Mean accommodation changes from a value of 15.00 ± 7.40 before training or VRVT to value of 12.60 ± 6.10 cm after training (P < 0.01). Mean contrast acuity changes from a value of 1.21 ± 0.72 at presentation to a value of 1.52 ± 0.49 log unit after VRVT.

Conclusion

A smartphone-based anaglyph system using VR vision therapy appears to be an effective treatment option for amblyopia in adults.