Significant Refractive Error Research Articles

Visual and binocular status in elementary school children with a reading problem

PurposeThis descriptive study provides a summary of the binocular anomalies seen in elementary school children identified with reading problems. MethodsA retrospective chart review of all children identified with reading problems and seen by the University of Waterloo, Optometry Clinic, from September 2012 to June 2013. ResultsFiles of 121 children (mean age 8.6 years, range 6–14 years) were reviewed. No significant refractive error was found in 81% of children. Five and 8 children were identified as strabismic at distance and near respectively. Phoria test revealed 90% and 65% of patients had normal distance and near phoria. Near point of convergencia (NPC) was <5cm in 68% of children, and 77% had stereoacuity of ≤40seconds of arc. More than 50% of the children had normal fusional vergence ranges except for near positive fusional vergencce (base out) break (46%). Tests for accommodation showed 91% of children were normal for binocular facility, and approximately 70% of children had an expected accuracy of accommodation. ConclusionFindings indicate that some children with an identified reading problem also present with abnormal binocular test results compared to published normal values. Further investigation should be performed to investigate the relationship between binocular vision function and reading performance.

Esotropia and Exotropia Preferred Practice Pattern®

Esotropia and Exotropia Preferred Practice Pattern®

The clinical presentation of bradyopsia in children

Diagnosing bradyopsia can be challenging in young children because structural ophthalmic examination is typically normal and visual acuity can improve with pinhole despite no significant refractive error. This case series highlights the clinical presentations and features of 5 affected children (3 Arab families) who harbored the same homozygous RGS9 frameshift mutation, which seems to represent a founder effect for the Arabian Peninsula.

Prevalence of amblyopia and its association with refraction in Chinese preschool children aged 36–48 months

PurposeTo determine the prevalence of amblyopia and its association with refraction in Chinese preschool children.MethodsThe Yuhuatai Pediatric Eye Disease Study, a cross-sectional, population-based study, was conducted in children aged 36–48...

Effect of simulated refractive error on adult visual acuity for paediatric tests.

Although vanishing optotype preferential-looking tasks are commonly used to measure visual acuity (VA), the relative sensitivity of these tests to refractive error is not well understood. To address this issue, we determined the effect of spherical and astigmatic simulated refractive errors on adult VA measures obtained using vanishing optotypes, picture optotypes and Sloan letters. VA was determined uniocularly for adults under conditions of spherical (0.0-3.0 DS; n=23) and astigmatic (0.0-3.0 DC at 90° and 180°; n=20) defocus using the Cardiff Acuity Test (vanishing optotypes), crowded linear Lea Symbols (picture-optotype recognition task) and the Early Treatment of Diabetic Retinopathy Study (ETDRS) letter chart. The Cardiff Acuity Test over-estimated VA compared with the Lea Symbols and ETDRS charts in both focused and defocused conditions. The mean difference between the Cardiff Acuity Test and the ETDRS chart was 0.31 logMAR (95% limits of agreement (LOA) 0.10-0.52 logMAR) in focused conditions and 0.64 logMAR (95% LOA 0.25-1.05 logMAR) with 3D of spherical defocus. Defocus degraded VA on all charts, however there was a significant chart-by-defocus interaction whereby the Cardiff Acuity Test was more resistant to the effects of both spherical (P<0.0001) and cylindrical (P<0.001) optical defocus than the recognition acuity tasks at all defocus levels. Although the Cardiff Acuity Test provides an easy method for VA measurement in infants and toddlers, there is a considerable overestimation of VA compared with recognition acuity tasks particularly in the presence of defocus. A simple correction factor (of for example three lines overestimate) cannot be applied to Cardiff acuity measures as there is increasing over-estimation of VA with increasing defocus. Infants with significant refractive error may fall within normal visual acuity ranges for the Cardiff Acuity Test.

Interrater and Test-Retest Reliability of the Beery Visual-Motor Integration in Schoolchildren.

To assess interrater and test-retest reliability of the 6th Edition Beery-Buktenica Developmental Test of Visual-Motor Integration (VMI) and test-retest reliability of the VMI Visual Perception Supplemental Test (VMIp) in school-age children. Subjects were 163 Native American third- to eighth-grade students with no significant refractive error (astigmatism <1.00 D, myopia <0.75 D, hyperopia <2.50 D, anisometropia <1.50 D) or ocular abnormalities. The VMI and VMIp were administered twice, on separate days. All VMI tests were scored by two trained scorers, and a subset of 50 tests was also scored by an experienced scorer. Scorers strictly applied objective scoring criteria. Analyses included interrater and test-retest assessments of bias, 95% limits of agreement, and intraclass correlation analysis. Trained scorers had no significant scoring bias compared with the experienced scorer. One of the two trained scorers tended to provide higher scores than the other (mean difference in standardized scores = 1.54). Interrater correlations were strong (0.75 to 0.88). VMI and VMIp test-retest comparisons indicated no significant bias (subjects did not tend to score better on retest). Test-retest correlations were moderate (0.54 to 0.58). The 95% limits of agreement for the VMI were -24.14 to 24.67 (scorer 1) and -26.06 to 26.58 (scorer 2), and the 95% limits of agreement for the VMIp were -27.11 to 27.34. The 95% limit of agreement for test-retest differences will be useful for determining if the VMI and VMIp have sufficient sensitivity for detecting change with treatment in both clinical and research settings. Further research on test-retest reliability reporting 95% limits of agreement for children across different age ranges is recommended, particularly if the test is to be used to detect changes due to intervention or treatment.

Visual status and prevalence of eye disorders among school-age children in southern Nigeria

Aim: This study assessed the types and prevalence of eye problems among school-age children in Cross River State (CRS), Nigeria.Method: The study design was a cross-sectional analytic survey of 2418 school children aged 6–17 years from seven public and three private schools in CRS, selected using the multistage random sampling technique. Ethical approval was obtained from the Ethical Committee, CRS Ministry of Health, Nigeria. The following tests were carried out on all children enrolled in the study: researcher-administered semi-structured questionnaires, LogMAR visual acuity measurements, external and internal eye examinations, non-cycloplegic auto-refractions, retinoscopy and subjective refractions. Quality assurance was carried out to validate the data collected, and data were analysed using SPSS and EPI info.Results: A total of 2418 school children were enumerated, and 2110 (87.3%) were examined; 1117 (52.9%) were girls, and 1250 (59.2%) were 6–11 years old, while 860 (40.8%) were 12–17 years old, and 77% attended public schools. The majority, 1895 (89.9%) of the children examined, had never had an eye examination. The prevalence of eye diseases among the school children was 32.1%, and the major causes were conjunctivitis 397 (18.8%; confidence interval [CI] 19.2–13.0), refractive error 243 (11.5%; CI 10.2–13.0), glaucoma suspects 52 (2.5%; CI 1.9–3.2), amblyopia 7 (0.3%; CI 0.0–0.7) and corneal opacity 4 (0.2%; CI 0.1–0.5). Analysis using chi-square tests and logistic regression shows a positive higher association of refractive error in private (16.7%) than public schools (9.9%) (crude odds ratio [COR] 1.8150; adjusted odds ratio [AOR] 1.9129, p &lt; 0.001), higher socio-economic status of parents (COR 2.3402, AOR 1.9819, p &lt; 0.001), older age group (COR 1.7258, AOR 1.8202, p &lt; 0.001) and girls (13.1%) versus boys (9.8%) (COR 0.7200, AOR 0.7144, p &lt; 0.001).Conclusion: Physical and eye health examination of children before school entry is strongly recommended. The application of 2 D lens for children who fail a standard visual acuity test should be routine during vision screening to ensure that significant refractive errors are not missed.

Is there an association between convergence insufficiency and refractive errors?

Background: Refractive errors and convergence insufficiency play major roles in reading efficiency. Uncorrected refractive errors are a primary cause of binocular anomalies, including convergence insufficiency. Symptoms of asthenopia in both refractive and binocular vision anomalies are similar. Despite the relationships that exist between them, the extent of association between refractive errors and convergence insufficiency has not been studied extensively.Aim: The aim of this study was to determine the prevalence of convergence insufficiency and refractive errors and investigate their associations with gender and age in a sample of high school children.Methods: The study design was cross-sectional and comprised data from 1056 African high school students aged 13–18 years, who were randomly selected from 13 high schools in uMhlathuze municipality in the province of KwaZulu-Natal, South Africa. In the final sample, 403 (38%) were males and 653 (62%) were females. The participants’ mean age and standard deviation were 15.89 ± 1.58 years and median age was 16 years. Refractive errors, heterophoria, near point of convergence, fusional vergences and accommodative functions were evaluated.Results: Prevalences for convergence insufficiency were as follows: low suspect 12.4% (confidence interval, [CI] 10.2–14.4), high suspect 6.3% (CI, 5.0–7.9), definite 4.6% (CI, 3.4–5.9), and pseudo-convergence insufficiency 2.1% (CI, 1.2–3.0). Refractive errors were: hyperopia 6.8% (CI, 5.3–8.4), myopia 6.0% (CI, 4.6–7.5), astigmatism 2.3% (CI, 1.8–3.2), anisometropia 1.3% (CI, 0.7–2.0) and emmetropia 86.2% (CI, 85.1–89.1). There were no significant associations between convergence insufficiency and gender (p = 0.32), age (p = 0.38), grade levels (p = 0.99) or refractive errors (p = 0.08).Conclusion: The prevalence of clinically significant convergence insufficiency and refractive errors was low in this sample of black high school students in South Africa, and there was no significant correlation between them.

A comparison of cycloplegic autorefraction and retinoscopy in Indian children

BackgroundCorrection of significant refractive errors in childhood helps in preventing amblyopia and strabismus. India has a huge demand for eye‐care services related to uncorrected refractive errors with limited manpower resources. This can be overcome by autorefractors, which are free of operator bias, do not need skilled eye‐care professionals and can be operated with ease. Hence, the purpose of this study, the first in the Indian population, was to determine the accuracy of autorefraction compared to traditional retinoscopy under cycloplegia.MethodA cross‐sectional study of all children meeting our inclusion criteria was conducted from July till October 2011 in a tertiary eye care centre. Children underwent cycloplegic (cyclopentolate plus tropicamide) refraction with an auto‐refractometer (Topcon KR‐8900) and traditional retinoscopy and the results were compared. Patients were divided into three groups: Group 1: Myopia and myopic astigmatism, Group 2: Hyperopia and hyperopic astigmatism and Group 3: Mixed astigmatism. Clinically significant difference was defined as either of more than 0.50 D difference in sphere, more than 0.5 D difference in cylinder or more than 20 degrees difference in axis.ResultsThe left eyes of 294 children (148 male) were included in the study. Mean age was 8.22 ± 3.47 years. Clinically significant differences were noted in 13.22 per cent of eyes in Group 1, 15.09 per cent of eyes in Group 2 and 20.90 per cent of eyes in Group 3. Clinically significant differences were more common in children aged less than six years (25 per cent) compared to older children (9.19 per cent). Comparing the sphere, cylinder, spherical equivalent and length of power vector values gained by autorefraction and retinoscopy, no statistically significant differences were found in any group.ConclusionAutorefraction with Topcon KR‐8900 can be used reliably in Indian children older than six years, if conducted under cycloplegia. In mixed astigmatism and children less than six years, it should be corroborated with retinoscopy.

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.

Behavior disorders in children with significant refractive errors

PurposeTo evaluate the frequency of behavioral disorders in children with significant refractive error and to compare the results with those of emmetropic children. MethodsIn this prospective, comparative study from January to September 2013, refractive errors of all 5–12-year-old children who referred to a general eye clinic were recorded. A validated Persian version of the Rutter A scale was filled out by the parents for the evaluation of the child's behavioral disorders. The Rutter A scale scores of children with significant refractive error were compared with those of emmetropic eyes. Student t test, Chi square test, and Fisher's exact test were used for analysis. Differences with a P value less than 0.05 were considered significant. ResultsOne hundred eighty-three patients, including 101 patients with significant refractive error and 82 emmetropic subjects, were studied. Overall, 44 patients (24%) had behavioral disorders, according to the Rutter A scale scores. Thirty patients (29.7%) with significant refractive error and 14 emmetropic subjects (16.9%) had behavioral disorders (P = 0.043). The prevalence of behavioral disorders were 37.5% in hyperopia, 35.7% in hyperopia-astigmatism, 21.4% in simple astigmatism, 16.7% in myopia-astigmatism, and 14.3% in myopia. Compared with emmetropic subjects, the prevalence of behavioral disorders was statistically significantly higher only in patients with hyperopia and hyperopia-astigmatism (P = 0.019 and P = 0.040). ConclusionThe prevalence of behavioral disorders is higher in children with hyperopia and hyperopia-astigmatism.

Visual and ocular effects from the use of flat-panel displays.

To evaluate the prevalence of eye symptoms in a non-presbyopic population of video display unit (VDU) users with flat-panel displays. One hundred and sixteen VDU users with flat-panel display from an urban population participated in the study; their ages ranging from 20 to 34y. There were 60 females and 56 males. An eye examination to rule out the presence of significant uncorrected refractive errors, general binocular dysfunctions and eye conditions was carried out. In order to determine and quantify the type and nature of eye symptoms, participants were asked to answer written questionnaire and the results were grouped by gender, age and number of hours a day spent using a VDU. Seventy-two percent of participants reported eye symptoms related to VDU use. Eye symptoms from moderate-to-severe were found in 23% of participants. The main symptom was moderate-to-severe tired eyes (14%); followed by sensitivity to bright lights (12%), blurred vision at far distances (10%), eyestrain or dry eye or irritated or burning eyes (9%), difficulty in refocusing from one distance to another or headache (8%) and blurred vision at near or intermediate distances (<4%). Eye symptoms were greater among females (P=0.005) and increased with VDU use, markedly above 6h spent using a VDU in a typical day (P=0.01). Significant eye symptoms relate to VDU use often occur and should not be underestimated. The increasing use of electronic devices with flat-panel display should prompt users to take appropriate measures to prevent or to relieve the eye symptoms arising from their use.

The Relationship Between Breastfeeding and Measurements of Refraction and Visual Acuity in Primary School Children.

Nutrition has been implicated in the development of some refractive errors. This study aims to investigate the relationship between refractive errors, visual acuity (VA), and Breastfeeding. In this cross-sectional study, cluster sampling was used to select 400 children aged 1-5. Fieldwork for the main study took place from September 2005 to May 2006 in two public schools of Sabzevar, Iran. Breastfeeding was defined as 6 months or more feeding. A significant refractive error was defined as at least -0.50 diopters (D) for myopia, +0.50D for hyperopia, and -0.50D for astigmatism. In addition, refractive error was calculated by converting it to spherical equivalent (SE). Statistical analysis used includes Descriptive statistics; Spearman correlation coefficients; one-way ANOVA; independent sample t-test; and Pearson chi-square test. Finally, 367 children were selected: 156 boys (42.5%) and 211 girls (57.5%). Three hundred eleven subjects (85%) had Breastfeeding. According to SE in right eye, 25.5% and 5.2% of the subjects were hyperopic and myopic, respectively, in the breastfed group, compared to 26.8% and 5.4% in the non-Breastfeeding group. In addition, hyperopia and myopia were less observable in breastfeeders than the other group for left eye. Mean VA and refractive error were different according to feeding type, but this study did not show statistically significant differences between the two groups; however, for exact judgment about these findings, more studies are suggested with a larger sample size. In conclusions based on the results, there was no significant relationship between kind of feeding during the first 6 months of infancy and VA and refractive errors.

Binocular Vision and the Stroop Test.

Recent studies report a link between optometric results, learning disabilities, and problems in reading. This study examines the correlations between optometric tests of binocular vision, namely, of vergence and accommodation, reading speed, and cognitive executive functions as measured by the Stroop test. Fifty-one students (mean age, 20.43 ± 1.25 years) were given a complete eye examination. They then performed the reading test L'Alouette and the Stroop interference test at their usual reading distance. Criteria for selection were the absence of significant refractive uncorrected error, strabismus, amblyopia, color vision defects, and other neurologic findings. The results show a correlation between positive fusional vergences (PFVs) at near distance and the interference effect (IE) in the Stroop test: the higher the PFV value is, the less the IE. Furthermore, the subgroup of 11 students presenting convergence insufficiency, according to Scheiman and Wick criteria (2002), showed a significantly higher IE during the Stroop test than the other students (N = 18) who had normal binocular vision without symptoms at near. Importantly, there is no correlation between reading speed and PFV either for the entire sample or for the subgroups. These results suggest for the first time a link between convergence capacity and the interference score in the Stroop test. Such a link is attributable to the fact that vergence control and cognitive functions mobilize the same cortical areas, for example, parietofrontal areas. The results are in favor of our hypothesis that vergence is a vector of attentional and cognitive functions.

Ophthalmic Manifestations in Children With Congenital Hypothyroidism.

To evaluate the frequencies of ophthalmic abnormalities in children with congenital hypothyroidism. A total of 121 patients with a history of congenital hypothyroidism, aged 1 to 216 months, were included in the study. The initial ophthalmological examinations and demographic data of patients who were examined between April 2013 and April 2015 were retrospectively reviewed. Accompanying systemic abnormalities were also noted. Ophthalmic pathology was determined in 40.4% (49 of 121) of patients with congenital hypothyroidism, of which 79.5% (39 of 49) had significant refractive errors and 32.6% (16 of 49) had strabismus. Systemic abnormalities were observed in 74.3% (90 of 121) of the children, among which 47.1% (57 of 121) were congenital heart defects and 38.0% (46 of 121) were neurologic abnormalities. A high prevalence of Down syndrome (17.3%; 21 of 121) and atopic dermatitis (8.2%; 10 of 121) was detected among patients with congenital hypothyroidism. In addition to many associated systemic abnormalities, ophthalmic pathologies may also occur in children with congenital hypothyroidism. Thus, routine ophthalmological examination is recommended for these children, starting from the time of initial diagnosis.

Clinical Competency of 1-Year Trained Vision Technicians in Andhra Pradesh, India

Purpose: To assess clinical competency of 1-year trained vision technicians (VTs) in detecting and referring causes of visual impairment in India.Methods: Eye examination results and management plans for 328 patients examined by 24 VTs in 24 vision centers of LV Prasad Eye Institute in Andhra Pradesh were compared with those of a standard optometrist who examined the same patients. Eye examinations included retinoscopy and subjective refraction, slit lamp examination, applanation tonometry and undilated direct ophthalmoscopy. Data were analyzed for level of concordance in retinoscopy, spectacle prescription, disease detection and referral.Results: VTs demonstrated moderate to good levels of agreement in refraction, disease detection and referral. Sensitivity and specificity for ocular pathology identification were 77.4% (95% confidence interval, CI, 69.4–84.2%) and 86.6% (95% CI 81.1–91.1%), respectively. The highest sensitivity was demonstrated in detecting significant cataract (91.5%) and refractive error (83.0%). VT spectacle prescriptions were accurate 76% of the time for mean spherical equivalent and 65% of the time for astigmatism. VT sensitivity in detecting posterior segment abnormalities was low (18.5%) resulting in failure to detect retinal conditions such as diabetic retinopathy and maculopathy. Despite lack of recognition of the specific pathology, referral decisions were correct in 78.4% of cases.Conclusion: VTs in India competently detect and manage or refer the two most common causes of visual impairment; uncorrected refractive error and cataract. Over two-thirds of patients received accurate and appropriate services from VTs, suggesting that they are a useful and competent cadre for rural and remote eye care.

The Prevalence of Uncorrected Refractive Errors in Adolescents Incarcerated in a Youth Detention Center

The purpose of this study was to determine the number of residents requiring corrective lenses in a youth detention center for juveniles from 12 to 18 years old over a 2-year period. A greater number of adolescents incarcerated for criminal activity in a detention center had uncorrected refractive errors (34.87 %) as compared to a comparable population in the public school system (22 %). The prevalence of significant refractive errors among incarcerated adolescents in this study is significantly higher than has been reported previously. The current study found a refractive error rate of almost 35 %. This difference can be explained by a number of factors in their social environments and identifies an area for potential intervention to reduce antisocial behavior in this population.

Association of refractive error with optic nerve hypoplasia.

To evaluate the association of refractive error with optic nerve hypoplasia (ONH). A total of 30 ONH subjects were recruited and underwent comprehensive eye exams. Refractive error data from this group was compared to data from a group of 3232 non-ONH subjects from the same facility. Spherical equivalent was calculated to assess refractive error. Multiple logistic regression was used to evaluate the relationship between ONH and refractive error while controlling for age, race, and gender. The prevalence of hyperopia (≥+1.00 D), myopia (<-0.75 D), and anisometropia (≥1.00 D) was higher in ONH subjects than in controls. ONH subjects were 9.1 times more likely to be hyperopic than emmetropic (OR = 9.1, 95% CI = 2.9-28.4, p < 0.001) and 3.8 times more likely to be myopic than emmetropic (OR = 3.8, 95% CI = 1.2-11.5, p = 0.02). Unilateral ONH subjects were 10.0 times more likely to have anisometropia than controls (OR = 10.0, 95% CI = 3.9-25.6, p < 0.0001). Bilateral ONH subjects were 3.8 times more likely to have anisometropia than controls (OR = 3.8, 95% CI = 1.1-12.7, p = 0.03). Optic nerve hypoplasia subjects were more likely than control subjects to exhibit significant refractive errors, particularly hyperopia. Anisometropia tended to be more likely to occur in subjects with unilateral ONH than in bilateral ONH. Based on our findings, we recommend that clinicians perform a comprehensive eye examination on all patients with ONH and prescribe for existing refractive error when visual acuity or general visual function can realistically be improved.

“It does matter”: outcomes of prescribing glasses in students with neuro-developmental disabilities

The purpose of this study is to determine if students with neurodevelopmental disorders and significant refractive errors, can demonstrate behavioral and communication improvements by adapting to wearing glasses.

Burden of ocular and visual disorders among pupils in special schools in Nepal

ObjectivesTo determine detailed oculo-visual characteristics of children with intellectual disability studying in special schools and explore the burden of visual impairment.Design of the studyDetailed ophthalmic examination was carried out in...