Visual acuity, residual amblyopia and ocular pathology in a screened population of 12-13-year-old children in Sweden

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.

[Visual acuity in German preschool children-results of a cross-sectional study]

Hintergrund

Im Rahmen der kinderärztlichen Vorsorgeuntersuchungen U1 bis U9 von der Geburt bis zum Beginn des sechsten Lebensjahres wird unter anderem das Sehvermögen getestet – eine augenärztliche Vorsorgeuntersuchung im Kindesalter gibt es in Deutschland nicht. Diese Studie untersucht, ob eine Teilnahme an der U8 (am Ende des vierten Lebensjahres) und der U9 (zu Beginn des sechsten Lebensjahres) mit Sehschärfeergebnissen assoziiert ist, die im Rahmen der Schuleingangsuntersuchungen (SEU) erhoben werden.

Methoden

Ausgewertet wurden Daten der SEU des Landes Rheinland-Pfalz der Einschulungsjahrgänge 2009/2010 bis 2014/2015. In diesen Jahrgängen wurde die Sehschärfe mittels Rodenstock-Sehtestgerät (E-Haken; Rodenstock Instrumente GmbH, Ottobrunn, Deutschland) und eigener Korrektur geprüft. Festgehalten wurden reduzierte Sehschärfen von <0,7. Der Zusammenhang zwischen der Teilnahme an den Vorsorgeuntersuchungen U8 bzw. U9 und dem Vorliegen einer ein- und beidseitigen Sehschärfe <0,7 bei SEU wurde mithilfe von multipler logistischer Regressionsanalyse untersucht und für wichtige Störgrößen adjustiert.

Ergebnisse

Daten von 189.704 Kindern (91.041 Mädchen und 98.663 Jungen) aus 35 von 36 Landkreisen konnten eingeschlossen werden. Eine Sehschärfe <0,7 wurde bei 8416 Kindern (4,4 %) ermittelt, in beiden Augen bei 4345 (2,3 %) Kindern. Die Teilnahmequote an der U8 bzw. U9 betrug 93,9 % bzw. 93,3 %. Es bestand eine negative Assoziation zwischen der Teilnahme an der U8 bzw. U9 und einem ein- oder beidseitigen SEU-Visus <0,7 (adjustierte OR: 0,68; 95 %-KI: 0,61–0,75; p < 0,01; N = 124.467/adjustierte OR: 0,57; 95 %-KI: 0,51–0,65; p < 0,01; N = 121.496).

Schlussfolgerungen

Es zeigt sich ein hoher Anteil an Kindern mit verminderter Sehschärfe bei der Schuleingangsuntersuchung. Kinder, die in der U8 und U9 untersucht worden waren, hatten eine bessere Chance für eine gute Sehschärfe bei der Schuleingangsuntersuchung.

Impaired visual acuity caused by uncorrected refractive errors and amblyopia in a German paediatric cohort

PURPOSE

This study describes the prevalence of visual impairment caused by uncorrected distance refractive error and the spectacle coverage in a large cohort of German children and adolescents. Furthermore, we determined the prevalence of amblyopia and amblyopia treatment.

METHODS

Optometrists carried out visual acuity (VA) testing, non-cycloplegic autorefraction, VA retesting with the refractive correction obtained by autorefraction, and if necessary subjective refraction and cover-test in 1,874 subjects (901 girls/973 boys), aged 3 to 16 years. Additionally, a questionnaire on the history of previous eye care was completed.

RESULTS

Distance visual impairment (VI) with VA worse than 6/18 Snellen in the better eye was present in 0.5% (95% confidence interval [95% CI]: 0.2% to 0.9%) of children. Logistic regression showed a significant positive association between VI and older age (OR = 1.21, P = 0.03). Gender differences were not found (P = 0.77). The spectacle coverage of all participants was 74.8% (95% CI: 65.2% to 82.8%). Amblyopia was found in 29 participants (1.5%; 95% CI: 1.0% to 2.2%) with no age or sex differences. The causes of unilateral amblyopia (27 cases, 93.1%) were anisometropia in 55.6% of children, strabismus in 25.9% and the combination of these factors in 18.5%. All children with bilateral amblyopia (2 cases, 6.9%) showed bilateral high ametropia. We observed 15 children with current amblyopia, who had been treated with occlusion therapy in the past (62.2%; 95% CI: 42.7% to 83.6%).

CONCLUSIONS

The prevalence of impaired VA caused by uncorrected refractive error and amblyopia is comparable with previous studies conducted in urban areas worldwide. Adding the measurement of refractive error to existing medical check-ups, possibly using autorefraction, would be desirable.

A systematic review of Amblyopia prevalence among the children of the world

Objective: to assess the prevalence of Amblyopia disease in the children of the world. Methods: In order to perform this systematic review, PICO was considered as the research question. Then, the preferred keywords were searched in Medline (via PubMed), Embase, Scopus, Web of Science, and ProQuest databases. The retrieved citations were reviewed by two independent inspectors in a three-step process in terms of the title, abstract, and full-text, based on the inclusion criteria. The studies included in the review were critically evaluated and then were extracted by two dependent expert reviewers. Finally, the prevalence of Amblyopia disease in the children of the world was pooled by meta-analysis CMA v.2 software. The heterogeneity of the selected studies was evaluated using I2 and chi-square. Also, subgroup-analysis was performed using designs and continents. Results: Out of 952 retrieved citations, 131 studies were included. The total prevalence of Amblyopia in the children of the world was calculated to be 4.3% [Pooled Prevalence: 4.3%, 95% CI: 2.6%-7.00%, P-value 0.0001]. In addition, the heterogeneity of the studies was reported to be high (Q: 48281.18, df: 56, p-value 0.001, I-square: 99.88). The subgroup analysis showed that America had the highest (5.57%, 95% CI: 2.23%-13.94%, P-value 0.0001) prevalence, and the lowest prevalence of Amblyopia in the children of the world was seen in Africa (7.1%, 95% CI: 0.003%-172.53%, P-value 0.05). Conclusion: It can be concluded that the total prevalence of Amblyopia is 3.4%, but this estimate varies in all continents, especially in Africa. The major reason for this variation was reported to be the heterogeneity of studies. These assessments have investigated different populations in terms of severity of illness, age, and gender. Therefore, further worldwide high-quality and valid studies should be carried out to allow the calculation of the real prevalence of Amblyopia among children of the world. Abbreviations: VA = visual acuity, ALSPAC = Avon Longitudinal Study of Parents and Children, JBI = Joanna Briggs Institute, PRISMA = Systematic Review and Meta-analysis, CMA = Comprehensive Meta-analysis Software.

No Benefit of a Pediatric Screening in Discovering Reduced Visual Acuity in Children: Experiences from a Cross-Sectional Study in Germany

BACKGROUND

The newly introduced German pediatric screening examination at the end of the third year of life (U7a) incorporates visual function testing in particular; there is no ophthalmic screening during childhood in Germany. The purpose of this study is to investigate the relationship between participation in U7a and visual function at the preschool health examination (PHE) in the sixth year of life.

METHODS

This study evaluated PHE data from school enrollment years 2009/2010 to 2014/2015 of Rhineland-Palatinate, Germany. Visual acuity (VA) at PHE was assessed with Rodenstock visual acuity test device (tumbling E) wearing glasses if present. The relationship between participation in U7a and VA <0.7 at PHE was calculated for reduced monocular and binocular VA using multiple logistic regression adjusted for potential confounders.

RESULTS

Data from 189,704 children (91,041 girls) in 35 out of 36 districts were included. The first children to participate in U7a were enrolled in 2011/2012 school year. In total, 90,339 children (47.6%) had U7a before PHE, while 99,365 (52.4%) had not. VA <0.7 in at least one eye was measured at PHE in 8429 (4.4%) children, and in both eyes in 4345 (2.3%) children. Participation in U7a was not associated with VA <0.7 at PHE (odds ratio 0.99; 95% confidence interval: 0.94-1.04).

CONCLUSIONS

The proportion of children with VA <0.7 at PHE was high. No beneficial effect of newly introduced German U7a pediatric screening examination was found for reduced VA at PHE.

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.

Sensitivity and specificity of the red reflex in Costa Rican newborns

OBJECTIVE

To compare the results of indirect ophthalmoscopy versus determination of the red reflex in newborns admitted to the intermediate neonatal intensive care unit.

METHODS

All the patients (71) admitted to the intermediate neonatal intensive care unit from July to September of 2017 were screened with the red reflex. Immediately afterwards, they were pharmacologically dilated and indirect ophthalmoscopy was performed. All of the red-reflex screening and the funduscopic examination were performed by the same evaluator.

RESULTS

A total of 14.1% (20/142) of the eyes had an altered red reflex. Indirect ophthalmoscopy revealed that 21.8% (31/142) of the eyes had intraocular abnormalities. Two of these eyes had optic nerve colobomas, two eyes had cataracts, and the rest had intra-retinal haemorrhages. Indirect ophthalmoscopy revealed that only 35% (7/20) of the eyes with an altered red reflex had intraocular disease. Indirect ophthalmoscopy also revealed that intraocular disease was present in 77.4% (24/31) of the eyes despite a normal red reflex. The false positive rate of the red reflex was calculated to be 9.2%, and the false negative rate was 16.9%. The sensitivity of the red reflex was only 56.4%, and the specificity was 89.5%. The positive predictive value was 70.4%, and the negative predictive value was 82.2%.

CONCLUSIONS

Neonatal screening with the red reflex is not sufficient to detect intraocular disease. A normal neonatal red reflex does no exclude intraocular disease. It has a specificity of nearly 90%, but its sensitivity is only 56%. Most retinal haemorrhages are undiagnosed as they cannot be detected with a red reflex.

The Danish Rural Eye Study: prevalence of strabismus among 3785 Danish adults - a population-based cross-sectional study

PURPOSE

To determine the prevalence of strabismus among Danish adults and to find the frequency of history of strabismus and strabismus surgery. Furthermore, to evaluate the prevalence of strabismus-associated amblyopia among participants with strabismus and to relate the results to the current national vision screening programme.

METHODS

In total, 3785 adults in the Danish Rural Eye Study underwent an interview regarding eye health, visual acuity measurement, Hirschberg test and retinal photography. Participants were categorized into groups based on their birth date in relation to the introduction of the national vision screening programme.

RESULTS

In total, the prevalence of strabismus was 1.1% (41/3785; 95% CI: 0.8-1.5); no differences were found in relation to gender or screening status. The prevalence of exotropia (XT) was 0.3% (12/3785; 95% CI: 0.2-0.6) and of esotropia (ET) 0.8% (29/3785; 95% CI: 0.5-1.1), resulting in an XT:ET ratio of 1:2.7. A history of strabismus was present in 4.6% (174/3785; 95% CI: 4.0-5.3), and a history of strabismus surgery was present in 0.8% (32/3785; 95% CI: 0.6-1.2) of the participants. Among participants with manifest strabismus, 24% had strabismus-associated amblyopia.

CONCLUSION

In this first European population-based study of strabismus prevalence in adults, the prevalence was similar to three out of five previous studies using cover test. The use of Hirschberg test may have led to an underestimation of the true prevalence. The prevalence was neither related to screening status nor gender. Our results are the first to display a predominance of ET among Caucasian Scandinavian adults.

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.

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.

Evaluation of vision screening in five- to eight-year-old children living in Region Västra Götaland, Sweden - a prospective multicentre study

PURPOSE

To evaluate the current vision screening criteria regarding amblyopia and refractive errors, with emphasis on screening limits and retesting, in Region Västra Götaland (VGR), Sweden. Visual acuity (VA) screening is performed by nurses at primary healthcare centres (PHCs) in 4-year-old children and at school in 6- or 7-year-old children. Children with VA <0.65 (>0.19 logMAR) at either eye are referred. If VA is 0.65 in one or both eyes, a retest is performed by nurses at PHCs and schools, the children are then referred if VA is <0.8 (>0.10 logMAR).

METHODS

We included all children aged ≥5 and <8 years referred between October 2014 and June 2015 from PHCs and schools to the four eye clinics in VGR, with VA ≥0.65 in one or both eyes. At the eye clinic, children underwent assessment of VA, refraction in cycloplegia, eye motility, cover test, stereo test and a slit lamp examination.

RESULTS

Among the 259/295 children (139 female) participating, median age was 5.7 years (5.0-7.8 years) at referral. Glasses were prescribed due to subnormal VA with refractive errors in 20% of the children, 22% displayed heterophoria, none had heterotropia and one younger child had amblyopia. Accurate retesting gave fewer false-positive referrals.

CONCLUSION

Our results showed that a vision screening referral cut-off limit of VA <0.65 would leave undetected refractive errors. Residual amblyopia was uncommon. Accurate referral criteria, retesting and training of those performing the screening as well as re-evaluation of the screening programme are all important.

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.

Visual acuity and amblyopia prevalence in 11- to 12-year-old Danish children from the Copenhagen Child Cohort 2000

PURPOSE

To evaluate the prevalence of amblyopia and associated biometric factors in Danish children.

METHODS

Determination of best-corrected visual acuity (BCVA) using ETDRS charts, non-cycloplegic subjective refractioning guided by automated refractometry, axial length and corneal curvature, fundus photography and optical coherence tomography (OCT) in 1335 children from the population-based Copenhagen Child Cohort 2000 (CCC2000) Eye Study. Birth data were obtained from the Danish Medical Birth Registry.

RESULTS

The mean (±SD) age of children was 11.7 (±0.4) years, and 47% were boys. Amblyopia prevalence was 1.5 (95% CL 0.8-2.2) %. Unilateral amblyopic eyes [BCVA < 80 ETDRS letters (0.8 snellen) and ≥2 lines difference between the eyes] was 0.6 (95% CL 0.3-1.0) mm shorter, 1.34 (95% CL 0.30-2.37) D more hyperopic and had 0.79 (95% CL 0.14-1.44) D more astigmatism compared with fellow eyes. Compared with the right eyes of the non-amblyopic children, unilateral amblyopic eyes were 1.0 (95% CL 0.5-1.6) mm shorter, 2.48 (95% CL 1.11-3.86) D more hyperopic, 1.09 (95% CL 0.43-1.75) D more astigmatic and had a 47 (95% CL 13-81) μm thicker subfoveal choroid.

CONCLUSION

Amblyopia was found in 1.5% of Danish children born 22 years after the inception of the nationwide preschool visual screening programme. Amblyopia was associated with anisometropia, astigmatism, a thicker subfoveal choroid and a history of childhood strabismus.

Prevalence of amblyopia in Bulgaria

Introduction: The purpose of this study was to establish the prevalence of amblyopia in children, aged 4 to 10 years, in Bulgaria, who underwent a complete eye examination.Methods: The study was designed as cross-sectional epidemiological study, and the results were calculated in percentages. A complete ophthalmological examination was performed on 1,675 children, aged 4 to 10 years (mean age 7.7 years), during the period 01 Feb 2017-21 April 2017, in five cities, in the western part of Bulgaria. All children were verbal, none of them had a neurologic deficit or mental development delay and a complete examination was successfully performed. The ophthalmological examination consisted of: autorefractometry (using pediatric autorefractor with infrared photoretinoscopy), visual acuity, best-corrected visual acuity (BCVA) and visual acuity with pinhole occluder, cover/uncover and alternate cover test, Worth four-dot test, stereopsis, biomicroscopy and funds examination. Amblyopia was defined as reduction of the BCVA for near and far distances under 40/60 on one or on both eyes in the absence of any pathology of the eye, excluding a pathology leading to stimulus deprivation amblyopia, and in the presence of an amblyogenic factor.Results: Out of 1,675 children, 42 (2.5%) were diagnosed with amblyopia: 7% had strabismic amblyopia (3), 59% had anisometropic amblyopia (25), 31% had isoametropic amblyopia (13), and 3% deprivation amblyopia (1). Unilateral amblyopia was diagnosed in 73% (27) of the cases and bilateral amblyopia in 27% (15). For 45% (754) of the children, it was their first visit to an ophthalmologist.Conclusions: The prevalence of amblyopia among these patients (2.5%) is correlating well with the expected, based on data from other authors, between 1.5% and 3.5%. The fact that nearly half of the children (45%) have not been examined by an ophthalmologist is, however, alarming. The lack of a national screening program in Bulgaria could be the main reason. Other factors include: insufficient number of pediatric ophthalmologists in the country and the lack of awareness among the parents.

Ophthalmological data on 4.5- to 7-year-old Danish children

PURPOSE

To report normative data on visual acuity (VA) for near and distance, refraction, ocular alignment, ocular motility and stereo acuity in a cohort of children aged 4.5-7 years.

METHODS

A total of 950 children with normal development from the municipality of Roskilde, Denmark, were invited to participate in an ophthalmic cross-sectional population-based survey, of which 445 children in the age of 54-87 months participated with a complete ocular examination including cycloplegia. Visual acuity (VA) was tested using Kay Picture charts and notified in logMAR units.

RESULTS

Mean distance VA was 0.010 logMAR [standard deviation (SD): 0.048] in right eye, and near VA in right eye was 0.012 logMAR (SD: 0.054), with a nonsignificant difference between right and left eye in both parameters (paired t-test, p = 0.15 and p = 0.08, respectively). Amblyopia was found in 12 children (2.7%), mainly related to refractive errors. The mean refractive error of right eye was +1.75 D, and significant hyperopia (greater than +3.0 D) was found in 7.9%. No myopia (greater than or equal to -0.5 D) was found, astigmatism (>1 D) was seen in 4.3%. Manifest strabismus was present in 1.6%, and heterophoria in 4.0%. Reduced or absent stereo acuity was present in 35 children (7.9%) and was related to a reduced VA, refractive error and strabismus.

CONCLUSION

Ophthalmic data of 445 normally developed children are presented, supplementing previous reported normative data in children. We found a relatively high prevalence of amblyopia and of hyperopia, while myopia was not found, confirming previous studies that myopia is not developing at early age in Danish children.

Refractive and ocular biometric profile of children with a history of laser treatment for retinopathy of prematurity

PURPOSE

Indian children belong to a diverse socioeconomic strata with retinopathy of prematurity (ROP) developing in mature, higher birth weight babies as well. The purpose of our study is to analyze the long-term status of refractive errors and its relationship with ocular biometry in children with ROP who were laser treated at a tertiary center in North India.

METHODS

Cross sectional study. Children (<16 years) enrolled from January 2014 to December 2014 with a history of laser treatment for ROP and examined for refractive and biometric status.

RESULTS

Thirty-six children presenting to us at the mean age of 7.37 ± 3.07 years (6-15 years) were included. Mean spherical equivalent (SE) was -4.05 D ± 5.10. 75% were myopic, with high astigmatism in 31%. Higher lens thickness (P = 0.03) and higher SE (P = 0.002) at 1 year postnatal age were predictors of larger SE. 79.4% achieved a favorable functional outcome (visual acuity ≥20/40). 5.88% achieved unsatisfactory outcome (<20/200) despite having a favorable structural outcome.

CONCLUSION

There are a substantial number of children who develop myopia and high astigmatism while undergoing laser treatment for ROP. We found myopia in our cohort to be lenticular and greater axial length contributing to the development of high myopia. An initial large refractive error predicts the future development of myopia in these children. Nearly 6% of patients with good structural outcome have unexplained subnormal vision. Our threshold for prescribing glasses in these children should be low.

Ophthalmologic Outcomes of Children Born Premature Without ROP: Correlations With Gestational Age and Psychomotor Development

PURPOSE

To study ophthalmological outcomes of premature children with no retinopathy of prematurity (ROP) and correlate with neurodevelopmental outcomes.

METHODS

A total of 69 former preterm infants were evaluated at 2 to 7 years of age. Detailed ophthalmologic examinations were performed. Neurodevelopment was assessed using the Peabody Developmental Motor Scale and Wechsler Preschool and Primary Scale of Intelligence. Another 69 healthy children served as controls.

RESULTS

The 69 preterm children (38 of 69 boys) and 69 controls (38 of 69 boys) had a mean age of 4.9 ± 1.5 and 4.9 ± 1.4 years, respectively. Compared to controls, preterm infants had vision impairment of 19% versus 1.4% (P = .001), hyperopia of 87% versus 98.5% (P = .21), myopia of 11% versus 1.4% (P = .017), and astigmatism of 39% versus 30.4% (P = .37). Children with any motor disability tended to have worse vision.

CONCLUSIONS

In the absence of ROP, hyperopia was more common in infants 32 weeks or older who weighed more than 1,500 g at birth; other vision problems were similar in subgroups. This may represent impending myopia in those younger than 32 weeks weighing less than 1,500 g. [J Pediatr Ophthalmol Strabismus. 2017;54(1):32-38.].

Amblyopia in Children: Analysis Among Preschool and School Children in the City of Tuzla, Bosnia and Herzegovina

Aim:

This study measured the prevalence of amblyopia in preschool and school children between 4 and 15 years of age in Tuzla, Bosnia and Herzegovina and as well and to examine its relations with anisometropia and strabismus.

Methods:

Children from eight daycare centers and twenty four elementary schools were screened for amblyopia by volunteer personnel (medical students), any child who failed to pass the screening examination, was referred to the ophthalmologist for complete examination at University Clinic Center Tuzla. The examination included VA, stereopsis, cover testing, refractive retinoscopy, and examination of the red reflex and posterior pole.

Results:

Total of 7415 children, which included 3790 males and 3625 females, in the age range of 3 to 15 years from 24 schools and 8 preschool were screened. Fifty night children (1.9%) were diagnosed with amblyopia, unilateral in 28 and bilateral in 31.

Conclusion:

Prevalence of significant refractive errors is high enough to justify a school eye screening program solely for this purpose. preschool and school screening program in children in critical period of development of amblyopia must be conducted to find out the ametropias and amblyopia in time; and treat them earlier.

Zagreb Amblyopia Preschool Screening Study: near and distance visual acuity testing increase the diagnostic accuracy of screening for amblyopia

AIM

To present and evaluate a new screening protocol for amblyopia in preschool children.

METHODS

Zagreb Amblyopia Preschool Screening (ZAPS) study protocol performed screening for amblyopia by near and distance visual acuity (VA) testing of 15 648 children aged 48-54 months attending kindergartens in the City of Zagreb County between September 2011 and June 2014 using Lea Symbols in lines test. If VA in either eye was >0.1 logMAR, the child was re-tested, if failed at re-test, the child was referred to comprehensive eye examination at the Eye Clinic.

RESULTS

78.04% of children passed the screening test. Estimated prevalence of amblyopia was 8.08%. Testability, sensitivity, and specificity of the ZAPS study protocol were 99.19%, 100.00%, and 96.68% respectively.

CONCLUSION

The ZAPS study used the most discriminative VA test with optotypes in line as they do not underestimate amblyopia. The estimated prevalence of amblyopia was considerably higher than reported elsewhere. To the best of our knowledge, the ZAPS study protocol reached the highest sensitivity and specificity when evaluating diagnostic accuracy of VA tests for screening. The pass level defined at ≤0.1 logMAR for 4-year-old children, using Lea Symbols in lines missed no amblyopia cases, advocating that both near and distance VA testing should be performed when screening for amblyopia.

Whole-population vision screening in children aged 4-5 years to detect amblyopia

Amblyopia is a neurodevelopmental disorder that affects at least 2% of most populations and can lead to permanently reduced vision if not detected and treated within a specific period in childhood. Whole-population screening of children younger than 5 years is applied in many countries. The substantial diversity in existing programmes reflects their heterogeneous implementation in the absence of the complete evidence base that is now a pre-requisite for instituting screening. The functional importance of amblyopia at an individual level is unclear as data are scarce, but in view of the high prevalence the population-level effect might be notable. Screening of all children aged 4-5 years (eg, at school entry) confers most benefit and addresses inequity in access to timely treatment. Screening at younger ages is associated with increased risk of false-positive results, and at older ages with poor outcomes for children with moderate to severe amblyopia. We suggest that the real-life adverse effects of amblyopia should be characterised and screening and diagnosis should be standardised.

The usefulness of the Retinomax autorefractor for childhood screening validated against a Danish preterm cohort examined at the age of 4 years

BACKGROUND AND PURPOSE

Refractometers have gained a foothold in childhood screening for ophthalmic disorders. Given the results of an ophthalmic follow-up of an extremely preterm Danish cohort, the results of the Retinomax autorefractor were further evaluated.

MATERIALS AND METHODS

A nationwide cohort of infants born before gestational age 28 weeks (n=178) and 56 term controls were examined at the age of 4 years. Refraction was given as the cycloplegic Retinomax value. For this study, we analysed the equipment's confidence value on the printout and equipment-induced myopization (as the difference between refraction measured before and after topical cyclopentholate 1%), both items hypothetical with a view to having identified factual ophthalmic deviations.

RESULTS

Thirty-two of 42 eyes with visual acuity ≤0.4 had high Retinomax confidence values (8-9); the Retinomax values were also high in 10 of 12 children with strabismus and lack of stereopsis. Low values (1-6) were recorded in 11 single eyes, 5 of which were normal (false positives). Three children already known to have low vision were unable to cooperate. The overall mean value for equipment-induced myopization was 1.9 D (range, 0-6.87 D). Myopization showed no correlation with visual acuity and corneal curvature, and a weak positive correlation with refractive value disappeared when the myopic outliers were excluded.

CONCLUSIONS

The hand-held Retinomax seemed to be reliable for assessing refraction in 4-year-old children, provided a cycloplegic agent is applied; if used alone, the Retinomax would have missed several cases of ophthalmic deviation during screening. Equipment-induced myopization was not indicative.

Ophthalmological findings in 10-year-old full-term children--a population-based study

PURPOSE

To determine different ophthalmological parameters in 10-year-old, healthy, full-term children in Stockholm County, Sweden.

METHODS

Two hundred and seventeen children were included in the study. Best-corrected distance and near visual acuities (VA) were measured using logMAR charts. Cycloplegic retinoscopy was performed, and spherical equivalent and astigmatism were determined. Examination of ocular movement and cover test for distance and near were performed. Stereopsis was assessed with the TNO test, and contrast sensitivity with the Vistech test. The Royal Air Force rule was used for assessing accommodation, and near point of convergence was measured with the Lang fixation stick. Ophthalmoscopy was performed through dilated pupils.

RESULTS

Eighty-two per cent of the children had a distance VA of -0.1 logMAR (1.3 Snellen acuity) or better. None of the children were visually impaired [VA>0.6 logMAR (<0.3 Snellen acuity)]. Ninety-three per cent had a near VA of -0.1 logMAR (1.25 Snellen acuity) or better. Mean spherical equivalent was 0.6 D. Eight (3.6%) children had hypermetropia (≥+2 D), and 17 (7.8%) were myopic (≤-0.5 D). Nine (4.1%) children had an astigmatism≥1 D, and two (0.9%) had anisometropia of ≥1 D. Manifest strabismus was found in seven (3.2%) children, five of whom had exotropia. Heterophoria for distance and/or near was found in 80.2% of the children. In children without manifest strabismus, stereopsis>60 seconds of arc was found in five (2.4%). Three (1.4%) of 215 children had contrast sensitivity below normal limits. Binocular median near point of accommodation was 14 D, and median near point of convergence 6 cm.

CONCLUSION

Knowledge of various visual functions in normally developing children is crucial to be able to draw conclusions from ophthalmological examinations in children with eye diseases. This population-based study describes different ophthalmological parameters in full-term ten-year-old children. The material can be used as a control when examining children of similar ages with various ophthalmological conditions, such as groups of children with specific neurological or retinal diseases, and syndromes.

Prevalence of amblyopia and strabismus in a population of 7th-grade junior high school students in Central China: the Anyang Childhood Eye Study (ACES)

PURPOSE

To determine the prevalence of amblyopia and strabismus in 7th-grade junior high school students in central China.

METHODS

Using stratified cluster sampling, 2363 7th-grade students were recruited from four junior high schools in Anyang city into the cross-sectional Anyang Childhood Eye Study (ACES). All students underwent visual acuity (VA), cycloplegic autorefraction, cover test, and ocular movement examinations. Uncorrected VA and best-corrected VA (BCVA) were measured with a logarithm of the minimum angle of resolution (logMAR) chart. Cycloplegic autorefraction was performed after administration of 1.0% cyclopentolate and Mydrin-P. Strabismus was defined as heterotropia at near or distance fixation. Amblyopia was defined as BCVA ≤ 0.1 logMAR units in one or both eyes, without ocular pathology in either eye.

RESULTS

Of the 2363 eligible students, 2260 (95.6%) completed all examinations. The mean age of the students was 12.4 ± 0.6 years. Amblyopia was present in 52 students (2.5%), of whom 33 (63.5%) had unilateral and 19 (36.6%) had bilateral amblyopia. Of those with unilateral amblyopia, 18 (54.5 %) had anisometropia and 7 (21.2%) had strabismus. Of those with bilateral amblyopia, 6 (31.6%) had significant refractive error. Strabismus was present in 108 students (5.0%), of whom 2 (1.9%) had esotropia, 102 (94.4%) had exotropia, 3 (2.8%) had vertical strabismus, and 1 (0.9%) had microstrabismus. Of the 108 students with strabismus, 9 (8.3%) had amblyopia.

CONCLUSION

The cross-sectional ACES which examined the prevalence of amblyopia and strabismus in 7th-grade students in central China revealed the prevalence of strabismus, particularly the proportion of exotropia, to be higher than previously reported.

Alcohol use and positive screening results for depression and anxiety are highly prevalent among Chinese children with strabismus

PURPOSE

To study associations between strabismus and alcohol use, anxiety, and depression among 10- to 17-year-old children in Guangdong, southern China.

DESIGN

Cross-sectional, population-based study.

METHODS

Among 7537 children aged 6-17 years from 9 randomly selected primary and middle schools, ocular alignment was assessed with the Hirschberg light reflex, cover-uncover testing, and alternate cover testing at distance (6 m) and near (40 cm). Additionally, 4000 children (53.1%) aged 10+ years received self-administered questionnaires containing screening questions on alcohol use, anxiety, and depression.

RESULTS

Examinations were completed on 7464 of 7537 subjects (99.0%), including 3928 boys (52.6%), with a mean age of 11.1 ± 1.8 years. The prevalence of any strabismus, including exotropia (2.7%), esotropia (0.2%), and intermittent exotropia (3.9%), was 6.8%. Strabismus was more prevalent in urban students (7.3%) and female subjects (7.4%) compared to rural students (6.0%) and male subjects (6.2%) (all P < .05). In multivariate regression models, any strabismus was associated with older age and rural vs urban residence. Among 3903 children (97.6%) answering questionnaires, history of alcohol use (62.3% vs 36.3%) and positive screening responses for depression (26.0% vs 11.6%) and anxiety (10.3% vs 4.9%) were significantly (P < .01 for all) more common among children with strabismus.

CONCLUSION

These Chinese children with strabismus had a significantly higher prevalence of alcohol use and possible markers of emotional problems than children without strabismus. Further research should focus on the appropriateness of classifying surgical treatment for strabismus as "cosmetic" (ineligible for reimbursement) under China's rural health insurance.

Prevalence, causes and associations of amblyopia in year 1 students in Central China : The Anyang childhood eye study (ACES)

BACKGROUND

Earlier diagnosis and treatment of amblyopia are associated with improved visual outcomes. This study reports the prevalence of amblyopia and associated factors in year 1 primary school students in central China.

METHODS

The school-based, cross-sectional study involved 3,112 year 1 primary school students . All the participants underwent a comprehensive eye examinations including cycloplegic refraction, cover test and ocular movement examinations. The unaided and best corrected visual acuity (BCVA) was recorded. Unilateral amblyopia was defined as a 2-line interocular difference with BCVA ≤ 20/32 (≥ logMar 0.2) in the worse eye and with coexisting anisometropia (≥ 1.00 D SE for hyperopia, ≥ 3.00 D SE for myopia, or ≥ 1.50 D for astigmatism), strabismus or past or present visual axis obstruction. Bilateral amblyopia was defined as BCVA in both eyes<20/40 (> logMar 0.3), with coexisting hyperopia ≥ 4 D SE, myopia ≤ -6 D SE, or astigmatism ≥ 2.5 D, or past or present visual axis obstruction.

RESULTS

Out of the 3,112 eligible students, 2,893 (93.0 %) students completed the examinations. The average age of the students was 7.1 ± 0.4 (mean ± standard deviation SD) years old. The prevalence of amblyopia was 1.0 % (95 % confidence interval [CI], 0.6 %-1.3 %) with no difference between the sexes (P = 0.88). Of the 27 amblyopic students, unilateral amblyopia was found in 18 (66.7 %) students, and bilateral amblyopia in 9 (33.3 %) students. Of 18 unilateral amblyopia, 13 were anisometropic amblyopia, 4 were strabismus amblyopia, 1 was mixed amblyopia. Of 9 bilateral amblyopia, 7 were isoametropic amblyopia, 2 were stimulus deprivation. The mean corrected VA of the amblyopic eyes was 30.50 logMAR letters (Snellen VA equivalent 4/12.6), and the range was 5 to 45 logMAR letters (Snellen VA equivalent 4/40-4/6.3). Most amblyopic eyes (38.9 %) were significantly hyperopic (spherical equivalent ≥ +3.00 D); 25.0 % were myopic. In addition, 58 (2.1 %) students had a previous amblyopia history of amblyopia that was not corroborated in this study.

CONCLUSIONS

The study shows a relatively low prevalence of amblyopia (1.0 %) in year 1 students in central China. Amblyopia is usually caused by abnormal refractive error.

Albinism: particular attention to the ocular motor system

The purpose of this report is to summarize an understanding of the ocular motor system in patients with albinism. Other than the association of vertical eccentric gaze null positions and asymmetric, (a) periodic alternating nystagmus in a large percentage of patients, the ocular motor system in human albinism does not contain unique pathology, rather has "typical" types of infantile ocular oscillations and binocular disorders. Both the ocular motor and afferent visual system are affected to varying degrees in patients with albinism, thus, combined treatment of both systems will maximize visual function.

The relationship between anisometropia and amblyopia

This review aims to disentangle cause and effect in the relationship between anisometropia and amblyopia. Specifically, we examine the literature for evidence to support different possible developmental sequences that could ultimately lead to the presentation of both conditions. The prevalence of anisometropia is around 20% for an inter-ocular difference of 0.5D or greater in spherical equivalent refraction, falling to 2-3%, for an inter-ocular difference of 3D or above. Anisometropia prevalence is relatively high in the weeks following birth, in the teenage years coinciding with the onset of myopia and, most notably, in older adults starting after the onset of presbyopia. It has about one-third the prevalence of bilateral refractive errors of the same magnitude. Importantly, the prevalence of anisometropia is higher in highly ametropic groups, suggesting that emmetropization failures underlying ametropia and anisometropia may be similar. Amblyopia is present in 1-3% of humans and around one-half to two-thirds of amblyopes have anisometropia either alone or in combination with strabismus. The frequent co-existence of amblyopia and anisometropia at a child's first clinical examination promotes the belief that the anisometropia has caused the amblyopia, as has been demonstrated in animal models of the condition. In reviewing the human and monkey literature however it is clear that there are additional paths beyond this classic hypothesis to the co-occurrence of anisometropia and amblyopia. For example, after the emergence of amblyopia secondary to either deprivation or strabismus, anisometropia often follows. In cases of anisometropia with no apparent deprivation or strabismus, questions remain about the failure of the emmetropization mechanism that routinely eliminates infantile anisometropia. Also, the chronology of amblyopia development is poorly documented in cases of 'pure' anisometropic amblyopia. Although indirect, the therapeutic impact of refractive correction on anisometropic amblyopia provides strong support for the hypothesis that the anisometropia caused the amblyopia. Direct evidence for the aetiology of anisometropic amblyopia will require longitudinal tracking of at-risk infants, which poses numerous methodological and ethical challenges. However, if we are to prevent this condition, we must understand the factors that cause it to develop.

Visual acuity measures do not reliably detect childhood refractive error--an epidemiological study

Purpose

To investigate the utility of uncorrected visual acuity measures in screening for refractive error in white school children aged 6-7-years and 12-13-years.

Methods

The Northern Ireland Childhood Errors of Refraction (NICER) study used a stratified random cluster design to recruit children from schools in Northern Ireland. Detailed eye examinations included assessment of logMAR visual acuity and cycloplegic autorefraction. Spherical equivalent refractive data from the right eye were used to classify significant refractive error as myopia of at least 1DS, hyperopia as greater than +3.50DS and astigmatism as greater than 1.50DC, whether it occurred in isolation or in association with myopia or hyperopia.

Results

Results are presented from 661 white 12-13-year-old and 392 white 6-7-year-old school-children. Using a cut-off of uncorrected visual acuity poorer than 0.20 logMAR to detect significant refractive error gave a sensitivity of 50% and specificity of 92% in 6-7-year-olds and 73% and 93% respectively in 12-13-year-olds. In 12-13-year-old children a cut-off of poorer than 0.20 logMAR had a sensitivity of 92% and a specificity of 91% in detecting myopia and a sensitivity of 41% and a specificity of 84% in detecting hyperopia.

Conclusions

Vision screening using logMAR acuity can reliably detect myopia, but not hyperopia or astigmatism in school-age children. Providers of vision screening programs should be cognisant that where detection of uncorrected hyperopic and/or astigmatic refractive error is an aspiration, current UK protocols will not effectively deliver.

Prevalence of eye diseases and causes of visual impairment in school-aged children in Western China

Background

The present study investigated the prevalence of refractive error, visual impairment, and eye diseases in school-aged children in western China.

Methods

The survey was done in a representative county (Yongchuan District, Chongqing Municipality) of western China. Cluster random sampling was used to select children aged 6 to 15 years. We conducted door-to-door surveys and eye examinations including optometry, stereoscopic vision test, eye position and eye movement, slit lamp examination of the anterior segment, retinoscopy, and fundus examination after cycloplegia with 1% cyclopentolate.

Results

Among 3469 children, data were available for 3079 (88.76%). The prevalences of eye diseases were, in descending order, refractive error (20.69%; 637/3079), conjunctivitis (11.76%; 362/3079), amblyopia (1.88%; 58/3079), color vision defect (0.52%; 16/3079), keratitis (0.36%; 11/3079), strabismus (0.29%; 9/3079), cataract (0.23%; 7/3079), pathologic myopia (0.19%; 6/3079), and ocular trauma (0.13%; 4/3079). The prevalence of corneal leucoma, corneal staphyloma, optic neuropathy, macular degeneration, and myelinated nerve fibers was 0.03% (1/3079) for each. The prevalence of visual impairment was 7.70% (237/3079), and the major causes of visual impairment were uncorrected refractive error (86.08%; 204/237), amblyopia (9.70%; 23/237), pathologic myopia (1.27%; 3/237), congenital cataract (0.42%; 1/237), and others (2.11%; 5/237).

Conclusions

Among school-aged children in a less developed area of western China, refractive error was the most prevalent eye disorder, and uncorrected refractive error was the main cause of visual impairment.

Prevalence of amblyopia and strabismus in young singaporean chinese children

PURPOSE. To determine the prevalence of amblyopia and strabismus in young Singaporean Chinese children. METHODS. Enrolled in the study were 3009 Singaporean children, aged 6 to 72 months. All underwent complete eye examinations and cycloplegic refraction. Visual acuity (VA) was measured with a logMAR chart when possible and the Sheridan-Gardner test when not. Strabismus was defined as any manifest tropia. Unilateral amblyopia was defined as a 2-line difference between eyes with VA < 20/30 in the worse eye and with coexisting anisometropia (> or =1.00 D for hyperopia, > or =3.00 D for myopia, and > or =1.50 D for astigmatism), strabismus, or past or present visual axis obstruction. Bilateral amblyopia was defined as VA in both eyes <20/40 (in children 48-72 months) and <20/50 (<48 months), with coexisting hyperopia > or =4.00 D, myopia < or = -6.00 D, and astigmatism > or =2.50 D, or past or present visual axis obstruction. RESULTS. The amblyopia prevalence in children aged 30 to 72 months was 1.19% (95% confidence interval [CI], 0.73-1.83) with no age (P = 0.37) or sex (P = 0.22) differences. Unilateral amblyopia (0.83%) was twice as frequent as bilateral amblyopia (0.36%). The most frequent causes of amblyopia were refractive error (85%) and strabismus (15%); anisometropic astigmatism >1.50 D (42%) and isometropic astigmatism >2.50 D (29%) were frequent refractive errors. The prevalence of strabismus in children aged 6 to 72 months was 0.80% (95% CI, 0.51-1.19), with no sex (P = 0.52) or age (P = 0.08) effects. The exotropia-esotropia ratio was 7:1, with most exotropia being intermittent (63%). Of children with amblyopia, 15.0% had strabismus, whereas 12.5% of children with strabismus had amblyopia. CONCLUSIONS. The prevalence of amblyopia was similar, whereas the prevalence of strabismus was lower than in other populations.

Defining Amblyopia: The Need for a Joint Classification

Recent years have shown an impressive rise in high quality research on amblyopia. Unfortunately, the condition is not sufficiently defined, and consequently different studies have been used different definitions of amblyopia. Aspects in need of consideration include the degree of visual acuity reduction, magnitude of interocular difference in acuity, method of visual acuity testing used, the effect of refractive adaption, the presence of amblyogenic factors, the absence of organic cause and the treat ability of the deficit. Vision scientists worldwide are encouraged to jointly decide on what is, and what is not, amblyopia.

Vision screening for amblyopia in childhood

BACKGROUND

Amblyopia is a reversible deficit of vision that has to be treated within the sensitive period for visual development. Screening programmes have been set up to detect this largely asymptomatic condition and refer children for treatment while an improvement in vision is still possible. The value of such programmes and the optimum protocol for administering them remain controversial.

OBJECTIVES

The objective of this review was to evaluate the effectiveness of vision screening in reducing the prevalence of amblyopia.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 3, 2008), MEDLINE (January 1950 to August 2008) and EMBASE (January 1947 to August 2008). The electronic databases were last searched on 15 August 2008. No language restrictions were placed on these searches. No handsearching was done.

SELECTION CRITERIA

We planned to analyse data from randomised controlled trials and cluster-randomised trials comparing the prevalence of amblyopia in screened versus unscreened populations.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study abstracts identified by the electronic searches. Full text copies of appropriate studies were obtained and, where necessary, authors were contacted. No data were available for analysis and no meta-analysis was performed.

MAIN RESULTS

Despite the large amount of literature available regarding vision screening no trials designed to compare the prevalence of amblyopia in screened versus unscreened populations were found.

AUTHORS' CONCLUSIONS

The lack of data from randomised controlled trials makes it difficult to analyse the impact of existing screening programmes on the prevalence of amblyopia. The absence of such evidence cannot be taken to mean that vision screening is not beneficial; simply that this intervention has not yet been tested in robust trials. To facilitate such trials normative data on age-appropriate vision tests need to be available and a consensus reached regarding the definition of amblyopia. In addition, the consequences of living with untreated amblyopia have yet to be quantified and a cost-benefit analysis carried out.

Risk factors of ophthalmic disorders in children with developmental delay

PURPOSE

To identify diagnoses that increase the risk of ophthalmic disorders in developmentally delayed children.

METHODS

A cross-sectional study of 1126 Danish children with developmental delay (IQ <or= 80), aged 4-15 years [mean age 10 years 1 month; standard deviation (SD) 3 years 2 months; 702 boys, 424 girls]. Ophthalmological and paediatric data were obtained from 719 children. The relative risks (RRs) of ophthalmic disorders were calculated for low IQ, low birth weight, low gestational age, asphyxia, cerebral palsy (CP), epilepsy, neuroradiologically verified cerebral abnormalities, Down's syndrome and other genetic syndromes.

RESULTS

Adjusted RR showed that visual impairment was correlated to CP [RR 2.3, 95% confidence interval (CI) 1.3-4.2], epilepsy (RR 2.5, 95% CI 1.5-4.2), verified cerebral changes (RR 1.9, 95% CI 1.1-3.3) and Down's syndrome (RR 2.7, 95% CI 1.2-6.3). Adjusted RR showed that refractive errors were correlated to CP (RR 1.5, 95% CI 1.1-2.1) and Down's syndrome (RR 2.2, 95% CI 1.5-3.2). Adjusted RR showed that strabismus was correlated to cerebral changes (RR 1.8, 95% CI 1.2-2.5).

CONCLUSION

The RR of ophthalmic disorders in developmentally delayed children is increased if the child has CP, epilepsy, verified cerebral abnormalities or a genetic syndrome; referral for ophthalmological evaluation should be performed on suspicion of these conditions.

Long-term follow-up of visual functions in prematurely born children--a prospective population-based study up to 10 years of age

INTRODUCTION

Prematurely born children have an increased risk of ophthalmologic problems. There is still no consensus on how they should be followed. The purpose of this study was to evaluate predictive factors for problems in premature children at ten years of age and to discuss follow-up recommendations.

MATERIALS AND METHODS

One hundred ninety-nine children with a birth weight of 1500 g or less were screened for retinopathy of prematurity (ROP) in the neonatal period and thereafter ophthalmologically examined at 6 months, 1.5, 2.5, 3.5, and 10 years of age. "Visual dysfunction" at ten years of age was defined as visual acuity > or =0.1 logMAR and/or strabismus and/or subnormal contrast sensitivity. Multiple regression analyses were used to evaluate risk factors at an early age, which could predict problems at ten years of age.

RESULTS

Twenty-five percent of the cohort had visual dysfunction at ten years of age. Neurological complications, cryotreated ROP, anisometropia, and astigmatism were risk factors. The sensitivity was 75.5%, and the specificity 80.7% for the detection of visual dysfunction at ten years of age when all children with neurological complications, cryotreated ROP, strabismus, anisometropia > or =1 diopters (D) at 2.5 years, and astigmatism > or =2 D at 2.5 years were included in further follow-up.

CONCLUSIONS

Repeated ophthalmologic follow-up of prematurely born children should be performed in those with treated ROP and/or neurological conditions. For a third group without such problems, at least one follow-up is recommended. Such an examination also provides a good opportunity to identify neurological problems that warrant further ophthalmologic follow-up.

Long term ophthalmic sequelae of prematurity

There are numerous reports of an increase in refractive errors and amblyogenic factors in the low birth weight population relative to children born at full term. This raises the question of whether additional long term ophthalmic screening is required. The current provision of follow up care for preterm infants in the UK is haphazard and varies in terms of its availability, the type of assessment, age at assessment and age at discharge. This issue needs to be addressed to provide the best care for these children however there are different possible methodologies. One key aspect of a screening programme is the age at testing as this dictates the possible tests used which impacts on the efficacy. However, although the prevalence of strabismus and refractive errors is well documented the development of these conditions is poorly understood so for this and other reasons it is difficult to devise the most effective screening programme.

Visual outcomes and perinatal adversity

Preterm birth per se, the neonatal environment, retinopathy of prematurity (ROP) and neurological damage are all causes of visual impairment and the impact of these factors is discussed in relation to the resultant ophthalmic deficits. Visual acuity impairments range from blindness, due to ROP or cortical visual impairment, which can be identified at an early age, to subtle deficits related to preterm birth only identified at a later age. Visual function deficits are not limited to visual acuity but can affect contrast sensitivity, field of vision and colour vision. Strabismus and refractive errors are also very common in children following perinatal adversity. Although more is now known about the types of deficits affecting these children, there is still a poor understanding of how these deficits impact on a child's functional ability. The impact of these ophthalmic deficits on the long term ophthalmic care required, and the role of perinatal factors, is discussed.

Impact of amblyopia on vision at age 12 years: findings from a population-based study

AIMS

To report prevalence of amblyopia and long-term impact of its treatment on vision in a population-based sample of 12-year-old Australian children.

METHODS

Logarithm of minimum angle of resolution (logMAR) visual acuity (VA) was measured in 2353 children (response rate 75.3%); visual impairment was defined as VA<6/12. Amblyopia was defined using various criteria of best-corrected VA, together with an amblyogenic factor and absence of significant organic pathology. Corroborative historical data on previous diagnosis and treatment were obtained from parental questionnaires.

RESULTS

Forty-four children (1.9%) were diagnosed with amblyopia, unilateral in 40 and bilateral in four. Isolated anisometropia was the most frequent cause (41%), followed by strabismus (25%), combined anisometropia and strabismus (23%), and high ametropia (9%). Myopia, hyperopia, and astigmatism were present in 28, 51, and 44% of amblyopic children, respectively, compared to 12, 4, and 9% of non-amblyopic children. Mean best-corrected VA in amblyopic eyes was 44.5 logMAR letters (Snellen equivalent 6/9), range: 11-60 letters. Most children with amblyopia (84%) had been treated. Only 27% were visually impaired in their amblyopic eye.

CONCLUSIONS

This report documents a low amblyopia prevalence in a population of 12-year-old Australian children. Amblyopic visual impairment was infrequent in this sample despite absence of mandatory vision screening.

[Amblyopia screening]

<zakljucak> S obzirom na neujednacenu pokrivenost zemlje oftamoloskom sluzbom, resurse i edukaciju trebalo bi usmeriti, pre svega, na pedijatre i lekare opste medicine koji su ukljuceni u pregled ociju dece. Takodje, bila bi potrebna standardizacija optotipa i protokola ispitivanja. Trebalo bi poboljsati i informisanost roditelja putem stampanog materijala koji bi trebalo da bude dostupan, kako u primarnoj tako i u sekundarnoj i tercijarnoj zdravstvenoj zastiti.

Visual dysfunctions and ocular disorders in children with developmental delay. II. Aspects of refractive errors, strabismus and contrast sensitivity

PURPOSE

To evaluate the prevalence of refractive errors, strabismus and reduced contrast sensitivity in an unselected group of children with developmental delay (DD), and to propose extensions to the existing guidelines to assess the number of examinations required to optimally support children with DD.

METHODS

A total of 923 children with IQ < or = 80, aged 4-15 years, from Copenhagen County, Denmark, were ophthalmically examined. The prevalence of refractive errors and strabismus and the presence of reduced contrast sensitivity were recorded and related to level of IQ.

RESULTS

Among the 923 children, the following prevalences were found: significant hyperopia (> or = + 3 D) 15.3%; myopia (< - 0.5 D) 10.8%, and astigmatism (< - 1 cyl D) 20.6%. Strabismus was found in 26.8% of subjects (esotropia in 14.9%, exotropia in 10.3%, and other forms, including mixed types, in 1.6%). Refractive errors and strabismus were significantly correlated with low IQ. Reduced contrast sensitivity was correlated with age, visual acuity and level of IQ.

CONCLUSIONS

To our knowledge, this study is the largest on ocular disorders in children with DD. Hyperopia, astigmatism, anisometropia, strabismus and contrast sensitivity had a high prevalence, and all disorders were related to low IQ. According to the extended guidelines, an annual minimum of 565 examinations per 100 000 children (0-17 years) is required to optimally support children with DD.

Screening amblyopia of preschool children with uncorrected vision and stereopsis tests in Eastern Taiwan

AIMS OR PURPOSE: Screening for amblyopia at earliest age is important for early treatment and better prognosis. This study aimed at evaluating the validity of uncorrected distant and near visual acuity and random dot stereopsis for screening amblyopia. METHODS; In Eastern Taiwan, population-based screen tests were performed for children at age from 3 to 6 years. The tests included uncorrected distant and near visions and random dot stereopsis (300 s) test. The screen performers were registered nurses of local public health service posts. The golden standards of the tests were the results of examination by the ophthalmologists.

RESULTS

Including Hans and aboriginal Taiwanese, 5232 children were included. Screened by distance visual acuity with different cutoffs and near visual acuity, 10.3, 30.3 and 8.2% children were abnormal. Screened by random dot, only 2% children were abnormal. By a senior ophthalmologist, 115 amblyopic children were diagnosed amblyopic. The sensitivities of distance visual acuity with low/high cutoff and near visual acuity were 74.7/84.8 and 49.4%, whereas that of the NTU random dot stereogram was 20.5%. Simultaneous testing of either two of the three tests improved the sensitivity.

CONCLUSION

Screening for amblyopia by the local nurses using the visual acuity tests or random dot stereopsis test alone does not display a high sensitivity. Simultaneous testing of distant visual acuity and stereopsis test elevate the sensitivity and preserve the specificity.

Long term functional and structural outcomes of laser therapy for retinopathy of prematurity

AIMS

To assess the long term functional and structural outcomes of premature babies who received diode laser photocoagulation for threshold retinopathy of prematurity (ROP).

METHODS

25 patients (43 eyes) treated with laser were recalled for assessment at a mean follow up of 11 years. A further seven patients (14 eyes) with subthreshold ROP, which had regressed spontaneously without laser treatment, were also examined. All children underwent distance acuity, near acuity, contrast sensitivity (CS), and colour vision assessments followed by a dilated fundal examination and cycloplegic autorefraction.

RESULTS

The laser treated eyes had a mean distance visual acuity of 0.37 logMAR, a mean near visual acuity of 0.39 logMAR, a mean contrast sensitivity of 1.49 log CS units, and a mean spherical equivalent of -2.10D. An unfavourable distance visual acuity outcome occurred in five eyes (13.5%). An unfavourable near visual acuity outcome was also noted in the five eyes (13.5%) with poor distance visual outcome. 7% had an unfavourable structural outcome. On comparison with the control group, there was no significant difference in near acuity, CS, refraction, or colour vision between the two groups. However, there was a statistically significant difference in terms of distance visual acuity (p = 0.03).

CONCLUSIONS

Laser treated eyes with favourable structural outcome have a good visual outcome. The results show a long term benefit from diode laser photocoagulation in preserving distance and near vision in eyes with threshold ROP.