Prevalence of Amblyopia in School-Aged Children and Variations by Age, Gender, and Ethnicity in a Multi-Country Refractive Error Study

The Performance of Spot Photoscreener in 6 to 10 Weeks Infants in China: A Cross-Sectional Study

Purpose

To compare the refractive errors measured by the Spot photoscreener (with or without cycloplegia) to cycloplegic retinoscopy in 6- to 10-week-old infants.

Materials and Methods

101 right eyes from 101 healthy infants aged 6 to 10 weeks were recruited for this cross-sectional observational study. Refractive errors were measured using Spot photoscreener before and after cycloplegia, as well as cycloplegic retinoscopy. Comparisons between the refractive measurements were performed using one-way ANOVA with the post hoc Tukey HSD test or Kruskal-Wallis test with the Steel-Dwass test according to the data normality. Pearson's correlation test and 95% confidence intervals were calculated. The agreement was evaluated using a Bland-Altman plot with 95% limits of agreement of the differences.

Results

Spot photoscreener was found to underestimate the spherical equivalent by 2.33 Diopters (D) in these infants. Following the induction of cycloplegia, the spherical equivalent measured by Spot photoscreener was in excellent agreement with cycloplegic retinoscopy with the mean difference of 0.01 D. Spot photoscreener overestimated cylindrical parameter by 0.2 D with poor agreement with cycloplegic retinoscopy no matter whether cycloplegia was induced. It had good agreement with cycloplegic retinoscopy in the J0 vector than the J45 vector measurement.

Conclusions

With the induction of cycloplegia, Spot photoscreener can accurately evaluate spherical equivalent in hyperopic infants with mild-to-moderate astigmatism. While it may provide valuable measurements of astigmatism, discrepancies in cylinder and axis should be taken into account.

Vision Loss in Children from Immigrant and Nonimmigrant Households: Evidence from the National Survey of Children's Health 2018-2020

The aim of this study was to determine whether immigrant generation is associated with caregiver-reported vision loss in children adjusting for sociodemographic characteristics. Nationally representative data from the National Survey of Children's Health (2018-2020) was used. The primary exposure was immigrant generation defined as: first (child and all reported parents were born outside the United States); second (child was born in the United States and at least one parent was born outside the United States); third or higher (all parents in the household were born in the United States). The main outcome was caregiver-reported vision loss in child. Adjusted odds ratios (aOR) and 95% confidence intervals were computed based on immigration generation. The study sample included 84,860 US children aged 3-17 years. First generation children had higher adjusted odds of caregiver-reported vision loss (aOR 2.30; 95% CI 1.21, 4.35) than third or higher generation children after adjusting for demographic characteristics and social determinants of health. For Hispanic families, first generation (aOR 2.99; 95% CI 1.34, 6.66), and second-generation children (aOR 1.70; 95% CI 1.06, 2.74) had a higher adjusted odds of vision loss compared with third or higher generation children. Even when adjusting for sociodemographic characteristics, first generation children had greater odds of vision loss, especially in Hispanic households, than third generation children. Immigration generation should be treated as an independent risk factor for vision loss for children and is a social determinant of eye health.

Peripheral Binocular Imbalance in Anisometropic and Strabismic Amblyopia

Purpose

Individuals with amblyopia experience central vision deficits, including loss of visual acuity, binocular vision, and stereopsis. In this study, we examine the differences in peripheral binocular imbalance in children with anisometropic amblyopia, strabismic amblyopia, and typical binocular vision to determine if there are systematic patterns of deficits across the visual field.

Methods

This prospective cohort study recruited 12 participants with anisometropic amblyopia, 10 with strabismic amblyopia, and 10 typically sighted controls (age range, 5-18 years). Binocular imbalance was tested at 0°, 4°, and 8° eccentricities (4 angular locations each) using band-pass filtered Auckland optotypes (5 cycles per optotype) dichoptically presented with differing contrast to each eye. The interocular contrast ratio was adjusted until the participant reported each optotype with equal frequency.

Results

Participants with anisometropic and strabismic amblyopia had a more balanced contrast ratio, or decreased binocular imbalance, at 4° and 8° eccentricities as compared with central vision. Participants with strabismic amblyopia had significantly more binocular imbalance in the periphery as compared with individuals with anisometropic amblyopia or controls. A linear mixed effects model showed a main effect for strabismic amblyopia and eccentricity on binocular imbalance across the visual field.

Conclusions

There is evidence of decreased binocularity deficits, or interocular suppression, in the periphery in anisometropic and strabismic amblyopia as compared with controls. Notably, those with strabismic amblyopia exhibited more significant peripheral binocular imbalance. These variations in binocularity across the visual field among different amblyopia subtypes may necessitate tailored approaches for dichoptic treatment.

Developing a Novel Pediatric Eye Chart Assessing Visual Acuity by Minimum Separable Threshold

The purpose of this study was to develop a new pediatric acuity chart that can assess the minimum separation threshold by incorporating the minimum separation threshold into the picture. To overcome the design limitations of the Landolt ring, two designs of highly versatile minimum separable thresholds that can be easily incorporated into a picture were created: a black, filled circle (the "Circle") and a segment (the "Square"), both with the same break as in the Landolt ring. The three designs-the Landolt ring, Circle, and Square-were used to evaluate and compare the differences in the visual acuity of 21 healthy adults. No significant differences were observed between the results of the visual acuity tested with the Landolt ring, Circle, and Square (Landolt ring vs. Circle: p = 0.92, Landolt ring vs. Square: p = 0.31, Circle vs. Square: p = 0.40). The Bland-Altman analysis revealed no fixed errors between the Landolt ring and Circle and between the Landolt ring and Square (95% CI: -0.09-0.08, -0.09-0.12). Proportional errors were also not observed (p = 0.68, p = 0.41). The Landolt ring, Circle, and Square designs obtained equal results in visual acuity, thus achieving the successful development of a novel pediatric visual acuity chart using these designs.

Characteristics associated with blindness or visual impairment within the adolescent demographic: a national cohort analysis

BACKGROUND

Psychosocial metrics associated with self-reported blindness or visual impairment for adolescents in the National Survey of Drug Use and Health (NSDUH) have not been fully characterized. This retrospective cohort analysis of the latest NSDUH aimed to determine novel characteristics associated with self-reported visual loss among adolescents in the United States.

METHODS

Data from the NSDUH2020, a publicly available, federally validated database, were analyzed. Self-reported severe visual impairment or blindness was defined as being truly blind or having serious difficulty seeing even when wearing corrective lenses (s-rSVI). Inclusion criteria were all cases of s-rSVI in adolescents aged 12-17 years. NSDUH weights were used to accommodate complex survey design, nonresponse rates, and population variance. Weighted percentages, asymptotic two-sided Rao-Scott χ2 analyses, and multivariable logistic regression were performed. Statistical significance was considered reached at P < 0.05.

RESULTS

A total of 5,667 adolescents aged 12-17 years were surveyed, and s-rSVI occurred in 236 cases (weighted percentage, 3.48%). Within our final multivariable risk model, characteristics associated with increased odds of s-rSVI were female sex, Asian and Latino race/ethnicity (relative to non-Hispanic White), and self-reported serious difficulty hearing and concentrating (all P < 0.05).

CONCLUSIONS

This national retrospective cohort analysis highlights risk factors associated with s-rSVI for adolescents within the 2020 NSDUH. Clinicians and policymakers should consider at-risk demographics for s-rSVI during development and enhancement of screening programs, population health initiatives, and healthcare policy issues.

Measurement Accuracy When Using Spot Vision Screener With or Without Cycloplegia in Young Adults

Purpose

There are many unclear points about the accuracy of measurement of cycloplegic refraction using the Spot Vision Screener (SVS). This study aimed to investigate the accuracy of SVS measurements with cycloplegia for myopia.

Materials and Methods

Forty-nine healthy subjects were included, and refraction was measured. Objective refractions were measured by SVS, table-mounted autorefractometer (RT7000), and handheld autorefractometer (Retinomax Screeen) at noncycloplegic and cycloplegic conditions by 1% cyclopentolate. Subjective noncycloplegic refraction was obtained by a visual acuity and refraction test performed by certified orthoptists using a cross-cylinder. One-way repeated-measures analysis of variance was used to examine whether the measured refractions fluctuate due to different reflection tests.

Results

In the noncycloplegic condition, the mean (±standard deviation) spherical equivalent (SE) measured by subjective method, SVS, RT7000, and Retinomax Screeen were -2.56 ± 3.00, -2.62 ± 2.38, -3.05 ± 2.84, and -3.26 ± 2.97, respectively. The subjective SE and objective SE measured by SVS had significantly less myopic value than the objective SE measured by two autorefractometers (p < 0.001). In the cycloplegic condition, the mean (± standard deviation) SE measured by SVS, RT7000, and Retinomax Screeen were -2.07 ± 2.66, -2.62 ± 2.98, and -2.66 ± 3.02, respectively. The objective SE measured by SVS had significantly less myopic value than SEs measured using other methods (p < 0.001). In the cycloplegic condition, SVS showed a fixed error wherein the SE was more hyperopic than that with the subjective method and SVS had a proportional error.

Conclusion

In the measurement under cycloplegic conditions, use of an autorefractometer rather than a photorefractometer such as SVS was preferable.

Visual factors associated with physical activity in schoolchildren

CLINICAL RELEVANCE

Physical activity is an essential part of childhood physical and mental development. Recent research identified visual problems associated with a sedentary lifestyle in children in Ireland.

BACKGROUND

This study explored the association between visual function in children and their engagement with physical activities outside school.

METHODS

Participants were 1,626 schoolchildren (728 aged 6-7-years, 898 aged 12-13-years) in randomly selected schools in Ireland. Before data collection, parents/legal guardians of participants completed a standardised questionnaire reporting physical activity as no activity (mostly on screens), light activity (occasional walking/cycling), moderate activity (<3 hrs/week engaged in sports), or regular activity (>3hrs/week engaged in sports). Measurements included logMAR monocular visual acuities (with spectacles and pinhole), in the distance (3 m) and near (40 cm), stereoacuity (TNO stereo-test), cover test, and cycloplegic autorefraction (1% cyclopentolate).

RESULTS

Controlling for confounders (socioeconomic disadvantage and non-White ethnicity), linear regression analysis revealed presenting distance visual acuity, near visual acuity, and stereoacuity were significantly better amongst participants who reported regular physical activity rather than moderate, light or no activity in both 6-7-year-old and 12-13-year-old participants. Absence of clinically-significant refractive error (>-0.50D < 2.00D) was associated with regular physical activity. Participants presenting with visual impairment (better-eye vision <6/12) (odds ratio = 5.78 (2.72-12.29)), amblyopia (pinhole acuity ≤6/12 plus an amblyogenic factor) (odds ratio = 5.66 (2.33-13.76)), and participants at school without their spectacles (odds ratio = 2.20 (1.33-3.63)), were more likely to report no activity.

CONCLUSIONS

Children regularly engaged in physical activities, including sports; had better visual and stereoacuity; and were less likely to need spectacles. Visual impairment, amblyopia, and refractive error were associated with no physical activity. Spectacle wear compliance was associated with regular physical activity. Regular physical activity is an essential factor in childhood vision and addressing visual impairment in children is vital to increasing participation in sports and exercise. Socioeconomically disadvantaged and non-White communities would benefit most from these measures.

Citation Network Analysis on the Influence of Vision on Academic Performance

BACKGROUND

Proper vision is absolutely critical to children's academic performance, as vision problems can drastically affect learning ability. Currently, the existing literature in this field is somewhat inconsistent and carries several controversies about the influence of vision on academic performance. In this study, citation networks were utilized in order to analyze the relationship between publications and authors, the most-cited publication, and the different research areas. Additionally, the most commonly utilized publication sources along with the most common research areas were also pinpointed.

METHODS

The aforementioned search was executed in the Web of Science database, with a time range beginning in 1941 and ending in 2022. In order to scrutinize the publications, VOSviewer, CiteSpace software, and the Citation Network Explorer were utilized for analysis about the most-cited publication and the different research areas.

RESULTS

Overall, 1342 papers were found in all fields along with 2187 citation networks. Moreover, 2020 was the year with the most publications, including 127 publications and 4 citation networks. Bull et al., published in 2008, was the most-cited work, reaching a citation index of 975. The clustering function managed to identity four groups with the most engaging research topics from researchers: motor visual skills, visual memory, the influence of vision on the different learning styles, and abnormal development of the visual system.

CONCLUSIONS

In the end, the topic with the greatest interest was the influence of visual motor skills on academic performance. Ideally, this paper will assist fellow researchers in quickly noting which topics are of greatest interest and how research in this area has evolved.

Ocular blood flow evaluation by laser speckle flowgraphy in pediatric patients with anisometropia

Purpose

To determine the differences and reproducibility of blood flow among hyperopic anisometropic, fellow, and control eyes.

Methods

We retrospectively studied 38 eyes of 19 patients with hyperopic anisometropia (8.2 ± 3.0 years of age) and 13 eyes of eight control patients (6.8 ± 1.9 years). We measured the optic nerve head (ONH) and choroidal circulation using laser speckle flowgraphy (LSFG) and analyzed the choroidal mean blur rate (MBR-choroid), MBR-A (mean of all values in ONH), MBR-V (vessel mean), MBR-T (tissue mean), and sample size (sample), which are thought to reflect the ONH area ratio, area ratio of the blood stream (ARBS). We then assessed the coefficient of variation (COV) and intraclass correlation coefficient (ICC) and compared the differences among amblyopic, fellow, and control eyes in MBR, sample, and ARBS.

Results

The ONH, MBR-A, MBR-T, and ARBS of amblyopic eyes were significantly higher than those of fellow eyes (P < 0.01, P < 0.05, and P < 0.05, respectively), and control eyes (MBR-A and ARBS, P < 0.05, for both comparisons). The sample-T (size of tissue component) in amblyopic eyes was significantly smaller than that in fellow and control eyes (P < 0.05). Blood flow in the choroid did not differ significantly between the eyes. The COVs of the MBR, sample, and ARBS were all ≤10%. All ICCs were ≥0.7. The COVs of pulse waveform parameter fluctuation, blowout score (BOS), blowout time (BOT), and resistivity index (RI) in the ONH and choroid were ≤10%.

Conclusion

The MBR value of the LSFG in children exhibited reproducibility. Thus, this method can be used in clinical studies. The MBR values of the ONH in amblyopic eyes were significantly high. It has been suggested that measuring ONH blood flow using LSFG could detect the anisometropic amblyopic eyes.

Tecnics Eyhance Iol as a Solution for Anisometropic Amblyopia Cataract Patient: a Case Report

Background

Amblyopia affects 1-3% of the population, leading to irreversible vision loss in children and adults. Treatment options include refractive correction, occlusion therapy, and atropine penalization. Anisometropic amblyopia, caused by a difference in refractive status between the eyes, can be treated using contact lenses, glasses, ICL implantation, or cataract surgery with intraocular lens implantation. Tecnis Eyhance IOL is a superior solution, improving vision after eye surgery with a low incidence of halo, glare, or starburst.

Objective

The aim is to present the case of a patient with anisometropic amblyopia, in whom Eyhance IOL was implanted in both eyes as a solution to refractive error and initial cataract due to intolerance for contact lenses.

Case report

A 58-year-old female patient presented to our clinic complaining of blurry vision in her left eye that had persisted for a year. The patient reported intolerance to contact lenses and a history of amblyopia in her right eye. CDVA was 0.20 with -9.00/-1.50 x 25◦ in her right and 0.80 with +4.00 sphere correction in her left eye, while her CNVA was J9 with +2.50 and J1 with +2.50. Slit-lamp examination revealed early cataracts in both eyes, with otherwise normal findings. A dilated fundus examination showed vitreous liquefaction and myopic macula in the right eye but normal results in both eyes' posterior segments. The IOP was within normal limits, and the eye's axial length was measured. Considering the patient's intolerance to contact lenses, cataract surgery with intraocular lens implantation was deemed appropriate. Given the anisometropic amblyopia, the Eyhance lens was selected to optimize the patient's visual acuity. Following the procedure, the patient's visual acuity improved significantly, with her best CDVA at 0.35 in the right eye and 0.95 in the left eye. With +1.50 sphere correction, the CNVA was also enhanced, with the patient reading at J4 and J1 for her right and left eye, respectively. These improvements may have positively impacted the patient's quality of life and ability to perform daily activities.

Conclusion

Anisometropic amblyopia in 58-year-old women was treated successfully with cataract surgery and implantation of Eyhance IOL.

Visual impairment in Ethiopia: Systematic review and meta-analysis

WHO Prevention of Blindness Program launched ‘‘VISION 2020” in 1999 to reduce visual impairment and eradicate avoidable blindness by the year 2020. Ethiopia launched the “VISION 2020” initiative in 2002. This systematic review and meta-analysis aimed to present the national prevalence of visual impairment at the end of “VISION 2020”. Electronic search was conducted on the PubMed, SCOPUS, EMBASE, Web of Science, CINAHL, Google scholar databases for including articles. This systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Endnote reference manager was used for downloading, organizing, and citing articles. Methodological quality was assessed using the Joanna Briggs Institute (JBI) quality appraisal tool for prevalence studies. Statistical analysis was done using the STATA™ software version 14. In this systematic review and meta-analysis, 18 studies involving 14,953 participants were included. The pooled prevalence of visual impairment in Ethiopia after correction for publication bias by Duval and Tweedie’s trim and fill analysis was estimated to be 6.24% (95% confidence interval [CI] = [2.66, 9.82]). The pooled prevalence of visual impairment among school children and adults in Ethiopia was 6.13% (95% CI = [4.27, 7.98]) and 19.89% (95% CI = [10.85, 28.93]), respectively. The most common causes of visual impairment in decreasing order of prevalence were refractive error, cataract, trachoma, glaucoma, and corneal opacity. Amblyopia was the cause of visual impairment among school-age child. The prevalence of visual impairment in Ethiopia was still significant at the end of “VISION 2020” program. Therefore, the program of “VISION 2020” should be extended and other large-scale programs were needed to reduce the prevalence of vision impairment in Ethiopia.

Cycloplegic Autorefraction as a Substitute for Cycloplegic Retinoscopy in the Pediatric Population

PURPOSE

To evaluate whether cycloplegic autorefraction can provide similar results as cycloplegic retinoscopy, allowing more comprehensive ophthalmologists to be comfortable in managing pediatric refractive error and refractive amblyopia.

METHODS

This retrospective chart review was performed to determine the mean difference in sphere, cylinder, and axis between cycloplegic autorefraction and retinoscopy, both of which were obtained on the same eye at least 30 minutes after cycloplegia and dilation with a mixed solution of tropicamide, cyclopentolate, and phenylephrine.

RESULTS

A total of 34 eyes (18 right, 16 left) from 18 patients were included in the analysis. Mean sphere difference between cycloplegic autorefraction and retinoscopy was 0.044 ± 0.278 diopters (D) (95% CI: -1.275 to 1.363 D), mean cylinder difference was -0.081 ± 0.236 D (95% CI: -0.706 to 0.544 D), and mean axis difference was 7.059 ± 19.676 degrees (95% CI: -32.527 to 38.878 degrees). Mean differences in sphere, cylinder, and axis were not statistically significant (P = .362, .0541, and .377, respectively).

CONCLUSIONS

In this small sample population, cycloplegic autorefraction was comparable to cycloplegic retinoscopy. Recognition of amblyopia should still prompt evaluation by a pediatric ophthalmologist. Further research is necessary to confirm whether uncomplicated refractive error in children may be sufficiently detected and managed by a comprehensive ophthalmologist. [J Pediatr Ophthalmol Strabismus. 2022:59(6):422-427.].

Effectiveness of Laser Refractive Surgery to Address Anisometropic Amblyogenic Refractive Error in Children: A Report by the American Academy of Ophthalmology

PURPOSE

To review the published literature assessing the safety and effectiveness of laser refractive surgery to treat anisometropic amblyogenic refractive error in children aged ≤ 18 years.

METHODS

A literature search of the PubMed database was conducted in October 2021 with no date limitations and restricted to publications in English. The search yielded 137 articles, 69 of which were reviewed in full text. Eleven articles met the criteria for inclusion and were assigned a level of evidence rating.

RESULTS

The 11 included articles were all level III evidence and consisted of 1 case-control study and 10 case series. Six studies used laser-assisted in situ keratomileusis (LASIK), 1 used photorefractive keratectomy (PRK), 1 used refractive lenticule extraction/small incision lenticule extraction, and the rest used a combination of LASIK, PRK, laser epithelial keratomileusis (LASEK), or refractive lenticule extraction/small incision lenticule extraction. Five studies enrolled patients with anisometropic myopia, 2 studies enrolled patients with anisometropic hyperopia, and the remainder were mixed. Although all studies demonstrated an improvement in best-corrected visual acuity (BCVA), the magnitude of improvement varied widely. As study parameters varied, a successful outcome was defined as residual refractive error of 1 diopter (D) or less of the target refraction because this was the most commonly used metric. Successful outcomes ranged between 38% and 87%, with a mean follow-up ranging from 4 months to 7 years. Despite this wide range, all studies demonstrated an improvement in the magnitude of anisometropia. Regression in refractive error occurred more frequently and to a greater degree in myopic eyes and eyes with longer follow-up, and in younger patients. Although one study reported 2 free flaps, most studies reported no serious adverse events. The most common complications were corneal haze and striae.

CONCLUSIONS

Findings from included studies suggest that laser refractive surgery may address amblyogenic refractive error in children and that it appears to decrease anisometropia. However, the evidence for improvement in amblyopia is unclear and long-term safety data are lacking. Long-term data and well-designed clinical studies that use newer refractive technologies in standardized patient populations would help address the role of refractive surgery in children and its potential impact on amblyopia.

Clinical Practice and the Attitude of Ophthalmologists Regarding Amblyopia in the Population of Jordan: A Cross-Sectional Study

Aim The study was aimed at finding out the knowledge and attitude among ophthalmologists regarding amblyopia in the population of Jordan. Methodology This was an observational cross-sectional study conducted in 2021 among ophthalmologists who live and work in the local society of Jordan and were aged between 30 and 50 years. The survey was conducted using an online questionnaire administered through email and various social media platforms. The level of knowledge and awareness of amblyopia, its causes, methods of treatment, and the best age for treating amblyopia was assessed. Results Out of 200 participants, the majority were in the age group of 30-34 years (47.5%). The male:female ratio was 1:1. The average better age for examination and treatment of amblyopia was three to five years (46%). The most common cause of amblyopia was strabismic amblyopia (50%). Children's and parents' cooperation most significantly influenced the treatment's success (49%). The preferred assessment was cycloplegic refraction (56%), and the preferred patching treatment was a direct cover placed over the eye (77%). The average time to treat amblyopia was less than three years in the majority (53.5%). The most critical factor determining the success of treatment was when the treatment began (57.5%). Conclusions Our study found that although the majority of the participants were less experienced overall, they had a good knowledge of the amblyopia age group and the method of examination. Still, there was a mixed response regarding the treatment. Hence there is a need to increase awareness regarding amblyopia by Jordanian ophthalmologists, social organizations, and educational institutes.

Progression of Vision in Chinese School-Aged Children Before and After COVID-19

Objectives: To investigate the changes of vision, including the prevalence of myopia, hyperopia, poor vision, and the spherical equivalent refraction (SER), in school-aged children before and after the pandemic of Coronavirus Disease 2019 (COVID-19).

Methods: A school-based vision screening study was performed on children in 133 primary schools in Wuhan. This study was conducted in 4 consecutive years (2018–2021).

Results: A total of 468,094 children (936,188 eyes) were recruited, 255,863 (54.7%) were boys. The SER decreased in 2020 compared to other years after the age of 10. A positive myopia shift was found in younger children aged 6 (0.1 D), 7 (0.05D), and 8 (0.03 D) in 2020 compared to 2019. The progression of vision has improved slightly in 2021. Among the students included in the study, 33.7% were myopia.

Conclusion: The vision of older children decreased significantly during the COVID-19. After the pandemic, there is still a high risk for them. In the future, the focus on vision prevention and control should move forward to preschool children.

The impact of occlusion therapy and predictors on amblyopia dose-response relationship

This study aimed to calculate the dose-response relationship and predictors of visual acuity (VA) improvement following occlusion therapy at the IWK Health Center Eye Clinic and to add to amblyopia therapy dose-response relationship literature. A retrospective chart review was performed, considering patients who reached an occlusion therapy outcome at the IWK Eye Clinic between 2012 and 2019. The treatment outcome was defined as equal VA or stable VA for three consecutive clinical visits despite reported compliance. Subjective patching hours from parental reports, not prescribed hours, were used for statistical analyses. One hundred and thirty-four patients (66 females and 68 males) ages 2-11 years were included. Results showed a dose-response relationship of 224 hours/0.1logMAR increase in VA and total dose of 1344 hours for full-time occlusion and 504 hours for part-time occlusion was required to reach outcome VA. The fastest VA improvement occurred with younger age at treatment initiation, during the first 4 weeks of treatment, and in patients with strabismic and/or severe amblyopia. Classification of amblyopia, age, VA chart, initial distance VA (amblyopic eye), and treatment dose predicted the hour dose-response relationship. Dose-response relationship was faster in younger participants, in participants with strabismic and severe amblyopia, and during the first month of occlusion. Additionally, by creating a GLM model of dose-response relationship, relationship calculations can be performed. Therefore, an estimated timeline can be developed to allow allocation of clinical resources and to prepare patients for the treatment duration required and possibly increase treatment compliance.

Visual Acuity Outcomes and Loss to Follow-up in the Treatment of Amblyopia in Children From Lower Socioeconomic Backgrounds

PURPOSE

To compare visual acuity outcomes and loss to follow-up after initiation of treatment for unilateral amblyopia in children from different socioeconomic backgrounds.

METHODS

Medical records of children diagnosed as having unilateral amblyopia at an initial encounter between 2015 and 2018 were reviewed. Medicaid and private insurance were used as proxies for socioeconomic status (SES). Data points were collected at the patients' initial, follow-up, and final visits. Visual acuity improvement was the primary outcome variable in patients with at least one follow-up appointment. In a separate analysis, failure to attend a single follow-up appointment was examined for associations with SES, race, sex, and distance traveled to appointments.

RESULTS

Seventy-three patients met the inclusion criteria; of these, 28 had Medicaid and 45 had private insurance. Visual acuity improved by 2.86 lines in the Medicaid group and 2.98 lines in the private insurance group (P = .84). Number of missed appointments and distance traveled did not correlate with visual acuity improvement. In the loss to follow-up subanalysis, 40 of 141 (28.4%) patients with Medicaid and 11 of 107 (10.3%) patients with private insurance failed to attend a single follow-up visit (P = .001). No association was found between loss to follow-up and race, sex, or distance traveled.

CONCLUSIONS

Visual acuity outcomes of treatment for amblyopia did not differ between patients with Medicaid and patients with private insurance who followed up. However, patients with Medicaid were much more likely to be immediately lost to follow-up. Measures should be taken by eye care providers and pediatricians to increase follow-up in patients from low SES populations. [J Pediatr Ophthalmol Strabismus. 2022;59(2):110-117.].

Efficacy of long-term orthokeratology treatment in children with anisometropic myopia

AIM

To explore the efficacy of the orthokeratology lens for anisometropic myopia progression.

METHODS

A retrospective study was performed. Cycloplegic refraction and axial length (AL) were collected from 50 children (10.52±1.72y) who visited Peking University Third Hospital from July 2015 to August 2020. These children's one eyes (Group A) received monocular orthokeratology lenses at first, after different durations (12.20±6.94mo), their contralateral eyes (Group B) developed myopia and receive orthokeratology as well. The data in 1-year of binocular period were recorded. AL growth rate (difference of follow-up and baseline per month) were compared between two groups by paired t test. Interocular differences of AL were compared by Wilcoxon test.

RESULTS

During monocular period, the AL growth rate of the Group A (0.008±0.022 mm/mo) was significantly slower than that of the Group B (0.038±0.018 mm/mo; P<0.0001). However, during binocular period, the AL growth rate of the Group A (0.026±0.014 mm/mo) was significantly faster than that of the Group B (0.016±0.015 mm/mo; P<0.0001). The AL difference between both eyes was 0.6 (0.46) mm, then significantly decreased to 0.22 (0.39) mm when started binocular treatment (P<0.0001). However, it was significantly increased to 0.30 (0.32) mm after a year (P<0.0001), but still significantly lower than baseline (P<0.0001).

CONCLUSION

The orthokeratology lens is efficient for control the AL elongation of monocular myopia eyes and reduce anisometropia. For the condition that the contralateral eyes develop myopia and receive orthokeratology lens later, there is no efficiency observed on control interocular difference of AL during binocular treatment.

Effect of Sequential and Simultaneous Patching Regimens in Unilateral Amblyopia

PURPOSE

Many clinicians treat unilateral amblyopia with glasses alone and initiate patching when needed; others start glasses and patching simultaneously. In this study, we reviewed the outcomes of the two approaches at our institution.

DESIGN

Retrospective nonrandomized clinical trial.

METHODS

Setting: Institutional practice.

PATIENT POPULATION

All patients diagnosed with amblyopia at Boston Children's Hospital between 2010 and 2014.

INCLUSION CRITERIA

Unilateral amblyopia (visual acuity (VA) 20/40 to 20/200 with interocular difference ≥3 lines,) age 3 to 12 years, with a 6-month follow-up visit.

EXCLUSION CRITERIA

Deprivation amblyopia, prior amblyopia treatment, treatment other than patching, surgery. Patients were categorized as "simultaneous treatment" (concurrent glasses and patching therapy at their first visit) or "sequential treatment" (glasses alone at first visit, followed by patching therapy at second visit.) Observation procedures: Patient demographics, VA, and stereopsis were compared.

OUTCOME MEASURES

VA and stereopsis at the last visit on treatment.

RESULTS

We identified 98 patients who met inclusion criteria: 36 received simultaneous treatment and 62 sequential treatment. Median amblyopic eye VA improved similarly between the simultaneous (∆0.40; interquartile range [IQR], 0.56-0.30 logMAR) and sequential (∆0.40; IQR, 0.52-0.27 logMAR) groups. Patients without stereopsis at first visit had better stereopsis outcomes with sequential treatment (5.12 [IQR, 4.00-7.51] log stereopsis) compared with simultaneous treatment (8.01 [IQR, 5.65-9.21]) log stereopsis, P = 0.046).

CONCLUSIONS

VA improved approximately 4 lines regardless of treatment type. For children without stereopsis at first presentation, sequential patching yielded better stereopsis outcomes. These findings require further validation and highlight the importance of evaluating stereopsis in future studies.

The Global Prevalence of Amblyopia in Children: A Systematic Review and Meta-Analysis

Epidemiological data about the prevalence of amblyopia around the world vary widely among regions and periods. This meta-analysis aimed to determine the global prevalence of amblyopia in children. PubMed, Embase, and the Cochrane Library were searched for prevalence studies published up to 5 November 2021. The outcome was the prevalence of amblyopia, analyzed as pooled estimates with 95% confidence intervals (CI). A total of 97 studies were included, including 4,645,274 children and 7,706 patients with amblyopia. The overall worldwide pooled prevalence of amblyopia was 1.36% (95%CI: 1.27-1.46%). The prevalence of amblyopia was higher in males (1.40%, 95%CI: 1.10-1.70%) than in females (1.24%, 95%CI: 0.94-1.54%) (OR = 0.885, 95%CI: 0.795-0.985, P = 0.025). The results of the meta-regression analysis showed that there were no significant associations between the prevalence of amblyopia and geographical area, publication year, age, sample size, and whether it was carried out in a developed or developing country (all P > 0.05). Begg's test (P = 0.065) and Egger's test (P < 0.001) showed that there was a significant publication bias in the prevalence of amblyopia. In conclusion, amblyopia is a significant vision problem worldwide, and public health strategies of early screening, treatment, and management are important.

Socio-demographic disparities in amblyopia prevalence among 1.5 million adolescents

BACKGROUND

Amblyopia, when not diagnosed at appropriate age, leads to uncorrectable visual impairment with considerable social and financial implications. The aim of this study was to assess socio-demographic disparities in amblyopia prevalence among Israeli adolescents, in order to identify susceptible groups in the population.

METHODS

A nationwide, population-based, cross-sectional study of Israeli adolescents examined between 1993 and 2017. All study participants underwent visual acuity examination with socio-demographic data and previous medical history documented. Associations were analyzed using univariable and multivariable logistic regression models.

RESULTS

Among 1 334 650 Israeli-born candidates aged 17.15±0.26 years, amblyopia was diagnosed in 1.07%. The overall prevalence of amblyopia has declined from 1.59% in 1993 to 0.87% in 2017. Being in the lowest socioeconomic status and below average cognitive function scores increased the odds of amblyopia in both males [odds ratio (OR) 1.64, 95% confidence interval (CI) 1.45-1.87; OR 1.27, 95% CI 1.19-1.35, respectively] and females (OR 1.61, 95% CI 1.30-1.98; OR 1.27, 95% CI 1.18-1.36, respectively). Among males, Orthodox and ultra-Orthodox educational systems were associated with increased odds of amblyopia (OR 1.16, 95% CI 1.09-1.25; OR 1.90, 95% CI 1.73-2.09). A significantly higher prevalence of amblyopia was recorded among 219 983 immigrants (1.51%, P<0.001).

CONCLUSIONS

Although the overall prevalence of amblyopia has decreased during the observed years, we found substantial evidence of socio-demographic disparities in amblyopia prevalence among adolescents, suggesting disparities in the prevention of the disease and its treatment. Demonstration of inequities at a national level could aid future guidance of health policy and augment current vision screening programs.

Refractive amblyopia among children aged 4-12 years in a hospital-based setting in Gaza Strip, Palestine

Background

Refractive amblyopia is the most common cause of amblyopia in the Gaza Strip. However, the pattern of this condition has not yet been studied in this region. This study aimed to determine the pattern of refractive amblyopia in Gazan children aged 4‒12 years.

Methods

This was a hospital-based cross-sectional study using a purposive sampling method. Children aged 4‒12 years who attended the Children's Unit at Gaza Ophthalmic Hospital, Gaza Strip, Palestine from September 2019 to July 2020, were examined. A comprehensive eye test was conducted for all participants. Those who failed the eye examinations and were diagnosed with refractive amblyopia were included in the study. Demographic data and amblyopic refractive error patterns were analyzed accordingly.

Results

Of the 107 children, 72.9% were newly diagnosed with refractive amblyopia. The mean (standard deviation [SD]) of age of the children who participated was 7.85 (1.55) years. Approimately two-thirds of the patients were female (57.9%). Unilateral amblyopia was predominant in 60.7% of the cases. Moderate amblyopia was common (81.9%). A total of 149 amblyopic eyes were examined in total, with a mean (SD) (range) of best-corrected distance visual acuity and spherical equivalent of 0.45 (0.19) (0.2 to 1.3) logarithm of the minimum angle of resolution and + 0.76 (4.51) diopters (- 10.25 to + 11.50). Astigmatism was the most common amblyogenic factor (53.7%) among children with amblyopia.

Conclusions

The frequency of refractive amblyopia was 72.9%, and meridional amblyopia accounted for the highest percentage. Girls were more commonly affected than boys. The majority were in the 7-year-old age group. Most cases were unilateral with moderate refractive amblyopia. Our study yields insights into the patterns of refractive amblyopia among children in the Gaza Strip.

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

Background

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

Methods

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

Ethics and dissemination

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

Trial registration

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

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05735-2.

Delayed Diagnosis of Amblyopia in Children of Lower Socioeconomic Families: The Hong Kong Children Eye Study

AIMS

To determine the prevalence of amblyopia and the factors associated with delayed diagnosis among school-aged children in Hong Kong.

METHODS

Completed comprehensive ophthalmoscopic examinations were conducted among 4.273 children aged 6-8 years in the population-based Hong Kong Children Eye Study. New and previous diagnoses of amblyopia were identified. Socioeconomic status was surveyed through questionnaires.

RESULTS

According to criteria from the Multi-Ethnic Pediatric Eye Disease Study (MEPEDS), amblyopia was present in 43 out of 4,273 children (1.01%; 95% CI, 0.71-1.31). Among them, 33 (0.77%) were newly detected cases that were more likely from families living in Public Rental Housing or subdivided flats (OR, 4.22; P = .012), with lower paternal (OR 6.68, P = .008) and maternal education levels (OR, 4.38; P = .039). Multivariate analysis revealed associations of amblyopia with hyperopia (≥+2.00D; OR, 6.23; 95% CI, 2.86-13.56, P < .001), astigmatism (≥+2.00D; OR, 24.88; 95% CI, 10.69-57.91, P < .001) and anisometropia (≥2.00D; OR, 14.49; 95% CI, 5.93-37.63, P < .001).

CONCLUSION

These children with delayed diagnoses of amblyopia were more likely to come from lower socioeconomic backgrounds. Public education aimed at increasing awareness and utilization of child vision screening among such families is needed.

Reduced Photoreceptor Outer Segment Layer Thickness and Association with Vision in Amblyopic Children and Adolescents with Unilateral High Myopia

PURPOSE

To quantitatively compare reflectivity and other morphological changes of the photoreceptors of normal eyes with amblyopic eyes using the longitudinal reflectance profile (LRP) on swept-source optical coherence tomography (SS-OCT) images in children and adolescents with unilateral high myopia. The relationships between OCT parameters and visual acuity were investigated.

METHOD

Twenty-six amblyopes with unilateral high myopia and 34 age-, axial length- and spherical equivalent-matched normal controls were recruited. All participants underwent SS-OCT and detailed ophthalmic investigations. The reflectivity of the outer retinal and photoreceptor outer segment layer thickness were quantified by LRP using ImageJ software. All parameters were measured at three selected regions: at the fovea, 1 mm nasal to the fovea and 1 mm temporal to the fovea. Differences between the groups were evaluated.

RESULTS

The mean choroidal thickness was thinner in amblyopic eyes compared with controls (165.19 ± 59.02 μm vs 214.97 ± 66.41 μm at the fovea; 128.77 ± 57.06 μm vs 161.54 ± 57.37 μm at 1 mm nasal to the fovea; 188.13 ± 59.51 μm vs 219.87 ± 61.78 μm at 1 mm temporal to the fovea, P < .05). The amblyopic eyes had higher reflectivity of the ellipsoid zone at 1 mm nasal to the fovea only (85.41 ± 25.78 vs 70.76 ± 18.69, P = .02). The mean length of the photoreceptor outer segment (OS) layer was significantly greater in the control eyes than in the amblyopic eyes at all three regions (20.19 ± 1.89 vs 18.70 ± 2.23 at the fovea, P = .006; 16.06 ± 1.47 vs 15.07 ± 1.30 at 1 mm nasal to the fovea, P = .008; 15.81 ± 1.58 vs 14.56 ± 1.87 at 1 mm temporal to the fovea, P = .006). The shortened OS length was associated with poorer visual acuity.

CONCLUSION

The results of this study revealed that the amblyopes with unilateral high myopia had thinner choroidal thickness and shortened OS thickness compared to normal controls. The findings indicate that abnormal anatomic changes in the amblyopic children and adolescents with unilateral high myopia were not only due to high myopia but more likely due to a combination of high myopia and amblyopia.

Children with Disabilities/Special Health Needs and Ocular Refractive Disorders

Children with special needs face many eye problems that should be promptly addressed. Many eye diseases can be treatable if discovered in infancy. There is data showing these children have a higher prevalence of refractive errors than their non-disabled peers. If diagnosed and treated promptly, refractive errors can provide a good quality of life for special needs children.

Review on current concepts of myopia and its control strategies

Myopia poses a significant burden on the healthcare system, economy and quality of life. It is an emerging global public health challenge and requires interventions to delay or stop onset and progression. With changing times and evidence, the concepts of myopia are changing along with the treatment and control strategies. Behavioural modifications including increased outdoors time and reduced near work, optical and pharmaceutical management options are reviewed. This paper presents a current overview on the concepts of myopia, and is expected to summarize updates on myopia control methods.

Effectiveness of the Spot Vision Screener in screening 3-year-old children with potential amblyopia in Japan

PURPOSE

The purpose of this study was to compare the efficiency of conventional screening and of the Spot™ Vision Screener (SVS)-based screening in detecting potential cases of amblyopia during the Visual examination in Three-Year-Old Health Screening Program (VTYOS), that need to be referred for comprehensive examination.

STUDY DESIGN

Population-based cross-sectional study METHODS: This study introduced the SVS-based test to the VTYOS (which includes primary, secondary, and comprehensive examinations) of Sagae, Yamagata Prefecture, Japan. Children aged 3 years 6 months scheduled to undergo the secondary examination were subjected to both the SVS-based (evaluation of refractive error and eye alignment) and conventional screening test (questionnaire and visual acuity evaluation). Success rates, proportion of children who needed a comprehensive examination, rates of actual comprehensive examinations, and positive predictive value were determined and compared between conventional screening and SVS-based screening.

RESULTS

There were 294 participants; the rate of success of SVS-based screening (99.7%) was higher than conventional screening (89.5%, p < 0.01). The proportion of participants found to need a comprehensive examination according to SVS-based findings (7.5%) was lower than that according to conventional screening-based findings (23.5%, p < 0.01). The positive predictive value of the SVS-based screening test (75.0%) was higher than that of the conventional screening test (31.6%, p < 0.01). SVS-based screening detected 2 cases of amblyopia in 225 cases that passed conventional screening.

CONCLUSION

The VTYOS should ideally add SVS-based screening to conventional screening.

Prevalence of amblyopia and its determinants in a rural population: a population-based cross-sectional study

To determine the prevalence of amblyopia and its determinants in underserved rural villages of Iran. This population-based cross-sectional study was conducted in 3850 subjects selected from two underserved districts in the north (Kojur District, Nowshahr County, Mazandaran Province) and southwest (Shahyun District, Dezful County, Khuzestan Province) of Iran using multi-stage cluster sampling. The subjects underwent complete ophthalmic examinations including the measurement of uncorrected (UCVA) and best-corrected (BCVA) visual acuity, objective and subjective refraction, unilateral and alternate cover tests and ocular health examination. Amblyopia was defined as a reduction of BCVA to 20/30 or less in one eye or a 2-line interocular optotype acuity difference in the absence of any pathological factors. Of 3850 selected subjects, 3314 participated in the study (response rate = 86.08%). The mean age of the participants was 36.90 ± 20.21 years (range: 3-93 years). The prevalence and 95% confidence interval of total, bilateral, and unilateral amblyopia were 2.73% (2.17 to 3.38), 0.50% (0.28 to 0.83), and 2.23% (1.73 to 2.83), respectively. The most common type of amblyopia was anisometropic followed by strabismic and mixed. The lowest and highest prevalence was seen in the age group 6-20 years (1.36%; 0.65 to 2.49) and above 70 years (5.97%; 3.02 to 10.44), respectively. According to the results of multiple logistic regression analysis, compared to illiterate subjects, the odds ratio of amblyopia was 0.321 (P = .033) in subjects with High school education, 0.181 (P = .030) in subjects with secondary School education, and 0.486 (P = .041) in subjects with primary school education. The odds ratio of amblyopia for north villages residence vs southwest villages residence was 2.105 (P = .012). The odds ratio of amblyopia was 2.765 for age group>70 years vs. 6-20 years (P = .033). The prevalence of amblyopia was higher in north region, in participants with lower education level and older individuals. The high prevalence of amblyopia in older people may be due to the lack of screening programs in previous generations and consequently the lack of timely diagnosis and treatment.

The prevalence of lower eyelid epiblepharon and its association with refractive errors in Chinese preschool children: a cross-sectional study

Background

To assess the prevalence and demographics of lower eyelid epiblepharon in Chinese preschool children and to evaluate its association with refractive errors.

Methods

In this population-based, cross-sectional study, a total of 3170 children aged 3 to 6 years from Beijing, China underwent examinations including weight, height, cycloplegic autorefraction and slit-lamp examination of external eyes. The prevalence of lower eyelid epiblepharon in preschool children was evaluated and its association with age, sex, body mass index (BMI), and refractive errors was analyzed using logistic regression analysis.

Results

The prevalence of lower eyelid epiblepharon was 26.2%, which decreased with age, with prevalence in 3-, 4-, 5-, and 6-year-olds of 30.6, 28.0, 15.0, and 14.3%, respectively. Boys had a higher risk of having epiblepharon than girls (OR = 1.41; 95%CI, (1.20–1.66)) and no significant correlation was detected between BMI and epiblepharon after adjusting for age and sex (p = 0.062). Epiblepharon was significantly associated with a higher risk of refractive errors, including astigmatism (OR = 3.41; 95% CI, (2.68–4.33)), myopia (OR = 3.55; 95% CI, (1.86–6.76)), and hyperopia (OR = 1.53; 95% CI, (1.18–1.99)).

Conclusions

There is a high prevalence of lower eyelid epiblepharon in Chinese preschool children, particularly among boys and younger children. Preschoolers with lower eyelid epiblepharon are subject to a higher risk of developing astigmatism, myopia, and hyperopia, than those without. Increased attention should be paid to this eyelid abnormality in the preschool population.

Prevalence and determinants of refractive status and related ocular morbidity among Indian school children in Riyadh, Saudi Arabia

PURPOSE:

We present the magnitude and determinants of refractive status of Indian school children in Riyadh, Saudi Arabia.

METHODS:

This cross-sectional study was conducted in 2017–18 at a preparatory and secondary Indian school in Riyadh. A “Spot Screener” was used to determine if the child passed or failed a refraction test. Data were collected on refractive status in each eye, amblyopia, and strabismus. The type of refractive error (RE) was estimated and association to the gender, age group, and higher education was analyzed.

RESULTS:

We examined 770 students. The prevalence of RE in Indian school children was 50.3% (95% confidence interval [CI]: 51.3; 58.3). There were 51.1% of boys and 49.3% of girls. The prevalence of RE in preparatory and secondary grade students was 47.9% and 56.8%, respectively. The proportion of myopia and hyperopia among children with RE was 48% and 5%, respectively. Family history of RE was positively associated to RE in school children (odds ratio: 1.5 [95% CI: 1.1; 2.0]). The existing refractive services provided 47.4% coverage for children with RE. The current screening initiative could identify 22 (2.9%) new cases of RE who required visual aids and 38 (4.9%) students who needed a new prescription for RE. The compliance rate for using visual aid among students with RE was 78.9%. The prevalence of amblyopia and strabismus was 1.2% and 11%, respectively.

CONCLUSION:

A high proportion of Indian school students in Riyadh have RE. Periodic ocular assessment and refractive services are recommended for this group of school children.

Effects of congenital ptosis on the refractive development of eye and vision in children

AIM

To investigate the influence of unilateral congenital ptosis on the development of the eye and vision in children.

METHODS

In this prospective observational study, 41 patients with unilateral congenital ptosis were enrolled (age range 3-15y). The blepharoptosis was divided into 3 subgroups according to the margin reflex distance-1 (MRD-1), including mild group (MRD-1≥2 mm), moderate group (0≤MRD-1<2 mm), and severe group (MRD-1<0 mm). The fellow eyes served as controls. All subjects underwent ocular examinations, including axial length, keratometry, and refractive error.

RESULTS

The incidence of astigmatism (ptotic eyes: 58.5% vs fellow eyes: 24.4%, P=0.002) and magnitude of cylindrical power (ptotic eyes: -0.86±0.79 D vs fellow eyes: -0.43±0.63 D, P=0.003) differed significantly between the ptotic eyes and the fellow eyes. The spherical equivalent refraction (P=0.006), spherical power (P=0.01), cylindrical power (P=0.011), axial length-corneal radius (AL/CR) ratio (P=0.009), frequency of hyperopia (P=0.002) and astigmatism (P=0.004) were significantly different among the ptotic eye subgroups and the fellow eye group. In addition, in patients with congenital ptosis, the incidence of amblyopia is 43.9% and the incidence of anisometropia is 24.4%. More importantly, the ratio of AL/CR showed significantly positive correlation with the severity of ptosis (P=0.002).

CONCLUSION

Congenital ptosis may lead to a delayed eyeball development in the aspect of AL/CR. The risk of amblyopia is also increased due to visual deprivation and aggravated anisometropia, particularly in severe ptosis case.

Associations between Poor Vision, Vision-Related Behaviors and Mathematics Achievement in Chinese Students from the CNAEQ-PEH 2015

Purpose: Poor vision is prevalent in school-aged students, especially in East Asia. This can not only cause irreversibly physical health impairments like glaucoma and cataracts, but also the loss of individual education and employment opportunities and deterioration of the quality of life. The present study aims to investigate the associations between poor vision, vision-related risk behaviors, and mathematics achievement in youth from China. Methods: The present study included a total of 106,192 Grade 4 students and 70,236 Grade 8 students from the China National Assessment of Educational Quality-Physical Education & Health 2015 (CNAEQ-PEH 2015). We conducted a standard logarithmic visual acuity scale for vision screening, a self-reported questionnaire for vision-related risk behavior and a standardized mathematics assessment for mathematics performance. Poor vision is defined as the visual acuity below 5.0 by using the standard logarithmic visual acuity chart. Linear regression was conducted. Results: The prevalence rate of poor vision in China was 37.1% in Grade 4 and 66.2% in Grade 8 in 2015. Students who had poor vision were more likely to have better mathematics achievement than those with normal vision. Reading in bed, insufficient sleep, and screen time during weekdays and weekends were associated with higher odds of poor vision. Conclusions: Poor vision was positively associated with mathematics academic achievements, while vision-related risk behaviors such as screen time, homework time and reading in bed were associated with a high prevalence of poor vision in compulsory education cycle students.

Prevalence, incidence and risk factors of strabismus in a Chinese population-based cohort of preschool children: the Nanjing Eye Study

AIMS

To evaluate the prevalence, incidence and their related risk factors of strabismus among preschool children in China.

METHODS

Children born between September 2011 and August 2012 in Yuhuatai District of Nanjing were invited to participate in the Nanjing Eye Study for a comprehensive eye examination annually since 2015. The data presented in this paper were obtained from 2015 to 2017, when these children grew from the age of 3 to 5 years. Eye examinations included visual acuity, anterior segment, posterior segment, refraction, and ocular alignment and motility. Risk factors were evaluated using univariable and multivariable logistic regression models for prevalent and incident strabismus.

RESULTS

In 2015, a total of 2018 children (87.7% response rate) of 2300 eligible preschoolers completed the baseline eye examination when they were 3 years old. Among the 2018 participants, 50 had strabismus (prevalence rate, 2.48%). In multivariable analysis, prevalent strabismus was independently associated with parental strabismus history (OR=11.60, p<0.001), hyperopia (OR=6.22, p<0.001), prematurity (OR=3.07, p=0.01) and astigmatism (OR=2.15, p=0.04). Among 1766 children followed up for 2 years, 63 developed strabismus (annual incidence rate, 1.78%), of whom 57 had exotropia and 6 had esotropia. In multivariable analysis, incident strabismus was significantly associated with parental strabismus history (OR=5.55, p=0.04) and prematurity (OR=3.77, p<0.001).

CONCLUSIONS

In this population-based cohort study, we found a higher incidence of strabismus and a higher exotropia:esotropia ratio than previous studies in preschool children. Parental strabismus history and prematurity were associated with a higher risk for both prevalent and incident strabismus.

High prevalence of myopia in children and their parents in Hong Kong Chinese Population: the Hong Kong Children Eye Study

PURPOSE

To determine the myopia prevalence in Hong Kong Chinese children and their parents.

METHODS

It was a population-based cross-sectional study. A total of 4257 children aged 6-8 years, and 5880 parents were recruited in the Hong Kong Children Eye Study. Cycloplegic autorefraction was measured for children; and non-cycloplegic autorefraction for parents. Parental educational level, children's outdoor time, and near work were collected by validated questionnaires.

RESULTS

In children aged 6-8 years, 25.0% were myopic, and among them, 12.7% for the 6-year-olds, 24.4% for the 7-year-olds and 36.1% for the 8-year-old. About 0.7% of children aged 8 years were high myopia. In all age groups, boys (their myopia rate: 13.9% at 6 years, 26.7% at 7 years, and 38.3% at 8 years) were more myopic than girls (11.3% at 6 years, 22.0% at 7 years, 33.4% at 8 years). Among parents, 72.2% were myopic (mother, 73.2%; father, 70.7%) and 13.5% high myopia (mother, 12.8%; father, 14.5%). It was observed that prevalence decreased with ages and increased with education level.

CONCLUSION

There is a strikingly high prevalence of myopia in Hong Kong children aged 6-8, much higher than that of other regions of China. Of note, the prevalence of children was similar to that in 15 years ago. Furthermore, the myopia prevalence of parents is high, and it had already increased in this cohort. Prevention of childhood myopia is important, likewise for visual complications from high myopia in adults.

Prevalence and pattern of amblyopia in a rural hospital in Ghana

Amblyopia is a developmental ocular disease of childhood-onset which may lead to persistent sequelae into adulthood. Early detection and management of amblyopia usually result in an improved visual outcome. The purpose of this study was to determine the prevalence and pattern of amblyopia in a rural hospital in Ghana. Clinical records of patients seen (from January 2014 to December 2018) at Westphalian Medical Center, Oyoko, Ashanti Region, Ghana, were reviewed retrospectively. Unilateral amblyopia was defined as a two-line interocular difference or more in visual acuity. Bilateral amblyopia was defined as best-corrected visual acuity (BCVA) of Snellen 6/12 or worse in both eyes, with evidence of bilateral ametropia or obstruction of the visual pathway. Following a review of 12,602 patient records, 258 cases of amblyopia were identified. The mean (±SD) presenting age of amblyopic patients was 24.3 ± 16.1 years, with a male-to-female ratio of 1:1.1. The period prevalence of amblyopia was 2.04%. The period prevalence of unilateral and bilateral amblyopia was 1.38% and 0.66%, respectively. The most prevalent form of amblyopia was refractive with a cumulative prevalence of 1.42%. Strabismic and stimulus deprivation amblyopia accounted for 0.36% and 0.21% of all amblyopic cases, respectively. A major cause of amblyopia in this population was refractive error, hence the use of spectacle correction for its initial management. Repeated assessment after an appropriate period of refractive adaptation would elucidate the proportion of amblyopias needing additional treatment modalities. Vision screening for early detection of amblyopia in childhood with accessible and effective management of amblyopia (including refractive correction and occlusion treatment) is necessary to reduce the impact of amblyopia in Ghana.

Influence of prenatal environment and birth parameters on amblyopia, strabismus, and anisometropia

PURPOSE

To report the prevalence of amblyopia, strabismus, and anisometropia in a young adult population at a single center in Australia and to investigate the underlying prenatal and early-life risk factors.

METHODS

Participants in the Raine Study have been followed from mid-gestation (n = 2,868 newborns) to young adulthood. At age 20 years, 1,344 participants had a comprehensive eye examination, including visual acuity and a detailed orthoptic assessment. Risk factors were determined from medical records and questionnaires completed by the mothers at 18 weeks' gestation. The main outcome measures were the proportions of participants with amblyopia, esotropia, exotropia, or anisometropia (defined as >1 D difference).

RESULTS

Of the 1,125 white participants, 12 (1.1%) had amblyopia, 39 (3.5%) had strabismus, and 33 (2.9%) had anisometropia. In multivariable logistic regression, amblyopia was associated with a maternal history of pregnancy-induced hypertension (OR = 3.80; 95% CI, 1.19-12.13); esotropia, with lower gestational age (OR = 0.97; 95% CI, 0.95-0.97) and a heavier placenta (OR = 1.02; 95% CI, 1.00-1.04); exotropia, with a maternal history of previously treated hypertension (OR = 4.00; 95% CI, 1.06-15.03) and maternal use of recreational drugs during early pregnancy (OR = 3.61; 95% CI, 1.06-15.03); and anisometropia, with older maternal age (OR = 1.07; 95% CI, 1.01-1.14) and an abnormal umbilical cord (OR = 2.39; 95% CI, 1.04-5.47).

CONCLUSIONS

The prevalence of amblyopia, strabismus, and anisometropia in this cohort was similar to that in other studies. Preterm birth and maternal health may have adverse effects on eye development.

Objective Assessment of the Effect of Optical Treatment on Magnocellular and Parvocellular-biased Visual Response in Anisometropic Amblyopia

Purpose

Optical treatment can improve visual function in anisometropic amblyopia, but there is no electrophysiological evidence, and the underlying change in visual pathway remains unknown. Our aims were to characterize the functional loss in magnocellular and parvocellular visual pathways in anisometropic amblyopia at baseline and to investigate the effect of optical treatment on the 2 visual pathways.

Methods

Using isolated-check visual-evoked potential, we measured the magnocellular- and parvocellular-biased contrast response functions in 15 normal controls (20.13 ± 3.93 years; mean ± standard deviation), 16 patients with anisometropic amblyopia (18.00 ± 6.04 years) who were fully refractive corrected before and 29 (19.41 ± 7.41 years) who had never been corrected. Twelve previously uncorrected amblyopes received optical treatment for more than 2 months and finished the follow-up measurement.

Results

Both the magnocellular- and parvocellular-biased contrast response functions in the amblyopic eye exhibited significantly reduced response and weaker contrast gains. We also found that the uncorrected amblyopes showed a more severe response reduction in magnocellular-biased, but not parvocellular-biased condition when compared with those corrected, with a weaker initial contrast gain and lower maximal response. After optical treatment, 12 uncorrected amblyopes demonstrated improved visual acuity of the amblyopic eye and a significant response gain to magnocellular-biased but not parvocellular-biased stimuli.

Conclusions

We demonstrated deficits to both magnocellular- and parvocellular-biased stimuli in subjects with anisometropic amblyopia. Optical treatment could produce neurophysiological changes in visual pathways even in older children and adults, which may be mediated through the magnocellular pathway.

Effect of a complex intervention to improve post-vision screening referral compliance among pre-school children in China: A cluster randomized clinical trial

BACKGROUND

We investigated whether specific appointments for quality-assured care could increase referral uptake, often low in China, in children's vision screening.

METHODS

We randomized children aged 4-7 years in Yudu, Jiangxi, China, by school to Control (free school-based eye screening, parents of children failing screening recommended for further examination [usual practice]) or Intervention (identical examinations, with parents additionally provided with specific appointments for further examinations by quality-assured doctors at a designated local hospital). Both groups could select any hospital for referral exams, which were not free. Six months after screening, parents were interviewed on referral compliance at any hospital (primary outcome) and potential determinants. This trial is registered at the ClinicalTrials.gov, number NCT03251456.

FINDINGS

Among 9936 children at 63 schools randomized to Intervention (32 schools, 5053 [50·9%] children) or Control (31 schools, 4883 [49·1%] children), 1114 children (11·2%) failed screening. Among 513 referred Intervention children (46·1%, 32 schools, mean age 5·36 years, 53·0% boys) and 601 referred Control children (53·9%, 31 schools, mean age 5·30 years, 57·7% boys), 104 (20·3%) and 135 (22·5%) were lost to follow-up respectively. Under Intention to Treat analysis, assuming children lost to follow-up were non-compliant, Intervention children had significantly higher compliance than Controls (308/513 = 60·0% vs. 225/601 = 37·4%, P < 0·001). In regression models, Intervention group membership (Relative risk [RR] 1·53, 95% confidence interval, 1·36-1·72), travel time to hospital (RR: 0·97, 0·95-0·999), baseline glasses wear (RR: 1·37, 1·17-1·60), strabismus (RR: 1·17, 1·01-1·36) and worse uncorrected vision (RR: 1·41, 1·03-1·92) were associated with compliance.

INTERPRETATION

Providing specific appointments for quality-assured eye care improved referral compliance in this setting.

Global prevalence of amblyopia and disease burden projections through 2040: a systematic review and meta-analysis

Purpose

Amblyopia is a leading cause of vision impairment among children and young adults. Individual studies showed significant variations in the prevalence of amblyopia in different regions and age groups. This study is to estimate the global prevalence of amblyopia by pooling its prevalence from the previous studies and to project the number of people affected through 2040.

Methods

We performed a systematic review and meta-analysis on the prevalence of amblyopia using data published before 20 October 2018. We estimated the prevalence rate of amblyopia and its 95% CI globally and by subgroups (eg, region and age). The prevalence data were applied to United Nations World Population Prospects to derive the projected number with amblyopia through 2040.

Results

A meta-analysis of 60 studies (1 859 327 subjects) showed that the pooled prevalence rate of amblyopia was 1.44% (95% CI 1.17% to 1.78%). Prevalences in Europe (2.90%) and North America (2.41%) were higher than in Asia (1.09%) and Africa (0.72%). The highest prevalence was found in subjects over 20 years old (3.29%). There was no difference in the prevalence between genders. We estimated 99.2 (95% CI 71.7 to 146.1) million people with amblyopia in 2019 worldwide, increasing to 175.2 (95% CI 81.3 to 307.8) million by 2030 and 221.9 (95% CI 83.7 to 429.2) million by 2040.

Conclusions

The amblyopia is becoming a significant vision problem worldwide. It is of great importance to design and implement amblyopia screening, treatment and related public health strategies.

Prevalence of visual impairment and refractive errors in an urban area of Mexico

AIM

To determine the distribution of refractive errors in a school-age population in Quintana Roo (Mexico) in the framework of an international cooperation campaign for the prevention of blindness.

METHODS

A sample of 2647 school-age children (ranging from 5 to 14 years old) with a mean age of 9.1±1.9 years old were tested by trained volunteers for distance visual acuity (VA) and refractive errors. The first screening examination included uncorrected distance visual acuity (UDVA) and VA with a +2.00 D lens. Inclusion criteria for a second complete cycloplegic eye examination performed by an optometrist were UDVA <20/25 (0.10 logMAR or 0.8 decimal) and/or VA with +2.00 D ≥20/25.

RESULTS

A total of 633 (23.9%) children underwent the second complete eye examination. Mean logMAR UDVA was 0.035±0.094 (range 1.00 to 0.00 logMAR) for the right eyes and 0.036±0.160 (range 1.00 to 0.00 logMAR) for the left eyes. Bilateral amblyopia was found in 17 children (2.7% of refracted eyes; 0.64% of the total). The main reason for visual impairment (VI) in the sample analyzed was found to be refractive errors. In 12 children (1.9% of refracted eyes; 0.45% of the total) the VI was bilateral and 9 (1.4% of refracted eyes; 0.34% of the total) achieved a corrected distance visual acuity of 20/25 or better in both eyes. Mean magnitude of sphere and refractive cylinder was +0.20±0.96 D and -0.43±0.85 D in right eyes, and +0.24±1.08 and -0.43±0.83 D in left eyes. The proportion of myopic eyes [standard equivalent (SE) ≤-0.50 D] was 4.6% of the whole sample (5290 eyes). The mean magnitude of myopia was -0.84±3.44 D for the right eyes and -0.82±5.21 D for the left eyes. The proportion of hyperopic patients (SE≥+2.00 D) was 2.4% (15/633), which corresponded to 0.60% of the whole sample (32/5290 eyes). No statistically significant correlation of age to manifest sphere or cylinder was found.

CONCLUSION

VI due to uncorrected refractive errors can be easily corrected with glasses but it is still a burden to be treated. Myopia is prevalent in this sample. More efforts towards correcting uncorrected refractive errors are needed.

Comparison of amblyopia in schoolchildren in Ireland and Northern Ireland: a population-based observational cross-sectional analysis of a treatable childhood visual deficit

OBJECTIVES

This study reports the prevalence of persistent amblyopia (post-traditional treatment age) in schoolchildren in the Republic of Ireland (henceforth Ireland) and Northern Ireland (NI), UK; populations with broadly similar refractive and genetic profiles but different eye-care systems.

DESIGN

This is a population-based observational study of amblyopia and refractive error.

SETTING

Recruitment and testing in primary and post-primary schools in Ireland and NI.

PARTICIPANTS

Two groups identified through random cluster sampling to represent the underlying population; Ireland 898 participants (12-13 years old) and NI 723 participants (295 aged 9-10 years old, 428 aged 15-16 years old).

MAIN OUTCOME MEASURES

Monocular logMAR visual acuity (presenting and pinhole), refractive error (cycloplegic autorefraction), ocular alignment (cover test) and history of previous eye care. These metrics were used to determine prevalence and type of amblyopia and treatment histories.

RESULTS

Children examined in NI between 2009 and 2011 had a significantly lower amblyopia prevalence than children examined in Ireland between 2016 and 2018 (two-sample test of proportions, p<0.001). Using a criteria of pinhole acuity 0.2logMAR (6/9.5 Snellen) plus an amblyogenic factor, 4 of 295 participants aged 9-10 years old (1.3%, 95% CIs 0.4 to 3.6) and 3 of 428 participants aged 15-16 years old (0.7%, 95%CIs 0.2 to 2.2) were identified in NI. The corresponding numbers in Ireland were 40 of 898 participants aged 12-13 years old (4.5%, 95% CI 3.2 to 6.1). In NI strabismic amblyopia was the most prevalent type of persistent amblyopia, whereas anisometropic was predominant in Ireland. In Ireland, amblyopia was associated with socioeconomic disadvantage (OR=2.2, 95%CIs 1.4 to 3.6, p=0.002) and poor spectacle compliance (OR 2.5, 95% CIs 2.0 to 3.2, p<0.001).

CONCLUSIONS

Amblyopia prevalence persisting beyond traditional treatment ages was significantly lower among NI children compared with Ireland. Uncorrected anisometropia, compliance with spectacle wear and socioeconomic disadvantage were contributing factors in Ireland. Children without obvious visible eye defects were less likely to access eye care in Ireland, resulting in missed opportunities for intervention where necessary.

Prevalence of amblyopia in congenital blepharoptosis: a systematic review and Meta-analysis

AIM

To conduct a systematic review and Meta-analysis of the published literature to evaluate the pooled prevalence rate of amblyopia in patients with congenital ptosis.

METHODS

We searched the PubMed, Embase, the Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, Wanfang Data, and Chongqing VIP databases for studies reporting the prevalence of amblyopia in patients with congenital ptosis. The reference lists of relevant studies were scanned. Heterogeneity of effect sizes across studies was tested. We calculated prevalence ratios to compare prevalence estimates for different causes of amblyopia in patients with congenital ptosis, as well as for different geographical regions, year of publication and sample size in subgroup analyses. A systematic review and Meta-analysis were performed.

RESULTS

We identified 29 eligible surveys with a total population of 2436. Prevalence rates of amblyopia ranged from 13.8% to 69%. We noted substantial heterogeneity in prevalence estimates for amblyopia in congenital ptosis (Cochran's χ ² significant at P<0.0001; I ²=90%). The pooled prevalence using random-effects models of 29 studies was 32.8% (95%CI: 27.3%-38.4%) in the overall population. Compared to the overall pooled prevalence, amblyopia prevalence was higher in studies in which only subjects with blepharophimosis syndrome were included.

CONCLUSION

We confirm that nearly one-third of congenital ptosis patients are suffering from or at risk for amblyopia. Patients with blepharophimosis syndrome are more likely to develop amblyopia. The identification and management of amblyopia should be integral to the treatment of congenital ptosis.

Prevalence of visual impairment among school children in three primary schools of Sekela Woreda, Amhara regional state, north-west Ethiopia

Background

Although there are limited studies, recent data are lacking to determine the prevalence of eye problems in Ethiopia accurately and there is no scientific evidence of such study in Sekela Woreda. The purpose of this study was to determine the prevalence of visual impairment among school children in Sekela Woreda, Ethiopia.

Methods

The study design was a community-based analytical cross-sectional with a multi-stage cluster random sampling technique from September to November 2016.Visual acuity was tested using Snellen's "E" chart while color vision was tested using Ishihara chart. The data were analyzed using SPSS version 20 software, and binary logistic regression was used to identify factors associated with visual impairment.

Results

A total of 875 participants, 466 (53.3%) males and 409 (46.7%) females, with an age range of 8-18 years were screened for visual acuity and color vision deficiency. The prevalence of visual impairment (visual acuity ⩽ 6/12) in "either eye" was 70 (8.0%). Among these, 37 (52.9%) were males and 33 (41.1%) were females. The prevalence of low vision (visual acuity ≤ 6 / 36 ) and blindness (visual acuity < 3/60) in "either eye" were 28 (3.2%) and 10 (1.1%), respectively. Thirty two (3.7%) had mild visual impairment ( v i s u a l a c u i t y ≤ 6 / 12 t o ≥ 6 / 18 ) . The prevalence of color vision deficiency was 36 (4.1%). Among these, 27 (3%) were males and 9 (1.1%) were females. The variables age (adjusted odds ratio (95% confidence interval) = 1.14 (1.01-1.28) and color blindness (adjusted odds ratio (95% confidence interval) = 3.93(1.69-9.09) were significantly associated with visual impairment.

Conclusion

The prevalence of blindness and low vision in school children were higher than the national prevalence in Ethiopia. Increasing age and color defective vision were factors associated with the children's visual impairment. The Woreda health office ought to work with responsible stakeholders to tackle the situation in early childhood.

Visual problems: a review of prevalence studies on visual impairment in school-age children

Childhood visual impairment (VI) have a significant impact on the educational achievement, career choices and social life of affected individual, and in children, is mainly due to either preventable or treatable causes. Reliable data on the prevalence and causes of VI in children will guide the development of a systematic vision screening program for its early detection and successful treatment of possible causes. The purpose of this literature review is to summarize the available data on prevalence and causes of VI in school-age children from various regions globally. A discussion on the major findings highlighting the definition criteria, classifications and limitations for further studies is also presented.

Clinical Profile and Treatment Outcomes of Amblyopia Across Age Groups

PURPOSE

The purpose is to study the clinical profile of amblyopia by age at diagnosis.

SUBJECTS AND METHODS

A retrospective chart review of 327 amblyopic patients over 7 years (September 2009-December 2016) was performed, divided by age at diagnosis into four groups: <3, 3-7, 8-15, and >15 years. Demographics, eye conditions and eye examination parameters including visual acuity (VA), refractive errors, and motility measurements were collected.

RESULTS

Mean age at diagnosis and follow-up time was 6.2 ± 6.1 years standard deviation (SD) and 12.4 months ± 20.6 SD, respectively. The most common overall cause of amblyopia was strabismus (37%) followed by anisometropia (36%). The main causes by age at diagnosis were: strabismus at <3 years, anisometropia at 3-7 years, anisometropia at 8-15 years, and mixed at >15 years. Significant improvement in VA with treatment was noted with age between 3 and 15 years (3-7 years, P = 0.001 and 8-15 years, P = 0.03).

CONCLUSIONS

Strabismus was the main cause of amblyopia at <3 years of age; anisometropia was more prevalent in older children (3-15 years). The fact that more than a quarter of our amblyopic patients were detected late (after the age of 8 years) underscores the need for expanded vision screening measures in young children.

Prevalence of amblyopia and strabismus in Hani school children in rural southwest China: a cross-sectional study

PURPOSE

To determine the prevalence rate of amblyopia and strabismus in Chinese Hani ethnic school-aged children.

METHODS

All grade 1 and grade 7 students in Mojiang Hani Autonomous County, located in southwest China, were invited for comprehensive eye examinations performed by experienced ophthalmologists and optometrists, including visual acuity, ocular alignment and movements, cycloplegic autorefraction, anterior segment and fundus examinations. Standard definitions of amblyopia and strabismus were applied to calculate their prevalence rate.

RESULTS

A total of 1656 (91.0% response rate) grade 1 Hani students and 1394 (92.8% response rate) grade 7 Hani students participated in the study. Amblyopia was present in 25 Hani students (0.82%, 95% CI 0.55% to 1.20%), with no significant differences in grade (p=0.42) and gender (p=0.69). Among these 25 amblyopic children, 17 had unilateral amblyopia and eight had bilateral amblyopia, including 16 anisometropic, eight binocular refractive and one strabismic. Strabismus was found in 59 Hani students (1.93%, 95% CI 1.50% to 2.48%), including 47 with intermittent exotropia, six with constant exotropia, five with constant esotropia and one with unilateral superior oblique palsy. The prevalence rate of strabismus was higher in grade 7 students than grade 1 students with borderline significance (2.44%vs1.50%, p=0.07), but was similar by gender (2.16% in boys vs 1.68% in girls, p=0.36).

CONCLUSION

The prevalence of amblyopia and strabismus in Chinese Hani school children are both lower than that previously reported for Chinese Han children in China and for many other racial/ethnic populations from non-China studies. Refractive error is the major cause for amblyopia and intermittent exotropia is the primary strabismus type.