Non-cycloplegic Refraction Research Articles

Light Intensity in Nursery Schools: A Possible Factor in Refractive Development.

Increased levels of outdoor light have been found to be associated causally with decreased rates of myopia. The goal of this study was to measure the effect of indoor nursery school light intensity on refraction of preschool children in Israel. A total of 1596 children aged 4 to 5 years from 27 nursery schools were examined. Light intensity was tested with a luxmeter device (Lux) inside and outside the nursery school. Noncycloplegic refractions were measured with the PlusOptix vision A09 screening device. Data analysis was performed using Pearson coefficients, chi-square tests for proportions and ANOVA tests by tertiles of illuminance. This study included 1131 kindergarten children with a mean age of 4.87 ± 0.33 years, of which 571 were female (50.5%). The mean light intensity of the low, medium, and high intensity groups differed significantly (ANOVA P < 0.001) at 359 ± 2.64 lux (range 264-431), 490 ± 2.21 lux (range 432-574), and 670.76 ± 3.73 lux (range 578-804), respectively. Mean spherical equivalent (SE) was +0.56 ± 0.03D for the low-intensity group, +0.73 ± 0.03D for the medium-intensity group, and +0.89 ± 0.03D for the high-intensity group (ANOVA P < 0.001). The low-intensity group had 42.1% of children with zero refraction or less, while the high-intensity group had 19.3%. In the nursery schools, lower amounts of illumination were associated with less hyperopic refractive error. As the low hyperopic reserve is a risk factor for developing myopia, this finding needs to be followed up to establish whether this association reflects a causal relationship, which could be modulated for the prevention of myopia.

Risk Factors for Myopia in 2 Hong Kong School Systems: A Pilot Study.

Myopia has reached "epidemic" proportions, especially in several East Asian countries. Most myopia emerges during childhood, particularly during the school years. The aim of this study was to investigate myopia prevalence and compare risk factors of myopia among Hong Kong Chinese primary school children under 2 different educational systems. Cross-sectional study. Visual assessments were conducted in 1 government-funded primary school (n = 159) and 1 international school (n = 223) in Hong Kong in September and October 2018, respectively. Measurements were performed on children aged 8 to 10 years old. Noncycloplegic refraction and axial length were measured, respectively. A validated questionnaire focusing on demographic information, nonscreen time (eg, reading and writing on paper materials), screen time (ie, smartphones and tablets usage), time spent on outdoor activities, and other myopia risk factors was completed by parents of participants. The prevalence of myopia [37.5% vs 12.8%, P < 0.001; spherical equivalent refraction (SER) ≤ -1.00 diopter (D)] and refractive astigmatism [25.0% vs 7.2%, P < 0.001; cylinder (Cyl) ≥ 1.00 diopter cylinder (DC)] were significantly higher in the local school than in the international school. Students in the local school were slightly older than those attending the international school (9.17 ± 0.82 years vs 8.95 ± 0.85 years, P = 0.046), and there was no significant difference in gender distribution between the 2 schools (P = 0.51). There were significant differences in the demographic information including parental myopia (P < 0.001), family income (P < 0.001), and parents' educational level (P < 0.001) between the 2 schools. Multiple regression analysis showed that parental myopia history and continuous near work was associated with myopia in the local school, while the father's educational level was related to myopia in the international school. In this pilot study, despite the much higher prevalence of parental myopia and high myopia in the international school, the myopia prevalence among the students is lower in this school than in the local school, suggesting that environmental factors other than genetics might have a stronger protective effect in this school population.

Prevalence of pathological myopia in Upper Egypt

Background and aim Pathological myopia (PM) is one of the main causes of blindness globally, and its prevalence continues to increase rapidly over time. The aim of this study was to investigate the prevalence of PM in the clinical population in Assiut City, Upper Egypt, during a period of 1 year. Patients and methods This cross-sectional study was carried out on a clinical population attending a large ophthalmology center in Assiut City, Upper Egypt, during the period from January to December 2018. All patients were subjected to full ophthalmologic examination. The noncycloplegic refraction was measured using an autorefractometer. The examined eyes were diagnosed as PM if they had refraction of more than or equal to −6 D spherical equivalent or an axial length of more than or equal to 25.5 mm. Results The study included 1548 eyes of 812 patients. Pathologically myopic eyes represented 152 eyes, with a prevalence of 9.82%. Of the total included patients, 102 (12.6%) patients had at least one pathologically myopic eye. Patients with bilateral PM represented 73 (71.6%) cases. Their refractive error ranged from −6.0 to −26.0 D, with a mean of −13.24±4.13 D, and their mean axial length was 28.2±2.14 mm and ranged from 26.1 to 35.2 mm. Conclusion The prevalence of PM in the studied sample was 9.82%, which was obviously higher compared with studies on other populations. Further large community-based studies are warranted to determine its prevalence as a step to overcome this true burden.

Prevalence and risk factors of myopia amongst Grade 8 learners in the Vhembe district, South Africa

Background: Myopia is the most common cause of refractive errors in both adults and children in many countries. However, it is not a simple refractive error but sometimes and eyesight-threatening disorder. The disorder has a great impact on public health and the socio-economic well-being of people, particularly children.Aim: The study aimed to assess the prevalence of myopia amongst secondary school learners.Setting: The study was conducted in the Vhembe District, South Africa.Methods: A cross-sectional study was carried out amongst 297 Grade 8 students of 13 to 14 years of age. The students were selected using a multi-stage-stratified cluster sampling technique from three secondary schools. Two public secondary schools and one private secondary school. The learners’ socioeconomic background, type of school and parental myopia were assessed by a questionnaire before visual acuity assessment. Learners with visual acuity of less than or equal to 6/12 in the worse eye, who showed vision improvement with pinhole, underwent non-cycloplegic retinoscopy and subjective refraction were selected. Myopia was defined as a spherical equivalent of less than or equal to −0.50 dioptre (D). Data were analysed using descriptive statistics.Results: A total of 289 learners completed the study (156 aged 14 years and 133 aged 13 years). A total of 30 learners were identified to have myopic refractive error making the prevalence of 10.4%. Of the 154 females, 14 (47.0%) had myopia, whilst 16 (53.0%) of the 135 males had myopia making males slightly more myopic than females. From the total learners diagnosed to have refractive error (n = 40), myopia constituted 30/40 (75.0%) of the learners indicating that it is the commonest type of refractive error amongst secondary learners. Myopia was more common amongst older age children (14 years; 57.0%). About 18 (60.0%) participants were from the urban area. A total of 17 (57%) of the myopic learners attended private school and about 63% of the participants’ parents were myopic.Conclusion: Spending more time indoor and continuous reading without resting are risk factors of myopia whilst increased outdoor activities were observed as protective environmental factors against myopia in secondary school learners. Doing more outdoors activities may be beneficial to protect against myopia onset.

Prevalence of refractive errors in school-going children of Taif region of Saudi Arabia.

PURPOSE:To determine the prevalence of refractive errors in the pediatric population in Taif, Saudi Arabia.METHODS:This cross-sectional study included 7356 eyes of 3678 primary and secondary school children (males = 1837; females = 1841) with a mean age of 11.8 ± 2.2 years (range: 7–18) (males = 11.4 ± 2.0 [range: 8–16]; females = 12.2 ± 2.3 [range: 7–18]). All participants were selected from the school registers. The participants underwent noncycloplegic refraction to determine refractive errors. Students who refused visual acuity assessment or eye examination and were inconsistent in visual acuity assessment were excluded.RESULTS:The manifest refraction spherical equivalent of the study population was 0.37 ± 1.52 D (range from − 18.4 to 8.8 D) (males = −0.32 ± 1.4 D [range − 15.88–8.8 D]; females = −0.42 ± 1.6 D [range − 18.38–8.0 D]). The overall prevalence of uncorrected refractive errors among school children in this study was 50.91%. The overall distribution of astigmatism (cylinder error of ≥0.50 D) in the current study population was found to be 50.14% (3688/7356 eyes).CONCLUSION:Nearly half of the study population in this area was affected with at least one type of refractive error. The findings reveal the necessity for implementing timely and sensitive screening programs/methods to identify and correct refractive errors in this age group.

Perbedaan Hasil Pemeriksaan Tajam Penglihatan dan Refraksi pada Anak Usia 4-12 tahun pada Pemeriksaan Non Sikloplegik dan Sikloplegik

ABSTRACTBackground of Study: Globally, there are 19 million children with visual impairment, 12 million are caused by uncorrected refractive errors. Uncorrected refractive errors in children have the potential to cause amblyopia, severe visual impairment and even blindness. Refractive errors in children must receive proper management. Cycloplegic refraction is a gold standart method for children to minimize the effect of strong accommodation in childhood. The purpose of the study: to analyze the differences between the results of the visual acuity examination and refractive examination between the non-cycloplegic and the cycloplegic examination in children aged 4-12 years. Methods: This study is an analytical observational study through recording medical records of patients 4-12 y.o between November 2020-October 2021, which were carried out with non-cycloplegic and cycloplegic refraction. Data were analyzed by SPSS with WilcoxonTest. Results: There were 106 eyes of children consisting of 62(58%) boys and 44(42%) girls. Based on statistical tests, there was no difference in natural visual acuity on non-cycloplegic and cycloplegic examinations. There were differences between non-cycloplegic and cycloplegic refractions. The difference in refraction results towards the positive spherical 75(70,75%) children towards the negative spherical 21(19.81%) children, only 10(9,4%) children showed the same results between the two refractive stages. Conclusion: There was no difference in children's visual acuity between the non-cycloplegic examination and the cycloplegic examination, but there were differences in the results of non-cycloplegic and cycloplegic refraction in children aged 4-12 years. Therefore, the determination of the size of the glasses in children must be done through cycloplegic refraction.Keywords : Refraction, Cycloplegic Refraction, Visual Acquity, Children

Relationship between visual and neurodevelopmental measures at 2 years with visual acuity and stereopsis at 4.5 years in children born at risk of neonatal hypoglycaemia.

Mild to moderate vision loss affects many children and can negatively impact a child's early literacy and academic achievement. Nevertheless, there is no consensus on which factors present in early childhood indicate the need for long-term ophthalmic follow up, particularly in children with a history of perinatal adversity. This study identified the relationship between visual, cognitive, motor and demographic factors at 2years of age and visual acuity (VA) and stereoacuity at 4.5years of age. Five hundred sixteen children identified as being at risk of neonatal hypoglycaemia were recruited soon after birth. At 2years of age, binocular VA, stereoacuity and non-cycloplegic refraction were measured and a clinical neuro-developmental assessment with the Bayley Scales of Infant Development III (BSID-III) was conducted by a trained examiner. Monocular VA and stereoacuity were measured at 4.5years of age. Three hundred twenty-eight children completed both the 2 and 4.5year vision and neurodevelopmental assessments. Multiple linear regression showed oblique astigmatism and motor function at 2years were significantly associated with VA at 4.5years of age, while spherical equivalent refraction, motor scores and stereoacuity at 2years were significantly associated with stereoacuity at 4.5years of age. BSID-III motor scores had the best sensitivity (81.8%) and specificity (51.5%) for identifying impaired stereoacuity at 4.5years. However, all measures at 2 years were poorly associated with VA at 4.5years old. Vision and neurodevelopmental measures at 2years were poorly associated with visual function at 4.5years of age. However, lower scores on tests of motor function at 2years may be associated with vision abnormalities, particularly reduced stereopsis, at 4.5years of age and referral for comprehensive vision assessment for these children may be warranted.

Birth weight and refractive state measured by Spot Vision Screener in children aged 40 months

ObjectivesChildren with retinopathy of prematurity (ROP) often have myopia. Even without ROP, birth weight and refractive state are related immediately after birth, but this relationship is reduced with increasing age....

Prevalence and risk factors for myopia and high myopia: A cross-sectional study among Han and Uyghur students in Xinjiang, China.

This study aimed to investigate the prevalence and risk factors for myopia and high myopia among Han and Uyghur students in Xinjiang, China. This cross-sectional study with a multistage, stratified cluster sampling method was completed in Xinjiang, China. Visual acuity and noncycloplegic refraction were measured. The crude and sex- and age-adjusted prevalence of myopia and high myopia in Han and Uyghur students were compared. Multivariate logistic regression analyses were applied to identify risk factors associated with myopia and high myopia. In total, 84,033 participants were included in the final analysis, comprising 64,110 Han and 19,923 Uyghur participants. The overall age- and sex-adjusted prevalence of myopia and high myopia were 47.70% (95% CI: 47.67-47.74) and 2.55% (95% CI: 2.54-2.56), respectively. Compared to the Uyghur population, the Han population had a higher prevalence of myopia (63.59% vs. 21.34%, p<0.0001) and high myopia (4.68% vs. 0.6%, p<0.0001). Han ethnicity, age, female sex, higher education level and living in urban areas were found to be positively associated with myopia and high myopia. Living in northern Xinjiang was found to be positively associated with myopia but negatively associated with high myopia. Our study investigated the prevalence of myopia and high myopia among Han and Uyghur students aged 4-23years in Xinjiang, China. The Han population had a higher prevalence of myopia and high myopia than the Uyghur population. However, the prevalence of myopia among the Uyghur population showed a more remarkable increasing trend than that among the Han population in Xinjiang.

The Prevalence of Visual Impairment and Refractive Errors among a Youth Population in Mozambique: Evidence of the Need for Intervention.

Visual impairment (VI) can significantly interfere in the child’s daily activities and quality of life, having a negative effect on their development and learning. The aim of the study was to determine the prevalence of VI and associated demographic factors in students examined during the program “Moçambique te vejo melhor”. This study was cross-sectional and retrospective, based on the 2018/19 edition of the program. Eye examinations were performed in secondary school students, aged between 12 and 20 years, of five districts in Nampula province. The examination included visual acuity, non-cycloplegic refraction and assessment of the anterior and posterior segment and ocular adnexa. The prevalence of uncorrected, presenting and best-corrected VI found was 18.3%, 10.8%, and 5.0%, respectively. Refractive error (RE) had a prevalence of 24.7%, and the age groups between 15–17 years and 18–20 years were significantly associated with myopia (with OR: 4.9 and OR: 8.8, respectively), as well as the 11th and 12th grade (OR: 8.1 and OR: 10.7, respectively), and Malema district had association with myopia (ORa: 0.4) and hyperopia (ORa: 0.4 and OR: 0.3) as a protective factor. The prevalence of RE and VI was relatively high, showing the need for greater intervention at the school level.

Visual Health and its Relationship with Screen Time among School Children: A Cross-Sectional Study in Sarawak, Malaysia

&lt;p class="0abstract"&gt;&lt;strong&gt;Objective: &lt;/strong&gt;This study intended to determine visual health of the school children and investigate its relationship with screen time. &lt;strong&gt;Methods: &lt;/strong&gt;This was a school-based cross-sectional study using multistage cluster sampling. A self-reported and interviewer-administered questionnaire were used to compile screen time information. Children presenting visual acuity was evaluated with Snellen chart and non-cycloplegic refraction was performed to those acuities worse than 6/12. Data analysis was performed using SPSS version 22. A p-value ≤0.05 with 95% CI was considered as statistically significant. &lt;strong&gt;Results: &lt;/strong&gt;About 87% children had normal or near normal visual acuity and 13% had visual impairment. The prevalence of refractive error was 22.8%. Astigmatism was the most prevailing type of refractive error, 10%. The children spent on average of 13.82 hours per week on screen time. Television is the most popular electronic devices. Boy spent more time on gaming consoles than girl. There was no statistically significant relationship between refractive error and screen time (p=0.581). &lt;strong&gt;Conclusion: &lt;/strong&gt;The prevalence of refractive error among school children was 23%. The children spent nearly 14 hours per week on screen time. There was no statistically significant relationship between refractive error and screen time. Periodical children vision screening is paramount for early detection of vision impairment and provide possible intervention.&lt;/p&gt;

Ophthalmic Injuries After the Port of Beirut Blast—One of Largest Nonnuclear Explosions in History

A review of the injury patterns, treatment strategies, and responding physicians' experience during the Port of Beirut blast may help guide future ophthalmic disaster response plans. To present the ophthalmic injuries and difficulties encountered as a result of the Port of Beirut blast on August 4, 2020. A retrospective medical record review of all patients who presented to the emergency department and 13 ophthalmology outpatient clinics at the American University of Beirut Medical Center for treatment of ophthalmic injuries sustained from the explosion in Port of Beirut, Beirut, Lebanon, from August 4 to the end of November 2020. Patients were identified from emergency records, outpatient records, and operative reports. Types of ocular injuries, final best-corrected visual acuity, and need for surgical intervention were evaluated. Visual acuity was measured with correction based on noncycloplegic refraction using the Snellen medical record. Ocular or ocular adnexal injuries sustained from the Port of Beirut explosion. A total of 39 blast survivors with ocular injuries were included in this study. Twenty-two patients presented with ocular injuries on the day of the blast, and 17 patients presented within the following 3 months to the ophthalmology clinics for a total of 48 eyes of 39 patients were treated secondary to the blast. Thirty-five patients (89.6%) were adults, and 24 (61.5%) were female. A total of 21 patients (53.8%) required surgical intervention, more than half of which were urgently requested on the same day of presentation (14 [35.9%]). Most eye injuries were caused by debris and shrapnel from shattered glass leading to surface injury (26 [54.2%]), eyelid lacerations (20 [41.6%]), orbital fractures (14 [29.2%]), brow lacerations (10 [20.8%]), hyphema (9 [18.8%]), open globe injuries (10 [20.8%]), and other global injuries. Only 7 injured eyes (14.5%) had a final best-corrected visual acuity of less than 20/200, including all 4 open globe injuries with primary no light perception (8.3%) requiring enucleation or evisceration. In the aftermath of the Port of Beirut explosion, a review of the ophthalmic injuries showed a predominance of shrapnel-based injuries, many of which had a delayed presentation owing to the strain placed on health care services. Reverting to basic approaches was necessary in the context of a malfunctioning electronic medical record system.

Accuracy of Noncycloplegic Refraction for Detecting Refractive Errors in School-aged African Children.

Cycloplegia is often restricted in screening settings. Previous studies have evaluated noncycloplegic refraction for screening, but their data are not fully applicable to school-aged African children. This article adds to the literature by investigating this in school-aged African children. The purpose of this study was to evaluate the ability of noncycloplegic autorefraction (NCA) and noncycloplegic retinoscopy (NCR) to detect refractive errors in school-aged African children and quantify differences between noncycloplegic and cycloplegic refraction measures. Autorefraction and retinoscopy were performed on 150 children aged 6 to 15 years before and after cyclopentolate cycloplegia. Subjective refraction was performed by the same examiner after cycloplegia. Noncycloplegic and cycloplegic measurements were compared, and the data were assessed with receiver operating characteristic curves and Bland-Altman plots. With the exception of cylindrical vector J0 (P = .17) and J45 (P = .08) obtained with NCR, all mean measures of NCA and NCR significantly differed from mean cycloplegic subjective refraction measurements by -0.71 ± 0.67 (P ≤ .001; 95% confidence interval, -2.02 to +0.60) and -0.75 ± 0.68 (P ≤ .001; 95% confidence interval, -2.08 to +0.58), respectively. Mean spherical power between the two tests did not differ (NCA -NCR, mean bias of -0.037 ± 0.675 and 95% limits of agreement of -1.36 to 1.286; P = .51). The sensitivities for detecting any refractive error for NCR and NCA were 86.8 and 82.9%, respectively, and the specificities were 82.0% for NCR and 82.4% for NCA. Performance of both tests was excellent for myopia (area under the curve, >0.90; sensitivity, ≥90%) and similar (P = .13), but the specificities for detecting hyperopia were 78.0% for NCR and 80.0% for NCA. Noncycloplegic refraction may accurately detect astigmatism and myopia in this population but may elicit higher myopic values and lower hyperopic values than using cycloplegic refraction.

Effect of Sunshine Duration on Myopia in Primary School Students from Northern and Southern China.

BackgroundTo assess the current myopia prevalence rate and evaluate the effect of sunshine duration on myopia among primary school students in the north and south of China.MethodsThis prospective cross-sectional study pooled data from 9171 primary school students (grades from 1 to 6) from four cities in the north and south of China. National Geomatics Center of China (NGCC) and China Meteorological Administration provided data about altitude, latitude, longitude, average annual temperature, and average annual sunshine duration. Non-cycloplegic refraction was recorded, and prevalence rates in primary school students and factors associated with myopia were analyzed. Univariate and multivariate logistic regression models were used to determine the independent association of risk factors of myopia.ResultsThe overall myopia prevalence was 28.0%, from 7.5% to 50.6% for first and sixth grades, respectively. Low, moderate and high myopia significantly increased with school grades from 7.30% to 35.0%, 0.3% to 13.60% and 0.00% to 1.9%, respectively. Multiple regression analysis revealed that longer average cumulative daylight hours were connected to lower myopia prevalence in primary school students (OR, 0.721; 95% CI, [0.593–0.877]; P=0.001), whereas girls and higher grade was independently associated with higher myopia prevalence (girls: β=0.189; OR, 1.208; 95% CI, [1.052–1.387]; P=0.007; higher grade: β=0.502; OR, 1.652; 95% CI, [1.580–1.726]; P<0.001).ConclusionThis study demonstrated that myopia was highly prevalent in southern Chinese cities over northern ones, linked to shorter light exposure, higher education level, and female gender. Such findings reinforced the beneficial impact of daylight exposure with a protective role against myopia development.

Choroidal and Retinal Thickness and Axial Eye Elongation in Chinese Junior Students.

PurposeTo explore the associations between macular choroidal and retinal thickness and axial elongation in non-myopic and myopic junior students.MethodsIn this school-based longitudinal observational study, axial length was measured by optical low-coherence reflectometry, and choroidal thickness and retinal thickness were measured by spectral-domain optical coherence tomography. Myopia was defined as non-cycloplegic objective spherical equivalent refraction ≤ −0.50 diopters. Structural equation modeling and multiple linear regression models were used to analyze the associations between baseline choroidal and retinal thickness with axial elongation.ResultsOut of 1307 students examined at baseline in 2017, 1197 (91.58%) returned for follow-up examination in 2018, with a median age of 12.00 years (interquartile range [IQR], 1.00) and included 667 boys (55.72%). Within a 1-year period, the median axial elongation of right eyes was 230 µm (IQR, 180) in boys and 200 µm (IQR, 160) in girls (P = 0.032). The thinner temporal choroidal thickness was associated with greater 1-year axial elongation only in myopic students (β, −0.20; 95% confidence interval [CI], −0.37, −0.03), the thinner temporal retinal thickness was associated with greater 1-year axial elongation in both non-myopic (β, −2.67; 95% CI, −4.52, −0.82) and myopic (β, −0.99; 95% CI, −1.68, −0.30) students, after adjustment for sex, age, and height. Subfoveal and nasal choroidal and retinal thickness were not significantly associated with axial elongation in either non-myopic or myopic students.ConclusionsA thinner temporal choroid at age 12 years may predict greater 1-year axial elongation in myopic students, and a thinner temporal retina may predict greater 1-year axial elongation in both non-myopic and myopic students. This finding may help to identify children at risk and control axial elongation with potential preventive strategies.

A randomized clinical trial using cyclopentolate and tropicamide to compare cycloplegic refraction in Chinese young adults with dark irises

BackgroundTo evaluate the necessity of cycloplegia for epidemiological studies of refraction in Chinese young adults (aged 17–22 years) with dark irises, and to compare the cycloplegic effects of 1% cyclopentolate and 0.5% tropicamide in them.MethodsA total of 300 young adults (108 males and 192 females) aged 17 to 22 years (mean 19.03 ± 1.01) were recruited from Tianjin Medical University from November 2019 to January 2020. Participants were randomly divided into two groups. In the cyclopentolate group, two drops of 1% cyclopentolate eye drop were administrated (one drop every 5 min), followed by autorefraction and subjective refraction 30 to 45 min later. In the tropicamide group, four drops of 1% Mydrin P (Tropicamide 0.5%, phenylephrine HCl 0.5%) eye drop were given (one drop every 5 min), followed by autorefraction and subjective refraction 20 to 30 min later. The participants and the examiners were masked to the medication. Distance visual acuity, intraocular pressure (IOP), non-cycloplegic and cycloplegic autorefraction (Topcon KR-800, Topcon Co. Tokyo, Japan), non-cycloplegic and cycloplegic subjective refraction and ocular biometry (Lenstar LS-900) were performed.ResultsThe values of spherical equivalent (SE) and sphere component were significantly different before and after cycloplegia in the cyclopentolate group and the tropicamide group (p < 0.05). The mean difference between noncycloplegic and cycloplegic autorefraction SE was 0.39 D (±0.66 D) in the cyclopentolate group and 0.39 D (±0.34 D) in the tropicamide group. There was no significant difference in the change of SE and sphere component after cycloplegia between the cyclopentolate group and the tropicamide group (p > 0.05). In each group, no significant difference was found between autorefraction and subjective refraction after cycloplegia (p > 0.05). We also found that more positive or less negative cycloplegic refraction was associated with the higher difference in SE in each group.ConclusionsCycloplegic refractions were generally more positive or less negative than non-cycloplegic refractions. It is necessary to perform cycloplegia for Chinese young adults with dark irises to obtain accurate refractive errors. We suggest that cycloplegic autorefraction using tropicamide may be considered as a reliable method for epidemiological studies of refraction in Chinese young adults with dark irises.Trial registrationThe study was registered on September 7, 2019 (Registration number: ChiCTR1900025774).

Prediction of myopia onset with refractive error measured using non-cycloplegic subjective refraction: the WEPrOM Study

Background/aimsTo evaluate the predictive performance of various predictors, including non-cycloplegic refractive error, for risk of myopia onset under pragmatic settings.MethodsThe Wenzhou Medical University Essilor Progression and Onset of Myopia Study...

Association of Myopia and Genetic Variants of TGFB2-AS1 and TGFBR1 in the TGF-β Signaling Pathway: A Longitudinal Study in Chinese School-Aged Children.

BackgroundMyopia is a complex multifactorial condition which involves several overlapping signaling pathways mediated by distinct genes. This prospective cohort study evaluated the associations of two genetic variants in the TGF-β signaling pathway with the onset and progression of myopia and ocular biometric parameters in Chinese school-aged children.MethodsA total of 556 second grade children were examined and followed up for 3.5 years. Non-cycloplegic refraction and ocular biometric parameters were measured annually. Multivariate regression analysis was used to assess the effect of the TGFBR1 rs10760673 and TGFB2-AS1 rs7550232 variants on the occurrence and progression of myopia. A 10,000 permutations test was used to correct for multiple testing. Functional annotation of single nucleotide polymorphisms (SNPs) was performed using RegulomeDB, HaploReg, and rVarBase.ResultsA total of 448 children were included in the analysis. After adjustments for gender, age, near work time and outdoor time with 10,000 permutations, the results indicated that the C allele and the AC or CC genotypes of rs7550232 adjacent to TGFB2-AS1 were associated with a significantly increased risk of the onset of myopia in two genetic models (additive: P’ = 0.022; dominant: P’ = 0.025). Additionally, the A allele and the AA or AG genotypes of rs10760673 of TGFBR1 were associated with a significant myopic shift (additive: P’ = 0.008; dominant: P’ = 0.028; recessive: P’ = 0.027). Furthermore, rs10760673 was associated with an increase in axial length (AL) (P’ = 0.013, β = 0.03) and a change in the ratio of AL to the corneal radius of curvature (AL/CRC) (P’ = 0.031, β = 0.003). Analysis using RegulomeDB, HaploReg, and rVarBase indicated that rs7550232 is likely to affect transcription factor binding, any motif, DNase footprint, and DNase peak.ConclusionThe present study indicated that rs10760673 and rs7550232 may represent susceptibility loci for the progression and onset of myopia, respectively, in school-aged children. Associations of the variants of the TGFBR1 and TGFB2-AS1 genes with myopia may be mediated by the TGF-β signaling pathway; this hypothesis requires validation in functional studies. This trial was registered as ChiCTR1900020584 at www.Chictr.org.cn.

Relationship between Myopia Progression and School Entrance Age: A 2.5-Year Longitudinal Study.

Objective To investigate the association between myopia progression and school entrance age among Chinese schoolchildren and to suggest a more appropriate school age. Methods 1,463 children aged six to nine years from Wenzhou, China, were examined and followed up for two and a half consecutive years. Their noncycloplegic refraction was measured twice each year by using an automatic refractometer; axial length (AL) and corneal radius of curvature (CRC) were tested annually by using the IOLMaster for 2.5 years. The questionnaires were completed by the children to collect detailed information regarding risk factors. Here, myopia is defined as a spherical equivalent less than −1.0D. Results The changes in spherical equivalent (SE) of 7-year-old children in grade 1 and grade 2 were −0.45D and -0.56D, while changes in AL were 0.59 mm and 0.62 mm, respectively. The SE changes of 8-year-old children in grade 2 and grade 3 were −0.54D and −0.75D; meanwhile, the AL changes were 0.57 mm and 0.61 mm, respectively. Significant statistical differences were observed in ocular biological structure parameters, except for corneal radius of curvature (CRC) or anterior chamber depth (ACD), among children with the same age in different grades during this study. The prevalence of myopia was also significantly higher in higher grades for children with same age. Conclusions Myopia is related to children's school entrance age. Children who start school in an earlier age are more likely to suffer from myopia, and the progression of myopia can be considerably faster. Therefore, it is recommended to enter school after the age of 7.

The Sankara Nethralaya Tamil Nadu Essilor Myopia (STEM) Study-Defining a Threshold for Non-Cycloplegic Myopia Prevalence in Children.

The aim of this study was to investigate the agreement between cycloplegic and non-cycloplegic autorefraction with an open-field auto refractor in a school vision screening set up, and to define a threshold for myopia that agrees with the standard cycloplegic refraction threshold. The study was conducted as part of the Sankara Nethralaya Tamil Nadu Essilor Myopia (STEM) study, which investigated the prevalence, incidence, and risk factors for myopia among children in South India. Children from two schools aged 5 to 15 years, with no ocular abnormalities and whose parents gave informed consent for cycloplegic refraction were included in the study. All the children underwent visual acuity assessment (Pocket Vision Screener, Elite school of Optometry, India), followed by non-cycloplegic and cycloplegic (1% tropicamide) open-field autorefraction (Grand Seiko, WAM-5500). A total of 387 children were included in the study, of whom 201 were boys. The mean (SD) age of the children was 12.2 (±2.1) years. Overall, the mean difference between cycloplegic and non-cycloplegic spherical equivalent (SE) open-field autorefraction measures was 0.34 D (limits of agreement (LOA), 1.06 D to −0.38 D). For myopes, the mean difference between cycloplegic and non-cycloplegic SE was 0.13 D (LOA, 0.63D to −0.36D). The prevalence of myopia was 12% (95% CI, 8% to 15%) using the threshold of cycloplegic SE ≤ −0.50 D, and was 14% (95% CI, 11% to 17%) with SE ≤ −0.50 D using non-cycloplegic refraction. When myopia was defined as SE of ≤−0.75 D under non-cycloplegic conditions, there was no difference between cycloplegic and non-cycloplegic open-field autorefraction prevalence estimates (12%; 95% CI, 8% to 15%; p = 1.00). Overall, non-cycloplegic refraction underestimates hyperopia and overestimates myopia; but for subjects with myopia, this difference is minimal and not clinically significant. A threshold of SE ≤ −0.75 D agrees well for the estimation of myopia prevalence among children when using non-cycloplegic refraction and is comparable with the standard definition of cycloplegic myopic refraction of SE ≤ −0.50 D.