Time spent in outdoor activities in relation to myopia prevention and control: a meta-analysis and systematic review.

PubMed

Xiong, Shuyu; Sankaridurg, Padmaja; Naduvilath, Thomas; Zang, Jiajie; Zou, Haidong; Zhu, Jianfeng; Lv, Minzhi; He, Xiangui; Xu, Xun

2017-09-01

Outdoor time is considered to reduce the risk of developing myopia. The purpose is to evaluate the evidence for association between time outdoors and (1) risk of onset of myopia (incident/prevalent myopia); (2) risk of a myopic shift in refractive error and c) risk of progression in myopes only. A systematic review followed by a meta-analysis and a dose-response analysis of relevant evidence from literature was conducted. PubMed, EMBASE and the Cochrane Library were searched for relevant papers. Of the 51 articles with relevant data, 25 were included in the meta-analysis and dose-response analysis. Twenty-three of the 25 articles involved children. Risk ratio (RR) for binary variables and weighted mean difference (WMD) for continuous variables were conducted. Mantel-Haenszel random-effects model was used to pool the data for meta-analysis. Statistical heterogeneity was assessed using the I 2 test with I 2  ≥ 50% considered to indicate high heterogeneity. Additionally, subgroup analyses (based on participant's age, prevalence of myopia and study type) and sensitivity analyses were conducted. A significant protective effect of outdoor time was found for incident myopia (clinical trials: risk ratio (RR) = 0.536, 95% confidence interval (CI) = 0.338 to 0.850; longitudinal cohort studies: RR = 0.574, 95% CI = 0.395 to 0.834) and prevalent myopia (cross-sectional studies: OR = 0.964, 95% CI = 0.945 to 0.982). With dose-response analysis, an inverse nonlinear relationship was found with increased time outdoors reducing the risk of incident myopia. Also, pooled results from clinical trials indicated that when outdoor time was used as an intervention, there was a reduced myopic shift of -0.30 D (in both myopes and nonmyopes) compared with the control group (WMD = -0.30, 95% CI = -0.18 to -0.41) after 3 years of follow-up. However, when only myopes were considered, dose-response analysis did not find a relationship between time outdoors and myopic progression (R 2  = 0.00064). Increased time outdoors is effective in preventing the onset of myopia as well as in slowing the myopic shift in refractive error. But paradoxically, outdoor time was not effective in slowing progression in eyes that were already myopic. Further studies evaluating effect of outdoor in various doses and objective measurements of time outdoors may help improve our understanding of the role played by outdoors in onset and management of myopia. © 2017 The Authors. Acta Ophthalmologica published by John Wiley & Sons Ltd on behalf of Acta Ophthalmologica Scandinavica Foundation.

Myopia Control: A Review.

PubMed

Walline, Jeffrey J

2016-01-01

Slowing the progression of myopia has become a considerable concern for parents of myopic children. At the same time, clinical science is rapidly advancing the knowledge about methods to slow myopia progression. This article reviews the peer-reviewed literature regarding several modalities attempting to control myopia progression. Several strategies have been shown to be ineffective for myopia control, including undercorrection of myopic refractive error, alignment fit gas-permeable contact lenses, outdoor time, and bifocal of multifocal spectacles. However, a recent randomized clinical trial fitted progressing myopic children with executive bifocals for 3 years and found a 39% slowing of myopia progression for bifocal-only spectacles and 50% treatment effect for bifocal spectacles with base-in prism, although there was not a significant difference in progression between the bifocal-only and bifocal plus prism groups. Interestingly, outdoor time has shown to be effective for reducing the onset of myopia but not for slowing the progression of myopic refractive error. More effective methods of myopia control include orthokeratology, soft bifocal contact lenses, and antimuscarinic agents. Orthokeratology and soft bifocal contact lenses are both thought to provide myopic blur to the retina, which acts as a putative cue to slow myopic eye growth. Each of these myopia control methods provides, on average, slightly less than 50% slowing of myopia progression. All studies have shown clinically meaningful slowing of myopia progression, including several randomized clinical trials. The most investigated antimuscarinic agents include pirenzepine and atropine. Pirenzepine slows myopia progression by approximately 40%, but it is not commercially available in the United States. Atropine provides the best myopia control, but the cycloplegic and mydriatic side effects render it a rarely prescribed myopia control agent in the United States. However, low-concentration atropine has been shown to provide effective myopia control with far fewer side effects than 1.0% atropine. Finally, two agents, low-concentration atropine and outdoor time have been shown to reduce the likelihood of myopia onset. Over the past few years, much has been learned about how to slow the progression of nearsightedness in children, but we still have a lot to learn.

Long-Term Observation of Coexistence of Posterior Polymorphous Corneal Dystrophy, Resultant High Myopia and Nonkeratoconic Developing Corneal Astigmatism: A Case Report of 7-Year Tracking in a Chinese Boy.

PubMed

Shen, Jianqin; Chixin, Du; Gu, Yangshun

2015-06-01

Posterior polymorphous corneal dystrophy (PPCD) is an extremely rare, bilateral, and inherited disorder, which affects the corneal endothelium and Descemet's membrane. Few PPCD cases in Chinese patients have been published so far. As far as we know, there are few studies which focused on the associations between PPCD and high myopia either. Here we report a rare case of coexistence of posterior polymorphous corneal dystrophy, resultant high myopia and with-the-rule developing corneal astigmatism in a young Chinese boy. A 6-year-old boy was first referred to our department 7 years ago, complaining of bilateral poor vision. Examinations of both eyes including ophthalmologic examination, cycloplegic refraction examination, confocal microscopy findings, and corneal topography were performed. Bilateral small aggregates of vesicular lesions and patchy hyperreflectivity were observed at the level of the Descemet's membrane on confocal microscopy, which is consistent with typical PPCD. Optometry and corneal topography examinations showed a resultant high myopia. Ocular examinations were performed annually to follow up with the patient in the past 7 years. The corneal lesions remained stable whereas an axial elongation and a sharp increase in both spherical and cylindrical equivalent power were observed. Close follow-ups including thorough scrutiny of the endothelium and systematic ocular ancillary examinations are essential for patients with PPCD. The pathological coexistence of PPCD and high myopia in our case is possibly due to a shared etiological pathway or genetic background. Advanced genetic analysis on similar cases is expected if more samples can be provided.

Global variations and time trends in the prevalence of childhood myopia, a systematic review and quantitative meta-analysis: implications for aetiology and early prevention

PubMed Central

Rudnicka, Alicja R; Kapetanakis, Venediktos V; Wathern, Andrea K; Gilmartin, Bernard; Whincup, Peter H; Cook, Derek G; Owen, Christopher G

2016-01-01

The aim of this review was to quantify the global variation in childhood myopia prevalence over time taking account of demographic and study design factors. A systematic review identified population-based surveys with estimates of childhood myopia prevalence published by February 2015. Multilevel binomial logistic regression of log odds of myopia was used to examine the association with age, gender, urban versus rural setting and survey year, among populations of different ethnic origins, adjusting for study design factors. 143 published articles (42 countries, 374 349 subjects aged 1–18 years, 74 847 myopia cases) were included. Increase in myopia prevalence with age varied by ethnicity. East Asians showed the highest prevalence, reaching 69% (95% credible intervals (CrI) 61% to 77%) at 15 years of age (86% among Singaporean-Chinese). Blacks in Africa had the lowest prevalence; 5.5% at 15 years (95% CrI 3% to 9%). Time trends in myopia prevalence over the last decade were small in whites, increased by 23% in East Asians, with a weaker increase among South Asians. Children from urban environments have 2.6 times the odds of myopia compared with those from rural environments. In whites and East Asians sex differences emerge at about 9 years of age; by late adolescence girls are twice as likely as boys to be myopic. Marked ethnic differences in age-specific prevalence of myopia exist. Rapid increases in myopia prevalence over time, particularly in East Asians, combined with a universally higher risk of myopia in urban settings, suggest that environmental factors play an important role in myopia development, which may offer scope for prevention. PMID:26802174

Correlation between choroidal thickness and degree of myopia assessed with enhanced depth imaging optical coherence tomography.

PubMed

El-Shazly, Amany A; Farweez, Yousra A; ElSebaay, Marwa E; El-Zawahry, Walid M A

2017-08-30

To assess the choroidal thickness in different degrees of myopia using enhanced depth imaging optical coherence tomography (EDI-OCT) compared with healthy subjects. We included 240 patients with myopia and 60 emmetropes as controls. Participants underwent full ophthalmologic examination, axial length measurement, and EDI-OCT imaging of the choroid. Choroidal thickness (CT) was measured at 5 locations, including subfoveal (SFCT), 2 mm nasal, temporal, upper, and lower to fovea. Choroidal thickness was significantly lower in myopic eyes compared to controls. Regardless of the degree of myopia, nasal regions showed the lowest CT with decremental pattern with advance of myopia (low myopia 279.00 ± 24.50 µm, moderate myopia 269.58 ± 20.69 µm, high myopia 189.58 ± 25.95 µm, advanced myopia 96.75 ± 24.83 µm). Highest CT was variable according to the degree of myopia with decremental pattern with advance of myopia (low myopia in subfoveal region 354.40 ± 35.14 µm, moderate myopia in temporal region 337.87 ± 35.75 µm, high myopia in lower region 312.15 ± 38.90 µm, and advanced myopia in upper region 201.25 ± 18.27 µm). Axial length showed significant negative correlation with SFCT and CT in different studied regions. Different degrees of myopia showed thinner choroidal thickness than that of normal control eyes with decremental thinning with progress of myopia. This might be secondary to the longer axial length, which was the determining factor in some locations such as subfoveal, nasal, and upper CT.

Insight into the molecular genetics of myopia

PubMed Central

Li, Jiali

2017-01-01

Myopia is the most common cause of visual impairment worldwide. Genetic and environmental factors contribute to the development of myopia. Studies on the molecular genetics of myopia are well established and have implicated the important role of genetic factors. With linkage analysis, association studies, sequencing analysis, and experimental myopia studies, many of the loci and genes associated with myopia have been identified. Thus far, there has been no systemic review of the loci and genes related to non-syndromic and syndromic myopia based on the different approaches. Such a systemic review of the molecular genetics of myopia will provide clues to identify additional plausible genes for myopia and help us to understand the molecular mechanisms underlying myopia. This paper reviews recent genetic studies on myopia, summarizes all possible reported genes and loci related to myopia, and suggests implications for future studies on the molecular genetics of myopia. PMID:29386878

Insight into the molecular genetics of myopia.

PubMed

Li, Jiali; Zhang, Qingjiong

2017-01-01

Myopia is the most common cause of visual impairment worldwide. Genetic and environmental factors contribute to the development of myopia. Studies on the molecular genetics of myopia are well established and have implicated the important role of genetic factors. With linkage analysis, association studies, sequencing analysis, and experimental myopia studies, many of the loci and genes associated with myopia have been identified. Thus far, there has been no systemic review of the loci and genes related to non-syndromic and syndromic myopia based on the different approaches. Such a systemic review of the molecular genetics of myopia will provide clues to identify additional plausible genes for myopia and help us to understand the molecular mechanisms underlying myopia. This paper reviews recent genetic studies on myopia, summarizes all possible reported genes and loci related to myopia, and suggests implications for future studies on the molecular genetics of myopia.

Association and interaction of myopia with SNP markers rs13382811 and rs6469937 at ZFHX1B and SNTB1 in Han Chinese and European populations.

PubMed

Li, Jiali; Jiao, Xiaodong; Zhang, Qingjiong; Hejtmancik, J Fielding

2017-01-01

Previously, a genome-wide association study (GWAS) identified rs13382811 (near ZFHX1B) and rs6469937 (near SNTB1) to be associated with high myopia. The present study evaluates the association of these two single nucleotide polymorphisms (SNPs) with moderate to high myopia in two Chinese cohorts and two cohorts of European populations. Two Chinese university student cohorts, including one with 300 unrelated subjects with high myopia and 308 emmetropic controls from Guangzhou and a second with 96 unrelated individuals with moderate to high myopia and 96 emmetropic controls of Chaoshanese origin in Guangzhou, were enrolled in this study. Two SNPs, rs6469937 and rs13382811, were selected for genotyping based on their reported associations with severe myopia. The SNPs were genotyped via DNA sequencing. In addition, association analysis of both SNPs was performed using genotype data from the database of Genotypes and Phenotypes (dbGaP) involving a total of 2,423 samples in two independent cohorts of European-derived populations, as follows: Kooperative Gesundheitsforschung in der Region Augsburg (KORA) and TwinsUK. The allelic and genotypic distribution among cases and controls were analyzed using the Chi-square test. Logistic regression was used to evaluate the SNP-SNP interaction. Fisher's exact test was used for two-SNP comparisons. In the Guangzhou cohort, SNP rs13382811 near ZFHX1B showed significant association with high myopia ( p allelic = 0.0001, p genotypic = 4.07 × 10 -5 ), with the minor T allele showing an increased risk of high myopia (odds ratio [OR] = 1.68, 95% confidence interval [CI] = 1.28-2.20). SNP rs6469937 near SNTB1 showed nominal evidence of association ( p allelic = 0.0085, p genotypic = 0.0166), which did not withstand correction for multiple testing. No significant association was detected in the smaller Chaoshan cohort alone. The association of SNPs rs13382811 and rs6469937 remained significant when both Han Chinese cohorts were combined ( p allelic = 0.0033 and 0.0016, respectively), and it was also significant under the genotypic test ( p genotypic = 0.0036 and 0.0053, respectively). When both SNPs were considered together under a recessive model, their significance increased ( p = 8.37 × 10 -4 ), as did their effect (OR = 4.09, 95%CI = 1.7-9.8). The association between either of these two SNPs alone and myopia did not replicate significantly in the combined cohorts of European descent, providing only suggestive results ( p allelic = 0.0088 for rs13382811 and p allelic = 0.0319 for rs6469937). However, the effects of the combined SNPs showed significant association ( p = 8.2 × 10 -4 ; OR = 1.56, 95%CI = 1.2-2.0). While the risk for myopia increased with risk alleles from both SNPs, the increase was additive rather representing a multiplicative interaction in both populations. Our study confirms that the two susceptibility loci ZFHX1B and SNTB1 are associated with moderate to high myopia in a Han Chinese population, as well as in a European population, when both SNPs are combined. These results confirm previous reports of their associations, extend these observations to a European population, and suggest that additional interactive and possibly population-specific genetic or environmental factors may affect their contribution to myopia.

[Displacement of the posterior part of the eyeball in myopia].

PubMed

Akizawa, Yasuko; Masahiro, Ida

2006-12-01

The principal aim of this study was to investigate displacement of the posterior part of the eyeball within the muscle cone in myopic eyes, particularly in moderately myopic subjects as well as in high myopes. Secondly, the correlation of the amount of displacement and the outer axial length of the globe was studied. The direction of displacement was also examined to clarify whether the eyeball tends to shift toward a certain direction. Seven patients with moderate myopia (moderate myopia group), fifteen patients with high myopia without esotropia (high myopia group), five patients with high myopia and esotropia (myopic esotropia group), and twenty-two controls (control group) were examined. Using magnetic resonance imaging, the outer axial length and the displacement of the posterior portion of the eyeball in the muscle cone were measured. In order to eliminate interindividual differences in the facial configuration, the coronal scanning was done perpendicularly to the orbital axis. The displacement was measured in a plane 4 mm anterior to the globe-optic nerve junction. The displacement was represented by the distance and direction of the globe center from the center of the muscle cone. In the moderate myopia group, there was no displacement of the posterior part of the eyeball in the muscle cone. It was the same as in the control group. But among the three groups, the displacement (mean standard deviation) was significantly greater in the myopic esotropia group (1.53 +/- 0.49 mm) and the high myopia group (0.94 +/- 0.52 mm) than in the control group (0.11 +/- 0.18 mm) (one way ANOVA and multiple comparison). The outer axial length and the distance of the displacement in all cases was significantly correlated (r = 0.87, p = 0.01). Moreover, the posterior part of the eyeball of the myopic esotropia group and the high myopia group was displaced superiorly and temporally. The posterior part of the eyeball of myopic eyes was displaced superotemporally in the muscle cone regardless of the presence of esotropia, and the amount of displacement was significantly correlated with the outer axial length. The more the eyeball expanded, the farther it was displaced. In the end, it was thought that the most elongated high myopic eyes would dislocate out of the muscle cone.

Efficacy and Adverse Effects of Atropine in Childhood Myopia: A Meta-analysis.

PubMed

Gong, Qianwen; Janowski, Miroslaw; Luo, Mi; Wei, Hong; Chen, Bingjie; Yang, Guoyuan; Liu, Longqian

2017-06-01

Some uncertainty about the clinical value and dosing of atropine for the treatment of myopia in children remains. To evaluate the efficacy vs the adverse effects of various doses of atropine in the therapy for myopia in children. Data were obtained from PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials, from inception to April 30, 2016. The reference lists of published reviews and clinicaltrials.gov were searched for additional relevant studies. Key search terms included myopia, refractive errors, and atropine. Only studies published in English were included. Randomized clinical trials and cohort studies that enrolled patients younger than 18 years with myopia who received atropine in at least 1 treatment arm and that reported the annual rate of myopia progression and/or any adverse effects of atropine therapy were included in the analysis. Two reviewers independently abstracted the data. Heterogeneity was statistically quantified by Q, H, and I2 statistics, and a meta-analysis was performed using the random-effects model. The Cochrane Collaboration 6 aspects of bias and the Newcastle-Ottawa Scale were used to assess the risk for bias. The primary outcome was a difference in efficacy and the presence of adverse effects at different doses of atropine vs control conditions. The secondary outcomes included the differences in adverse effects between Asian and white patients. Nineteen unique studies involving 3137 unique children were included in the analysis. The weighted mean differences between the atropine and control groups in myopia progression were 0.50 diopters (D) per year (95% CI, 0.24-0.76 D per year) for low-dose atropine, 0.57 D per year (95% CI, 0.43-0.71 D per year) for moderate-dose atropine, and 0.62 D per year (95% CI, 0.45-0.79 D per year) for high-dose atropine (P < .001), which translated to a high effect size (Cohen d, 0.97, 1.76, and 1.94, respectively). All doses of atropine, therefore, were equally beneficial with respect to myopia progression (P = .15). High-dose atropine were associated with more adverse effects, such as the 43.1% incidence of photophobia compared with 6.3% for low-dose atropine and 17.8% for moderate-dose atropine (χ22 = 7.05; P = .03). In addition, differences in the incidence of adverse effects between Asian and white patients were not identified (χ21 = 0.81; P = .37 for photophobia). This meta-analysis suggests that the efficacy of atropine is dose independent within this range, whereas the adverse effects are dose dependent.

How to effectively manage myopia.

PubMed

Chuang, Ann Yi-Chiun

2017-01-01

Myopia has become epidemic in the world. Without effective control, the progression may lead to excessive myopia with severe complications affecting vision and ocular alignment. The genetic factors and environmental factors of myopia are closely interrelated to each other. Asian ethnicity and parental myopia, among other genetic factors, influence the refractive outcome dramatically when environmental risk factors such as hours of near work and reading distance are analyzed. Outdoor activities are protective measures that retard myopia progression. Total time under the sun and not the specific outdoor activities are contributing factors. Current effective treatments for myopia include atropine of high, moderate, and low doses, relative peripheral myopia-inducing devices, and bifocal spectacles including prism bifocal spectacle lenses. Although atropine is considered highly effective in randomized controlled trials, it is not well tolerated in a clinical setting, especially in high dosage. Since the severity of rebound effect of atropine after cessation of usage and the side effects are directly related to the concentration of the medication, it is recommended that low-dose atropine is used in the initial attempt. Higher concentration for better control can be considered when compliance is observed. Devices that induce relative peripheral myopia such as orthokeratology are moderately effective interventions that are well accepted by children who wish to be spectacle free. Bifocal spectacles generally have low effect in myopia control. Prism bifocal spectacle lenses may have a special niche in myopia retardation for patients with low lags of accommodation.

Myopia in young patients with type 1 diabetes mellitus.

PubMed

Handa, Swati; Chia, Audrey; Htoon, Hla Myint; Lam, Pin Min; Yap, Fabian; Ling, Yvonne

2015-08-01

This study aimed to evaluate the proportion of young patients with type 1 diabetes mellitus (T1DM) who have myopia, as well as the risk factors associated with myopia in this group. In this cross-sectional study, patients aged < 21 years with T1DM for ≥ 1 year underwent a comprehensive eye examination. Presence of parental myopia, and average hours of near-work and outdoor activity were estimated using a questionnaire. Annualised glycosylated haemoglobin (HbA1c), defined as the mean of the last three HbA1c readings taken over the last year, was calculated. Multivariate analysis using genetic, environmental and diabetes-related factors was done to evaluate risk factors associated with myopia. Of the 146 patients (mean age 12.5 ± 3.6 years) recruited, 66.4% were Chinese and 57.5% were female. Myopia (i.e. spherical equivalent [SE] of -0.50 D or worse) was present in 96 (65.8%) patients. The proportion of patients with myopia increased from 25.0% and 53.6% in those aged < 7.0 years and 7.0-9.9 years, respectively, to 59.2% and 78.4% in those aged 10.0-11.9 years and ≥ 12.0 years, respectively. Higher levels of SE were associated with lower parental myopia (p = 0.024) and higher annualised HbA1c (p = 0.011). Compared to the background population, the proportion of myopia in young patients with T1DM was higher in those aged < 10 years but similar in the older age group. Myopia was associated with a history of parental myopia. Environmental risk factors and poor glycaemic control were not related to higher myopia risk.

Global variations and time trends in the prevalence of childhood myopia, a systematic review and quantitative meta-analysis: implications for aetiology and early prevention.

PubMed

Rudnicka, Alicja R; Kapetanakis, Venediktos V; Wathern, Andrea K; Logan, Nicola S; Gilmartin, Bernard; Whincup, Peter H; Cook, Derek G; Owen, Christopher G

2016-07-01

The aim of this review was to quantify the global variation in childhood myopia prevalence over time taking account of demographic and study design factors. A systematic review identified population-based surveys with estimates of childhood myopia prevalence published by February 2015. Multilevel binomial logistic regression of log odds of myopia was used to examine the association with age, gender, urban versus rural setting and survey year, among populations of different ethnic origins, adjusting for study design factors. 143 published articles (42 countries, 374 349 subjects aged 1-18 years, 74 847 myopia cases) were included. Increase in myopia prevalence with age varied by ethnicity. East Asians showed the highest prevalence, reaching 69% (95% credible intervals (CrI) 61% to 77%) at 15 years of age (86% among Singaporean-Chinese). Blacks in Africa had the lowest prevalence; 5.5% at 15 years (95% CrI 3% to 9%). Time trends in myopia prevalence over the last decade were small in whites, increased by 23% in East Asians, with a weaker increase among South Asians. Children from urban environments have 2.6 times the odds of myopia compared with those from rural environments. In whites and East Asians sex differences emerge at about 9 years of age; by late adolescence girls are twice as likely as boys to be myopic. Marked ethnic differences in age-specific prevalence of myopia exist. Rapid increases in myopia prevalence over time, particularly in East Asians, combined with a universally higher risk of myopia in urban settings, suggest that environmental factors play an important role in myopia development, which may offer scope for prevention. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Nature versus nurture: A systematic approach to elucidate gene-environment interactions in the development of myopic refractive errors.

PubMed

Miraldi Utz, Virginia

2017-01-01

Myopia is the most common eye disorder and major cause of visual impairment worldwide. As the incidence of myopia continues to rise, the need to further understand the complex roles of molecular and environmental factors controlling variation in refractive error is of increasing importance. Tkatchenko and colleagues applied a systematic approach using a combination of gene set enrichment analysis, genome-wide association studies, and functional analysis of a murine model to identify a myopia susceptibility gene, APLP2. Differential expression of refractive error was associated with time spent reading for those with low frequency variants in this gene. This provides support for the longstanding hypothesis of gene-environment interactions in refractive error development.

Interventions to Reduce Myopia Progression in Children.

PubMed

Tay, Su Ann; Farzavandi, Sonal; Tan, Donald

2017-03-01

Efforts to reduce the progression of myopia in childhood are on the rise, due to an increasing incidence of myopia worldwide and its associated sight-threatening complications. Interventions are aimed at reducing myopia in childhood and include environmental considerations, spectacles, contact lenses, and pharmacological agents. We reviewed recent literature with interventions aimed at reducing myopia progression in children and found that a number of interventions were significant in reducing the progression of myopia. Of these interventions, atropine showed the largest dose-related effect on myopia progression control. Although higher doses are associated with side effects of pupil dilatation, loss of accommodation, near vision blur, and rebound phenomenon, low-dose atropine has also been shown to provide effective myopia control with minimal side effects and rebound. To a lesser degree, bifocal soft contact lenses have also been shown to be effective in reducing the progression of myopia, though compliance is an issue. Similarly, orthokeratology lenses have also been shown to be effective in reducing axial length elongation and myopia progression, though long-term data on its rebound effects are unavailable.

Global Prevalence of Myopia and High Myopia and Temporal Trends from 2000 through 2050.

PubMed

Holden, Brien A; Fricke, Timothy R; Wilson, David A; Jong, Monica; Naidoo, Kovin S; Sankaridurg, Padmaja; Wong, Tien Y; Naduvilath, Thomas J; Resnikoff, Serge

2016-05-01

Myopia is a common cause of vision loss, with uncorrected myopia the leading cause of distance vision impairment globally. Individual studies show variations in the prevalence of myopia and high myopia between regions and ethnic groups, and there continues to be uncertainty regarding increasing prevalence of myopia. Systematic review and meta-analysis. We performed a systematic review and meta-analysis of the prevalence of myopia and high myopia and estimated temporal trends from 2000 to 2050 using data published since 1995. The primary data were gathered into 5-year age groups from 0 to ≥100, in urban or rural populations in each country, standardized to definitions of myopia of -0.50 diopter (D) or less and of high myopia of -5.00 D or less, projected to the year 2010, then meta-analyzed within Global Burden of Disease (GBD) regions. Any urban or rural age group that lacked data in a GBD region took data from the most similar region. The prevalence data were combined with urbanization data and population data from United Nations Population Department (UNPD) to estimate the prevalence of myopia and high myopia in each country of the world. These estimates were combined with myopia change estimates over time derived from regression analysis of published evidence to project to each decade from 2000 through 2050. We included data from 145 studies covering 2.1 million participants. We estimated 1406 million people with myopia (22.9% of the world population; 95% confidence interval [CI], 932-1932 million [15.2%-31.5%]) and 163 million people with high myopia (2.7% of the world population; 95% CI, 86-387 million [1.4%-6.3%]) in 2000. We predict by 2050 there will be 4758 million people with myopia (49.8% of the world population; 3620-6056 million [95% CI, 43.4%-55.7%]) and 938 million people with high myopia (9.8% of the world population; 479-2104 million [95% CI, 5.7%-19.4%]). Myopia and high myopia estimates from 2000 to 2050 suggest significant increases in prevalences globally, with implications for planning services, including managing and preventing myopia-related ocular complications and vision loss among almost 1 billion people with high myopia. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Interventions to slow progression of myopia in children

PubMed Central

Walline, Jeffrey J; Lindsley, Kristina; Vedula, Satyanarayana S; Cotter, Susan A; Mutti, Donald O; Twelker, J. Daniel

2012-01-01

Background Nearsightedness (myopia) causes blurry vision when looking at distant objects. Highly nearsighted people are at greater risk of several vision-threatening problems such as retinal detachments, choroidal atrophy, cataracts and glaucoma. Interventions that have been explored to slow the progression of myopia include bifocal spectacles, cycloplegic drops, intraocular pressure-lowering drugs, muscarinic receptor antagonists and contact lenses. The purpose of this review was to systematically assess the effectiveness of strategies to control progression of myopia in children. Objectives To assess the effects of several types of interventions, including eye drops, undercorrection of nearsightedness, multifocal spectacles and contact lenses, on the progression of nearsightedness in myopic children younger than 18 years. We compared the interventions of interest with each other, to single vision lenses (SVLs) (spectacles), placebo or no treatment. Search methods We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2011, Issue 10), MEDLINE (January 1950 to October 2011), EMBASE (January 1980 to October 2011), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to October 2011), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com) and ClinicalTrials.gov (http://clinicaltrials.gov). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 11 October 2011. We also searched the reference lists and Science Citation Index for additional, potentially relevant studies. Selection criteria We included randomized controlled trials (RCTs) in which participants were treated with spectacles, contact lenses or pharmaceutical agents for the purpose of controlling progression of myopia. We excluded trials where participants were older than 18 years at baseline or participants had less than −0.25 diopters (D) spherical equivalent myopia. Data collection and analysis Two review authors independently extracted data and assessed the risk of bias for each included study. When possible, we analyzed data with the inverse variance method using a fixed-effect or random-effects model, depending on the number of studies and amount of heterogeneity detected. Main results We included 23 studies (4696 total participants) in this review, with 17 of these studies included in quantitative analysis. Since we only included RCTs in the review, the studies were generally at low risk of bias for selection bias. Undercorrection of myopia was found to increase myopia progression slightly in two studies; children who were undercorrected progressed on average 0.15 D (95% confidence interval (CI) −0.29 to 0.00) more than the fully corrected SVLs wearers at one year. Rigid gas permeable contact lenses (RGPCLs) were found to have no evidence of effect on myopic eye growth in two studies (no meta-analysis due to heterogeneity between studies). Progressive addition lenses (PALs), reported in four studies, and bifocal spectacles, reported in four studies, were found to yield a small slowing of myopia progression. For seven studies with quantitative data at one year, children wearing multifocal lenses, either PALs or bifocals, progressed on average 0.16 D (95% CI 0.07 to 0.25) less than children wearing SVLs. The largest positive effects for slowing myopia progression were exhibited by anti-muscarinic medications. At one year, children receiving pirenzepine gel (two studies), cyclopentolate eye drops (one study), or atropine eye drops (two studies) showed significantly less myopic progression compared with children receiving placebo (mean differences (MD) 0.31 (95% CI 0.17 to 0.44), 0.34 (95% CI 0.08 to 0.60), and 0.80 (95% CI 0.70 to 0.90), respectively). Authors’ conclusions The most likely effective treatment to slow myopia progression thus far is anti-muscarinic topical medication. However, side effects of these medications include light sensitivity and near blur. Also, they are not yet commercially available, so their use is limited and not practical. Further information is required for other methods of myopia control, such as the use of corneal reshaping contact lenses or bifocal soft contact lenses (BSCLs) with a distance center are promising, but currently no published randomized clinical trials exist. PMID:22161388

Physical activity in relation to development and progression of myopia - a systematic review.

PubMed

Suhr Thykjaer, Anne; Lundberg, Kristian; Grauslund, Jakob

2017-11-01

On a global scale, myopia is one of the most common causes of visual impairment. Given the increasing prevalence of myopia, it is vital to understand the pathogenesis and to identify potential interventions. Some studies have described physical activity as a potential correlation for myopia. The objective of this study was to make a systematic review regarding the correlation between physical activity and myopia. A total of 263 papers were identified in a systematic database search of PubMed/Medline and Embase. Five steps of screening removed studies of a low evidence quality and animal studies. Studies included had refractive error and physical activity (as measured by questionnaires, accelerometers and cycle ergometers) as separate, well-defined outcomes. Nine studies (six cross-sectional, two cohorts and one case-control study) with a total of 17 634 subjects were included. Six studies demonstrated a reverse association between physical activity and myopia. Three studies supported this, but also attributed the results to time spent outdoors and not physical activity per se. One cross-sectional study found no relation. We could not identify trends among the papers regarding the type of studies, population sizes, ethnicity or age of study subjects. A consistent relationship between more physical activity and less myopia was observed. No evidence of physical activity as an independent risk factor for myopia was seen. Evidence suggests that time outdoors remain the most important factor. Future studies should include objective measurements of physical activity to determine a potential independent effect. Distinction between physical activity and outdoor exposure remains important. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Violet Light Exposure Can Be a Preventive Strategy Against Myopia Progression.

PubMed

Torii, Hidemasa; Kurihara, Toshihide; Seko, Yuko; Negishi, Kazuno; Ohnuma, Kazuhiko; Inaba, Takaaki; Kawashima, Motoko; Jiang, Xiaoyan; Kondo, Shinichiro; Miyauchi, Maki; Miwa, Yukihiro; Katada, Yusaku; Mori, Kiwako; Kato, Keiichi; Tsubota, Kinya; Goto, Hiroshi; Oda, Mayumi; Hatori, Megumi; Tsubota, Kazuo

2017-02-01

Prevalence of myopia is increasing worldwide. Outdoor activity is one of the most important environmental factors for myopia control. Here we show that violet light (VL, 360-400nm wavelength) suppresses myopia progression. First, we confirmed that VL suppressed the axial length (AL) elongation in the chick myopia model. Expression microarray analyses revealed that myopia suppressive gene EGR1 was upregulated by VL exposure. VL exposure induced significantly higher upregulation of EGR1 in chick chorioretinal tissues than blue light under the same conditions. Next, we conducted clinical research retrospectively to compare the AL elongation among myopic children who wore eyeglasses (VL blocked) and two types of contact lenses (partially VL blocked and VL transmitting). The data showed the VL transmitting contact lenses suppressed myopia progression most. These results suggest that VL is one of the important outdoor environmental factors for myopia control. Since VL is apt to be excluded from our modern society due to the excessive UV protection, VL exposure can be a preventive strategy against myopia progression. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Posterior Corneal Characteristics of Cataract Patients with High Myopia

PubMed Central

Jing, Qinghe; Tang, Yating; Qian, Dongjin; Lu, Yi; Jiang, Yongxiang

2016-01-01

Purpose To evaluate the characteristics of the posterior corneal surface in patients with high myopia before cataract surgery. Methods We performed a cross-sectional study at the Eye and ENT Hospital of Fudan University, Shanghai, China. Corneal astigmatism and axial length were measured with a rotating Scheimpflug camera (Pentacam) and partial coherence interferometry (IOLMaster) in a high-myopia study group of 167 eyes (axial length ≥ 26 mm) and a control group of 150 eyes (axial length > 20 mm and < 25 mm). Results Total corneal astigmatism and anterior corneal astigmatism values were higher in the high-myopia group than in the control group. There was no significant difference in posterior corneal astigmatism between the high-myopia study group and the control group. In the study group, the mean posterior corneal astigmatism (range 0 – −0.9 diopters) was –0.29 diopters (D) ± 0.17 standard deviations (SD). The steep corneal meridian was aligned vertically (60°–120°) in 87.43% of eyes for the posterior corneal surface, and did not change with increasing age. There was a significant correlation (r = 0.235, p = 0.002) between posterior corneal astigmatism and anterior corneal astigmatism, especially when the anterior corneal surface showed with-the-rule (WTR) astigmatism (r = 0.452, p = 0.000). There was a weak negative correlation between posterior corneal astigmatism and age (r = –0.15, p = 0.053) in the high-myopia group. Compared with total corneal astigmatism values, the anterior corneal measurements alone overestimated WTR astigmatism by a mean of 0.27 ± 0.18 D in 68.75% of eyes, underestimated against-the-rule (ATR) astigmatism by a mean of 0.41 ± 0.28 D in 88.89% of eyes, and underestimated oblique astigmatism by a mean of 0.24 ± 0.13 D in 63.64% of eyes. Conclusions Posterior corneal astigmatism decreased with age and remained as ATR astigmatism in most cases of high myopia. There was a significant correlation between posterior corneal astigmatism and anterior corneal astigmatism when anterior corneal astigmatism was WTR. If posterior corneal astigmatism is not accounted for when selecting toric intraocular lenses for high-myopia patients, the use of anterior corneal astigmatism measurements alone will lead to overestimation of WTR astigmatism and underestimation of ATR and oblique astigmatism. PMID:27603713

Posterior Corneal Characteristics of Cataract Patients with High Myopia.

PubMed

Jing, Qinghe; Tang, Yating; Qian, Dongjin; Lu, Yi; Jiang, Yongxiang

2016-01-01

To evaluate the characteristics of the posterior corneal surface in patients with high myopia before cataract surgery. We performed a cross-sectional study at the Eye and ENT Hospital of Fudan University, Shanghai, China. Corneal astigmatism and axial length were measured with a rotating Scheimpflug camera (Pentacam) and partial coherence interferometry (IOLMaster) in a high-myopia study group of 167 eyes (axial length ≥ 26 mm) and a control group of 150 eyes (axial length > 20 mm and < 25 mm). Total corneal astigmatism and anterior corneal astigmatism values were higher in the high-myopia group than in the control group. There was no significant difference in posterior corneal astigmatism between the high-myopia study group and the control group. In the study group, the mean posterior corneal astigmatism (range 0 - -0.9 diopters) was -0.29 diopters (D) ± 0.17 standard deviations (SD). The steep corneal meridian was aligned vertically (60°-120°) in 87.43% of eyes for the posterior corneal surface, and did not change with increasing age. There was a significant correlation (r = 0.235, p = 0.002) between posterior corneal astigmatism and anterior corneal astigmatism, especially when the anterior corneal surface showed with-the-rule (WTR) astigmatism (r = 0.452, p = 0.000). There was a weak negative correlation between posterior corneal astigmatism and age (r = -0.15, p = 0.053) in the high-myopia group. Compared with total corneal astigmatism values, the anterior corneal measurements alone overestimated WTR astigmatism by a mean of 0.27 ± 0.18 D in 68.75% of eyes, underestimated against-the-rule (ATR) astigmatism by a mean of 0.41 ± 0.28 D in 88.89% of eyes, and underestimated oblique astigmatism by a mean of 0.24 ± 0.13 D in 63.64% of eyes. Posterior corneal astigmatism decreased with age and remained as ATR astigmatism in most cases of high myopia. There was a significant correlation between posterior corneal astigmatism and anterior corneal astigmatism when anterior corneal astigmatism was WTR. If posterior corneal astigmatism is not accounted for when selecting toric intraocular lenses for high-myopia patients, the use of anterior corneal astigmatism measurements alone will lead to overestimation of WTR astigmatism and underestimation of ATR and oblique astigmatism.

The differences in level of trait anxiety among girls and boys aged 13-17 years with myopia and emmetropia.

PubMed

Łazarczyk, Joanna B; Urban, Beata; Konarzewska, Beata; Szulc, Agata; Bakunowicz-Łazarczyk, Alina; Żmudzka, Ewa; Kowzan, Urszula; Waszkiewicz, Napoleon; Juszczyk-Zajkowska, Karolina

2016-11-14

A significant increase in myopia among children and teenagers can be observed all over the world. Yet at the same time, there is still an insignificant number of studies concerning this health problem. The aim of this study was to assess the level of trait anxiety among myopic group of teenagers in comparison to teenagers with emmetropia, and to confirm whether the level of trait anxiety relates to age and gender. Two hundred thirty-nine students aged 13-17 years were included in the study. The study group comprised 114 persons with myopia (81 girls and 33 boys), while the control group comprised 125 persons without refractive error (79 girls and 46 boys). Volunteers completed a set of questionnaires including: personal data, State-Trait Anxiety Inventory for Children (STAIC) (13-14 year-olds), or State-Trait Anxiety Inventory (STAI) (15-17 year-olds). The trait anxiety subscales were thus analyzed. Among younger adolescents (13-14 years of age) with myopia there was a significantly higher incidence of pathological intensification of anxiety as a constant trait. After taking into account the distribution of gender, there was a higher level of trait anxiety in the group of boys with myopia than in the control group aged 13-17 years and 13-14 years. There was also a higher level of trait anxiety detected in males than in females. Myopia may affect the level of trait anxiety among 13-14-year-olds. In both age groups of girls, a higher percentage of patients with high level of anxiety was discovered (≥7 sten), as compared to their peers without vision defects. Our results can contribute to a more accurate analysis of young teenagers' psychological problems, especially among boys diagnosed with myopia.

Development of Refractive Errors-What Can We Learn From Inherited Retinal Dystrophies?

PubMed

Hendriks, Michelle; Verhoeven, Virginie J M; Buitendijk, Gabriëlle H S; Polling, Jan Roelof; Meester-Smoor, Magda A; Hofman, Albert; Kamermans, Maarten; Ingeborgh van den Born, L; Klaver, Caroline C W

2017-10-01

It is unknown which retinal cells are involved in the retina-to-sclera signaling cascade causing myopia. As inherited retinal dystrophies (IRD) are characterized by dysfunction of a single retinal cell type and have a high risk of refractive errors, a study investigating the affected cell type, causal gene, and refractive error in IRDs may provide insight herein. Case-control study. Study Population: Total of 302 patients with IRD from 2 ophthalmogenetic centers in the Netherlands. Reference Population: Population-based Rotterdam Study-III and Erasmus Rucphen Family Study (N = 5550). Distributions and mean spherical equivalent (SE) were calculated for main affected cell type and causal gene; and risks of myopia and hyperopia were evaluated using logistic regression. Bipolar cell-related dystrophies were associated with the highest risk of SE high myopia 239.7; odds ratio (OR) mild hyperopia 263.2, both P < .0001; SE -6.86 diopters (D) (standard deviation [SD] 6.38), followed by cone-dominated dystrophies (OR high myopia 19.5, P < .0001; OR high hyperopia 10.7, P = .033; SE -3.10 D [SD 4.49]); rod dominated dystrophies (OR high myopia 10.1, P < .0001; OR high hyperopia 9.7, P = .001; SE -2.27 D [SD 4.65]), and retinal pigment epithelium (RPE)-related dystrophies (OR low myopia 2.7; P = .001; OR high hyperopia 5.8; P = .025; SE -0.10 D [SD 3.09]). Mutations in RPGR (SE -7.63 D [SD 3.31]) and CACNA1F (SE -5.33 D [SD 3.10]) coincided with the highest degree of myopia and in CABP4 (SE 4.81 D [SD 0.35]) with the highest degree of hyperopia. Refractive errors, in particular myopia, are common in IRD. The bipolar synapse and the inner and outer segments of the photoreceptor may serve as critical sites for myopia development. Copyright © 2017 Elsevier Inc. All rights reserved.

DISSECTING THE GENETICS OF HUMAN HIGH MYOPIA: A MOLECULAR BIOLOGIC APPROACH

PubMed Central

Young, Terri L

2004-01-01

ABSTRACT Purpose Despite the plethora of experimental myopia animal studies that demonstrate biochemical factor changes in various eye tissues, and limited human studies utilizing pharmacologic agents to thwart axial elongation, we have little knowledge of the basic physiology that drives myopic development. Identifying the implicated genes for myopia susceptibility will provide a fundamental molecular understanding of how myopia occurs and may lead to directed physiologic (ie, pharmacologic, gene therapy) interventions. The purpose of this proposal is to describe the results of positional candidate gene screening of selected genes within the autosomal dominant high-grade myopia-2 locus (MYP2) on chromosome 18p11.31. Methods A physical map of a contracted MYP2 interval was compiled, and gene expression studies in ocular tissues using complementary DNA library screens, microarray matches, and reverse-transcription techniques aided in prioritizing gene selection for screening. The TGIF, EMLIN-2, MLCB, and CLUL1 genes were screened in DNA samples from unrelated controls and in high-myopia affected and unaffected family members from the original seven MYP2 pedigrees. All candidate genes were screened by direct base pair sequence analysis. Results Consistent segregation of a gene sequence alteration (polymorphism) with myopia was not demonstrated in any of the seven families. Novel single nucleotide polymorphisms were found. Conclusion The positional candidate genes TGIF, EMLIN-2, MLCB, and CLUL1 are not associated with MYP2-linked high-grade myopia. Base change polymorphisms discovered with base sequence screening of these genes were submitted to an Internet database. Other genes that also map within the interval are currently undergoing mutation screening. PMID:15747770

The control effect of orthokeratology on axial length elongation in Chinese children with myopia.

PubMed

Zhu, Meng-Jun; Feng, Hao-Yan; He, Xian-Gui; Zou, Hai-Dong; Zhu, Jian-Feng

2014-11-24

To retrospectively compare axial elongation in children with different degrees of myopia wearing spectacles and undergoing ortho-k treatment. The medical records of 128 patients who were fitted with spectacles or orthokeratology (ortho-k) lenses in our clinic between 2008 and 2009 were reviewed. Ortho-k group comprised 65 subjects and 63 subjects wearing spectacles were included in the control group. Subjects were also divided into low-myopia, moderate-myopia and high-myopia groups, based on the basic spherical equivalent refractive error. Axial length periodically measured over 2-year of lens wear and changes in axial length were compared between treatment groups and between subgroups with different degrees of myopia. The control group exhibited more changes in axial length than the ortho-k group at both 12 months (0.39 ± 0.21 mm vs 0.16 ± 0.17 mm, p <0.001) and 24 months (0.70 ± 0.35 mm vs 0.34 ± 0.29 mm, p <0.001). Axial length elongation was estimated to be slower by about 51% in the ortho-k group. Similar results were found for the subgroups (49%, 59% and 46% reductions, respectively). In the group with low and moderate myopia, the annual increases in axial length were significantly different between the ortho-k and control groups during both the first ( Low myopia: 0.19 ± 0.17 mm vs 0.40 ± 0.18 mm, p = 0.001; Moderate myopia: 0.14 ± 0.18 mm vs 0.45 ± 0.22 mm, p <0.001) and second ( Low myopia: 0.18 ± 0.14 mm vs 0.32 ± 0.19 mm, p = 0.012; Moderate myopia: 0.18 ± 0.16 mm vs 0.34 ± 0.30 mm, p = 0.030) years. In the high myopia groups, significant differences were only found between the ortho-k and control groups during the first year (0.16 ± 0.18 mm vs 0.34 ± 0.22 mm, p = 0.004). The 2-year axial elongation was significantly associated with initial age (p <0.001) and treatment (p <0.001), but not with gender, initial refractive error, initial axial length, initial corneal curvature. This 2-year study indicates that ortho-k contact lens wear is effective for reducing myopia progression in children with low, moderate and high myopia.

Global trends in myopia management attitudes and strategies in clinical practice.

PubMed

Wolffsohn, James S; Calossi, Antonio; Cho, Pauline; Gifford, Kate; Jones, Lyndon; Li, Ming; Lipener, Cesar; Logan, Nicola S; Malet, Florence; Matos, Sofia; Meijome, Jose Manuel Gonzalez; Nichols, Jason J; Orr, Janis B; Santodomingo-Rubido, Jacinto; Schaefer, Tania; Thite, Nilesh; van der Worp, Eef; Zvirgzdina, Madara

2016-04-01

Myopia is a global public health issue; however, no information exists as to how potential myopia retardation strategies are being adopted globally. A self-administrated, internet-based questionnaire was distributed in six languages, through professional bodies to eye care practitioners globally. The questions examined: awareness of increasing myopia prevalence, perceived efficacy and adoption of available strategies, and reasons for not adopting specific strategies. Of the 971 respondents, concern was higher (median 9/10) in Asia than in any other continent (7/10, p<0.001) and they considered themselves more active in implementing myopia control strategies (8/10) than Australasia and Europe (7/10), with North (4/10) and South America (5/10) being least proactive (p<0.001). Orthokeratology was perceived to be the most effective method of myopia control, followed by increased time outdoors and pharmaceutical approaches, with under-correction and single vision spectacles felt to be the least effective (p<0.05). Although significant intra-regional differences existed, overall most practitioners 67.5 (±37.8)% prescribed single vision spectacles or contact lenses as the primary mode of correction for myopic patients. The main justifications for their reluctance to prescribe alternatives to single vision refractive corrections were increased cost (35.6%), inadequate information (33.3%) and the unpredictability of outcomes (28.2%). Regardless of practitioners' awareness of the efficacy of myopia control techniques, the vast majority still prescribe single vision interventions to young myopes. In view of the increasing prevalence of myopia and existing evidence for interventions to slow myopia progression, clear guidelines for myopia management need to be established. Copyright © 2016 Elsevier Ltd. All rights reserved.

Novel Myopia Genes and Pathways Identified From Syndromic Forms of Myopia

PubMed Central

Loughman, James; Wildsoet, Christine F.; Williams, Cathy; Guggenheim, Jeremy A.

2018-01-01

Purpose To test the hypothesis that genes known to cause clinical syndromes featuring myopia also harbor polymorphisms contributing to nonsyndromic refractive errors. Methods Clinical phenotypes and syndromes that have refractive errors as a recognized feature were identified using the Online Mendelian Inheritance in Man (OMIM) database. One hundred fifty-four unique causative genes were identified, of which 119 were specifically linked with myopia and 114 represented syndromic myopia (i.e., myopia and at least one other clinical feature). Myopia was the only refractive error listed for 98 genes and hyperopia and the only refractive error noted for 28 genes, with the remaining 28 genes linked to phenotypes with multiple forms of refractive error. Pathway analysis was carried out to find biological processes overrepresented within these sets of genes. Genetic variants located within 50 kb of the 119 myopia-related genes were evaluated for involvement in refractive error by analysis of summary statistics from genome-wide association studies (GWAS) conducted by the CREAM Consortium and 23andMe, using both single-marker and gene-based tests. Results Pathway analysis identified several biological processes already implicated in refractive error development through prior GWAS analyses and animal studies, including extracellular matrix remodeling, focal adhesion, and axon guidance, supporting the research hypothesis. Novel pathways also implicated in myopia development included mannosylation, glycosylation, lens development, gliogenesis, and Schwann cell differentiation. Hyperopia was found to be linked to a different pattern of biological processes, mostly related to organogenesis. Comparison with GWAS findings further confirmed that syndromic myopia genes were enriched for genetic variants that influence refractive errors in the general population. Gene-based analyses implicated 21 novel candidate myopia genes (ADAMTS18, ADAMTS2, ADAMTSL4, AGK, ALDH18A1, ASXL1, COL4A1, COL9A2, ERBB3, FBN1, GJA1, GNPTG, IFIH1, KIF11, LTBP2, OCA2, POLR3B, POMT1, PTPN11, TFAP2A, ZNF469). Conclusions Common genetic variants within or nearby genes that cause syndromic myopia are enriched for variants that cause nonsyndromic, common myopia. Analysis of syndromic forms of refractive errors can provide new insights into the etiology of myopia and additional potential targets for therapeutic interventions. PMID:29346494

Evaluation of the X-Linked High-Grade Myopia Locus (MYP1) with Cone Dysfunction and Color Vision Deficiencies

PubMed Central

Metlapally, Ravikanth; Michaelides, Michel; Bulusu, Anuradha; Li, Yi-Ju; Schwartz, Marianne; Rosenberg, Thomas; Hunt, David M.; Moore, Anthony T.; Züchner, Stephan; Rickman, Catherine Bowes; Young, Terri L.

2014-01-01

Purpose X-linked high myopia with mild cone dysfunction and color vision defects has been mapped to chromosome Xq28 (MYP1 locus). CXorf2/TEX28 is a nested, intercalated gene within the red-green opsin cone pigment gene tandem array on Xq28. The authors investigated whether TEX28 gene alterations were associated with the Xq28-linked myopia phenotype. Genomic DNA from five pedigrees (with high myopia and either protanopia or deuteranopia) that mapped to Xq28 were screened for TEX28 copy number variations (CNVs) and sequence variants. Methods To examine for CNVs, ultra-high resolution array-comparative genomic hybridization (array-CGH) assays were performed comparing the subject genomic DNA with control samples (two pairs from two pedigrees). Opsin or TEX28 gene-targeted quantitative real-time gene expression assays (comparative CT method) were performed to validate the array-CGH findings. All exons of TEX28, including intron/exon boundaries, were amplified and sequenced using standard techniques. Results Array-CGH findings revealed predicted duplications in affected patient samples. Although only three copies of TEX28 were previously reported within the opsin array, quantitative real-time analysis of the TEX28 targeted assay of affected male or carrier female individuals in these pedigrees revealed either fewer (one) or more (four or five) copies than did related and control unaffected individuals. Sequence analysis of TEX28 did not reveal any variants associated with the disease status. Conclusions CNVs have been proposed to play a role in disease inheritance and susceptibility as they affect gene dosage. TEX28 gene CNVs appear to be associated with the MYP1 X-linked myopia phenotypes. PMID:19098318

Genetic Association of Insulin-like Growth Factor-1 Polymorphisms with High-Grade Myopia in an International Family Cohort

PubMed Central

Metlapally, Ravikanth; Ki, Chang-Seok; Li, Yi-Ju; Tran-Viet, Khanh-Nhat; Abbott, Diana; Malecaze, Francois; Calvas, Patrick; Mackey, David A.; Rosenberg, Thomas; Paget, Sandrine; Guggenheim, Jeremy A.

2010-01-01

Purpose. Evidence from human myopia genetic mapping studies (MYP3 locus), modulated animal models, and observations of glycemic control in humans suggests that insulin-like growth factor (IGF)-1 plays a role in the control of eye growth. This study was conducted to determine whether IGF-1 polymorphisms are associated with myopia in a large, international dataset of Caucasian high-grade myopia pedigrees. Methods. Two hundred sixty-five multiplex families with 1391 subjects participated in the study. IGF-1 genotyping was performed with 13 selected tag single nucleotide polymorphisms (SNPs) using allelic discrimination assays. A family-based pedigree disequilibrium test (PDT) was performed to test for association. Myopia status was defined using sphere (SPH) or spherical equivalent (SE), and analyses assessed the association of (1) high-grade myopia (≤ −5.00 D), and (2) any myopia (≤ −0.50 D) with IGF-1 markers. Results were declared significant at P ≤ 0.0038 after Bonferroni correction. Q values that take into account multiple testing were also obtained. Results. In all, three SNPs—rs10860860, rs2946834, and rs6214—were present at P < 0.05. SNP rs6214 showed positive association with both the high-grade– and any-myopia groups (P = 2 × 10−3 and P = 2 × 10−3, respectively) after correction for multiple testing. Conclusions. The study supports a genetic association between IGF-1 and high-grade myopia. These findings are in line with recent evidence in an experimental myopia model showing that IGF-1 promotes ocular growth and axial myopia. IGF-1 may be a myopia candidate gene for further investigation. PMID:20435602

Environmental Factors and Myopia: Paradoxes and Prospects for Prevention.

PubMed

Rose, Kathryn Ailsa; French, Amanda Nicole; Morgan, Ian George

The prevalence of myopia in developed countries in East and Southeast Asia has increased to more than 80% in children completing schooling, whereas that of high myopia has increased to 10%-20%. This poses significant challenges for correction of refractive errors and the management of pathological high myopia. Prevention is therefore an important priority. Myopia is etiologically heterogeneous, with a low level of myopia of clearly genetic origins that appears without exposure to risk factors. The big increases have occurred in school myopia, driven by increasing educational pressures in combination with limited amounts of time spent outdoors. The rise in prevalence of high myopia has an unusual pattern of development, with increases in prevalence first appearing at approximately age 11. This pattern suggests that the increasing prevalence of high myopia is because of progression of myopia in children who became myopic at approximately age 6 or 7 because age-specific progression rates typical of East Asia will take these children to the threshold for high myopia in 5 to 6 years. This high myopia seems to be acquired, having an association with educational parameters, whereas high myopia in previous generations tended to be genetic in origin. Increased time outdoors can counter the effects of increased nearwork and reduce the impact of parental myopia, reducing the onset of myopia, and this approach has been validated in 3 randomized controlled trials. Other proposed risk factors need further work to demonstrate that they are independent and can be modified to reduce the onset of myopia.

Retinal Microvascular Network and Microcirculation Assessments in High Myopia.

PubMed

Li, Min; Yang, Ye; Jiang, Hong; Gregori, Giovanni; Roisman, Luiz; Zheng, Fang; Ke, Bilian; Qu, Dongyi; Wang, Jianhua

2017-02-01

To investigate the changes of the retinal microvascular network and microcirculation in high myopia. A cross-sectional, matched, comparative clinical study. Twenty eyes of 20 subjects with nonpathological high myopia (28 ± 5 years of age) with a refractive error of -6.31 ± 1.23 D (mean ± SD) and 20 eyes of 20 age- and sex-matched control subjects (30 ± 6 years of age) with a refractive error of -1.40 ± 1.00 D were recruited. Optical coherence tomography angiography (OCTA) was used to image the retinal microvascular network, which was later quantified by fractal analysis (box counting [D box ], representing vessel density) in both superficial and deep vascular plexuses. The Retinal Function Imager was used to image the retinal microvessel blood flow velocity (BFV). The BFV and microvascular density in the myopia group were corrected for ocular magnification using Bennett's formula. The density of both superficial and deep microvascular plexuses was significantly decreased in the myopia group in comparison to the controls (P < .05). The decrease of the microvessel density of the annular zone (0.6-2.5 mm), measured as D box , was 2.1% and 2.9% in the superficial and deep vascular plexuses, respectively. Microvessel density reached a plateau from 0.5 mm to 1.25 mm from the fovea in both groups, but that in the myopic group was about 3% lower than the control group. No significant differences were detected between the groups in retinal microvascular BFV in either arterioles or venules (P > .05). Microvascular densities in both superficial (r = -0.45, P = .047) and deep (r = -0.54, P = .01) vascular plexuses were negatively correlated with the axial lengths in the myopic eye. No correlations were observed between BFV and vessel density (P > .05). Retinal microvascular decrease was observed in the high myopia subjects, whereas the retinal microvessel BFV remained unchanged. The retinal microvascular network alteration may be attributed to ocular elongation that occurs with the progression of myopia. The novel quantitative analyses of the retinal microvasculature may help to characterize the underlying pathophysiology of myopia and enable early detection and prevention of myopic retinopathy. Copyright © 2016 Elsevier Inc. All rights reserved.

[Role of cerebral hemodynamics in the mechanism of development of acquired myopia in schoolchildren].

PubMed

Iastrebtseva, T A; Demidova, T E; Polikarpova, V E

2008-01-01

Rheoencephalography was used to study cerebral venous circulation in 199 schoolchildren aged 12-15 years who had emmetropia, pseudomyopia, and myopia. Tonometry was carried out in 39 persons. Cerebral venous hemodynamic dysfunction was more frequently encountered in schoolchildren with myopia than in those with emmetropia. Intraocular pressure was significantly higher only in schoolchildren with high myopia than in the controls.

5-hydroxytryptamine level and 5-HT2A receptor mRNA expression in the guinea pigs eyes with spectacle lens-induced myopia

PubMed Central

Yang, Ji-Wen; Xu, Yan-Chun; Sun, Lin; Tian, Xiao-Dan

2010-01-01

AIM To investigate 5-hydroxytryptamine (5-HT) function and 5-HT receptor 2A (5-HT2A) mRNA expression in the formation of lens-induced myopia (LIM). METHODS Lens-induced myopia construction method was applied to generate myopia on guinea pig right eye (LIM eye). RESULTS LIM eyes formed significant myopia with longer axial length. 5-HT level in retina, choroids and sclera from LIM eyes was significantly higher than that in control group. 5-HT2A mRNA expression was also significantly up-regulated. CONCLUSION Refraction lens could induce myopia in guinea pig and 5-HT may play an important role in the formation of myopia by binding with 5-HT2A receptor. PMID:22553578

Consistent comparison of angle Kappa adjustment between Oculyzer and Topolyzer Vario topography guided LASIK for myopia by EX500 excimer laser.

PubMed

Sun, Ming-Shen; Zhang, Li; Guo, Ning; Song, Yan-Zheng; Zhang, Feng-Ju

2018-01-01

To evaluate and compare the uniformity of angle Kappa adjustment between Oculyzer and Topolyzer Vario topography guided ablation of laser in situ keratomileusis (LASIK) by EX500 excimer laser for myopia. Totally 145 cases (290 consecutive eyes )with myopia received LASIK with a target of emmetropia. The ablation for 86 cases (172 eyes) was guided manually based on Oculyzer topography (study group), while the ablation for 59 cases (118 eyes) was guided automatically by Topolyzer Vario topography (control group). Measurement of adjustment values included data respectively in horizontal and vertical direction of cornea. Horizontally, synclastic adjustment between manually actual values (dx manu ) and Oculyzer topography guided data (dx ocu ) accounts 35.5% in study group, with mean dx manu /dx ocu of 0.78±0.48; while in control group, synclastic adjustment between automatically actual values (dx auto ) and Oculyzer topography data (dx ocu ) accounts 54.2%, with mean dx auto /dx ocu of 0.79±0.66. Vertically, synclastic adjustment between dy manu and dy ocu accounts 55.2% in study group, with mean dy manu /dy ocu of 0.61±0.42; while in control group, synclastic adjustment between dy auto and dy ocu accounts 66.1%, with mean dy auto /dy ocu of 0.66±0.65. There was no statistically significant difference in ratio of actual values/Oculyzer topography guided data in horizontal and vertical direction between two groups ( P =0.951, 0.621). There is high consistency in angle Kappa adjustment guided manually by Oculyzer and guided automatically by Topolyzer Vario topography during corneal refractive surgery by WaveLight EX500 excimer laser.

Myopia and/or longer axial length are protective against diabetic retinopathy: a meta-analysis.

PubMed

Fu, Yu; Geng, Dengfeng; Liu, Hua; Che, Huixin

2016-06-01

To evaluate the current evidence of the relationship between myopia, together with its structural and refractive component, and diabetic retinopathy (DR) risk. A systematic search was performed up to April, 2015. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were calculated employing random-effects models. Three models were used to assess the association between myopia and risk of DR: axial length (AL) (per millimetre increase) and DR; myopia (myopia versus non-myopia) and DR; refractive error (RE) (per D decrease) and DR. Publication bias of the literature was evaluated using Begg's funnel plots and Egger's test. A total of 11 studies that met the predefined criteria were included in this meta-analysis. Overall, longer AL (per millimetre increase) was associa-ted with a significantly decreased risk of DR (combined OR, 0.75; 95% CI, 0.65-0.86; p < 0.001); myopic eyes (myopia versus non-myopia) showed a lower risk of DR (combined OR, 0.70; 95% CI, 0.58-0.85; p < 0.001). A greater degree of myopic RE (per D decrease) also revealed a significantly decreased risk of DR (combined OR, 0.89; 95% CI, 0.85-0.93; p < 0.001). The sensitivity analyses and cumulative meta-analysis showed similar results. No publication bias was detected in any of the three models. This meta-analysis suggests that both myopic refraction and longer AL are associated with a lower risk of DR. Further studies are needed to determine exact mechanisms underpinning the protective effect of myopia against DR. © 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Role of Educational Exposure in the Association Between Myopia and Birth Order.

PubMed

Guggenheim, Jeremy A; Williams, Cathy

2015-12-01

Visual impairment due to myopia is an important public health issue. A prior analysis of population-based cohorts aged 15 to 22 years recruited from the United Kingdom and Israel suggested myopia and high myopia were approximately 10% more common in first-born compared with later-born children. To examine whether myopia was associated with birth order in an earlier generation than studied previously and, if so, whether the association was attenuated after adjusting for education exposure, as predicted by the hypothesis that the education of children with later birth orders is less intense. Cross-sectional study of UK Biobank participants recruited from 2006 to 2010. Analysis was restricted to participants aged 40 to 69 years who had a vision assessment, self-reported white ethnicity, and no history of eye disorders (N = 89,120). Myopia and high myopia were defined as autorefraction of -0.75 diopters (D) or less and -6.00 D or less, respectively. Birth order and information on potential confounders including highest educational qualification ascertained using a structured questionnaire. Odds ratios (ORs) for myopia and high myopia by birth order, using logistic regression and adjusting for age and sex (model 1) or age, sex, and highest educational qualification (model 2). In model 1 (no adjustment for education), birth order was associated with both myopia and high myopia (eg, comparing first- vs second-born individuals; OR, 1.12; 95% CI, 1.08-1.16; P = 1.40E-11 and OR, 1.21; 95% CI, 1.11-1.30; P = 3.60E-06 for myopia and high myopia, respectively). The risk for myopia became progressively lower for later birth orders, suggesting a dose response. In model 2 (after adjusting for education), the effect sizes were attenuated by approximately 25% (OR, 1.09; 95% CI, 1.05-1.12; P = 1.30E-06 and OR, 1.15; 95% CI, 1.06-1.25; P = 4.60E-04 for myopia and high myopia, respectively) and the apparent dose response was abolished. These data suggest that the association between birth order and myopia is not due to a new environmental pressure in the last 30 to 40 years. The attenuated effect size after adjusting for educational exposure supports a role for reduced parental investment in education of children with later birth orders in their relative protection from myopia.

Laser-Assisted Subepithelial Keratectomy versus Laser In Situ Keratomileusis in Myopia: A Systematic Review and Meta-Analysis

PubMed Central

Zhao, Li-Quan; Zhu, Huang; Li, Liang-Mao

2014-01-01

This systematic review was to compare the clinical outcomes between laser-assisted subepithelial keratectomy (LASEK) and laser in situ keratomileusis (LASIK) for myopia. Primary parameters included mean manifest refraction spherical equivalent (MRSE), MRSE within ±0.50 diopters, uncorrected visual acuity (UCVA) ≥20/20, and loss of ≥1 line of best-corrected visual acuity (BCVA). Secondary parameters included flap complications and corneal haze. Twelve clinical controlled trials were identified and used for comparing LASEK (780 eyes) to LASIK (915 eyes). There were no significant differences in visual and refractive outcomes between the two surgeries for low to moderate myopia. The incidence of loss of ≥1 line of BCVA was significantly higher in moderate to high myopia treated by LASEK than LASIK in the mid-term and long-term followup. The efficacy (MRSE and UCVA) of LASEK appeared to be a significant worsening trend in the long-term followup. Corneal haze was more severe in moderate to high myopia treated by LASEK than LASIK in the mid-term and long-term followup. The flap-related complications still occurred in LASIK, but the incidence was not significantly higher than that in LASEK. LASEK and LASIK were safe and effective for low to moderate myopia. The advantage of LASEK was the absence of flap-related complications, and such procedure complication may occur in LASIK and affect the visual results. The increased incidence of stromal haze and regression in LASEK significantly affected the visual and refractive results for high myopia. PMID:24977054

Photorefractive keratectomy (PRK) versus laser-assisted in-situ keratomileusis (LASIK) for myopia.

PubMed

Shortt, A J; Allan, B D S

2006-04-19

Myopia (also known as short-sightedness or near-sightedness) is an ocular condition in which the refractive power of the eye is greater than is required, resulting in light from distant objects being focused in front of the retina instead of directly on it. The two most commonly used surgical techniques to permanently correct myopia are photorefractive keratectomy (PRK) and laser-assisted in-situ keratomileusis (LASIK). The aim of this review was to compare the effectiveness and safety of PRK and LASIK for correction of myopia. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (2005, Issue 3), MEDLINE (1966 to September 2005), EMBASE (1980 to September 2005) and LILACs (1982 to 3 November 2005). We also searched the reference lists of the studies and the Science Citation Index. We included randomised controlled trials comparing PRK and LASIK for correction of any degree of myopia. We also included data on adverse events from prospective multicentre consecutive case series in the Food and Drugs Administration (FDA) trials database (http//www.fda.gov/cdrh/LASIK/lasers.htm). Two authors independently assessed trial quality and extracted data. Data were summarised using odds ratio and mean difference. Odds ratios were combined using a random-effects model after testing for heterogeneity. This review included six randomised controlled trials involving a total of 417 eyes, of which 201 were treated with PRK and 216 with LASIK. We found that although LASIK gives a faster visual recovery than PRK, the effectiveness of these two procedures is comparable. We found some evidence that LASIK may be less likely than PRK to result in loss of best spectacle-corrected visual acuity. LASIK gives a faster visual recovery than PRK but the effectiveness of these two procedures is comparable. Further trials using contemporary techniques are required to determine whether LASIK and PRK are equally safe.

Evaluation the COL9A2 gene with high myopia

NASA Astrophysics Data System (ADS)

Zhang, Dingding; Huang, Maomin

2017-11-01

This paper investigates the association of the COL9A2 gene between high myopia and normal controls in the Han Chinese population. It shows that the frameshift mutation (D281fs) in the COL9A2 gene is not associated with high myopia in the Han Chinese population, and the two novel variants(c.143G＞C and c.884G＞A) may contribute to the development of high myopia.

Excimer Laser Versus Phakic Intraocular Lenses for Myopia and Astigmatism: A Meta-Analysis of Randomized Controlled Trials.

PubMed

Chen, Haiting; Liu, Yu; Niu, Guangzeng; Ma, Jingxue

2018-05-01

Meta-analysis of randomized controlled trials (RCTs) which compared excimer laser refractive surgery and phakic intraocular lenses (PIOLs) for the treatment of myopia and astigmatism. An electronic literature search was performed using the PubMed, EBSCO, CNKI, and Cochrane Library database to identify prospective RCTs which compared excimer laser refractive surgery and PIOL with a follow-up time of at least 12 months. Efficacy, accuracy, safety outcomes, and complications were analyzed by standardized mean difference, risk ratio, and the pooled estimates according to a fixed effect model or random effect model. This review included 5 RCTs with a sum of 405 eyes. The range of myopia was 6.0 to 20.0 D with up to 4.0 D of astigmatism. The PIOL group was more likely to achieve a spherical equivalence within±1.0 D of target refraction at 12 months postoperatively (P=0.009), and was less likely to lose one or more lines of best spectacle corrected visual acuity than the LASER group (P=0.002). On the whole, there is no significant difference in efficacy and complications between the two kinds of surgeries. This meta-analysis indicated that PIOLs were safer and more accurate within 12 months of follow-up compared with excimer laser surgical for refractive errors.

Prevalence and risk factors for myopia in older adult east Chinese population.

PubMed

Xu, Cailian; Pan, Chenwei; Zhao, Chunhua; Bi, Mingchao; Ma, Qinghua; Cheng, Jianhui; Song, E

2017-10-13

To determine the prevalence and associated factors for myopia and high myopia among older population in a rural community in Eastern China. A community-based, cross-sectional survey was conducted in the Weitang town located in Suzhou, an urban metropolis in East China. A total of 5613 Chinese residents aged 60 years and older were invited to complete a questionnaire and participated in a detailed eye examination,including measurements of visual acuity and refractive error using autorefraction and subjective refraction. Myopia and high myopia was defined as SE < -0.5 diopters (D) and < -5.0 D, respectively. Among the 5613 participating individuals, 4795 (85.4%) complete refraction data of phakic right eye was included for analysis. The age-adjusted prevalence was 21.1% (95% confidence interval [CI], 19.9-22.2) for myopia and 2.5% (95% CI, 2.1-2.9) for high myopia. The prevalence of myopia tended to increase significantly with age(p < 0.001),and women had a higher rate of myopia than men (p < 0.001). According to multivariate logistic regression analysis, adults who were older (odds ration[OR]:1.05; 95% CI:1.04-1.07), spent more time for sleeping at night (OR:1.12;95% CI: 1.06-1.18),or had cataract (OR:1.60;95% CI:1.36-1.88) and family history of myopia (OR:1.47;95% CI:1.23-1.77), are more susceptible to myopia (p < 0.001). People who had older age, family history, cataract and specially longer night-time sleep duration, would have a higher risk of myopia. Myopia and high myopia among rural old adult population in Eastern China presents common. The current literature unanticipated suggests that there was a positive significant association between prevalence of myopia and night-time sleep duration among adult. Our data provide some evidence of this relationship and highlight the need for larger studies to further investigate this relationship longitudinally and explore mechanism therein.

Myopia: the importance of seeing fine detail.

PubMed

Schaeffel, Frank

2006-04-04

Eye growth and myopia development are controlled by the retina. What properties of the image tell the retina how the eye should grow? A recent study has shown that, in chickens, fine details are necessary to prevent the development of myopia. Should we carefully avoid any defocus to avoid becoming myopic?

Myopia Development Among Young Schoolchildren: The Myopia Investigation Study in Taipei.

PubMed

Tsai, Der-Chong; Fang, Shao-You; Huang, Nicole; Hsu, Chih-Chien; Chen, Shing-Yi; Chiu, Allen Wen-Hsiang; Liu, Catherine Jui-Ling

2016-12-01

To investigate the annual incidence of myopia and associated factors among young schoolchildren in Taipei City. The Myopia Investigation Study in Taipei was a citywide, population-based cohort study. During the fall 2013 semester (baseline), a total of 11,590 grade 2 schoolchildren completed ocular examination and were included for further analysis. A parent-completed questionnaire was administered to collect data on risk factors for myopia development. Follow-up visits were arranged biannually over 3 years. The first-year results are reported here. Schoolchildren who were emmetropic/hyperopic at baseline and had myopia (spherical equivalent ≤ -0.5 diopters) in either eye at follow-up were identified as having incident myopia. Among 7376 baseline nonmyopic participants, 6794 (92.1%) were examined during the first-year follow-up, and 1856 (25.2%) with incident myopia were identified. The incidence density of myopia was 31.7 (95% confidence interval [CI]: 30.6-32.8) per 100 person-years. Cox hazard proportional regression analysis revealed that participants who were emmetropic at baseline (hazards ratio [HR]: 19.37; 95% CI: 4.84-77.57), who had two myopic parents (HR: 1.21; 95% CI: 1.04-1.42), and who spent ≥5 hours every week on after-school tutoring programs (HR: 1.12; 95% CI: 1.02-1.22) had greater risk for incident myopia. By contrast, protective factors included suburban area of residence (HR: 0.91; 95% CI: 0.83-1.00) and spending ≥30 minutes outdoors after school every weekday (HR: 0.90; 95% CI: 0.82-0.99). This study provides population-based data on the annual incidence of myopia among Taiwanese schoolchildren, and found that baseline refractive status, parental myopia, area of residence, time outdoors after school on weekdays, and time spent on after-school tutoring programs are associated with risk of new-onset myopia.

Unique Variants in OPN1LW Cause Both Syndromic and Nonsyndromic X-Linked High Myopia Mapped to MYP1.

PubMed

Li, Jiali; Gao, Bei; Guan, Liping; Xiao, Xueshan; Zhang, Jianguo; Li, Shiqiang; Jiang, Hui; Jia, Xiaoyun; Yang, Jianhua; Guo, Xiangming; Yin, Ye; Wang, Jun; Zhang, Qingjiong

2015-06-01

MYP1 is a locus for X-linked syndromic and nonsyndromic high myopia. Recently, unique haplotypes in OPN1LW were found to be responsible for X-linked syndromic high myopia mapped to MYP1. The current study is to test if such variants in OPN1LW are also responsible for X-linked nonsyndromic high myopia mapped to MYP1. The proband of the family previously mapped to MYP1 was initially analyzed using whole-exome sequencing and whole-genome sequencing. Additional probands with early-onset high myopia were analyzed using whole-exome sequencing. Variants in OPN1LW were selected and confirmed by Sanger sequencing. Long-range and second PCR were used to determine the haplotype and the first gene of the red-green gene array. Candidate variants were further validated in family members and controls. The unique LVAVA haplotype in OPN1LW was detected in the family with X-linked nonsyndromic high myopia mapped to MYP1. In addition, this haplotype and a novel frameshift mutation (c.617_620dup, p.Phe208Argfs*51) in OPN1LW were detected in two other families with X-linked high myopia. The unique haplotype cosegregated with high myopia in the two families, with a maximum LOD score of 3.34 and 2.31 at θ = 0. OPN1LW with the variants in these families was the first gene in the red-green gene array and was not present in 247 male controls. Reevaluation of the clinical data in both families with the unique haplotype suggested nonsyndromic high myopia. Our study confirms the findings that unique variants in OPN1LW are responsible for both syndromic and nonsyndromic X-linked high myopia mapped to MYP1.

Linkage analysis of quantitative refraction and refractive errors in the Beaver Dam Eye Study.

PubMed

Klein, Alison P; Duggal, Priya; Lee, Kristine E; Cheng, Ching-Yu; Klein, Ronald; Bailey-Wilson, Joan E; Klein, Barbara E K

2011-07-13

Refraction, as measured by spherical equivalent, is the need for an external lens to focus images on the retina. While genetic factors play an important role in the development of refractive errors, few susceptibility genes have been identified. However, several regions of linkage have been reported for myopia (2q, 4q, 7q, 12q, 17q, 18p, 22q, and Xq) and for quantitative refraction (1p, 3q, 4q, 7p, 8p, and 11p). To replicate previously identified linkage peaks and to identify novel loci that influence quantitative refraction and refractive errors, linkage analysis of spherical equivalent, myopia, and hyperopia in the Beaver Dam Eye Study was performed. Nonparametric, sibling-pair, genome-wide linkage analyses of refraction (spherical equivalent adjusted for age, education, and nuclear sclerosis), myopia and hyperopia in 834 sibling pairs within 486 extended pedigrees were performed. Suggestive evidence of linkage was found for hyperopia on chromosome 3, region q26 (empiric P = 5.34 × 10(-4)), a region that had shown significant genome-wide evidence of linkage to refraction and some evidence of linkage to hyperopia. In addition, the analysis replicated previously reported genome-wide significant linkages to 22q11 of adjusted refraction and myopia (empiric P = 4.43 × 10(-3) and 1.48 × 10(-3), respectively) and to 7p15 of refraction (empiric P = 9.43 × 10(-4)). Evidence was also found of linkage to refraction on 7q36 (empiric P = 2.32 × 10(-3)), a region previously linked to high myopia. The findings provide further evidence that genes controlling refractive errors are located on 3q26, 7p15, 7p36, and 22q11.

Aripiprazole-induced transient myopia: A rare entity.

PubMed

Praveen Kumar, K V; Chiranjeevi, P; Alam, Md Shahid

2018-01-01

Aripiprazole is a new drug for the treatment of adults with schizophrenia. Ocular side effects of aripiprazole are very rare. Review of literature revealed few cases of aripiprazole-induced myopia. We report a rare case of aripiprazole-induced transient myopia. A 22-year-old female patient presented to the department of psychiatry with worsening of symptoms of schizophrenia and was started on aripiprazole. She presented with complaints of blurring of vision in both eyes for 1 week which started on the 3rd day following the use of aripiprazole. Anterior segment examination revealed a shallow anterior chamber and narrow angles. Intraocular pressure was normal. A diagnosis of aripiprazole-induced acute myopia was made and the treating psychiatrist was advised to stop the medication. At 2-week follow-up, the unaided visual acuity improved to 20/20 in both the eyes. Ophthalmologists should be aware of the myopic shift that may occur as an ocular side effect with aripiprazole.

Role of Educational Exposure in the Association between Myopia and Birth Order

PubMed Central

Guggenheim, Jeremy A.; Williams, Cathy

2015-01-01

Importance Visual impairment due to myopia is an important public health issue. Recent analysis of population-based cohorts aged 15-22 years-old recruited from the UK and Israel, suggested myopia and high myopia were ~10% more common in first-born compared to later-born children. Objectives To examine whether myopia was associated with birth order in an earlier generation than studied previously, and if so, whether the association was attenuated after adjusting for education exposure, as predicted by the hypothesis that the education of children with later birth orders is less intense. Design, setting, and participants Cross-sectional study of UK Biobank participants recruited from 2006 to 2010. Analysis was restricted to participants 40-69 years-old who had a vision assessment, self-reported ethnicity ‘White’, and no history of eye disorders (N=89,120). Myopia and high myopia were defined as autorefraction <= −0.75D and <= −6.00D, respectively. Exposures Birth order and information on potential confounders including highest educational qualification ascertained using a structured questionnaire. Main Outcome Measures Odds ratio (OR) for myopia and high myopia by birth order, using logistic regression adjusting for age and sex (Model 1), or age, sex, and highest educational qualification (Model 2). Results Model 1 (no adjustment for education): Birth order was associated with both myopia and high myopia, e.g. comparing first versus second born individuals, OR = 1.12 (95% CI 1.08 to 1.16, P=1.4E-11) and OR = 1.21 (95% CI 1.11 to 1.30, P=3.6E-6) for myopia and high myopia, respectively. The risk of myopia became progressively lower for later-birth orders suggesting a dose-response. Model 2 (after adjusting for education): The effect sizes were attenuated by approximately 25%: OR = 1.09 (95% CI 1.05 to 1.12, P=1.3E-6) and OR = 1.15 (95% CI 1.06 to 1.25, P=4.6E-4) for myopia and high myopia, respectively, and the apparent dose-response was abolished. Conclusions and Relevance These data suggest that the association between birth order and myopia is not due to a new environmental pressure in the last 30-40 years. The attenuated effect size after adjusting for educational exposure supports a role for reduced parental investment in education of children with later birth orders in their relative protection from myopia. PMID:26448589

Housing type and myopia: the mediating role of parental myopia.

PubMed

Wu, Xiaoyan; Gao, Guopeng; Jin, Juxiang; Hua, Wenjuan; Tao, Liming; Xu, Shaojun; Tao, Fangbiao

2016-08-31

Myopia has become a significant global public health concern, and is highly prevalent worldwide especially in Asian countries. It is associated with genetic factors as well as socioeconomic status; however, the underlying cause for school myopia has not been established. This study evaluates the impact of living environment on school myopia in Chinese school-aged children. A large cross-sectional sample of area- and ethnicity-matched school children; a total of 43, 771 children from 12 cities participated in this study. The presence of myopia was self-reported and potential risk factors were determined by questionnaires. The self-reported prevalence of myopia in Chinese children was 31.8 % (n = 13, 928). In multiple logistic regression analysis, higer risk of myopia among school-aged children was significantly positively associated with both parental myopia (OR = 3.57; 95 % CI: 3.26-3.90), living in 1-3 floor (OR = 1.28; 95 % CI: 2.57-3.15), 4-6 floor (OR = 1.84; 95 % CI: 1.73-1.95) and 7 floor or more (OR = 2.02; 95 % CI: 1.88-2.16). Particularly, housing type was independently associated with myopia after stratified by parental myopia. An increasing prevalence of myopia was found with increasing floor of housing type in each outdoor time group. Housing type was independently associated with myopia, after stratified by parental myopia. Flat room, lower living floor and more outdoor time may be protective factors for myopia among school-aged children in mainland China.

cAMP Level Modulates Scleral Collagen Remodeling, a Critical Step in the Development of Myopia

PubMed Central

Liu, Shufeng; Fang, Fang; Lu, Runxia; Lu, Chanyi; Zheng, Min; An, Jianhong; Xu, Hongjia; Zhao, Fuxin; Chen, Jiang-fan; Qu, Jia; Zhou, Xiangtian

2013-01-01

The development of myopia is associated with decreased ocular scleral collagen synthesis in humans and animal models. Collagen synthesis is, in part, under the influence of cyclic adenosine monophosphate (cAMP). We investigated the associations between cAMP, myopia development in guinea pigs, and collagen synthesis by human scleral fibroblasts (HSFs). Form-deprived myopia (FDM) was induced by unilateral masking of guinea pig eyes. Scleral cAMP levels increased selectively in the FDM eyes and returned to normal levels after unmasking and recovery. Unilateral subconjunctival treatment with the adenylyl cyclase (AC) activator forskolin resulted in a myopic shift accompanied by reduced collagen mRNA levels, but it did not affect retinal electroretinograms. The AC inhibitor SQ22536 attenuated the progression of FDM. Moreover, forskolin inhibited collagen mRNA levels and collagen secretion by HSFs. The inhibition was reversed by SQ22536. These results demonstrate a critical role of cAMP in control of myopia development. Selective regulation of cAMP to control scleral collagen synthesis may be a novel therapeutic strategy for preventing and treating myopia. PMID:23951163

Correction of Refractive Errors in Rhesus Macaques (Macaca mulatta) Involved in Visual Research

PubMed Central

Mitchell, Jude F; Boisvert, Chantal J; Reuter, Jon D; Reynolds, John H; Leblanc, Mathias

2014-01-01

Macaques are the most common animal model for studies in vision research, and due to their high value as research subjects, often continue to participate in studies well into old age. As is true in humans, visual acuity in macaques is susceptible to refractive errors. Here we report a case study in which an aged macaque demonstrated clear impairment in visual acuity according to performance on a demanding behavioral task. Refraction demonstrated bilateral myopia that significantly affected behavioral and visual tasks. Using corrective lenses, we were able to restore visual acuity. After correction of myopia, the macaque's performance on behavioral tasks was comparable to that of a healthy control. We screened 20 other male macaques to assess the incidence of refractive errors and ocular pathologies in a larger population. Hyperopia was the most frequent ametropia but was mild in all cases. A second macaque had mild myopia and astigmatism in one eye. There were no other pathologies observed on ocular examination. We developed a simple behavioral task that visual research laboratories could use to test visual acuity in macaques. The test was reliable and easily learned by the animals in 1 d. This case study stresses the importance of screening macaques involved in visual science for refractive errors and ocular pathologies to ensure the quality of research; we also provide simple methodology for screening visual acuity in these animals. PMID:25427343

Correction of refractive errors in rhesus macaques (Macaca mulatta) involved in visual research.

PubMed

Mitchell, Jude F; Boisvert, Chantal J; Reuter, Jon D; Reynolds, John H; Leblanc, Mathias

2014-08-01

Macaques are the most common animal model for studies in vision research, and due to their high value as research subjects, often continue to participate in studies well into old age. As is true in humans, visual acuity in macaques is susceptible to refractive errors. Here we report a case study in which an aged macaque demonstrated clear impairment in visual acuity according to performance on a demanding behavioral task. Refraction demonstrated bilateral myopia that significantly affected behavioral and visual tasks. Using corrective lenses, we were able to restore visual acuity. After correction of myopia, the macaque's performance on behavioral tasks was comparable to that of a healthy control. We screened 20 other male macaques to assess the incidence of refractive errors and ocular pathologies in a larger population. Hyperopia was the most frequent ametropia but was mild in all cases. A second macaque had mild myopia and astigmatism in one eye. There were no other pathologies observed on ocular examination. We developed a simple behavioral task that visual research laboratories could use to test visual acuity in macaques. The test was reliable and easily learned by the animals in 1 d. This case study stresses the importance of screening macaques involved in visual science for refractive errors and ocular pathologies to ensure the quality of research; we also provide simple methodology for screening visual acuity in these animals.

Effects of Constant Flickering Light on Refractive Status, 5-HT and 5-HT2A Receptor in Guinea Pigs.

PubMed

Li, Bing; Luo, Xiumei; Li, Tao; Zheng, Changyue; Ji, Shunmei; Ma, Yuanyuan; Zhang, Shuangshuang; Zhou, Xiaodong

2016-01-01

To investigate the effects of constant flickering light on refractive development, the role of serotonin (i.e.5-hydroxytryptamine, 5-HT)and 5-HT2A receptor in myopia induced by flickering light in guinea pigs. Forty-five guinea pigs were randomly divided into three groups: control, form deprivation myopia (FDM) and flickering light induced myopia (FLM) groups(n = 15 for each group). The right eyes of the FDM group were covered with semitransparent hemispherical plastic shells serving as eye diffusers. Guinea pigs in FLM group were raised with illumination of a duty cycle of 50% at a flash frequency of 0.5Hz. The refractive status, axial length (AL), corneal radius of curvature(CRC) were measured by streak retinoscope, A-scan ultrasonography and keratometer, respectively. Ultramicroscopy images were taken by electron microscopy. The concentrations of 5-HTin the retina, vitreous body and retinal pigment epithelium (RPE) were assessed by high performance liquid chromatography, the retinal 5-HT2A receptor expression was evaluated by immunohistofluorescence and western blot. The refraction of FDM and FLM eyes became myopic from some time point (the 4th week and the 6th week, respectively) in the course of the experiment, which was indicated by significantly decreased refraction and longer AL when compared with the controls (p<0.05). The concentrations of 5-HT in the retina, vitreous body and RPE of FDM and FLM eyes were significantly increased in comparison with those of control eyes (both p<0.05). Similar to FDM eyes, the expression of retinal 5-HT2A receptor in FLM eyes was significantly up-regulated compared to that of control eyes (both p<0.05). Western blot analysis showed that retinal 5-HT2A receptor level elevated less in the FLM eyes than that in the FDM eyes. Moreover, the levels of norepinephrine and epinephrine in FDM and FLM groups generally decreased when compared with control groups (all p<0.05). Constant flickering light could cause progressive myopia in guinea pigs. 5-HT and 5-HT2A receptor increased both in form deprivation myopia and flickering light induced myopia, indicating that 5-HT possibly involved in myopic development via binding to5-HT2A receptor.

Effects of Constant Flickering Light on Refractive Status, 5-HT and 5-HT2A Receptor in Guinea Pigs

PubMed Central

Li, Tao; Zheng, Changyue; Ji, Shunmei; Ma, Yuanyuan; Zhang, Shuangshuang; Zhou, Xiaodong

2016-01-01

Purpose To investigate the effects of constant flickering light on refractive development, the role of serotonin (i.e.5-hydroxytryptamine, 5-HT)and 5-HT2A receptor in myopia induced by flickering light in guinea pigs. Methods Forty-five guinea pigs were randomly divided into three groups: control, form deprivation myopia (FDM) and flickering light induced myopia (FLM) groups(n = 15 for each group). The right eyes of the FDM group were covered with semitransparent hemispherical plastic shells serving as eye diffusers. Guinea pigs in FLM group were raised with illumination of a duty cycle of 50% at a flash frequency of 0.5Hz. The refractive status, axial length (AL), corneal radius of curvature(CRC) were measured by streak retinoscope, A-scan ultrasonography and keratometer, respectively. Ultramicroscopy images were taken by electron microscopy. The concentrations of 5-HTin the retina, vitreous body and retinal pigment epithelium (RPE) were assessed by high performance liquid chromatography, the retinal 5-HT2A receptor expression was evaluated by immunohistofluorescence and western blot. Results The refraction of FDM and FLM eyes became myopic from some time point (the 4th week and the 6th week, respectively) in the course of the experiment, which was indicated by significantly decreased refraction and longer AL when compared with the controls (p<0.05). The concentrations of 5-HT in the retina, vitreous body and RPE of FDM and FLM eyes were significantly increased in comparison with those of control eyes (both p<0.05). Similar to FDM eyes, the expression of retinal 5-HT2A receptor in FLM eyes was significantly up-regulated compared to that of control eyes (both p<0.05). Western blot analysis showed that retinal 5-HT2A receptor level elevated less in the FLM eyes than that in the FDM eyes. Moreover, the levels of norepinephrine and epinephrine in FDM and FLM groups generally decreased when compared with control groups (all p<0.05). Conclusions Constant flickering light could cause progressive myopia in guinea pigs. 5-HT and 5-HT2A receptor increased both in form deprivation myopia and flickering light induced myopia, indicating that 5-HT possibly involved in myopic development via binding to5-HT2A receptor. PMID:27959948

Genome-Wide Analysis Points to Roles for Extracellular Matrix Remodeling, the Visual Cycle, and Neuronal Development in Myopia

PubMed Central

Kiefer, Amy K.; Tung, Joyce Y.; Do, Chuong B.; Hinds, David A.; Mountain, Joanna L.; Francke, Uta; Eriksson, Nicholas

2013-01-01

Myopia, or nearsightedness, is the most common eye disorder, resulting primarily from excess elongation of the eye. The etiology of myopia, although known to be complex, is poorly understood. Here we report the largest ever genome-wide association study (45,771 participants) on myopia in Europeans. We performed a survival analysis on age of myopia onset and identified 22 significant associations (), two of which are replications of earlier associations with refractive error. Ten of the 20 novel associations identified replicate in a separate cohort of 8,323 participants who reported if they had developed myopia before age 10. These 22 associations in total explain 2.9% of the variance in myopia age of onset and point toward a number of different mechanisms behind the development of myopia. One association is in the gene PRSS56, which has previously been linked to abnormally small eyes; one is in a gene that forms part of the extracellular matrix (LAMA2); two are in or near genes involved in the regeneration of 11-cis-retinal (RGR and RDH5); two are near genes known to be involved in the growth and guidance of retinal ganglion cells (ZIC2, SFRP1); and five are in or near genes involved in neuronal signaling or development. These novel findings point toward multiple genetic factors involved in the development of myopia and suggest that complex interactions between extracellular matrix remodeling, neuronal development, and visual signals from the retina may underlie the development of myopia in humans. PMID:23468642

Interactions of spatial and luminance information in the retina of chickens during myopia development.

PubMed

Feldkaemper, M; Diether, S; Kleine, G; Schaeffel, F

1999-01-01

Degrading the retinal image by frosted eye occluders produces elongated eyes and 'deprivation myopia' in a variety of animal models. The postulated retinal 'deprivation detector' is quite sensitive to even small changes in image contrast or spatial frequency composition. Because psychophysical experiments have shown that a decline in luminance shifts the contrast sensitivity function to lower spatial frequencies, it is likely that only a reduced spatial frequency range is available for image analysis to control eye growth. It is even possible that the compression might be sufficient to promote deprivation myopia. We have tested this hypothesis, using the animal model of the chicken. (1) At an ambient illumination of 550 lux (about 76 cd m-2), neutral density (ND) filters placed in front of the eye with 0.0, 0.5 or 1.0 log unit attenuation did not change refractive development. However, monocularly or binocularly attached filters with 2 log units attenuation produced 5-7 D of myopia relative to normal eyes. Black occluders were not more effective. Frosted eye occluders with little effect on image brightness (about 0.5 log units attenuation) produced much more myopia (about 16 D compared with the controls). (2) The effects of the ND filters on refractive development could not be reproduced if the ambient illumination was reduced by 2 log units. Probably, minor effects on image quality were introduced by optical imperfections of the ND filters which were more critical at low retinal image brightness. (3) In an optomotor experiment (spatial frequency 0.2 cyc deg-1, stripe speed 57 deg sec-1), it was shown that the chickens' contrast sensitivity was severely reduced when the eyes were covered by 2.0 ND filters. (4) Since there is evidence that changes in dopamine release from the retina may be one of the factors affecting the development of myopia, we have tested how selective these changes were for spatial information. It was found that dopamine release was controlled by both spatial and luminance information and that the inputs of both could be scarcely separated. (5) Because the experiments show that the eye becomes more sensitive to image degradation at low light, the human eye may also be more prone to develop myopia if the light levels are low during extended periods of near work. Copyright 1999 Academic Press.

Interactions of genes and environment in myopia.

PubMed

Feldkämper, Marita; Schaeffel, Frank

2003-01-01

Myopia is a condition in which the eye is too long for the focal length of cornea and lens, and the plane of sharp focus ends up in front of the retina. Given that the growth of the length of the eye is normally controlled with extreme precision by an image-processing feedback mechanism in the retina, myopia can either be the result of inappropriate visual stimulation, genetically determined changes in the gain or offset of the feedback loops or of inappropriate responses of the target tissues. There is no doubt that an environmental component is involved and extended near work appears to be the major risk factor. However, there is also no doubt that myopia is inherited since myopic parents are much more likely to have myopic children, and myopia is far more frequent in Asian populations than in the USA or Europe, even if groups are compared that have performed similar amounts of near work. A number of systemic or ophthalmic diseases are associated with myopia, indicating that metabolic conditions may interfere either with the gains of the feedback loops or the responses of the target tissue, the sclera. Since there is still no therapy against myopia development, research is directed toward the identification of genes that control the axial elongation of the eye.

Myopia correction in children: a meta-analysis.

PubMed

Cui, Yanhui; Li, Li; Wu, Qian; Zhao, Junyang; Chu, Huihui; Yu, Gang; Wei, Wenbin

2017-06-26

The purpose of this study was to conduct a meta-analysis comparing rigid gas permeable lenses (RGP) with soft contact lenses (SCL), spectacles and orthokeratology (OK) lenses for myopia control with respect to axial length elongation, spherical equivalent and measures of corneal curvature. Medline, Cochrane, EMBASE, and Google Scholar databases were searched to September 29, 2015 using the following keywords: rigid gas permeable contact lens; refractive error; and refractive abnormalities. Randomized controlled trials, two-arm prospective studies and retrospective studies of children with myopia treated with RGP lenses compared with spectacles, SCL, and OK lenses were included. Outcome measures were changes of axial length, spherical equivalent, flatter meridian, steeper meridian and corneal apical radius. Five studies were included. Three studies reported axial length change after 2-3 years of treatment with RGP lenses and SCL/spectacles and no difference between the groups was noted (pooled mean difference = -0.077, 95% confidence interval [CI]: -0.120 to 0.097, p = 0.840). Two studies reported a change of spherical equivalent after 2-3 years of treatment with RGP lenses and SCL/spectacles, and no difference between the groups was noted (pooled mean difference = 0.275, 95% CI: -0.390 to 0.941, p = 0.417). Two studies compared corneal curvature measures between RGP and OK lenses after 3-6 months of treatment and no differences in any measures of corneal curvature were seen. The effect of RGP lenses and SCL/spectacles on axial length elongation and spherical equivalent and of RGP and OK lenses on corneal curvature in children with myopia was similar.

Alterations in Protein Expression in Tree Shrew Sclera during Development of Lens-Induced Myopia and Recovery

PubMed Central

Norton, Thomas T.

2012-01-01

Purpose. During the development of, and recovery from, negative lens-induced myopia there is regulated remodeling of the scleral extracellular matrix (ECM) that controls the extensibility of the sclera. Difference gel electrophoresis (DIGE) was used to identify and categorize proteins whose levels are altered in this process. Methods. Two groups of five tree shrews started monocular lens wear 24 days after eye opening (days of visual experience [VE]). The lens-induced myopia (LIM) group wore a −5 D lens for 4 days. The recovery (REC) group wore a −5 D lens for 11 days and then recovered for 4 days. Two normal groups (28 and 39 days of VE; n = 5 each) were also examined, age-matched to each of the treatment groups. Refractive and A-scan measures confirmed the effect of the treatments. Scleral proteins were isolated and resolved by DIGE. Proteins that differed in abundance were identified by mass spectrometry. Ingenuity pathway analysis was used to investigate potential biological pathway interactions. Results. During normal development (28–39 days of VE), eight proteins decreased and one protein increased in relative abundance. LIM-treated eyes were myopic and longer than control eyes; LIM-control eyes were slightly myopic compared with 28N eyes, indicating a yoking effect. In both the LIM-treated and the LIM-control eyes, there was a general downregulation from normal of proteins involved in transcription, cell adhesion, and protein synthesis. Additional proteins involved in cell adhesion, actin cytoskeleton, transcriptional regulation, and ECM structural proteins differed in the LIM-treated eyes versus normal but did not differ in the control eyes versus normal. REC-treated eyes were recovering from the induced myopia. REC-control eye refractions were not significantly different from the 39N eyes, and few proteins differed from age-matched normal eyes. The balance of protein expression in the REC-treated eyes, compared with normal eyes and REC-control eyes, shifted toward upregulation or a return to normal levels of proteins involved in cell adhesion, cell division, cytoskeleton, and ECM structural proteins, including upregulation of several cytoskeleton-related proteins not affected during myopia development. Conclusions. The DIGE procedure revealed new proteins whose abundance is altered during myopia development and recovery. Many of these are involved in cell-matrix adhesions, cytoskeleton, and transcriptional regulation and extend our understanding of the remodeling that controls the extensibility of the sclera. Reductions in these proteins during minus lens wear may produce the increased scleral viscoelasticity that results in faster axial elongation. Recovery is not a mirror image of lens-induced myopia—many protein levels, decreased during LIM, returned to normal, or slightly above normal, and additional cytoskeleton proteins were upregulated. However, no single protein or pathway appeared to be responsible for the scleral changes during myopia development or recovery. PMID:22039233

Myopia progression control lens reverses induced myopia in chicks.

PubMed

Irving, Elizabeth L; Yakobchuk-Stanger, Cristina

2017-09-01

To determine whether lens induced myopia in chicks can be reversed or reduced by wearing myopia progression control lenses of the same nominal (central) power but different peripheral designs. Newly hatched chicks wore -10D Conventional lenses unilaterally for 7 days. The myopic chicks were then randomly divided into three groups: one fitted with Type 1 myopia progression control lenses, the second with Type 2 myopia progression control lenses and the third continued to wear Conventional lenses for seven more days. All lenses had -10D central power, but Type 1 and Type 2 lenses had differing peripheral designs; +2.75D and +1.32D power rise at pupil edge, respectively. Axial length and refractive error were measured on Days 0, 7 and 14. Analyses were performed on the mean differences between treated and untreated eyes. Refractive error and axial length differences between treated and untreated eyes were insignificant on Day 0. On Day 7 treated eyes were longer (T1; 0.44 ± 0.07 mm, T2; 0.27 ± 0.06 mm, C; 0.40 ± 0.06 mm) and more myopic (T1; -9.61 ± 0.52D, T2; -9.57 ± 0.61D, C; -9.50 ± 0.58D) than untreated eyes with no significant differences between treatment groups. On Day 14 myopia was reversed (+2.91 ± 1.08D), reduced (-3.83 ± 0.94D) or insignificantly increased (-11.89 ± 0.79D) in treated eyes of Type 1, Type 2 and Conventional treated chicks respectively. Relative changes in axial lengths (T1; -0.13 ± 0.09 mm, T2; 0.36 ± 0.09 mm, C; 0.56 ± 0.05 mm) were consistent with changes in refraction. Refractive error differences were significant for all group comparisons (p < 0.001). Type 1 length differences were significantly different from Conventional and Type 2 groups (p < 0.001). Myopia progression control lens designs can reverse lens-induced myopia in chicks. The effect is primarily due to axial length changes. Different lens designs produce different effects indicating that lens design is important in modifying refractive error. © 2017 The Authors. Ophthalmic and Physiological Optics published by John Wiley & Sons Ltd on behalf of College of Optometrists.

Genome-Wide Meta-Analysis of Myopia and Hyperopia Provides Evidence for Replication of 11 Loci

PubMed Central

Simpson, Claire L.; Wojciechowski, Robert; Oexle, Konrad; Murgia, Federico; Portas, Laura; Li, Xiaohui; Verhoeven, Virginie J. M.; Vitart, Veronique; Schache, Maria; Hosseini, S. Mohsen; Hysi, Pirro G.; Raffel, Leslie J.; Cotch, Mary Frances; Chew, Emily; Klein, Barbara E. K.; Klein, Ronald; Wong, Tien Yin; van Duijn, Cornelia M.; Mitchell, Paul; Saw, Seang Mei; Fossarello, Maurizio; Wang, Jie Jin; Polašek, Ozren; Campbell, Harry; Rudan, Igor; Oostra, Ben A.; Uitterlinden, André G.; Hofman, Albert; Rivadeneira, Fernando; Amin, Najaf; Karssen, Lennart C.; Vingerling, Johannes R.; Döring, Angela; Bettecken, Thomas; Bencic, Goran; Gieger, Christian; Wichmann, H.-Erich; Wilson, James F.; Venturini, Cristina; Fleck, Brian; Cumberland, Phillippa M.; Rahi, Jugnoo S.; Hammond, Chris J.; Hayward, Caroline; Wright, Alan F.; Paterson, Andrew D.; Baird, Paul N.; Klaver, Caroline C. W.; Rotter, Jerome I.; Pirastu, Mario; Meitinger, Thomas; Bailey-Wilson, Joan E.; Stambolian, Dwight

2014-01-01

Refractive error (RE) is a complex, multifactorial disorder characterized by a mismatch between the optical power of the eye and its axial length that causes object images to be focused off the retina. The two major subtypes of RE are myopia (nearsightedness) and hyperopia (farsightedness), which represent opposite ends of the distribution of the quantitative measure of spherical refraction. We performed a fixed effects meta-analysis of genome-wide association results of myopia and hyperopia from 9 studies of European-derived populations: AREDS, KORA, FES, OGP-Talana, MESA, RSI, RSII, RSIII and ERF. One genome-wide significant region was observed for myopia, corresponding to a previously identified myopia locus on 8q12 (p = 1.25×10−8), which has been reported by Kiefer et al. as significantly associated with myopia age at onset and Verhoeven et al. as significantly associated to mean spherical-equivalent (MSE) refractive error. We observed two genome-wide significant associations with hyperopia. These regions overlapped with loci on 15q14 (minimum p value = 9.11×10−11) and 8q12 (minimum p value 1.82×10−11) previously reported for MSE and myopia age at onset. We also used an intermarker linkage- disequilibrium-based method for calculating the effective number of tests in targeted regional replication analyses. We analyzed myopia (which represents the closest phenotype in our data to the one used by Kiefer et al.) and showed replication of 10 additional loci associated with myopia previously reported by Kiefer et al. This is the first replication of these loci using myopia as the trait under analysis. “Replication-level” association was also seen between hyperopia and 12 of Kiefer et al.'s published loci. For the loci that show evidence of association to both myopia and hyperopia, the estimated effect of the risk alleles were in opposite directions for the two traits. This suggests that these loci are important contributors to variation of refractive error across the distribution. PMID:25233373

Genome-wide meta-analysis of myopia and hyperopia provides evidence for replication of 11 loci.

PubMed

Simpson, Claire L; Wojciechowski, Robert; Oexle, Konrad; Murgia, Federico; Portas, Laura; Li, Xiaohui; Verhoeven, Virginie J M; Vitart, Veronique; Schache, Maria; Hosseini, S Mohsen; Hysi, Pirro G; Raffel, Leslie J; Cotch, Mary Frances; Chew, Emily; Klein, Barbara E K; Klein, Ronald; Wong, Tien Yin; van Duijn, Cornelia M; Mitchell, Paul; Saw, Seang Mei; Fossarello, Maurizio; Wang, Jie Jin; Polašek, Ozren; Campbell, Harry; Rudan, Igor; Oostra, Ben A; Uitterlinden, André G; Hofman, Albert; Rivadeneira, Fernando; Amin, Najaf; Karssen, Lennart C; Vingerling, Johannes R; Döring, Angela; Bettecken, Thomas; Bencic, Goran; Gieger, Christian; Wichmann, H-Erich; Wilson, James F; Venturini, Cristina; Fleck, Brian; Cumberland, Phillippa M; Rahi, Jugnoo S; Hammond, Chris J; Hayward, Caroline; Wright, Alan F; Paterson, Andrew D; Baird, Paul N; Klaver, Caroline C W; Rotter, Jerome I; Pirastu, Mario; Meitinger, Thomas; Bailey-Wilson, Joan E; Stambolian, Dwight

2014-01-01

Refractive error (RE) is a complex, multifactorial disorder characterized by a mismatch between the optical power of the eye and its axial length that causes object images to be focused off the retina. The two major subtypes of RE are myopia (nearsightedness) and hyperopia (farsightedness), which represent opposite ends of the distribution of the quantitative measure of spherical refraction. We performed a fixed effects meta-analysis of genome-wide association results of myopia and hyperopia from 9 studies of European-derived populations: AREDS, KORA, FES, OGP-Talana, MESA, RSI, RSII, RSIII and ERF. One genome-wide significant region was observed for myopia, corresponding to a previously identified myopia locus on 8q12 (p = 1.25×10(-8)), which has been reported by Kiefer et al. as significantly associated with myopia age at onset and Verhoeven et al. as significantly associated to mean spherical-equivalent (MSE) refractive error. We observed two genome-wide significant associations with hyperopia. These regions overlapped with loci on 15q14 (minimum p value = 9.11×10(-11)) and 8q12 (minimum p value 1.82×10(-11)) previously reported for MSE and myopia age at onset. We also used an intermarker linkage- disequilibrium-based method for calculating the effective number of tests in targeted regional replication analyses. We analyzed myopia (which represents the closest phenotype in our data to the one used by Kiefer et al.) and showed replication of 10 additional loci associated with myopia previously reported by Kiefer et al. This is the first replication of these loci using myopia as the trait under analysis. "Replication-level" association was also seen between hyperopia and 12 of Kiefer et al.'s published loci. For the loci that show evidence of association to both myopia and hyperopia, the estimated effect of the risk alleles were in opposite directions for the two traits. This suggests that these loci are important contributors to variation of refractive error across the distribution.

Melatonin and deprivation myopia in chickens.

PubMed

Hoffmann, M; Schaeffel, F

1996-01-01

Chicken eyes elongate and become myopic if they are covered with translucent diffusors which degrade the retinal image ('deprivation myopia'). Since it has been shown that dopamine D2/D4 receptors (which mediate inhibition of melatonin synthesis) are also implicated in deprivation myopia, we have studied the role of melatonin in the visual control of eye growth. We have found that (1) diurnal melatonin rhythms and melatonin content in the retina are unchanged during deprivation myopia development despite the breakdown of both diurnal growth rhythms of the eye and diurnal rhythms in retinal dopamine metabolism, (2) diurnal melatonin rhythms and melatonin content in the retina remain unchanged after application of the neurotoxin 5,7-dihydroxytryptamine (5,7-DHT) and presumably also after 6-hydroxydopamine (6-OHDA) application which both have a suppressive effect on deprivation myopia and (3) deprivation myopia was slightly reduced in both eyes after unilateral intravitreal injection of melatonin, despite that deprivation myopia is based on a mechanism intrinsic to the eye. We conclude that melatonin is not involved in the retinal signaling pathway translating visual experience to deprivation myopia.

α-adrenergic agonist brimonidine control of experimentally induced myopia in guinea pigs: A pilot study.

PubMed

Liu, Yan; Wang, Yuexin; Lv, Huibin; Jiang, Xiaodan; Zhang, Mingzhou; Li, Xuemin

2017-01-01

To investigate the efficacy of α-adrenergic agonist brimonidine either alone or combined with pirenzepine for inhibiting progressing myopia in guinea pig lens-myopia-induced models. Thirty-six guinea pigs were randomly divided into six groups: Group A received 2% pirenzepine, Group B received 0.2% brimonidine, Group C received 0.1% brimonidine, Group D received 2% pirenzepine + 0.2% brimonidine, Group E received 2% pirenzepine + 0.1% brimonidine, and Group F received the medium. Myopia was induced in the right eyes of all guinea pigs using polymethyl methacrylate (PMMA) lenses for 3 weeks. Eye drops were administered accordingly. Intraocular pressure was measured every day. Refractive error and axial length measurements were performed once a week. The enucleated eyeballs were removed for hematoxylin and eosin (H&E) and Van Gieson (VG) staining at the end of the study. The lens-induced myopia model was established after 3 weeks. Treatment with 0.1% brimonidine alone and 0.2% brimonidine alone was capable of inhibiting progressing myopia, as shown by the better refractive error (p=0.024; p=0.006) and shorter axial length (p=0.005; p=0.0017). Treatment with 0.1% brimonidine and 0.2% brimonidine combined with 2% pirenzepine was also effective in suppressing progressing refractive error (p=0.016; p=0.0006) and axial length (p=0.017; p=0.0004). The thickness of the sclera was kept stable in all groups except group F; the sclera was much thinner in the lens-induced myopia eyes compared to the control eyes. Treatment with 0.1% brimonidine alone and 0.2% brimonidine alone, as well as combined with 2% pirenzepine, was effective in inhibiting progressing myopia. The result indicates that intraocular pressure elevation is possibly a promising mechanism and potential treatment for progressing myopia.

Ptosis, extraocular motility disorder, and myopia as features of pompe disease.

PubMed

Slingerland, Niki W R; Polling, Jan Roelof; van Gelder, Catharina M; van der Ploeg, Ans T; Bleyen, Isabel

2011-03-01

The assets of this report are a thorough description of new clinical findings, namely the combination of ptosis, extraocular motility disorder and myopia, in consequence of prolonged survival in classic infantile-onset Pompe disease through enzyme therapy. Single case description. This manuscript describes a combination of ptosis, extraocular motility disorder and myopia in a 4.5-year-old patient with classic infantile-onset Pompe disease, who survived through enzyme therapy. This patient was treated with a bilateral frontalis suspension (modified Crawford technique) using prolene 3-0 sutures. The combination of ptosis, extraocular motility disorder and myopia, is a new clinical finding in children with classic infantile-onset Pompe disease.

A comparison between Goldmann applanation tonometry and dynamic contour tonometry after photorefractive keratectomy.

PubMed

Sadigh, Afshin Lotfi; Fouladi, Rohollah F; Hashemi, Hassan; Beheshtnejad, Amir Houshang

2013-02-01

The intraocular pressure (IOP) could be measured by both Goldmann applanation tonometry (GAT) and dynamic contour tonometry (DCT). Although these two methods have been discussed widely after laser-assisted sub-epithelial keratectomy (LASIK), there is little data in the cases undergoing photorefractive keratectomy (PRK). We aimed to compare the changes of IOP measurements obtained by GAT and DCT after PRK for myopia/myopic astigmatism. This prospective study enrolled 77 candidates (154 eyes) for PRK to correct myopia or myopic astigmatism and 30 matched patients (30 eyes) with myopia or myopic astigmatism who served as controls. Changes of the IOP measurements (ΔIOP) obtained by GAT and DCT before and at 6 months after PRK in the operated eyes, and at baseline and 6 months later in the controls, were documented. Changes of the central corneal thickness (ΔCCT) were determined in the same fashion. The mean IOP readings obtained by DCT were comparable before and at 6 months after procedure (18.34 ± 3.03 mmHg and 17.87 ± 2.61 mmHg respectively, p = 0.41); whereas the mean IOP reading obtained by GAT decreased significantly 6 months postoperatively (17.92 ± 3.63 mmHg and 16.25 ± 2.66 mmHg, p < 0.001). A significant correlation was present between the ΔIOP obtained by GAT and ΔCCT (r = 0.61, p < 0.001). Similar correlation was not significant between the DCT-obtained ΔIOP and the ΔCCT (r = 0.07, p = 0.44). The mean ΔIOP obtained by GAT was significantly higher in the operated eyes than in the controls (-1.54 ± 1.45 vs 0.07 ± 0.44 mmHg, p = 0.02). The mean DCT-obtained ΔIOP was just marginally insignificant between the operated and nonoperated eyes (-0.63 ± 0.59 vs 0.02 ± 0.38 mmHg respectively; p = 0.09). The authors recommend DCT after PRK in the cases with myopia or myopic astigmatism.

Wnt Signaling in Form Deprivation Myopia of the Mice Retina

PubMed Central

Ma, Mingming; Zhang, Zhengwei; Du, Ergang; Zheng, Wenjing; Gu, Qing; Xu, Xun; Ke, Bilian

2014-01-01

Background The canonical Wnt signaling pathway plays important roles in cellular proliferation and differentiation, axonal outgrowth, cellular maintenance in retinas. Here we test the hypothesis that elements of the Wnt signaling pathway are involved in the regulation of eye growth and prevention of myopia, in the mouse form-deprivation myopia model. Methodology/Principal Findings (1) One hundred twenty-five C57BL/6 mice were randomly distributed into form-deprivation myopia and control groups. Form-deprivation myopia (FDM) was induced by suturing the right eyelid, while the control group received no treatment. After 1, 2, and 4 weeks of treatment, eyes were assessed in vivo by cycloplegic retinoscopic refraction and axial length measurement by photography or A-scan ultrasonography. Levels of retinal Wnt2b, Fzd5 and β-catenin mRNA and protein were evaluated using RT-PCR and western blotting, respectively. (2) Another 96 mice were divided into three groups: control, drugs-only, and drugs+FDM (by diffuser). Experimentally treated eyes in the last two groups received intravitreal injections of vehicle or the proteins, DKK-1 (Wnt-pathway antagonist) or Norrin (Wnt-pathway agonist), once every three days, for 4 injections total. Axial length and retinoscopic refraction were measured on the 14th day of form deprivation. Following form-deprivation for 1, 2, and 4 weeks, FDM eyes had a relatively myopic refractive error, compared with contralateral eyes. There were no significant differences in refractive error between right and left eye in control group. The amounts of Wnt2b, Fzd5 and β-catenin mRNA and protein were significantly greater in form-deprived myopia eyes than in control eyes.DKK-1 (antagonist) reduced the myopic shift in refractive error and increase in axial elongation, whereas Norrin had the opposite effect in FDM eyes. Conclusions/Significance Our studies provide the first evidence that the Wnt2b signaling pathway may play a role in the development and progression of form-deprivation myopia, in a mammalian model. PMID:24755605

Wnt signaling in form deprivation myopia of the mice retina.

PubMed

Ma, Mingming; Zhang, Zhengwei; Du, Ergang; Zheng, Wenjing; Gu, Qing; Xu, Xun; Ke, Bilian

2014-01-01

The canonical Wnt signaling pathway plays important roles in cellular proliferation and differentiation, axonal outgrowth, cellular maintenance in retinas. Here we test the hypothesis that elements of the Wnt signaling pathway are involved in the regulation of eye growth and prevention of myopia, in the mouse form-deprivation myopia model. (1) One hundred twenty-five C57BL/6 mice were randomly distributed into form-deprivation myopia and control groups. Form-deprivation myopia (FDM) was induced by suturing the right eyelid, while the control group received no treatment. After 1, 2, and 4 weeks of treatment, eyes were assessed in vivo by cycloplegic retinoscopic refraction and axial length measurement by photography or A-scan ultrasonography. Levels of retinal Wnt2b, Fzd5 and β-catenin mRNA and protein were evaluated using RT-PCR and western blotting, respectively. (2) Another 96 mice were divided into three groups: control, drugs-only, and drugs+FDM (by diffuser). Experimentally treated eyes in the last two groups received intravitreal injections of vehicle or the proteins, DKK-1 (Wnt-pathway antagonist) or Norrin (Wnt-pathway agonist), once every three days, for 4 injections total. Axial length and retinoscopic refraction were measured on the 14th day of form deprivation. Following form-deprivation for 1, 2, and 4 weeks, FDM eyes had a relatively myopic refractive error, compared with contralateral eyes. There were no significant differences in refractive error between right and left eye in control group. The amounts of Wnt2b, Fzd5 and β-catenin mRNA and protein were significantly greater in form-deprived myopia eyes than in control eyes.DKK-1 (antagonist) reduced the myopic shift in refractive error and increase in axial elongation, whereas Norrin had the opposite effect in FDM eyes. Our studies provide the first evidence that the Wnt2b signaling pathway may play a role in the development and progression of form-deprivation myopia, in a mammalian model.

Myopia among school students in rural China (Yunnan).

PubMed

Qian, Deng-Juan; Zhong, Hua; Li, Jun; Niu, Zhiqiang; Yuan, Yuansheng; Pan, Chen-Wei

2016-07-01

We described the prevalence and associated factors of myopia and high myopia in school children of different ethnicities in a rural community in Yunnan province, China. A total of 7681 (93.4%) primary and secondary school students aged 5-16 years in Mangshi participated in this study. Cycloplegic refraction was performed using an auto-refractor. Information regarding demographic factors, socioeconomic status and lifestyle-related exposures were collected using a questionnaire. Multivariate logistic regression models were fitted to estimate the risk factors for myopia and high myopia. The overall prevalence of myopia and high myopia was 39.1% (95% confidence interval [CI]: 38.0, 40.2) and 0.6% (95% CI: 0.4, 0.8) in this study. Myopia prevalence increased significantly with increasing age (p for trend <0.001). Girls were more likely to have myopia compared with boys (p < 0.001). In multivariate analysis, the presence of myopia was associated with increasing height (odds ratio [OR] = 1.02; 95% CI: 1.01, 1.03), computer use (OR = 1.17; 95% CI: 1.03, 1.32), having myopic father (OR = 1.56; 95% CI: 1.24, 1.94), having myopic mother (OR = 1.33; 95% CI: 1.08, 1.63), and increasing time on reading (OR = 1.18; 95% CI: 1.09, 1.28) after adjusting for age, sex and ethnicity. Nowadays myopia but not high myopia is prevalent among school children in rural China. Significant ethnic differences in myopia prevalence were not observed. A significant 'cohort effect' of myopia previously observed in urban cities had occurred in rural communities in China. © 2016 The Authors Ophthalmic & Physiological Optics © 2016 The College of Optometrists.

Prevalence and associated factors of myopia among primary and middle school-aged students: a school-based study in Guangzhou

PubMed Central

Guo, L; Yang, J; Mai, J; Du, X; Guo, Y; Li, P; Yue, Y; Tang, D; Lu, C; Zhang, W-H

2016-01-01

Purpose To estimate the prevalence of myopia among primary and middle school-aged students in Guangzhou and to explore the potentially contributing factors to myopia. Methods This cross-sectional study was based on a sample of students in grades 1–6 and grades 7–9. Data were collected from refractive error measurements and a structured questionnaire. Results A total of 3055 participants were involved in this analysis, and the overall prevalence of myopia was 47.4% (95% confidence interval (CI)= 45.6–49.2%). The prevalence of myopia in students increased along with the growth of grade level; the prevalence of myopia in students in grade 1 was only 0.2%, as it increased to 38.8% in students in grade 3, and the rate was the highest (68.4%) in students in grade 9. Girls were at a higher risk of myopia than boys (adjusted odds ratio=1.22, 95% CI=1.04–1.44). Both male and female students whose distance of reading was longer than 25 cm were less likely to have myopia and who have one or two myopic parents were at a higher risk of myopia. In addition, reading for pleasure more than 2 h per day (adjusted odds ratio=1.84, 95% CI=1.09–3.12) was only positively associated with myopia in boys and spending time watching television per week was only positively associated with myopia in girls. Conclusion Myopia in students is a significant public health problem in Guangzhou. Female gender, higher grade, longer time spent for near work, shorter distance of near work, and parental myopia were shown to be associated with the increasing risk of myopia in children. PMID:26965016

[Peripheral refraction and retinal contour in congenital and acquired high myopia].

PubMed

Tarutta, E P; Markosyan, G A; Milash, S V

to perform a comparative study of peripheral refraction and retinal contour in patients with congenital versus acquired high myopia. A total of 30 patients (60 eyes) with high myopia aged 8 to 18 years (11.2±0.32 years on average) were examined. The patients were divided into 2 groups. Group 1 consisted of 21 patients (42 eyes) with acquired myopia of -6.0 to -10.25 diopters (-7.55±0.17 diopters on average), group 2 - of 9 patients (18 eyes) with congenital myopia of -8.75 to -28.75 diopters (-16.39±1.24 diopters on average). Using the Grand Seiko WR-5100K binocular open-field autoref/keratometer (Japan), relative peripheral refraction was assessed with account to relative peripheral eye length measured by the IOL Master partial coherent interferometer ('Carl Zeiss', Germany) at 15° and 30° nasally and temporally from the foveal center along the horizontal meridian. In acquired myopia, relative peripheral refraction and relative peripheral eye length readings evidenced the formation of peripheral hyperopic defocus in all examined zones. Congenital high myopia cases were notable for myopic defocus at 15° of the nasal retina (N15 zone): -0.67±0.33 diopters against the eye length change of -0.33±0.13 mm. The research helped identify retinal contour changes characteristic of congenital myopia and indicative of posterior pole irregularity.

Association of Axial Length With Risk of Uncorrectable Visual Impairment for Europeans With Myopia.

PubMed

Tideman, J Willem L; Snabel, Margaretha C C; Tedja, Milly S; van Rijn, Gwyneth A; Wong, King T; Kuijpers, Robert W A M; Vingerling, Johannes R; Hofman, Albert; Buitendijk, Gabriëlle H S; Keunen, Jan E E; Boon, Camiel J F; Geerards, Annette J M; Luyten, Gregorius P M; Verhoeven, Virginie J M; Klaver, Caroline C W

2016-12-01

Myopia (ie, nearsightedness) is becoming the most common eye disorder to cause blindness in younger persons in many parts of the world. Visual impairment due to myopia is associated with structural changes of the retina and the globe because of elongation of the eye axis. How axial length-a sum of the anterior chamber depth, lens thickness, and vitreous chamber depth-and myopia relate to the development of visual impairment over time is unknown. To evaluate the association between axial length, spherical equivalent, and the risk of visual impairment and to make projections of visual impairment for regions with high prevalence rates. This cross-sectional study uses population-based data from the Rotterdam Study I (1990 to 1993), II (2000 to 2002), and III (2006 to 2008) and the Erasmus Rucphen Family Study (2002 to 2005) as well as case-control data from the Myopia Study (2010 to 2012) from the Netherlands. In total, 15 404 individuals with data on spherical equivalent and 9074 individuals with data on axial length were included in the study; right eyes were used for analyses. Data were analyzed from September 2014 to May 2016. Visual impairment and blindness (defined according to the World Health Organization criteria as a visual acuity less than 0.3) and predicted rates of visual impairment specifically for persons with myopia. Of the 15 693 individuals included in this study, the mean (SD) age was 61.3 (11.4) years, and 8961 (57.1%) were female. Axial length ranged from 15.3 to 37.8 mm; 819 individuals had an axial length of 26 mm or greater. Spherical equivalent ranged from -25 to +14 diopters; 796 persons had high myopia (ie, a spherical equivalent of -6 diopters or less). The prevalence of visual impairment varied from 1.0% to 4.1% in the population-based studies, was 5.4% in the Myopia Study, and was 0.3% in controls. The prevalence of visual impairment rose with increasing axial length and spherical equivalent, with a cumulative incidence (SE) of visual impairment of 3.8% (1.3) for participants aged 75 years with an axial length of 24 to less than 26 mm and greater than 90% (8.1) with an axial length of 30 mm or greater. The cumulative risk (SE) of visual impairment was 5.7% (1.3) for participants aged 60 years and 39% (4.9) for those aged 75 years with a spherical equivalent of -6 diopters or less. Projections of these data suggest that visual impairment will increase 7- to 13-fold by 2055 in high-risk areas. This study demonstrated that visual impairment is associated with axial length and spherical equivalent and may be unavoidable at the most extreme values in this population. Developing strategies to prevent the development of myopia and its complications could help to avoid an increase of visual impairment in the working-age population.

Clinical results of the laser-assisted in situ keratomileusis (LASIK) for myopia

NASA Astrophysics Data System (ADS)

Guo, Hai-ke; Yao, Da-qing; Gui, Lu-ping

1998-11-01

To observe and analyze the refractive and complications of the LASIK for corrections of myopia. With the microlamellar keratoplasty and the excimer laser, LASIK was performed on 194 cases. According to the preoperative spherical equivalent refraction, divide the patients into three groups.

A Systematic Review and Meta-Analysis on the Safety of Vascular Endothelial Growth Factor (VEGF) Inhibitors for the Treatment of Retinopathy of Prematurity

PubMed Central

Pertl, Laura; Steinwender, Gernot; Mayer, Christoph; Hausberger, Silke; Pöschl, Eva-Maria; Wackernagel, Werner; Wedrich, Andreas; El-Shabrawi, Yosuf; Haas, Anton

2015-01-01

Introduction Laser photocoagulation is the current gold standard treatment for proliferative retinopathy of prematurity (ROP). However, it permanently reduces the visual field and might induce myopia. Vascular endothelial growth factor (VEGF) inhibitors for the treatment of ROP may enable continuing vascularization of the retina, potentially allowing the preservation of the visual field. However, for their use in infants concern remains. This meta-analysis explores the safety of VEGF inhibitors. Methods The Ovid Interface was used to perform a systematic review of the literature in the databases PubMed, EMBASE and the Cochrane Library. Results This meta-analysis included 24 original reports (including 1.457 eyes) on VEGF inhibitor treatment for ROP. The trials were solely observational except for one randomized and two case-control studies. We estimated a 6-month risk of retreatment per eye of 2.8%, and a 6-month risk of ocular complication without the need of retreatment of 1.6% per eye. Systemic complications were only reported as isolated incidents. Discussion VEGF inhibitors seem to be associated with low recurrence rates and ocular complication rates. They may have the benefit of potentially allowing the preservation of visual field and lower rates of myopia. Due to the lack of data, the risk of systemic side effects cannot be assessed. PMID:26083024

M to L cone ratios determine eye sizes and baseline refractions in chickens.

PubMed

Gisbert, Sandra; Schaeffel, Frank

2018-07-01

Following a hypothesis raised by M. and J. Neitz, Seattle, we have tested whether the abundance and the ratio of Long wavelength-sensitive (L) to Middle wavelength-sensitive (M) cones may affect eye size and development of myopia in the chicken. Fourteen chickens were treated with frosted plastic diffusers in front of one eye on day 10 post-hatching for a period of 7 days to induce deprivation myopia. Ocular dimensions were measured by A-scan ultrasonography at the beginning and at the end of the treatment and development of refractive state was tracked using infrared photorefraction. At the end of the treatment period, L and M cone densities and ratios were analyzed in retinal flat mounts of both myopic and control eyes, using the red and yellow oil droplets as markers. Because large numbers of cones were counted (>10000), software was written in Visual C++ for automated cone detection and density analysis. (1) On average, 9.7 ± 1.7D of deprivation myopia was induced in 7 days (range from 6.8D to 13.7D) with an average increase in axial length by 0.65 ± 0.20 mm (range 0.42 mm-1.00 mm), (2) the increase in vitreous chamber depth was correlated with the increase in myopic refractive error, (3) average central M cone densities were 10,498 cells/mm 2 , and L cone densities 9574 cells/mm 2 . In the periphery, M cone densities were 6343 cells/mm 2 and L cones 5735 cells/mm 2 (4) M to L cone ratios were highly correlated in both eyes of each animal (p < 0.01 in all cases), (5) the most striking finding was that ratios of M to L cones were significantly correlated with vitreous chamber depths and refractive states in the control eyes with normal vision, both in the central and peripheral retinas (p < 0.05 to p < 0.01), (6) M to L cone ratios did however not predict the amount of deprivation myopia that could be induced. M and L cone ratios are most likely genetically determined in each animal. The more L cones, the deeper the vitreous chambers and the more myopic were the refractions in eyes. M to L cone ratios may determine the set point of emmetropization and thereby ultimately the probability of becoming myopic. Deprivation myopia was not determined by M to L cone ratios. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Mouse Experimental Myopia Has Features of Primate Myopia

PubMed Central

Tkatchenko, Tatiana V.; Shen, Yimin

2010-01-01

Purpose. Several recent studies have suggested that experimental myopia can be induced in mice. However, it is not clear what role the photopic visual input plays in this process and whether mouse myopia is similar to human myopia. The purpose of this study was to carry out an in vivo high-resolution analysis of changes in ocular components and refractive state of the eye upon induction of experimental myopia in mice. Methods. A high-resolution small animal MRI system and a high-resolution automated eccentric infrared photorefractor were used to analyze changes of the refractive state and ocular components in C57BL/6J mice associated with experimental myopia induced by diffusers and −25 D lenses under photopic conditions. Results. The authors found that both diffusers and −25 D lenses induce myopia in C57BL/6J mice under photopic conditions (continuous light, 200 ± 15 lux). The extent of myopic shift induced by −25 D lenses was greater than the shift induced by diffusers (−15.2 ± 0.7 D, lenses; −12.0 ± 1.4 D, diffusers). Myopia in mice is attributed to an increase in size of the postequatorial segment of the eye. Experimental myopia in mice can be induced only during the susceptible period in postnatal development, which ends around postnatal day 67. Conclusions. Both diffusers and spectacle lenses induce myopia in mice under photopic conditions, during the susceptible period in postnatal development. Myopia in mice is associated with elongation of the vitreous chamber of the eye, as in humans and nonhuman primates. PMID:19875658

[The relationship between accommodative accuracy at different near-work distances and early-onset myopia].

PubMed

Yu, Q W; Zhang, P; Zhou, S B; Hu, Y; Ji, M X; Luo, Y C; You, H L; Yao, Z X

2016-07-01

To observe the accommodative accuracy of children with early-onset myopia at different near-work distances, and discuss the relationship between accommodative accuracy and early-onset myopia. This was a case-control study. Thirty-seven emmetropic children, 41 early-onset myopic children without correction, and 39 early-onset myopic children with spectacles, aged 7 to 13 years, were included. Measures of refractive errors and accommodative accuracy at four near-work distances, including 50 cm, 40 cm, 30 cm, and 20 cm, were made using the binocular fusion cross cylinder (FCC) of an automatic phoropter. Most candidates showed accommodative lags, including the children with emmetropia. The ratio of lags in all candidates at different near-work distances was 75.21% (50 cm), 87.18% (40 cm), 92.31% (30 cm), and 98.29% (20 cm), respectively. All accommodative accuracies became worse, and the accommodative lag ratio and values of FCC increased, along with the shortening of the distance. The difference in accommodative accuracy among groups was statistically significant at 30 cm (χ(2)=7.852, P= 0.020) and 20 cm (χ(2)=6.480, P=0.039). The values of FCC among groups were significantly different at 30 cm (F=3.626, P=0.030) and 20 cm (F=3.703, P=0.028), but not at 50 cm and 40 cm (P>0.05). In addition, the FCC values of 30 cm and 20 cm had a statistically significant difference between myopic children without correction [(1.25±0.44) D and (1.76±0.43) D] and emmetropic children [(0.95±0.52) D and (1.41±0.58) D] (P=0.012, 0.008). The correlation between diopters of myopia and accommodative accuracy at different nearwork distances was not statistically significant (P>0.05). However, the correlation between diopters of myopia and the accommodative lag value (FCC) at 20 cm was statistically significant (r=0.246, P=0.028). The closer the near-work distance is, the worse the accommodative accuracy is. This is more significant in early-onset myopia, especially myopia without correction, than emmetropia. Wearing spectacles may improve the threshold and sensitivity of accommodations, and the accommodative accuracy at near-work distances (<30 cm) to some extent. The poor accommodative accuracy at near-work distances may be not related to early-onset myopia, but the value of FCC (20 cm) is related to early-onset myopia. The higher the FCC value is, the higher the diopter is. (Chin J Ophthalmol, 2016, 52: 520-524).

[Prevalence of myopia and influencing factors among primary and middle school students in 6 provinces of China].

PubMed

Zhou, Jia; Ma, Yinghua; Ma, Jun; Zou, Zhiyong; Meng, Xiangkun; Tao, Fangbiao; Luo, Chunyan; Jing, Jin; Pan, Dehong; Luo, Jiayou; Zhang, Xin; Wang, Hong; Zhao, Haiping

2016-01-01

To understand the prevalence of myopia in primary and middle school students in 6 provinces and the possible influencing factors. Primary and middle school students were selected through multistage cluster sampling in 60 primary and middle schools in 6 provinces in China. The questionnaire survey and eyesight test were conducted among all the students selected according to the national student's physique and health survey protocol. Pearson chi-square test and binary multivariate logistic regression analysis were done to identify the influencing factors for myopia in students. The prevalence of myopia among primary and middle school students surveyed was 55.7%, the gender specific difference was statistically significant (59.7% for girls, 51.9% for boys) (P<0.01). The prevalence of myopia increased with age obviously. The prevalence was 35.8% in age group 6-8 years, 58.9% in age group 10-12 years, 73.4% in age group 13-15 years and 81.2% in age group 16-18 years, the differences were statistically significant (P<0.001). Single factor and multivariate analysis showed that parents' myopia, distance between computer screen and eyes, distance less than 30 cm between eyes and book while reading, distance less than 10 cm between chest and the table edge while studying, distance less than 3 cm between fingers and pen tip, sleep time, average outdoor activity time during last week, school sport activities in the afternoon, the size of television set at home, time spent on watching TV and playing computer were the influencing factors for myopia. The prevalence of myopia is till high in primary and middle school students. Myopia is associated with both genetic factors and individual eye health related behaviors.

Evaluation of the effectiveness of laser in situ keratomileusis and photorefractive keratectomy for myopia: a meta-analysis.

PubMed

Yang, Xin-Jun; Yan, Hong-Tao; Nakahori, Yutaka

2003-08-01

To evaluate the effectiveness of laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) for correcting myopia. Study selection, data extraction, and quality assessment were performed by two of authors independently. Summary odds ratios and 95% confidence intervals were calculated by DerSimonian & Laird random-effects model and Mantel-Haenszel (fixed-effects) model. All calculations were based on an intention-to-treat and per protocol analysis. Five hundred and eighty eyes (476 patients) from 5 randomized controlled trials were included in this study. At > or = 6 months follow-up, by random-effects model, the pooled odds ratios (OR, for LASIK vs. PRK) of postoperative uncorrected visual acuity (UCVA) of 20/20 or better for all trials were 1.31 (95% CI=0.77-2.22) by per protocol analysis and 1.18 (95% CI=0.74-1.88) by intention-to-treat analysis. In the refractive outcome, the pooled OR of the postoperative spherical equivalent refraction within +/-0.5 diopter (D) of emmetropia did not show any statistical significance, for which the OR were 0.75 (95% CI=0.48-1.18) by per protocol analysis and 0.70 (95% CI=0.47-1.04) by intention-to-treat analysis. LASIK and PRK were found to be similarly effective for the correction of myopia from -1.5 to -15.0 D in a greater than 6 month follow-up.

Linkage Analysis of Quantitative Refraction and Refractive Errors in the Beaver Dam Eye Study

PubMed Central

Duggal, Priya; Lee, Kristine E.; Cheng, Ching-Yu; Klein, Ronald; Bailey-Wilson, Joan E.; Klein, Barbara E. K.

2011-01-01

Purpose. Refraction, as measured by spherical equivalent, is the need for an external lens to focus images on the retina. While genetic factors play an important role in the development of refractive errors, few susceptibility genes have been identified. However, several regions of linkage have been reported for myopia (2q, 4q, 7q, 12q, 17q, 18p, 22q, and Xq) and for quantitative refraction (1p, 3q, 4q, 7p, 8p, and 11p). To replicate previously identified linkage peaks and to identify novel loci that influence quantitative refraction and refractive errors, linkage analysis of spherical equivalent, myopia, and hyperopia in the Beaver Dam Eye Study was performed. Methods. Nonparametric, sibling-pair, genome-wide linkage analyses of refraction (spherical equivalent adjusted for age, education, and nuclear sclerosis), myopia and hyperopia in 834 sibling pairs within 486 extended pedigrees were performed. Results. Suggestive evidence of linkage was found for hyperopia on chromosome 3, region q26 (empiric P = 5.34 × 10−4), a region that had shown significant genome-wide evidence of linkage to refraction and some evidence of linkage to hyperopia. In addition, the analysis replicated previously reported genome-wide significant linkages to 22q11 of adjusted refraction and myopia (empiric P = 4.43 × 10−3 and 1.48 × 10−3, respectively) and to 7p15 of refraction (empiric P = 9.43 × 10−4). Evidence was also found of linkage to refraction on 7q36 (empiric P = 2.32 × 10−3), a region previously linked to high myopia. Conclusions. The findings provide further evidence that genes controlling refractive errors are located on 3q26, 7p15, 7p36, and 22q11. PMID:21571680

Clinical results of excimer laser photorefractive keratectomy: a multicenter study of 265 eyes.

PubMed

Aron-Rosa, D S; Colin, J; Aron, B; Burin, N; Cochener, B; Febraro, J L; Gallinaro, C; Ganem, S; Valdes, R

1995-11-01

Efficacy, predictability, and safety of excimer laser photorefractive keratectomy were evaluated at centers in Paris and Brest, France. Photoablation was performed with the VISX laser on 265 eyes (151 at the Paris center and 114 at the Brest center). The eyes were clinically and statistically evaluated over a six month follow-up. Initial myopia ranged from -0.7 to -19.4 diopters (D) (mean spherical equivalent [SE] -5.9 D) in the Paris center and from -0.9 to -14.5 D (SE -4.5 D) in the Brest center. At both centers, the mean uncorrected visual acuity was worse than 20/200; over 90% of cases in each center had a best uncorrected visual acuity of 20/100 or worse. Results are reported globally and for subgroups of myopia: Group A, SE better than or equal to -3.0 D; Group B, SE worse than -3.0 D and better than or equal to -7.0 D; Group C, SE worse than -7.0 D. Uncorrected visual acuity was significantly improved in the patients followed for six months; 64% of Paris cases and 62% of Brest cases obtained an uncorrected visual acuity of 20/40 or better. Predictability of the treatment was good; 67% of Paris eyes and 74% of Brest eyes were less than 1.0 D from the intended correction after six months. The data suggest that the initial myopia affected the efficacy and predictability of the treatment; results in the mild to moderate myopia eyes were significantly better than results in the severe myopia eyes. One case of visual acuity regression (less than one line) was observed in the two groups. This was associated with corneal haze of moderate intensity.

Myopia induced by flickering light in guinea pig eyes is associated with increased rather than decreased dopamine release.

PubMed

Luo, Xiumei; Li, Bing; Li, Tao; Di, Yue; Zheng, Changyue; Ji, Shunmei; Ma, Yuanyuan; Zhu, Jie; Chen, Xuefeng; Zhou, Xiaodong

2017-01-01

It is well known that the dopaminergic signaling pathway plays a pivotal role in the control of axial elongation. Much research has shown that retinal dopamine (DA) is decreased in experimental myopia, but the exact alteration in DA quantity underlying the myopia model induced by flickering light (FL) has not yet been fully elucidated. Therefore, in this study, we first attempted to prove the feasibility of the myopia model induced by FL and then to determine whether and how DA and its receptors changed in myopia induced by FL. Forty-five 2-week-old guinea pigs were randomly divided into three groups, as follows: the control group, form-deprivation myopia (FDM) group, and FL-induced myopia (FLM) group. Animals in the control and FDM groups were raised under normal illumination, and the right eyes of the FDM group were covered with semitransparent hemispherical plastic shells serving as eye diffusers. Guinea pigs in the FLM group were raised under illumination with a duty cycle of 50% at a flash rate of 0.5 Hz. The refraction, axial length (AL), and corneal radius of curvature (CRC) were measured using streak retinoscopy, A-scan ultrasonography, and keratometry, respectively, before and after 2, 4, 6, and 8 weeks of treatment. The contents of DA, 3,4-dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (HVA) in the retina, vitreous body, and RPE were measured at the end of the 8-week experiment using high-performance liquid chromatography (HPLC). The numbers of retinal D1 DA receptor (D1DR) and D2 DA receptor (D2DR) were evaluated via immunohistofluorescence and western blot assay. The refraction of the FLM group became more myopic throughout the experimental period, which was mainly indicated by decreased refraction and a longer AL compared with the control group (p<0.05). The contents of DA, DOPAC, and HVA in the retina, vitreous body, and RPE of the FLM group were significantly increased, but decreased in the FDM group, compared with those of the control group (both p<0.05). Like form-deprived eyes, the expressions of retinal D1DR and D2DR in FL eyes were significantly upregulated compared with controls (p<0.05). Myopia can be induced by 0.5-Hz FL in guinea pigs at puberty. Contrary to FDM, dopaminergic neuron activity and DA release were significantly elevated in FLM. Like in FDM, the expressions of D1DR and D2DR were upregulated in FLM. Thus, the results of our study may further demonstrate that the DA system is associated with the development of myopia.

Myopia induced by flickering light in guinea pig eyes is associated with increased rather than decreased dopamine release

PubMed Central

Luo, Xiumei; Li, Bing; Li, Tao; Di, Yue; Zheng, Changyue; Ji, Shunmei; Ma, Yuanyuan; Zhu, Jie; Chen, Xuefeng

2017-01-01

Purpose It is well known that the dopaminergic signaling pathway plays a pivotal role in the control of axial elongation. Much research has shown that retinal dopamine (DA) is decreased in experimental myopia, but the exact alteration in DA quantity underlying the myopia model induced by flickering light (FL) has not yet been fully elucidated. Therefore, in this study, we first attempted to prove the feasibility of the myopia model induced by FL and then to determine whether and how DA and its receptors changed in myopia induced by FL. Methods Forty-five 2-week-old guinea pigs were randomly divided into three groups, as follows: the control group, form-deprivation myopia (FDM) group, and FL-induced myopia (FLM) group. Animals in the control and FDM groups were raised under normal illumination, and the right eyes of the FDM group were covered with semitransparent hemispherical plastic shells serving as eye diffusers. Guinea pigs in the FLM group were raised under illumination with a duty cycle of 50% at a flash rate of 0.5 Hz. The refraction, axial length (AL), and corneal radius of curvature (CRC) were measured using streak retinoscopy, A-scan ultrasonography, and keratometry, respectively, before and after 2, 4, 6, and 8 weeks of treatment. The contents of DA, 3,4-dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (HVA) in the retina, vitreous body, and RPE were measured at the end of the 8-week experiment using high-performance liquid chromatography (HPLC). The numbers of retinal D1 DA receptor (D1DR) and D2 DA receptor (D2DR) were evaluated via immunohistofluorescence and western blot assay. Results The refraction of the FLM group became more myopic throughout the experimental period, which was mainly indicated by decreased refraction and a longer AL compared with the control group (p<0.05). The contents of DA, DOPAC, and HVA in the retina, vitreous body, and RPE of the FLM group were significantly increased, but decreased in the FDM group, compared with those of the control group (both p<0.05). Like form-deprived eyes, the expressions of retinal D1DR and D2DR in FL eyes were significantly upregulated compared with controls (p<0.05). Conclusions Myopia can be induced by 0.5-Hz FL in guinea pigs at puberty. Contrary to FDM, dopaminergic neuron activity and DA release were significantly elevated in FLM. Like in FDM, the expressions of D1DR and D2DR were upregulated in FLM. Thus, the results of our study may further demonstrate that the DA system is associated with the development of myopia. PMID:28966549

Does Vitamin D Mediate the Protective Effects of Time Outdoors On Myopia? Findings From a Prospective Birth Cohort

PubMed Central

Guggenheim, Jeremy A.; Williams, Cathy; Northstone, Kate; Howe, Laura D.; Tilling, Kate; St Pourcain, Beate; McMahon, George; Lawlor, Debbie A.

2014-01-01

Purpose. More time outdoors is associated with a lesser risk of myopia, but the underlying mechanism is unclear. We tested the hypothesis that 25-hydroxyvitamin D (vitamin D) mediates the protective effects of time outdoors against myopia. Methods. We analyzed data for children participating in the Avon Longitudinal Study of Parents and Children (ALSPAC) population-based birth cohort: noncycloplegic autorefraction at age 7 to 15 years; maternal report of time outdoors at age 8 years and serum vitamin D2 and D3 at age 10 years. A survival analysis hazard ratio (HR) for incident myopia was calculated for children spending a high- versus low-time outdoors, before and after controlling for vitamin D level (N = 3677). Results. Total vitamin D and D3, but not D2, levels were higher in children who spent more time outdoors (mean [95% confidence interval (CI)] vitamin D in nmol/L: Total, 60.0 [59.4–60.6] vs. 56.9 [55.0–58.8], P = 0.001; D3, 55.4 [54.9–56.0] vs. 53.0 [51.3–54.9], P = 0.014; D2, 5.7 [5.5–5.8] vs. 5.4 [5.1–5.8], P = 0.23). In models including both time outdoors and sunlight-exposure–related vitamin D, there was no independent association between vitamin D and incident myopia (Total, HR = 0.83 [0.66–1.04], P = 0.11; D3, HR = 0.89 [0.72–1.10], P = 0.30), while time outdoors retained the same strong negative association with incident myopia as in unadjusted models (HR = 0.69 [0.55–0.86], P = 0.001). Conclusions. Total vitamin D and D3 were biomarkers for time spent outdoors, however there was no evidence they were independently associated with future myopia. PMID:25406278

Increasing Prevalence of Myopia in Europe and the Impact of Education

PubMed Central

Williams, Katie M.; Bertelsen, Geir; Cumberland, Phillippa; Wolfram, Christian; Verhoeven, Virginie J.M.; Anastasopoulos, Eleftherios; Buitendijk, Gabriëlle H.S.; Cougnard-Grégoire, Audrey; Creuzot-Garcher, Catherine; Erke, Maja Gran; Hogg, Ruth; Höhn, René; Hysi, Pirro; Khawaja, Anthony P.; Korobelnik, Jean-François; Ried, Janina; Vingerling, Johannes R.; Bron, Alain; Dartigues, Jean-François; Fletcher, Astrid; Hofman, Albert; Kuijpers, Robert W.A.M.; Luben, Robert N.; Oxele, Konrad; Topouzis, Fotis; von Hanno, Therese; Mirshahi, Alireza; Foster, Paul J.; van Duijn, Cornelia M.; Pfeiffer, Norbert; Delcourt, Cécile; Klaver, Caroline C.W.; Rahi, Jugnoo; Hammond, Christopher J.

2015-01-01

Purpose To investigate whether myopia is becoming more common across Europe and explore whether increasing education levels, an important environmental risk factor for myopia, might explain any temporal trend. Design Meta-analysis of population-based, cross-sectional studies from the European Eye Epidemiology (E3) Consortium. Participants The E3 Consortium is a collaborative network of epidemiological studies of common eye diseases in adults across Europe. Refractive data were available for 61 946 participants from 15 population-based studies performed between 1990 and 2013; participants had a range of median ages from 44 to 78 years. Methods Noncycloplegic refraction, year of birth, and highest educational level achieved were obtained for all participants. Myopia was defined as a mean spherical equivalent ≤−0.75 diopters. A random-effects meta-analysis of age-specific myopia prevalence was performed, with sequential analyses stratified by year of birth and highest level of educational attainment. Main Outcome Measures Variation in age-specific myopia prevalence for differing years of birth and educational level. Results There was a significant cohort effect for increasing myopia prevalence across more recent birth decades; age-standardized myopia prevalence increased from 17.8% (95% confidence interval [CI], 17.6–18.1) to 23.5% (95% CI, 23.2–23.7) in those born between 1910 and 1939 compared with 1940 and 1979 (P = 0.03). Education was significantly associated with myopia; for those completing primary, secondary, and higher education, the age-standardized prevalences were 25.4% (CI, 25.0–25.8), 29.1% (CI, 28.8–29.5), and 36.6% (CI, 36.1–37.2), respectively. Although more recent birth cohorts were more educated, this did not fully explain the cohort effect. Compared with the reference risk of participants born in the 1920s with only primary education, higher education or being born in the 1960s doubled the myopia prevalence ratio–2.43 (CI, 1.26–4.17) and 2.62 (CI, 1.31–5.00), respectively—whereas individuals born in the 1960s and completing higher education had approximately 4 times the reference risk: a prevalence ratio of 3.76 (CI, 2.21–6.57). Conclusions Myopia is becoming more common in Europe; although education levels have increased and are associated with myopia, higher education seems to be an additive rather than explanatory factor. Increasing levels of myopia carry significant clinical and economic implications, with more people at risk of the sight-threatening complications associated with high myopia. PMID:25983215

Increasing Prevalence of Myopia in Europe and the Impact of Education.

PubMed

Williams, Katie M; Bertelsen, Geir; Cumberland, Phillippa; Wolfram, Christian; Verhoeven, Virginie J M; Anastasopoulos, Eleftherios; Buitendijk, Gabriëlle H S; Cougnard-Grégoire, Audrey; Creuzot-Garcher, Catherine; Erke, Maja Gran; Hogg, Ruth; Höhn, René; Hysi, Pirro; Khawaja, Anthony P; Korobelnik, Jean-François; Ried, Janina; Vingerling, Johannes R; Bron, Alain; Dartigues, Jean-François; Fletcher, Astrid; Hofman, Albert; Kuijpers, Robert W A M; Luben, Robert N; Oxele, Konrad; Topouzis, Fotis; von Hanno, Therese; Mirshahi, Alireza; Foster, Paul J; van Duijn, Cornelia M; Pfeiffer, Norbert; Delcourt, Cécile; Klaver, Caroline C W; Rahi, Jugnoo; Hammond, Christopher J

2015-07-01

To investigate whether myopia is becoming more common across Europe and explore whether increasing education levels, an important environmental risk factor for myopia, might explain any temporal trend. Meta-analysis of population-based, cross-sectional studies from the European Eye Epidemiology (E(3)) Consortium. The E(3) Consortium is a collaborative network of epidemiological studies of common eye diseases in adults across Europe. Refractive data were available for 61 946 participants from 15 population-based studies performed between 1990 and 2013; participants had a range of median ages from 44 to 78 years. Noncycloplegic refraction, year of birth, and highest educational level achieved were obtained for all participants. Myopia was defined as a mean spherical equivalent ≤-0.75 diopters. A random-effects meta-analysis of age-specific myopia prevalence was performed, with sequential analyses stratified by year of birth and highest level of educational attainment. Variation in age-specific myopia prevalence for differing years of birth and educational level. There was a significant cohort effect for increasing myopia prevalence across more recent birth decades; age-standardized myopia prevalence increased from 17.8% (95% confidence interval [CI], 17.6-18.1) to 23.5% (95% CI, 23.2-23.7) in those born between 1910 and 1939 compared with 1940 and 1979 (P = 0.03). Education was significantly associated with myopia; for those completing primary, secondary, and higher education, the age-standardized prevalences were 25.4% (CI, 25.0-25.8), 29.1% (CI, 28.8-29.5), and 36.6% (CI, 36.1-37.2), respectively. Although more recent birth cohorts were more educated, this did not fully explain the cohort effect. Compared with the reference risk of participants born in the 1920s with only primary education, higher education or being born in the 1960s doubled the myopia prevalence ratio-2.43 (CI, 1.26-4.17) and 2.62 (CI, 1.31-5.00), respectively-whereas individuals born in the 1960s and completing higher education had approximately 4 times the reference risk: a prevalence ratio of 3.76 (CI, 2.21-6.57). Myopia is becoming more common in Europe; although education levels have increased and are associated with myopia, higher education seems to be an additive rather than explanatory factor. Increasing levels of myopia carry significant clinical and economic implications, with more people at risk of the sight-threatening complications associated with high myopia. Copyright © 2015 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

α-adrenergic agonist brimonidine control of experimentally induced myopia in guinea pigs: A pilot study

PubMed Central

Liu, Yan; Wang, Yuexin; Lv, Huibin; Jiang, Xiaodan; Zhang, Mingzhou

2017-01-01

Purpose To investigate the efficacy of α-adrenergic agonist brimonidine either alone or combined with pirenzepine for inhibiting progressing myopia in guinea pig lens–myopia-induced models. Methods Thirty-six guinea pigs were randomly divided into six groups: Group A received 2% pirenzepine, Group B received 0.2% brimonidine, Group C received 0.1% brimonidine, Group D received 2% pirenzepine + 0.2% brimonidine, Group E received 2% pirenzepine + 0.1% brimonidine, and Group F received the medium. Myopia was induced in the right eyes of all guinea pigs using polymethyl methacrylate (PMMA) lenses for 3 weeks. Eye drops were administered accordingly. Intraocular pressure was measured every day. Refractive error and axial length measurements were performed once a week. The enucleated eyeballs were removed for hematoxylin and eosin (H&E) and Van Gieson (VG) staining at the end of the study. Results The lens-induced myopia model was established after 3 weeks. Treatment with 0.1% brimonidine alone and 0.2% brimonidine alone was capable of inhibiting progressing myopia, as shown by the better refractive error (p=0.024; p=0.006) and shorter axial length (p=0.005; p=0.0017). Treatment with 0.1% brimonidine and 0.2% brimonidine combined with 2% pirenzepine was also effective in suppressing progressing refractive error (p=0.016; p=0.0006) and axial length (p=0.017; p=0.0004). The thickness of the sclera was kept stable in all groups except group F; the sclera was much thinner in the lens-induced myopia eyes compared to the control eyes. Conclusions Treatment with 0.1% brimonidine alone and 0.2% brimonidine alone, as well as combined with 2% pirenzepine, was effective in inhibiting progressing myopia. The result indicates that intraocular pressure elevation is possibly a promising mechanism and potential treatment for progressing myopia. PMID:29204068

A novel mutation in SLITRK6 causes deafness and myopia in a Moroccan family.

PubMed

Salime, Sara; Riahi, Zied; Elrharchi, Soukaina; Elkhattabi, Lamiae; Charoute, Hicham; Nahili, Halima; Rouba, Hassan; Kabine, Mostafa; Bonnet, Crystel; Petit, Christine; Barakat, Abdelhamid

2018-06-15

Deafness and myopia syndrome is characterized by moderate-profound, bilateral, congenital or prelingual deafness and high myopia. Autosomal recessive non-syndromic hearing loss is one of the most prevalent human genetic sensorineural defects. Myopia is by far the most common human eye disorder that is known to have a clear heritable component. The analysis of the two exons of SLITRK6 gene in a Moroccan family allowed us to identify a novel single deleterious mutation c.696delG, p.Trp232Cysfs*10 at homozygous state in the exon 2 of the SLITRK6, a gene reported to cause deafness and myopia in various populations. Copyright © 2018 Elsevier B.V. All rights reserved.

What factors are associated with myopia in young adults? A survey study in Taiwan Military Conscripts.

PubMed

Lee, Yin-Yang; Lo, Chung-Ting; Sheu, Shwu-Jiuan; Lin, Julia L

2013-02-05

We investigated the independent impact of potential risk factors on myopia in young adults. A survey study was conducted with male military conscripts aged 18 to 24 years between February 2010 and March 2011 in Taiwan. The participants were examined using non-cycloplegic autorefraction and biometry. The participants provided data about potential risk factors, including age, parental myopia, education, near work, outdoor activity, and urbanization. Myopia was defined as the mean spherical equivalent of the right eye of ≤ 0.5 diopters (D). Among 5145 eligible participants, 5048 (98.11%) had refraction and questionnaire data available; 2316 (45.88%) of these received axial length examination. The prevalence of myopia was 86.1% with a mean refractive error of -3.66 D (SD = 2.73) and an axial length of 25.40 mm (SD = 1.38). Older age, having myopic parents, higher education level, more time spent reading, nearer reading distance, less outdoor activity, and higher urbanization level were associated with myopia and longer axial length. More computer use was related to longer axial length. All risk factors associated with myopia also were predictors of high myopia (≤ -6.0 D), with the exception of outdoor activity. Finally, an interaction analysis showed shorter axial length was associated with more time spent outdoors only at high urbanization level. Older age, parental myopia, higher education level, more near work, less outdoor activity, and higher urbanization level were independent predictors of myopia. These data provided evidence to the multifactorial nature of myopia in young men in Taiwan.

[Indicators of general, cerebral, and regional hemodynamics in myopic schoolchildren aged 13-15 years].

PubMed

Iastrebtseva, T A; Chuprov, A D; Plotnikova, Iu A

2002-01-01

110 schoolchildren aged 13-15 years were examined. 24 of them had pseudomyopia and 6 patients myopia of various forms. A control group consisted of 38 children. Central hemodynamics was estimated by average dynamic pressure, cerebral hemodynamics--by rheoencephalography, regional hemodynamics--by dopplerography of the internal carotid and suprapubic arteries. It was found that with myopia progression, the average dynamic pressure positively comes down with reduction of reographic waves amplitude in rheogram. The blood flow rate in internal carotid and suprapubic arteries has no substantial impact on myopia course. Predisposition to arterial hypotension is a risk factor for myopia development and progression.

Dopamine signaling and myopia development: What are the key challenges.

PubMed

Zhou, Xiangtian; Pardue, Machelle T; Iuvone, P Michael; Qu, Jia

2017-11-01

In the face of an "epidemic" increase in myopia over the last decades and myopia prevalence predicted to reach 2.5 billion people by the end of this decade, there is an urgent need to develop effective and safe therapeutic interventions to slow down this "myopia booming" and prevent myopia-related complications and vision loss. Dopamine (DA) is an important neurotransmitter in the retina and mediates diverse functions including retina development, visual signaling, and refractive development. Inspired by the convergence of epidemiological and animal studies in support of the inverse relationship between outdoor activity and risk of developing myopia and by the close biological relationship between light exposure and dopamine release/signaling, we felt it is timely and important to critically review the role of DA in myopia development. This review will revisit several key points of evidence for and against DA mediating light control of myopia: 1) the causal role of extracellular retinal DA levels, 2) the mechanism and action of dopamine D1 and D2 receptors and 3) the roles of cellular/circuit retinal pathways. We examine the experiments that show causation by altering DA, DA receptors and visual pathways using pharmacological, transgenic, or visual environment approaches. Furthermore, we critically evaluate the safety issues of a DA-based treatment strategy and some approaches to address these issues. The review identifies the key questions and challenges in translating basic knowledge on DA signaling and myopia from animal studies into effective pharmacological treatments for myopia in children. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

[Study on relationship between outdoor activities and self-reported myopia among middle school students].

PubMed

Zhai, L L; Wu, X Y; Xu, S J; Wan, Y H; Zhang, S C; Xu, L; Liu, W; Ma, S S; Zhang, H; Tao, F B

2017-09-06

Objective: To examine the relationship between the prevalence of self-reported myopia and outdoor activities among middle school students and to explore the influence factors of the self-reported myopia. Methods: A total of 12 979 participants were recruited from junior and senior middle school students in in Shenzhen, Nanchang, Zhengzhou and Shenyang by random cluster sampling method between December 2015 and March 2016. All participants completed an anonymous questionnaire to collect the information of demographic characteristics, self-reported myopia, outdoor activities, etc. 12 603 out of 12 979 copies of questionnaire were valid. The prevalence of self-reported myopia was compared among middle school students with different characteristics. Logistic regression models were used to analyze the relationship between myopia and outdoor activities. Results: The prevalence of self-reported myopia among middle school students was 69.6% (8 766/12 603); which was separately 52.1% (1 216/2 335) in seventh grader, 61.6% (1 459/2 369) in eighth grader, 69.0%(1 470/2 129) in ninth grader, 80.0% (1 812/2 265) in freshmen, 79.4% (1 622/2 042) in sophomore, and 81.1%(1 187/1 463) in junior. The prevalence of self-reported myopia showed an increasing trend with the increase of grade (χ(2)=639.67, P< 0.001). The prevalence of self-reported myopia was separately 63.5%(4 927/7 756) in non-myopic parents group, 78.0%(2 664/3 415)in either myopic parent group, and 82.1%(1 175/1 432) in both myopic parents group(χ(2)=328.28, P< 0.001). Outdoor activities were associated with self-reported myopia. Binary logistic regression analysis showed that the risk of self-reported myopia was significantly increased by always staying at home in extracurricular time among the middle school students ( OR= 1.58, 95 %CI: 1.36-1.82). The risk of self-reported myopia were significantly decreased by always physical exercise and recreational activities after school among middle school students: the ORs were separately 0.67 (95 %CI: 0.57-0.78) for physical exercise and 0.77 (95 %CI: 0.64-0.92) for recreational activities. After stratified analysis by the parents' myopia status, in non-myopic parents group, exercise and recreational activities after school among middle school students decreased the risk of myopia: the ORs were separately 0.68 (95 %CI: 0.55-0.82) for physical exercise and 0.76 (95 %CI: 0.61-0.95) for recreational activities; in either myopic parent group, OR (95 %CI ) were separately 0.65 (0.47-0.90) and 0.68 (0.47-0.98). Conclusion: Outdoor activities was negatively associated with self-reported myopia among middle school students. However, the parents' myopia status may affect the protective effect.

Upregulation of regulator of G-protein signaling 2 in the sclera of a form deprivation myopic animal model

PubMed Central

Zou, Leilei; Liu, Rui; Zhang, Xiaohui; Chu, Renyuan; Dai, Jinhui; Zhou, Hao

2014-01-01

Purpose Scleral remodeling is an important mechanism underlying the development of myopia. Atropine, an antagonist of G protein-coupled muscarinic receptors, is currently used as an off-label treatment for myopia. Regulator of G-protein signaling 2 (RGS2) functions as an intracellular selective inhibitor of muscarinic receptors. In this study we measured scleral RGS2 expression and scleral remodeling in an animal model of myopia in the presence or absence of atropine treatment. Methods Guinea pigs were assigned to four groups: normal (free of form deprivation), form deprivation myopia (FDM) for 4 weeks, FDM treated with saline, and FDM treated with atropine. Biometric measurements were then performed. RGS2 expression levels and scleral remodeling, including scleral thickness and collagen type I expression, were compared among the four groups. Results Compared with normal eyes and contralateral control eyes, the FDM eyes had the most prominent changes in refraction, axial length, and scleral remodeling, indicating myopia. There was no significant difference between control and normal eyes. Hematoxylin and eosin staining showed that the scleral thickness was significantly thinner in the posterior pole region of FDM eyes compared to normal eyes. Real-time PCR and western blot analysis showed a significant decrease in posterior scleral collagen type I mRNA and protein expression in the FDM eyes compared to the normal eyes. The FDM eyes also had increased levels of RGS2 mRNA and protein expression in the sclera. Atropine treatment attenuated the FDM-induced changes in refraction, axial length, and scleral remodeling. Interestingly, atropine treatment significantly increased collagen type I mRNA expression but decreased RGS2 mRNA and protein expression in the sclera of the FDM eyes. Conclusions We identified a significant RGS2 upregulation and collagen type I downregulation in the sclera of FDM eyes, which could be partially attenuated by atropine treatment. Our data suggest that targeting dysregulated RGS2 may provide a novel strategy for development of therapeutic agents to suppress myopia progression. PMID:25018620

Ganglion cell-inner plexiform layer and retinal nerve fiber layer thickness according to myopia and optic disc area: a quantitative and three-dimensional analysis.

PubMed

Seo, Sam; Lee, Chong Eun; Jeong, Jae Hoon; Park, Ki Ho; Kim, Dong Myung; Jeoung, Jin Wook

2017-03-11

To determine the influences of myopia and optic disc size on ganglion cell-inner plexiform layer (GCIPL) and peripapillary retinal nerve fiber layer (RNFL) thickness profiles obtained by spectral domain optical coherence tomography (OCT). One hundred and sixty-eight eyes of 168 young myopic subjects were recruited and assigned to one of three groups according to their spherical equivalent (SE) values and optic disc area. All underwent Cirrus HD-OCT imaging. The influences of myopia and optic disc size on the GCIPL and RNFL thickness profiles were evaluated by multiple comparisons and linear regression analysis. Three-dimensional surface plots of GCIPL and RNFL thickness corresponding to different combinations of myopia and optic disc size were constructed. Each of the quadrant RNFL thicknesses and their overall average were significantly thinner in high myopia compared to low myopia, except for the temporal quadrant (all Ps ≤0.003). The average and all-sectors GCIPL were significantly thinner in high myopia than in moderate- and/or low-myopia (all Ps ≤0.002). The average OCT RNFL thickness was correlated significantly with SE (0.81 μm/diopter, P < 0.001), axial length (-1.44 μm/mm, P < 0.001), and optic disc area (5.35 μm/mm 2 , P < 0.001) by linear regression analysis. As for the OCT GCIPL parameters, average GCIPL thickness showed a significant correlation with SE (0.84 μm/diopter, P < 0.001) and axial length (-1.65 μm/mm, P < 0.001). There was no significant correlation of average GCIPL thickness with optic disc area. Three-dimensional curves showed that larger optic discs were associated with increased average RNFL thickness and that more-myopic eyes were associated with decreased average GCIPL and RNFL thickness. Myopia can significantly affect GCIPL and RNFL thickness profiles, and optic disc size has a significant influence on RNFL thickness. The current OCT maps employed in the evaluation of glaucoma should be analyzed in consideration of refractive status and optic disc size.

Molecular biology of myopia.

PubMed

Schaeffel, Frank; Simon, Perikles; Feldkaemper, Marita; Ohngemach, Sibylle; Williams, Robert W

2003-09-01

Experiments in animal models of myopia have emphasised the importance of visual input in emmetropisation but it is also evident that the development of human myopia is influenced to some degree by genetic factors. Molecular genetic approaches can help to identify both the genes involved in the control of ocular development and the potential targets for pharmacological intervention. This review covers a variety of techniques that are being used to study the molecular biology of myopia. In the first part, we describe techniques used to analyse visually induced changes in gene expression: Northern Blot, polymerase chain reaction (PCR) and real-time PCR to obtain semi-quantitative and quantitative measures of changes in transcription level of a known gene, differential display reverse transcription PCR (DD-RT-PCR) to search for new genes that are controlled by visual input, rapid amplification of 5' cDNA (5'-RACE) to extend the 5' end of sequences that are regulated by visual input, in situ hybridisation to localise the expression of a given gene in a tissue and oligonucleotide microarray assays to simultaneously test visually induced changes in thousands of transcripts in single experiments. In the second part, we describe techniques that are used to localise regions in the genome that contain genes that are involved in the control of eye growth and refractive errors in mice and humans. These include quantitative trait loci (QTL) mapping, exploiting experimental test crosses of mice and transmission disequilibrium tests (TDT) in humans to find chromosomal intervals that harbour genes involved in myopia development. We review several successful applications of this battery of techniques in myopia research.

Nitric Oxide (NO) Mediates the Inhibition of Form-Deprivation Myopia by Atropine in Chicks.

PubMed

Carr, Brittany J; Stell, William K

2016-12-05

Myopia is the most common childhood refractive disorder. Atropine inhibits myopia progression, but its mechanism is unknown. Here, we show that myopia-prevention by atropine requires production of nitric oxide (NO). Form-deprivation myopia (FDM) was induced in week-old chicks by diffusers over the right eye (OD); the left eye (OS) remained ungoggled. On post-goggling days 1, 3, and 5, OD received intravitreally 20 µL of phosphate-buffered saline (vehicle), or vehicle plus: NO source: L-arginine (L-Arg, 60-6,000 nmol) or sodium nitroprusside (SNP, 10-1,000 nmol); atropine (240 nmol); NO inhibitors: L-NIO or L-NMMA (6 nmol); negative controls: D-Arg (10 µmol) or D-NMMA (6 nmol); or atropine plus L-NIO, L-NMMA, or D-NMMA; OS received vehicle. On day 6 post-goggling, refractive error, axial length, equatorial diameter, and wet weight were measured. Vehicle-injected goggled eyes developed significant FDM. This was inhibited by L-Arg (ED50 = 400 nmol) or SNP (ED50 = 20 nmol), but not D-Arg. Higher-dose SNP, but not L-Arg, was toxic to retina/RPE. Atropine inhibited FDM as expected; adding NOS-inhibitors (L-NIO, L-NMMA) to atropine inhibited this effect dose-dependently, but adding D-NMMA did not. Equatorial diameter, wet weight, and metrics of control eyes were not affected by any treatment. In summary, intraocular NO inhibits myopia dose-dependently and is obligatory for inhibition of myopia by atropine.

Dissecting the genetic heterogeneity of myopia susceptibility in an Ashkenazi Jewish population using ordered subset analysis

PubMed Central

Simpson, Claire L.; Wojciechowski, Robert; Ibay, Grace; Stambolian, Dwight

2011-01-01

Purpose Despite many years of research, most of the genetic factors contributing to myopia development remain unknown. Genetic studies have pointed to a strong inherited component, but although many candidate regions have been implicated, few genes have been positively identified. Methods We have previously reported 2 genomewide linkage scans in a population of 63 highly aggregated Ashkenazi Jewish families that identified a locus on chromosome 22. Here we used ordered subset analysis (OSA), conditioned on non-parametric linkage to chromosome 22 to detect other chromosomal regions which had evidence of linkage to myopia in subsets of the families, but not the overall sample. Results Strong evidence of linkage to a 19-cM linkage interval with a peak OSA nonparametric allele-sharing logarithm-of-odds (LOD) score of 3.14 on 20p12-q11.1 (ΔLOD=2.39, empirical p=0.029) was identified in a subset of 20 families that also exhibited strong evidence of linkage to chromosome 22. One other locus also presented with suggestive LOD scores >2.0 on chromosome 11p14-q14 and one locus on chromosome 6q22-q24 had an OSA LOD score=1.76 (ΔLOD=1.65, empirical p=0.02). Conclusions The chromosome 6 and 20 loci are entirely novel and appear linked in a subset of families whose myopia is known to be linked to chromosome 22. The chromosome 11 locus overlaps with the known Myopia-7 (MYP7, OMIM 609256) locus. Using ordered subset analysis allows us to find additional loci linked to myopia in subsets of families, and underlines the complex genetic heterogeneity of myopia even in highly aggregated families and genetically isolated populations such as the Ashkenazi Jews. PMID:21738393

Eye growth and myopia development: Unifying theory and Matlab model.

PubMed

Hung, George K; Mahadas, Kausalendra; Mohammad, Faisal

2016-03-01

The aim of this article is to present an updated unifying theory of the mechanisms underlying eye growth and myopia development. A series of model simulation programs were developed to illustrate the mechanism of eye growth regulation and myopia development. Two fundamental processes are presumed to govern the relationship between physiological optics and eye growth: genetically pre-programmed signaling and blur feedback. Cornea/lens is considered to have only a genetically pre-programmed component, whereas eye growth is considered to have both a genetically pre-programmed and a blur feedback component. Moreover, based on the Incremental Retinal-Defocus Theory (IRDT), the rate of change of blur size provides the direction for blur-driven regulation. The various factors affecting eye growth are shown in 5 simulations: (1 - unregulated eye growth): blur feedback is rendered ineffective, as in the case of form deprivation, so there is only genetically pre-programmed eye growth, generally resulting in myopia; (2 - regulated eye growth): blur feedback regulation demonstrates the emmetropization process, with abnormally excessive or reduced eye growth leading to myopia and hyperopia, respectively; (3 - repeated near-far viewing): simulation of large-to-small change in blur size as seen in the accommodative stimulus/response function, and via IRDT as well as nearwork-induced transient myopia (NITM), leading to the development of myopia; (4 - neurochemical bulk flow and diffusion): release of dopamine from the inner plexiform layer of the retina, and the subsequent diffusion and relay of neurochemical cascade show that a decrease in dopamine results in a reduction of proteoglycan synthesis rate, which leads to myopia; (5 - Simulink model): model of genetically pre-programmed signaling and blur feedback components that allows for different input functions to simulate experimental manipulations that result in hyperopia, emmetropia, and myopia. These model simulation programs (available upon request) can provide a useful tutorial for the general scientist and serve as a quantitative tool for researchers in eye growth and myopia. Copyright © 2016 Elsevier Ltd. All rights reserved.

Involvement of GABA Transporters in Atropine-Treated Myopic Retina As Revealed by iTRAQ Quantitative Proteomics

PubMed Central

2015-01-01

Atropine, a muscarinic antagonist, is known to inhibit myopia progression in several animal models and humans. However, the mode of action is not established yet. In this study, we compared quantitative iTRAQ proteomic analysis in the retinas collected from control and lens-induced myopic (LIM) mouse eyes treated with atropine. The myopic group received a (−15D) spectacle lens over the right eye on postnatal day 10 with or without atropine eye drops starting on postnatal day 24. Axial length was measured by optical low coherence interferometry (OLCI), AC-Master, and refraction was measured by automated infrared photorefractor at postnatal 24, 38, and 52 days. Retinal tissue samples were pooled from six eyes for each group. The experiments were repeated twice, and technical replicates were also performed for liquid chromatography–tandem mass spectrometry (LC–MS/MS) analysis. MetaCore was used to perform protein profiling for pathway analysis. We identified a total of 3882 unique proteins with <1% FDR by analyzing the samples in replicates for two independent experiments. This is the largest number of mouse retina proteome reported to date. Thirty proteins were found to be up-regulated (ratio for myopia/control > global mean ratio + 1 standard deviation), and 28 proteins were down-regulated (ratio for myopia/control < global mean ratio - 1 standard deviation) in myopic eyes as compared with control retinas. Pathway analysis using MetaCore revealed regulation of γ-aminobutyric acid (GABA) levels in the myopic eyes. Detailed analysis of the quantitative proteomics data showed that the levels of GABA transporter 1 (GAT-1) were elevated in myopic retina and significantly reduced after atropine treatment. These results were further validated with immunohistochemistry and Western blot analysis. In conclusion, this study provides a comprehensive quantitative proteomic analysis of atropine-treated mouse retina and suggests the involvement of GABAergic signaling in the antimyopic effects of atropine in mouse eyes. The GABAergic transmission in the neural retina plays a pivotal role in the maintenance of axial eye growth in mammals. PMID:25211393

Serum Concentration of Zinc, Copper, Selenium, Manganese, and Cu/Zn Ratio in Children and Adolescents with Myopia.

PubMed

Fedor, Monika; Socha, Katarzyna; Urban, Beata; Soroczyńska, Jolanta; Matyskiela, Monika; Borawska, Maria H; Bakunowicz-Łazarczyk, Alina

2017-03-01

The purpose of the present study was the assessment of the serum concentration of antioxidant microelements-zinc, copper, selenium, manganese, and Cu/Zn ratio in children and adolescents with myopia. Eighty-three children were examined (mean age 14.36 ± 2.49 years) with myopia. The control group was 38 persons (mean age 12.89 ± 3.84 years). Each patient had complete eye examination. The serum concentration of zinc, copper, manganese, and selenium was determined by atomic absorption spectrometry. Cu/Zn ratio, which is the indicator of the oxidative stress, was also calculated. The average serum concentration of zinc in myopic patients was significantly lower (0.865 ± 0.221 mg L -1 ) in comparison to the control group (1.054 ± 0.174 mg L -1 ). There was significantly higher Cu/Zn ratio in myopic patients (1.196 ± 0.452) in comparison to that in the control group (0.992 ± 0.203). The average serum concentration of selenium in the study group was significantly lower (40.23 ± 12.07 μg L -1 ) compared with that in the control group (46.00 ± 12.25 μg L -1 ). There were no essential differences between serum concentration of copper and manganese in the study group and the control group. Low serum concentration of zinc and selenium in myopic children may imply an association between insufficiency of these antioxidant microelements and the development of the myopia and could be the indication for zinc and selenium supplementation in the prevention of myopia. Significantly, higher Cu/Zn ratio in the study group can suggest the relationship between myopia and oxidative stress.

Myopia Control with Bifocal Contact Lenses: A Randomized Clinical Trial.

PubMed

Aller, Thomas A; Liu, Maria; Wildsoet, Christine F

2016-04-01

Most studies have reported only minimal reductions in myopia progression with bifocal or progressive multifocal spectacles, although somewhat larger, although mostly still clinically insignificant, effects have been reported in children with nearpoint esophoria and/or accommodative dysfunctions. The CONTROL study was a 1-year, prospective, randomized, clinical trial of bifocal contact lenses for control of myopia in children with eso fixation disparities at near. Eighty-six myopic subjects, aged 8 to 18 years, were enrolled in the study after passing the screening examination. Of these, 79 completed lens assignment and 78 completed the study. The mean refractive error of these 79 subjects was -2.69 ± 1.40D (SD), and all had progressed by -0.50D or more since their last examination. All subjects also had eso fixation disparity at near. Subjects were randomly assigned to wear either Vistakon Acuvue 2 (single-vision soft contact lenses [SVSCLs]) or Vistakon Acuvue Bifocal (bifocal soft contact lenses [BFSCLs]). Bifocal adds were selected to neutralize the associated phoria. Treatment outcomes included cycloplegic autorefraction and axial length, assessed in terms of changes after 6 and 12 months of treatment from pretreatment baseline values. The BFSCLs significantly slowed myopia progression, with statistically significant differences between the treatment groups after 6 months. After 12 months of treatment, the SVSCL group had progressed by -0.79 ± 0.43D compared with -0.22 ± 0.34D for the BFSCL group (cycloplegic objective spherical equivalent, average of two eyes). Corresponding axial length changes were 0.24 ± 0.17 mm and 0.05 ± 0.14 mm, respectively. All of these differences were found to be statistically significant (unpaired t-tests, p < 0.001). The distance center bifocal contact lenses tested in this study achieved greater control over myopia progression and axial elongation (>70%) compared with most published results with multifocal spectacles. Further studies are warranted to identify the critical factors and mechanisms underlying this myopia control effect.

A Randomized Trial of Soft Multifocal Contact Lenses for Myopia Control: Baseline Data and Methods.

PubMed

Walline, Jeffrey J; Gaume Giannoni, Amber; Sinnott, Loraine T; Chandler, Moriah A; Huang, Juan; Mutti, Donald O; Jones-Jordan, Lisa A; Berntsen, David A

2017-09-01

The Bifocal Lenses In Nearsighted Kids (BLINK) study is the first soft multifocal contact lens myopia control study to compare add powers and measure peripheral refractive error in the vertical meridian, so it will provide important information about the potential mechanism of myopia control. The BLINK study is a National Eye Institute-sponsored, double-masked, randomized clinical trial to investigate the effects of soft multifocal contact lenses on myopia progression. This article describes the subjects' baseline characteristics and study methods. Subjects were 7 to 11 years old, had -0.75 to -5.00 spherical component and less than 1.00 diopter (D) astigmatism, and had 20/25 or better logMAR distance visual acuity with manifest refraction in each eye and with +2.50-D add soft bifocal contact lenses on both eyes. Children were randomly assigned to wear Biofinity single-vision, Biofinity Multifocal "D" with a +1.50-D add power, or Biofinity Multifocal "D" with a +2.50-D add power contact lenses. We examined 443 subjects at the baseline visits, and 294 (66.4%) subjects were enrolled. Of the enrolled subjects, 177 (60.2%) were female, and 200 (68%) were white. The mean (± SD) age was 10.3 ± 1.2 years, and 117 (39.8%) of the eligible subjects were younger than 10 years. The mean spherical equivalent refractive error, measured by cycloplegic autorefraction was -2.39 ± 1.00 D. The best-corrected binocular logMAR visual acuity with glasses was +0.01 ± 0.06 (20/21) at distance and -0.03 ± 0.08 (20/18) at near. The BLINK study subjects are similar to patients who would routinely be eligible for myopia control in practice, so the results will provide clinical information about soft bifocal contact lens myopia control as well as information about the mechanism of the treatment effect, if one occurs.

Pineal control of the dopamine D2-receptor gene and dopamine release in the retina of the chicken and their possible relation to growth rhythms of the eye.

PubMed

Ohngemach, S; Feldkaemper, M; Schaeffel, F

2001-09-01

Retinal dopamine (DA) and the DA D2-receptor have been implicated in the development of "deprivation myopia", induced by frosted eye occluders. We have studied the changes in D2-mediated dopaminergic transmission in the retina, their possible relations to eye growth rhythms and myopia, and their control by the pineal gland. (1) We found that the sensitivity of eye growth to retinal image degradation varied over the day. Intermittent periods of normal vision inhibited deprivation myopia more if they occurred in the evening than in the morning. (2) Diurnal growth rhythms in both eyes interacted even though it was previously shown that both deprivation myopia and the accompanying changes in retinal DA release can be monocularly induced. (3) The D2-receptor mRNA concentration in the retina showed no systemic diurnal changes and was not affected by deprivation myopia, but was increased after 2 days in darkness. Since DA release varies over the day, the gain of dopaminergic transmission may also vary, which could explain the observation described in (1) above. (4) Depletion of retinal DA by intravitreal application of reserpine, which lowers DA content severely, had little effect on D2-receptor mRNA concentration. (5) Selective illumination of the pineal gland reduced the D2-receptor mRNA content in the retina to a similar level to full illumination, indicating that the pineal gland controls the D2-receptor mRNA content in the retina. The pineal also controlled DA release in the retina. These results show that the pineal has a surprisingly large influence on both the retinal DA receptor gene transcription and DA release. It can probably control the gain of dopaminergic transmission in the retina and deprivation myopia and mediate the interactions of the growth rhythms in both eyes.

The Association between Near Work Activities and Myopia in Children—A Systematic Review and Meta-Analysis

PubMed Central

2015-01-01

Myopia has a multifactorial etiology, although environmental factors are predominant in determining its current patterns. Currently, associations between near work activities and myopia have not been consistently observed. Therefore, we performed a systematic review to quantify the effect of near work activities on myopia in children. Relevant articles published between 1989 and 2014 were identified in MEDLINE, Embase, and the Cochrane Library, and the citation lists were reviewed. Twelve cohort studies and 15 cross-sectional studies were included (25,025 children aged between 6 and 18 years). The I 2 statistic was used to assess heterogeneity. Study-level data were pooled using a random-effects model or a fixed-effects model (when less than 5 studies were included). We found that more time spent on near work activities was associated with higher odds of myopia (odds ratio [OR] = 1.14; 95% confidence interval [CI] = 1.08–1.20) and that the odds of myopia increased by 2% (OR:1.02; 95% CI = 1.01–1.03) for every one diopter-hour (hr) more of near work per week. Therefore, the development of a strategy to reduce the impact of near work on myopia would be important for preventing myopia in children. PMID:26485393

Exome Sequence Analysis of 14 Families With High Myopia.

PubMed

Kloss, Bethany A; Tompson, Stuart W; Whisenhunt, Kristina N; Quow, Krystina L; Huang, Samuel J; Pavelec, Derek M; Rosenberg, Thomas; Young, Terri L

2017-04-01

To identify causal gene mutations in 14 families with autosomal dominant (AD) high myopia using exome sequencing. Select individuals from 14 large Caucasian families with high myopia were exome sequenced. Gene variants were filtered to identify potential pathogenic changes. Sanger sequencing was used to confirm variants in original DNA, and to test for disease cosegregation in additional family members. Candidate genes and chromosomal loci previously associated with myopic refractive error and its endophenotypes were comprehensively screened. In 14 high myopia families, we identified 73 rare and 31 novel gene variants as candidates for pathogenicity. In seven of these families, two of the novel and eight of the rare variants were within known myopia loci. A total of 104 heterozygous nonsynonymous rare variants in 104 genes were identified in 10 out of 14 probands. Each variant cosegregated with affection status. No rare variants were identified in genes known to cause myopia or in genes closest to published genome-wide association study association signals for refractive error or its endophenotypes. Whole exome sequencing was performed to determine gene variants implicated in the pathogenesis of AD high myopia. This study provides new genes for consideration in the pathogenesis of high myopia, and may aid in the development of genetic profiling of those at greatest risk for attendant ocular morbidities of this disorder.

The Association between Near Work Activities and Myopia in Children-A Systematic Review and Meta-Analysis.

PubMed

Huang, Hsiu-Mei; Chang, Dolly Shuo-Teh; Wu, Pei-Chang

2015-01-01

Myopia has a multifactorial etiology, although environmental factors are predominant in determining its current patterns. Currently, associations between near work activities and myopia have not been consistently observed. Therefore, we performed a systematic review to quantify the effect of near work activities on myopia in children. Relevant articles published between 1989 and 2014 were identified in MEDLINE, Embase, and the Cochrane Library, and the citation lists were reviewed. Twelve cohort studies and 15 cross-sectional studies were included (25,025 children aged between 6 and 18 years). The I2 statistic was used to assess heterogeneity. Study-level data were pooled using a random-effects model or a fixed-effects model (when less than 5 studies were included). We found that more time spent on near work activities was associated with higher odds of myopia (odds ratio [OR] = 1.14; 95% confidence interval [CI] = 1.08-1.20) and that the odds of myopia increased by 2% (OR:1.02; 95% CI = 1.01-1.03) for every one diopter-hour (hr) more of near work per week. Therefore, the development of a strategy to reduce the impact of near work on myopia would be important for preventing myopia in children.

Reduced Scleral TIMP-2 Expression Is Associated With Myopia Development: TIMP-2 Supplementation Stabilizes Scleral Biomarkers of Myopia and Limits Myopia Development.

PubMed

Liu, Hsin-Hua; Kenning, Megan S; Jobling, Andrew I; McBrien, Neville A; Gentle, Alex

2017-04-01

The purpose of this study was to determine the endogenous regulation pattern of tissue inhibitor of metalloproteinase-2 (TIMP-2) in the tree shrew sclera during myopia development and investigate the capacity of exogenous TIMP-2 to inhibit matrix metalloproteinase-2 (MMP-2) in vitro and both scleral collagen degradation and myopia development in vivo. TIMP-2 expression in the sclera during myopia development was assessed using polymerase chain reaction. In vitro TIMP-2 inhibition of MMP-2 was investigated using a gelatinase activity plate assay and zymography. Tree shrews were injected with a collagen precursor before undergoing monocular form deprivation and concurrent daily subconjunctival injections of either TIMP-2 or vehicle to the form-deprived eye. In vivo ocular biometry changes were monitored, and scleral tissue was collected after 12 days and assayed for collagen degradation. The development of myopia was associated with a mean reduction in TIMP-2 mRNA expression after 5 days of form deprivation (P < 0.01). Both activation and activity of MMP-2 were inhibited by TIMP-2 with an IC50 of 10 to 20 and 2 nM, respectively. In vivo exogenous addition of TIMP-2 significantly reduced myopia development (P < 0.01), due to reduced vitreous chamber elongation (P < 0.01). In vivo TIMP-2 treatment also significantly inhibited posterior scleral collagen degradation relative to vehicle-treated eyes (P < 0.01), with levels similar to those in control eyes. Myopia development in mammals is associated with reduced expression of TIMP-2, which contributes to increased degradative activity in the sclera. It follows that replenishment of this TIMP-2 significantly reduced the rate of both scleral collagen degradation and myopia development.

Ethnic variations in myopia and ocular biometry among adults in a rural community in China: the Yunnan minority eye studies.

PubMed

Pan, Chen-Wei; Chen, Qin; Sheng, Xun; Li, Jun; Niu, Zhiqiang; Zhou, Hua; Wei, Tao; Yuan, Yuansheng; Zhong, Hua

2015-05-01

To determine the prevalence of myopia and ocular biometry in population-based samples of ethnic Yi and Han people living in an inland rural community in China. A random cluster sampling strategy was used to select ethnic Han and Yi adults aged 50 years or older living in Yunnan. Refractive error was determined by subjective refraction and ocular biometric parameters, including axial length (AL), anterior chamber depth (ACD), vitreous chamber depth (VCD), and lens thickness (LT), which were measured using an Echoscan. Adults of Yi ethnicity had lower prevalence of myopia (10.3% vs. 8.1%; P = 0.02) and high myopia (2.3% vs. 1.6%; P = 0.10) than their counterparts of Han ethnicity. The prevalence of myopia increased with age (P for trend < 0.05), whereas the mean AL did not differ significantly among age groups in both ethnic groups (both P for trend > 0.05). In multivariate analysis, time spent outdoors was associated with myopia (P = 0.003) and AL (P < 0.001) but not high myopia (P = 0.33). No interaction effect was detected between ethnicity and other risk factors on myopia (all P > 0.05). Adjustment for lens nuclear opacity score reduced the excess prevalence of myopia in Han ethnicity by 37.5%. There was little evidence showing that ethnic disparities existed in the prevalence and risk factors between the major and minor ethnic groups living in the same communities in rural China. The "cohort effect" on myopia observed in many other populations was not seen in this study.

Relations between age, weight, refractive error and eye shape by computerized tomography in children.

PubMed

Song, Ha Tae; Kim, Young Jun; Lee, Soo Jung; Moon, Yeon Sung

2007-09-01

To investigate relationships between age, weight, refractive error, and morphologic changes in children's eyes by computerized tomography (CT). Of the 772 eyes of 386 patients under the age of 20 years, who visited our Department of Ophthalmology between January 2005 to August 2006 and underwent CT of the orbit, 406 eyes of 354 patients with clear CT images and normal eyeball contour were enrolled in the present retrospective study. The axial lengths, widths, horizontal and vertical lengths, refractive errors, and body weight of eyes were measured, and relationship between these parameters were investigated. Axial length was found to correlate significantly with eye width (r=0.914), and in emmetropic eyes and myopic eyes, axial lengths and widths were found to increase as age and body weight increased. Axial lengths increased rapidly until age 10, and then increased slowly. In emmetropic eyes, widths/axial lengths increased with age, but in myopic eyes these decreased as age or severity of myopia increased. Moreover, as age increased, the myopic population and severity also increased. The axial length was longer in case of myopia compared to emmetropia in all age groups and there was almost no difference in the increase rate of axial length by the age of myopia and emmetropia. However, the width was wider in case of myopia compared to emmetropia in all age groups and the increase rate of width in myopia by age was smaller than that of emmetropia. Myopia showed decreasing rate of width/axial length with increase of age, from 1.004 in 5 years to 0.971 in 20 years. However, emmetropia showed increasing rate of width/axial length with increase of age, from 0.990 in 5 years to 1.006 in 20 years.

Relations between Age, Weight, Refractive Error and Eye Shape by Computerized Tomography in Children

PubMed Central

Song, Ha Tae; Kim, Young Jun; Lee, Soo Jung

2007-01-01

Purpose To investigate relationships between age, weight, refractive error, and morphologic changes in children's eyes by computerized tomography (CT). Methods Of the 772 eyes of 386 patients under the age of 20 years, who visited our Department of Ophthalmology between January 2005 to August 2006 and underwent CT of the orbit, 406 eyes of 354 patients with clear CT images and normal eyeball contour were enrolled in the present retrospective study. The axial lengths, widths, horizontal and vertical lengths, refractive errors, and body weight of eyes were measured, and relationship between these parameters were investigated. Results Axial length was found to correlate significantly with eye width (r=0.914), and in emmetropic eyes and myopic eyes, axial lengths and widths were found to increase as age and body weight increased. Axial lengths increased rapidly until age 10, and then increased slowly. In emmetropic eyes, widths / axial lengths increased with age, but in myopic eyes these decreased as age or severity of myopia increased. Moreover, as age increased, the myopic population and severity also increased. Conclusions The axial length was longer in case of myopia compared to emmetropia in all age groups and there was almost no difference in the increase rate of axial length by the age of myopia and emmetropia. However, the width was wider in case of myopia compared to emmetropia in all age groups and the increase rate of width in myopia by age was smaller than that of emmetropia. Myopia showed decreasing rate of width/axial length with increase of age, from 1.004 in 5 years to 0.971 in 20 years. However, emmetropia showed increasing rate of width/axial length with increase of age, from 0.990 in 5 years to 1.006 in 20 years. PMID:17804923

Myopia and personality: the genes in myopia (GEM) personality study.

PubMed

van de Berg, Robert; Dirani, Mohamed; Chen, Christine Y; Haslam, Nicholas; Baird, Paul N

2008-03-01

A long-held view among the medical and broader community is that people who are short-sighted (myopic persons) have distinctive personality characteristics such as introversion and conscientiousness. However, existing research on this question is flawed, and its findings are inconsistent. The authors therefore aimed to determine whether myopia and personality are associated. The authors examined twins recruited through the Australian Twin Registry and a clinical-based family sample through a proband from a Melbourne Excimer Laser Clinic. There was no relation between family members and twins recruited in our study. Each individual underwent a full eye examination, completed a standard medical and general questionnaire, and was administered a five-factor model International Personality Item Pool (IPIP) inventory (Openness, Conscientiousness, Extroversion, Agreeableness, Neuroticism). Myopia was defined as worse than or equal to -0.50 (DS) spherical equivalent in the eye with the least refractive error. Data from 633 individual twins aged 18 to 83 years (mean, 53.04 years) and 278 family members aged 11 to 90 years (mean, 49.84 years) were analyzed. Prevalence of myopia was 35.7% for twins and 47.6% for family members. Mean spherical equivalent was +0.13 DS (95% CI, +/-0.16) for twins and -1.13 DS (95% CI, +/-0.25) for family members. Correlation and regression results for personality for both sample cohorts after multivariate analysis did not support the view that myopic persons are introverted or conscientious; however, there was a significant but small association between myopia and Agreeableness (r = 0.08, P < 0.05). In multivariate analysis with age, sex, education, and the five personality factors entered as predictors, Openness was the only significant personality predictor of myopia in both samples. This is the first multivariate study to assess links between personality and myopia using the IPIP. The long-held view that myopic persons are introverted and conscientious may reflect intelligence-related stereotypes rather than real correlations. Furthermore, the predictive characteristic of intellect, subsumed in Openness, appeared to be representative of a previously reported link between intellective abilities (IQ) and myopia rather than personality and myopia.

US productivity slowdown: a case of statistical myopia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Darby, M.R.

1984-06-01

The author argues that the productivity panic is based upon statistical myopia, and that a careful analysis within the perspective of the entire 20th century discloses no substantial variation in what is described as growth in total factor productivity or technical progress. He finds no substantial variations in trend growth rates of private labor productivity since 1900 if reasonable adjustments are made for the effects of demographic trends on the average quality of labor. Even if one were to ignore the effects of demographic shifts, the measured growth rates of productivity, total private hours, and private employment have essentially themore » same values in 1956-79 as for 1900-29. Some of the primary data base for the paper appears in the appendix. 39 references, 3 figures, 9 tables.« less

Single-step transepithelial photorefractive keratectomy in myopia and astigmatism: 18-month follow-up.

PubMed

Adib-Moghaddam, Soheil; Soleyman-Jahi, Saeed; Salmanian, Bahram; Omidvari, Amir-Houshang; Adili-Aghdam, Fatemeh; Noorizadeh, Farsad; Eslani, Medi

2016-11-01

To evaluate the long-term quantitative and qualitative optical outcomes of 1-step transepithelial photorefractive keratectomy (PRK) to correct myopia and astigmatism. Bina Eye Hospital, Tehran, Iran. Prospective interventional case series. Eyes with myopia with or without astigmatism were evaluated. One-step transepithelial PRK was performed with an aberration-free aspheric optimized profile and the Amaris 500 laser. Eighteen-month follow-up results for refraction, visual acuities, vector analysis, higher-order aberrations, contrast sensitivity, postoperative pain, and haze grade were assessed. The study enrolled 146 eyes (74 patients). At the end of follow-up, 93.84% of eyes had an uncorrected distance visual acuity of 20/20 or better and 97.94% of eyes were within ±0.5 diopter of the targeted spherical refraction. On vector analysis, the mean correction index value was close to 1 and the mean index of success and magnitude of error values were close to 0. The achieved correction vector was on an axis counterclockwise to the axis of the intended correction. Photopic and mesopic contrast sensitivities and ocular and corneal spherical, cylindrical, and corneal coma aberrations significantly improved (all P < .001). A slight amount of trefoil aberration was induced (P < .001, ocular aberration; P < .01, corneal aberration). No eye lost more than 1 line of corrected distance visual acuity. No eye had a haze grade of 2+ degrees or higher throughout the follow-up. Eighteen-month results indicate the efficacy and safety of transepithelial PRK to correct myopia and astigmatism. It improved refraction and quality of vision. None of the authors has a financial or proprietary interest in any material or method mentioned. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

A Bioengineering Approach to Myopia Control Tested in a Guinea Pig Model

PubMed Central

Garcia, Mariana B.; Jha, Amit K.; Healy, Kevin E.; Wildsoet, Christine F.

2017-01-01

Purpose To investigate the biocompatibility of an injectable hydrogel and its ability to control myopia progression in guinea pigs. Methods The study used a hydrogel synthesized from acrylated hyaluronic acid with a conjugated cell-binding peptide and enzymatically degradable crosslinker. Seven-day-old guinea pigs were first form deprived (FD) with diffusers for 1 week. One group was kept as an FD-only control; two groups received a sub-Tenon's capsule injection of either hydrogel or buffer (sham surgery) at the posterior pole of the eye. Form deprivation treatments were then continued for 3 additional weeks. Treatment effects were evaluated in terms of ocular axial length and refractive error. Safety was evaluated via intraocular pressure (IOP), visual acuity, flash electroretinograms (ERG), and histology. Results Both hydrogel and sham surgery groups showed significantly reduced axial elongation and myopia progression compared to the FD-only group. For axial lengths, net changes in interocular difference (treated minus control) were 0.04 ± 0.06, 0.02 ± 0.09, and 0.24 ± 0.08 mm for hydrogel, sham, and FD-only groups, respectively (P = 0.0006). Intraocular pressures, visual acuities, and ERGs of treated eyes were not significantly different from contralateral controls. Extensive cell migration into the implants was evident. Both surgery groups showed noticeable Tenon's capsule thickening. Conclusions Sub-Tenon's capsule injections of both hydrogel and buffer inhibited myopia progression, with no adverse effects on ocular health. The latter unexpected effect warrants further investigation as a potential novel myopia control therapy. That the hydrogel implant supported significant cell infiltration offers further proof of its biocompatibility, with potential application as a tool for drug and cell delivery. PMID:28358959

Topographic analyses of shape of eyes with pathologic myopia by high-resolution three-dimensional magnetic resonance imaging.

PubMed

Moriyama, Muka; Ohno-Matsui, Kyoko; Hayashi, Kengo; Shimada, Noriaki; Yoshida, Takeshi; Tokoro, Takashi; Morita, Ikuo

2011-08-01

To analyze the topography of human eyes with pathologic myopia by high-resolution magnetic resonance imaging (MRI) with volume rendering of the acquired images. Observational case series. Eighty-six eyes of 44 patients with high myopia (refractive error ≥-8.00 diopters [D] or axial length >26.5 mm) were studied. Forty emmetropic eyes were examined as controls. The participants were examined with an MRI scanner (Signa HDxt 1.5T, GE Healthcare, Waukesha, WI), and T(2)-weighted cubes were obtained. Volume renderings of the images from high-resolution 3-dimensional (3D) data were done by computer workstation. The margins of globes were then identified semiautomatically by the signal intensity, and the tissues outside the globes were removed. The 3D topographic characteristic of the globes and the distribution of the 4 distinct shapes of globes according to the symmetry and the radius of curvature of the contour of the posterior segment: the barrel, cylindric, nasally distorted, and temporally distorted types. In 69.8% of the patients with bilateral high myopia, both eyes had the same ocular shape. The most protruded part of the globe existed along the central sagittal axis in 78.3% of eyes and was slightly inferior to the central axis in the remaining eyes. In 38 of 68 eyes (55.9%) with bilateral pathologic myopia, multiple protrusions were observed. The eyes with 2 protrusions were subdivided into those with nasal protrusions and those with temporal protrusions. The eyes with 3 protrusions were subdivided into nasal, temporal superior, and temporal inferior protrusions. The eyes with visual field defects that could not be explained by myopic fundus lesions significantly more frequently had a temporally distorted shape. Eyes with ≥2 protrusions had myopic chorioretinal atrophy significantly more frequently than eyes with ≤1 protrusion. Our results demonstrate that it is possible to obtain a complete topographic image of human eyes by high-resolution MRI with volume-rendering techniques. The results showed that there are different ocular shapes in eyes with pathologic myopia, and that the difference in the ocular shape is correlated with the development of vision-threatening conditions in eyes with pathologic myopia. The author(s) have no proprietary or commercial interest in any materials discussed in this article. Copyright © 2011 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Development of Experimental Myopia in Chicks in a Natural Environment

PubMed Central

Stone, Richard A.; Cohen, Yuval; McGlinn, Alice M.; Davison, Sherrill; Casavant, Susan; Shaffer, James; Khurana, Tejvir S.; Pardue, Machelle T.; Iuvone, P. Michael

2016-01-01

Purpose The hypothesis that outdoor exposure might protect against myopia has generated much interest, although available data find only modest clinical efficacy. We tested the effect of outdoor rearing on form-deprivation myopia in chicks, a myopia model markedly inhibited by high-intensity indoor laboratory lighting. Methods Unilaterally goggled cohorts of White Leghorn chicks were maintained in a species-appropriate, outdoor rural setting during daylight hours to the extent permitted by weather. Control chicks were reared indoors with incandescent lighting. Besides ocular refraction and ultrasound, we determined dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) content in retina and vitreous and measured mRNA expression levels of selected clock and circadian rhythm-related genes in the retina/RPE. Results Myopia developed in the goggled eyes of all cohorts. Whereas outdoor rearing lessened myopia by 44% at 4 days, a protective effect was no longer evident at 11 days. Outdoor rearing had no consistent effect on retinal or vitreous content of dopamine or DOPAC. Conforming to prior data on form-deprivation myopia, retina and vitreous levels of DOPAC were reduced in goggled eyes. Compared with contralateral eyes, the retinal expression of clock and circadian rhythm-related genes was modestly altered in myopic eyes of chicks reared indoors or outdoors. Conclusions Outdoor rearing of chicks induces only a partial decrease of goggle-induced myopia that is not maintained, without evidence that retinal dopamine metabolism accounts for the partial myopia inhibition under these outdoor conditions. Although modest, alterations in retinal gene expression suggest that studying circadian signals might be informative for understanding refractive mechanisms. PMID:27618415

Prevalence of refractive error in Europe: the European Eye Epidemiology (E(3)) Consortium.

PubMed

Williams, Katie M; Verhoeven, Virginie J M; Cumberland, Phillippa; Bertelsen, Geir; Wolfram, Christian; Buitendijk, Gabriëlle H S; Hofman, Albert; van Duijn, Cornelia M; Vingerling, Johannes R; Kuijpers, Robert W A M; Höhn, René; Mirshahi, Alireza; Khawaja, Anthony P; Luben, Robert N; Erke, Maja Gran; von Hanno, Therese; Mahroo, Omar; Hogg, Ruth; Gieger, Christian; Cougnard-Grégoire, Audrey; Anastasopoulos, Eleftherios; Bron, Alain; Dartigues, Jean-François; Korobelnik, Jean-François; Creuzot-Garcher, Catherine; Topouzis, Fotis; Delcourt, Cécile; Rahi, Jugnoo; Meitinger, Thomas; Fletcher, Astrid; Foster, Paul J; Pfeiffer, Norbert; Klaver, Caroline C W; Hammond, Christopher J

2015-04-01

To estimate the prevalence of refractive error in adults across Europe. Refractive data (mean spherical equivalent) collected between 1990 and 2013 from fifteen population-based cohort and cross-sectional studies of the European Eye Epidemiology (E(3)) Consortium were combined in a random effects meta-analysis stratified by 5-year age intervals and gender. Participants were excluded if they were identified as having had cataract surgery, retinal detachment, refractive surgery or other factors that might influence refraction. Estimates of refractive error prevalence were obtained including the following classifications: myopia ≤-0.75 diopters (D), high myopia ≤-6D, hyperopia ≥1D and astigmatism ≥1D. Meta-analysis of refractive error was performed for 61,946 individuals from fifteen studies with median age ranging from 44 to 81 and minimal ethnic variation (98 % European ancestry). The age-standardised prevalences (using the 2010 European Standard Population, limited to those ≥25 and <90 years old) were: myopia 30.6 % [95 % confidence interval (CI) 30.4-30.9], high myopia 2.7 % (95 % CI 2.69-2.73), hyperopia 25.2 % (95 % CI 25.0-25.4) and astigmatism 23.9 % (95 % CI 23.7-24.1). Age-specific estimates revealed a high prevalence of myopia in younger participants [47.2 % (CI 41.8-52.5) in 25-29 years-olds]. Refractive error affects just over a half of European adults. The greatest burden of refractive error is due to myopia, with high prevalence rates in young adults. Using the 2010 European population estimates, we estimate there are 227.2 million people with myopia across Europe.

[Association between time spent on physical exercise, sleep, homework and suspected myopia among students].

PubMed

Xu, S J; Wan, Y H; Xu, Z H; Zhang, H; Xu, L; Wang, B; Tao, F B

2016-02-01

To investigate the prevalence of suspected myopia among students and to examine the relationship between time spent on physical exercise, sleep, homework and suspected myopia. A total of 8 030 primary and secondary school students from 4(th) to 12(th) grades were selected from the National Student Constitution and Health Survey (NSCHS) in Anhui province in 2014. Time spent on exercise, sleep and homework per day were collected using a self-administrated questionnaire. Visual acuity was examined using the Standard Logarithmic Visual Acuity Chart. The overall prevalence of suspected myopia was 69.03%. Prevalence rates of suspected myopia appeared higher in girls, in urban students, with the highest in the 16 to 18 year-old groups. RESULTS from the multiple logistic regression analysis showed that the amount of time spent on physical exercise, sleep and homework per day were all significantly associated with suspected myopia. Suspected myopia was associated with longer time on physical exercise among students aged 8 to 12 years (OR=0.80, 95%CI: 0.64-0.99), and longer sleep time among students in the age groups of 13 to 15 years and 16 to 18 years (OR=0.73, 95% CI: 0.56-0.94;OR=0.38, 95% CI: 0.21-0.68, respectively). Longer time spent on homework significantly increased the risk of suspected myopia among students in the age groups of 8 to 12 years and 13 to 15 years (OR=1.41, 95%CI: 1.11-1.79; OR=1.74, 95% CI: 1.36-2.23, respectively). Suspected myopia appeared common among students. Comprehensive intervention programs focusing on sufficient physical exercise and sleep but less homework might help to prevent myopia among students at different ages.

Advanced myopia, prevalence and incidence analysis.

PubMed

Greene, Peter R; Greene, Judith M

2018-04-01

Various high-percentage high-incidence medical conditions, acute or chronic, start at a particular age of onset t1 (years), accumulate or progress rapidly, with a system time constant t0 (years), typically from 1 week to 5 years, and then level off at a plateau level [Formula: see text], ultimately affecting 10-95% of the population. This report investigates the prevalence and incidence functions for myopia and high myopia as a function of age. Fundamental prevalence versus time and incidence versus time results allow continuous prediction of myopia and high myopia population fractions as a function of age. This is a retrospective study. Nine reports are calculated with N = 444,600 subjects. There were no interventions other than usual regular eye examinations and subsequent indicated refraction change. The main result is continuous prediction of myopia prevalence-time data along with incidence rate data (%/year), age of onset (years), system plateau level, and system time constant (years). These parameters apply to progressive myopia and high myopia (R < -6 D), useful over several decades. The primary finding of this research is that the prevalence ratio of high myopes (R < -6.0 D) to common myopes is expected to increase from 15% entering college to 45% or more after college and graduate school. These statistics are particularly relevant to the many years of study required by M.D., Ph.D., and M.D./Ph.D. programs.

Incremental retinal-defocus theory of myopia development--schematic analysis and computer simulation.

PubMed

Hung, George K; Ciuffreda, Kenneth J

2007-07-01

Previous theories of myopia development involved subtle and complex processes such as the sensing and analyzing of chromatic aberration, spherical aberration, spatial gradient of blur, or spatial frequency content of the retinal image, but they have not been able to explain satisfactorily the diverse experimental results reported in the literature. On the other hand, our newly proposed incremental retinal-defocus theory (IRDT) has been able to explain all of these results. This theory is based on a relatively simple and direct mechanism for the regulation of ocular growth. It states that a time-averaged decrease in retinal-image defocus area decreases the rate of release of retinal neuromodulators, which decreases the rate of retinal proteoglycan synthesis with an associated decrease in scleral structural integrity. This increases the rate of scleral growth, and in turn the eye's axial length, which leads to myopia. Our schematic analysis has provided a clear explanation for the eye's ability to grow in the appropriate direction under a wide range of experimental conditions. In addition, the theory has been able to explain how repeated cycles of nearwork-induced transient myopia leads to repeated periods of decreased retinal-image defocus, whose cumulative effect over an extended period of time results in an increase in axial growth that leads to permanent myopia. Thus, this unifying theory forms the basis for understanding the underlying retinal and scleral mechanisms of myopia development.

Effects of Topical Latanoprost on Intraocular Pressure and Myopia Progression in Young Guinea Pigs

PubMed Central

El-Nimri, Nevin W.; Wildsoet, Christine F.

2018-01-01

Purpose To determine whether latanoprost, a prostaglandin analog proven to be very effective in reducing intraocular pressure (IOP) in humans, can also slow myopia progression in the guinea pig form deprivation (FD) model. Methods Two-week-old pigmented guinea pigs underwent monocular FD and daily topical latanoprost (0.005%, n = 10) or artificial tears (control, n = 10) starting 1 week after the initiation of FD, with all treatments continuing for a further 9 weeks. Tonometry, retinoscopy, and high-frequency A-scan ultrasonography were used to monitor IOP, refractive error, and ocular axial dimensions, respectively. Results Latanoprost significantly reduced IOP and slowed myopia progression. Mean interocular IOP differences (±SEM) recorded at baseline and week 10 were −0.30 ± 0.51 and 1.80 ± 1.16 mm Hg (P = 0.525) for the control group and 0.07 ± 0.35 and −5.17 ± 0.96 mm Hg (P < 0.001) for the latanoprost group. Equivalent interocular differences for optical axial length at baseline and week 10 were 0.00 ± 0.015 and 0.29 ± 0.04 mm (P < 0.001; control) and 0.02 ± 0.02 and 0.06 ± 0.02 mm (P = 0.202; latanoprost), and for refractive error were +0.025 ± 0.36 and −8.2 ± 0.71 diopter (D) (P < 0.001; control), and −0.15 ± 0.35 and −2.25 ± 0.54 D (P = 0.03; latanoprost). Conclusions In the FD guinea pig model, latanoprost significantly reduces the development of myopia. Although further investigations into underlying mechanisms are needed, the results open the exciting possibility of a new line of myopia control therapy. PMID:29847673

[Stabilizing effectiveness of orthokeratology and long-term minute-concentration atropine therapy in myopia (draft report)].

PubMed

Verzhanskaya, T Yu; Tarutta, E P

The rational for the study was the high prevalence of myopia in the world. According to the World Health Organization (WHO), myopia is one of the five leading causes of blindness and low vision. Of recent reports on conservative measures for the stabilization of myopia, two areas of investigation deserve attention: methods of optical correction that affect peripheral refraction, orthokeratology lenses (OKL) in particular, and pharmacotherapy. The aim of the study was to evaluate the effectiveness and safety of myopia control in pediatric patients by combining two methods - OKL wearing and instillation of extra low doses of atropine (0.01%). Within a prospective cohort study, 31 patients (62 eyes) aged 8 to 14 years with acquired myopia of low 14 (28), medium 11 (22), or high 6 (12) degree, were examined before and 6 months after adding 0.01% atropine instillations to OKL wearing. Refraction (Huvitz MRK 3100P), axial eye length (IOL-Master, 'CarlZeiss', Germany), absolute accommodation (Grand Seiko WRK-5100K), accommodative reserves, and pseudoaccommodation were assessed. The most significant effect on reducing the rate of disease progression was observed in patients with low and moderate myopia (1.5 and 1.7 times, correspondingly, p<0.05). In high myopia no reliable changes were noticed. Obviously, the inhibitory effect of OKL, which is conditioned by optical factors (peripheral myopic defocus in particular), even in combination with atropine, is not able to stop the progression of high myopia, which is based on structural and biomechanical changes of the sclera. Judging from these preliminary results, one should not claim 100% effectiveness of prolonged minute-concentration atropine use, however, the positive effect exists and the study continues.

Cohort study with 4-year follow-up of myopia and refractive parameters in primary schoolchildren in Baoshan District, Shanghai.

PubMed

Ma, Yingyan; Zou, Haidong; Lin, Senlin; Xu, Xun; Zhao, Rong; Lu, Lina; Zhao, Huijuan; Li, Qiangqiang; Wang, Ling; Zhu, Jianfeng; He, Xiangui

2018-03-25

Cohort studies could not only reveal associations between change of refractive components and onset/progression of myopia, but also risk factors, which is important for understanding mechanism and providing strategies. Prevalence of myopia is high in Shanghai, being reported to be 52.2% in children aged 10 years old. Cohort study. A total of 1856 students from six randomly selected primary schools in Baoshan District, Shanghai. Children underwent comprehensive ocular measurement, including axial length (AL), corneal curvature radius and cycloplegic auto-refraction. Questionnaires about eye usage time were collected. Grade 1 students were followed for 4 years, and grade 2 and 3 students for 2 years. (i) Change of spherical equivalent (SE) and AL and (ii) risk factors for progression and incidence of myopia. The average 2-year progress of SE was 0.91D, 0.91D and 1.11D for grade 1, 2 and 3, respectively, and the average elongation of AL was 0.70 mm, 0.64 mm and 0.71 mm, respectively. Only parental myopia, but not near work time, near work diopter time, outdoor activity time or attending tutoring classes, was associated with myopia incidence and progression in the present population. Using baseline SE could be a simple and effective indicator for myopia prediction. Incidence and progression of myopia is relatively high in schoolchildren in Shanghai compared with children of Western countries, East Asia and other parts of China. Effective strategies to control myopia prevalence are in urgent need. © 2018 The Authors Clinical & Experimental Ophthalmology published by John Wiley & Sons Australia, Ltd on behalf of Royal Australian and New Zealand College of Ophthalmologists.

[Effects of orthokeratology lenses on the magnitude of accommodative lag and accommodativeconvergence/accommodation].

PubMed

Ren, Qiujin; Yue, Hui; Zhou, Qing

2016-02-01

To evaluate the change in accommodative lag and accommodation convergence/accommodation (AC/A) after patients with myopia wear orthokeratology lenses. 
 A total of 48 myopic subjects (a test group), who wore orthokeratology lenses regularly, and 48 myopic subjects (a control group), who wore spectacles regularly, were enrolled for this study from January 2011 to January 2013 in Optometric Center, the Forth Hospital of Changsha. Accommodative lag was measured by fused cross cylinder method, where the patients should gaze at the front optotypes 40 cm away. Gradient of the AC/A ratio was measured by Von Grafe method to check closer distance heterophoria. Accommodative lag and AC/A ratio were analyzed by statistics.
 After 1-year follow-up, accommodative lag and AC/A rate in patients with low or moderate myopia in the test group was decreased in 1, 3, 6 months or 1 year compared with that in the control group (P<0.05). 
 Compared with spectacles, orthokeratology lenses are able to decrease accommodative lag and high AC/A rate in patients with low or moderate myopia. The relationship between accommodation and convergence is improved by orthokeratology lenses. Orthokeratology is an effective way to control myopia.

LAMELLAR HOLE-ASSOCIATED EPIRETINAL PROLIFERATION IN LAMELLAR MACULAR HOLE AND FULL-THICKNESS MACULAR HOLE IN HIGH MYOPIA.

PubMed

Lai, Tso-Ting; Yang, Chung-May

2017-05-18

To report findings and surgical outcomes of lamellar macular hole (LMH) or full-thickness macular hole (FTMH) accompanied by lamellar hole-associated epiretinal proliferation (LHEP) in eyes with high myopia (HM). Consecutive cases of HM with LMH or FTMH containing LHEP were retrospectively reviewed (study group, 43 cases). Cases of HM without LHEP (22) and those of non-HM with LHEP (30) served as Control A and B. The study group showed larger (928.7 ± 381.9 μm) and deeper (remained base thickness: 79.7 ± 23.7 μm) LMH retinal defect than that in Control A (466.2 ± 179.1 and 99.9 ± 24.9) and B (647.1 ± 346.7 and 99.1 ± 38.1). Lamellar hole-associated epiretinal proliferation in the study group had a higher rate of wide extension (42.3%) and growing along the posterior hyaloid (PH, 53.8%). Patients with LMH who underwent surgery in the study group and Control A showed limited best corrected visual acuity (BCVA) improvement (0-1 and 1-2 ETDRS lines, respectively), while Control B had significant improvement (4-5 lines). For full-thickness macular holes, the study group was the youngest (50.0 ± 11.4) and LHEP was more likely to grow on the posterior hyaloid (23.5%); the postoperative best corrected visual acuity, however, was similar to that in Control A (20/63-20/80). Lamellar hole-associated epiretinal proliferation in HM tended to be more widespread and adherent to the posterior hyaloid than in eyes without HM. Visual outcomes after LMH repair in eyes with LHEP and HM are less favorable than eyes with LHEP and without HM, but similar to eyes with HM and without LHEP.

Caucasian Families Exhibit Significant Linkage of Myopia to Chromosome 11p.

PubMed

Musolf, Anthony M; Simpson, Claire L; Moiz, Bilal A; Long, Kyle A; Portas, Laura; Murgia, Federico; Ciner, Elise B; Stambolian, Dwight; Bailey-Wilson, Joan E

2017-07-01

Myopia is a common visual disorder caused by eye overgrowth, resulting in blurry vision. It affects one in four Americans, and its prevalence is increasing. The genetic mechanisms that underpin myopia are not completely understood. Here, we use genotype data and linkage analyses to identify high-risk genetic loci that are significantly linked to myopia. Individuals from 56 Caucasian families with a history of myopia were genotyped on an exome-based array, and the single nucleotide polymorphism (SNP) data were merged with microsatellite genotype data. Refractive error measures on the samples were converted into binary phenotypes consisting of affected, unaffected, or unknown myopia status. Parametric linkage analyses assuming an autosomal dominant model with 90% penetrance and 10% phenocopy rate were performed. Single variant two-point analyses yielded three significantly linked SNPs at 11p14.1 and 11p11.2; a further 45 SNPs at 11p were found to be suggestive. No other chromosome had any significant SNPs or more than seven suggestive linkages. Two of the significant SNPs were located in BBOX1-AS1 and one in the intergenic region between ORA47 and TRIM49B. Collapsed haplotype pattern two-point analysis and multipoint analyses also yielded multiple suggestively linked genes at 11p. Multipoint analysis also identified suggestive evidence of linkage on 20q13. We identified three genome-wide significant linked variants on 11p for myopia in Caucasians. Although the novel specific signals still need to be replicated, 11p is a promising region that has been identified by other linkage studies with a number of potentially interesting candidate genes. We hope that the identification of these regions on 11p as potential causal regions for myopia will lead to more focus on these regions and maybe possible replication of our specific linkage peaks in other studies. We further plan targeted sequencing on 11p for our most highly linked families to more clearly understand the source of the linkage in this region.

Biometric Risk Factors for Corneal Neovascularization Associated with Hydrogel Soft Contact Lens Wear in Korean Myopic Patients

PubMed Central

Lee, Dae Seung; Wee, Won Ryang

2014-01-01

Purpose To investigate the biometric risk factors for corneal surface complications associated with hydrogel soft contact lens (SCL) fitting in myopic patients in Korea. Methods This is a retrospective case-control study. The records of 124 subjects (124 eyes) who wore SCLs on a daily basis were reviewed. Thirty-one patients (31 eyes) who were diagnosed with corneal neovascularization (NV) while wearing SCLs were included in the complication group. Ninety-three age- and sex-matched patients (93 eyes) who wore SCLs, who did not have corneal NV and who visited our clinic for correction of refractive errors were included in the control group. The degree of spherical equivalent, astigmatism and corneal base curve radius (BCR) were compared in both groups. Results Patients with NV exhibited poorer best corrected visual acuity and more myopia than controls (p = 0.008 and 0.006, respectively). In univariate analysis, highly myopic patients (-9 diopters [D] or higher) were more likely to experience NV (odds ratio [OR], 2.232; 95% confidence interval [CI], 1.602 to 3.105). High astigmatism (≥2 D) increased the risk of complications (OR, 2.717; 95% CI, 1.141 to 6.451). Steep cornea, in which BCR was <7.5 mm, also raised the risk of complications (OR, 4.000; 95% CI, 1.661 to 9.804). Flat cornea was not a risk factor for the development of NV. Conclusions High myopia, high astigmatism, and steep cornea seemed to be risk factors in the development of corneal NV in SCL wearers. PMID:25120337

Biometric risk factors for corneal neovascularization associated with hydrogel soft contact lens wear in Korean myopic patients.

PubMed

Lee, Dae Seung; Kim, Mee Kum; Wee, Won Ryang

2014-08-01

To investigate the biometric risk factors for corneal surface complications associated with hydrogel soft contact lens (SCL) fitting in myopic patients in Korea. This is a retrospective case-control study. The records of 124 subjects (124 eyes) who wore SCLs on a daily basis were reviewed. Thirty-one patients (31 eyes) who were diagnosed with corneal neovascularization (NV) while wearing SCLs were included in the complication group. Ninety-three age- and sex-matched patients (93 eyes) who wore SCLs, who did not have corneal NV and who visited our clinic for correction of refractive errors were included in the control group. The degree of spherical equivalent, astigmatism and corneal base curve radius (BCR) were compared in both groups. Patients with NV exhibited poorer best corrected visual acuity and more myopia than controls (p = 0.008 and 0.006, respectively). In univariate analysis, highly myopic patients (-9 diopters [D] or higher) were more likely to experience NV (odds ratio [OR], 2.232; 95% confidence interval [CI], 1.602 to 3.105). High astigmatism (≥2 D) increased the risk of complications (OR, 2.717; 95% CI, 1.141 to 6.451). Steep cornea, in which BCR was <7.5 mm, also raised the risk of complications (OR, 4.000; 95% CI, 1.661 to 9.804). Flat cornea was not a risk factor for the development of NV. High myopia, high astigmatism, and steep cornea seemed to be risk factors in the development of corneal NV in SCL wearers.

Prevalence and Associated Factors of Myopia in High-School Students in Beijing

PubMed Central

Duan, Jia Li; Luo, Yan Xia; Liu, Li Juan; Li, Xia; Gao, Qi; Zhu, Hui Ping; He, Yan; Xu, Liang; Jonas, Jost B; Wang, Wei; Guo, Xiu Hua

2015-01-01

Purpose To evaluate prevalence and associated factors for myopia in high school students in Beijing. Methods Grade 10 and 11 high school students were randomly selected from nine randomly selected districts of Beijing. The students underwent non-cylcoplegic auto-refractometry and an interview. Results Out of 4798 eligible students, 4677 (93.4%) students (mean age:16.9±0.7years;range:16–18 years) participated. Mean refractive error of right eyes and left eyes was −2.78±2.29 diopters and −2.59±2.50 diopters, respectively. Prevalence of myopia (defined as ≤ −1.00 diopters in the worse eye) was 80.7% (95% Confidence Interval (CI): 79.6–81.8%). Out of 3773 students with myopia, 1525 (40.4%) wore glasses daily. In multiple logistic regression analysis, a higher prevalence of myopia was associated with female sex (odds ratio (OR) = 1.31;95%CI:1.11–1.55), Han ethnicity (OR = 1.64;95%CI:1.28–2.11), attending key schools (OR = 1.48;95%CI:1.24,1.77), higher family income (OR = 1.37;95%CI:1.09–1.71), longer time spent for near work (OR = 1.43;95%CI:1.06–1.93), shorter near work distance (OR = 1.87;95%CI:1.55–2.26), lower frequency of active rest during studying (OR = 1.40;95%CI:1.16–1.70), and parental myopia (OR = 2.28;95%CI:1.80–2.87). The interaction between distance from near work and time spent for near work was statistically (P = 0.03) significant. In multiple logistic regression analysis, higher prevalence of high myopia (≤-6.0 diopters) was associated with studying in key schools (OR = 1.38;95%CI:1.05,1.81), lower frequency of active rest during studying (OR = 1.40;95%CI:1.09,1.79), and a higher number of myopic parents (OR = 2.66;95%CI:2.08,3.40). Conclusions A prevalence of about 80% for myopia and a prevalence of about 10% for high myopia in students aged 16 to 18 years and attending classes of grade 10 and 11 in a Chinese metropolitan region is another example of the high prevalence of moderate and high myopia in metropolitan areas of China. With this young myopic generation getting older, myopia as cause for visual impairment and blindness may further increase in importance. Future studies may address whether active rests during studying with looking into the distance are preventive against myopia development or progression. PMID:25803875

Genome-wide meta-analyses of multiancestry cohorts identify multiple new susceptibility loci for refractive error and myopia.

PubMed

Verhoeven, Virginie J M; Hysi, Pirro G; Wojciechowski, Robert; Fan, Qiao; Guggenheim, Jeremy A; Höhn, René; MacGregor, Stuart; Hewitt, Alex W; Nag, Abhishek; Cheng, Ching-Yu; Yonova-Doing, Ekaterina; Zhou, Xin; Ikram, M Kamran; Buitendijk, Gabriëlle H S; McMahon, George; Kemp, John P; Pourcain, Beate St; Simpson, Claire L; Mäkelä, Kari-Matti; Lehtimäki, Terho; Kähönen, Mika; Paterson, Andrew D; Hosseini, S Mohsen; Wong, Hoi Suen; Xu, Liang; Jonas, Jost B; Pärssinen, Olavi; Wedenoja, Juho; Yip, Shea Ping; Ho, Daniel W H; Pang, Chi Pui; Chen, Li Jia; Burdon, Kathryn P; Craig, Jamie E; Klein, Barbara E K; Klein, Ronald; Haller, Toomas; Metspalu, Andres; Khor, Chiea-Chuen; Tai, E-Shyong; Aung, Tin; Vithana, Eranga; Tay, Wan-Ting; Barathi, Veluchamy A; Chen, Peng; Li, Ruoying; Liao, Jiemin; Zheng, Yingfeng; Ong, Rick T; Döring, Angela; Evans, David M; Timpson, Nicholas J; Verkerk, Annemieke J M H; Meitinger, Thomas; Raitakari, Olli; Hawthorne, Felicia; Spector, Tim D; Karssen, Lennart C; Pirastu, Mario; Murgia, Federico; Ang, Wei; Mishra, Aniket; Montgomery, Grant W; Pennell, Craig E; Cumberland, Phillippa M; Cotlarciuc, Ioana; Mitchell, Paul; Wang, Jie Jin; Schache, Maria; Janmahasatian, Sarayut; Janmahasathian, Sarayut; Igo, Robert P; Lass, Jonathan H; Chew, Emily; Iyengar, Sudha K; Gorgels, Theo G M F; Rudan, Igor; Hayward, Caroline; Wright, Alan F; Polasek, Ozren; Vatavuk, Zoran; Wilson, James F; Fleck, Brian; Zeller, Tanja; Mirshahi, Alireza; Müller, Christian; Uitterlinden, André G; Rivadeneira, Fernando; Vingerling, Johannes R; Hofman, Albert; Oostra, Ben A; Amin, Najaf; Bergen, Arthur A B; Teo, Yik-Ying; Rahi, Jugnoo S; Vitart, Veronique; Williams, Cathy; Baird, Paul N; Wong, Tien-Yin; Oexle, Konrad; Pfeiffer, Norbert; Mackey, David A; Young, Terri L; van Duijn, Cornelia M; Saw, Seang-Mei; Bailey-Wilson, Joan E; Stambolian, Dwight; Klaver, Caroline C; Hammond, Christopher J

2013-03-01

Refractive error is the most common eye disorder worldwide and is a prominent cause of blindness. Myopia affects over 30% of Western populations and up to 80% of Asians. The CREAM consortium conducted genome-wide meta-analyses, including 37,382 individuals from 27 studies of European ancestry and 8,376 from 5 Asian cohorts. We identified 16 new loci for refractive error in individuals of European ancestry, of which 8 were shared with Asians. Combined analysis identified 8 additional associated loci. The new loci include candidate genes with functions in neurotransmission (GRIA4), ion transport (KCNQ5), retinoic acid metabolism (RDH5), extracellular matrix remodeling (LAMA2 and BMP2) and eye development (SIX6 and PRSS56). We also confirmed previously reported associations with GJD2 and RASGRF1. Risk score analysis using associated SNPs showed a tenfold increased risk of myopia for individuals carrying the highest genetic load. Our results, based on a large meta-analysis across independent multiancestry studies, considerably advance understanding of the mechanisms involved in refractive error and myopia.

Comparative analysis of the efficacy of astigmatic correction after wavefront-guided and wavefront-optimized LASIK in low and moderate myopic eyes

PubMed Central

Khalifa, Mounir A.; Alsahn, Mahmoud F.; Shaheen, Mohamed Shafik; Pinero, David P.

2017-01-01

AIM To evaluate and compare the efficacy of the astigmatic correction achieved with laser in situ keratomileusis (LASIK) in eyes with myopic astigmatism using wavefront-guided (WFG) and wavefront-optimized (WFO) ablation profiles. METHODS Prospective study included 221 eyes undergoing LASIK: 99 and 122 eyes with low and moderate myopic astigmatism (low and moderate myopia groups). Two subgroups were differentiated in each group according to the ablation profile: WFG subgroup, 109 eyes (45/64, low/moderate myopia groups) treated using the Advanced CustomVue platform (Abbott Medical Optics Inc.), and WFO subgroup, 112 eyes (54/58, low/moderate myopia groups) treated using the EX-500 platform (Alcon). Clinical outcomes were evaluated during a 6-month follow-up, including a vector analysis of astigmatic changes. RESULTS Significantly better postoperative uncorrected visual acuity and efficacy index was found in the WFG subgroups of each group (P≤0.041). Postoperative spherical equivalent and cylinder were significantly higher in WFO subgroups (P≤0.003). In moderate myopia group, a higher percentage of eyes with a postoperative cylinder ≤0.25 D was found in the WFG subgroup (90.6% vs 65.5%, P=0.002). In low and moderate myopia groups, the difference vector was significantly higher in the WFO subgroup compared to WFG (P<0.001). In moderate myopia group, the magnitude (P=0.008) and angle of error (P<0.001) were also significantly higher in the WFO subgroup. Significantly less induction of high order aberrations were found with WFG treatments in both low and moderate myopia groups (P≤0.006). CONCLUSION A more efficacious correction of myopic astigmatism providing a better visual outcome is achieved with WFG LASIK compared to WFO LASIK. PMID:28251090

Nearwork in early-onset myopia.

PubMed

Saw, Seang-Mei; Chua, Wei-Han; Hong, Ching-Ye; Wu, Hui-Min; Chan, Wai-Ying; Chia, Kee-Seng; Stone, Richard A; Tan, Donald

2002-02-01

To determine the relationship of nearwork and myopia in young elementary school-age children in Singapore. A cross-sectional study of 1005 school children aged 7 to 9 years was conducted in two schools in Singapore. Cycloplegic autorefraction, keratometry, and biometry measurements were performed. In addition, the parents completed a detailed questionnaire on nearwork activity (books read per week, reading in hours per day and diopter hours [addition of three times reading, two times computer use, and two times video games use in hours per day]). Other risk factors, such as parental myopia, socioeconomic status, and light exposure history, were assessed. In addition to socioeconomic factors, several nearwork indices were associated with myopia in these young children. The multivariate adjusted odds ratio of higher myopia (at least -3.0 D) for children who read more than two books per week was 3.05 (95% confidence interval [CI], 1.80-5.18). However, the odds ratios of higher myopia for children who read more than 2 hours per day or with more than 8 diopter hours (1.50; 95% CI, 0.87-2.55 and 1.04; 95% CI, 0.61-1.78, respectively) were not significant, after controlling for several factors. Children aged 7 to 9 years with a greater current reading exposure were more likely to be myopic. This association of reading and myopia in a young age cohort was greater than the strength of the reading association generally found in older myopic subjects. Whether these results identify an association of early-onset myopia with nearwork activity or other potentially confounding factors is discussed.

"They Can't Even Play Right!" Cultural Myopia in the Analysis of Play--Cultural Perspectives on Human Development.

ERIC Educational Resources Information Center

Meier, Terry; Murrell, Peter C., Jr.

Using the framework of cultural context analysis, this paper examines how cultural myopia can lead to inaccurate generalizations regarding play and development among children in diverse sociocultural groups in the United States. The paper argues that analyses drawing causal connections between playing with particular toys or in certain ways and…

Effect of Orthokeratology on myopia progression: twelve-year results of a retrospective cohort study.

PubMed

Lee, Yueh-Chang; Wang, Jen-Hung; Chiu, Cheng-Jen

2017-12-08

Several studies reported the efficacy of orthokeratology for myopia control. Somehow, there is limited publication with follow-up longer than 3 years. This study aims to research whether overnight orthokeratology influences the progression rate of the manifest refractive error of myopic children in a longer follow-up period (up to 12 years). And if changes in progression rate are found, to investigate the relationship between refractive changes and different baseline factors, including refraction error, wearing age and lens replacement frequency. In addition, this study collects long-term safety profile of overnight orthokeratology. This is a retrospective study of sixty-six school-age children who received overnight orthokeratology correction between January 1998 and December 2013. Thirty-six subjects whose baseline age and refractive error matched with those in the orthokeratology group were selected to form control group. These subjects were followed up at least for 12 months. Manifest refractions, cycloplegic refractions, uncorrected and best-corrected visual acuities, power vector of astigmatism, corneal curvature, and lens replacement frequency were obtained for analysis. Data of 203 eyes were derived from 66 orthokeratology subjects (31 males and 35 females) and 36 control subjects (22 males and 14 females) enrolled in this study. Their wearing ages ranged from 7 years to 16 years (mean ± SE, 11.72 ± 0.18 years). The follow-up time ranged from 1 year to 13 years (mean ± SE, 6.32 ± 0.15 years). At baseline, their myopia ranged from -0.5 D to -8.0 D (mean ± SE, -3.70 ± 0.12 D), and astigmatism ranged from 0 D to -3.0 D (mean ± SE, -0.55 ± 0.05 D). Comparing with control group, orthokeratology group had a significantly (p < 0.001) lower trend of refractive error change during the follow-up periods. According to the analysis results of GEE model, greater power of astigmatism was found to be associated with increased change of refractive error during follow-up years. Overnight orthokeratology was effective in slowing myopia progression over a twelve-year follow-up period and demonstrated a clinically acceptable safety profile. Initial higher astigmatism power was found to be associated with increased change of refractive error during follow-up years.

An angle-supported foldable phakic intraocular lens for correction of myopia: A five-year follow-up.

PubMed

Alió, J L; Plaza-Puche, A B; Cavas, F; Yébana Rubio, P; Sala, E

2017-01-01

To evaluate the efficacy and safety of an angle-supported foldable phakic intraocular lens (pIOL) for the correction of moderate to high myopia after 5 years follow-up. Prospective and retrospective, observational, longitudinal, non-randomised consecutive series of cases conducted on a total of 100 eyes of 67 patients with moderate to high myopia implanted with an Acrysof Cachet pIOL (Alcon Laboratories Inc.) with the aim of minimising the refractive error. The ages ranged between 18 to 60years. Uncorrected distance visual acuity (UDVA), manifest refraction, corrected distance visual acuity (CDVA), endothelial cells density, pIOL position, intraocular pressure, and complications were recorded preoperatively and during the 5 year follow-up. Five years after implantation, the mean manifest spherical equivalent refraction reduced significantly from -11.62±3.35 dioptres (D) to -0.33±0.85D. UDVA was 20/20 or better in 5 of 25 cases (20%), and 20/40 or better in 22 cases (88%). CDVA was 20/20 or better in 17 cases (68%), and 20/32 or better in 23 cases (92%) of eyes. The residual refractive error was within ±0.50D of emmetropia in 12 cases (48%), and within ±1.00D in 19 cases (76%). Mean endothelial cell loss at 5 years was 11.8% central, and 13.7% peripheral. Mean endothelium-pIOL distance was 2.11±0.18mm, and mean pIOL-crystalline distance was 0.88±0.20mm. This angle supported pIOL provided a favourable refractive correction and predictability, as well as acceptable safety in patients with moderate to high myopia. Although endothelial cell density decreased over 5years, the results are within the range reported in previous studies with other pIOLs. Copyright © 2016 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

Discontinuation of orthokeratology on eyeball elongation (DOEE).

PubMed

Cho, P; Cheung, S W

2017-04-01

To evaluate and compare changes in axial elongation, over a 14-month period, in subjects who discontinued and then resumed ortho-k lens wear with those who continued to wear their lenses or spectacles following a 2-year myopia control study. This single masked, prospective study recruited subjects who had just completed a 2-year myopia control study. Ortho-k subjects were classified as Group OKc, in which subjects continued ortho-k lens wear for the duration of the study; or Group OKd in which subjects discontinued lens wear for seven months and wore single-vision spectacles (Phase I) and then resumed ortho-k lens wear for another seven months (Phase II). Spectacle-wearing control subjects from the initial myopia control study continued wearing spectacles as control subjects. Axial lengths were measured at scheduled visits using the IOLMaster. Thirteen, 16, and 15 Control, OKc, and OKd subjects, aged 8-14 years, respectively completed the study. Significant increase in axial elongation was found in OKd subjects only in Phase I but not in Phase II. On resuming lens wear, in Phase II, the rate of axial elongation was no longer significantly different from those of the Control or OKc subjects. Stopping ortho-k lens wear at or before the age of 14 years led to a more rapid increase in axial length; comparable to those wearing spectacles during the initial 2-year myopia control study, but greater than the Control and OKc group in this study. Axial elongation slowed again with resumed lens wear after six months. Copyright © 2016 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Influence of periodic vs continuous daily bright light exposure on development of experimental myopia in the chick.

PubMed

Backhouse, Simon; Collins, Andrew V; Phillips, John R

2013-09-01

In children, time spent outdoors has a protective effect against myopia development. In animal models, bright light reduces the development of experimental myopia. This study investigates how an increase in daily light exposure, presented either continuously during the day or periodically at different times of day, influences the development of experimental myopia in the chick. Myopia was induced in Cobb Chicks (Gallus domesticus) by monocular deprivation (MD) of form vision with a translucent diffuser for 3 days (from 4 days of age) under a 12:12 light: dark cycle. MD control chicks were exposed to constant 300 lux (n = 11) during the light period. MD treatment groups received either constant 2000 lux (n = 11) during the light period or 300 lux for 10 h with a 2 h period of bright light (10 000 lux), either in the morning (n = 10), midday (n = 10) or evening (n = 10), giving the same total daily light exposure as the 2000 lux group. After 3 days of MD, refractive status, corneal curvature and axial eye dimensions were measured for all eyes under anaesthesia. Myopia in the constant 2000 lux group (-4.94 ± 1.21 D) was significantly less than in the 300 lux control group (-9.73 ± 0.96 D; p = 0.022). However, compared to the 300 lux control group, 2 h periods of 10 000 lux did not produce significant effects on refraction when presented either in the morning (-9.98 ± 0.85; p = 1.00), midday (-8.00 ± 1.26; p = 0.80), or evening (-13.14 ± 1.16 D; p = 0.20), although significantly less myopia was induced in the midday group compared to the evening group (p = 0.018). Orthogonal regression showed that myopia development was matched by changes in vitreous chamber depth (R(2)  = 0.69; p < 0.0001). In chicks, an increase in daily light exposure continuously during the day is more effective at inhibiting myopia than adding an equivalent dose within a 2 h period of bright light. A weak time-of-day effect also appears to be present in the response to bright light exposure. Our results suggest that future light-based myopia therapies in humans may be more effective if light levels are increased over the whole day, rather than through short periods of bright light exposure. © 2013 The Authors Ophthalmic & Physiological Optics © 2013 The College of Optometrists.

Assessing the Genetic Predisposition of Education on Myopia: a Mendelian Randomization Study

PubMed Central

Cuellar-Partida, Gabriel; Lu, Yi; Kho, Pik Fang; Hewitt, Alex W.; Wichmann, H.-Erich; Yazar, Seyhan; Stambolian, Dwight; Bailey-Wilson, Joan E.; Wojciechowski, Robert; Wang, Jie Jin; Mitchell, Paul; Mackey, David A.; MacGregor, Stuart

2016-01-01

Myopia is the largest cause of uncorrected visual impairments globally and its recent dramatic increase in the population has made it a major public health problem. In observational studies, educational attainment has been consistently reported to be correlated to myopia. Nonetheless, correlation does not imply causation. Observational studies do not tell us if education causes myopia or if instead there are confounding factors underlying the association. In this work, we use a two-step least squares instrumental-variable (IV) approach to estimate the causal effect of education on refractive error, specifically myopia. We used the results from the educational attainment GWAS from the Social Science Genetic Association Consortium to define a polygenic risk score (PGRS) in three cohorts of late middle age and elderly Caucasian individuals (N=5,649). In a meta-analysis of the three cohorts, using the PGRS as an IV, we estimated that each z-score increase in education (approximately 2 years of education) results in a reduction of 0.92 ± 0.29 diopters (P=1.04×10−3). Our estimate of the effect of education on myopia was higher (P=0.01) than the observed estimate (0.25 ± 0.03 diopters reduction per education z-score [~2 years] increase). This suggests that observational studies may actually underestimate the true effect. Our Mendelian Randomization (MR) analysis provides new evidence for a causal role of educational attainment on refractive error. PMID:26497973

Assessing the Genetic Predisposition of Education on Myopia: A Mendelian Randomization Study.

PubMed

Cuellar-Partida, Gabriel; Lu, Yi; Kho, Pik Fang; Hewitt, Alex W; Wichmann, H-Erich; Yazar, Seyhan; Stambolian, Dwight; Bailey-Wilson, Joan E; Wojciechowski, Robert; Wang, Jie Jin; Mitchell, Paul; Mackey, David A; MacGregor, Stuart

2016-01-01

Myopia is the largest cause of uncorrected visual impairments globally and its recent dramatic increase in the population has made it a major public health problem. In observational studies, educational attainment has been consistently reported to be correlated to myopia. Nonetheless, correlation does not imply causation. Observational studies do not tell us if education causes myopia or if instead there are confounding factors underlying the association. In this work, we use a two-step least squares instrumental-variable (IV) approach to estimate the causal effect of education on refractive error, specifically myopia. We used the results from the educational attainment GWAS from the Social Science Genetic Association Consortium to define a polygenic risk score (PGRS) in three cohorts of late middle age and elderly Caucasian individuals (N = 5,649). In a meta-analysis of the three cohorts, using the PGRS as an IV, we estimated that each z-score increase in education (approximately 2 years of education) results in a reduction of 0.92 ± 0.29 diopters (P = 1.04 × 10(-3) ). Our estimate of the effect of education on myopia was higher (P = 0.01) than the observed estimate (0.25 ± 0.03 diopters reduction per education z-score [∼2 years] increase). This suggests that observational studies may actually underestimate the true effect. Our Mendelian Randomization (MR) analysis provides new evidence for a causal role of educational attainment on refractive error. © 2015 WILEY PERIODICALS, INC.

Corneal shape and astigmatism: with a note on myopia.

PubMed Central

Weale, R A

1988-01-01

The elliptical shape and the physiological astigmatism of the normal neonatal human cornea are attributed to the ellipsoidal shape of the eyeball. This in turn is a feature of ocular development. The analysis is used to examine earlier observations on myopia. PMID:3179259

Epipolis-laser in situ keratomileusis versus photorefractive keratectomy for the correction of myopia: a meta-analysis.

PubMed

Wu, Wenjing; Wang, Yan; Xu, Lulu

2015-10-01

It is unclear whether epipolis-laser in situ keratomileusis (Epi-LASIK) has any significant advantage over photorefractive keratectomy (PRK) for correcting myopia. We undertook this meta-analysis of randomized controlled trials and cohort studies to examine possible differences in efficacy, predictability, and side effects between Epi-LASIK and PRK for correcting myopia. A system literature review was conducted in the PubMed, Cochrane Library EMBASE. The statistical analysis was performed by RevMan 5.0 software. The results included efficacy outcomes (percentage of eyes with 20/20 uncorrected visual acuity post-treatment), predictability (proportion of eyes within ±0.5 D of the target refraction), epithelial healing time, and the incidence of significant haze and pain scores after surgery. There are seven articles with total 987 eyes suitable for the meta-analysis. There is no statistical significance in the predictability between Epi-LASIK and PRK, the risk ratio (RR) is 1.03, 95% confidence interval (CI) [0.92, 1.16], p = 0.18; with respect to efficacy, the odds ratio is 1.43, 95% CI = [0.85, 2.40], p = 0.56 between Epi-LASIK and PRK, there is no statistical significance either. The epithelial cell layer healing time and the pain scores and the incidence of significant haze showed no significance between these two techniques although more pains can be found in Epi-LASIK than PRK at the early-stage post-operation. According to the above analysis, Epi-LASIK has good efficacy and predictability as PRK. In addition, both techniques have low pain scores and low incidence of significant haze.

Defocus Incorporated Soft Contact (DISC) lens slows myopia progression in Hong Kong Chinese schoolchildren: a 2-year randomised clinical trial

PubMed Central

Lam, Carly Siu Yin; Tang, Wing Chun; Tse, Dennis Yan-Yin; Tang, Ying Yung; To, Chi Ho

2014-01-01

Aims To determine if ‘Defocus Incorporated Soft Contact’ (DISC) lens wear slows childhood myopia progression. Methods A 2-year double-blind randomised controlled trial was carried out in 221 children aged 8–13 years, with myopia between −1.00 and −5.00 Dioptres (D) and astigmatism ≤1.00 D. Subjects were randomly assigned to the DISC (n=111) or single vision (SV; n=110) contact lens group. DISC lenses incorporated concentric rings, which provided an addition of +2.50 D, alternating with the normal distance correction. Refractive error (cycloplegic autorefraction) and axial length were measured at 6-month intervals. Differences between groups were analysed using unpaired t test. Results In total, 128 children completed the study, n=65 in the DISC group and n=63 in the SV group. Myopia progressed 25% more slowly for children in the DISC group compared with those in the control group (0.30 D/year; 95% CI −0.71 to −0.47 vs 0.4 D/year; 95% CI −0.93 to −0.65, p=0.031). Likewise, there was less axial elongation for children in the DISC versus SV groups (0.13 mm/year; 95% CI 0.20 to 0.31 vs 0.18 mm/year; 95% CI 0.30 to 0.43, p=0.009). Treatment effect correlated positively with DISC lens wearing time (r=0.342; p=0.005). Indeed, myopia in children who wore the DISC lenses for five or more hours/day progressed 46% (mean difference=−0.382 D, p=0.001; 95% CI −0.59 to −0.17) less than those in the SV group. Conclusions The daily wearing of DISC lens significantly slowed myopia progression and axial elongation in Hong Kong schoolchildren. The findings demonstrated that simultaneous clear vision with constant myopic defocus can retard myopia progression. PMID:24169657

[The relationship between eyeball structure and visual acuity in high myopia].

PubMed

Liu, Yi-Chang; Xia, Wen-Tao; Zhu, Guang-You; Zhou, Xing-Tao; Fan, Li-Hua; Liu, Rui-Jue; Chen, Jie-Min

2010-06-01

To explore the relationship between eyeball structure and visual acuity in high myopia. Totally, 152 people (283 eyeballs) with different levels of myopia were tested for visual acuity, axial length, and fundus. All cases were classified according to diopter, axial length, and fundus. The relationships between diopter, axial length, fundus and visual acuity were studied. The mathematical models were established for visual acuity and eyeball structure markers. The visual acuity showed a moderate correlation with fundus class, comus, axial length and diopter ([r] > 0.4, P < 0.000 1). The visual acuity in people with the axial length longer than 30.00 mm, diopter above -20.00 D and fundus in 4th class were mostly below 0.5. The mathematical models were established by visual acuity and eyeball structure markers. The visual acuity should decline with axial length extension, diopter deepening and pathological deterioration of fundus. To detect the structure changes by combining different kinds of objective methods can help to assess and to judge the vision in high myopia.

Visual outcome and refractive status in first 3 years of age in preterm infants suffered from laser-treated Type 1 retinopathy of prematurity (ROP): a 6-year retrospective review in a tertiary centre in Hong Kong.

PubMed

Lok, Julie Y C; Yip, Wilson W K; Luk, Abbie S W; Chin, Joyce K Y; Lau, Henry H W; Young, Alvin L

2018-02-01

To report the visual outcome and refractive status in first 3 years of age in preterm infants suffered from laser-treated Type 1 retinopathy of prematurity (ROP): a 6-year review in Hong Kong DESIGN: Retrospective case series METHODOLOGY: Clinical records of all infants suffered from Type 1 ROP who had undergone laser therapy between 2007 and 2012 were retrospectively reviewed. Basic demographic data, serial changes of refractive error, visual acuity, severity of ROP and laser were analyzed. Correlation with myopia and astigmatism progression, body weight, height, growth and gestational age were also analyzed. Among 494 babies screened, 14 Chinese babies (26 eyes) recruited with 1:1 male-to-female ratio in this study. All eyes showed gradual progression of myopia in first 3 years of age but no significant change of astigmatism. Further correlation analysis showed no correlation with laser energy consumed, birth weight (p = 0.14), head circumference growth (p = 0.57) and body weight growth (p = 0.71). However, severity of myopia was related to the post-conceptual age when receiving laser therapy (p < 0.005), gestation age (p = 0.02) and possibly body height growth with age (p = 0.05). Myopia in early life is one of the most common ocular sequelae in Type 1 ROP survivors. Early detection of refractive error is important for prompt correction and visual rehabilitation to prevent amblyopia.

Relation Between Near Work and Myopia Progression in Student Population

PubMed Central

Muhamedagic, Lejla; Muhamedagic, Belma; Halilovic, Emina Alimanovic; Halimic, Jasmina Alajbegovic; Stankovic, Aleksa; Muracevic, Bedrana

2014-01-01

Aim To determine relation between near work and myopia progression in student population. Causes of myopia occurrence are not sufficiently explained. Methods This retrospective-prospective, descriptive research included 100 students with verified myopia up to -3 Dsph. Ophthalmological examination and measurement diopter-hours variable (Dh) were done twice, in the period from January 2011 until January 2012. Results A multivariate regression analysis of impact on the difference of distance visual acuity without correction to the right and left eye and difference of automatic computer refractometry in cycloplegia of both eyes indicates that, diopter-hours variable (Dh) had statistically significant impact on increase of distance visual acuity difference (right eye OR: I measurement–Dh 1.489, II measurement–Dh 1.544, p<0.05; left eye OR: I measurement–Dh 1.602, II measurement–Dh 1.538, p<0.05) and automatic computer refractometry in cycloplegia (right eye OR: I measurement 1.361, II measurement 1.493, p<0.05; left eye OR: I measurement 0.931, II measurement 1.019, p<0.05) during both measurements. Conclusion Near work cause the increase of myopia. This research opened a perspective for other researches on the impact of near work on myopia. PMID:24944532

Lenticular accommodation in relation to ametropia: the chick model.

PubMed

Choh, Vivian; Sivak, Jacob G

2005-03-04

Our goal was to determine whether experimentally induced ametropias have an effect on lenticular accommodation and spherical aberration. Form-deprivation myopia and hyperopia were induced in one eye of hatchling chicks by application of a translucent goggle and +15 D lens, respectively. After 7 days, eyes were enucleated and lenses were optically scanned prior to accommodation, during accommodation, and after accommodation. Accommodation was induced by electrical stimulation of the ciliary nerve. Lenticular focal lengths for form-deprived eyes were significantly shorter than for their controls and accommodation-associated changes in focal length were significantly smaller in myopic eyes compared to their controls. For eyes imposed with +15 D blur, focal lengths were longer than those for their controls and accommodative changes were greater. Spherical aberration of the lens increased with accommodation in both form-deprived and lens-treated birds, but induction of ametropia had no effect on lenticular spherical aberration in general. Nonmonotonicity from lenticular spherical aberration increased during accommodation but effects of refractive error were equivocal. The crystalline lens contributes to refractive error changes of the eye both in the case of myopia and hyperopia. These changes are likely attributable to global changes in the size and shape of the eye.

[Impacts of rotating or lifting-thrusting manipulation on distant vision of naked eye in patients of juvenile myopia: a randomized controlled trial].

PubMed

Tao, Xiao-Yan; Zhao, Bai-Yiao; Han, Xiao; Dong, Xiao-Yu; Yan, An; Ren, Xu-Ru; Liu, Yan-Wen; Qu, Chang; Xia, Shu-Fen; Yang, Jia-Le

2014-05-01

To compare the differences in the efficacy on distant version of naked eye in the patients of juvenile myopia between rotating manipulation and lifting-thrusting manipulation of acupuncture. One hundred and twenty cases (240 eyes) were randomized into a rotating manipulation group and a lifting-thrusting manipulation group, 60 cases (120 eyes) in each group. Additionally, a corrective lenses group, 60 cases (120 eyes), was set up as the control. In both manipulation groups, Cuanzhu (BL 2),Yuyao (EX-HN 4), Sizhukong (TE 23), Taiyang (EX-HN 5), Fengchi (GB 20), Zusanli (ST 36), Guangming (GB 37) and Sanyinjiao (SP 6) were punctured, but stimulated with rotating manipulation and lifting-thrusting manipulation respectively three times per week, 10 times as a treatment session and totally one session was required. In the corrective lenses group, the glasses were applied at daytime. The clinical efficacy and the changes in distant vision of naked eye before and after treatment were compared among the three groups. The total effective rate was 87.5% (105/120) in the rotating manipulation group, which was better than 69.2% (83/120) in the lifting-thrusting manipulation group (P < 0.05). The distant vision of naked eye was improved apparently in the rotating manipulation group and the lifting-thrusting manipulation group after treatment (both P < 0.05). But it was not improved in the corrective lenses group (P > 0.05). The distant vision of naked eye was improved more apparently after treatment in the rotating manipulation group as compared with that in the lifting-thrusting manipulation group (0.75 +/- 0.23 vs 0.68 +/- 0.24, P < 0.05). For 96 cases (192 eyes) with acupuncture treatment, in 3-month follow-up, 87.0% (167/192) of the cases maintained the stable vision as the original level and 13.0% (25/192) of them were reduced in the vision In the acupuncture groups, it was found that the improvement of distant vision of naked eye was more obvious after treatment with younger age, better basic vision and shorter duration of sickness (all P < 0.05). Acupuncture achieves the positive and sustainable clinical effect on juvenile myopia, and the results of rotating manipulation are superior to that of lifting-thrusting manipulation. Age, basic vision and duration of sickness impact the clinical efficacy.

Rotation and decentration of an undersized plate-haptic trifocal toric intraocular lens in an eye with moderate myopia.

PubMed

Giers, Bert C; Khoramnia, Ramin; Weber, Lea F; Tandogan, Tamer; Auffarth, Gerd U

2016-03-01

We present the case of a 56-year-old woman with moderate myopia and bilateral cataract who had cataract extraction and intraocular lens (IOL) implantation. Due to the patient's desire for spectacle independence, a trifocal IOL with toric correction for astigmatism was implanted. During the follow-up, it became obvious that the implanted IOL had rotated and tilted due to insufficient fixation in the large capsular bag of the myopic eye. An IOL explantation was therefore performed, and the original IOL was exchanged for a bifocal toric IOL with a larger overall diameter. Stable fixation of the IOL in the capsular bag was achieved, and after surgery in the second eye, the patient recovered good bilateral vision. This case illustrates the need for careful selection of IOL diameter and sizing even in patients with moderate myopia due to the potentially larger ocular dimensions in these patients. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Posterior chamber phakic intraocular lens implantation: comparative, multicentre study in 351 eyes with low-to-moderate or high myopia.

PubMed

Kamiya, Kazutaka; Shimizu, Kimiya; Igarashi, Akihito; Kitazawa, Yoshihiro; Kojima, Takashi; Nakamura, Tomoaki; Oka, Yoshitaka; Matsumoto, Rei

2018-02-01

To compare the clinical outcomes of posterior chamber phakic intraocular lens implantation with a central hole (Hole Implantable Collamer Lens (ICL), STAAR Surgical) for low-to-moderate myopia and for high myopia. This multicentre retrospective case series comprised 351 eyes of 351 consecutive patients undergoing ICL implantation. Eyes were divided into groups based on preoperative degree of myopia: group 1; 57 eyes, manifest spherical equivalent less than -6 dioptres (D), and group 2; 294 eyes, -6 D or more. Safety, efficacy, predictability, stability and adverse events were compared preoperatively; and at 1 day, 1 week and 1, 3, 6 and 12 months postoperatively, RESULTS: Uncorrected and corrected visual acuities were -0.17±0.14 and -0.21±0.10 logMAR in group 1, and -0.16±0.09 and -0.21±0.08 logMAR in group 2, 1 year postoperatively. In groups 1 and 2, 98% and 99% of eyes were within 1.0 D of the targeted correction. Manifest refraction changes of -0.12±0.34 D (group 1) and -0.18±0.43 D (group 2) occurred from 1 day to 1 year. ICL exchanges were necessary in two eyes (0.7%) in group 2. No vision-threatening complications occurred at any time. The ICL performed well for the correction of both low-to-moderate myopia and high myopia throughout the 1-year observation period. The clinical outcomes of ICL implantation for low-to-moderate myopia are essentially equivalent to those for high myopia. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Finucane, B.; Jaeger, E.R.; Freitag, S.K.

We recently reported the finding of moderate to severe myopia in 6 of 10 patients with Smith-Magenis syndrome (SMS). To investigate the prevalence of SMS among mentally retarded people having myopia, we surveyed a cohort of patients residing at a facility for individuals with mental retardation (MR). Of 547 institutionalized individuals with MR, 72 (13.2%) had moderate to high myopia defined as a visual acuity of minus 3 diopters or more. It should be noted that our institution does not specifically select for people with visual impairment; rather, the facility serves people with a primary diagnosis of MR. Sixty-five ofmore » 72 (90.3%) myopic individuals identified were available for cytogenetic analysis. Seventeen (26.2%) of these patients had trisomy 21. Down syndrome (DS) is well known to be associated with eye abnormalities, including myopia. Of 48 individuals with moderate to high myopia not having DS, 5 (10.4%) were shown to have deletions of 17p11.2. This is a high prevalence considering the relative rarity of SMS. By contrast, in a randomized sample of 48 patients without significant myopia at the same facility, we found no individuals with deletion 17p11.2. We conclude that the diagnosis of SMS should be considered in any non-Down syndrome individual having MR and myopia, and that ophthalmologists serving people with MR should be made aware of this deletion syndrome. Furthermore, our results suggest that significant numbers of people having SMS could be identified through selective institutional screening of patients having a combination of MR and moderate to severe myopia.« less

Negative Lens–Induced Myopia in Infant Monkeys: Effects of High Ambient Lighting

PubMed Central

Smith, Earl L.; Hung, Li-Fang; Arumugam, Baskar; Huang, Juan

2013-01-01

Purpose. To determine whether high light levels, which have a protective effect against form-deprivation myopia, also retard the development of lens-induced myopia in primates. Methods. Hyperopic defocus was imposed on 27 monkeys by securing −3 diopter (D) lenses in front of one eye. The lens-rearing procedures were initiated at 24 days of age and continued for periods ranging from 50 to 123 days. Fifteen of the treated monkeys were exposed to normal laboratory light levels (∼350 lux). For the other 12 lens-reared monkeys, auxiliary lighting increased the illuminance to 25,000 lux for 6 hours during the middle of the daily 12 hour light cycle. Refractive development, corneal power, and axial dimensions were assessed by retinoscopy, keratometry, and ultrasonography, respectively. Data were also obtained from 37 control monkeys, four of which were exposed to high ambient lighting. Results. In normal- and high-light-reared monkeys, hyperopic defocus accelerated vitreous chamber elongation and produced myopic shifts in refractive error. The high light regimen did not alter the degree of myopia (high light: −1.69 ± 0.84 D versus normal light: −2.08 ± 1.12 D; P = 0.40) or the rate at which the treated eyes compensated for the imposed defocus. Following lens removal, the high light monkeys recovered from the induced myopia. The recovery process was not affected by the high lighting regimen. Conclusions. In contrast to the protective effects that high ambient lighting has against form-deprivation myopia, high artificial lighting did not alter the course of compensation to imposed defocus. These results indicate that the mechanisms responsible for form-deprivation myopia and lens-induced myopia are not identical. PMID:23557736

[Clinical risk factors for progressive myopia].

PubMed

Schaeffel, F

2012-08-01

The average worldwide frequency of myopia is approximately 30 % and is traditionally subdivided into school myopia and pathological myopia. A further distinction is made between progressive myopia and stationary myopia. There is a high correlation between the frequency of myopia and urbanization and training. Risk factors for development of myopia are close-up work, lack of outdoor activity, biometrical variables of the eye and genetic risk factors. Development of myopia can be positively influenced by peripheral focusing, increased exposure to light and in the future possibly pharmacologically.

Flicker parameters are different for suppression of myopia and hyperopia.

PubMed

Schwahn, H N; Schaeffel, F

1997-10-01

Axial eye growth rates in the chicken are controlled by local retinal image-processing circuits. These circuits quantify the loss of contrast for different spatial frequencies and promote axial eye growth rates in correlation with the amount of retinal image degradation ("deprivation myopia"). They also distinguish whether the plane of focus lies in front of or behind the retina. How the sign of defocus is detected still remains unclear. Cues from chromatic aberration are not important. In an attempt to isolate retinal circuits controlling the development of myopia or hyperopia, young chickens were raised in flickering light of different frequencies (12 and 6 Hz) and duty cycles (4-75%) produced by rotating chopper disks. The effects of flickering light on refractive errors and change in axial growth rates induced by translucent occluders or defocusing lenses were measured by infrared retinoscopy and A-scan ultrasound, respectively. Retinal electrical activity was evaluated by flicker ERG after matching flicker parameters and stimulation brightness at retinal surface. Changes in retinal and vitreal dopamine content caused by flicker in occluded and normal eyes were determined by HPLC-ECD. Strikingly, suppression of myopia occurred for similar flicker parameters, whether induced by translucent occluders ("deprivation") or negative lenses ("defocus"). The degree to which myopia was suppressed was correlated with the duration of flicker dark phase and with the ERG amplitude. In contrast, suppression of hyperopia did not correlate with these parameters. We conclude that two different retinal circuits with different temporal characteristics are involved in the processing of hyperopic defocus/deprivation and of myopic defocus, the first one dependent on flicker ERG amplitude. However, we did not find any correlation between the rate of dopamine release and the degree of inhibition of deprivation myopia in flickering light.

The longitudinal orthokeratology research in children (LORIC) in Hong Kong: a pilot study on refractive changes and myopic control.

PubMed

Cho, Pauline; Cheung, Sin Wan; Edwards, Marion

2005-01-01

Myopia is a common ocular disorder, and progression of myopia in children is of increasing concern. Modern overnight orthokeratology (ortho-k) is effective for myopic reduction and has been claimed to be effective in slowing the progression of myopia (myopic control) in children, although scientific evidence for this has been lacking. This 2 year pilot study was conducted to determine whether ortho-k can effectively reduce and control myopia in children. We monitored the growth of axial length (AL) and vitreous chamber depth (VCD) in 35 children (7-12 years of age), undergoing ortho-k treatment and compared the rates of change with 35 children wearing single-vision spectacles from an earlier study (control). For the ortho-k subjects, we also determined the changes in corneal curvature and the relationships with changes of refractive errors, AL and VCD. The baseline spherical equivalent refractive errors (SER), the AL, and VCD of the ortho-k and control subjects were not statistically different. All the ortho-k subjects found post-ortho-k unaided vision acceptable in the daytime. The residual SER at the end of the study was -0.18 +/- 0.69 D (dioptre) and the reduction (less myopic) in SER was 2.09 +/- 1.34 D (all values are mean +/- SD). At the end of 24 months, the increases in AL were 0.29 +/- 0.27 mm and 0.54 +/- 0.27 mm for the ortho-k and control groups, respectively (unpaired t test; p = 0.012); the increases in VCD were 0.23 +/- 0.25 mm and 0.48 +/- 0.26 mm for the ortho-k and control groups, respectively (p = 0.005). There was significant initial corneal flattening in the ortho-k group but no significant relationships were found between changes in corneal power and changes in AL and VCD. Ortho-k can have both a corrective and preventive/control effect in childhood myopia. However, there are substantial variations in changes in eye length among children and there is no way to predict the effect for individual subjects.

Risk Factors for Central Serous Chorioretinopathy: Multivariate Approach in a Case-Control Study.

PubMed

Chatziralli, Irini; Kabanarou, Stamatina A; Parikakis, Efstratios; Chatzirallis, Alexandros; Xirou, Tina; Mitropoulos, Panagiotis

2017-07-01

The purpose of this prospective study was to investigate the potential risk factors associated independently with central serous retinopathy (CSR) in a Greek population, using multivariate approach. Participants in the study were 183 consecutive patients diagnosed with CSR and 183 controls, matched for age. All participants underwent complete ophthalmological examination and information regarding their sociodemographic, clinical, medical and ophthalmological history were recorded, so as to assess potential risk factors for CSR. Univariate and multivariate analysis was performed. Univariate analysis showed that male sex, high educational status, high income, alcohol consumption, smoking, hypertension, coronary heart disease, obstructive sleep apnea, autoimmune disorders, H. pylori infection, type A personality and stress, steroid use, pregnancy and hyperopia were associated with CSR, while myopia was found to protect from CSR. In multivariate analysis, alcohol consumption, hypertension, coronary heart disease and autoimmune disorders lost their significance, while the remaining factors were all independently associated with CSR. It is important to take into account the various risk factors for CSR, so as to define vulnerable groups and to shed light into the pathogenesis of the disease.

Age of onset of myopia predicts risk of high myopia in later childhood in myopic Singapore children.

PubMed

Chua, Sharon Y L; Sabanayagam, Charumathi; Cheung, Yin-Bun; Chia, Audrey; Valenzuela, Robert K; Tan, Donald; Wong, Tien-Yin; Cheng, Ching-Yu; Saw, Seang-Mei

2016-07-01

To investigate the effect of age of myopia onset on the severity of myopia later in life among myopic children. In this prospective study, school children aged 7-9 years from the Singapore Cohort Of the Risk factors for Myopia (SCORM) were followed up till 11 years (n = 928). Age of myopia onset was defined either through questionnaire at baseline (age 7-9 years) or subsequent annual follow-up visits. Age of onset of myopia was a surrogate indicator of duration of myopia progression till age 11 years. Cycloplegic refraction and axial length were measured at every annual eye examination. High myopia was defined as spherical equivalent of ≤-5.0 D. A questionnaire determined the other risk factors. In multivariable regression models, younger age of myopia onset (per year decrease) or longer duration of myopia progression was associated with high myopia (odds ratio (OR) = 2.86; 95% CI: 2.39 to 3.43), more myopic spherical equivalent (regression coefficient (β) = -0.86 D; 95% CI: -0.93 to -0.80) and longer axial length (β = 0.28 mm; 95% CI: 0.24 to 0.32) at aged 11 years, after adjusting for gender, race, school, books per week and parental myopia. In Receiver Operating Curve (ROC) analyses, age of myopia onset alone predicted high myopia by 85% (area under the curve = 0.85), while the addition of other factors including gender, race, school, books per week and parental myopia only marginally improved this prediction (area under the curve = 0.87). Age of myopia onset or duration of myopia progression was the most important predictor of high myopia in later childhood in myopic children. Future trials to retard the progression of myopia to high myopia could focus on children with younger age of myopia onset or with longer duration of myopia progression. © 2016 The Authors Ophthalmic & Physiological Optics © 2016 The College of Optometrists.

Cognitive-analytical therapy for a patient with functional neurological symptom disorder-conversion disorder (psychogenic myopia): A case study.

PubMed

Nasiri, Hamid; Ebrahimi, Amrollah; Zahed, Arash; Arab, Mostafa; Samouei, Rahele

2015-05-01

Functional neurological symptom disorder commonly presents with symptoms and defects of sensory and motor functions. Therefore, it is often mistaken for a medical condition. It is well known that functional neurological symptom disorder more often caused by psychological factors. There are three main approaches namely analytical, cognitive and biological to manage conversion disorder. Any of such approaches can be applied through short-term treatment programs. In this case, study a 12-year-old boy with the diagnosed functional neurological symptom disorder (psychogenic myopia) was put under a cognitive-analytical treatment. The outcome of this treatment modality was proved successful.

Myopia and cognitive dysfunction among elderly Chinese adults: a propensity score matching analysis.

PubMed

Sun, Hong-Peng; Liu, Hu; Xu, Yong; Pan, Chen-Wei

2016-03-01

The association between myopia and cognitive dysfunction among elderly adults was assessed by applying a Propensity Score Matching (PSM) approach. This is a statistical method which allows investigators to estimate causal treatment effects using observational or nonrandomised data. The study was designed as a community-based cross-sectional study based on a Chinese cohort aged 60 years or older in China. Objective refraction was measured using an autorefractor and subjective refraction was used to refine vision, using the results of the objective refraction as the starting point. Myopia was defined as a spherical equivalent value of less than -0.50 dioptre (D) in the right eye. The Abbreviated Mental Test (AMT) was used for cognitive assessment. The propensity scores for myopia were formulated using 13 potential confounders. We matched the propensity scores for subjects with and without myopia within a caliper of 0.01 of logit function of propensity scores. About 4123 elderly adults who successfully completed the AMT were included in this analysis. The odds ratio (OR) of cognitive dysfunction for myopia before matching was 1.98 (95% confidence interval [CI] 1.61, 2.44; p < 0.001). There were significant covariate imbalances between comparison groups and after propensity score matching, covariate imbalance was significantly reduced. After propensity score matching, the OR of cognitive dysfunction was marginally significant and the magnitude of association was reduced (OR: 1.31 95% CI 1.00, 1.71; p = 0.05). Traditional multivariate logistic regression modelling found an OR of 1.52 (95% CI 1.23, 2.06; p < 0.001) after adjusting for the 13 potential confounders. Myopia was associated with a higher prevalence of cognitive dysfunction among elderly Chinese aged 60 years or older in China. The PSM approach may be a useful method to address selection bias in observational studies when randomised trials cannot ethically be conducted. © 2015 The Authors Ophthalmic & Physiological Optics © 2015 The College of Optometrists.

Risk Factors for High Myopia in Koreans: The Korea National Health and Nutrition Examination Survey.

PubMed

Hwang, Ho Sik; Chun, Min Young; Kim, Jin Sun; Oh, Bumjo; Yoo, Sang Ho; Cho, Bum-Joo

2018-05-02

To investigate risk factors for high myopia in the general Korean population. In this nationwide population study, the dataset of the Korea National Health and Nutrition Examination Survey 2008-2012 was analyzed. The study cohort included 11 703 participants, aged 25-49 years, who underwent neither refractive nor cataract surgery. The association between demographic, socioeconomic, behavioral, and systemic variables and high myopia was investigated. The mean participant age was 37.9 ± 6.8 years, and the prevalence of high myopia ≤-6.0D was 7.0 ± 0.3% in the study population. The right eyes (-1.76 ± 0.03 D) were more myopic than the left eyes (-1.70 ± 0.03 D; P < 0.001). In multivariate logistic regression analysis, high myopia was associated with age (odds ratio [OR], 0.97 per 1 year-increase) and female sex (OR, 1.24). Other identified risk factors included education level ≥ university graduation (OR, 1.91), the presence of hypertension (OR, 1.69), and serum glucose level (OR, 1.01 per 1 mg/dL). Sunlight exposure of ≥5 h/day (OR, 0.67) and serum 25-hydroxyvitamin D level (OR, 0.97 per 1 ng/mL) showed protective effect against high myopia. High myopia is associated with younger age, female sex, high education level, longer sunlight exposure, and some other systemic conditions.

Prevalence of and Factors Associated with Myopia in Inner Mongolia Medical Students in China, a cross-sectional study.

PubMed

Wang, Lan; Du, Maolin; Yi, He; Duan, Shengyun; Guo, Wenfang; Qin, Peng; Hao, Zhihui; Sun, Juan

2017-04-24

To further explore characteristics of myopia and changes in factors associated with myopia among students at Inner Mongolia Medical University. Two cross-sectional censuses were conducted in 2011 and 2013. Participants were medical students residing on campus in 2011 and 2013. Logistic regression analysis was performed to ascertain associations with basic information, genetic factors, environmental factors. The χ 2 test was used to test for differences in prevalence between 2011 and 2013. Prevalence was calculated at various myopia occurrence times among different parental myopia statuses. A total of 11,138 students enrolled from 2007 to 2012 completed the questionnaire. The prevalence of myopia in 2011 and 2013 was 70.50% and 69.21%, respectively, no statistically significant difference existed between the two censuses (p = 0.12). Both censuses were completed by 1015 students. There were no differences among the various year of study in 2011 or 2013. Myopic prevalence increased with an increased number of myopic parents: the prevalence if both parents were myopic was over 90%, nearly 80% if one parent was myopic, and less than 70% with non-myopic parents (p < 0.001). Myopic occurrence ranked from earliest to latest was in kindergarten and primary school when both parents were myopic, in middle school when one parent was myopic, and in university when no parent was myopic. Students staying up late, using a computer more than 3 h per day, not performing eye exercises, using eye drops, and rubbing the eyes at high risk for myopia. Myopic status was stable during the university period. Genetic factors play a major role in myopia. Protective measures are useful for university students.

Childhood febrile illness and the risk of myopia in UK Biobank participants.

PubMed

Guggenheim, J A; Williams, C

2016-04-01

Historical reports suggest febrile illness during childhood is a risk factor for myopia. The establishment of the UK Biobank provided a unique opportunity to investigate this relationship. We studied a sample of UK Biobank participants of White ethnicity aged 40-69 years old who underwent autorefraction (N=91 592) and were classified as myopic (≤-0.75 Dioptres (D)), highly myopic (≤-6.00 D), or non-myopic (>-0.75 D). Self-reported age at diagnosis of past medical conditions was ascertained during an interview with a nurse at a Biobank assessment centre. Logistic regression analysis was used to calculate the odds ratio (OR) for myopia or high myopia associated with a diagnosis before age 17 years of each of nine febrile illnesses, after adjusting for potential confounders (age, sex, highest educational qualification, and birth order). Rubella, mumps, and pertussis were associated with myopia: rubella, OR=1.38, 95% CI: 1.03-1.85, P=0.030; mumps, OR=1.32, 95% CI: 1.07-1.64, P=0.010; and pertussis, OR=1.39, 95% CI 1.03-1.87, P=0.029. Measles, rubella, and pertussis were associated with high myopia: measles, OR=1.48, 95% CI: 1.07-2.07, P=0.019; rubella, OR=1.94, 95% CI: 1.12-3.35, P=0.017; and pertussis, OR=2.15, 95% CI: 1.24-3.71, P=0.006. The evidence did not support an interaction between education and febrile illness in explaining the above risks. A history of childhood measles, rubella, or pertussis was associated with high myopia, whereas a history of childhood rubella, mumps, or pertussis was associated with any myopia. The reasons for these associations are unclear.

Interactions between biomaterials and the sclera: Implications on myopia progression

NASA Astrophysics Data System (ADS)

Su, James

Myopia prevalence has steadily climbed worldwide in recent decades with the most dramatic impact in East Asian countries. Treatments such as eyeglasses, contact lenses, and laser surgery for the refractive error are widely available, but none cures the underlying cause. In progressive high myopia, invasive surgical procedures using a scleral buckle for mechanical support are performed since the patient is at risk of becoming blind. The treatment outcome is highly dependent on the surgeon's skills and the patient's myopia progression rate, with limited choices in buckling materials. This dissertation, in four main studies, represents efforts made to control high myopia progression through the exploration and development of biomaterials that influence scleral growth. First, mRNA expression levels of the chick scleral matrix metalloproteinases, tissue-inhibitor of matrix metalloproteinases, and transforming growth factor-beta 2 were assessed for temporal and defocus power effects. The first study elucidated the roles that these factors play in scleral growth regulation and suggested potential motifs that can be incorporated in future biomaterials design. Second, poly(vinyl-pyrrolidone) as injectable gels and poly(2-hydroxyethyl methacrylate) as solid strips were implanted in chicks to demonstrate the concept of posterior pole scleral reinforcements. This second study found that placing appropriate biomaterials at the posterior pole of the eye could directly influence scleral remodeling by interacting with the host cells. Both studies advanced the idea that scleral tissue remodeling could be potentially controlled by well-designed biomaterials. These findings led to the exploration of biomimetic hydrogels comprising enzymatically-degradable semi-interpenetrating polymer networks (edsIPNs) to determine their biocompatibility and effects on the chick posterior eye wall. This third study demonstrated the feasibility of stimulating scleral growth by applying biomimetic injectable materials. Fourth, the muscarinic antagonist drug, atropine, was encapsulated within the edsIPNs and delivered to the chick eye posterior pole to evaluate the local effect of atropine release. This fourth study offered an alternative method of ocular drug delivery for treatment of myopia, with the potential to elucidate the actual location of the inhibitive effect of atropine on myopia progression. In summary, this dissertation contributes to the design and use of biomaterials specific to myopia therapy and adds novel insights to scleral tissue engineering.

Risk factors for refractive errors in primary school children (6-12 years old) in Nakhon Pathom Province.

PubMed

Yingyong, Penpimol

2010-11-01

Refractive error is one of the leading causes of visual impairment in children. An analysis of risk factors for refractive error is required to reduce and prevent this common eye disease. To identify the risk factors associated with refractive errors in primary school children (6-12 year old) in Nakhon Pathom province. A population-based cross-sectional analytic study was conducted between October 2008 and September 2009 in Nakhon Pathom. Refractive error, parental refractive status, and hours per week of near activities (studying, reading books, watching television, playing with video games, or working on the computer) were assessed in 377 children who participated in this study. The most common type of refractive error in primary school children was myopia. Myopic children were more likely to have parents with myopia. Children with myopia spend more time at near activities. The multivariate odds ratio (95% confidence interval)for two myopic parents was 6.37 (2.26-17.78) and for each diopter-hour per week of near work was 1.019 (1.005-1.033). Multivariate logistic regression models show no confounding effects between parental myopia and near work suggesting that each factor has an independent association with myopia. Statistical analysis by logistic regression revealed that family history of refractive error and hours of near-work were significantly associated with refractive error in primary school children.

Variant myopia: A new presentation?

PubMed Central

Hussaindeen, Jameel Rizwana; Anand, Mithra; Sivaraman, Viswanathan; Ramani, Krishna Kumar; Allen, Peter M

2018-01-01

Purpose: Variant myopia (VM) presents as a discrepancy of >1 diopter (D) between subjective and objective refraction, without the presence of any accommodative dysfunction. The purpose of this study is to create a clinical profile of VM. Methods: Fourteen eyes of 12 VM patients who had a discrepancy of >1D between retinoscopy and subjective acceptance under both cycloplegic and noncycloplegic conditions were included in the study. Fourteen eyes of 14 age- and refractive error-matched participants served as controls. Potential participants underwent a comprehensive orthoptic examination followed by retinoscopy (Ret), closed-field autorefractor (CA), subjective acceptance (SA), choroidal and retinal thickness, ocular biometry, and higher order spherical aberrations measurements. Results: In the VM eyes, a statistically and clinically significant difference was noted between the Ret and CA and Ret and SA under both cycloplegic and noncycloplegic conditions (multivariate repeated measures analysis of variance, P < 0.0001). A statistically significant difference was observed between the VM eyes, non-VM eyes, and controls for choroidal thickness in all the quadrants (Univariate ANOVA P < 0.05). The VM eyes had thinner choroids (197.21 ± 13.04 μ) compared to the non-VM eyes (249.25 ± 53.70 μ) and refractive error-matched controls (264.62 ± 12.53 μ). No statistically significant differences between groups in root mean square of total higher order aberrations and spherical aberration were observed. Conclusion: Accommodative etiology does not play a role in the refractive discrepancy seen in individuals with the variant myopic presentation. These individuals have thinner choroids in the eye with variant myopic presentation compared to the fellow eyes and controls. Hypotheses and clinical implications of variant myopia are discussed. PMID:29785987

Clinical outcomes of wavefront-guided laser in situ keratomileusis: 6-month follow-up.

PubMed

Aizawa, Daisuke; Shimizu, Kimiya; Komatsu, Mari; Ito, Misae; Suzuki, Masanobu; Ohno, Koji; Uozato, Hiroshi

2003-08-01

To evaluate the clinical outcomes 6 months after wavefront-guided laser in situ keratomileusis (LASIK) for myopia in Japan. Department of Ophthalmology, Sanno Hospital, Tokyo, Japan. This prospective study comprised 22 eyes of 12 patients treated with wavefront-guided LASIK who were available for evaluation at 6 months. The mean patient age was 31.2 years +/- 8.4 (SD) (range 23 to 50 years), and the mean preoperative spherical equivalent refraction was -7.30 +/- 2.72 diopters (D) (range -2.75 to -11.88 D). In all cases, preoperative wavefront analysis was performed with a Hartmann-Shack aberrometer and the Technolas 217z flying-spot excimer laser system (Bausch & Lomb) was used with 1.0 mm and 2.0 mm spot sizes and an active eye tracker with a 120 Hz tracking rate. The clinical outcomes of wavefront-guided LASIK were evaluated in terms of safety, efficacy, predictability, stability, complications, and preoperative and postoperative aberrations. At 6 months, 10 eyes had no change in best spectacle-correct visual acuity and 10 gained 1 or more lines. The safety index was 1.11 and the efficacy index, 0.82. Slight undercorrections were observed in highly myopic eyes. In all eyes, the postoperative refraction tended slightly toward myopia for 3 months and stabilized after that. No complication such as epithelial ingrowth, diffuse lamellar keratitis, or infection was observed. Comparison of the preoperative and postoperative aberrations showed that 2nd-order aberrations decreased and higher-order aberrations increased. In the 3rd order, aberrations increased in the high-myopia group (-6.0 D or worse) and decreased in the low to moderate-myopia group (better than -6.0 D). Wavefront-guided LASIK was a good option for refractive surgery, although a longer follow-up in a larger study is required.

[Regularities of the refractive genesis of school myopia and criteria for its prediction].

PubMed

Onufriĭchuk, O N; Rozenblium, Iu Z

2007-01-01

The paper provides the data of a 2-year monitoring of ocular refraction in 327 consecutive 10-14-year-old schoolchildren (654 eyes) unrandomized under natural conditions and cycloplegia. The authors studied whether there was an association of refraction and its changes with absolute and relative accommodation, habitual accommodation tonicity, the length of the anteroposterior optic axis, and the presence of pseudomyopathy and astigmatism. Over 2 years, myopia occurred in 15.4% of the eyes, its degree increased from -0.88 (-1.37/-0.50) to -1.25 (-2.31/-0.62) diopters. Criteria for myopia prediction were identified. These included a relative accommodation reserve of less than 2.5 diopters, an anteroposterior optic axis length of more than 24.33 mm, a habitual accommodation tonicity of less than + 0.41 diopters, the presence of pseudomyopia (77.8% of cases), reversed astigmatism and underlying emmetropia. A mathematical model was constructed for prediction of myopia, the proportion of its correct prediction being 90.4%, which makes it possible to recommend for clinical application.

Primary angle closure glaucoma in a myopic kinship.

PubMed

Hagan, J C; Lederer, C M

1985-03-01

Three related myopic individuals with primary angle closure glaucoma are reported. They had true myopia and not pseudomyopia secondary to increased lenticular index of refraction. We believe one of these individuals (-8.62 spherical equivalent) to have the most myopic case of primary angle closure glaucoma reported in the literature. Although myopia is associated with anatomical factors that offer considerable protection from primary angle closure glaucoma, its presence does not eliminate the possibility of this disease. Laser iridectomy was effective in the treatment of these patients.

Effects of orthokeratology on the progression of low to moderate myopia in Chinese children.

PubMed

He, Mengmei; Du, Yaru; Liu, Qingyu; Ren, Chengda; Liu, Junling; Wang, Qianyi; Li, Li; Yu, Jing

2016-07-27

To investigate the effectiveness of orthokeratology (ortho-k) in reducing the development of myopia in Chinese children with low to moderate myopia. This was a retrospective study. In the ortho-k group, there were141 subjects, and the average age was (9.43 ± 1.10) years. The average spherical equivalent refractive error (SER) was (-2.74 ± 1.15)D, with examinations performed 1, 7, 30, and 90 days and 12 months after the patients started wearing ortho-k lenses. In the control group, there were 130 subjects, and the average age was (9.37 ± 1.00) years. The average SER was (-2.88 ± 1.39)D, with examinations performed every 6 months. Axial elongation, which is an important parameter reflecting the progression of myopia, was measured at baseline from the same IOLMaster each time by the same masked examiner and was compared between the groups after 1 year. The subjects were divided into two sub-groups according to age to further study the development of myopia at different ages. An unpaired t-test, paired t-test, Chi-square test and Spearman test were performed to analyze the data. After 1 year, the average axial elongation was (0.27 ± 0.17) mm in the ortho-k lens group and (0.38 ± 0.13) mm in the control group, with a significant difference between the groups (P < 0.001). Axial elongation was not correlated with SER but had a negative correlation with initial age (ortho-k group: r s = -0.309, p < 0.01; control group: r s = -0.472, p < 0.01). The percentages of individuals with fast myopic progression (axial elongation > 0.36 mm per year) were 38.0 % among younger children (7.00 to 9.40 years) and 24.3 % among older children (9.40 to 12.00 years), whereas the respective percentages were 76.5 and 12.9 % in the control group. When SER ranged from -5.0D to -6.0D, the axial elongation in the ortho-k group was 57.1 % slower than that in the control group. Ortho-k lenses are effective in controlling myopic progression in Chinese children, particularly in younger children and in children with higher myopia.

The effect of bright light on lens compensation in chicks.

PubMed

Ashby, Regan S; Schaeffel, Frank

2010-10-01

It has been shown that sunlight or bright indoor light can inhibit the development of deprivation myopia in chicks. It remains unclear whether light merely acts on deprivation myopia or, more generally, modulates the rate of emmetropization and its set point. This study was conducted to test how bright light interacts with compensation for imposed optical defocus. Furthermore, a dopamine antagonist was applied to test whether the protective effect of light is mediated by dopamine. Experiment A: Chicks monocularly wore either -7 or +7 D lenses for a period of 5 days, either under normal laboratory illuminance (500 lux, n = 12 and 16, respectively) or under high ambient illuminance (15,000 lux, n = 12 and 16). Experiment B: Chicks wore diffusers for a period of 4 days, either under normal laboratory illuminance (500 lux, n = 9) or high ambient illuminance (15,000 lux), with the bright-light group intravitreally injected daily with either the dopamine D(2) antagonist spiperone (500 μM, n = 9) or a vehicle solution (0.1% ascorbic acid, n = 9), with an untreated group serving as the control (n = 6). Axial length and refraction were measured at the commencement and cessation of all treatments. Exposure to high illuminances (15,000 lux) for 5 hours per day significantly slowed compensation for negative lenses, compared with that seen under 500 lux, although full compensation was still achieved. Compensation for positive lenses was accelerated by exposure to high illuminances but, again, the end point refraction was unchanged, compared with that of the 500-lux group. High illuminance also reduced deprivation myopia by roughly 60%, compared with that seen under 500 lux. This protective effect was abolished, however, by the daily injection of spiperone, but was unaffected by the injection of a vehicle solution. High illuminance levels reduce the rate of compensation for negative lenses and enhance the rate for positive lenses, but do not change the set point of emmetropization (target refraction). The retardation of myopia development by light is partially mediated by dopamine, as the injection of a dopamine antagonist abolishes the protective effect of light, at least in the case of deprivation myopia.

Relationship between visual field progression and baseline refraction in primary open-angle glaucoma.

PubMed

Naito, Tomoko; Yoshikawa, Keiji; Mizoue, Shiro; Nanno, Mami; Kimura, Tairo; Suzumura, Hirotaka; Umeda, Yuzo; Shiraga, Fumio

2016-01-01

To analyze the relationship between visual field (VF) progression and baseline refraction in Japanese patients with primary open-angle glaucoma (POAG) including normal-tension glaucoma. In this retrospective study, the subjects were patients with POAG who had undergone VF tests at least ten times with a Humphrey Field Analyzer (Swedish interactive thresholding algorithm standard, Central 30-2 program). VF progression was defined as a significantly negative value of mean deviation (MD) slope at the final VF test. Multivariate logistic regression models were applied to detect an association between MD slope deterioration and baseline refraction. A total of 156 eyes of 156 patients were included in this analysis. Significant deterioration of MD slope was observed in 70 eyes of 70 patients (44.9%), whereas no significant deterioration was evident in 86 eyes of 86 patients (55.1%). The eyes with VF progression had significantly higher baseline refraction compared to those without apparent VF progression (-1.9±3.8 diopter [D] vs -3.5±3.4 D, P=0.0048) (mean ± standard deviation). When subject eyes were classified into four groups by the level of baseline refraction applying spherical equivalent (SE): no myopia (SE > -1D), mild myopia (-1D ≥ SE > -3D), moderate myopia (-3D ≥ SE > -6D), and severe myopia (-6D ≥ SE), the Cochran-Armitage trend analysis showed a decreasing trend in the proportion of MD slope deterioration with increasing severity of myopia (P=0.0002). The multivariate analysis revealed that baseline refraction (P=0.0108, odds ratio [OR]: 1.13, 95% confidence interval [CI]: 1.03-1.25) and intraocular pressure reduction rate (P=0.0150, OR: 0.97, 95% CI: 0.94-0.99) had a significant association with MD slope deterioration. In the current analysis of Japanese patients with POAG, baseline refraction was a factor significantly associated with MD slope deterioration as well as intraocular pressure reduction rate. When baseline refraction was classified into four groups, MD slope in myopia groups was less deteriorated as compared to those in the emmetropic/hyperopic group.

More irregular eye shape in low myopia than in emmetropia.

PubMed

Tabernero, Juan; Schaeffel, Frank

2009-09-01

To improve the description of the peripheral eye shape in myopia and emmetropia by using a new method for continuous measurement of the peripheral refractive state. A scanning photorefractor was designed to record refractive errors in the vertical pupil meridian across the horizontal visual field (up to +/-45 degrees ). The setup consists of a hot mirror that continuously projects the infrared light from a photoretinoscope under different angles of eccentricity into the eye. The movement of the mirror is controlled by using two stepping motors. Refraction in a group of 17 emmetropic subjects and 11 myopic subjects (mean, -4.3 D; SD, 1.7) was measured without spectacle correction. For the analysis of eye shape, the refractive error versus the eccentricity angles was fitted with different polynomials (from second to tenth order). The new setup presents some important advantages over previous techniques: The subject does not have to change gaze during the measurements, and a continuous profile is obtained rather than discrete points. There was a significant difference in the fitting errors between the subjects with myopia and those with emmetropia. Tenth-order polynomials were required in myopic subjects to achieve a quality of fit similar to that in emmetropic subjects fitted with only sixth-order polynomials. Apparently, the peripheral shape of the myopic eye is more "bumpy." A new setup is presented for obtaining continuous peripheral refraction profiles. It was found that the peripheral retinal shape is more irregular even in only moderately myopic eyes, perhaps because the sclera lost some rigidity even at the early stage of myopia.

Form-Deprivation Myopia in Chick Induces Limited Changes in Retinal Gene Expression

PubMed Central

McGlinn, Alice M.; Baldwin, Donald A.; Tobias, John W.; Budak, Murat T.; Khurana, Tejvir S.; Stone, Richard A.

2007-01-01

Purpose Evidence has implicated the retina as a principal controller of refractive development. In the present study, the retinal transcriptome was analyzed to identify alterations in gene expression and potential signaling pathways involved in form-deprivation myopia of the chick. Methods One-week-old white Leghorn chicks wore a unilateral image-degrading goggle for 6 hours or 3 days (n = 6 at each time). Total RNA from the retina/(retinal pigment epithelium) was used for expression profiling with chicken gene microarrays (Chicken GeneChips; Affymetrix, Santa Clara, CA). To identify gene expression level differences between goggled and contralateral nongoggled eyes, normalized microarray signal intensities were analyzed by the significance analysis of microarrays (SAM) approach. Differentially expressed genes were validated by real-time quantitative reverse transcription–polymerase chain reaction (qPCR) in independent biological replicates. Results Small changes were detected in differentially expressed genes in form-deprived eyes. In chickens that had 6 hours of goggle wear, downregulation of bone morphogenetic protein 2 and connective tissue growth factor was validated. In those with 3 days of goggle wear, downregulation of bone morphogenetic protein 2, vasoactive intestinal peptide, preopro-urotensin II–related peptide and mitogen-activated protein kinase phosphatase 2 was validated, and upregulation of endothelin receptor type B and interleukin-18 was validated. Conclusions Form-deprivation myopia, in its early stages, is associated with only minimal changes in retinal gene expression at the level of the transcriptome. While the list of validated genes is short, each merits further study for potential involvement in the signaling cascade mediating myopia development. PMID:17652709

Myopia-What is Old and What is New?

PubMed

Schaeffel, Frank

2016-06-29

The recent "boom of myopia," described predominantly for East Asia, is assumed to result from increasingly demanding education programs that include extensive near work (and perhaps also extensive use of computers) and little exposure to bright light as found outdoors. Already in 1892, Hermann Cohn stated that the prevalence of myopia is related to the educational level which is related to the economic status of a country. It is not much appreciated that the rates of myopia were already high among school children in central Europe in the middle of the 19th century, as described by Hermann Cohn. From extensive research in recent times, three major approaches have emerged to interfere with myopia progression in children: (1) promoting exposure to bright light and enforce outdoor activity, (2) adapting/improving optical corrections and visual behavior to generate inhibitory signals for eye growth in the retina, and (3) applying atropine eye drops at low doses. However, Hermann Cohn had already proposed that low luminances during school work promote myopia development and requested that lighting in the classrooms needs to be at least "10 meter candles" (equivalent to an illuminance of 10 lux). Different from today, he explained the link between low light and myopia by shorter reading distances that he observed at low luminances of the reading surface (<1 cd/m). He suggested that short reading distances should be avoided in children and described several devices to control them. He further suggested that reading duration should be limited and urged myopes to choose professions that do not involve extensive near work. He also studied the effects of atropine against myopia but concluded that the side effects make it less useful than simply "3-4 weeks without reading." In summary, a number of his findings were re-discovered today, but they are now much better supported by data, and their interpretations have changed, at least in some aspects.

Postoperative Corneal Asphericity in Low, Moderate, and High Myopic Eyes After Transepithelial PRK Using a New Pulse Allocation.

PubMed

Lin, David T C; Holland, Simon P; Verma, Shwetabh; Hogden, John; Arba-Mosquera, Samuel

2017-12-01

To evaluate the postoperative asphericity in low, moderate, and high myopic eyes after combined transepithelial photorefractive keratectomy and SmartSurf ACE treatment (SCHWIND eye-tech-solutions GmbH, Kleinostheim, Germany). In this retrospective case series, the outcomes of myopic SmartSurf ACE were evaluated at 3 months postoperatively in 106 eyes and divided into low (less than -4.125 diopters [D]), moderate (-4.125 to -6.25 D), and high (more than -6.25 D) myopia groups. In all cases, standard examinations and preoperative and postoperative corneal topography (SCHWIND Sirius) were performed. The analysis comprised evaluating the change in asphericity versus planned correction, comparing expected and achieved postoperative asphericity for all eyes, and comparison of the three groups in terms of the preoperative and postoperatively expected and achieved asphericity. RESULTS At 3 months postoperatively, the low myopia group (n = 33) improved average negative asphericity (Q = -0.04 ± 0.17 preoperative vs -0.19 ± 0.20 postoperative, P < .05). The moderate myopia group (n = 35) maintained or slightly improved average negative asphericity (Q = -0.07 ± 0.14 preoperative vs -0.05 ± 0.24 postoperative, P = .35). For the high myopia group (n = 38), the eyes became more oblate compared to the preoperative status (Q = -0.09 ± 0.15 preoperative vs 0.62 ± 0.70 postoperative, P < .05). In terms of asphericity, the difference between the three groups was not statistically significant preoperatively (P > .10), but showed significant differences postoperatively (P < .007). The cohort's average preoperative corrected distance visual acuity was 0.01 ± 0.04 logMAR (range: 0.0 to 0.18 logMAR) and uncorrected distance visual acuity was 0.03 ± 0.08 logMAR (range: -0.12 to 0.40 logMAR) 3 months postoperatively. SmartSurf ACE maintained or slightly improved preoperative corneal asphericity for low to moderate myopic corrections (up to -6.00 D). This may provide advantages in the quality of vision and the onset of presbyopic symptoms after laser refractive surgery in myopic patients. [J Refract Surg. 2017;33(12):820-826.]. Copyright 2017, SLACK Incorporated.

Rapid, Accurate, and Non-Invasive Measurement of Zebrafish Axial Length and Other Eye Dimensions Using SD-OCT Allows Longitudinal Analysis of Myopia and Emmetropization

PubMed Central

Collery, Ross F.; Veth, Kerry N.; Dubis, Adam M.; Carroll, Joseph; Link, Brian A.

2014-01-01

Refractive errors in vision can be caused by aberrant axial length of the eye, irregular corneal shape, or lens abnormalities. Causes of eye length overgrowth include multiple genetic loci, and visual parameters. We evaluate zebrafish as a potential animal model for studies of the genetic, cellular, and signaling basis of emmetropization and myopia. Axial length and other eye dimensions of zebrafish were measured using spectral domain-optical coherence tomography (SD-OCT). We used ocular lens and body metrics to normalize and compare eye size and relative refractive error (difference between observed retinal radial length and controls) in wild-type and lrp2 zebrafish. Zebrafish were dark-reared to assess effects of visual deprivation on eye size. Two relative measurements, ocular axial length to body length and axial length to lens diameter, were found to accurately normalize comparisons of eye sizes between different sized fish (R2 = 0.9548, R2 = 0.9921). Ray-traced focal lengths of wild-type zebrafish lenses were equal to their retinal radii, while lrp2 eyes had longer retinal radii than focal lengths. Both genetic mutation (lrp2) and environmental manipulation (dark-rearing) caused elongated eye axes. lrp2 mutants had relative refractive errors of −0.327 compared to wild-types, and dark-reared wild-type fish had relative refractive errors of −0.132 compared to light-reared siblings. Therefore, zebrafish eye anatomy (axial length, lens radius, retinal radius) can be rapidly and accurately measured by SD-OCT, facilitating longitudinal studies of regulated eye growth and emmetropization. Specifically, genes homologous to human myopia candidates may be modified, inactivated or overexpressed in zebrafish, and myopia-sensitizing conditions used to probe gene-environment interactions. Our studies provide foundation for such investigations into genetic contributions that control eye size and impact refractive errors. PMID:25334040

Darkness and near work: myopia and its progression in third-year law students.

PubMed

Loman, Jane; Quinn, Graham E; Kamoun, Layla; Ying, Gui-Shuang; Maguire, Maureen G; Hudesman, David; Stone, Richard A

2002-05-01

To evaluate myopia prevalence, myopia progression, and various potential myopia risk factors in third-year law students. Cross-sectional study and survey. One hundred seventy-nine third-year law students at the University of Pennsylvania. We administered a questionnaire to assess the prevalence of myopia, myopia progression, and risk factors, including near work, family history, and daily light/dark exposure. We conducted a screening eye examination to ascertain myopia status. Myopia was defined as the mean spherical equivalent of the two eyes of 5.6 hours of darkness per day (95% vs. 80%, P = 0.07). To account for possible confounding effects of risk factors with myopia progression, logistic regression with categorization of the continuous exposure variables (hours of near work, sleep, and darkness) above or below median values weakened the near work association (odds ratio 1.8, 95% confidence interval 0.5-6.7, P = 0.35) but continued to identify darkness association with daily hours of darkness (odds ratio 4.8, 95% confidence interval 1.0 >/= 23.3, P < 0.05). Among the 77 students with myopia onset before college, those with

Animal models in myopia research.

PubMed

Schaeffel, Frank; Feldkaemper, Marita

2015-11-01

Our current understanding of the development of refractive errors, in particular myopia, would be substantially limited had Wiesel and Raviola not discovered by accident that monkeys develop axial myopia as a result of deprivation of form vision. Similarly, if Josh Wallman and colleagues had not found that simple plastic goggles attached to the chicken eye generate large amounts of myopia, the chicken model would perhaps not have become such an important animal model. Contrary to previous assumptions about the mechanisms of myopia, these animal models suggested that eye growth is visually controlled locally by the retina, that an afferent connection to the brain is not essential and that emmetropisation uses more sophisticated cues than just the magnitude of retinal blur. While animal models have shown that the retina can determine the sign of defocus, the underlying mechanism is still not entirely clear. Animal models have also provided knowledge about the biochemical nature of the signal cascade converting the output of retinal image processing to changes in choroidal thickness and scleral growth; however, a critical question was, and still is, can the results from animal models be applied to myopia in children? While the basic findings from chickens appear applicable to monkeys, some fundamental questions remain. If eye growth is guided by visual feedback, why is myopic development not self-limiting? Why does undercorrection not arrest myopic progression even though positive lenses induce myopic defocus, which leads to the development of hyperopia in emmetropic animals? Why do some spectacle or contact lens designs reduce myopic progression and others not? It appears that some major differences exist between animals reared with imposed defocus and children treated with various optical corrections, although without the basic knowledge obtained from animal models, we would be lost in an abundance of untestable hypotheses concerning human myopia. © 2015 Optometry Australia.

[Pathophysiology of myopia: nature versus nurture].

PubMed

Cassagne, M; Malecaze, F; Soler, V

2014-05-01

Myopia is the most frequent refractive disorder in the world. It has become a real Public Health problem, due to its frequency and to high myopia-related blinding complications. Myopic progression depends on genetic and environmental factors. Genetic studies have identified more than forty candidate genes that take part in pathophysiological pathways, from retinal phototransduction to axial lengthening via scleral remodelling. Environmental factors also influence scleral remodelling by way of visual perception. In the case of predominant attention to near tasks, a physiological feedback loop leads to axial growth. This phenomenon, called active emmetropization, is particularly obvious in animal models and in some human populations. To date, research has failed to identify a molecule common to all the implicated metabolic pathways which could be a target for an effective preventive treatment against myopic progression. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

The increasing prevalence of myopia in junior high school students in the Haidian District of Beijing, China: a 10-year population-based survey.

PubMed

Li, Yan; Liu, Jia; Qi, Pengcheng

2017-06-12

Myopia is a leading cause of preventable blindness. Although, multiple cross-sectional epidemiological studies have confirmed that there is a high prevalence of myopia in high school-aged students in China. However, few longitudinal studies have been performed to assess junior high school students. In the present study, we investigate changes in the prevalence of myopia in third year junior high school (grade 9) students in the Haidian District of Beijing, China, from 2006 to 2015. A retrospective, longitudinal cohort study was performed over 10 years. A total of 37,424 third-year middle school (grade 9) students from 8 junior high schools in Haidian district, Beijing, were included. Participants underwent a comprehensive ophthalmic examination in which they were evaluated using autorefraction under cycloplegia and submitted to retinoscopy to assess accuracy. According to the spherical equivalent refraction (SER) of the right eye, subjects were separated into the following groups: non-myopia, -0.5 ≤ SER diopters (D); low myopia, -3.0 ≤ SER < -0.5 D; moderate myopia, -6.0 ≤ SER < -3.0 D; and high myopia, SER > -6.0 D. The following characteristics were measured: refractive error; the proportion of subjects with non- myopia, low myopia, moderate myopia and high myopia; and the difference in the prevalence of myopia between male and female subjects. From 2006 to 2015, the prevalence of non-myopia (from 44.05% to 34.52%) and low myopia (from 32.27% to 20.73%) decreased, while the prevalence of moderate myopia (from 19.72% to 38.06%) and high myopia (from 3.96% to 6.69%) significantly increased. For refractive error, the worse eye was -2.23 ± 2.42 D (median, -1.75; range - 12.75 to +8.50) in 2006 and -3.13 ± 2.66 D (median, -2.75; range - 12.75 to +8.50) in 2015. When the entire population was considered, the overall prevalence of myopia increased from 55.95% in 2005 to 65.48% in 2015. There was a significant positive relationship between the year and the prevalence of myopia in both girls and boys. Girls were more likely than boys to have myopia (odds ratio, 1.43 [95% CI, 1.14-1.96]), especially moderate myopia, and the prevalence of moderate and high myopia were higher in girls than in boys. During the last 10 years, the prevalence of myopia significantly increased on an annual basis among third-year junior high school students in the Haidian District of Beijing, China. The total prevalence of myopia was significantly higher in girl than in boy participants. The refractive status of this age group deserves particular attention.

Effect of retinoic acid on the tight junctions of the retinal pigment epithelium-choroid complex of guinea pigs with lens-induced myopia in vivo

PubMed Central

WANG, SHA; LIU, SHUANGZHEN; MAO, JUNFENG; WEN, DAN

2014-01-01

Zonula occludens-1 (ZO-1) and occludin are important tight junction (TJ)-associated proteins, which are expressed in the retinal pigment epithelium (RPE)-choroid complex. Retinoic acid (RA) is a regulator of eye growth and may play an important role in forming functional TJs. The aim of this study was to detect the changes that occur in the expression of ZO-1 and occludin in the RPE-choroid complex of guinea pigs with lens-induced myopia (LIM), and to investigate the effect of RA on TJ-associated proteins in vivo. We developed an animal model of myopia by placing a −6.00 D negative lens on the right eyes of 3-week-old guinea pigs. The refractive error and axial length of the eye were measured on days 0, 3, 7 and 14. High-performance liquid chromatography (HPLC) was performed to detect the changes in endogenous RA in the RPE-choroid complex. The expression of ZO-1 and occludin was observed by immunofluorescence and assayed by western blot analysis. Additionally, 2 μl LE540 (2.5 μg/μl), an antagonist of RA receptors (RARs), was injected into the vitreous chamber of the eyes of guinea pigs with LIM and 2 μl phosphate-buffered saline (PBS) (2.5 μg/μl) were injected as a negative control. We observed no obvious change in RA, ZO-1 and occludin expression in the normal control group within 14 days. In the LIM and LIM plus PBS groups, the level of RA and the expression of ZO-1 and occludin in the RPE-choroid complex significantly increased within 14 days along with the development of myopia. However, the level of RA was inhibited and the expression of TJ-associated proteins decreased in the eyes of guinea pigs with LIM following the injection of LE540. Thus, we consider that the expression of ZO-1 and occludin is increased in the RPE-choroid complex during the development of myopia. This change in expression may be regulated by RA, a factor known to be involved in the regulation of eye growth. PMID:24535401

Effects of multifocal soft contact lenses used to slow myopia progression on quality of vision in young adults.

PubMed

Kang, Pauline; McAlinden, Colm; Wildsoet, Christine F

2017-02-01

To assess the effects of multifocal soft contact lenses (MF SCLs) used for myopia control on visual acuity (VA) and subjective quality of vision. Twenty-four young adult myopes had baseline high and low-contrast VAs and refractions measured and quality of vision assessed by the Quality of Vision (QoV) questionnaire with single vision SCLs. Additional VA and QoV questionnaire data were collected immediately after subjects were fitted with Proclear MF SCLs and again after a 2-week adaptation period of daily lens wear. Data were collected for two MF SCL designs, incorporating +1.50 and +3.00 D peripheral near additions, with a week washout period allowed between the two lens trials. High- and low-contrast VAs were initially reduced with both MF SCL designs, but subsequently improved to be not significantly reduced in the case of high-contrast VA by the end of the 2-week adaptation period. The quality of vision was also reduced, more so with the +3.00 D MF SCL. Quality of Vision (QoV) scores describing frequency, severity and bothersome nature of visual symptoms indicated symptoms worsening rather than resolving over the 2-week period, particularly so with the +3.00 D MF SCL. Low and high add MF SCLs adversely affected vision on initial insertion, with sustained effects on low-contrast VA and QoV scores but not high-contrast VA. Thus, high-contrast VA is not a suitable surrogate for quality of vision. In prescribing MF SCLs for myopia control, clinicians should educate patients about these effects on vision. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

[Epidemiology of myopia].

PubMed

Hopf, S; Pfeiffer, N

2017-01-01

Myopia is the most common cause for impaired vision in children and young adults with increasing tendency. Although myopia is hereditary, genetic findings do not explain the full extent of its recent increase. Epidemiologic studies are required to investigate the prevalence and incidence of this disease. The prevalence, incidence and progression of myopia with its economic impact are emphasized to review the distribution and consequences of the development and progression of myopia. A systematic literature search was conducted in MEDLINE. The global prevalence of myopia is currently 28.3 % and is dramatically increasing. In 2050, half of the world population will be affected. Myopia starts earlier and exhibits a peak prevalence in young Asian adults. High myopia indicates a similar development. Interventions to slow the development and progression of myopia are strongly required due to the medical and socio-economic drawbacks for the individuals and for society. Myopia is already a ubiquitous phenomenon in some parts of the world. One out of ten persons will be at a relevant risk of becoming blind as a result of myopia in the future. Preventive measures have not shown sweeping success.

Experimental murine myopia induces collagen type Iα1 (COL1A1) DNA methylation and altered COL1A1 messenger RNA expression in sclera

PubMed Central

Zhou, Xiangtian; Ji, Fengtao; An, Jianhong; Zhao, Fuxin; Shi, Fanjun; Huang, Furong; Li, Yuan; Jiao, Shiming; Yan, Dongsheng; Chen, Xiaoyan; Chen, JiangFan

2012-01-01

Purpose To investigate whether myopia development is associated with changes of scleral DNA methylation in cytosine-phosphate-guanine (CpG) sites in the collagen 1A1 (COL1A1) promoter and messenger RNA (mRNA) levels following murine form deprivation myopia. Methods Fifty-seven C57BL/6 mice (postnatal day 23) were randomly assigned to four groups: (1) monocular form deprivation (MD) in which a diffuser lens was placed over one eye for 28 days; (2) normal controls without MD; (3) MD recovery in which the diffuser lens was removed for seven days; and (4) MD recovery normal controls. The DNA methylation pattern in COL1A1 promoter and exon 1 was determined by bisulfite DNA sequencing, and the COL1A1 mRNA level in sclera was determined by quantitative PCR. Results MD was found to induce myopia in the treated eyes. Six CpG sites in the promoter and exon 1 region of COL1A1 were methylated with significantly higher frequency in the treated eyes than normal control eyes (p<0.05), with CpG island methylation in MD-contralateral eyes being intermediate. Consistent with the CpG methylation, scleral COL1A1 mRNA was reduced by 57% in the MD-treated eyes compared to normal controls (p<0.05). After seven days of MD recovery, CpG methylation was significantly reduced (p=0.01). The methylation patterns returned to near normal level in five CpG sites, but the sixth was hypomethylated compared to normal controls. Conclusions In parallel with the development of myopia and the reduced COL1A1 mRNA, the frequency of methylation in CpG sites of the COL1A1 promoter/exon 1 increased during MD and returned to near normal during recovery. Thus, hypermethylation of CpG sites in the promoter/exon 1 of COL1A1 may underlie reduced collagen synthesis at the transcriptional level in myopic scleras. PMID:22690110

[Deformations of the vertebral column in the visually impaired schoolchildren presenting with complicated high myopia and the possibilities for its correction].

PubMed

Egorova, T S; Smirnova, T S; Romashin, O V; Egorova, I V

2016-01-01

Complicated high myopia is one of the leading causes responsible for the disablement in the children associated with visual impairment especially when it is combined with other pathological conditions and abnormalities among which are disorders of the musculoskeletal system. In the present study, we for the first time examined visually impaired schoolchildren (n=44) who suffered from high myopia complications making use of the computed optical topographer for the evaluation of the state of their vertebral column. The control group consisted of 60 children attending a secondary school. The study revealed various deformations of the musculoskeletal system including scoliosis, misalignment of the pelvis, kyphosis, hyperlordosis, torsion, platypodia, deformation of the lower extremities and the chest. These deformations were more pronounced in the visually impaired schoolchildren in comparison with the children of the same age comprising the control group (p<0,05). It is concluded that the assessment of the state of the vertebral column with the use of the apparatus yields an important information for the elaboration and application of a series of measures for the timely provision of medical assistance needed for the comprehensive rehabilitation of the visually impaired schoolchildren presenting with high myopia complications.

Multiple Free Internal Limiting Membrane Flap Insertion in the Treatment of Macular Hole-Associated Retinal Detachment in High Myopia.

PubMed

Chen, San-Ni; Hsieh, Yi-Ting; Yang, Chung-May

2018-06-06

The aim of this paper was to evaluate the efficacy of multiple free internal limiting membrane (ILM) flap insertion in the management of macular hole-associated retinal detachment in high myopia. Eyes receiving operation for macular hole-associated retinal detachment were retrospectively recruited. Those in the study group received ILM peeling and multiple free ILM flap insertion, while those in the control group received ILM peeling only. Postoperative anatomical outcomes and best-corrected visual acuity were compared between the 2 groups. Twenty-seven eyes of 27 patients were recruited in this study (13 in the study group, 14 in the control group). After the operation, the retina was reattached in all cases in both groups. The macular hole closure rate was 100% in the study group but only 42.9% in the control group (adjusted p < 0.001). The eyes in the study group had better visual improvement (logMAR -0.58 ± 0.43) than those in the control group (logMAR -0.31 ± 0.50) with borderline significance (adjusted p = 0.078). For macular hole-associated retinal detachment in highly myopic eyes, the multiple free ILM flap insertion technique offers an effective way to close macular holes. Whether this result also means better visual outcome remains to be seen. © 2018 S. Karger AG, Basel.

Heritability of lenticular myopia in English Springer spaniels.

PubMed

Kubai, Melissa A; Labelle, Amber L; Hamor, Ralph E; Mutti, Donald O; Famula, Thomas R; Murphy, Christopher J

2013-11-08

We determined whether naturally-occurring lenticular myopia in English Springer spaniels (ESS) has a genetic component. Streak retinoscopy was performed on 226 related ESS 30 minutes after the onset of pharmacologic mydriasis and cycloplegia. A pedigree was constructed to determine relationships between affected offspring and parents. Estimation of heritability was done in a Bayesian analysis (facilitated by the MCMCglmm package of R) of refractive error in a model, including terms for sex and coat color. Myopia was defined as ≤-0.5 diopters (D) spherical equivalent. The median refractive error for ESS was 0.25 D (range, -3.5 to +4.5 D). Median age was 0.2 years (range, 0.1-15 years). The prevalence of myopia in related ESS was 19% (42/226). The ESS had a strong correlation (r = 0.95) for refractive error between the two eyes. Moderate heritability was present for refractive error with a mean value of 0.29 (95% highest probability density, 0.07-0.50). The distribution of refractive error, and subsequently lenticular myopia, has a moderate genetic component in ESS. Further investigation of genes responsible for regulation of the development of refractive ocular components in canines is warranted.

Bidirectional Expression of Metabolic, Structural, and Immune Pathways in Early Myopia and Hyperopia

PubMed Central

Riddell, Nina; Giummarra, Loretta; Hall, Nathan E.; Crewther, Sheila G.

2016-01-01

Myopia (short-sightedness) affects 1.45 billion people worldwide, many of whom will develop sight-threatening secondary disorders. Myopic eyes are characterized by excessive size while hyperopic (long-sighted) eyes are typically small. The biological and genetic mechanisms underpinning the retina's local control of these growth patterns remain unclear. In the present study, we used RNA sequencing to examine gene expression in the retina/RPE/choroid across 3 days of optically-induced myopia and hyperopia induction in chick. Data were analyzed for differential expression of single genes, and Gene Set Enrichment Analysis (GSEA) was used to identify gene sets correlated with ocular axial length and refraction across lens groups. Like previous studies, we found few single genes that were differentially-expressed in a sign-of-defocus dependent manner (only BMP2 at 1 day). Using GSEA, however, we are the first to show that more subtle shifts in structural, metabolic, and immune pathway expression are correlated with the eye size and refractive changes induced by lens defocus. Our findings link gene expression with the morphological characteristics of refractive error, and suggest that physiological stress arising from metabolic and inflammatory pathway activation could increase the vulnerability of myopic eyes to secondary pathologies. PMID:27625591

Looking into aqueous humor through metabolomics spectacles - exploring its metabolic characteristics in relation to myopia.

PubMed

Barbas-Bernardos, Cecilia; Armitage, Emily G; García, Antonia; Mérida, Salvador; Navea, Amparo; Bosch-Morell, Francisco; Barbas, Coral

2016-08-05

Aqueous humor is the transparent fluid found in the anterior chamber of the eye that provides the metabolic requirements to the avascular tissues surrounding it. Despite the fact that metabolomics could be a powerful tool in the characterization of this biofluid and in revealing metabolic signatures of common ocular diseases such as myopia, it has never to our knowledge previously been applied in humans. In this research a novel method for the analysis of aqueous humor is presented to show its application in the characterization of this biofluid using CE-MS. The method was extended to a dual platform method (CE-MS and LC-MS) in order to compare samples from patients with different severities of myopia in order to explore the disease from the metabolic phenotype point of view. With this method, a profound knowledge of the metabolites present in human aqueous humor has been obtained: over 40 metabolites were reproducibly and simultaneously identified from a low volume of sample by CE-MS, including among others, a vast number of amino acids and derivatives. When this method was extended to study groups of patients with high or low myopia in both CE-MS and LC-MS, it has been possible to identify over 20 significantly different metabolite and lipid signatures that distinguish patients based on the severity of myopia. Among these, the most notable higher abundant metabolites in high myopia were aminooctanoic acid, arginine, citrulline and sphinganine while features of low myopia were aminoundecanoic acid, dihydro-retinoic acid and cysteinylglycine disulfide. This dual platform approach offered complementarity such that different metabolites were detected in each technique. Together the experiments presented provide a whelm of valuable information about human aqueous humor and myopia, proving the utility of non-targeted metabolomics for the first time in analyzing this type of sample and the metabolic phenotype of this disease. Copyright © 2016 Elsevier B.V. All rights reserved.

Low serum vitamin D is associated with axial length and risk of myopia in young children.

PubMed

Tideman, J Willem L; Polling, Jan Roelof; Voortman, Trudy; Jaddoe, Vincent W V; Uitterlinden, André G; Hofman, Albert; Vingerling, Johannes R; Franco, Oscar H; Klaver, Caroline C W

2016-05-01

The aim of the study was to investigate the relationship between serum 25(OH)D levels and axial length (AL) and myopia in 6-year-old children. A total of 2666 children aged 6 years participating in the birth-cohort study Generation R underwent a stepwise eye examination. First, presenting visual acuity (VA) and AL were performed. Second, automated cycloplegic refraction was measured if LogMAR VA > 0.1. Serum 25-hydroxyvitamin D [25(OH)D] was determined from blood using liquid chromatography/tandem mass spectrometry. Vitamin D related SNPs were determined with a SNP array; outdoor exposure was assessed by questionnaire. The relationships between 25(OH)D and AL or myopia were investigated using linear and logistic regression analysis. Average 25(OH)D concentration was 68.8 nmol/L (SD ± 27.5; range 4-211); average AL 22.35 mm (SD ± 0.7; range 19.2-25.3); and prevalence of myopia 2.3 % (n = 62). After adjustment for covariates, 25(OH)D concentration (per 25 nmol/L) was inversely associated with AL (β -0.043; P < 0.01), and after additional adjusting for time spent outdoors (β -0.038; P < 0.01). Associations were not different between European and non-European children (β -0.037 and β -0.039 respectively). Risk of myopia (per 25 nmol/L) was OR 0.65 (95 % CI 0.46-0.92). None of the 25(OH)D related SNPs showed an association with AL or myopia. Lower 25(OH)D concentration in serum was associated with longer AL and a higher risk of myopia in these young children. This effect appeared independent of outdoor exposure and may suggest a more direct role for 25(OH)D in myopia pathogenesis.

Is there a link between passive smoke exposure and early-onset myopia in preschool Asian children?

PubMed

Chua, Sharon Yu Lin; Ikram, Mohammad Kamran; Tan, Chuen Seng; Stone, Richard A; Cai, Shirong; Gluckman, Peter D; Yap, Seng Chong; Yap, Fabian; Wong, Tien-Yin; Ngo, Cheryl S; Saw, Seang-Mei

2016-07-01

To investigate the association of passive tobacco smoke exposure with early-onset myopia among three-year-old children in Singapore. Pregnant mothers who attended their first trimester clinic at two major maternity units were recruited into the GUSTO birth cohort. The current analysis comprised 572 three-year-old children, who underwent cycloplegic autorefraction and axial length (AL) measurements. Myopia was defined as spherical equivalent (SE) of ≤-0.50 dioptres (D). Either parent completed questionnaires describing their child's exposure to passive smoke at six months, one and two years of age. There were 197 children (36.2%) who were exposed to passive smoke from birth to before six months. Compared to non-exposed children, children exposed to any passive smoke from birth to before six months experienced greater myopia prevalence (adjusted OR = 2.79; 95% CI: 1.24-6.29; p = 0.01). The odds of myopia in a child was greater if a smoker smokes at home, in the family car, or in the presence of the child (adjusted OR = 3.95; 95% CI: 1.41-11.09; p < 0.01) compared to non-exposed child. In contrast to myopia, childhood exposure to passive smoke did not systematically shift mean values for SE or AL. In this prospective birth cohort study, we found that childhood exposure to passive smoke from birth to before six months slightly increased the risk of early-onset myopia. This may indicate a delayed response to passive smoke exposure before six months and the development of myopia at three years of age. Our study is limited by the small number of myopic children at this young age. Thus, larger prospective studies using more objective cotinine level measures are required to fully establish and understand the influence of tobacco smoke on refractive development in older children. © 2016 The Authors Ophthalmic & Physiological Optics © 2016 The College of Optometrists.

Comprehensive replication of the relationship between myopia-related genes and refractive errors in a large Japanese cohort.

PubMed

Yoshikawa, Munemitsu; Yamashiro, Kenji; Miyake, Masahiro; Oishi, Maho; Akagi-Kurashige, Yumiko; Kumagai, Kyoko; Nakata, Isao; Nakanishi, Hideo; Oishi, Akio; Gotoh, Norimoto; Yamada, Ryo; Matsuda, Fumihiko; Yoshimura, Nagahisa

2014-10-21

We investigated the association between refractive error in a Japanese population and myopia-related genes identified in two recent large-scale genome-wide association studies. Single-nucleotide polymorphisms (SNPs) in 51 genes that were reported by the Consortium for Refractive Error and Myopia and/or the 23andMe database were genotyped in 3712 healthy Japanese volunteers from the Nagahama Study using HumanHap610K Quad, HumanOmni2.5M, and/or HumanExome Arrays. To evaluate the association between refractive error and recently identified myopia-related genes, we used three approaches to perform quantitative trait locus analyses of mean refractive error in both eyes of the participants: per-SNP, gene-based top-SNP, and gene-based all-SNP analyses. Association plots of successfully replicated genes also were investigated. In our per-SNP analysis, eight myopia gene associations were replicated successfully: GJD2, RASGRF1, BICC1, KCNQ5, CD55, CYP26A1, LRRC4C, and B4GALNT2.Seven additional gene associations were replicated in our gene-based analyses: GRIA4, BMP2, QKI, BMP4, SFRP1, SH3GL2, and EHBP1L1. The signal strength of the reported SNPs and their tagging SNPs increased after considering different linkage disequilibrium patterns across ethnicities. Although two previous studies suggested strong associations between PRSS56, LAMA2, TOX, and RDH5 and myopia, we could not replicate these results. Our results confirmed the significance of the myopia-related genes reported previously and suggested that gene-based replication analyses are more effective than per-SNP analyses. Our comparison with two previous studies suggested that BMP3 SNPs cause myopia primarily in Caucasian populations, while they may exhibit protective effects in Asian populations. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Childhood febrile illness and the risk of myopia in UK Biobank participants

PubMed Central

Guggenheim, J A; Williams, C

2016-01-01

Purpose Historical reports suggest febrile illness during childhood is a risk factor for myopia. The establishment of the UK Biobank provided a unique opportunity to investigate this relationship. Patients and methods We studied a sample of UK Biobank participants of White ethnicity aged 40–69 years old who underwent autorefraction (N=91 592) and were classified as myopic (≤−0.75 Dioptres (D)), highly myopic (≤−6.00 D), or non-myopic (>−0.75 D). Self-reported age at diagnosis of past medical conditions was ascertained during an interview with a nurse at a Biobank assessment centre. Logistic regression analysis was used to calculate the odds ratio (OR) for myopia or high myopia associated with a diagnosis before age 17 years of each of nine febrile illnesses, after adjusting for potential confounders (age, sex, highest educational qualification, and birth order). Results Rubella, mumps, and pertussis were associated with myopia: rubella, OR=1.38, 95% CI: 1.03–1.85, P=0.030; mumps, OR=1.32, 95% CI: 1.07–1.64, P=0.010; and pertussis, OR=1.39, 95% CI 1.03–1.87, P=0.029. Measles, rubella, and pertussis were associated with high myopia: measles, OR=1.48, 95% CI: 1.07–2.07, P=0.019; rubella, OR=1.94, 95% CI: 1.12–3.35, P=0.017; and pertussis, OR=2.15, 95% CI: 1.24–3.71, P=0.006. The evidence did not support an interaction between education and febrile illness in explaining the above risks. Conclusion A history of childhood measles, rubella, or pertussis was associated with high myopia, whereas a history of childhood rubella, mumps, or pertussis was associated with any myopia. The reasons for these associations are unclear. PMID:26846593

Emmetropisation and the aetiology of refractive errors

PubMed Central

Flitcroft, D I

2014-01-01

The distribution of human refractive errors displays features that are not commonly seen in other biological variables. Compared with the more typical Gaussian distribution, adult refraction within a population typically has a negative skew and increased kurtosis (ie is leptokurtotic). This distribution arises from two apparently conflicting tendencies, first, the existence of a mechanism to control eye growth during infancy so as to bring refraction towards emmetropia/low hyperopia (ie emmetropisation) and second, the tendency of many human populations to develop myopia during later childhood and into adulthood. The distribution of refraction therefore changes significantly with age. Analysis of the processes involved in shaping refractive development allows for the creation of a life course model of refractive development. Monte Carlo simulations based on such a model can recreate the variation of refractive distributions seen from birth to adulthood and the impact of increasing myopia prevalence on refractive error distributions in Asia. PMID:24406411

Pharmaceutical intervention for myopia control

PubMed Central

Ganesan, Prema; Wildsoet, Christine F

2010-01-01

Myopia is the result of a mismatch between the optical power and the length of the eye, with the latter being too long. Driving the research in this field is the need to develop myopia treatments that can limit axial elongation. When axial elongation is excessive, as in high myopia, there is an increased risk of visual impairment and blindness due to ensuing pathologies such as retinal detachments. This article covers both clinical studies involving myopic children, and studies involving animal models for myopia. Atropine, a nonselective muscarinic antagonist, has been studied most extensively in both contexts. Because it remains the only drug used in a clinical setting, it is a major focus of the first part of this article, which also covers the many shortcomings of topical ophthalmic atropine. The second part of this article focuses on in vitro and animal-based drug studies, which encompass a range of drug targets including the retina, retinal pigment epithelium and sclera. While the latter studies have contributed to a better understanding of how eye growth is regulated, no new antimyopia drug treatments have reached the clinical setting. Less conservative approaches in research, and in particular, the exploration of new bioengineering approaches for drug delivery, are needed to advance this field. PMID:21258611

Peripheral Defocus and Myopia Progression in Myopic Children Randomly Assigned to Wear Single Vision and Progressive Addition Lenses

PubMed Central

Berntsen, David A.; Barr, Christopher D.; Mutti, Donald O.; Zadnik, Karla

2013-01-01

Purpose. To determine the effect of progressive addition lenses (PALs) and single vision lenses (SVLs) on peripheral defocus in myopic children, and to compare the effect of myopic versus hyperopic peripheral defocus on foveal myopia progression. Methods. Eighty-four myopic children aged 6 to 11 years with spherical equivalent (SE) cycloplegic autorefraction between −0.75 diopters (D) and −4.50 D were randomly assigned to wear SVLs or PALs. Aberrometry measurements of the eye and spectacles were made centrally, 30° nasally, temporally, and superiorly, and 20° inferiorly on the retina using a Complete Ophthalmic Analysis System for Vision Research (COAS-VR). The association between peripheral defocus and the 1-year change in central myopia was investigated. Results. SVLs caused a hyperopic shift in peripheral defocus at all locations (all P ≤ 0.0003). PALs caused a myopic shift in peripheral defocus in three of four locations measured (all P ≤ 0.01) with the greatest shift superiorly due to the PAL addition (−1.04 ± 0.30 D). Superior retinal defocus when wearing either SVLs or PALs was associated with the 1-year change in central myopia. The adjusted 1-year change in central SE myopia was −0.38 D for children with absolute superior myopic defocus (n = 67) and −0.65 D for children with absolute superior hyperopic defocus (n = 17; difference = 0.27 D; P = 0.002). Conclusions. PALs caused a myopic shift in peripheral defocus. Superior myopic defocus was associated with less central myopia progression. These data support the continued investigation of optical designs that result in peripheral myopic defocus as a potential way to slow myopia progression. (ClinicalTrials.gov number, NCT00335049.) PMID:23838771

Posterior corneal curvature changes following Refractive Small Incision Lenticule Extraction.

PubMed

Ganesh, Sri; Patel, Utsav; Brar, Sheetal

2015-01-01

To compare the posterior corneal curvature changes, in terms of corneal power and asphercity, following Refractive Small Incision Lenticule Extraction (ReLEx SMILE) procedure for low, moderate, and high myopia. This retrospective, non randomized, comparative, interventional trial; included 52 eyes of 26 patients, divided in three groups: low myopia (myopia ≤3 D [diopters] spherical equivalent [SE]), moderate myopia (myopia >3 D and <6 D SE), and high myopia (myopia ≥6 D SE). All patients were treated for myopia and myopic astigmatism using ReLEx SMILE. The eyes were examined pre-operatively and 3 months post-operatively using SCHWIND SIRIUS, a three-dimensional rotating Scheimpflug camera with a Placido disc topographer to assess corneal changes with regard to keratometric power and asphericity of the cornea. A statistically significant increase in mean keratometric power in the 3, 5, and 7 mm zones of the posterior corneal surface compared with its pre-ReLEx SMILE value was detected after 3 months in the moderate myopia group (pre-operative [pre-op] -6.14±0.23, post-operative [post-op] -6.29±0.22, P<0.001) and high myopia group (pre-op -6.19±0.16, post-op -6.4±0.18, P<0.001), but there was no significant change in keratometric power of the posterior surface in the low myopia group (pre-op -5.87±0.17, post-op -6.06±0.29, P=0.143). Asphericity (Q-value) of the posterior surface changed significantly (P<0.001) after ReLEx SMILE in the moderate myopia group in the 3, 5, and 7 mm zones, and in the high myopia group in the 3 and 7 mm zones; but there was no significant change in the Q-value in the low myopia group in all three zones (pre-op 0.23±0.43, post-op -0.40±0.71, P=0.170), and in the high myopia group in the 5 mm zone (P=0.228). ReLEx SMILE causes significant changes in posterior corneal keratometric power and asphericity in moderate and high myopia, but the effect is subtle and insignificant in low myopia.

Development and validation of the Alcohol Myopia Scale.

PubMed

Lac, Andrew; Berger, Dale E

2013-09-01

Alcohol myopia theory conceptualizes the ability of alcohol to narrow attention and how this demand on mental resources produces the impairments of self-inflation, relief, and excess. The current research was designed to develop and validate a scale based on this framework. People who were alcohol users rated items representing myopic experiences arising from drinking episodes in the past month. In Study 1 (N = 260), the preliminary 3-factor structure was supported by exploratory factor analysis. In Study 2 (N = 289), the 3-factor structure was substantiated with confirmatory factor analysis, and it was superior in fit to an empirically indefensible 1-factor structure. The final 14-item scale was evaluated with internal consistency reliability, discriminant validity, convergent validity, criterion validity, and incremental validity. The alcohol myopia scale (AMS) illuminates conceptual underpinnings of this theory and yields insights for understanding the tunnel vision that arises from intoxication.

Retinal vascular nonperfusion in siblings with Dandy-Walker variant.

PubMed

Rusu, Irene; Gupta, Mrinali Patel; Patel, Samir N; Oltra, Erica; Chan, R V Paul

2016-04-01

We report the case of a 2-month-old girl with Dandy-Walker variant who presented with strabismus, pathologic myopia measuring -16.00 D in each eye, diffuse chorioretinal atrophy and pigment mottling in the macula of both eyes, and areas of retinal capillary nonperfusion in both eyes. The patient's brother also has Dandy-Walker variant and was found to have bilateral severe myopia, myopic fundi, tilted optic disks with peripapillary atrophy, extensive areas of white without pressure, areas of lattice degeneration, and several chronic-appearing atrophic retinal holes surrounded by pigmentation. We hypothesize that children with Dandy-Walker variant may present with refractive errors such as pathologic myopia and with diverse retinal findings, including retinal ischemia. A lower threshold for ophthalmologic examination may be considered in this population. Copyright © 2016 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

MMP-2 participates in the sclera of guinea pig with form-deprivation myopia via IGF-1/STAT3 pathway.

PubMed

Liu, Y-X; Sun, Y

2018-05-01

To investigate the expression changes of MMP-2 (matrix metalloproteinases-2) mediated by IGF-1 (insulin-like growth factors-1) STAT3 (signal transducer and activator of transcription 3) pathway in the sclera of the form-deprivation myopia guinea pigs. Twenty-four three-week-old guinea pigs were randomly divided into 4 groups: group A (Control), B, C and D. Guinea pigs in group A were sacrificed after 21 days without any special treatment. Guinea pigs in group B were sacrificed 7 days after receiving stitch in the right eye. Guinea pigs in group C were sacrificed 14 days after receiving stitch in the right eye. Guinea pigs in group D were sacrificed 21 days after receiving stitch in the right eye. Eyeball refraction and axial length of guinea pigs were measured before sacrifice. Eyeballs of guinea pigs were enucleated after sacrifice. The expressions of IGF-1, STAT3 and MMP-2 in scleral tissue were detected by Western blot. Axial length extension and myopia appeared in the right eye of guinea pigs in group B. The expressions of IGF-1, STAT3 and MMP-2 in the sclera significantly increased after 7 days of occlusion compared with that in control group A (p<0.05). In the right eye of group C, the axial prolongation and myopia formation appeared after 14-day occlusion. The expressions of IGF-1, STAT3 and MMP-2 in sclera significantly increased compared with that in group A (p<0.05). In the right eye of group D, the axial extension and myopia formation occurred. IGF-1, STAT3 and MMP-2 in scleral significantly upregulated 21 days after occlusion (p<0.05). Furthermore, at different stages of deprivation, protein expressions of MMP-2 and IGF-1 in sclera were positively correlated (r = 0.962, p<0.01). Form-deprivation of guinea pigs lead to increased expressions of IGF-1, STAT3 and MMP-2 in the sclera and myopia of guinea pigs. The expressions of IGF-1, STAT3 and MMP-2 increased progressively over the time of deprivation. Additionally, overexpression of MMP-2 mediated by IGF-1/STAT3 pathway in sclera might promote the formation of myopia.

Predictability and stability of laser-assisted subepithelial keratectomy with mitomycin C for the correction of high myopia.

PubMed

Iu, Lawrence P L; Fan, Michelle C Y; Chen, Ivan N; Lai, Jimmy S M

2017-06-01

The purpose of this study was to evaluate the predictability and stability of laser-assisted subepithelial keratectomy (LASEK) with mitomycin C (MMC) in correction of high myopia (≤-6.0 diopters [D]) as compared to low-to-moderate myopia (>-6.0 D).This is a retrospective, comparative, cohort study which included 43 eyes of 43 consecutive patients who underwent LASEK with MMC in a private hospital in Hong Kong by a single surgeon. Twenty-five eyes had high myopia (mean spherical equivalent [SE] = -8.53 ± 1.82 D) and 18 eyes had low-to-moderate myopia (mean SE = -3.99 ± 1.37 D) before surgery.In terms of refractive predictability, mean SE was significantly better in eyes with preoperative low-to-moderate myopia than high myopia at 6 months (0.04 ± 0.23 vs 0.31 ± 0.52 D, P = .035). In terms of refractive stability, between 1 and 3 months, both groups had mean absolute change of SE of around 0.25 D. Between 3 and 6 months, preoperative low-to-moderate myopia group had significantly less absolute change of SE compared to high myopia group (0.07 vs 0.23 D, P = .003). More eyes with preoperative high myopia changed SE by more than 0.25 D than those with low-to-moderate myopia between 3 and 6 months (32.0% vs 5.6%, P = .057).In conclusion, LASEK with MMC is more unpredictable and unstable in correction of high myopia than low-to-moderate myopia. The refractive outcome of most low-to-moderate myopia correction stabilizes at 3 months. Stability is not achieved until after 6 months in high myopia correction.

Effectiveness of combined macular buckle under direct vision and vitrectomy with ILM peeling in refractory macular hole retinal detachment with extreme high axial myopia: a 24-month comparative study

PubMed Central

Ma, Jin; Li, Honghui; Ding, Xiaohu; Tanumiharjo, Silvia; Lu, Lin

2017-01-01

Purpose To evaluate the efficacy of a combined macular buckle under direct vision and 23-gauge pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling in refractory macular hole retinal detachment (MHRD) with extreme high axial myopia. Design Prospective, randomised controlled study. Participants The study included 98 eyes of 98 patients of MHRD with extreme high axial (>30 mm) myopia. Intervention Patients were randomly assigned to undergo PPV with ILM peeling (group 1, n=52) or PPV with ILM peeling combined with macular buckle under direct vision (group 2, n=46). Main outcome measures Complete ocular examination included best-corrected visual acuity (BCVA) (LogMAR), applanation tonometry, optical biometry, slit-lamp biomicroscopy, colour fundus photography, ultrasound examination and optical coherence tomography at baseline and every follow-up visit. Results Initial retinal reattachment rate was significantly higher in group 2 than in group 1 at 12-month postoperatively (χ2 test, p=0.020). Macular hole closure rate in group 2 was significantly higher than that in group 1 at 3, 12, 18 and 24 months postoperatively (Fisher's exact test, p<0.05). In initial retinal reattachment cases, the mean BCVA decreased significantly in group 2 than in group 1 at 3 months postoperatively (Wilcoxon matched pairs signed rank test, p=0.036), and had increased significantly in group 2 than in group 1 since 6 months postoperatively (Wilcoxon matched pairs signed rank test, p<0.05). Mean axial lengths in group 2 were significantly shorter than that of group 1 at each follow-up time point (Wilcoxon matched pairs signed rank test, p<0.05). Conclusions Combined macular buckle under direct vision and PPV with ILM peeling is more effective in treatment of MHRD with extreme high axial (>30 mm) myopia. PMID:28292775

Association between Refractive Errors and Ocular Biometry in Iranian Adults

PubMed Central

Hashemi, Hassan; Khabazkhoob, Mehdi; Emamian, Mohammad Hassan; Shariati, Mohammad; Miraftab, Mohammad; Yekta, Abbasali; Ostadimoghaddam, Hadi; Fotouhi, Akbar

2015-01-01

Purpose: To investigate the association between ocular biometrics such as axial length (AL), anterior chamber depth (ACD), lens thickness (LT), vitreous chamber depth (VCD) and corneal power (CP) with different refractive errors. Methods: In a cross-sectional study on the 40 to 64-year-old population of Shahroud, random cluster sampling was performed. Ocular biometrics were measured using the Allegro Biograph (WaveLight AG, Erlangen, Germany) for all participants. Refractive errors were determined using cycloplegic refraction. Results: In the first model, the strongest correlations were found between spherical equivalent with axial length and corneal power. Spherical equivalent was strongly correlated with axial length in high myopic and high hyperopic cases, and with corneal power in high hyperopic cases; 69.5% of variability in spherical equivalent was attributed to changes in these variables. In the second model, the correlations between vitreous chamber depth and corneal power with spherical equivalent were stronger in myopes than hyperopes, while the correlations between lens thickness and anterior chamber depth with spherical equivalent were stronger in hyperopic cases than myopic ones. In the third model, anterior chamber depth + lens thickness correlated with spherical equivalent only in moderate and severe cases of hyperopia, and this index was not correlated with spherical equivalent in moderate to severe myopia. Conclusion: In individuals aged 40-64 years, corneal power and axial length make the greatest contribution to spherical equivalent in high hyperopia and high myopia. Anterior segment biometric components have a more important role in hyperopia than myopia. PMID:26730304

[Analysis of the influence factors of school-age children's refractive status].

PubMed

Chen, Z G; Chen, M C; Zhang, J Y; Cai, D Q; Wang, Q; Lin, S S; Chen, J W; Zhong, H L

2016-11-11

Objective: To analyze the influence of the eye biological parameters, height, and weight on the school-age children's refractive status. Methods: Cross-sectional study. A total of 1 656 children (1 656 eyes), aged from 7 to 14 years, were selected from 8 schools in Wenzhou during June 2012 and June 2013. The height and weight of each child were measured, and the body mass index (BMI) was calculated. The eye biological parameters, including axial length (AL), corneal power (C=1/CR), anterior chamber depth (ACD), and white to white (WTW), were measured by IOLMaster (version 5.0, Carl Zeiss, Germany), and the AL/CR was calculated. Refraction was measured by fast cycloplegic retinoscopy, and the spherical equivalent (SE) was calculated. Only right eyes were included in the analysis. SPSS16.0 was used to analyze the data. The correlations of the equivalent spherical power, the eye biological parameters, height, weight, and BMI were evaluated. Linear regression analysis was used for the SE, AL, and AL/CR. Results: The prevalence of myopia in 7- to 14-year-old school-age children was 50.2% on the average, 48.4% in boys, and 51.7% in girls. The average SE was (-1.07±1.74) D. With adjustment of the age, gender, urban and rural areas, there was an association between the SE and AL, AL/CR, ACD, height and weight. The correlation coefficient was -0.663, -0.730, -0.416, -0.365, and -0.281, respectively ( P< 0.05). There was no significant correlation between the SE and WTW, corneal power and BMI. Regarding the different refractive statuses, there was a stronger correlation between the SE and AL, AL/CR in children with hyperopia, moderate myopia or high myopia than those with emmetropia or mild myopia ( P< 0.01). In the older children, the correlation between the SE and AL, AL/CR was stronger. Linear regression analysis showed SE= 26.55-9.11·AL/CR and 23.0-1.02·AL. Conclusions: There was an association between the SE and AL, AL/CR, ACD, height and weight in school-age children. In children with hyperopia, moderate myopia, high myopia or at an older age, the correlation was more significant between the SE and AL, AL/CR. (Chin J Ophthalmol, 2016, 52:831-835) .

Posterior corneal curvature changes following Refractive Small Incision Lenticule Extraction

PubMed Central

Ganesh, Sri; Patel, Utsav; Brar, Sheetal

2015-01-01

Purpose To compare the posterior corneal curvature changes, in terms of corneal power and asphercity, following Refractive Small Incision Lenticule Extraction (ReLEx SMILE) procedure for low, moderate, and high myopia. Methods This retrospective, non randomized, comparative, interventional trial; included 52 eyes of 26 patients, divided in three groups: low myopia (myopia ≤3 D [diopters] spherical equivalent [SE]), moderate myopia (myopia >3 D and <6 D SE), and high myopia (myopia ≥6 D SE). All patients were treated for myopia and myopic astigmatism using ReLEx SMILE. The eyes were examined pre-operatively and 3 months post-operatively using SCHWIND SIRIUS, a three-dimensional rotating Scheimpflug camera with a Placido disc topographer to assess corneal changes with regard to keratometric power and asphericity of the cornea. Results A statistically significant increase in mean keratometric power in the 3, 5, and 7 mm zones of the posterior corneal surface compared with its pre-ReLEx SMILE value was detected after 3 months in the moderate myopia group (pre-operative [pre-op] −6.14±0.23, post-operative [post-op] −6.29±0.22, P<0.001) and high myopia group (pre-op −6.19±0.16, post-op −6.4±0.18, P<0.001), but there was no significant change in keratometric power of the posterior surface in the low myopia group (pre-op −5.87±0.17, post-op −6.06±0.29, P=0.143). Asphericity (Q-value) of the posterior surface changed significantly (P<0.001) after ReLEx SMILE in the moderate myopia group in the 3, 5, and 7 mm zones, and in the high myopia group in the 3 and 7 mm zones; but there was no significant change in the Q-value in the low myopia group in all three zones (pre-op 0.23±0.43, post-op −0.40±0.71, P=0.170), and in the high myopia group in the 5 mm zone (P=0.228). Conclusion ReLEx SMILE causes significant changes in posterior corneal keratometric power and asphericity in moderate and high myopia, but the effect is subtle and insignificant in low myopia. PMID:26229428

Ten years after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) for moderate to high myopia (control-matched study).

PubMed

Alió, J L; Ortiz, D; Muftuoglu, O; Garcia, M J

2009-10-01

To compare the long-term outcomes of photorefractive keratectomy (PRK) and laser in situ keratomilesis (LASIK) for myopia between -6 and -10 D. A retrospective, control-matched study including 68 eyes, 34 which underwent PRK and 34 LASIK, with myopia between -6 and -10 D, operated using the VISX 20/20 excimer laser, was performed. Optical zones of 5.5 to 6 mm were used. All PRK-treated eyes were matched with LASIK-treated eyes of the same age, spherical equivalent within +/-1.25 D, sphere within +/-1.5 D and cylinder within +/-2.5 D. All patients were evaluated 3 months, 1 year, 2 years, 5 years and 10 years after surgery. The main outcomes measures were refractive predictability and stability, safety, efficacy and re-treatment rate. At 10 years, 20 (71%) and 23 (88%) were within +/-1.00 D after PRK and LASIK respectively. The re-treatment rate was 35% and 18% respectively. No eye lost more than two lines of BSCVA in both groups. The efficacy was 0.90 for PRK and 0.95 for LASIK. Both PRK and LASIK were safe for moderate myopia. LASIK demonstrated slightly better efficacy, predictability, and less rate of re-treatment after 10 years. The technical improvements should be taken into account when comparing these results with those obtained more recently.

[Prevalence of myopia and increase trend in children and adolescents aged 7-18 years in Han ethnic group in China, 2005-2014].

PubMed

Dong, Y H; Liu, H B; Wang, Z H; Yang, Z P; Xu, R B; Yang, Z G; Ma, J

2017-05-10

Objective: To understand and evaluate the prevalence of myopia and its trend in children and adolescents aged 7-18 years in Han ethnic group in China from 2005 to 2014, and provide evidence for the prevention of myopia. Methods: The data of 2005, 2010 and 2014 Chinese National Students Constitution and Health Surveys were collected. The children and adolescents with complete detection data of binoculus were selected as study subjects. The sample size of three studies were 233 108, 215 319 and 212 743, respectively. The method of curve fitting was used to simulate the myopia detection increase model and analyze the gender and area specific myopia detection increase trends and characteristics from 2005 to 2014. Results: The overall myopia detection rate increased gradually in the children and adolescents aged 7 to 18, which was 47.5 % in 2005, 55.5 % in 2010 and 57.1 % in 2014, respectively. The increase slowed in 2014. A"parabola" shape of myopia detection increase rate was observed. Myopia detection rate increased with age before puberty and decreased with age after puberty gradually. A"cross phenomenon" of myopia detection increase was observed in boys and girls between urban and rural areas. The increase of myopia detection was mainly in urban students before puberty and in rural students after puberty. The age of myopia prevalence peak has become earlier constantly in children and adolescents aged 7-18 years from 2005 to 2014, which was 13 years old in 2005, 12 years old in 2010 and 11 years old in 2014. The increase rate was about 7 % . During 2005-2014, the increase rate of myopia detection gradually increased in younger students and tended to zero in older students. Conclusion: The detection rate of myopia was still high in children and adolescents in China. The age of myopia prevalence peak has become earlier gradually.

Updates of pathologic myopia.

PubMed

Ohno-Matsui, Kyoko; Lai, Timothy Y Y; Lai, Chi-Chun; Cheung, Chiu Ming Gemmy

2016-05-01

Complications from pathologic myopia are a major cause of visual impairment and blindness, especially in east Asia. The eyes with pathologic myopia may develop loss of the best-corrected vision due to various pathologies in the macula, peripheral retina and the optic nerve. Despite its importance, the definition of pathologic myopia has been inconsistent. The refractive error or axial length alone often does not adequately reflect the 'pathologic myopia'. Posterior staphyloma, which is a hallmark lesion of pathologic myopia, can occur also in non-highly myopic eyes. Recently a revised classification system for myopic maculopathy has been proposed to standardize the definition among epidemiological studies. In this META-PM (meta analyses of pathologic myopia) study classification, pathologic myopia was defined as the eyes having chorioretinal atrophy equal to or more severe than diffuse atrophy. In addition, the advent of new imaging technologies such as optical coherence tomography (OCT) and three dimensional magnetic resonance imaging (3D MRI) has enabled the detailed observation of various pathologies specific to pathologic myopia. New therapeutic approaches including intravitreal injections of anti-vascular endothelial growth factor agents and the advance of vitreoretinal surgeries have greatly improved the prognosis of patients with pathologic myopia. The purpose of this review article is to provide an update on topics related to the field of pathologic myopia, and to outline the remaining issues which need to be solved in the future. Copyright © 2016 Elsevier Ltd. All rights reserved.

A review of environmental risk factors for myopia during early life, childhood and adolescence.

PubMed

Ramamurthy, Dharani; Lin Chua, Sharon Yu; Saw, Seang-Mei

2015-11-01

Myopia is a significant public health problem worldwide, particularly in East Asian countries. The increasing prevalence of myopia poses a huge socio-economic burden and progressive high myopia can lead to sight-threatening ocular complications. Hence, the prevention of early-onset myopia progressing to pathological high myopia is important. Recent epidemiological studies suggest that increased outdoor time is an important modifiable environmental factor that protects young children from myopia. This protective effect may be due to high light intensity outdoors, the chromaticity of daylight or increased vitamin D levels. This review summarises the possible underlying biological mechanisms for the protective association between time outdoors and myopia, including the potential role of nicotinic acetylcholine receptors in refractive error development. Recent evidence for the role of other environmental risk factors such as near work, birth seasons, parental smoking and birth order are also summarised. © 2015 Optometry Australia.

Childhood myopia and parental smoking.

PubMed

Saw, S-M; Chia, K-S; Lindstrom, J M; Tan, D T H; Stone, R A

2004-07-01

To examine the relation between exposure to passive parental smoke and myopia in Chinese children in Singapore. 1334 Chinese children from three schools in Singapore were recruited, all of whom were participants in the Singapore Cohort study Of the Risk factors for Myopia (SCORM). Information on whether the father or mother smoked, number of years smoked, and the number of cigarettes smoked per day during the child's lifetime were derived. These data were correlated with contemporaneously obtained data available in SCORM. The children's cycloplegic autorefraction, corneal curvature radius, and biometry measures were compared with reported parental smoking history. There were 434 fathers (33.3%) and 23 mothers (1.7%) who smoked during their child's lifetime. There were no significant trends observed between paternal smoking and refractive error or axial length. After controlling for age, sex, school, mother's education, and mother's myopia, children with mothers who had ever smoked during their lifetime had more "positive" refractions (adjusted mean -0.28 D v -1.38 D) compared with children whose mother did not smoke (p = 0.012). The study found no consistent evidence of association between parental smoking and refractive error. There was a suggestion that children whose mothers smoked cigarettes had more hyperopic refractions, but the absence of a relation with paternal smoking and the small number of mothers who smoked in this sample preclude definite conclusions about a link between passive smoking exposure and myopia.

Prevalence of refractive errors and associated risk factors in subjects with type 2 diabetes mellitus SN-DREAMS, report 18.

PubMed

Rani, Padmaja Kumari; Raman, Rajiv; Rachapalli, Sudhir R; Kulothungan, Vaitheeswaran; Kumaramanickavel, Govindasamy; Sharma, Tarun

2010-06-01

To report the prevalence of refractive errors and the associated risk factors in subjects with type 2 diabetes mellitus from an urban Indian population. Population-based, cross-sectional study. One thousand eighty participants selected from a pool of 1414 subjects with diabetes. A population-based sample of 1414 persons (age >40 years) with diabetes (identified as per the World Health Organization criteria) underwent a comprehensive eye examination, including objective and subjective refractions. One thousand eighty subjects who were phakic in the right eye with best corrected visual acuity of > or =20/40 were included in the analysis for prevalence of refractive errors. Univariate and multivariate analyses were done to find out the independent risk factors associated with the refractive errors. The mean refraction was +0.20+/-1.72, and the Median, +0.25 diopters. The prevalence of emmetropia (spherical equivalent [SE], -0.50 to +0.50 diopter sphere [DS]) was 39.26%. The prevalence of myopia (SE <-0.50 DS), high myopia (SE <-5.00 DS), hyperopia (SE >+0.50 DS), and astigmatism (SE <-0.50 cyl) was 19.4%, 1.6%, 39.7%, and 47.4%, respectively. The advancing age was an important risk factor for the three refractive errors: for myopia, odds ratio (OR; 95% confidence interval [CI] 4.06 [1.74-9.50]; for hyperopia, OR [95% CI] 5.85 [2.56-13.39]; and for astigmatism, OR [95% CI] 2.51 [1.34-4.71]). Poor glycemic control was associated with myopia (OR [95% CI] 4.15 [1.44-11.92]) and astigmatism (OR [95% CI] 2.01 [1.04-3.88]). Female gender was associated with hyperopia alone) OR [95% CI] 2.00 [1.42-2.82]. The present population-based study from urban India noted a high prevalence of refractive errors (60%) among diabetic subjects >40 years old; the prevalence of astigmatism (47%) was higher than hyperopia (40%) or myopia (20%). Copyright 2010 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Prevalence and risk factors for myopia in second-grade primary school children in Taipei: A population-based study.

PubMed

Hsu, Chih-Chien; Huang, Nicole; Lin, Pei-Yu; Tsai, Der-Chong; Tsai, Ching-Yao; Woung, Lin-Chung; Liu, Catherine Jui-Ling

2016-11-01

High myopia is associated with multiple ocular morbidities that may lead to irreversible blindness. Because high myopia in an adult is thought to be related to onset of myopia in very early childhood, detecting myopia early and working to improve modifiable risk factors may help reduce the development of high myopia. In this study, we tried to evaluate the prevalence of myopia and associated risk factors in second-grade primary school children in Taipei, Taiwan. A questionnaire was distributed to the participants' parents, and their written informed consent was obtained before performing eye examinations that included visual acuity testing and cycloplegic autorefraction. Multiple logistic regression models were applied to assess possible risk factors associated with myopia. Myopia was defined as spherical equivalent of -0.50 D or less in either eye. The prevalence of myopia in the second graders was 36.4%. After adjustment for other characteristics, the following variables were significantly associated with a higher risk of myopia: male sex [odds ratio (OR)=1.24, p<0.001]; suburban residence (vs. urban; OR=1.10, p=0.02); lower maternal education level (OR=1.25, p<0.001); the presence of myopia in one parent (OR=1.66, p<0.001) or both parents (OR=2.82, p<0.001); time spent on near-work activity every day (OR=1.21, p<0.001); shorter visual distance when doing near-work activity (OR=1.17, p<0.001); and participation in an after-school tutorial program (OR=1.20, p<0.001). By contrast, resting after 30 minutes of near-work activity (OR=0.84, p<0.001) and spending more time participating in outdoor activities on weekends (OR=0.91, p=0.03) were significantly associated with a lower risk of myopia. Our findings indicate that lifestyle and reading habits impact the development of myopia during early childhood. Behavior modification, such as more time spent outside during the day and limited near-work activity, may be a feasible strategy for curbing the increasingly high prevalence of myopia in Taipei. Copyright © 2016. Published by Elsevier Taiwan LLC.

Challenges In Early Glaucoma Detection.

PubMed

Dervisevic, Edita; Pavljasevic, Suzana; Dervisevic, Almir; Kasumovic, Sanja Sefic

2016-06-01

Glaucoma is the most common optic neuropathy which is characterized by progressive loss of retinal ganglion cells, the excavation of the optic nerve head, associated with defects in the visual field. It is not a disease, but the final result of united and yet completely unidentified cellular and subcellular processes and effects of many factors responsible for changes in retinal ganglion cells leading to their accelerated apoptosis. This is a prospective-retrospective, comparative, randomized clinical trial that included 150 patients, 97 were female and 53 male. The age of patients ranged from 18 to 80 years. The highest degree of myopia in category of tilted optic discs had patients with large disc (4.05 + -0.65). Values of the degree of myopia have linearly declined in relation to the size of the oblique disc. The analysis of the results revealed that the subjects who had a higher degree of myopia associated with glaucoma had frequent parapapillar atrophy of alpha and beta zones. The highest percentage of subjects with parapapillar changes were in the group of patients who had other than glaucoma and myopia (62%), then in the group of patients with glaucoma only (56%). Previous studies on the relationship between myopia and open-angle glaucoma are based on the results of observational studies. However, according to recent findings, based on the available studies, the systematic approach to estimate the association between myopia and glaucoma does not exist. Disc Damage Likelihood Scale (DDLS) is a new system for assessing glaucomatous damage of the optic disc which strongly correlates with the degree of visual field loss.

Automatic classification of pathological myopia in retinal fundus images using PAMELA

NASA Astrophysics Data System (ADS)

Liu, Jiang; Wong, Damon W. K.; Tan, Ngan Meng; Zhang, Zhuo; Lu, Shijian; Lim, Joo Hwee; Li, Huiqi; Saw, Seang Mei; Tong, Louis; Wong, Tien Yin

2010-03-01

Pathological myopia is the seventh leading cause of blindness. We introduce a framework based on PAMELA (PAthological Myopia dEtection through peripapilLary Atrophy) for the detection of pathological myopia from fundus images. The framework consists of a pre-processing stage which extracts a region of interest centered on the optic disc. Subsequently, three analysis modules focus on detecting specific visual indicators. The optic disc tilt ratio module gives a measure of the axial elongation of the eye through inference from the deformation of the optic disc. In the texturebased ROI assessment module, contextual knowledge is used to demarcate the ROI into four distinct, clinically-relevant zones in which information from an entropy transform of the ROI is analyzed and metrics generated. In particular, the preferential appearance of peripapillary atrophy (PPA) in the temporal zone compared to the nasal zone is utilized by calculating ratios of the metrics. The PPA detection module obtains an outer boundary through a level-set method, and subtracts this region against the optic disc boundary. Temporal and nasal zones are obtained from the remnants to generate associated hue and color values. The outputs of the three modules are used as in a SVM model to determine the presence of pathological myopia in a retinal fundus image. Using images from the Singapore Eye Research Institute, the proposed framework reported an optimized accuracy of 90% and a sensitivity and specificity of 0.85 and 0.95 respectively, indicating promise for the use of the proposed system as a screening tool for pathological myopia.

Near work, outdoor activity, and myopia in children in rural China: the Handan offspring myopia study.

PubMed

Lin, Zhong; Gao, Tie Ying; Vasudevan, Balamurali; Ciuffreda, Kenneth J; Liang, Yuan Bo; Jhanji, Vishal; Fan, Su Jie; Han, Wei; Wang, Ning Li

2017-11-17

The near work and outdoor activity are the most important environmental risk factors for myopia. However, data from Chinese rural children are relatively rare and remain controversial. Therefore, the purpose of this study was to evaluate the relationship of both near work and outdoor activities with refractive error in rural children in China. In this cross-sectional study, 572 (65.1%) of 878 children (6-18 years of age) were included from the Handan Offspring Myopia Study (HOMS). Information from the parents on these children, as well as the parent's non-cycloplegic refraction, were obtained from the database of the Handan Eye Study conducted in the years 2006-2007. A comprehensive vision examination, including cycloplegic refraction, and a related questionnaire, were assessed on all children. The overall time spent on near work and outdoor activity in the children was 4.8 ± 1.6 and 2.9 ± 1.4 h per day, respectively. Myopic children spent more time on near work (5.0 ± 1.7 h vs.4.7 ± 1.6 h, p = 0.049), while no significant difference was found in outdoor activity hours (2.8 ± 1.3 h vs. 3.0 ± 1.4 h, p = 0.38), as compared to non-myopic children. In the multiple logistic analysis, in general, no association between near work and myopia was found after adjusting for the children's age, gender, parental refractive error, parental educational level, and daily outdoor activity hours [odds ratio (OR), 95% confidence interval (CI): 1.10, 0.94-1.27]. However, a weak protective effect of the outdoor activity on myopia was found (OR, 95% CI: 0.82, 0.70-0.96), after adjusting for similar confounders. In general, no association between near work and myopia was found, except for the high near work subgroup with moderate outdoor activity levels. A weak protective effect of outdoor activity on myopia in Chinese rural children was observed.

Myopia-The future progression of myopia: Seeing where we are going.

PubMed

Mackey, David A

2016-12-01

The Marshall Parks Lecture 2015, entitled "Myopia-The future progression of myopia: Seeing where we are going," was presented by Professor David A. Mackey at the American Academy of Ophthalmology meeting held in Las Vegas in November 2015.

The effect of intravitreal injection of vehicle solutions on form deprivation myopia in tree shrews.

PubMed

Ward, Alexander H; Siegwart, John T; Frost, Michael R; Norton, Thomas T

2016-04-01

lntravitreal injection of substances dissolved in a vehicle solution is a common tool used to assess retinal function. We examined the effect of injection procedures (three groups) and vehicle solutions (four groups) on the development of form deprivation myopia (FDM) in juvenile tree shrews, mammals closely related to primates, starting at 24 days of visual experience (about 45 days of age). In seven groups (n = 7 per group), the myopia produced by monocular form deprivation (FD) was measured daily for 12 days during an 11-day treatment period. The FD eye was randomly selected; the contralateral eye served as an untreated control. The refractive state of both eyes was measured daily, starting just before FD began (day 1); axial component dimensions were measured on day 1 and after eleven days of treatment (day 12). Procedure groups: the myopia (treated eye - control eye refraction) in the FD group was the reference. The sham group only underwent brief daily anesthesia and opening of the conjunctiva to expose the sclera. The puncture group, in addition, had a pipette inserted daily into the vitreous. In four vehicle groups, 5 μL of vehicle was injected daily. The NaCl group received 0.85% NaCl. In the NaCl + ascorbic acid group, 1 mg/mL of ascorbic acid was added. The water group received sterile water. The water + ascorbic acid group received water with ascorbic acid (1 mg/mL). We found that the procedures associated with intravitreal injections (anesthesia, opening of the conjunctiva, and puncture of the sclera) did not significantly affect the development of FDM. However, injecting 5 μL of any of the four vehicle solutions slowed the development of FDM. NaCl had a small effect; myopia development in the last 6 days (-0.15 ± 0.08 D/day) was significantly less than in the FD group (-0.55 ± 0.06 D/day). NaCl + Ascorbic acid further slowed the development of FDM on several treatment days. H2O (-0.09 ± 0.05 D/day) and H2O + ascorbic acid (-0.08 ± 0.05 D/day) both almost completely blocked myopia development. The treated eye vitreous chamber elongation, compared with the control eye, in all groups was consistent with the amount of myopia. When FD continued (days 12-16) without injections in the water and water + ascorbic acid groups, the rate of myopia development quickly increased. Thus, it appears the vehicles affected retinal signaling rather than causing damage. The effect of water and water + ascorbic acid may be due to reduced osmolality or ionic concentration near the tip of the injection pipette. The effect of ascorbic acid, compared to NaCl alone, may be due to its reported dopaminergic activity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Concise Review: Using Stem Cells to Prevent the Progression of Myopia – A Concept

PubMed Central

Janowski, Miroslaw; Bulte, Jeff W.M.; Handa, James T.; Rini, David; Walczak, Piotr

2016-01-01

The prevalence of myopia has increased in modern society due to the educational load of children. This condition is growing rapidly, especially in Asian countries where it has already reached a pandemic level. Typically, the younger the child’s age at the onset of myopia, the more rapidly the condition will progress and the greater the likelihood that it will develop the known sight-threatening complications of high myopia. This rise in incidence of severe myopia has contributed to an increased frequency of eye diseases in adulthood, which often complicate therapeutic procedures. Currently, no treatment is available to prevent myopia progression. Stem cell therapy can potentially address two components of myopia. Regardless of the exact etiology, myopia is always associated with scleral weakness. In this context, a strategy aimed at scleral reinforcement by transplanting connective tissue-supportive mesenchymal stem cells (MSCs) is an attractive approach that could yield effective and universal therapy. Sunlight exposure appears to have a protective effect against myopia. It is postulated that this effect is mediated via local ocular production of dopamine. With a variety of dopamine-producing cells already available for the treatment of Parkinson’s disease, stem cells engineered for dopamine production could be utilized for the treatment of myopia. In this review, we further explore these concepts and present evidence from the literature to support the use of stem cell therapy for the treatment of myopia. PMID:25752937

Axial Myopia Is Associated with Visual Field Prognosis of Primary Open-Angle Glaucoma

PubMed Central

Qiu, Chen; Qian, Shaohong; Sun, Xinghuai; Zhou, Chuandi; Meng, Fanrong

2015-01-01

Purpose To identify whether myopia was associated with the visual field (VF) progression of primary open-angle glaucoma (POAG). Methods A total of 270 eyes of 270 POAG followed up for more than 3 years with ≥9 reliable VFs by Octopus perimetry were retrospectively reviewed. Myopia was divided into: mild myopia (-2.99 diopter [D], 0), moderate myopia (-5.99, 3.00 D), marked myopia (-9.00, -6.00 D) and non-myopia (0 D or more). An annual change in the mean defect (MD) slope >0.22 dB/y and 0.30 dB/y was defined as fast progression, respectively. Logistic regression was performed to determine prognostic factors for VF progression. Results For the cutoff threshold at 0.22 dB/y, logistic regression showed that vertical cup-to-disk ratio (VCDR; p = 0.004) and the extent of myopia (p = 0.002) were statistically significant. When logistic regression was repeated after excluding the extent of myopia, axial length (AL; p = 0.008, odds ratio [OR] = 0.796) reached significance, as did VCDR (p = 0.001). Compared to eyes with AL≤23 mm, the OR values were 0.334 (p = 0.059), 0.309 (p = 0.044), 0.266 (p = 0.019), 0.260 (p = 0.018), respectively, for 23 26 mm. The significance of vertical cup-to-disk ratio of (p = 0.004) and the extent of myopia (p = 0.008) did not change for the cutoff threshold at 0.30dB/y. Conclusions VCDR and myopia were associated with VF prognosis of POAG. Axial myopia may be a protective factor against VF progression. PMID:26214313

Refractive Errors and Academic Achievements of Primary School Children.

PubMed

Joseph, Lucyamma

2014-01-01

The current study was conducted among school children of selected schools of Thiruvananthapuram district of Kerala. It was designed to investigate the effect of refractive errors on academic achievement of primary school children. Experimental method was used in the study and the study used a sample of 185 children. An equated sample without myopia were selected as control group. Academic achievement tests based on the study syllabus were prepared and administered to both groups. The children with myopia were given corrective devices such as glasses prescribed by the ophthalmologist. After five months academic achievement tests were again given to both groups and the results of the scores between two groups as well as the scores before and after correction of errors were compared, which showed a significant influence of myopia on academic achievement and examination anxiety of children.

Occupational lifting and rhegmatogenous retinal detachment: a follow-up study of Swedish conscripts.

PubMed

Farioli, Andrea; Kriebel, David; Mattioli, Stefano; Kjellberg, Katarina; Hemmingsson, Tomas

2017-07-01

To investigate the association between occupational lifting and the risk of rhegmatogenous retinal detachment (RRD) using data from a large population of men. We used data from a national cohort of 49 321 Swedish men conscripted for compulsory military service in 1969-1970. We collected information on surgically treated RRD from the National Patient Register and we followed up the cohort between 1991 and 2009 at ages 40-60 years. Exposure to occupational lifting was assessed by applying a job exposure matrix to occupational data from the 1990 census. Incidence rate ratios (IRRs) and 95% CIs were estimated through Poisson regression models adjusted by degree of myopia, income and education level. We observed 217 cases of RRD in 7 80 166 person-years. In univariate analyses we did not observe an association between occupational lifting and RRD. However, after adjustment for myopia and socioeconomic factors, we found an increased risk of RRD (IRR 2.38, 95% CI 1.15 to 4.93) for subjects in the highest category of exposure compared with those in the lowest one. The incidence rate of RRD among subjects lifting heavy loads at least twice per week, aged between 50 years and 59 years, and affected by severe myopia was as high as 7.9 cases per 1000 person-years, compared with an overall rate of 0.28. Our study supports the hypothesis that heavy occupational lifting is a risk factor for RRD. Information on myopia degree and socioeconomic status is necessary when studying the association between occupational lifting and RRD. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

[Character of refractive errors in population study performed by the Area Military Medical Commission in Lodz].

PubMed

Nowak, Michał S; Goś, Roman; Smigielski, Janusz

2008-01-01

To determine the prevalence of refractive errors in population. A retrospective review of medical examinations for entry to the military service from The Area Military Medical Commission in Lodz. Ophthalmic examinations were performed. We used statistic analysis to review the results. Statistic analysis revealed that refractive errors occurred in 21.68% of the population. The most commen refractive error was myopia. 1) The most commen ocular diseases are refractive errors, especially myopia (21.68% in total). 2) Refractive surgery and contact lenses should be allowed as the possible correction of refractive errors for military service.

A microarray analysis of retinal transcripts that are controlled by image contrast in mice.

PubMed

Brand, Christine; Schaeffel, Frank; Feldkaemper, Marita Pauline

2007-06-18

The development of myopia is controlled by still largely unknown retinal signals. The aim of this study was to investigate the changes in retinal mRNA expression after different periods of visual deprivation in mice, while controlling for retinal illuminance. Each group consisted of three male C57BL/6 mice. Treatment periods were 30 min, 4 h, and 6+6 h. High spatial frequencies were filtered from the retinal image by frosted diffusers over one eye while the fellow eyes were covered by clear neutral density (ND) filters that exhibited similar light attenuating properties (0.1 log units) as the diffusers. For the final 30 min of the respective treatment period mice were individually placed in a clear Perspex cylinder that was positioned in the center of a rotating (60 degrees) large drum. The inside of the drum was covered with a 0.1 cyc/degree vertical square wave grating. This visual environment was chosen to standardize illuminances and contrasts seen by the mice. Labeled cRNA was prepared and hybridized to Affymetrix GeneChip Mouse Genome 430 2.0 arrays. Alterations in mRNA expression levels of candidate genes with potential biological relevance were confirmed by semi-quantitative real-time reverse transcription polymerase chain reaction (RT-PCR). In all groups, Egr-1 mRNA expression was reduced in diffuser-treated eyes. Furthermore, the degradation of the spatial frequency spectrum also changed the cFos mRNA level, with reduced expression after 4 h of diffuser treatment. Other interesting candidates were Akt2, which was up-regulated after 30 min of deprivation and Mapk8ip3, a neuron specific JNK binding and scaffolding protein that was temporally regulated in the diffuser-treated eyes only. The microarray analysis demonstrated a pattern of differential transcriptional changes, even though differences in the retinal images were restricted to spatial features. The candidate genes may provide further insight into the biochemical short-term changes following retinal image degradation in mice. Because deprivation of spatial vision leads to increased eye growth and myopia in both animals and humans, it is believed some of the identified genes play a role in myopia development.

Increased preference of surface ablation over laser in situ keratomileusis between 2008–2011 is correlated to risk of ecatasia

PubMed Central

Moisseiev, Elad; Sela, Tzahi; Minkev, Liza; Varssano, David

2013-01-01

Purpose To evaluate the trends in corneal refractive procedure selection for the correction of myopia, focusing on the relative proportions of laser in situ keratomileusis (LASIK) and surface ablation procedures. Methods Only eyes that underwent LASIK or surface ablation for the correction of myopia between 2008–2011 were included in this retrospective study. Additional recorded parameters included patient age, preoperative manifest refraction, corneal thickness, and calculated residual corneal bed thickness. A risk score was given to each eye, based on these parameters, according to the Ectasia Risk Factor Score System (ERFSS), without the preoperative corneal topography. Results This study included 16,163 eyes, of which 38.4% underwent LASIK and 61.6% underwent surface ablation. The risk score correlated with procedure selection, with LASIK being preferred in eyes with a score of 0 and surface ablation in eyes with a score of 2 or higher. When controlling for age, preoperative manifest refraction, corneal thickness, and all parameters, the relative proportion of surface ablation compared with LASIK was found to have grown significantly during the study period. Conclusions Our results indicate that with time, surface ablation tended to be performed more often than LASIK for the correction of myopia in our cohort. Increased awareness of risk factors and preoperative risk assessment tools, such as the ERFSS, have shifted the current practice of refractive surgery from LASIK towards surface ablation despite the former’s advantages, especially in cases in which the risk for ectasia is more than minimal (risk score 2 and higher). PMID:23345963

Vision in former very low birthweight young adults with and without retinopathy of prematurity compared with term born controls: the NZ 1986 VLBW follow-up study.

PubMed

Darlow, Brian A; Elder, Mark J; Kimber, Bridget; Martin, Julia; Horwood, L John

2017-12-06

There are few data on visual outcomes in adulthood of former very low birthweight (VLBW; <1500 g) infants. We aimed to assess vision at 27-29 years in a national cohort of VLBW infants born in 1986 and assessed for retinopathy of prematurity (ROP) when no treatment was available, compared with term born controls. The cohort and controls attended a 2-day assessment in Christchurch as part of a larger study. Visual assessment included glasses prescription measured by focimeter, logarithm of the minimum angle of resolution (logMAR) distance visual acuity (VA), contrast sensitivity, autorefraction, retinal photographs and a questionnaire on vision-related everyday activities. Rates of reduced VA and myopia in the VLBW cohort at 27-29 were compared with the results of vision testing at 7-8 years. 250 VLBW adults (77% those alive) gave study consent and 229 (45 with a history of ROP) were assessed in Christchurch, plus 100 term born controls. VLBW adults with ROP had reduced VA compared with no ROP and controls (mean logMAR score (SD); 0.003 (0.19), -0.021 (0.16), -0.078 (0.09), P=0.001). There were no differences in myopia (>2 D) between the groups but high myopia (>5 D) was confined to those with ROP. VLBW adults with ROP drove a car less often and had higher difficulties with everyday activities scores due to eyesight. Between 7-8 and 27-29 years rates of reduced VA were stable but myopia increased. Former VLBW young adults with ROP have ongoing problems with vision affecting daily living and should continue in regular ophthalmological review. ACTRN12612000995875, Pre-results . © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Myopia prevention, near work, and visual acuity of college students: integrating the theory of planned behavior and self-determination theory.

PubMed

Chan, Derwin King-Chung; Fung, Ying-Ki; Xing, Suxuan; Hagger, Martin S

2014-06-01

There has been little research examining the psychological antecedents of safety-oriented behavior aimed at reducing myopia risk. This study utilizes self-determination theory (SDT) and the theory of planned behavior (TPB) to understand the role of motivational and social-cognitive factors on individuals' near-work behavior. Adopting a prospective design, undergraduate students (n = 107) completed an initial questionnaire based on SDT in week 1, a second questionnaire containing measures of TPB variables in week 2, and objective measures of reading distance and visual acuity in week 6. The data were analyzed by variance-based structural equation modeling. The results showed that perceived autonomy support and autonomous motivation from SDT significantly predicted attitude, subjective norm, and perceived behavioral control from the TPB. These social-cognitive factors were significantly associated with intention and intention significantly predicted reading distance. The relationships in the model held when controlling for visual acuity. In conclusion, the integrated model of SDT and the TPB may help explain myopia-preventive behaviors.

Myopia, lifestyle, and schooling in students of Chinese ethnicity in Singapore and Sydney.

PubMed

Rose, Kathryn A; Morgan, Ian G; Smith, Wayne; Burlutsky, George; Mitchell, Paul; Saw, Seang-Mei

2008-04-01

To compare the prevalence and risk factors for myopia in 6- and 7-year-old children of Chinese ethnicity in Sydney and Singapore. Two cross-sectional samples of age- and ethnicity-matched primary school children participated: 124 from the Sydney Myopia Study and 628 from the Singapore Cohort Study on the Risk Factors for Myopia. Cycloplegic autorefraction was used to determine myopia prevalence (spherical equivalent < or = -0.5 diopter). Lifestyle activities were ascertained by questionnaire. The prevalence of myopia in 6- and 7-year-old children of Chinese ethnicity was significantly lower in Sydney (3.3%) than in Singapore (29.1%) (P < .001). The prevalence of myopia in 1 or more parents was 68% in Sydney and 71% in Singapore. Children in Sydney read more books per week (P < .001) and did more total near-work activity (P = .002). Children in Sydney spent more time on outdoor activities (13.75 vs 3.05 hours per week; P < .001), which was the most significant factor associated with the differences in the prevalence of myopia between the 2 sites. The lower prevalence of myopia in Sydney was associated with increased hours of outdoor activities. We hypothesize that another factor contributing to the differences in the prevalence of myopia may be the early educational pressures found in Singapore but not in Sydney.

Characteristics of Refractive Errors in a Population of Adults in the Central Region of Poland.

PubMed

Nowak, Michal S; Jurowski, Piotr; Grzybowski, Andrzej; Smigielski, Janusz

2018-01-08

Background : To investigate the distribution of refractive errors and their characteristics in older adults from a Polish population. Methods : The study design was a cross-sectional study. A total of 1107 men and women were interviewed and underwent detailed ophthalmic examinations, 998 subjects underwent refraction. Myopia was defined as spherical equivalent (SER) refraction ≤-0.5 dioptres (D) and hyperopia was defined as SER ≥+0.5 dioptres (D). Results : Among those who were refracted the distribution of myopia and hyperopia was 24.1% (95% CI 21.4-26.7) and 37.5% (95% CI 34.5-40.5), respectively. Myopia decreased from 28.7% in subjects aged 35-59 years to 19.3% in those aged 60 years or older and hyperopia increased from 21.8% at 35-59 years of age to 53.3% in subjects aged ≥60 years. Multiple regression analysis showed decreasing age (OR 0.98, 95% CI 0.96-1.00), female gender (OR 1.87, 95% CI 1.18-2.95) and presence of cataract (OR 2.40, 95% CI 1.24-4.63) were independent risk factors associated with myopia. Conclusions : The distribution of refractive errors found in our study is similar to those reported in other Caucasian populations and differs from Asian populations. Myopia was positively associated with younger age, female gender and presence of cataract.

An evidence-based update on myopia and interventions to retard its progression

PubMed Central

Leo, Seo-Wei; Young, Terri L.

2011-01-01

Summary Myopia is the most common human eye disorder. With its increasing prevalence and earlier age-of-onset in recent birth cohorts, myopia now affects almost 33% of adult individuals in the United States, and epidemic proportions of 85% to 90% adult individuals in Asian cities. Unlike children in Western populations, where the prevalence of myopia is very low (less than 5%), Asian children have prevalences as high as 29% in 7-year-olds. In addition to the direct economic and social burdens of myopia, associated ocular complications may lead to substantial vision loss. This workshop summarizes the current literature regarding myopia epidemiology, genetics, animal model studies, risk factors, and clinical treatments. Published treatment strategies to retard the progression of myopia in children, such as pharmacologic agents, progressive addition lenses, neural adaptation programs are outlined. PMID:21596297

Assessment of corneal biomechanical properties and intraocular pressure in myopic spanish healthy population.

PubMed

Del Buey, María A; Lavilla, Laura; Ascaso, Francisco J; Lanchares, Elena; Huerva, Valentín; Cristóbal, José A

2014-01-01

Purpose. To examine biomechanical parameters of the cornea in myopic eyes and their relationship with the degree of myopia in a western healthy population. Methods. Corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann correlated intraocular pressure (IOP), and corneal compensated IOP (IOPcc) were measured using the ocular response analyzer (ORA) in 312 eyes of 177 Spanish subjects aged between 20 and 56 years. Refraction was expressed as spherical equivalent (SE), which ranged from 0 to -16.50 diopters (D) (mean: -3.88 ± 2.90 D). Subjects were divided into four groups according to their refractive status: group 1 or control group: emmetropia (-0.50 ≤ SE < 0.50); group 2: low myopia (-0.75 ≤ SE < 3.00 D); group 3: moderate myopia (-3.00 ≤ SE ≤ -6.00 D); and group 3: high myopia (SE greater than -6.00 D). We analyzed the relationship between corneal biomechanics measured with ORA and SE. Results. CH in the emmetropia, low myopia, moderate myopia, and high myopia groups was 11.13 ± 0.98, 11.49 ± 1.25, 10.52 ± 1.54, and 10.35 ± 1.33 mmHg, respectively. CH in the highly myopic group was significantly lower than that in the emmetropic group (P = 0.07) and low myopic group (P = 0.035); however, there were no differences with the moderate myopic group (P = 0.872). There were no statistically significant differences regarding IOP among the four groups (P > 0.05); nevertheless, IOPcc was significantly higher in the moderately myopic (15.47 ± 2.47 mmHg) and highly myopic (16.14 ± 2.59 mmHg) groups than in the emmetropia (15.15 ± 2.06 mmHg) and low myopia groups (14.53 ± 2.37 mmHg). No correlation between age and the measured parameters was found. CH and IOPcc were weakly but significantly correlated with SE (r = 0.171, P = 0.002 and r = -0.131, P = 0.021, resp.). Conclusions. Present study showed only a very weak, but significant, correlation between CH and refractive error, with CH being lower in both moderately and highly myopic eyes than that in the emmetropic and low myopic eyes. These changes in biomechanical properties of the cornea may have an impact on IOP measurement, increasing the risk of glaucoma.

Outdoor activity and myopia among primary students in rural and urban regions of Beijing.

PubMed

Guo, Yin; Liu, Li Juan; Xu, Liang; Lv, Yan Yun; Tang, Ping; Feng, Yi; Meng, Meng; Jonas, Jost B

2013-02-01

To assess associations among outdoor activity, ocular biometric parameters, and myopia among grade 1 and grade 4 primary students in Beijing. School-based, cross-sectional study. A total of 382 grade 1 and 299 grade 4 children participated in the study. The children underwent a comprehensive eye examination, including ocular biometry by optical low-coherence reflectometry and noncycloplegic refractometry. Parents and children participated in a detailed interview, including questions on time spent indoors and outdoors. Factors associated with myopia. The study included 681 children, with 382 (56.1%) students from grade 1 (mean age, 6.3 ± 0.5 years; range, 5-8 years) and 299 students from grade 4 (mean age, 9.4 ± 0.7 years; range, 8-13 years); 370 students (54.3%) lived in the urban region. The mean daily time spent outdoors was 1.6 ± 0.8 hours (range, 0.5-5.1 hours). In multivariate analysis, axial length was significantly associated with older age (P<0.001; standardized β coefficient, 0.28), taller body height (P = 0.001; β, 0.18), maternal myopia (P = 0.03; β, 0.09), and urban region of habitation (P<0.001; β, -0.21), or alternatively to the region of habitation, with less time spent outdoors (P = 0.001; β, -0.16) and more time spent indoors studying (P = 0.02; β, 0.10). The axial length-to-corneal curvature radius ratio was associated with older age, urban region of habitation, maternal and paternal myopia, and paternal level of education. Presence of myopia (defined as refractive error ≤-1 diopters in the right eye) was associated with older age (P<0.001; odds ratio [OR], 1.45; 95% confidence interval [CI], 1.24-1.69), maternal myopia (P<0.001; OR, 2.99; 95% CI, 1.94-5.35), and urban region of habitation (P<0.001; OR, 0.17; 95% CI, 0.11-0.26), or alternatively to the region of habitation, with less time spent outdoors (P<0.001; OR, 0.32; 95% CI, 0.21-0.48) and more time spent indoors studying (P<0.001; OR, 1.38; 95% CI, 1.09-1.75). Less outdoor activity, more indoor studying, older age, maternal myopia, and urban region of habitation were associated with longer ocular axial length and myopia in grade 1 and grade 4 primary school children in Greater Beijing. Remaining outdoors more (e.g., during school) may reduce the high prevalence of myopia in the young generation in Beijing. Copyright © 2013 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

[Contribution to Ehlers-Danlos syndrome (author's transl)].

PubMed

Fuxa, G; Brandt, H P

1975-02-01

A case of Ehler-Danlos syndrome with the rare complication of ablatio retinae without myopia is described. The alterations of the eye be Ehlers-Danlos syndrome, which are available in literature are demonstrated.

Localization and regulation of glucagon receptors in the chick eye and preproglucagon and glucagon receptor expression in the mouse eye.

PubMed

Feldkaemper, Marita P; Burkhardt, Eva; Schaeffel, Frank

2004-09-01

Myopia is a condition in which the eye is too long for the focal length of cornea and lens. Analysis of the messengers that are released by the retina to control axial eye growth in the animal model of the chicken revealed that glucagon-immunoreactive amacrine cells are involved in the retinal image processing that controls the growth of the sclera. It was found that the amount of retinal glucagon mRNA increased during treatment with positive lenses and pharmacological studies supported the idea that glucagon may act as a stop signal for eye growth. Glucagon exerts its regulatory effects by binding to a single type of glucagon receptor. In this study, we have sequenced the chicken glucagon receptor and compared its DNA and amino acid sequence with the human and mouse homologues. After sequencing about 80% of the receptor, we found a homology between 79.4 and 75.6% on cDNA level. At the protein level, about 73% of the amino acids were identical. Moreover, the cellular localization and regulation of the glucagon receptor in the chick retina was studied. In situ hybridization studies showed that many cells in the ganglion cell layer and inner nuclear layer, and some cells in the outer nuclear layer, express the receptor mRNA. Injection of the glucagon agonist Lys17,18,Glu21-glucagon induced a down-regulation of glucagon receptor mRNA content. Since the mouse would be an attractive mammalian model to study the biochemical and genetic basis of myopia, and because recent studies have demonstrated that form deprivation myopia can be induced, the expression of preproglucagon and glucagon receptor genes were also studied in the mouse retina and were found to be expressed.

Adenomatous Polyposis Coli Mutation Leads to Myopia Development in Mice

PubMed Central

Li, Jing; Zhu, Zhenzhen; Yang, Wenzhao; Zhou, Xiangtian; An, Jianhong; Huang, Furong; Wang, Qiongsi; Reinach, Peter S.; Li, Wei; Chen, Wensheng; Liu, Zuguo

2015-01-01

Myopia incidence in China is rapidly becoming a very serious sight compromising problem in a large segment of the general population. Therefore, delineating the underlying mechanisms leading to myopia will markedly lessen the likelihood of other sight compromising complications. In this regard, there is some evidence that patients afflicted with familial adenomatous polyposis (FAP), havean adenomatous polyposis coli (APC) mutation and a higher incidence of myopia. To clarify this possible association, we determined whether the changes in pertinent biometric and biochemical parameters underlying postnatal refractive error development in APCMin mice are relevant for gaining insight into the pathogenesis of this disease in humans. The refraction and biometrics in APCMin mice and age-matched wild-type (WT) littermates between postnatal days P28 and P84 were examined with eccentric infrared photorefraction (EIR) and customized optical coherence tomography (OCT). Compared with WT littermates, the APCMin mutated mice developed myopia (average -4.64 D) on P84 which was associated with increased vitreous chamber depth (VCD). Furthermore, retinal and scleral changes appear in these mice along with: 1) axial length shortening; 2) increased retinal cell proliferation; 3) and decreased tyrosine hydroxylase (TH) expression, the rate-limiting enzyme of DA synthesis. Scleral collagen fibril diameters became heterogeneous and irregularly organized in the APCMin mice. Western blot analysis showed that scleral alpha-1 type I collagen (col1α1) expression also decreased whereas MMP2 and MMP9 mRNA expression was invariant. These results indicate that defective APC gene function promotes refractive error development. By characterizing in APCMin mice ocular developmental changes, this approach provides novel insight into underlying pathophysiological mechanisms contributing to human myopia development. PMID:26495845

Comparison of visual acuity of the patients on the first day after sub-Bowman keratomileusis or laser in situ keratomileusis.

PubMed

Zhao, Wei; Wu, Ting; Dong, Ze-Hong; Feng, Jie; Ren, Yu-Feng; Wang, Yu-Sheng

2016-01-01

To compare recovery of the visual acuity in patients one day after sub-Bowman keratomileusis (SBK) or laser in situ keratomileusis (LASIK). Data from 5923 eyes in 2968 patients that received LASIK (2755 eyes) or SBK (3168 eyes) were retrospectively analyzed. The eyes were divided into 4 groups according to preoperative spherical equivalent: between -12.00 to -9.00 D, extremely high myopia (n=396, including 192 and 204 in SBK and LASIK groups, respectively); -9.00 to -6.00 D, high myopia (n=1822, including 991 and 831 in SBK and LASIK groups, respectively), -6.00 to -3.00 D, moderate myopia (n=3071, including 1658 and 1413 in SBK and LASIK groups, respectively), and -3.00 to 0.00 D, low myopia (n=634, including 327 and 307 in SBK and LASIK groups, respectively). Uncorrected logMAR visual acuity values of patients were assessed under standard natural light. Analysis of variance was used for comparisons among different groups. Uncorrected visual acuity values were 0.0115±0.1051 and 0.0466±0.1477 at day 1 after operation for patients receiving SBK and LASIK, respectively (P<0.01); visual acuity values of 0.1854±0.1842, 0.0615±0.1326, -0.0033±0.0978, and -0.0164±0.0972 were obtained for patients in the extremely high, high, moderate, and low myopia groups, respectively (P<0.01). In addition, significant differences in visual acuity at day 1 after operation were found between patients receiving SBK and LASIK in each myopia subgroup. Compared with LASIK, SBK is safer and more effective, with faster recovery. Therefore, SBK is more likely to be accepted by patients than LASIK for better uncorrected visual acuity the day following operation.

Prevention of myopia by partial correction of hyperopia: a twins study.

PubMed

Medina, Antonio

2018-04-01

To confirm the prediction of emmetropization feedback theory that myopia can be prevented by correcting the hyperopia of a child at risk of becoming myopic. We conducted such myopia prevention treatment with twins at risk. Their hyperopia was partially corrected by one half at age 7 and in subsequent years until age 16. Hyperopia progressively decreased in all eyes as expected. None of the twins developed myopia. The spherical equivalent refractions of the followed eyes were +1 and +1.25 D at age 16. Feedback theory accurately predicted these values. The treatment of the twins with partial correction of their hyperopia was successful. Prevention of myopia with this technique is relatively simple and powerful. The use of this myopia prevention treatment has no adverse effects. This prevention treatment is indicated in children with a hyperopic reserve at risk of developing myopia.

Myopia and depressive symptoms among older Chinese adults.

PubMed

Wu, Yin; Ma, Qinghua; Sun, Hong-Peng; Xu, Yong; Niu, Mei-E; Pan, Chen-Wei

2017-01-01

Few population-based data support the hypothesis that refractive errors are associated with depressive symptoms. We aim to assess the impact of myopia on the risk of having depressive symptoms in a community-based cohort of elderly Chinese. A community-based cross-sectional study of 4611 Chinese adults aged 60 years or older was conducted. Depressive symptoms were measured using the 9-item Patient Health Questionnaire (PHQ-9) depression scale in 4597 adults. Refraction was determined by auto-refraction followed by subjective refraction. Myopia was defined as spherical equivalent (SE) < -0.50 diopters (D) and high myopia as SE < -6.00 D. After adjusting for age, gender, education, lifestyle-related exposures, presenting visual acuity and age-related cataract, myopic adults were more likely to have any depressive symptoms compared with non-myopic ones (odds ratio = 1.39; 95% confidence interval 1.04, 1.92). There were no significant differences in the risk of having any depressive symptoms between those with and without high myopia. Myopia or high myopia was not associated with having moderate depressive symptoms. The impact of myopia on depressive symptoms was stronger in adults with no formal education compared with those with formal education. Myopia was related with the presence of depressive symptoms among older adults.

Muscarinic cholinergic receptor (M2) plays a crucial role in the development of myopia in mice

PubMed Central

Barathi, Veluchamy A.; Kwan, Jia Lin; Tan, Queenie S. W.; Weon, Sung Rhan; Seet, Li Fong; Goh, Liang Kee; Vithana, Eranga N.; Beuerman, Roger W.

2013-01-01

SUMMARY Myopia is a huge public health problem worldwide, reaching the highest incidence in Asia. Identification of susceptible genes is crucial for understanding the biological basis of myopia. In this paper, we have identified and characterized a functional myopia-associated gene using a specific mouse-knockout model. Mice lacking the muscarinic cholinergic receptor gene (M2; also known as Chrm2) were less susceptible to lens-induced myopia compared with wild-type mice, which showed significantly increased axial length and vitreous chamber depth when undergoing experimental induction of myopia. The key findings of this present study are that the sclera of M2 mutant mice has higher expression of collagen type I and lower expression of collagen type V than do wild-type mice and mice that are mutant for other muscarinic subtypes, and, therefore, M2 mutant mice were resistant to the development of experimental myopia. Pharmacological blockade of M2 muscarinic receptor proteins retarded myopia progression in the mouse. These results suggest for the first time a role of M2 in growth-related changes in extracellular matrix genes during myopia development in a mammalian model. M2 receptor antagonists might thus provide a targeted therapeutic approach to the management of this refractive error. PMID:23649821

MiSight Assessment Study Spain (MASS). A 2-year randomized clinical trial.

PubMed

Ruiz-Pomeda, Alicia; Pérez-Sánchez, Belén; Valls, Isabel; Prieto-Garrido, Francisco Luis; Gutiérrez-Ortega, Ramón; Villa-Collar, César

2018-05-01

To compare myopia progression in children randomized to MiSight contact lenses (CLs) versus children corrected with single-vision spectacles (SV) over a 2-year period. Subjects aged 8 to 12 with myopia (-0.75 to -4.00 D sphere) and astigmatism (< -1.00 D cylinder) were assigned to the lens study group (MiSight) or the control group (single vision). Measurements of visual acuity and subjective refraction were taken at 6-month intervals, and axial length, anterior chamber, corneal power, and cycloplegic autorefraction were measured at the baseline, 12-month, and 24-month visits. Eighty-nine subjects were recruited. Forty-fix children were assigned to the MiSight group, and 33 to the single-vision spectacle group. In total, 74 children completed the clinical trial, with the following parameters at the beginning of the study: n =  41 in the MiSight group (age: 11.01 ± 1.23 years, spherical equivalent: -2.16 ± 0.94 D, gender: male: 21, female: 20) and n = 33 in the single-vision group (age: 10.12 ± 1.38 years, spherical equivalent: -1.75 ± 0.94 D, gender: male: 12, female: 21). After 2 years of follow-up, myopia progressed slowly in the MiSight group compared to the control group (0.45 D vs 0.74 D, p < 0.001) and there was less axial elongation in the MiSight group compared to the single-vision group (0.28 mm vs 0.44 mm, p < 0.001). Therefore, use of MiSight CLs produced lower myopia progression (39.32%) and lower axial growth of the eye (36.04%) at 2 years compared to spectacle use. MiSight contact lens wear reduces axial elongation and myopia progression in comparison to distance single-vision spectacles in children. ClinicalTrials.gov Identifier: NCT01917110.

[Use of Plusoptix as a screening method for refractive ambliopia].

PubMed

Bogdănici, T; Tone, Silvia; Miron, Mihaela; Boboc, Mihaela; Bogdănici, Camelia

2012-01-01

Highlighting the differences in the objective refraction using the Plusoptix AO9 comparing them with the refraction performed with TOPCON KR-8900 autorefractor. Prospective study for 3 months held in the Ophthalmology Clinic in Iasi, Hospital Sf. Spiridon on a total of 39 children (21 girls and 18 boys) with mean age of 10.61 +/- 5.67 years. Clinical parameters: sex, age, objective refraction obtained with Plusoptix and with autorefractor corrected visual acuity (with different methods depending on each patient age), ortoptic examination (strabic deviation, binocular vision), the presence of symetry/asymetry while measuring with Plusoptix. The results were statistically processed by F-TEST calculating the correlation coefficient, standard deviation, significance level (using the spherical equivalent of the obtained values). Age limits of the studied cases ranged between 2-23 years. Visual acuity of children who had cooperate was between 0.2-1 with correction, achieving best values on right eye than left eye. 8 cases (20.51%) had large differences between measurements made with Plusoptix and autorefractor, half of that (4 cases) had strabismus. Three of these cases were with small hypermetropia and one with small myopia (Plusoptix shows a lower value). In 2 cases occurred higher differences (about 2-2,5D) between the 2 measurements, in patients with average hypermetropia. Plusoptix refraction was not possible at high hypermetropia or high myopia. This type of determining objective refraction using Plusoptix is a useful method of screening for discovery of refractive errors that can cause refractive amblyopia in young children and in those cases with a difficult collaboration. Because there are differences betweeti this 2 methods, for children with refractive errors are recommended further exploration to determine the appropriate optical correction. Plusoptix is a limited method because it cannot detect the exact values in those cases with high hypermetropia or high myopia.

Identification of proteins in the aqueous humor associated with cataract development using iTRAQ methodology.

PubMed

Xiang, Minhong; Zhang, Xingru; Li, Qingsong; Wang, Hanmin; Zhang, Zhenyong; Han, Zhumei; Ke, Meiqing; Chen, Xingxing

2017-05-01

Proteins in the aqueous humor (AH) are important in the induction of cataract development. The identification of cataract-associated proteins assists in identifying patients and predisposed to the condition and improve treatment efficacy. Proteomics analysis has previously been used for identifying protein markers associated with eye diseases; however, few studies have examined the proteomic alterations in cataract development due to high myopia, glaucoma and diabetes. The present study, using the isobaric tagging for relative and absolute protein quantification methodology, aimed to examine cataract-associated proteins in the AH from patients with high myopia, glaucoma or diabetes, and controls. The results revealed that 445 proteins were identified in the AH groups, compared with the control groups, and 146, 264 and 130 proteins were differentially expressed in the three groups of patients, respectively. In addition, 44 of these proteins were determined to be cataract‑associated, and the alterations of five randomly selected proteins were confirmed using enzyme-linked immunosorbent assays. The biological functions of these 44 cataract-associated proteins were analyzed using Gen Ontology/pathways annotation, in addition to protein‑protein interaction network analysis. The results aimed to expand current knowledge of the pathophysiologic characteristics of cataract development and provided a panel of candidates for biomarkers of the disease, which may assist in further diagnosis and the monitoring of cataract development.

Risk Factors for Developing Myopia among Schoolchildren in Yerevan and Gegharkunik Province, Armenia.

PubMed

Giloyan, Aida; Harutyunyan, Tsovinar; Petrosyan, Varduhi

2017-04-01

Myopia is a complex condition leading to visual impairment and blindness. This study assessed the prevalence of and risk factors for myopia among schoolchildren in urban and rural areas of Armenia. A cross-sectional interviewer-administered survey together with eye screenings was conducted among schoolchildren in the capital Yerevan and in Gegharkunik Province. The study used multi-stage random sampling to obtain the sample of 1260 schoolchildren. Study questionnaires were developed based on the Sydney Myopia Study questionnaire. Continuous reading was defined as the average number of hours spent reading or on near work without a break. Children underwent measurements of visual acuity using a Golovin-Sivtsev eye chart, cycloplegic retinoscopy, and dilated fundus examination. The mean age of the children was 13 years, and myopia was present in 18.1%. The prevalence of myopia was higher among Yerevan children (23.3%) than those living in Gegharkunik Province (12.5%). In the adjusted model, myopia was significantly associated with age (odds ratio, OR, 1.11, 95% confidence interval, CI, 1.04-1.18), region (OR 2.40, 95% CI 1.62-3.57), school achievement (OR 1.62, 95% CI 1.05-2.51), parental myopia (OR 2.89, 95% CI 1.79-4.69), and continuous reading (OR 1.99, 95% CI 1.31-3.02), but not near work (OR 0.97, 95% CI 0.89-1.05). The study found that a positive family history of myopia and environmental factors had independent associations with myopia. The number of near work hours did not play a major role in the development of myopia, but length of time of focused continuous reading did.

Incidence and progression of myopia and associated factors in urban school children in Delhi: The North India Myopia Study (NIM Study).

PubMed

Saxena, Rohit; Vashist, Praveen; Tandon, Radhika; Pandey, Ravindra M; Bhardawaj, Amit; Gupta, Vivek; Menon, Vimala

2017-01-01

To evaluate the incidence and progression of myopia and factors associated with progression of myopia in school going children in Delhi. Prospective longitudinal study of 10,000 school children aged 5 to 15 years screened after an interval of 1 year to identify new myopes (Spherical Equivalent≤ -0.5D) and progression of myopia in previously diagnosed myopic children. Association between risk factors and progression was analyzed using adjusted odds ratio. Of the 9,616 children re-screened (97.3% coverage), annual incidence of myopia was 3.4%with mean dioptric change of -1.09 ± 0.55. There was a significant higher incidence of myopia in younger children compared to older children (P = 0.012) and among girls compared to boys (P = 0.002). Progression was observed in 49.2%children with mean dioptric change of -0.27 ± 0.42 diopters. The demographic and behavioral risk factors were analyzed for children with progression (n = 629) and adjusted odds ratio values were estimated. Hours of reading-writing/week (p<0.001), use of computers/ video games (P<0.001) and watching television (P = 0.048) were significant risk factors for progression of myopia. Outdoor activities / time spent outdoors> 2 hours in a day were protective with an inverse association with progression of myopia (P< 0.001). Myopia is an important health issue in India and is associated with long hours of reading and screen time with use of computers and video games. An annual eye vision screening should be conducted, and outdoor activities be promoted to prevent the increase of myopia among school children.

Juvenile myopia progression, risk factors and interventions.

PubMed

Myrowitz, Elliott H

2012-07-01

The development and progression of early onset myopia is actively being investigated. While myopia is often considered a benign condition it should be considered a public health problem for its visual, quality of life, and economic consequences. Nearly half of the visually impaired population in the world has uncorrected refractive errors, with myopia a high percent of that group. Uncorrected visual acuity should be screened for and treated in order to improve academic performance, career opportunities and socio-economic status. Genetic and environmental factors contribute to the onset and progression of myopia. Twin studies have supported genetic factors and research continues to identify myopia genetic loci. While multiple myopia genetic loci have been identified establishing myopia as a common complex disorder, there is not yet a genetic model explaining myopia progression in populations. Environmental factors include near work, education levels, urban compared to rural location, and time spent outdoors. In this field of study where there continues to be etiology controversies, there is recent agreement that children who spend more time outdoors are less likely to become myopic. Worldwide population studies, some completed and some in progress, with a common protocol are gathering both genetic and environmental cohort data of great value. There have been rapid population changes in prevalence rates supporting an environmental influence. Interventions to prevent juvenile myopia progression include pharmacologic agents, glasses and contact lenses. Pharmacological interventions over 1-2 year trials have shown benefits. Peripheral vision defocus has been found to affect the emmetropization process and may be affected by wearing glasses or contacts. Accommodation accuracy also has been implicated in myopia progression. Further research will aim to assess both the role and interaction of environmental influences and genetic factors.

Refractive errors in 3-6 year-old Chinese children: a very low prevalence of myopia?

PubMed

Lan, Weizhong; Zhao, Feng; Lin, Lixia; Li, Zhen; Zeng, Junwen; Yang, Zhikuan; Morgan, Ian G

2013-01-01

To examine the prevalence of refractive errors in children aged 3-6 years in China. Children were recruited for a trial of a home-based amblyopia screening kit in Guangzhou preschools, during which cycloplegic refractions were measured in both eyes of 2480 children. Cycloplegic refraction (from 3 to 4 drops of 1% cyclopentolate to ensure abolition of the light reflex) was measured by both autorefraction and retinoscopy. Refractive errors were defined as followed: myopia (at least -0.50 D in the worse eye), hyperopia (at least +2.00 D in the worse eye) and astigmatism (at least 1.50 D in the worse eye). Different definitions, as specified in the text, were also used to facilitate comparison with other studies. The mean spherical equivalent refractive error was at least +1.22 D for all ages and both genders. The prevalence of myopia for any definition at any age was at most 2.5%, and lower in most cases. In contrast, the prevalence of hyperopia was generally over 20%, and declined slightly with age. The prevalence of astigmatism was between 6% and 11%. There was very little change in refractive error with age over this age range. Previous reports of less hyperopic mean spherical equivalent refractive error, and more myopia and less hyperopia in children of this age may be due to problems with achieving adequate cycloplegia in children with dark irises. Using up to 4 drops of 1% cyclopentolate may be necessary to accurately measure refractive error in paediatric studies of such children. Our results suggest that children from all ethnic groups may follow a similar pattern of early refractive development, with little myopia and a hyperopic mean spherical equivalent over +1.00 D up to the age of 5-6 years in most conditions.

Myopia Stabilization and Associated Factors Among Participants in the Correction of Myopia Evaluation Trial (COMET)

PubMed Central

2013-01-01

Purpose. To use the Gompertz function to estimate the age and the amount of myopia at stabilization and to evaluate associated factors in the Correction of Myopia Evaluation Trial (COMET) cohort, a large ethnically diverse group of myopic children. Methods. The COMET enrolled 469 ethnically diverse children aged 6 to younger than 12 years with spherical equivalent refraction between −1.25 and −4.50 diopters (D). Noncycloplegic refraction was measured semiannually for 4 years and annually thereafter. Right eye data were fit to individual Gompertz functions in participants with at least 6 years of follow-up and at least seven refraction measurements over 11 years. Function parameters were estimated using a nonlinear least squares procedure. Associated factors were evaluated using linear regression. Results. In total, 426 participants (91%) had valid Gompertz curve fits. The mean (SD) age at myopia stabilization was 15.61 (4.17) years, and the mean (SD) amount of myopia at stabilization was −4.87 (2.01) D. Ethnicity (P < 0.0001) but not sex or the number of myopic parents was associated with the age at stabilization. Ethnicity (P = 0.02) and the number of myopic parents (P = 0.01) but not sex were associated with myopia magnitude at stabilization. At stabilization, African Americans were youngest (mean age, 13.82 years) and had the least myopia (mean, −4.36 D). Participants with two versus no myopic parents had approximately 1.00 D more myopia at stabilization. The age and the amount of myopia at stabilization were correlated (r = −0.60, P < 0.0001). Conclusions. The Gompertz function provides estimates of the age and the amount of myopia at stabilization in an ethnically diverse cohort. These findings should provide guidance on the time course of myopia and on decisions regarding the type and timing of interventions. PMID:24159085

Relationship of lifestyle and body stature growth with the development of myopia and axial length elongation in Taiwanese elementary school children.

PubMed

Huang, Chung-Ying; Hou, Chiun-Ho; Lin, Ken-Kuo; Lee, Jiahn-Shing; Yang, Meng-Ling

2014-08-01

The development of myopia and growth of the eye, occur at a time when body stature is increasing. To investigate the relationship of lifestyle and body growth with axial elongation and myopia development among schoolchildren aged 7 to 9 years. Prospective study. Children in elementary schools without serious eye disorders were invited to participate. We measured cycloplegic refraction, corneal curvature, intraocular pressure, axial length, body height, and weight. Questionnaires about the children's daily lifestyles, family members' myopia and parents' socio-demographic status were completed. The children were followed up every 6 months in a 3-year period. Bivariate correlations, simple and multiple regression. Eighty-eight children participated in this study. Forty-eight were myopic at the beginning of the study, and their myopia correlated with longer axial length and parental myopia (P = 0.015, 0.012). Sixty-five children (74%) completed the study, and the rates of change per year were -0.43 ± 0.58 (mean + standard deviation) diopters in spherical equivalence, 0.32 ± 0.25 mm in axial length (AL), 5.73 ± 2.71 cm in body height, and 3.84 ± 2.23 kg in weight. The axial length change was positively correlated with the height change (P < 0.001). The myopia shift was correlated to axial length change (P = 0.000) but not correlated to height change. Using multiple regression test, near work was the only significant risk factor for myopia progression (P = 0.022). Our study showed that body height increment was correlated to axial length elongation but not to myopia shift in children aged 7-9 years. Genetic factors such as parental myopia and body height had a possible influence on myopia development, and the environment factor as near work intensity was related to myopia progression.

Education-Related Parameters in High Myopia: Adults versus School Children.

PubMed

Jonas, Jost B; Xu, Liang; Wang, Ya Xing; Bi, Hong Sheng; Wu, Jian Feng; Jiang, Wen Jun; Nangia, Vinay; Sinha, Ajit; Zhu, Dan; Tao, Yong; Guo, Yin; You, Qi Sheng; Wu, Li Juan; Tao, Li Xin; Guo, Xiu Hua; Ohno-Matsui, Kyoko; Panda-Jonas, Songhomitra

2016-01-01

Since high myopia in the younger generation may differ etiologically from high myopia in older generations, we examined whether education-related parameters differ between high myopia in today´s school children and high pathological myopia in today´s elderly generation. The investigation included the adult populations of the population-based Beijing Eye Study (BES) (3468 adults;mean age:64.6±9.8years;range:50-93years) and Central India Eye and Medical Study (CIEMS) (4711 adults;age:49.±13.2years;range:30-100years), and the children and teenager populations of the Shandong Children Eye Study (SCES) (6026 children;age:9.7±3.3years;range:4-18years;cycloplegic refractometry), Gobi Desert Children Eye Study (1565;age:11.9±3.5years;range:6-21 years;cycloplegic refractometry), Beijing Pediatric Eye Study (681 children;age:7.7±1.6years;range:5-13 years;non-cycloplegic refractometry,calculation of axial length to corneal curvature radius ratio), Beijing Children Eye Study (15066 children;age:13.2±3.4years;range:7-18years;non-cycloplegic refractometry), Beijing High School Teenager Eye Study (4677 children;age:16.9±0.7years;range:16-18years;non-cycloplegic refractometry). In the BES and CIEMS, educational level did not differ significantly between, or was significantly lower in the highly myopic group (myopic refractive error ≥6 diopters) than in the non-highly myopic group. In all non-adult study populations, higher prevalence of high myopia was significantly associated with higher degree of education related parameters such as attendance of high-level schools, and more time spent for indoors near work versus time spent outdoors. Comparing associations of old or genetic high myopia in adults with new or acquired high myopia in school children revealed that education-related parameters did not show a clear association with old or genetic high myopia, while in contrast, new high myopia showed strong associations with education. It confirms previous studies that the two forms of high myopia not only differed in age of onset, but also in associations with education as well. The data support the notion of two types of high myopia. Future studies may assess whether the risk of pathologic myopic maculopathy and high myopia associated open-angle glaucoma differs between both types of high myopia.

Topical Atropine in the Control of Myopia

PubMed Central

GALVIS, Virgilio; TELLO, Alejandro; PARRA, M. Margarita; MERAYO-LLOVES, Jesus; LARREA, Jaime; JULIAN RODRIGUEZ, Carlos; CAMACHO, Paul Anthony

2016-01-01

Atropine has been used for more than a century to arrest myopia progression. Compelling evidence of its protective effect has been reported in well-designed clinical studies, mainly performed during the last two decades. However, its exact mechanism of action has not been determined. Experimental findings have shown that the mechanism is not related to accommodation, as was thought for decades. A review of the published literature revealed a significant amount of evidence supporting its safety and efficacy at a concentration of 1.0%, and at lower concentrations (as low as 0.01%). PMID:28293653

Cycloplegic refraction is the gold standard for epidemiological studies.

PubMed

Morgan, Ian G; Iribarren, Rafael; Fotouhi, Akbar; Grzybowski, Andrzej

2015-09-01

Many studies on children have shown that lack of cycloplegia is associated with slight overestimation of myopia and marked errors in estimates of the prevalence of emmetropia and hyperopia. Non-cycloplegic refraction is particularly problematic for studies of associations with risk factors. The consensus around the importance of cycloplegia in children left undefined at what age, if any, cycloplegia became unnecessary. It was often implicitly assumed that cycloplegia is not necessary beyond childhood or early adulthood, and thus, the protocol for the classical studies of refraction in older adults did not include cycloplegia. Now that population studies of refractive error are beginning to fill the gap between schoolchildren and older adults, whether cycloplegia is required for measuring refractive error in this age range, needs to be defined. Data from the Tehran Eye Study show that, without cycloplegia, there are errors in the estimation of myopia, emmetropia and hyperopia in the age range 20-50, just as in children. Similar results have been reported in an analysis of data from the Beaver Dam Offspring Eye Study. If the only important outcome measure of a particular study is the prevalence of myopia, then cycloplegia may not be crucial in some cases. But, without cycloplegia, measurements of other refractive categories as well as spherical equivalent are unreliable. In summary, the current evidence suggests that cycloplegic refraction should be considered as the gold standard for epidemiological studies of refraction, not only in children, but in adults up to the age of 50. © 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Visual analysis of orthokeratology on myopia reduction for aviators

NASA Astrophysics Data System (ADS)

Mitsui, Iwane

2005-04-01

Ortho-K was indicated for sixty eyes of thirty aviators, twenty-one pilots and nine flight attendants, with age of 34.5 on the average. Uncorrected visual acuity (UCVA) was originally 20/30 or worse in all cases. The mean spherical equivalent (SE) was -3.69 Diopters (D). The same ophthalmologist designed full costumed reverse geometry Advanced Orthokeratology lenses for each patient. All the patients were followed at least two years wearing of Advanced Ortho-K lenses. The follow up examinations on auto-refraction, auto-keratometry, uncorrected and corrected visual acuity, intra-ocular pressure, corneal endothelial cells, corneal thickness and curve, and corneal shape were performed in the morning, 10am to 12am. 94% of the patients improved in UCVA up to 20/20 or better, 87% of them improved up to 20/15 or better, and 67% of them improved up to 20/10. The mean SEs improved to -1.90+/-1.00D during six months, -1.49+/-1.03D during one year, and -0.73+/-0.94D during two years. Astigmatism slightly increased by 0.38D on the average, however, it did not cause any serious problems for aviation tasks even during night. Intraocular pressure did not increase and corneal endothelial cells did not decrease. Other ophthalmologic examinations showed normal conditions and any complications were not observed throughout the period. Advanced Ortho-K was evaluated to be safe and effective enough for also aviators with myopia. It can be recommended one of the options of reduction of myopia for aviators. Evaluations on night vision and night glare are planned for further studies.

[Current recommendations for deceleration of myopia progression].

PubMed

Lagrèze, W A; Joachimsen, L; Schaeffel, F

2017-01-01

Epidemiologic data demonstrate a rise in myopia prevalence. Therefore interventions to reduce the risk of myopia and its progression are needed and increasingly often asked for. Systematic literature search via PubMed in MEDLINE. Myopia progression can be reduced by the following means which are listed according to their efficacy: (1) Atropine eye drops low dosed to avoid clinically relevant side effects, (2) optical means aiming at the correction of peripheral hyperopic defocus, e. g., multifocal contact lenses, and (3) increased daylight exposure. Daylight exposure reduces the risk of incident myopia. Children should be advised to spend sufficient time outdoors, especially before and in primary school. Myopia progression can be effectively attenuated by low-dose topical atropine and multifocal contact lenses.

Comparison of Visual Quality after Implantation of Big Bag and Akreos Adapt Intraocular Lenses in Patients with High Myopia.

PubMed

Ma, Shengsheng; Zheng, Dongjian; Lin, Ling; Meng, Fanjian; Yuan, Yonggang

2015-03-01

To compare vision quality following phacoemulsification cataract extraction and implantation of a Big Bag or Akreos Adapt intraocular lens (IOL) in patients diagnosed with high myopia complicated with cataract. This was a randomized prospective control study. The patients with high myopia. complicated with cataract, with axial length ≥ 28 mm, and corneal astigmatism ≤ 1D were enrolled and randomly divided into the Big Bag and Akreos Adapt IOL groups. All patients underwent phacoemulsification cataract extraction and lens implantation. At 3 months after surgery, intraocular high-order aberration was measured by a Tracey-iTrace wavefront aberrometer at a pupil diameter of 5 mm in an absolutely dark room and statistically compared between two groups. The images of the anterior segment of eyes were photographed with a Scheimpflug camera using Penta-cam three-dimensional anterior segment analyzer. The tilt and decentration of the IOL were calculated by Image-pro plus 6.0 imaging analysis software and statistically compared between two groups. In total, 127 patients (127 eyes), including 52 males and 75 females, were enrolled in this study. The total high-order aberration and coma in the Akreos Adapt group (59 eyes) were significantly higher compared with those in the Big Bag (P < 0.05). The clover and spherical aberration did not differ between the two groups (P > 0.05). The horizontal and vertical decentration were significantly smaller in the Big Bag lens group than in the Akreos Adapt group (both P < 0.05), whereas the tilt of IOL did not significantly differ between the two groups (P > 0.05). Both Big Bag and Akreos Adapt IOLs possess relatively good intraocular stability implanted in patients with high myopia. Compared with the Akreos Adapt IOL, the Big Bag IOL presents with smaller intraocular high-order aberration. Coma is the major difference between the two groups.

Preventing Myopia.

PubMed

Lagrèze, Wolf A; Schaeffel, Frank

2017-09-04

Nearsightedness (myopia) has become more common around the world recently, mainly because of changes in visual, educational, and recreational behavior. The question arises how the risk of myopia and its progression can be reduced. This would lessen the prevalence and severity of myopia and also lower the risk of secondary diseases that impair visual acuity. The PubMed/Medline database was selectively searched for pertinent literature. The risk of myopia is lowered by exposure to daylight and increased by activities performed at short visual distances (close-up work). A person with little exposure to daylight has a fivefold risk of developing myopia, which can rise as high as a 16-fold risk if that person also performs close-up work. Two meta-analyses and a large randomized clinical trial from Asia have shown that the progression of myopia over two years of observation can be lessened by up to 0.71 diopters by the administration of atropine eye drops in a concentration that has practically no serious side effects. At higher doses, myopia progresses more severely than in the placebo group after the cessation of therapy. This is an off-label treatment. A weaker effect on progression has been shown for multifocal optical corrections that include both a distance correction and a correction for near vision. Effective pharmacological and optical measures are now available to lessen the progression of myopia. The increasing prevalence of myopia should motivate pediatricians, parents, and schools to pay attention to risk factors such as close-up work and lack of daylight exposure, particularly in view of the increased use of digital media.

Patterns in longitudinal growth of refraction in Southern Chinese children: cluster and principal component analysis.

PubMed

Chen, Yanxian; Chang, Billy Heung Wing; Ding, Xiaohu; He, Mingguang

2016-11-22

In the present study we attempt to use hypothesis-independent analysis in investigating the patterns in refraction growth in Chinese children, and to explore the possible risk factors affecting the different components of progression, as defined by Principal Component Analysis (PCA). A total of 637 first-born twins in Guangzhou Twin Eye Study with 6-year annual visits (baseline age 7-15 years) were available in the analysis. Cluster 1 to 3 were classified after a partitioning clustering, representing stable, slow and fast progressing groups of refraction respectively. Baseline age and refraction, paternal refraction, maternal refraction and proportion of two myopic parents showed significant differences across the three groups. Three major components of progression were extracted using PCA: "Average refraction", "Acceleration" and the combination of "Myopia stabilization" and "Late onset of refraction progress". In regression models, younger children with more severe myopia were associated with larger "Acceleration". The risk factors of "Acceleration" included change of height and weight, near work, and parental myopia, while female gender, change of height and weight were associated with "Stabilization", and increased outdoor time was related to "Late onset of refraction progress". We therefore concluded that genetic and environmental risk factors have different impacts on patterns of refraction progression.

Patterns in longitudinal growth of refraction in Southern Chinese children: cluster and principal component analysis

PubMed Central

Chen, Yanxian; Chang, Billy Heung Wing; Ding, Xiaohu; He, Mingguang

2016-01-01

In the present study we attempt to use hypothesis-independent analysis in investigating the patterns in refraction growth in Chinese children, and to explore the possible risk factors affecting the different components of progression, as defined by Principal Component Analysis (PCA). A total of 637 first-born twins in Guangzhou Twin Eye Study with 6-year annual visits (baseline age 7–15 years) were available in the analysis. Cluster 1 to 3 were classified after a partitioning clustering, representing stable, slow and fast progressing groups of refraction respectively. Baseline age and refraction, paternal refraction, maternal refraction and proportion of two myopic parents showed significant differences across the three groups. Three major components of progression were extracted using PCA: “Average refraction”, “Acceleration” and the combination of “Myopia stabilization” and “Late onset of refraction progress”. In regression models, younger children with more severe myopia were associated with larger “Acceleration”. The risk factors of “Acceleration” included change of height and weight, near work, and parental myopia, while female gender, change of height and weight were associated with “Stabilization”, and increased outdoor time was related to “Late onset of refraction progress”. We therefore concluded that genetic and environmental risk factors have different impacts on patterns of refraction progression. PMID:27874105

Refractive Errors and Concomitant Strabismus: A Systematic Review and Meta-analysis.

PubMed

Tang, Shu Min; Chan, Rachel Y T; Bin Lin, Shi; Rong, Shi Song; Lau, Henry H W; Lau, Winnie W Y; Yip, Wilson W K; Chen, Li Jia; Ko, Simon T C; Yam, Jason C S

2016-10-12

This systematic review and meta-analysis is to evaluate the risk of development of concomitant strabismus due to refractive errors. Eligible studies published from 1946 to April 1, 2016 were identified from MEDLINE and EMBASE that evaluated any kinds of refractive errors (myopia, hyperopia, astigmatism and anisometropia) as an independent factor for concomitant exotropia and concomitant esotropia. Totally 5065 published records were retrieved for screening, 157 of them eligible for detailed evaluation. Finally 7 population-based studies involving 23,541 study subjects met our criteria for meta-analysis. The combined OR showed that myopia was a risk factor for exotropia (OR: 5.23, P = 0.0001). We found hyperopia had a dose-related effect for esotropia (OR for a spherical equivalent [SE] of 2-3 diopters [D]: 10.16, P = 0.01; OR for an SE of 3-4D: 17.83, P < 0.0001; OR for an SE of 4-5D: 41.01, P < 0.0001; OR for an SE of ≥5D: 162.68, P < 0.0001). Sensitivity analysis indicated our results were robust. Results of this study confirmed myopia as a risk for concomitant exotropia and identified a dose-related effect for hyperopia as a risk of concomitant esotropia.

Refractive Errors and Concomitant Strabismus: A Systematic Review and Meta-analysis

PubMed Central

Tang, Shu Min; Chan, Rachel Y. T.; Bin Lin, Shi; Rong, Shi Song; Lau, Henry H. W.; Lau, Winnie W. Y.; Yip, Wilson W. K.; Chen, Li Jia; Ko, Simon T. C.; Yam, Jason C. S.

2016-01-01

This systematic review and meta-analysis is to evaluate the risk of development of concomitant strabismus due to refractive errors. Eligible studies published from 1946 to April 1, 2016 were identified from MEDLINE and EMBASE that evaluated any kinds of refractive errors (myopia, hyperopia, astigmatism and anisometropia) as an independent factor for concomitant exotropia and concomitant esotropia. Totally 5065 published records were retrieved for screening, 157 of them eligible for detailed evaluation. Finally 7 population-based studies involving 23,541 study subjects met our criteria for meta-analysis. The combined OR showed that myopia was a risk factor for exotropia (OR: 5.23, P = 0.0001). We found hyperopia had a dose-related effect for esotropia (OR for a spherical equivalent [SE] of 2–3 diopters [D]: 10.16, P = 0.01; OR for an SE of 3-4D: 17.83, P < 0.0001; OR for an SE of 4-5D: 41.01, P < 0.0001; OR for an SE of ≥5D: 162.68, P < 0.0001). Sensitivity analysis indicated our results were robust. Results of this study confirmed myopia as a risk for concomitant exotropia and identified a dose-related effect for hyperopia as a risk of concomitant esotropia. PMID:27731389

[Comparative evaluation of the effectiveness of various treatment modalities for accommodation disorders and acquired progressive myopia].

PubMed

Tarutta, E P; Tarasova, N A

2015-01-01

To evaluate the effectiveness of non-surgical treatment of accommodation disorders and progressive myopia in children. A total of 190 patients (380 eyes) with myopia aged from 6 to 18 years (10.79±0.18 years on average) were enrolled and divided into 9 groups depending on the treatment prescribed. Comparative evaluation of different hardware-based treatment modalities for progressive myopia allowed to work out their optimal combination: "Visotronic", "MACDEL 09", and magnetophoresis of Taufon 4%. Such courses, provided twice a year, were associated with optimization of accommodative response and 1.9-2.8 times reduction of the rate of myopia progression. On the contrary, pleoptic therapy showed a negative effect on accommodative tonus and the rate of progression of acquired myopia. Comparative evaluation of different hardware-based treatment modalities for progressive myopia and accommodation disorders allowed to work out their optimal combination: "Visotronic", "MACDEL 09" and magnetophoresis of Taufon 4%. This treatment, provided twice a year, allows to increase accommodative reserves and volume, improve objective accommodative response, and reduce accommodative hypertonus as well as the rate of myopia progression (1.9-2.8 times over a 1.5-year period). Under pleoptic therapy (specialized software, near field speckles, color pulse therapy, Ambliokor device), both accommodative tonus and the rate of myopia progression increased (1.3-1.5 and 1.6 times correspondingly).

Single-step transepithelial ASLA (SCHWIND) with mitomycin-C for the correction of high myopia: long term follow-up

PubMed Central

Aslanides, Ioannis M; Georgoudis, Panagiotis N; Selimis, Vasilis D; Mukherjee, Achyut N

2015-01-01

Purpose We wanted to compare the outcomes of single-step modified transepithelial photorefractive keratectomy (tPRK) termed a SCHWIND all surface laser ablation (ASLA) versus conventional alcohol-assisted photorefractive keratectomy (PRK) and laser-assisted in situ keratomileusis (LASIK) for the correction of higher myopia of 6.00 diopters (D) or more, in an area with high risk of haze due to high intensity of sunlight. Methods We used a prospective interventional cohort with matched retrospective control groups. Patients with >6 D myopia and <3.5 D of astigmatism were included. All treatments were performed with the SCHWIND Amaris system using aspheric ablation profiles. Mitomycin C was used in all PRK and ASLA cases. Outcomes were postoperative refraction, visual acuity, stability, and complications. The follow-up period was up to 12 months. Results In total, 101 eyes were included after exclusions. Mean preoperative spherical equivalent refraction was -7.9 D, -8.2 D, and -7.4 D in the ASLA (n=41), PRK (n=29), and LASIK (n=31) groups. Mean postoperative spherical equivalent at 12 months postoperatively was −0.1 (standard deviation [SD]: 0.34), −0.2 (SD: 0.59), and −0.08 (SD: 0.36) in the ASLA, PRK, and LASIK groups, with 91.4%, 85.7%, and 83.9% within 0.5 D of target, respectively. Refractive outcomes and regression at 12 months did not vary among groups (P>0.05). Mean logMAR (logarithm of the minimum angle of resolution) uncorrected distance visual acuity at 12 months was 0.00 (SD: 0.05), 0.06 (SD: 0.1), and 0.05 (SD: 0.09) in the ASLA, PRK, and LASIK groups, with significantly better vision in the tPRK group versus LASIK (P=0.01) and PRK (P=0.01) groups. Conclusion ASLA (SCHWIND) tPRK with mitomycin C for high myopia demonstrates comparable refractive outcomes to LASIK and PRK, with relatively favorable visual acuity outcomes. There was no increased incidence of haze in the ASLA group. PMID:25565766

Effectiveness of combined macular buckle under direct vision and vitrectomy with ILM peeling in refractory macular hole retinal detachment with extreme high axial myopia: a 24-month comparative study.

PubMed

Ma, Jin; Li, Honghui; Ding, Xiaohu; Tanumiharjo, Silvia; Lu, Lin

2017-10-01

To evaluate the efficacy of a combined macular buckle under direct vision and 23-gauge pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling in refractory macular hole retinal detachment (MHRD) with extreme high axial myopia. Prospective, randomised controlled study. The study included 98 eyes of 98 patients of MHRD with extreme high axial (>30 mm) myopia. Patients were randomly assigned to undergo PPV with ILM peeling (group 1, n=52) or PPV with ILM peeling combined with macular buckle under direct vision (group 2, n=46). Complete ocular examination included best-corrected visual acuity (BCVA) (LogMAR), applanation tonometry, optical biometry, slit-lamp biomicroscopy, colour fundus photography, ultrasound examination and optical coherence tomography at baseline and every follow-up visit. Initial retinal reattachment rate was significantly higher in group 2 than in group 1 at 12-month postoperatively (χ 2 test, p=0.020). Macular hole closure rate in group 2 was significantly higher than that in group 1 at 3, 12, 18 and 24 months postoperatively (Fisher's exact test, p<0.05). In initial retinal reattachment cases, the mean BCVA decreased significantly in group 2 than in group 1 at 3 months postoperatively (Wilcoxon matched pairs signed rank test, p=0.036), and had increased significantly in group 2 than in group 1 since 6 months postoperatively (Wilcoxon matched pairs signed rank test, p<0.05). Mean axial lengths in group 2 were significantly shorter than that of group 1 at each follow-up time point (Wilcoxon matched pairs signed rank test, p<0.05). Combined macular buckle under direct vision and PPV with ILM peeling is more effective in treatment of MHRD with extreme high axial (>30 mm) myopia. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Single-step transepithelial ASLA (SCHWIND) with mitomycin-C for the correction of high myopia: long term follow-up.

PubMed

Aslanides, Ioannis M; Georgoudis, Panagiotis N; Selimis, Vasilis D; Mukherjee, Achyut N

2015-01-01

We wanted to compare the outcomes of single-step modified transepithelial photorefractive keratectomy (tPRK) termed a SCHWIND all surface laser ablation (ASLA) versus conventional alcohol-assisted photorefractive keratectomy (PRK) and laser-assisted in situ keratomileusis (LASIK) for the correction of higher myopia of 6.00 diopters (D) or more, in an area with high risk of haze due to high intensity of sunlight. We used a prospective interventional cohort with matched retrospective control groups. Patients with >6 D myopia and <3.5 D of astigmatism were included. All treatments were performed with the SCHWIND Amaris system using aspheric ablation profiles. Mitomycin C was used in all PRK and ASLA cases. Outcomes were postoperative refraction, visual acuity, stability, and complications. The follow-up period was up to 12 months. In total, 101 eyes were included after exclusions. Mean preoperative spherical equivalent refraction was -7.9 D, -8.2 D, and -7.4 D in the ASLA (n=41), PRK (n=29), and LASIK (n=31) groups. Mean postoperative spherical equivalent at 12 months postoperatively was -0.1 (standard deviation [SD]: 0.34), -0.2 (SD: 0.59), and -0.08 (SD: 0.36) in the ASLA, PRK, and LASIK groups, with 91.4%, 85.7%, and 83.9% within 0.5 D of target, respectively. Refractive outcomes and regression at 12 months did not vary among groups (P>0.05). Mean logMAR (logarithm of the minimum angle of resolution) uncorrected distance visual acuity at 12 months was 0.00 (SD: 0.05), 0.06 (SD: 0.1), and 0.05 (SD: 0.09) in the ASLA, PRK, and LASIK groups, with significantly better vision in the tPRK group versus LASIK (P=0.01) and PRK (P=0.01) groups. ASLA (SCHWIND) tPRK with mitomycin C for high myopia demonstrates comparable refractive outcomes to LASIK and PRK, with relatively favorable visual acuity outcomes. There was no increased incidence of haze in the ASLA group.

Laser-assisted in-situ keratomileusis (LASIK) versus photorefractive keratectomy (PRK) for myopia.

PubMed

Shortt, Alex J; Allan, Bruce D S; Evans, Jennifer R

2013-01-31

Myopia (also known as short-sightedness or near-sightedness) is an ocular condition in which the refractive power of the eye is greater than is required, resulting in light from distant objects being focused in front of the retina instead of directly on it. The two most commonly used surgical techniques to permanently correct myopia are photorefractive keratectomy (PRK) and laser-assisted in-situ keratomileusis (LASIK). To compare the effectiveness and safety of LASIK and PRK for correction of myopia by examining post-treatment uncorrected visual acuity, refractive outcome, loss of best spectacle-corrected visual acuity, pain scores, flap complications in LASIK, subepithelial haze, adverse events, quality of life indices and higher order aberrations. We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 11), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to November 2012), EMBASE (January 1980 to November 2012), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to November 2012), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 15 November 2012. We also searched the reference lists of the studies and the Science Citation Index. We included randomised controlled trials comparing LASIK and PRK for the correction of any degree of myopia. Two authors independently assessed trial quality and extracted data. We summarised data using the odds ratio and mean difference. We combined odds ratios using a random-effects model after testing for heterogeneity. We included 13 trials (1135 participants, 1923 eyes) in this review. Nine of these trials randomised eyes to treatment, two trials randomised people to treatment and treated both eyes, and two trials randomised people to treatment and treated one eye. None of the paired trials reported an appropriate paired analysis. We considered the overall quality of evidence to be low for most outcomes because of the risk of bias in the included trials. There was evidence that LASIK gives a faster visual recovery than PRK and is a less painful technique. Results at one year after surgery were comparable: most analyses favoured LASIK but they were not statistically significant. LASIK gives a faster visual recovery and is a less painful technique than PRK. The two techniques appear to give similar outcomes one year after surgery. Further trials using contemporary techniques are required to determine whether LASIK and PRK as currently practised are equally safe. Randomising eyes to treatment is an efficient design, but only if analysed properly. In future trials, more efforts could be made to mask the assessment of outcome.

The prevalence of refractive errors in 6- to 15-year-old schoolchildren in Dezful, Iran.

PubMed

Norouzirad, Reza; Hashemi, Hassan; Yekta, Abbasali; Nirouzad, Fereidon; Ostadimoghaddam, Hadi; Yazdani, Negareh; Dadbin, Nooshin; Javaherforoushzadeh, Ali; Khabazkhoob, Mehdi

2015-01-01

To determine the prevalence of refractive errors, among 6- to 15-year-old schoolchildren in the city of Dezful in western Iran. In this cross-sectional study, 1375 Dezful schoolchildren were selected through multistage cluster sampling. After obtaining written consent, participants had uncorrected and corrected visual acuity tests and cycloplegic refraction at the school site. Refractive errors were defined as myopia [spherical equivalent (SE) -0.5 diopter (D)], hyperopia (SE ≥ 2.0D), and astigmatism (cylinder error > 0.5D). 1151 (83.7%) schoolchildren participated in the study. Of these, 1130 completed their examinations. 21 individuals were excluded because of poor cooperation and contraindication for cycloplegic refraction. Prevalence of myopia, hyperopia, and astigmatism were 14.9% (95% confidence interval (CI): 10.1-19.6), 12.9% (95% CI: 7.2-18.6), and 45.3% (95% CI: 40.3-50.3), respectively. Multiple logistic regression analysis showed an age-related increase in myopia prevalence (p < 0.001) and a decrease in hyperopia prevalence (p < 0.001). There was a higher prevalence of myopia in boys (p<0.001) and hyperopia in girls (p = 0.007). This study showed a considerably high prevalence of refractive errors among the Iranian population of schoolchildren in Dezful in the west of Iran. The prevalence of myopia is considerably high compared to previous studies in Iran and increases with age.

Characteristics of Refractive Errors in a Population of Adults in the Central Region of Poland

PubMed Central

Jurowski, Piotr; Grzybowski, Andrzej; Smigielski, Janusz

2018-01-01

Background: To investigate the distribution of refractive errors and their characteristics in older adults from a Polish population. Methods: The study design was a cross-sectional study. A total of 1107 men and women were interviewed and underwent detailed ophthalmic examinations, 998 subjects underwent refraction. Myopia was defined as spherical equivalent (SER) refraction ≤−0.5 dioptres (D) and hyperopia was defined as SER ≥+0.5 dioptres (D). Results: Among those who were refracted the distribution of myopia and hyperopia was 24.1% (95% CI 21.4–26.7) and 37.5% (95% CI 34.5–40.5), respectively. Myopia decreased from 28.7% in subjects aged 35–59 years to 19.3% in those aged 60 years or older and hyperopia increased from 21.8% at 35–59 years of age to 53.3% in subjects aged ≥60 years. Multiple regression analysis showed decreasing age (OR 0.98, 95% CI 0.96–1.00), female gender (OR 1.87, 95% CI 1.18–2.95) and presence of cataract (OR 2.40, 95% CI 1.24–4.63) were independent risk factors associated with myopia. Conclusions: The distribution of refractive errors found in our study is similar to those reported in other Caucasian populations and differs from Asian populations. Myopia was positively associated with younger age, female gender and presence of cataract. PMID:29316688

Education and myopia in 110,236 young Singaporean males.

PubMed

Au Eong, K G; Tay, T H; Lim, M K

1993-12-01

Computerised data of 110,236 Singaporean males aged 15 to 25 (mean 17.75) years who underwent compulsory medical examination from April 1987 to January 1992 were used to estimate the prevalence and severity of myopia among young Chinese, Malay, Indian and Eurasian Singaporean males with different educational levels. The prevalence and severity of myopia amongst the groups with different educational levels were compared. These groups were fairly well-matched for important known confounding factors such as age, sex, race and degree of urbanisation of place of residence. Our data showed a positive association between educational attainment and both the prevalence and severity of myopia. Both the prevalence of myopia and the proportion of myopes with severe myopia were in general higher among those with more years of formal education.

The Dynamic Sclera: Extracellular Matrix Remodeling in Normal Ocular Growth and Myopia Development

PubMed Central

Harper, Angelica R.; Summers, Jody A.

2014-01-01

Myopia is a common ocular condition, characterized by excessive elongation of the ocular globe. The prevalence of myopia continues to increase, particularly among highly educated groups, now exceeding 80% in some groups. In parallel with the increased prevalence of myopia, are increases in associated blinding ocular conditions including glaucoma, retinal detachment and macular degeneration, making myopia a significant global health concern. The elongation of the eye is closely related to the biomechanical properties of the sclera, which in turn are largely dependent on the composition of the scleral extracellular matrix. Therefore an understanding of the cellular and extracellular events involved in the regulation of scleral growth and remodeling during childhood and young adulthood will provide future avenues for the treatment of myopia and its associated ocular complications. PMID:25819458

Meta-analysis of gene-environment-wide association scans accounting for education level identifies additional loci for refractive error.

PubMed

Fan, Qiao; Verhoeven, Virginie J M; Wojciechowski, Robert; Barathi, Veluchamy A; Hysi, Pirro G; Guggenheim, Jeremy A; Höhn, René; Vitart, Veronique; Khawaja, Anthony P; Yamashiro, Kenji; Hosseini, S Mohsen; Lehtimäki, Terho; Lu, Yi; Haller, Toomas; Xie, Jing; Delcourt, Cécile; Pirastu, Mario; Wedenoja, Juho; Gharahkhani, Puya; Venturini, Cristina; Miyake, Masahiro; Hewitt, Alex W; Guo, Xiaobo; Mazur, Johanna; Huffman, Jenifer E; Williams, Katie M; Polasek, Ozren; Campbell, Harry; Rudan, Igor; Vatavuk, Zoran; Wilson, James F; Joshi, Peter K; McMahon, George; St Pourcain, Beate; Evans, David M; Simpson, Claire L; Schwantes-An, Tae-Hwi; Igo, Robert P; Mirshahi, Alireza; Cougnard-Gregoire, Audrey; Bellenguez, Céline; Blettner, Maria; Raitakari, Olli; Kähönen, Mika; Seppala, Ilkka; Zeller, Tanja; Meitinger, Thomas; Ried, Janina S; Gieger, Christian; Portas, Laura; van Leeuwen, Elisabeth M; Amin, Najaf; Uitterlinden, André G; Rivadeneira, Fernando; Hofman, Albert; Vingerling, Johannes R; Wang, Ya Xing; Wang, Xu; Tai-Hui Boh, Eileen; Ikram, M Kamran; Sabanayagam, Charumathi; Gupta, Preeti; Tan, Vincent; Zhou, Lei; Ho, Candice E H; Lim, Wan'e; Beuerman, Roger W; Siantar, Rosalynn; Tai, E-Shyong; Vithana, Eranga; Mihailov, Evelin; Khor, Chiea-Chuen; Hayward, Caroline; Luben, Robert N; Foster, Paul J; Klein, Barbara E K; Klein, Ronald; Wong, Hoi-Suen; Mitchell, Paul; Metspalu, Andres; Aung, Tin; Young, Terri L; He, Mingguang; Pärssinen, Olavi; van Duijn, Cornelia M; Jin Wang, Jie; Williams, Cathy; Jonas, Jost B; Teo, Yik-Ying; Mackey, David A; Oexle, Konrad; Yoshimura, Nagahisa; Paterson, Andrew D; Pfeiffer, Norbert; Wong, Tien-Yin; Baird, Paul N; Stambolian, Dwight; Wilson, Joan E Bailey; Cheng, Ching-Yu; Hammond, Christopher J; Klaver, Caroline C W; Saw, Seang-Mei; Rahi, Jugnoo S; Korobelnik, Jean-François; Kemp, John P; Timpson, Nicholas J; Smith, George Davey; Craig, Jamie E; Burdon, Kathryn P; Fogarty, Rhys D; Iyengar, Sudha K; Chew, Emily; Janmahasatian, Sarayut; Martin, Nicholas G; MacGregor, Stuart; Xu, Liang; Schache, Maria; Nangia, Vinay; Panda-Jonas, Songhomitra; Wright, Alan F; Fondran, Jeremy R; Lass, Jonathan H; Feng, Sheng; Zhao, Jing Hua; Khaw, Kay-Tee; Wareham, Nick J; Rantanen, Taina; Kaprio, Jaakko; Pang, Chi Pui; Chen, Li Jia; Tam, Pancy O; Jhanji, Vishal; Young, Alvin L; Döring, Angela; Raffel, Leslie J; Cotch, Mary-Frances; Li, Xiaohui; Yip, Shea Ping; Yap, Maurice K H; Biino, Ginevra; Vaccargiu, Simona; Fossarello, Maurizio; Fleck, Brian; Yazar, Seyhan; Tideman, Jan Willem L; Tedja, Milly; Deangelis, Margaret M; Morrison, Margaux; Farrer, Lindsay; Zhou, Xiangtian; Chen, Wei; Mizuki, Nobuhisa; Meguro, Akira; Mäkelä, Kari Matti

2016-03-29

Myopia is the most common human eye disorder and it results from complex genetic and environmental causes. The rapidly increasing prevalence of myopia poses a major public health challenge. Here, the CREAM consortium performs a joint meta-analysis to test single-nucleotide polymorphism (SNP) main effects and SNP × education interaction effects on refractive error in 40,036 adults from 25 studies of European ancestry and 10,315 adults from 9 studies of Asian ancestry. In European ancestry individuals, we identify six novel loci (FAM150B-ACP1, LINC00340, FBN1, DIS3L-MAP2K1, ARID2-SNAT1 and SLC14A2) associated with refractive error. In Asian populations, three genome-wide significant loci AREG, GABRR1 and PDE10A also exhibit strong interactions with education (P<8.5 × 10(-5)), whereas the interactions are less evident in Europeans. The discovery of these loci represents an important advance in understanding how gene and environment interactions contribute to the heterogeneity of myopia.

Meta-analysis of gene–environment-wide association scans accounting for education level identifies additional loci for refractive error

PubMed Central

Fan, Qiao; Verhoeven, Virginie J. M.; Wojciechowski, Robert; Barathi, Veluchamy A.; Hysi, Pirro G.; Guggenheim, Jeremy A.; Höhn, René; Vitart, Veronique; Khawaja, Anthony P.; Yamashiro, Kenji; Hosseini, S Mohsen; Lehtimäki, Terho; Lu, Yi; Haller, Toomas; Xie, Jing; Delcourt, Cécile; Pirastu, Mario; Wedenoja, Juho; Gharahkhani, Puya; Venturini, Cristina; Miyake, Masahiro; Hewitt, Alex W.; Guo, Xiaobo; Mazur, Johanna; Huffman, Jenifer E.; Williams, Katie M.; Polasek, Ozren; Campbell, Harry; Rudan, Igor; Vatavuk, Zoran; Wilson, James F.; Joshi, Peter K.; McMahon, George; St Pourcain, Beate; Evans, David M.; Simpson, Claire L.; Schwantes-An, Tae-Hwi; Igo, Robert P.; Mirshahi, Alireza; Cougnard-Gregoire, Audrey; Bellenguez, Céline; Blettner, Maria; Raitakari, Olli; Kähönen, Mika; Seppala, Ilkka; Zeller, Tanja; Meitinger, Thomas; Ried, Janina S.; Gieger, Christian; Portas, Laura; van Leeuwen, Elisabeth M.; Amin, Najaf; Uitterlinden, André G.; Rivadeneira, Fernando; Hofman, Albert; Vingerling, Johannes R.; Wang, Ya Xing; Wang, Xu; Tai-Hui Boh, Eileen; Ikram, M. Kamran; Sabanayagam, Charumathi; Gupta, Preeti; Tan, Vincent; Zhou, Lei; Ho, Candice E. H.; Lim, Wan'e; Beuerman, Roger W.; Siantar, Rosalynn; Tai, E-Shyong; Vithana, Eranga; Mihailov, Evelin; Khor, Chiea-Chuen; Hayward, Caroline; Luben, Robert N.; Foster, Paul J.; Klein, Barbara E. K.; Klein, Ronald; Wong, Hoi-Suen; Mitchell, Paul; Metspalu, Andres; Aung, Tin; Young, Terri L.; He, Mingguang; Pärssinen, Olavi; van Duijn, Cornelia M.; Jin Wang, Jie; Williams, Cathy; Jonas, Jost B.; Teo, Yik-Ying; Mackey, David A.; Oexle, Konrad; Yoshimura, Nagahisa; Paterson, Andrew D.; Pfeiffer, Norbert; Wong, Tien-Yin; Baird, Paul N.; Stambolian, Dwight; Wilson, Joan E. Bailey; Cheng, Ching-Yu; Hammond, Christopher J.; Klaver, Caroline C. W.; Saw, Seang-Mei; Rahi, Jugnoo S.; Korobelnik, Jean-François; Kemp, John P.; Timpson, Nicholas J.; Smith, George Davey; Craig, Jamie E.; Burdon, Kathryn P.; Fogarty, Rhys D.; Iyengar, Sudha K.; Chew, Emily; Janmahasatian, Sarayut; Martin, Nicholas G.; MacGregor, Stuart; Xu, Liang; Schache, Maria; Nangia, Vinay; Panda-Jonas, Songhomitra; Wright, Alan F.; Fondran, Jeremy R.; Lass, Jonathan H.; Feng, Sheng; Zhao, Jing Hua; Khaw, Kay-Tee; Wareham, Nick J.; Rantanen, Taina; Kaprio, Jaakko; Pang, Chi Pui; Chen, Li Jia; Tam, Pancy O.; Jhanji, Vishal; Young, Alvin L.; Döring, Angela; Raffel, Leslie J.; Cotch, Mary-Frances; Li, Xiaohui; Yip, Shea Ping; Yap, Maurice K.H.; Biino, Ginevra; Vaccargiu, Simona; Fossarello, Maurizio; Fleck, Brian; Yazar, Seyhan; Tideman, Jan Willem L.; Tedja, Milly; Deangelis, Margaret M.; Morrison, Margaux; Farrer, Lindsay; Zhou, Xiangtian; Chen, Wei; Mizuki, Nobuhisa; Meguro, Akira; Mäkelä, Kari Matti

2016-01-01

Myopia is the most common human eye disorder and it results from complex genetic and environmental causes. The rapidly increasing prevalence of myopia poses a major public health challenge. Here, the CREAM consortium performs a joint meta-analysis to test single-nucleotide polymorphism (SNP) main effects and SNP × education interaction effects on refractive error in 40,036 adults from 25 studies of European ancestry and 10,315 adults from 9 studies of Asian ancestry. In European ancestry individuals, we identify six novel loci (FAM150B-ACP1, LINC00340, FBN1, DIS3L-MAP2K1, ARID2-SNAT1 and SLC14A2) associated with refractive error. In Asian populations, three genome-wide significant loci AREG, GABRR1 and PDE10A also exhibit strong interactions with education (P<8.5 × 10−5), whereas the interactions are less evident in Europeans. The discovery of these loci represents an important advance in understanding how gene and environment interactions contribute to the heterogeneity of myopia. PMID:27020472

Insulin acts as a powerful stimulator of axial myopia in chicks.

PubMed

Feldkaemper, Marita P; Neacsu, Irina; Schaeffel, Frank

2009-01-01

In animal models, it has been shown that the retina can use the defocus of the projected image to control emmetropization. Glucagon may be involved in the sign of defocus detection, at least in chickens. Since glucagon and insulin often have opposite effects in metabolic pathways, the effect of insulin on eye growth was investigated. Chicks were treated with either positive or negative spectacle lenses and intravitreally injected with saline or different amounts of insulin. Refraction, axial length, and corneal curvature were measured. Effects of insulin on vitreal glucose concentration, on retinal ZENK and glucagon mRNA levels, and on the number of ZENK-immunoreactive glucagon amacrine cells were studied. Insulin injections (0.3 nmol) caused only a small myopic shift in control chicks. When positive lenses were worn, insulin injections (0.3; 0.03 nmol) not only blocked hyperopia but rather induced high amounts of axial myopia. Insulin also enhanced myopia that was induced by negative lenses. Axial elongation was mostly due to an increase in anterior chamber depth and a thickening of the crystalline lens. Insulin temporarily reduced vitreal glucose levels. Insulin increased retinal ZENK mRNA levels, whereas the number of ZENK-immunoreactive glucagon amacrine cells was reduced, a finding that is typically linked to the development of myopia. Given that insulin is used in therapy for human metabolic disorders and has been proposed to treat corneal epithelial disease, its powerful myopiagenic effect, which is mostly due to its effects on the optics of the anterior segment of the eye, merits further investigation.

Risk factors for incident myopia in Australian schoolchildren: the Sydney adolescent vascular and eye study.

PubMed

French, Amanda N; Morgan, Ian G; Mitchell, Paul; Rose, Kathryn A

2013-10-01

To examine the risk factors for incident myopia in Australian schoolchildren. Population-based, longitudinal cohort study. The Sydney Adolescent Vascular and Eye Study (SAVES) was a 5- to 6-year follow-up of the Sydney Myopia Study (SMS). At follow-up, 2103 children were reexamined: 892 (50.5%) from the younger cohort and 1211 (51.5%) from the older cohort. Of these, 863 in the younger cohort and 1196 in the older cohort had complete refraction data. Cycloplegic autorefraction (cyclopentolate 1%; Canon RK-F1; Canon, Tokyo, Japan) was measured at baseline and follow-up. Myopia was defined as a spherical equivalent refraction of ≤-0.50 diopters (D). Children were classified as having incident myopia if they were nonmyopic at baseline and myopic in either eye at follow-up. A comprehensive questionnaire determined the amount of time children spent outdoors and doing near work per week at baseline, as well as ethnicity, parental myopia, and socioeconomic status. Incident myopia. Children who became myopic spent less time outdoors compared with children who remained nonmyopic (younger cohort, 16.3 vs. 21.0 hours, respectively, P<0.0001; older cohort, 17.2 vs. 19.6 hours, respectively, P=0.001). Children who became myopic performed significantly more near work (19.4 vs. 17.6 hours; P=0.02) in the younger cohort, but not in the older cohort (P=0.06). Children with 1 or 2 parents who were myopic had greater odds of incident myopia (1 parent: odds ratio [OR], 3.2, 95% confidence interval [CI], 1.9-5.2; both parents: OR, 3.3, 95% CI, 1.6-6.8) in the younger but not the older cohort. Children of East Asian ethnicity had a higher incidence of myopia compared with children of European Caucasian ethnicity (both P<0.0001) and spent less time outdoors (both P<0.0001). A less hyperopic refraction at baseline was the most significant predictor of incident myopia. The addition of time outdoors, near work, parental myopia, and ethnicity to the model significantly improved the predictive power (P<0.0001) in the younger cohort but had little effect in the older cohort. Time spent outdoors was negatively associated with incident myopia in both age cohorts. Near work and parental myopia were additional significant risk factors for myopia only in the younger cohort. The author(s) have no proprietary or commercial interest in any materials discussed in this article. Copyright © 2013 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Education-Related Parameters in High Myopia: Adults versus School Children

PubMed Central

Xu, Liang; Wang, Ya Xing; Bi, Hong Sheng; Wu, Jian Feng; Jiang, Wen Jun; Nangia, Vinay; Sinha, Ajit; Zhu, Dan; Tao, Yong; Guo, Yin; You, Qi Sheng; Wu, Li Juan; Tao, Li Xin; Guo, Xiu Hua; Ohno-Matsui, Kyoko; Panda-Jonas, Songhomitra

2016-01-01

Purpose Since high myopia in the younger generation may differ etiologically from high myopia in older generations, we examined whether education-related parameters differ between high myopia in today´s school children and high pathological myopia in today´s elderly generation. Methods The investigation included the adult populations of the population-based Beijing Eye Study (BES) (3468 adults;mean age:64.6±9.8years;range:50–93years) and Central India Eye and Medical Study (CIEMS) (4711 adults;age:49.±13.2years;range:30–100years), and the children and teenager populations of the Shandong Children Eye Study (SCES) (6026 children;age:9.7±3.3years;range:4–18years;cycloplegic refractometry), Gobi Desert Children Eye Study (1565;age:11.9±3.5years;range:6–21 years;cycloplegic refractometry), Beijing Pediatric Eye Study (681 children;age:7.7±1.6years;range:5–13 years;non-cycloplegic refractometry,calculation of axial length to corneal curvature radius ratio), Beijing Children Eye Study (15066 children;age:13.2±3.4years;range:7–18years;non-cycloplegic refractometry), Beijing High School Teenager Eye Study (4677 children;age:16.9±0.7years;range:16–18years;non-cycloplegic refractometry). Results In the BES and CIEMS, educational level did not differ significantly between, or was significantly lower in the highly myopic group (myopic refractive error ≥6 diopters) than in the non-highly myopic group. In all non-adult study populations, higher prevalence of high myopia was significantly associated with higher degree of education related parameters such as attendance of high-level schools, and more time spent for indoors near work versus time spent outdoors. Conclusions Comparing associations of old or genetic high myopia in adults with new or acquired high myopia in school children revealed that education-related parameters did not show a clear association with old or genetic high myopia, while in contrast, new high myopia showed strong associations with education. It confirms previous studies that the two forms of high myopia not only differed in age of onset, but also in associations with education as well. The data support the notion of two types of high myopia. Future studies may assess whether the risk of pathologic myopic maculopathy and high myopia associated open-angle glaucoma differs between both types of high myopia. PMID:27152764

Effects of atropine on refractive development, dopamine release, and slow retinal potentials in the chick.

PubMed

Schwahn, H N; Kaymak, H; Schaeffel, F

2000-01-01

Atropine has previously been found to suppress visually induced myopia both in animals and humans. The mechanism of its action is unclear. We have studied its retinal effects in an in vitro preparation, using the retina-pigment epithelium-choroid complex of the chick eye. In vivo, deprivation myopia was induced by translucent goggles. Atropine solution was injected into the vitreous at two-day intervals. Dopamine release from the retina following atropine injection in vivo and from the in vitro retina preparation was quantified by HPLC-EC. In vitro preparations of the isolated chick retina-pigment epithelium-choroid were superfused with atropine. Light-induced potentials (local ERG), slow standing potentials from the retinal pigment epithelium/neural retina, and extracellular potassium concentrations were recorded. In line with previous findings, intravitreal injections of atropine (25 microg, 250 microg) reduced deprivation myopia in a dose-dependent manner. Atropine increased the release of the neurotransmitter dopamine into the superfusate in vitro at 100-500 microM and into the vitreous in vivo at 250 microg. Before an increase was measured in the vitreous, the retinal dopamine content was elevated. In concentrations equivalent to the intravitreal concentration to suppress myopia in vivo (200-800 microM), atropine induced spreading depression (SD) in the in vitro preparation. In contrast, muscarinic agonists, acetylcholine and pilocarpine, did not induce SD. Atropine reduced the ERG b- and d-wave, led to damped oscillations of RPE potentials, and reversed the ERG c-wave. Atropine suppressed myopia only at doses at which severe nonspecific side effects were observed in the retina. Atropine seems to intrude massively into the vital functions of the retina as indicated by the occurrence of SD. We conclude that atropine, by inducing SD, boosts neurotransmitter release from cellular stores, which may cancel out a presumed retinal signal that controls eye growth and through this, myopia.

Effectiveness study of atropine for progressive myopia in Europeans.

PubMed

Polling, J R; Kok, R G W; Tideman, J W L; Meskat, B; Klaver, C C W

2016-07-01

PurposeRandomized controlled trials have shown the efficacy of atropine for progressive myopia, and this treatment has become the preferred pattern for this condition in Taiwan. This study explores the effectiveness of atropine 0.5% treatment for progressive high myopia and adherence to therapy in a non-Asian country.MethodsAn effectiveness study was performed in Rotterdam, the Netherlands. Overall 77 children (mean age 10.3 years±2.3), of European (n=53), Asian (n=18), and African (n=6) descent with progressive myopia were prescribed atropine 0.5% eye drops daily. Both parents and children filled in a questionnaire regarding adverse events and adherence to therapy. A standardized eye examination including cycloplegic refraction and axial length was performed at baseline and 1, 4, and 12 months after initiation of therapy.ResultsMean spherical equivalent at baseline was -6.6D (±3.3). The majority (60/77, 78%) of children adhered to atropine treatment for 12 months; 11 of the 17 children who discontinued therapy did so within 1 month after the start of therapy. The most prominent reported adverse events were photophobia (72%), followed by reading problems (38%), and headaches (22%). The progression rate of spherical equivalent before treatment (-1.0D/year±0.7) diminished substantially during treatment (-0.1D/year±0.7) compared to those who ceased therapy (-0.5D/year±0.6; P=0.03).ConclusionsDespite the relatively high occurrence of adverse events, our study shows that atropine can be an effective and sustainable treatment for progressive high myopia in Europeans.

Total ocular, anterior corneal and lenticular higher order aberrations in hyperopic, myopic and emmetropic eyes.

PubMed

Philip, Krupa; Martinez, Aldo; Ho, Arthur; Conrad, Fabian; Ale, Jit; Mitchell, Paul; Sankaridurg, Padmaja

2012-01-01

Total ocular higher order aberrations and corneal topography of myopic, emmetropic and hyperopic eyes of 675 adolescents (16.9 ± 0.7 years) were measured after cycloplegia using COAS aberrometer and Medmont videokeratoscope. Corneal higher order aberrations were computed from the corneal topography maps and lenticular (internal) higher order aberrations derived by subtraction of corneal aberrations from total ocular aberrations. Aberrations were measured for a pupil diameter of 5mm. Multivariate analysis of variance followed by multiple regression analysis found significant difference in the fourth order aberrations (SA RMS, primary spherical aberration coefficient) between the refractive error groups. Hyperopic eyes (+0.083 ± 0.05 μm) had more positive total ocular primary spherical aberration compared to emmetropic (+0.036 ± 0.04 μm) and myopic eyes (low myopia=+0.038 ± 0.05 μm, moderate myopia=+0.026 ± 0.06 μm) (p<0.05). No difference was observed for the anterior corneal spherical aberration. Significantly less negative lenticular spherical aberration was observed for the hyperopic eyes (-0.038 ± 0.05 μm) than myopic (low myopia=-0.088 ± 0.04 μm, moderate myopia=-0.095 ± 0.05 μm) and emmetropic eyes (-0.081 ± 0.04 μm) (p<0.05). These findings suggest the existence of differences in the characteristics of the crystalline lens (asphericity, curvature and gradient refractive index) of hyperopic eyes versus other eyes. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

Prevalence of macular complications associated with high myopia by multimodal imaging.

PubMed

Lichtwitz, O; Boissonnot, M; Mercié, M; Ingrand, P; Leveziel, N

2016-04-01

To describe the prevalence of macular complications in patients with visual acuity decrease related to high myopia (HM). To establish correlations between these complications and demographic or anatomical characteristics. Cross-sectional observational study including HM patients undergoing best-corrected visual acuity (BCVA), fundus examination, macular SD-OCT, and fluorescein angiography in the case of suspicion of choroidal neovascularization (CNV). The presence of anatomical criteria (staphyloma, subfoveal choroidal thickness [CT]) and macular complications (CNV, lacquer cracks, central chorioretinal atrophy, dome-shaped macula with serous retinal detachment [SRD], retinal foveoschisis, macular hole and epiretinal membrane) was investigated. A total of 87 eyes of 47 patients were included (39 eyes without macular complication and 48 eyes with macular complications). In the case of macular complications, decrease in BCVA was related to CNV in 33%, macular hole in 25%, chorioretinal atrophy in 19%, foveoschisis in 11%, lacquer crack in 6%, to a dome-shape macula with serous retinal detachment in 4% and epiretinal membrane in 2%. After adjusting for interocular correlation and degree of myopia, staphyloma (P=0.0023), choroidal thinning (P=0.0036), and extrafoveal chorioretinal atrophy (P=0.042) were significantly associated with macular complications. High myopic patients with staphyloma or choroidal thinning should undergo regular comprehensive retinal screening for retinal complications. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Single-Step Transepithelial PRK vs Alcohol-Assisted PRK in Myopia and Compound Myopic Astigmatism Correction.

PubMed

Kaluzny, Bartlomiej J; Cieslinska, Iwona; Mosquera, Samuel A; Verma, Shwetabh

2016-02-01

Transepithelial photorefractive keratectomy (tPRK), where both the epithelium and stroma are removed in a single-step, is a relatively new procedure of laser refractive error correction. This study compares the 3-month results of myopia and compound myopic astigmatism correction by tPRK or conventional alcohol-assisted PRK (aaPRK).This prospective, nonrandomized, case-control study recruited 148 consecutive patients; 93 underwent tPRK (173 eyes) and 55 aaPRK (103 eyes). Refractive results, predictability, safety, and efficacy were evaluated during the 3-month follow-up. The main outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and mean refractive spherical equivalent (MRSE).Mean preoperative MRSE was -4.30 ± 1.72 D and -4.33 ± 1.96 D, respectively (P = 0.87). The 3-month follow-up rate was 82.1% in the tPRK group (n = 145) and 86.4% in aaPRK group (n = 90), P = 0.81. Postoperative UDVA was 20/20 or better in 97% and 94% of eyes, respectively (P = 0.45). In the tPRK and aaPRK groups, respectively, 13% and 21% of eyes lost 1 line of CDVA, and 30% and 31% gained 1 or 2 lines (P = 0.48). Mean postoperative MRSE was -0.14 ± 0.26 D in the tPRK group and -0.12 ± 0.20 D in the aaPRK group (P = 0.9). The correlation between attempted versus achieved MRSE was equally high in both groups.Single-step transepithelial PRK and conventional PRK provide very similar results 3 months postoperatively. These procedures are predictable, effective, and safe for correction of myopia and compound myopic astigmatism.

Evaluation of a Myopic Normative Database for Analysis of Retinal Nerve Fiber Layer Thickness.

PubMed

Biswas, Sayantan; Lin, Chen; Leung, Christopher K S

2016-09-01

Analysis of retinal nerve fiber layer (RNFL) abnormalities with optical coherence tomography in eyes with high myopia has been complicated by high rates of false-positive errors. An understanding of whether the application of a myopic normative database can improve the specificity for detection of RNFL abnormalities in eyes with high myopia is relevant. To evaluate the diagnostic performance of a myopic normative database for detection of RNFL abnormalities in eyes with high myopia (spherical equivalent, -6.0 diopters [D] or less). In this cross-sectional study, 180 eyes with high myopia (mean [SD] spherical equivalent, -8.0 [1.8] D) from 180 healthy individuals were included in the myopic normative database. Another 46 eyes with high myopia from healthy individuals (mean [SD] spherical equivalent, -8.1 [1.8] D) and 74 eyes from patients with high myopia and glaucoma (mean [SD] spherical equivalent, -8.3 [1.9] D) were included for evaluation of specificity and sensitivity. The 95th and 99th percentiles of the mean and clock-hour circumpapillary RNFL thicknesses and the individual superpixel thicknesses of the RNFL thickness map measured by spectral-domain optical coherence tomography were calculated from the 180 eyes with high myopia. Participants were recruited from January 2, 2013, to December 30, 2015. The following 6 criteria of RNFL abnormalities were examined: (1) mean circumpapillary RNFL thickness below the lower 95th or (2) the lower 99th percentile; (3) one clock-hour or more for RNFL thickness below the lower 95th or (4) the lower 99th percentile; and (5) twenty contiguous superpixels or more of RNFL thickness in the RNFL thickness map below the lower 95th or (6) the lower 99th percentile. Specificities and sensitivities for detection of RNFL abnormalities. Of the 46 healthy eyes and 74 eyes with glaucoma studied (from 39 men and 38 women), the myopic normative database showed a higher specificity (63.0%-100%) than did the built-in normative database of the optical coherence tomography instrument (8.7%-87.0%) for detection of RNFL abnormalities across all the criteria examined (differences in specificities between 13.0% [95% CI, 1.1%-24.9%; P = .01] and 54.3% [95% CI, 37.8%-70.9%; P < .001]) except for the criterion of mean RNFL thickness below the lower 99th percentile, in which both normative databases had the same specificities (100%) but the myopic normative database exhibited a higher sensitivity (71.6% vs 86.5%; difference in sensitivities, 14.9% [95% CI, 4.6%-25.1%; P = .002]). The application of a myopic normative database improved the specificity without compromising the sensitivity compared with the optical coherence tomography instrument's built-in normative database for detection of RNFL abnormalities in eyes with high myopia. Inclusion of myopic normative databases should be considered in optical coherence tomography instruments.

An Ecologic Study of Trends in the Prevalence of Myopia in Chinese Adults in Singapore Born from the 1920s to 1980s.

PubMed

Sensaki, Sonoko; Sabanayagam, Charumathi; Verkicharla, Pavan K; Awodele, Adeola; Tan, Kok Hian; Chia, Audrey; Saw, Seang Mei

2017-06-01

This study aimed to investigate secular trends in the prevalence of myopia over 6 decades (from the 1920s to 1980s) in Chinese adults in Singapore. Parental myopia prevalence was estimated using a parent-completed questionnaire in paediatric cohorts that included: 1) The Singapore Cohort Of Risk factors for Myopia (SCORM), 2) The Strabismus, Amblyopia and Refractive Error in Singaporean Children (STARS), and 3) The Growing Up in Singapore Towards healthy Outcomes (GUSTO). Published estimates for myopia prevalence from 5 adult studies in Singapore were reviewed. Secular trends in the prevalence of myopia were correlated with changes in the education system. The prevalence of parental myopia in SCORM (n = 2943), STARS (n = 4938), and GUSTO (n = 1072) was 47.8%, 53.4%, and 73.4%, respectively; corresponding calendar years these parents might have started schooling were 1966, 1973, and 1983 (born in 1960, 1967, and 1977), respectively. Mean age of parents was 41.3, 40.1, and 33.4 years, respectively. Prevalence of myopia in adult studies in persons who started elementary school in 1928, 1934, 1938, 1939, 1942, 1948, 1952, 1958, 1962, 1972, 1982, and 1995 were 36.4%, 39.7%, 30.0%, 31.5%, 33.0%, 26.4%, 32.5%, 48.7%, 39.4%, 52.0%, 82.2%, and 85.9%, respectively. During the past few decades, the prevalence of myopia increased rapidly, especially in persons who started elementary school after the 1980s (born after 1970). The education system was expanded after Singapore's independence in 1965, and the new education system was introduced in 1978. These changes, together with increasing intensive schooling, may have contributed to the increase in myopia prevalence.

Visual Activity before and after the Onset of Juvenile Myopia

PubMed Central

Jones-Jordan, Lisa A.; Mitchell, G. Lynn; Cotter, Susan A.; Kleinstein, Robert N.; Manny, Ruth E.; Mutti, Donald O.; Twelker, J. Daniel; Sims, Janene R.

2011-01-01

Purpose. To investigate visual activities before and after the onset of juvenile myopia. Methods. The subjects were 731 incident myopes (−0.75 D or more myopia on cycloplegic autorefraction in both meridians) and 587 emmetropes (between −0.25 and +1.00 D) in the Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error (CLEERE) Study. Parents supplied visual activity data annually. Data from myopic children 5 years before through 5 years after myopia onset were compared to data from age-, sex-, and ethnicity-matched models of children who remained emmetropic. Results. Hours per week spent reading or using a computer/playing video games did not differ between the groups before myopia onset; however, hours per week for both activities were significantly greater in myopes than in emmetropes at onset and in 4 of the 5 years after onset by 0.7 to 1.6 hours per week. Hours per week spent in outdoor/sports activities were significantly fewer for children who became myopic 3 years before onset through 4 years after onset by 1.1 to 1.8 hours per week. Studying and TV watching were not significantly different before myopia onset. Conclusions. Before myopia onset, near work activities of future myopic children did not differ from those of emmetropes. Those who became myopic had fewer outdoor/sports activity hours than the emmetropes before, at, and after myopia onset. Myopia onset may influence children's near work behavior, but the lack of difference before onset argues against a major causative role for near work. Less outdoor/sports activity before myopia onset may exert a stronger influence on development than near work. PMID:20926821

Myopia and international educational performance.

PubMed

Morgan, Ian G; Rose, Kathryn A

2013-05-01

To analyse the relationship between myopia, educational performance and engagement in after-school tutorial classes. Educational performance data and data on engagement in after-school tutorial classes were taken from the results of the Organisation for Economic Cooperation and Development (OECD) Program in Secondary Assessment (PISA) reports for 2009, which tested educational outcomes in representative samples of 15 year-old school children from 65 jurisdictions. High prevalence of myopia (>70%) and low prevalence of myopia (<40%) locations were identified by systematic literature search. Six locations with a high prevalence of myopia were identified from among the participants in PISA 2009 - Shanghai-China, Hong Kong-China, Taiwan, Singapore, Japan and South Korea. All were ranked in the top quartile on educational performance. Other participants in the top educational performance quartile were identified as locations with a low prevalence of myopia, including Australia and Finland. The locations with a high prevalence of myopia combined high educational performance and high engagement in after-school tutorials, whereas the locations with a low prevalence of myopia combined high educational performance with little engagement in tutorials. These results show that it is possible to achieve high educational outcomes without extensive engagement in after-school tutorials, and that the combination of high educational outcomes with extensive use of tutorials is associated with high prevalence rates of myopia. We suggest that extensive use of after-school tutorials may be a marker of educational environments which impose high educational loads. Further quantification of educational loads to include after- school educational activities, such as homework, tutorials and other after-school classes, as well as formal school classes, is desirable. Policy initiatives to decrease these loads may contribute to the prevention of myopia, perhaps, at least in part, by enabling children to spend more time outdoors. Ophthalmic & Physiological Optics © 2013 The College of Optometrists.

Prevalence of refractive errors in a multiethnic Asian population: the Singapore epidemiology of eye disease study.

PubMed

Pan, Chen-Wei; Zheng, Ying-Feng; Anuar, Ainur Rahman; Chew, Merwyn; Gazzard, Gus; Aung, Tin; Cheng, Ching-Yu; Wong, Tien Y; Saw, Seang-Mei

2013-04-09

To determine the prevalence of refractive errors in a multiethnic Asian population aged over 40 years and to examine secular trends and racial differences. A total of 10,033 adults (3353 Chinese, 3400 Indians, and 3280 Malays) participated in this study. Refractive error was determined by subjective refraction. Ocular biometric parameters were determined by partial coherence interferometry. Myopia and high myopia were defined as spherical equivalent (SE) of less than -0.5 diopters (D) and -5.0 D, respectively. Hyperopia was defined as SE of more than 0.5 D. Astigmatism was defined as cylinders less than -0.5 D. The prevalence of myopia, high myopia, hyperopia and astigmatism in Singapore adults aged over 40 years was 38.9% (95% confidence interval [CI] 37.1, 40.6); 8.4% (95% CI 8.0, 8.9); 31.5% (95% 30.5, 32.5); and 58.8% (95% CI 57.8, 59.9), respectively. Compared with the Tanjong Pagar Survey 12 years ago, there was a significant increase in the prevalence of astigmatism and mean axial length (AL) in Chinese adults aged over 40 years in Singapore. Chinese were most likely to be affected by myopia, high myopia, astigmatism, and had the longest AL among the three racial groups. The prevalence of myopia in Singapore adults is lower compared with the younger "myopia" generation in Singapore. The prevalence of astigmatism and mean AL have been increasing significantly within the past 12 years in the Chinese population. Chinese adults had higher prevalence of myopia, high myopia, astigmatism, as well as the longer AL compared with non-Chinese adults in Singapore.

Prevalence and risk factors for refractive errors in the Singapore Malay Eye Survey.

PubMed

Saw, Seang-Mei; Chan, Yiong-Huak; Wong, Wan-Ling; Shankar, Anoop; Sandar, Mya; Aung, Tin; Tan, Donald T H; Mitchell, Paul; Wong, Tien Yin

2008-10-01

To describe the prevalence and risk factors for myopia and other refractive errors in an urban Malay population in Singapore. Population-based, cross-sectional study. Persons of Malay ethnicity, between 40 and 80 years of age, living in Singapore. Refractive error was determined by subjective refraction and if unavailable by autorefraction. Data were analyzed for 2974 adults without previous cataract surgery and who had right eye refraction data. Risk factor data, such as education levels and near work activity, were obtained from a face-to-face interview. Myopia, defined as spherical equivalent (SE) refraction less than -0.5 diopters (D), astigmatism as cylinder less than -0.5 D, hyperopia as SE greater than 0.5 D, and anisometropia as the difference in SE greater than 1.0 D. The prevalence of myopia in the right eye was 30.7% (9.4% unilateral myopia and 21.3% bilateral myopia), the prevalence of astigmatism in the right eye was 33.3% (95% confidence interval [CI, 33.0-33.5), the prevalence of hyperopia in the right eye was 27.4% (95% CI, 24.7-27.6), and the prevalence of anisometropia was 9.9% (95% CI, 9.7-10.0). There was a U-shaped relationship between increasing age and the prevalence of myopia, which was partially explained by the age-related increase in the prevalence of cataract. In a multiple logistic regression model, female sex, age, higher educational level, and cataract were associated with myopia. Adults with myopia were more likely to have astigmatism (P<0.001) in multivariate analyses. A quarter of older adult Malay people in Singapore had myopia. Compared with previous reports of similarly aged Singapore Chinese adults, the prevalence of myopia, astigmatism, and anisometropia was lower, whereas the prevalence of hyperopia was similar.

[Peripheral refraction and retinal contour in children with myopia by results of refractometry and partial coherence interferometry].

PubMed

Tarutta, E P; Milash, S V; Tarasova, N A; Romanova, L I; Markosian, G A; Epishina, M V

2014-01-01

To determine the posterior pole contour of the eye based on the relative peripheral refractive error and relative eye length. A parallel study was performed, which enrolled 38 children (76 eyes) with myopia from -1.25 to -10.82 diopters. The patients underwent peripheral refraction assessment with WR-5100K Binocular Auto Refractometer ("Grand Seiko", Japan) and partial coherence tomography with IOLMaster ("Carl Zeiss", Germany) for the relative eye length in areas located 15 and 30 degrees nasal and temporal from the central fovea along the horizontal meridian. In general, refractometry and interferometry showed high coincidence of defocus signs and values for the areas located 15 and 30 degrees nasal as well as 15 degrees temporal from the fovea. However, in 41% of patients defocus signs determined by the two methods mismatched in one or more areas. Most of the mismatch cases were mild myopia. We suppose that such a mismatch is caused by optical peculiarities of the anterior eye segment that have an impact on refractometry results.

A Novel Review of the Evidence Linking Myopia and High Intelligence

PubMed Central

Verma, Ajai; Verma, Abhishek

2015-01-01

The association between myopia and high intelligence has been the subject of much vexed debate in academic circles, particularly over the last two decades. This debate has risen from the observation that, over recent centuries, the prevalence of myopia amongst most populations has coincided with a marked increase in the average level of intelligence in these populations. The relationship between myopia and intelligence and theories surrounding this association is examined by the authors. Additionally, the various factors that confound the myopia and high intelligence debate, such as genetics, educational levels, ethnicity, and environmental factors were also explored by the authors. Whilst most studies found a positive correlation reaching statistical significance between myopia and high intelligence compared to emmetropes and hyperopes, further research is required to determine whether this association is causal. PMID:25653868

Impact of Myopia on Corneal Biomechanics in Glaucoma and Nonglaucoma Patients.

PubMed

Chansangpetch, Sunee; Panpruk, Rawiphan; Manassakorn, Anita; Tantisevi, Visanee; Rojanapongpun, Prin; Hurst, Cameron P; Lin, Shan C

2017-10-01

We evaluated the impact of myopia on corneal biomechanical properties in primary open-angle glaucoma (POAG) and nonglaucoma patients, and the effect of modification of glaucoma on myopic eyes. This cross-sectional study included 66 POAG eyes (33 myopia, 33 nonmyopia) and 66 normal eyes (33 myopia, 33 nonmyopia). Seven corneal biomechanical parameters were measured by ultra-high-speed Scheimpflug imaging, including corneal deformation amplitude (CDA), inward/outward corneal applanation length (ICA, OCA), inward/outward corneal velocity (ICV, OCV), radius, and peak distance (PD). Mean age (SD) of the 65 male (49%) and 67 female (51%) patients was 59 (9.82) years. Myopia was associated with significantly higher CDA (adjusted effect = 0.104, P = 0.001) and lower OCV (adjusted effect = -0.105, P < 0.001) in the POAG group. Within the nonglaucoma group, myopic eyes had a significantly lower OCV (adjusted effect = -0.086, P < 0.001) and higher CDA (adjusted effect = 0.079, P = 0.001). All parameters except PD suggested that glaucoma modified the effect of myopia on corneal biomechanics. Percentage differences in the adjusted myopic effect between POAG and nonglaucoma patients was 31.65, 27.27, 31.65, 50.00, 22.09, and 60.49 for CDA, ICA, OCA, ICV, OCV, and radius, respectively. Myopia had a significant impact on corneal biomechanical properties in the POAG and nonglaucoma groups. The differences in corneal biomechanical parameters suggest that myopia is correlated with significantly lower ocular rigidity. POAG may enhance the effects of myopia on most of these parameters.

INTERNATIONAL MYOPIA CONFERENCE PROCEEDINGS: CONFERENCE PAPER

PubMed Central

McFadden, Sally A.

2016-01-01

Tantalizing treatment options to limit further global increases in the prevalence of myopia are emerging. However, in order to design more effective interventions, we still need to learn more about the underlying causes of myopia and the associated biological changes. Based on the outcomes of the 2015 International Myopia Conference, this short article summarizes what more we still need to discover and suggests possible priorities for future research. PMID:27415440

Cataract in a patient with 47,XYY sex chromosome aneuploidy.

PubMed

Medina-Andrade, A; Villanueva-Mendoza, C; Arenas, S; Cortés-González, V

2018-06-01

The case concerns a 16 year-old boy with a history of high myopia and unilateral congenital cataract, tall stature for age, facial dysmorphism, hypermobile metacarpal-phalangeal joints, as well as behavioural problems. The mother had a history of recurrent pregnancy loss. Chromosomal analysis of the peripheral blood lymphocytes reported 47,XYY. Patients with sex chromosome aneuploidy 47,XYY have higher risk of congenital malformations, although ophthalmological anomalies are unusual. Evaluation of patients with tall stature and behavioural problems should include a chromosomal analysis in order to determine the aetiology. Copyright © 2017 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

Developing Agency through Peacebuilding in the Midst of Intractable Conflict: The Case of Israel and Palestine

ERIC Educational Resources Information Center

Plonski, Sharri

2005-01-01

This paper discusses the presence of "peacebuilding islands" within civil society as potential agents of transformation in the midst of intractable conflict. Focusing on the particular case of the Israeli-Palestinian conflict, the argument stems from a deconstruction of the legacy of national myopia perpetuated through social and…

Visually induced changes in components of the retinoic acid system in fundal layers of the chick.

PubMed

Bitzer, M; Feldkaemper, M; Schaeffel, F

2000-01-01

Eye growth is visually regulated via messengers that are released from the retina. The retina involves a yet unknown algorithm to analyse the projected image so that the appropriate growth rates for the back of the eye are ensured. One biochemical candidate that could act as a growth controller, is retinoic acid (RA). Previous work (Seko, Shimokawa and Tokoro, 1996; Mertz et al., 1999) has shown that retinal and choroidal RA levels are indeed predictably changed by visual conditions that cause myopia or hyperopia, respectively. We have studied in which fundal tissues aldehyde dehydrogenase-2 (AHD2) and retinaldehyde dehydrogenase-2 (RALDH2), enzymes involved in RA synthesis, are expressed and at which levels the effects of vision on RA levels may be controlled. Using Northern blot analysis, we have found that the retinal mRNA level of the AHD2 is up-regulated after 3 days of treatment with negative lenses (negative lenses place the image behind the retina). The abundance of the retinal mRNA of a RA receptor, RAR-beta, was up-regulated already after 6 hr of treatment with positive lenses (positive lenses place the image in front of the retina). The up-regulation persisted for at least 1 week. Finally, we have studied the effects of an inhibitor of RA synthesis, disulfiram, on the visual control of eye growth. We found inhibition of myopia as induced by frosted goggles ('deprivation myopia') but no significant inhibitory effects on refractive errors induced by +7D or -7D lenses. Our results are in line with the hypothesis that RA may play a role in the visual control of eye growth. The RA system differs from a number of other candidates (dopamine, cholinergic agents, opiates) in that it distinguishes between positive and negative defocus, similar to the immediate early gene ZENK (Stell et al., 1999). The exact time kinetics of the changes have still to be worked out since it is possible that the changes in RA relate to already occurring changes in growth rather than to initial steps of the signaling cascade. Copyright 2000 Academic Press.

The Effect of Age on Compensation for a Negative Lens and Recovery from Lens-induced Myopia in Tree Shrews (Tupaia glis belangeri)

PubMed Central

Norton, Thomas T.; Amedo, Angela O.; Siegwart, John T.

2010-01-01

We examined in tree shrews the effect of age on the development of, and recovery from, myopia induced with a negative lens. Starting at 11, 16, 24, 35 or 48 days after natural eye-opening (days of visual experience [VE]), juvenile tree shrews (n = 5 per group) wore a monocular −5 D lens for 11 days. A long-term lens-wear group (n=6) began treatment at 16 days of VE and wore the lens for 30 days. A young adult group (n = 5) began to wear a −5 D lens between 93 and 107 days of VE (mean ± SD, 100 ± 6 days of VE) and wore the lens for 29 to 54 days (mean ± SD, 41.8 ± 9.8 days). The recovery phase in all groups was started by discontinuing −5 D lens wear. Contralateral control eyes in the three youngest groups were compared with a group of age-matched normal eyes and showed a small (<1 D), transient myopic shift. The amount of myopia that developed during lens wear was measured as the difference between the treated and control eye refractions. After 11 days of lens wear, the induced myopia was similar for the four younger groups (near full compensation: 11 day, −5.1 ± 0.4 D; 16 day, −4.7 ± 0.3 D, 24 day, −4.9 ± 0.4 D; 35 day, −4.0 ± 0.02) and slightly less in the oldest juvenile group (48 day, −3.3 ± 0.5 D). The young adult animals developed −4.8 ± 0.3 D of myopia after a longer lens-wear period. The rate of compensation (D/day) was high in the 4 youngest groups and decreased in the 48-day and young adult groups. The refractions of the long-term lens-wear juvenile group remained stable after compensating for the −5 D lens. During recovery, all animals in the youngest group recovered fully (< 1 D residual myopia) within seven days. Examples of both rapid (< 10 days) and slow recovery (> 12 days) occurred in all age groups except the youngest. Every animal showed more rapid recovery (higher recovery slope) in the first 4 days than afterward. One animal showed extremely slow recovery. Based on the time-course of myopia development observed in the youngest age groups, the start of the susceptible period for negative lens wear is around 11 to 15 days after eye opening; the rate of compensation remains high until approximately 35 days of VE and then gradually declines. Compensation is stable with continued lens wear. The emmetropization mechanism, both for negative lens compensation and recovery, remains active into young adulthood. The time-course of recovery is more variable than that of compensation and seems to vary with age, with the amount of myopia (weakly) and with the individual animal. PMID:20045711

Exposure to Sunlight Reduces the Risk of Myopia in Rhesus Monkeys

PubMed Central

Wang, Yong; Ding, Hui; Stell, William K.; Liu, Liangping; Li, Saiqun; Liu, Hongshan; Zhong, Xingwu

2015-01-01

Exposure to sunlight has recently been postulated as responsible for the effect that more time spent outdoors protects children from myopia, while early life exposure to natural light was reported to be possibly related to onset of myopia during childhood. In this study, we had two aims: to determine whether increasing natural light exposure has a protective effect on hyperopic defocus-induced myopia, and to observe whether early postnatal exposure to natural light causes increased risk of refractive error in adolescence. Eight rhesus monkeys (aged 20-30 days) were treated monocularly with hyperopic-defocus (-3.0D lens) and divided randomly into two groups: AL group (n=4), reared under Artificial (indoor) Lighting (08:00-20:00); and NL group (n=4), exposed to Natural (outdoor) Light for 3 hours per day (11:00-14:00), and to indoor lighting for the rest of the light phase. After being reared with lenses for ca. 190 days, all monkeys were returned to unrestricted vision until the age of 3 years. Another eight age-matched monkeys, reared with unrestricted vision under artificial lighting since birth, were employed as controls. The ocular refraction, corneal curvature and axial dimensions were measured before lens-wearing (at 23±3 days of age), monthly during the light phase, and at the age of puberty (at 1185+3 days of age). During the lens-wearing treatment, infant monkeys in the NL group were more hyperopic than those in the AL group (F=5.726, P=0.032). Furthermore, the two eyes of most NL monkeys remained isometropic, whereas 3 of 4 AL monkeys developed myopic anisometropia more than -2.0D. At adolescence, eyes of AL monkeys showed significant myopic anisometropia compared with eyes of NL monkeys (AL vs NL: -1.66±0.87D vs -0.22±0.44D; P=0.002) and controls (AL vs Control: -1.66±0.87D vs -0.05±0.85D; P<0.0001). All differences in refraction were associated with parallel changes in axial dimensions. Our results suggest that exposure to natural outdoor light might have an effect to reduced hyperopic defocus-induced myopia. Also, the data imply that early life exposure to sunlight may help to maintain normal development of emmetropization later in life, and thus lower the risk of myopic anisometropia in adolescent monkey. PMID:26030845

Light Levels, Refractive Development, and Myopia – a Speculative Review

PubMed Central

Norton, Thomas T.; Siegwart, John T.

2013-01-01

Recent epidemiological evidence in children indicates that time spent outdoors is protective against myopia. Studies in animal models (chick, macaque, tree shrew) have found that light levels (similar to being in the shade outdoors) that are mildly elevated compared to indoor levels, slow form-deprivation myopia and (in chick and tree shrew) lens-induced myopia. Normal chicks raised in low light levels (50 lux) with a circadian light on/off cycle often develop spontaneous myopia. We propose a model in which the ambient illuminance levels produce a continuum of effects on normal refractive development and the response to myopiagenic stimuli such that low light levels favor myopia development and elevated levels are protective. Among possible mechanisms, elevation of retinal dopamine activity seems the most likely. Inputs from intrinsically-photosensitive retinal ganglion cells (ipRGCs) at elevated light levels may be involved, providing additional activation of retinal dopaminergic pathways. PMID:23680160

[Biological mechanisms of myopia].

PubMed

Schaeffel, F

2017-01-01

Recent studies have confirmed that the prevalence of myopia has increased in most countries, that the increase must be due to environmental factors and that myopia is closely linked to the level of education. Extensive close-up work with short viewing distances, little outdoor activity and continuous exposure to low illumination are currently considered the major factors. It remains unknown how close-up work can stimulate eye growth. Animal models provide the possibility to manipulate visual experiences and to observe subsequent changes in eye growth. They have uncovered a number of unexpected aspects which have led to studies in children. When applied in low doses atropine (0.01 %) is effective against progression of myopia and shows no rebound effect after termination of the treatment, in contrast to treatment with previously used higher doses. While education cannot be limited in our society, there are now an increasing number of options to slow myopia progression so that high myopia is less frequently reached.

[Comparative results evaluation of residual myopia and astigmatism correction after radial keratotomy by photorefraction keratectomy and laser specialized keratomileusis].

PubMed

Dias-Martines, T E; Sheludchenko, V M; Kurenkov, V V

1999-01-01

The results of correction of residual myopia by photorefraction keratectomy (PRK) (51 eyes) and laser specialized keratomileusis (LASIK) (36 eyes) after radial keratotomy (RK) are compared. The patients were observed for up to 12 months. After PRK, 7.3% patients developed late fleur of the cornea, evaluated by at least 2 points. The incidence of fleur directly depended on the value of residual myopia. After LASIK none of the patients developed such fleur. The best visual acuity (0.5 and higher without correction) was attained in 70.73% after PRK and RK, vs. 100% after LASIK. The results of photorefraction operations and severity of residual myopia after RK correlated. In residual myopia of up to -3 diopters the results of correction by PRK and LASIK were virtually the same. In residual myopia higher than -3 diopters, LASIK is preferable.

Retinitis pigmentosa inversa with unilateral high myopia with fellow eye optic disc pitting.

PubMed

Sheth, Saumil; Rush, Ryan; Narayanan, Raja

2011-01-01

To report a possible rare association of bilateral retinitis pigmentosa inversa (RPI) with unilateral high myopia with fellow eye optic disc pitting. A 55-year-old man with a history of reduced vision in the right eye since childhood presented with gradually decreasing vision in the left eye. On examination, a -23.00 diopter refractive error and diffuse chorioretinal atrophy consistent with pathologic myopia was found in the right eye. An optic disc pit with posterior pole pigmentary alterations thought to be consequent to a previous neurosensory detachment was found in the left eye. Though the retinal arteriolar attenuation seen in both eyes with an inconsistent history of night blindness since childhood pointed towards the possibility of a concurrently existing rod or rod-cone dystrophy, the posterior pole pigmentary alterations characteristic of RPI were clearly masked by the above pathologies. Optical coherence tomography demonstrated prominent foveal atrophy and an optic disc pit in the left eye. Electroretinography (ERG) demonstrated moderately attenuated amplitudes with prolonged implicit times of rod and cone responses bilaterally. The patient was diagnosed with bilateral RPI and anisometropic amblyopia in the right eye. This report documents a unique constellation of findings which include bilateral RPI and unilateral high myopia with an optic disc pit in the fellow eye. An ERG confirmation of a dystrophic etiology should be sought in suspicious cases, especially when findings are masked by the concurrent presence of other pathologies.

Identifying Children at Risk of High Myopia Using Population Centile Curves of Refraction.

PubMed

Chen, Yanxian; Zhang, Jian; Morgan, Ian G; He, Mingguang

2016-01-01

To construct reference centile curves of refraction based on population-based data as an age-specific severity scale to evaluate their efficacy as a tool for identifying children at risk of developing high myopia in a longitudinal study. Data of 4218 children aged 5-15 years from the Guangzhou Refractive Error Study in Children (RESC) study, and 354 first-born twins from the Guangzhou Twin Eye Study (GTES) with annual visit were included in the analysis. Reference centile curves for refraction were constructed using a quantile regression model based on the cycloplegic refraction data from the RESC. The risk of developing high myopia (spherical equivalent ≤ -6 diopters [D]) was evaluated as a diagnostic test using the twin follow-up data. The centile curves suggested that the 3rd, 5th, and 10th percentile decreased from -0.25 D, 0.00 D and 0.25 D in 5 year-olds to -6.00 D, -5.65D and -4.63 D in 15 year-olds in the population-based data from RESC. In the GTES cohort, the 5th centile showed the most effective diagnostic value with a sensitivity of 92.9%, a specificity of 97.9% and a positive predictive value (PPV) of 65.0% in predicting high myopia onset (≤-6.00D) before the age of 15 years. The PPV was highest (87.5%) in 3rd centile but with only 50.0% sensitivity. The Mathew's correlation coefficient of 5th centile in predicting myopia of -6.0D/-5.0D/-4.0D by age of 15 was 0.77/0.51/0.30 respectively. Reference centile curves provide an age-specific estimation on a severity scale of refractive error in school-aged children. Children located under lower percentiles at young age were more likely to have high myopia at 15 years or probably in adulthood.

Comparison of visual acuity of the patients on the first day after sub-Bowman keratomileusis or laser in situ keratomileusis

PubMed Central

Zhao, Wei; Wu, Ting; Dong, Ze-Hong; Feng, Jie; Ren, Yu-Feng; Wang, Yu-Sheng

2016-01-01

AIM To compare recovery of the visual acuity in patients one day after sub-Bowman keratomileusis (SBK) or laser in situ keratomileusis (LASIK). METHODS Data from 5923 eyes in 2968 patients that received LASIK (2755 eyes) or SBK (3168 eyes) were retrospectively analyzed. The eyes were divided into 4 groups according to preoperative spherical equivalent: between -12.00 to -9.00 D, extremely high myopia (n=396, including 192 and 204 in SBK and LASIK groups, respectively); -9.00 to -6.00 D, high myopia (n=1822, including 991 and 831 in SBK and LASIK groups, respectively), -6.00 to -3.00 D, moderate myopia (n=3071, including 1658 and 1413 in SBK and LASIK groups, respectively), and -3.00 to 0.00 D, low myopia (n=634, including 327 and 307 in SBK and LASIK groups, respectively). Uncorrected logMAR visual acuity values of patients were assessed under standard natural light. Analysis of variance was used for comparisons among different groups. RESULTS Uncorrected visual acuity values were 0.0115±0.1051 and 0.0466±0.1477 at day 1 after operation for patients receiving SBK and LASIK, respectively (P<0.01); visual acuity values of 0.1854±0.1842, 0.0615±0.1326, -0.0033±0.0978, and -0.0164±0.0972 were obtained for patients in the extremely high, high, moderate, and low myopia groups, respectively (P<0.01). In addition, significant differences in visual acuity at day 1 after operation were found between patients receiving SBK and LASIK in each myopia subgroup. CONCLUSION Compared with LASIK, SBK is safer and more effective, with faster recovery. Therefore, SBK is more likely to be accepted by patients than LASIK for better uncorrected visual acuity the day following operation. PMID:27158619

Association Between Myopia, Ultraviolet B Radiation Exposure, Serum Vitamin D Concentrations, and Genetic Polymorphisms in Vitamin D Metabolic Pathways in a Multicountry European Study.

PubMed

Williams, Katie M; Bentham, Graham C G; Young, Ian S; McGinty, Ann; McKay, Gareth J; Hogg, Ruth; Hammond, Christopher J; Chakravarthy, Usha; Rahu, Mati; Seland, Johan; Soubrane, Gisele; Tomazzoli, Laura; Topouzis, Fotis; Fletcher, Astrid E

2017-01-01

Myopia is becoming increasingly common globally and is associated with potentially sight-threatening complications. Spending time outdoors is protective, but the mechanism underlying this association is poorly understood. To examine the association of myopia with ultraviolet B radiation (UVB; directly associated with time outdoors and sunlight exposure), serum vitamin D concentrations, and vitamin D pathway genetic variants, adjusting for years in education. A cross-sectional, population-based random sample of participants 65 years and older was chosen from 6 study centers from the European Eye Study between November 6, 2000, to November 15, 2002. Of 4187 participants, 4166 attended an eye examination including refraction, gave a blood sample, and were interviewed by trained fieldworkers using a structured questionnaire. Myopia was defined as a mean spherical equivalent of -0.75 diopters or less. Exclusion criteria included aphakia, pseudophakia, late age-related macular degeneration, and vision impairment due to cataract, resulting in 371 participants with myopia and 2797 without. Exposure to UVB estimated by combining meteorological and questionnaire data at different ages, single-nucleotide polymorphisms in vitamin D metabolic pathway genes, serum vitamin D3 concentrations, and years of education. Odds ratios (ORs) of UVB, serum vitamin D3 concentrations, vitamin D single-nucleotide polymorphisms, and myopia estimated from logistic regression. Of the included 3168 participants, the mean (SD) age was 72.4 (5) years, and 1456 (46.0%) were male. An SD increase in UVB exposure at age 14 to 19 years (OR, 0.81; 95% CI, 0.71-0.92) and 20 to 39 years (OR, 0.7; 95% CI, 0.62-0.93) was associated with a reduced adjusted OR of myopia; those in the highest tertile of years of education had twice the OR of myopia (OR, 2.08; 95% CI, 1.41-3.06). No independent associations between myopia and serum vitamin D3 concentrations nor variants in genes associated with vitamin D metabolism were found. An unexpected finding was that the highest quintile of plasma lutein concentrations was associated with a reduced OR of myopia (OR, 0.57; 95% CI, 0.46-0.72). Increased UVB exposure was associated with reduced myopia, particularly in adolescence and young adulthood. The association was not altered by adjusting for education. We found no convincing evidence for a direct role of vitamin D in myopia risk. The relationship between high plasma lutein concentrations and a lower risk of myopia requires replication.

Influence of indoor and outdoor activities on progression of myopia during puberty.

PubMed

Öner, Veysi; Bulut, Asker; Oruç, Yavuz; Özgür, Gökhan

2016-02-01

The purpose of this study was to investigate whether time spent on indoor and outdoor activities or the other possible risk factors including age, gender, parental history, and initial refraction was associated with progression of myopia, during puberty. Fifty eyes of 50 myopic children aged 9-14 years were enrolled in the study. The parents were interviewed to determine the amounts of time in hours per day spent on reading and writing, using computer, watching TV, and outdoor activities (i.e., sports, games, or being outdoor with no activities) on an average day. The annual myopia progression rate (diopters per year) was calculated for each subject and was used in the statistical analyses. The mean initial age of the subjects was 10.9 ± 1.5 (ranging from 9 to 14) years. The mean follow-up period was 33.3 ± 10.3 (ranging from 17 to 55) months. There was a significant increase in the mean myopia value of the subjects after follow-up period (p < 0.001). The mean daily time spent on reading and writing and initial refraction value were independently associated with annual myopic progression rate. On the other hand, age, gender, parental myopia, and the mean daily times spent on computer use, watching TV, and outdoor activities had no correlations with annual myopia progression rate. The present study showed that myopia progression was associated with time spent on reading and writing and initial refraction value, during puberty. However, myopia progression was not associated with parental myopia, age, gender, and daily times spent on using computer, watching TV, and outdoor activities.

Inverse relationship between sleep duration and myopia.

PubMed

Jee, Donghyun; Morgan, Ian G; Kim, Eun Chul

2016-05-01

To investigate the association between sleep duration and myopia. This population-based, cross-sectional study using a nationwide, systemic, stratified, multistage, clustered sampling method included a total of 3625 subjects aged 12-19 years who participated in the Korean National Health and Nutrition Examination Survey 2008-2012. All participants underwent ophthalmic examination and a standardized interview including average sleep duration (hr/day), education, physical activity and economic status (annual household income). Refractive error was measured by autorefraction without cycloplegia. Myopia and high myopia were defined as ≤-0.50 dioptres (D) and ≤-6.0 D, respectively. Sleep durations were classified into 5 categories: <5, 6, 7, 8 and >9 hr. The overall prevalence of myopia and high myopia were 77.8% and 9.4%, respectively, and the overall sleep duration was 7.1 hr/day. The refractive error increased by 0.10 D per 1 hr increase in sleep after adjusting for potential confounders including sex, age, height, education level, economic status and physical activity. The adjusted odds ratio (OR) for refractive error was 0.90 (95% confidence interval [CI], 0.83-0.97) per 1 hr increase in sleep. The adjusted OR for myopia was decreased in those with >9 hr of sleep (OR, 0.59; 95% CI, 0.38-0.93; p for trend = 0.006) than in those with <5 hr of sleep. However, high myopia was not associated with sleep duration. This study provides the population-based, epidemiologic evidence for an inverse relationship between sleep duration and myopia in a representative population of Korean adolescents. © 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Time Outdoors at Specific Ages During Early Childhood and the Risk of Incident Myopia.

PubMed

Shah, Rupal L; Huang, Yu; Guggenheim, Jeremy A; Williams, Cathy

2017-02-01

Time outdoors during childhood is negatively associated with incident myopia. Consequently, additional time outdoors has been suggested as a public health intervention to reduce the prevalence of myopia. We investigated whether there were specific ages during early childhood when the time outdoors versus incident myopia association was strongest. Children participating in the Avon Longitudinal Study of Parents and Children (ALSPAC) were studied from age 2 to 15 years. Parentally reported time outdoors and time spent reading were assessed longitudinally in early childhood (ages 2, 3, 4, 5, 7, and 9 years). Noncycloplegic autorefraction was carried out longitudinally in later childhood (ages 10, 11, 12, and 15 years). Information was available for 2833 participants. Cox proportional hazards regression was used to test for association between time outdoors and incident myopia. From 3 years of age onward, greater time outdoors was associated with a reduced risk of incident myopia. The hazard ratio for myopia changed progressively from 0.90 (95% CI 0.83-0.98, P = 0.012) at age 3 years, to 0.86 (95% CI 0.78-0.93, P = 0.001) at age 9 years, for each additional SD of time spent outdoors per day. These associations were independent of two major risk factors for myopia: time reading and number of myopic parents. Additional time spent outdoors across the 3 to 9 years age range was associated with a reduced incidence of myopia between ages 10 and 15 years. There was a trend for the association to increase toward the older end of the 3 to 9 years range.

Progressive myopia or hyperopia can be induced in chicks and reversed by manipulation of the chromaticity of ambient light.

PubMed

Foulds, Wallace S; Barathi, Veluchamy A; Luu, Chi D

2013-12-09

To determine whether progressive ametropia can be induced in chicks and reversed by manipulation of the chromaticity of ambient light. One-day-old chicks were raised in red light (90% red, 10% yellow-green) or in blue light (85% blue, 15% green) with a 12 hour on/off cycle for 14 to 42 days. Refraction was determined by streak retinoscopy, and by automated infrared photoretinoscopy and ocular biometry by A-scan ultrasonography. Red light induced progressive myopia (mean refraction ± SD at 28 days, -2.83 ± 0.25 diopters [D]). Progressive hyperopia was induced by blue light (mean refraction at 28 days, +4.55 ± 0.21 D). The difference in refraction between the groups was highly significant at P < 0.001. Induced myopia or hyperopia was axial as confirmed by ultrasound biometry. Myopia induced by 21 days of red light (-2.21 ± 0.21 D) was reversed to hyperopia (+2.50 ± 0.29 D) by subsequent 21 days of blue light. Hyperopia induced by 21 days of blue light (+4.21 ± 0.19 D) was reversed to myopia (-1.23 ± 0.12 D) by 21 days of red light. Rearing chicks in red light caused progressive myopia, while rearing in blue light caused progressive hyperopia. Light-induced myopia or hyperopia in chicks can be reversed to hyperopia or myopia, respectively, by an alteration in the chromaticity of ambient light. Manipulation of chromaticity may be applicable to the management of human childhood myopia.

Impact of Myopia on Corneal Biomechanics in Glaucoma and Nonglaucoma Patients

PubMed Central

Panpruk, Rawiphan; Manassakorn, Anita; Tantisevi, Visanee; Rojanapongpun, Prin; Hurst, Cameron P.; Lin, Shan C.

2017-01-01

Purpose We evaluated the impact of myopia on corneal biomechanical properties in primary open-angle glaucoma (POAG) and nonglaucoma patients, and the effect of modification of glaucoma on myopic eyes. Methods This cross-sectional study included 66 POAG eyes (33 myopia, 33 nonmyopia) and 66 normal eyes (33 myopia, 33 nonmyopia). Seven corneal biomechanical parameters were measured by ultra-high-speed Scheimpflug imaging, including corneal deformation amplitude (CDA), inward/outward corneal applanation length (ICA, OCA), inward/outward corneal velocity (ICV, OCV), radius, and peak distance (PD). Results Mean age (SD) of the 65 male (49%) and 67 female (51%) patients was 59 (9.82) years. Myopia was associated with significantly higher CDA (adjusted effect = 0.104, P = 0.001) and lower OCV (adjusted effect = −0.105, P < 0.001) in the POAG group. Within the nonglaucoma group, myopic eyes had a significantly lower OCV (adjusted effect = −0.086, P < 0.001) and higher CDA (adjusted effect = 0.079, P = 0.001). All parameters except PD suggested that glaucoma modified the effect of myopia on corneal biomechanics. Percentage differences in the adjusted myopic effect between POAG and nonglaucoma patients was 31.65, 27.27, 31.65, 50.00, 22.09, and 60.49 for CDA, ICA, OCA, ICV, OCV, and radius, respectively. Conclusions Myopia had a significant impact on corneal biomechanical properties in the POAG and nonglaucoma groups. The differences in corneal biomechanical parameters suggest that myopia is correlated with significantly lower ocular rigidity. POAG may enhance the effects of myopia on most of these parameters. PMID:28979996

Disordered sleep and myopia risk among Chinese children.

PubMed

Zhou, Zhongqiang; Morgan, Ian G; Chen, Qianyun; Jin, Ling; He, Mingguang; Congdon, Nathan

2015-01-01

Disordered sleep and myopia are increasingly prevalent among Chinese children. Similar pathways may be involved in regulation of both sleep cycles and eye growth. We therefore sought to examine the association between disordered sleep and myopia in this group. Urban primary school children participating in a clinical trial on myopia and outdoor activity underwent automated cycloplegic refraction with subjective refinement. Parents answered questions about children's sleep duration, sleep disorders (Children's Sleep Habits Questionnaire [CSHQ]), near work and time spent outdoors. Among 1970 children, 1902 (96.5%, mean [standard deviation SD] age 9.80 [0.44] years, 53.1% boys) completed refraction and questionnaires. Myopia < = -0.50 Diopters was present in both eyes of 588 (30.9%) children (1329/3804 = 34.9% of eyes) and 1129 children (59.4%) had abnormal CSHQ scores (> 41). In logistic regression models by eye, odds of myopia < = -0.50D increased with worse CSHQ score (Odds Ratio [OR] 1.01 per point, 95% Confidence Interval [CI] [1.001, 1.02], P = 0.014) and more night-time sleep (OR 1.02, 95% CI [1.01, 1.04, P = 0.002], while male sex (OR 0.82, 95% CI [0.70, 0.95], P = 0.008) and time outdoors (OR = 0.97, 95% CI [0.95, 0.99], P = 0.011) were associated with less myopia. The association between sleep duration and myopia was not significant (p = 0.199) for total (night + midday) sleep. Myopia and disordered sleep were both common in this cohort, but we did not find consistent evidence for an association between the two. clinicaltrials.gov NCT00848900.

Progression of myopia and high myopia in the Early Treatment for Retinopathy of Prematurity study: findings at 4 to 6 years of age.

PubMed

Quinn, Graham E; Dobson, Velma; Davitt, Bradley V; Wallace, David K; Hardy, Robert J; Tung, Betty; Lai, Dejian; Good, William V

2013-04-01

To report the prevalence of myopia and high myopia in children <6 years of age born preterm with birth weights <1251 g who developed high-risk prethreshold retinopathy of prematurity and who participated in the Early Treatment for Retinopathy of Prematurity trial. Surviving children from the cohort of 401 participants who had developed high-risk prethreshold ROP in one or both eyes underwent cycloplegic retinoscopy at 6 and 9 months corrected age and yearly between 2 and 6 years postnatal age. Eyes were randomized to receive treatment at high-risk prethreshold ROP or conventional management with treatment only if threshold ROP developed. Myopia (spherical equivalent ≥0.25 D) or high myopia (≥5.00 D) in eyes at 4-, 5-, and 6-year examinations was reported. At ages 4, 5, and 6 years, there was no difference in the percentage of eyes with myopia (range, 64.8%-69.9%) and eyes with high myopia (range, 35.3%-39.4%) between earlier treated and conventionally managed eyes. Approximately two-thirds of eyes with high-risk prethreshold ROP during the neonatal period are likely to be myopic into the preschool and early school years. In addition, the increase in the proportion of eyes with high myopia that had been observed in both earlier-treated and conventionally managed eyes between ages 6 months and 3 years does not continue between ages 3 and 6 years. Copyright © 2013 American Association for Pediatric Ophthalmology and Strabismus. Published by Mosby, Inc. All rights reserved.

A microarray analysis of retinal transcripts that are controlled by image contrast in mice

PubMed Central

Brand, Christine; Schaeffel, Frank

2007-01-01

Purpose The development of myopia is controlled by still largely unknown retinal signals. The aim of this study was to investigate the changes in retinal mRNA expression after different periods of visual deprivation in mice, while controlling for retinal illuminance. Methods Each group consisted of three male C57BL/6 mice. Treatment periods were 30 min, 4 h, and 6+6 h. High spatial frequencies were filtered from the retinal image by frosted diffusers over one eye while the fellow eyes were covered by clear neutral density (ND) filters that exhibited similar light attenuating properties (0.1 log units) as the diffusers. For the final 30 min of the respective treatment period mice were individually placed in a clear Perspex cylinder that was positioned in the center of a rotating (60 degrees) large drum. The inside of the drum was covered with a 0.1 cyc/degree vertical square wave grating. This visual environment was chosen to standardize illuminances and contrasts seen by the mice. Labeled cRNA was prepared and hybridized to Affymetrix GeneChip® Mouse Genome 430 2.0 arrays. Alterations in mRNA expression levels of candidate genes with potential biological relevance were confirmed by semi-quantitative real-time reverse transcription polymerase chain reaction (RT-PCR). Results In all groups, Egr-1 mRNA expression was reduced in diffuser-treated eyes. Furthermore, the degradation of the spatial frequency spectrum also changed the cFos mRNA level, with reduced expression after 4 h of diffuser treatment. Other interesting candidates were Akt2, which was up-regulated after 30 min of deprivation and Mapk8ip3, a neuron specific JNK binding and scaffolding protein that was temporally regulated in the diffuser-treated eyes only. Conclusions The microarray analysis demonstrated a pattern of differential transcriptional changes, even though differences in the retinal images were restricted to spatial features. The candidate genes may provide further insight into the biochemical short-term changes following retinal image degradation in mice. Because deprivation of spatial vision leads to increased eye growth and myopia in both animals and humans, it is believed some of the identified genes play a role in myopia development. PMID:17653032

Role of Chronic Inflammation in Myopia Progression: Clinical Evidence and Experimental Validation.

PubMed

Lin, Hui-Ju; Wei, Chang-Ching; Chang, Ching-Yao; Chen, Ter-Hsin; Hsu, Yu-An; Hsieh, Yi-Ching; Chen, Hsuan-Ju; Wan, Lei

2016-08-01

Prevention and treatment of myopia is an important public problem worldwide. We found a higher incidence of myopia among patients with inflammatory diseases such as type 1 diabetes mellitus (7.9%), uveitis (3.7%), or systemic lupus erythematosus (3.5%) compared to those without inflammatory diseases (p<0.001) using data from children (<18years old) in the National Health Insurance Research database. We then examined the inhibition of myopia by atropine in Syrian hamsters with monocular form deprivation (MFD), an experimental myopia model. We found atropine downregulated inflammation in MFD eyes. The expression levels of c-Fos, nuclear factor κB (NFκB), interleukin (IL)-6, and tumor necrosis factor (TNF)-α were upregulated in myopic eyes and downregulated upon treatment with atropine. The relationship between the inflammatory response and myopia was investigated by treating MFD hamsters with the immunosuppressive agent cyclosporine A (CSA) or the inflammatory stimulators lipopolysaccharide (LPS) or peptidoglycan (PGN). Myopia progression was slowed by CSA application but was enhanced by LPS and PGN administration. The levels of c-Fos, NF-κB, IL-6, and TNF-α were upregulated in LPS- and PGN-treated eyes and downregulated by CSA treatment. These findings provide clinical and experimental evidence that inflammation plays a crucial role in the development of myopia. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Myopia and educational attainment in 421,116 young Singaporean males.

PubMed

Tay, M T; Au Eong, K G; Ng, C Y; Lim, M K

1992-11-01

Data of 421,116 Singaporean males aged 15 to 25 (mean 17.75) years who underwent compulsory medical examination in 1974-84 and 1987-91 were used to estimate the prevalence of myopia and to study the correlation between the prevalence and severity of myopia and educational attainment. The estimated myopia prevalence rate was 26.3% in 1974-84 and 43.3% in 1987-91. This rise in the rate was accompanied by an increase in the proportion of males who achieved higher levels of education over the same period. The overall myopia prevalence rate was 30.4%. Both the prevalence and severity of myopia were higher as the level of education attained increased. The myopia prevalence rate was 15.4% in males with no formal education and increased steadily through groups with intermediate education to 65.2% among those with GCE 'A' level education, 57.5% among diploma holders and 65.1% among university graduates in 1987-91. Seventy out of 173 (40%) myopes with no formal education compared to 1035 out of 1612 (64%) myopes with university degrees had unaided visual acuity worse than 6/60 in 1987-91. Our findings confirm indications from other sources that the association between the prevalence and severity of myopia and education attainment is real. A combination of genetic and environmental factors may be the cause of this association.

Myopia prevalence in Chinese-Canadian children in an optometric practice.

PubMed

Cheng, Desmond; Schmid, Katrina L; Woo, George C

2007-01-01

The high prevalence of myopia in Chinese children living in urban East Asian countries such as Hong Kong, Taiwan, and China has been well documented. However, it is not clear whether the prevalence of myopia would be similarly high for this group of children if they were living in a Western country. This study aims to determine the prevalence and progression of myopia in ethnic Chinese children living in Canada. Right eye refraction data of Chinese-Canadian children aged 6 to 12 years were collated from the 2003 clinical records of an optometric practice in Mississauga, Ontario, Canada. Myopia was defined as a spherical equivalent refraction (SER) equal or less than -0.50 D. The prevalence of myopia and refractive error distribution in children of different ages and the magnitude of refractive error shifts over the preceding 8 years were determined. Data were adjusted for potential biases in the clinic sample. A questionnaire was administered to 300 Chinese and 300 Caucasian children randomly selected from the clinic records to study lifestyle issues that may impact on myopia development. Optometric records of 1468 children were analyzed (729 boys and 739 girls). The clinic bias adjusted prevalence of myopia increased from 22.4% at age 6 to 64.1% at age 12 and concurrently the portion of the children that were emmetropic (refraction between -0.25 and +0.75 D) decreased (68.6% at 6 years to 27.2% at 12 years). The highest incidence of myopia for both girls ( approximately 35%) and boys ( approximately 25%) occurred at 9 and 10 years of age. The average annual refractive shift for all children was -0.52+/-0.42 D and -0.90+/-0.40 D for just myopic children. The questionnaire revealed that these Chinese-Canadian children spent a greater amount of time performing near work and less time outdoors than did Caucasian-Canadian children. Ethnic Chinese children living in Canada develop myopia comparable in prevalence and magnitude to those living in urban East Asian countries. Recent migration of the children and their families to Canada does not appear to lower their myopia risk.

Effectiveness study of atropine for progressive myopia in Europeans

PubMed Central

Polling, J R; Kok, R G W; Tideman, J W L; Meskat, B; Klaver, C C W

2016-01-01

Purpose Randomized controlled trials have shown the efficacy of atropine for progressive myopia, and this treatment has become the preferred pattern for this condition in Taiwan. This study explores the effectiveness of atropine 0.5% treatment for progressive high myopia and adherence to therapy in a non-Asian country. Methods An effectiveness study was performed in Rotterdam, the Netherlands. Overall 77 children (mean age 10.3 years±2.3), of European (n=53), Asian (n=18), and African (n=6) descent with progressive myopia were prescribed atropine 0.5% eye drops daily. Both parents and children filled in a questionnaire regarding adverse events and adherence to therapy. A standardized eye examination including cycloplegic refraction and axial length was performed at baseline and 1, 4, and 12 months after initiation of therapy. Results Mean spherical equivalent at baseline was −6.6D (±3.3). The majority (60/77, 78%) of children adhered to atropine treatment for 12 months; 11 of the 17 children who discontinued therapy did so within 1 month after the start of therapy. The most prominent reported adverse events were photophobia (72%), followed by reading problems (38%), and headaches (22%). The progression rate of spherical equivalent before treatment (−1.0D/year±0.7) diminished substantially during treatment (−0.1D/year±0.7) compared to those who ceased therapy (−0.5D/year±0.6; P=0.03). Conclusions Despite the relatively high occurrence of adverse events, our study shows that atropine can be an effective and sustainable treatment for progressive high myopia in Europeans. PMID:27101751

The prevalence rates of refractive errors among children, adolescents, and adults in Germany.

PubMed

Jobke, Sandra; Kasten, Erich; Vorwerk, Christian

2008-09-01

The prevalence rates of myopia vary between 5% in Australian Aborigines to 84% in Hong Kong and Taiwan, 30% in Norwegian adults, and 49.5% in Swedish schoolchildren. The aim of this study was to determine the prevalence of refractive errors in German children, adolescents, and adults. The parents (aged 24-65 years) and their children (516 subjects aged 2-35 years) were asked to fill out a questionnaire about their refractive error and spectacle use. Emmetropia was defined as refractive status between +0.25D and -0.25D. Myopia was characterized as /=+0.5D. All information concerning refractive error were controlled by asking their opticians. The prevalence rates of myopia differed significantly between all investigated age groups: it was 0% in children aged 2-6 years, 5.5% in children aged 7-11 years, 21.0% in adolescents (aged 12-17 years) and 41.3% in adults aged 18-35 years (Pearson's Chi-square, p = 0.000). Furthermore, 9.8% of children aged 2-6 years were hyperopic, 6.4% of children aged 7-11 years, 3.7% of adolescents, and 2.9% of adults (p = 0.380). The prevalence of myopia in females (23.6%) was significantly higher than in males (14.6%, p = 0.018). The difference between the self-reported and the refractive error reported by their opticians was very small and was not significant (p = 0.850). In Germany, the prevalence of myopia seems to be somewhat lower than in Asia and Europe. There are few comparable studies concerning the prevalence rates of hyperopia.

A sample predictive model for intraocular pressure following laser in situ keratomileusis for myopia and an "intraocular pressure constant".

PubMed

Bahadir Kilavuzoglu, Ayse Ebru; Bozkurt, Tahir Kansu; Cosar, Cemile Banu; Sener, Asım Bozkurt

2017-06-24

To describe a sample predictive model for intraocular pressure (IOP) following laser in situ keratomileusis (LASIK) for myopia and an IOP constant. The records of patients that underwent LASIK for myopia and myopic astigmatism via WaveLight Allegretto Wave Eye-Q 400 Hz excimer laser and Hansatome XP microkeratome were retrospectively reviewed. Patients with no systemic or ocular disease other than myopia or myopic astigmatism were included in the study. Preoperative and postoperative month 1 data and intraoperative data were used to build the predictive model for IOP after LASIK. The IOP constant was calculated by subtracting the predicted IOP from preoperative IOP. The paired samples t test, Pearson's correlation analysis, curve estimation analysis, and linear regression analysis were used to evaluate the study data. The study included 425 eyes in 214 patients with a mean age of 32 ± 7.8 years. Mean spherical equivalent of the attempted correction (SE-ac) was -3.7 ± 1.7 diopters. Mean post-LASIK decrease in IOP was 4.6 ± 2.3 mmHg. The difference between preoperative and postoperative IOP was statistically significant (P < 0.001). SE-ac, preoperative IOP, and central corneal thickness had highly significant effects on postoperative IOP, based on linear regression analysis (P < 0.001 and R 2  = 0.043, P < 0.001 and R 2  = 0.370, and P < 0.001 and R 2  = 0.132, respectively). Regression model was created (F = 127.733, P < 0.001), and the adjusted R 2 value was 0.548. Evaluation of IOP after LASIK is important in myopic patients. The present study described a practical formula for predicting the true IOP with the aid of an IOP constant value in myopic eyes following LASIK.

Refractive Outcomes of Three-Port Lens-Sparing Vitrectomy for Retinopathy of Prematurity (An AOS Thesis)

PubMed Central

Holz, Eric R.

2009-01-01

Purpose: To study the refractive outcomes of 3-port lens-sparing vitrectomy (LSV) for subtotal retinal detachments due to retinopathy of prematurity (ROP). Lens-sparing vitrectomy may provide superior refractive outcomes by limiting induced myopia of prematurity. Methods: This is a retrospective, consecutive, nonrandomized, comparative (paired eye) study. Entrance criteria were previous complete ablative laser for threshold ROP in both eyes, followed by LSV in one eye for stage 4A traction retinal detachment. Both eyes then maintained complete retinal attachment. Main outcome variables were cycloplegic refraction, keratometry, and biometric values for axial length, lens thickness, and anterior chamber depth. Results: Nine patients met inclusion criteria. Lens-sparing vitrectomy eyes were significantly less myopic than control eyes (−6.78 D vs −10.33 D, P < .005). The reduction in myopia in LSV eyes was predominantly due to increased anterior chamber depth (3.81 mm ± 0.217 vs 2.96 mm ± 0.232, P < .005). There was a minor contribution from reduced corneal power in LSV eyes (43.89 D ± 0.253 vs 44.20 D ± 0.265, P < .005). There was a minor negative impact from increased lens thickness in LSV eyes (3.85 ± 0.32 mm vs 3.74 ± 0.31, P < .005). There was no significant difference in axial length or lens power between the LSV and control groups. Conclusions: The data demonstrate that infant eyes undergoing 3-port LSV for stage 4A ROP develop less myopia than fellow eyes treated with laser alone. The difference is due to posterior displacement of the lens-iris diaphragm with a smaller contribution from reduced corneal power. The reduction in myopia may improve functional outcomes following 3-port LSV for stage 4A ROP. PMID:20126504

Prevalence of refractive errors in the European adult population: the Gutenberg Health Study (GHS).

PubMed

Wolfram, Christian; Höhn, René; Kottler, Ulrike; Wild, Philipp; Blettner, Maria; Bühren, Jens; Pfeiffer, Norbert; Mirshahi, Alireza

2014-07-01

To study the distribution of refractive errors among adults of European descent. Population-based eye study in Germany with 15010 participants aged 35-74 years. The study participants underwent a detailed ophthalmic examination according to a standardised protocol. Refractive error was determined by an automatic refraction device (Humphrey HARK 599) without cycloplegia. Definitions for the analysis were myopia <-0.5 dioptres (D), hyperopia >+0.5 D, astigmatism >0.5 cylinder D and anisometropia >1.0 D difference in the spherical equivalent between the eyes. Exclusion criterion was previous cataract or refractive surgery. 13959 subjects were eligible. Refractive errors ranged from -21.5 to +13.88 D. Myopia was present in 35.1% of this study sample, hyperopia in 31.8%, astigmatism in 32.3% and anisometropia in 13.5%. The prevalence of myopia decreased, while the prevalence of hyperopia, astigmatism and anisometropia increased with age. 3.5% of the study sample had no refractive correction for their ametropia. Refractive errors affect the majority of the population. The Gutenberg Health Study sample contains more myopes than other study cohorts in adult populations. Our findings do not support the hypothesis of a generally lower prevalence of myopia among adults in Europe as compared with East Asia.

[A clinical study and analysis of congenital lenticular dislocation (35 cases)].

PubMed

Guo, X; Mao, W; Chen, Y; Ma, Q; Zeng, L; Luo, T

1991-12-01

Thirty-five cases of congenital lenticular dislocation seen in our Center since 1985 have been studied and analyzed clinically. By the survey of pedigrees and examination of these patients, including ocular, systemic, skeletal X-ray, psychocardiogram, and urinary sodium-nitroprusside test, 21 cases were diagnosed as Marfan's syndrome, 6 cases as simple ectopia lentis, 3 cases as Weill-Marchesani's syndrome, 4 cases as aniridia and 1 case as homecys tinuria. We found that the most significant ocular manifestation of congenital lenticular dislocation was reduction in visual acuity. The severity of visual disturbance varied with the types of dislocation and the visual deficiency was closely related to the intermediate-grade (II) dislocation of the lens. Examination of ERG showed normal function in most of the patients. From this, we believe that the major cause of visual reduction in congenital lenticular dislocation is lenticular myopia and astigmatism. There fore, early diagnosis and effective correction of vision should be emphasized to prevent the occurrence of amblyopia.

The role of microRNAs in myopia.

PubMed

Jiang, Bo; Huo, Yanan; Gu, Yangshun; Wang, Jianyong

2017-01-01

In recent years, research on microRNAs (miRNAs) has become popular because of the critical role these macromolecules play in post-transcriptional gene regulation. Recent efforts have been made to identify miRNAs and their possible roles in myopia. The aim of this review was to summarize the expression and function of miRNAs during the development of myopia. In this article, we reviewed the current research on the mechanisms that regulate miRNA expression, the potential for miRNAs as a diagnostic biomarker for myopia, and the mechanisms by which miRNAs promote the development of myopia. We also discussed the miRNA expression profiles in human fetal sclera. We summarized the miRNA expression profiles in myopia, including miR-328, miR-184, miR-29a, and miR-let-7i, and also the miRNA expression profiles in fetal sclera, including miR-214, miR-let-7, miR-103, miR-107, miR-29b, miR-328, and miR-98. Such knowledge could lead to more precise diagnosis, prognosis, and response predictions for future treatments for myopia, and the pace of discovery is expected to accelerate dramatically in the near future.

Kawasaki Disease Increases the Incidence of Myopia.

PubMed

Kung, Yung-Jen; Wei, Chang-Ching; Chen, Liuh An; Chen, Jiin Yi; Chang, Ching-Yao; Lin, Chao-Jen; Lim, Yun-Ping; Tien, Peng-Tai; Chen, Hsuan-Ju; Huang, Yong-San; Lin, Hui-Ju; Wan, Lei

2017-01-01

The prevalence of myopia has rapidly increased in recent decades and has led to a considerable global public health concern. In this study, we elucidate the relationship between Kawasaki disease (KD) and the incidence of myopia. We used Taiwan's National Health Insurance Research Database to conduct a population-based cohort study. We identified patients diagnosed with KD and individuals without KD who were selected by frequency matched based on sex, age, and the index year. The Cox proportional hazards regression model was used to estimate the hazard ratio and 95% confidence intervals for the comparison of the 2 cohorts. The log-rank test was used to test the incidence of myopia in the 2 cohorts. A total of 532 patients were included in the KD cohort and 2128 in the non-KD cohort. The risk of myopia (hazard ratio, 1.31; 95% confidence interval, 1.08-1.58; P < 0.01) was higher among patients with KD than among those in the non-KD cohort. The Cox proportional hazards regression model showed that irrespective of age, gender, and urbanization, Kawasaki disease was an independent risk factor for myopia. Patients with Kawasaki disease exhibited a substantially higher risk for developing myopia.

Epidemiology of myopia

PubMed Central

Foster, P J; Jiang, Y

2014-01-01

Myopia is one of the most prevalent disorders of the eye. Higher myopia is associated with comorbidities that increase risks of severe and irreversible loss of vision, such as retinal detachment, subretinal neovascularization, dense cataract, and glaucoma. In recent years, reports from population-based prevalence studies carried out in various geographical areas now give a clear picture of the current distribution of refractive error. The scarcity of data from well-designed longitudinal cohort studies is still yet to be addressed. These studies have confirmed the previous data indicating that prevalence of refractive error varies according to ethnicity and geographic regions, and also point to an increase in myopia prevalence over the past half-century. The problem is particularly pronounced in affluent, industrialised areas of East Asia. Environmental risk factors for myopia related to socioeconomic status and lifestyle have been identified. The past decade has seen a greater understanding of the molecular biological mechanisms that determine refractive error, giving further support to the belief that myopia is the result of a complex interaction between genetic predisposition and environmental exposures. This review summarizes data on the prevalence, incidence, progression, associations, risk factors, and impact from recent epidemiological studies on myopia. PMID:24406412

Evaluation of high myopia complications prevention program in university freshmen

PubMed Central

Tseng, Gow-Lieng; Chen, Cheng-Yu

2016-01-01

Abstract High myopia is a global eye health problem because of its high incidence of sight-threatening complications. Due to the role of awareness, self-examination, and preventive behavior in prevention of morbidity of high myopia complications, promoting knowledge, capabilities, and attitude of high myopic personnel are required in this regard. In this quasi-experiment study, 31 freshmen with high myopia in a national university were enrolled in 2014. The data were collected by validated and reliable questionnaire based on health belief model (HBM) and self-efficacy theory. The intervention program consisted of 1 educational session lasting 150 minutes by lecturing of high myopia complications, virtual reality experiencing, similarity modeling, and quibbling a film made on high myopia complications preventive concepts. Implementing the educational program showed immediate effect in knowledge, perceived susceptibility, perceived severity, self-efficacy, and preventive behavior intention. While 6 weeks after the educational program, significant increases were observed in cues to action, self-efficacy, and preventive behavior intention. This article provided that, after a single session, there was positive improvement in high myopia complication prevention behavior intention among participants. These positive effects confirmed the efficacy of the education program and will probably induce behavior change. PMID:27749586

Evaluation of high myopia complications prevention program in university freshmen.

PubMed

Tseng, Gow-Lieng; Chen, Cheng-Yu

2016-10-01

High myopia is a global eye health problem because of its high incidence of sight-threatening complications. Due to the role of awareness, self-examination, and preventive behavior in prevention of morbidity of high myopia complications, promoting knowledge, capabilities, and attitude of high myopic personnel are required in this regard.In this quasi-experiment study, 31 freshmen with high myopia in a national university were enrolled in 2014. The data were collected by validated and reliable questionnaire based on health belief model (HBM) and self-efficacy theory. The intervention program consisted of 1 educational session lasting 150 minutes by lecturing of high myopia complications, virtual reality experiencing, similarity modeling, and quibbling a film made on high myopia complications preventive concepts.Implementing the educational program showed immediate effect in knowledge, perceived susceptibility, perceived severity, self-efficacy, and preventive behavior intention. While 6 weeks after the educational program, significant increases were observed in cues to action, self-efficacy, and preventive behavior intention.This article provided that, after a single session, there was positive improvement in high myopia complication prevention behavior intention among participants. These positive effects confirmed the efficacy of the education program and will probably induce behavior change.

Effect of dual-focus soft contact lens wear on axial myopia progression in children.

PubMed

Anstice, Nicola S; Phillips, John R

2011-06-01

To test the efficacy of an experimental Dual-Focus (DF) soft contact lens in reducing myopia progression. Prospective, randomized, paired-eye control, investigator-masked trial with cross-over. Forty children, 11-14 years old, with mean spherical equivalent refraction (SER) of -2.71 ± 1.10 diopters (D). Dual-Focus lenses had a central zone that corrected refractive error and concentric treatment zones that created 2.00 D of simultaneous myopic retinal defocus during distance and near viewing. Control was a single vision distance (SVD) lens with the same parameters but without treatment zones. Children wore a DF lens in 1 randomly assigned eye and an SVD lens in the fellow eye for 10 months (period 1). Lens assignment was then swapped between eyes, and lenses were worn for a further 10 months (period 2). Primary outcome was change in SER measured by cycloplegic autorefraction over 10 months. Secondary outcome was a change in axial eye length (AXL) measured by partial coherence interferometry over 10 months. Accommodation wearing DF lenses was assessed using an open-field autorefractor. In period 1, the mean change in SER with DF lenses (-0.44 ± 0.33 D) was less than with SVD lenses (-0.69 ± 0.38 D; P < 0.001); mean increase in AXL was also less with DF lenses (0.11 ± 0.09 mm) than with SVD lenses (0.22 ± 0.10 mm; P < 0.001). In 70% of the children, myopia progression was reduced by 30% or more in the eye wearing the DF lens relative to that wearing the SVD lens. Similar reductions in myopia progression and axial eye elongation were also observed with DF lens wear during period 2. Visual acuity and contrast sensitivity with DF lenses were not significantly different than with SVD lenses. Accommodation to a target at 40 cm was driven through the central distance-correction zone of the DF lens. Dual-Focus lenses provided normal acuity and contrast sensitivity and allowed accommodation to near targets. Myopia progression and eye elongation were reduced significantly in eyes wearing DF lenses. The data suggest that sustained myopic defocus, even when presented to the retina simultaneously with a clear image, can act to slow myopia progression without compromising visual function. Proprietary or commercial disclosure may be found after the references. Copyright © 2011 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Refractive Errors in 3–6 Year-Old Chinese Children: A Very Low Prevalence of Myopia?

PubMed Central

Lin, Lixia; Li, Zhen; Zeng, Junwen; Yang, Zhikuan; Morgan, Ian G.

2013-01-01

Purpose To examine the prevalence of refractive errors in children aged 3–6 years in China. Methods Children were recruited for a trial of a home-based amblyopia screening kit in Guangzhou preschools, during which cycloplegic refractions were measured in both eyes of 2480 children. Cycloplegic refraction (from 3 to 4 drops of 1% cyclopentolate to ensure abolition of the light reflex) was measured by both autorefraction and retinoscopy. Refractive errors were defined as followed: myopia (at least −0.50 D in the worse eye), hyperopia (at least +2.00 D in the worse eye) and astigmatism (at least 1.50 D in the worse eye). Different definitions, as specified in the text, were also used to facilitate comparison with other studies. Results The mean spherical equivalent refractive error was at least +1.22 D for all ages and both genders. The prevalence of myopia for any definition at any age was at most 2.5%, and lower in most cases. In contrast, the prevalence of hyperopia was generally over 20%, and declined slightly with age. The prevalence of astigmatism was between 6% and 11%. There was very little change in refractive error with age over this age range. Conclusions Previous reports of less hyperopic mean spherical equivalent refractive error, and more myopia and less hyperopia in children of this age may be due to problems with achieving adequate cycloplegia in children with dark irises. Using up to 4 drops of 1% cyclopentolate may be necessary to accurately measure refractive error in paediatric studies of such children. Our results suggest that children from all ethnic groups may follow a similar pattern of early refractive development, with little myopia and a hyperopic mean spherical equivalent over +1.00 D up to the age of 5–6 yearsin most conditions. PMID:24205064

Academic achievement, close up work parameters, and myopia in Singapore military conscripts

PubMed Central

Saw, S.; Wu, H.; Seet, B.; Wong, T.; Yap, E.; Chia, K.; Stone, R.; Lee, L.

2001-01-01

AIM—To determine the relation of refractive error to environmental factors, including close up work, in Singapore military conscripts.
METHODS—A cross sectional study was conducted on 429 Singapore military conscripts. Non-cycloplegic refraction and A-scan biometry were performed in both eyes. A detailed questionnaire was administered by in-person interview to obtain information about current and past near work activity, extra tuition lessons, educational experiences, and family demographics.
RESULTS—Myopia associated with the conscript having been educated in the (gifted, special, or express) educational streams (adjusted odds ratio (OR) = 3.8, 95% confidence interval CI 2.0-7.3), and having completed pre-university education (OR=4.1, 95% CI 1.9-8.8). The reported close up work activity at age 7 years did correlate with age of onset of myopia (p<0.001). In parallel, supplemental tuition lessons in primary school has (OR=2.6, 95% CI 1.4-4.9) associated with conscript myopia. Parental myopia was positively associated with myopia (p<0.001), but this relation disappeared when adjusted for environmental factors. Current (p=0.83) and past close up work activity at age 7 years (p=0.13) did not correlate with myopia.
CONCLUSION—Educational level and educational stream positively related to myopia. A relation was observed with reported close up work activity in early childhood and with tuition classes during elementary school, but not with current close up work activity. These results underscore the strong influence of environment in myopia pathogenesis but a role for close up work activity remains indeterminate.

 PMID:11423462

Disordered Sleep and Myopia Risk among Chinese Children

PubMed Central

Zhou, Zhongqiang; Morgan, Ian G.; Chen, Qianyun; Jin, Ling; He, Mingguang; Congdon, Nathan

2015-01-01

Purpose Disordered sleep and myopia are increasingly prevalent among Chinese children. Similar pathways may be involved in regulation of both sleep cycles and eye growth. We therefore sought to examine the association between disordered sleep and myopia in this group. Methods Urban primary school children participating in a clinical trial on myopia and outdoor activity underwent automated cycloplegic refraction with subjective refinement. Parents answered questions about children's sleep duration, sleep disorders (Children's Sleep Habits Questionnaire [CSHQ]), near work and time spent outdoors. Results Among 1970 children, 1902 (96.5%, mean [standard deviation SD] age 9.80 [0.44] years, 53.1% boys) completed refraction and questionnaires. Myopia < = -0.50 Diopters was present in both eyes of 588 (30.9%) children (1329/3804 = 34.9% of eyes) and 1129 children (59.4%) had abnormal CSHQ scores (> 41). In logistic regression models by eye, odds of myopia < = -0.50D increased with worse CSHQ score (Odds Ratio [OR] 1.01 per point, 95% Confidence Interval [CI] [1.001, 1.02], P = 0.014) and more night-time sleep (OR 1.02, 95% CI [1.01, 1.04, P = 0.002], while male sex (OR 0.82, 95% CI [0.70, 0.95], P = 0.008) and time outdoors (OR = 0.97, 95% CI [0.95, 0.99], P = 0.011) were associated with less myopia. The association between sleep duration and myopia was not significant (p = 0.199) for total (night + midday) sleep. Conclusions Myopia and disordered sleep were both common in this cohort, but we did not find consistent evidence for an association between the two. Trial Registration clinicaltrials.gov NCT00848900 PMID:25811755

Five-Year Progression of Refractive Errors and Incidence of Myopia in School-Aged Children in Western China

PubMed Central

Zhou, Wen-Jun; Zhang, Yong-Ye; Li, Hua; Wu, Yu-Fei; Xu, Ji; Lv, Sha; Li, Ge; Liu, Shi-Chun; Song, Sheng-Fang

2016-01-01

Background To determine the change in refractive error and the incidence of myopia among school-aged children in the Yongchuan District of Chongqing City, Western China. Methods A population-based cross-sectional survey was initially conducted in 2006 among 3070 children aged 6 to 15 years. A longitudinal follow-up study was then conducted 5 years later between November 2011 and March 2012. Refractive error was measured under cycloplegia with autorefraction. Age, sex, and baseline refractive error were evaluated as risk factors for progression of refractive error and incidence of myopia. Results Longitudinal data were available for 1858 children (60.5%). The cumulative mean change in refractive error was −2.21 (standard deviation [SD], 1.87) diopters (D) for the entire study population, with an annual progression of refraction in a myopic direction of −0.43 D. Myopic progression of refractive error was associated with younger age, female sex, and higher myopic or hyperopic refractive error at baseline. The cumulative incidence of myopia, defined as a spherical equivalent refractive error of −0.50 D or more, among initial emmetropes and hyperopes was 54.9% (95% confidence interval [CI], 45.2%–63.5%), with an annual incidence of 10.6% (95% CI, 8.7%–13.1%). Myopia was found more likely to happen in female and older children. Conclusions In Western China, both myopic progression and incidence of myopia were higher than those of children from most other locations in China and from the European Caucasian population. Compared with a previous study in China, there was a relative increase in annual myopia progression and annual myopia incidence, a finding which is consistent with the increasing trend on prevalence of myopia in China. PMID:26875599

Five-Year Progression of Refractive Errors and Incidence of Myopia in School-Aged Children in Western China.

PubMed

Zhou, Wen-Jun; Zhang, Yong-Ye; Li, Hua; Wu, Yu-Fei; Xu, Ji; Lv, Sha; Li, Ge; Liu, Shi-Chun; Song, Sheng-Fang

2016-07-05

To determine the change in refractive error and the incidence of myopia among school-aged children in the Yongchuan District of Chongqing City, Western China. A population-based cross-sectional survey was initially conducted in 2006 among 3070 children aged 6 to 15 years. A longitudinal follow-up study was then conducted 5 years later between November 2011 and March 2012. Refractive error was measured under cycloplegia with autorefraction. Age, sex, and baseline refractive error were evaluated as risk factors for progression of refractive error and incidence of myopia. Longitudinal data were available for 1858 children (60.5%). The cumulative mean change in refractive error was -2.21 (standard deviation [SD], 1.87) diopters (D) for the entire study population, with an annual progression of refraction in a myopic direction of -0.43 D. Myopic progression of refractive error was associated with younger age, female sex, and higher myopic or hyperopic refractive error at baseline. The cumulative incidence of myopia, defined as a spherical equivalent refractive error of -0.50 D or more, among initial emmetropes and hyperopes was 54.9% (95% confidence interval [CI], 45.2%-63.5%), with an annual incidence of 10.6% (95% CI, 8.7%-13.1%). Myopia was found more likely to happen in female and older children. In Western China, both myopic progression and incidence of myopia were higher than those of children from most other locations in China and from the European Caucasian population. Compared with a previous study in China, there was a relative increase in annual myopia progression and annual myopia incidence, a finding which is consistent with the increasing trend on prevalence of myopia in China.

Time Outdoors at Specific Ages During Early Childhood and the Risk of Incident Myopia

PubMed Central

Shah, Rupal L.; Huang, Yu; Guggenheim, Jeremy A.; Williams, Cathy

2017-01-01

Purpose Time outdoors during childhood is negatively associated with incident myopia. Consequently, additional time outdoors has been suggested as a public health intervention to reduce the prevalence of myopia. We investigated whether there were specific ages during early childhood when the time outdoors versus incident myopia association was strongest. Methods Children participating in the Avon Longitudinal Study of Parents and Children (ALSPAC) were studied from age 2 to 15 years. Parentally reported time outdoors and time spent reading were assessed longitudinally in early childhood (ages 2, 3, 4, 5, 7, and 9 years). Noncycloplegic autorefraction was carried out longitudinally in later childhood (ages 10, 11, 12, and 15 years). Information was available for 2833 participants. Cox proportional hazards regression was used to test for association between time outdoors and incident myopia. Results From 3 years of age onward, greater time outdoors was associated with a reduced risk of incident myopia. The hazard ratio for myopia changed progressively from 0.90 (95% CI 0.83–0.98, P = 0.012) at age 3 years, to 0.86 (95% CI 0.78–0.93, P = 0.001) at age 9 years, for each additional SD of time spent outdoors per day. These associations were independent of two major risk factors for myopia: time reading and number of myopic parents. Conclusions Additional time spent outdoors across the 3 to 9 years age range was associated with a reduced incidence of myopia between ages 10 and 15 years. There was a trend for the association to increase toward the older end of the 3 to 9 years range. PMID:28245296

Botulinum toxin for treatment of restrictive strabismus.

PubMed

Merino, Pilar S; Vera, Rebeca E; Mariñas, Laura G; Gómez de Liaño, Pilar S; Escribano, Jose V

To study the types of acquired restrictive strabismus treated in a tertiary hospital and the outcome of treatment with botulinum toxin. We performed a 10-year retrospective study of patients with restrictive strabismus aged ≥18 years who were treated with botulinum toxin. Treatment was considered successful if the final vertical deviation was ≤5 PD, horizontal deviation ≤10 PD, with no head turn or diplopia. We included 27 cases (mean age, 61.9 years). Horizontal strabismus was diagnosed in 11.1%, vertical in 51.9%, and mixed in 37%. Strabismus was secondary to cataract surgery in 6 cases, high myopia in 6, orbital fractures in 5, retinal surgery in 5, Graves ophthalmopathy in 4, and repair of conjunctival injury in 1 case. Diplopia was diagnosed in all patients, head turn in 33.3%. The initial deviation was 14 PD (range, 2-40), the mean number of injections per patient was 1.6 (range, 1-3), and the mean dose was 9.5 IU (range, 2.5-22.5). At the end of follow-up, diplopia was recorded in 59.3%, head turn in 18.5%, surgical treatment in 51.9%, and need for prism glasses in 14.8%. Outcome was successful in 37% of patients (4 high myopia, 3 orbital fractures, 2 post-surgical retinal detachment, and 1 post-cataract surgery). Mean follow-up was 3±1.8 years. Vertical deviation was observed in half of the sample. The most frequent deviation was secondary to cataract surgery and high myopia. Treatment with botulinum toxin was successful in one-third of the patients at the end of follow-up. Copyright © 2016 Spanish General Council of Optometry. Published by Elsevier España, S.L.U. All rights reserved.

PDT: special cases in front of legal regulations

NASA Astrophysics Data System (ADS)

Fischer, E.; Wegner, A.; Pfeiler, T.; Mertz, M.

2002-10-01

Introduction: The classic indication for photodynamic therapy (PDT) in ophthalmology is currently represented by classic subfoveal choroidal neovascularisation (CNV) due to age-related macular degeneration (AMD). PDT is a method, which almost selectively causes endothelial damage in neovascular lesions, followed by vascular occlusion and involution of the CNV. The mechanistic aspect suggests that non AMD-related choroidal neovascularisations might also benefit from PDT. PDT in AMD: Within the German health system, PDT indications follow the criteria based on the inclusion criteria of the TAP studies. For instance the CNV should be predominantly classic and located under the center of the foveal avascular zone. In the diagnosis and follow-up of exudative AMD, visual acuity measurements and fluorescein angiography are the established parameters. Retinal thickness analyzer (RTA) measurements might give further information. Before PDT, they show a significant retinal thickening due to intra- and subretinal exudation. Following PDT, early RTA follow-ups show a clear decrease in retinal thickening accompanies by increasing or stable acuity. PDT in CNV of other origins than AMD: New studies support a new spectrum of indications for PDT, hopefully leading to general cost reimbursement for patients. PDT should be viewed as a general method for vascular occlusion and does not represent a causal therapy for progressive exudative AMD. We present patients with CNV due to pathologic myopia, angioid streaks and POHS. Conclusion: The selective vascular occlusion caused by PDT, besides CNV associated with AMD and pathologic myopia, may also allow the treatment of choroidal neovascularisations based on other entities. Careful individual evaluation of those cases is recommended. Despite this wide array of possible indications, cost reimbursement has been limited to classic subfoveal CNV in AMD, although single case reimbursements in choroidal neovascular lesions due to pathologic myopia have been observed.

Improvement of uncorrected visual acuity and contrast sensitivity with perceptual learning and transcranial random noise stimulation in individuals with mild myopia

PubMed Central

Camilleri, Rebecca; Pavan, Andrea; Ghin, Filippo; Battaglini, Luca; Campana, Gianluca

2014-01-01

Perceptual learning has been shown to produce an improvement of visual acuity (VA) and contrast sensitivity (CS) both in subjects with amblyopia and refractive defects such as myopia or presbyopia. Transcranial random noise stimulation (tRNS) has proven to be efficacious in accelerating neural plasticity and boosting perceptual learning in healthy participants. In this study, we investigated whether a short behavioral training regime using a contrast detection task combined with online tRNS was as effective in improving visual functions in participants with mild myopia compared to a 2-month behavioral training regime without tRNS (Camilleri et al., 2014). After 2 weeks of perceptual training in combination with tRNS, participants showed an improvement of 0.15 LogMAR in uncorrected VA (UCVA) that was comparable with that obtained after 8 weeks of training with no tRNS, and an improvement in uncorrected CS (UCCS) at various spatial frequencies (whereas no UCCS improvement was seen after 8 weeks of training with no tRNS). On the other hand, a control group that trained for 2 weeks without stimulation did not show any significant UCVA or UCCS improvement. These results suggest that the combination of behavioral and neuromodulatory techniques can be fast and efficacious in improving sight in individuals with mild myopia. PMID:25400610

[The long-term clinical effects of orthokeratology in high myopia children].

PubMed

Zhou, Jianlan; Xie, Peiying; Wang, Dan; Guo, Xi; Yang, Lina

2015-07-01

To investigate the long-term clinical effects of orthokeratology (ortho-k) in high myopia children with 5 years of follow-ups. Prospective study. We chose 30 high myopia patients to wear ortho-k contact lenses (CLs) for controlling or delaying myopia progression from 2003. Among them, there were 10 boys and 20 girls whose average age was (15 ± 2) years, spherical diopters were (-7.34 ± 0.91) D, corneal astigmatism diopters were (-1.06 ± 0.62) D, uncorrected visual acuity was LogMAR 0.89 ± 0.29, corneal flattened curvature was (43.54 ± 1.16) D, and axial length was (26.38 ± 0.94) mm. All patients, with informed consent before fitting of ortho-k CLs, had conventional refraction and ocular tests. We compared the values of spherical diopters, visual acuity, corneal flattened curvature and axial length before and 6 months, 1 year, 2 years, 3 years, 4 years and 5 years after wearing CLs, respectively. The results were analyzed by SPSS 16.0 software. During the five years of observation periods, all patients' visual acuity and corneal flattened curvature were different from the pre-fitting (P < 0.05). Compared to the pre-fitting, the naked visual acuity was some degree improved, it was LogMAR 0.45 ± 0.31, 0.49 ± 0.32, 0.43 ± 0.30, 0.47 ± 0.31, 0.58 ± 0.35, 0.53 ± 0.27, respectively. F = 10.725, P = 0.000. Corneal flatten curvature was tend to be flatter, such was 41.14 ± 1.54, 41.75 ± 1.88, 41.54 ± 2.10, 41.73 ± 1.89, 41.94 ± 1.61, 40.70 ± 1.67. F = 10.161, P = 0.000 (All P < 0.05). The spherical diopters during the first two years after wearing ortho-k CLs were significantly reduced, compared with the previous values (it was -5.23 ± 1.81, -5.59 ± 2.75, -6.29 ± 2.12, -6.63 ± 2.31, -6.83 ± 2.33, -7.01 ± 1.81, respectively, F = 4.929, P = 0.000), and kept stable in the long-term observation. The axial length checked at 5 years was slightly elongated (it was 26.41 ± 0.90, 26.68 ± 0.93, 26.69 ± 1.06, 26.75 ± 0.94, 26.81 ± 1.04, 27.04 ± 1.01. F = 1.831, P = 0.094). The axial elongation was retarded by using ortho-k CLs in high myopia children. All patients were not subjected to severe complications which may lead to quitting the enrollments. Orthokeratology used in controlling or delaying high myopia progression is definitely outstanding in 5 years observations. Standard lens wearing and regular lens check improve safety of lens use in high myopia.

A cluster randomised controlled trial evaluating an incentive-based outdoor physical activity programme to increase outdoor time and prevent myopia in children.

PubMed

Ngo, Cheryl S; Pan, Chen-Wei; Finkelstein, Eric A; Lee, Chun-Fan; Wong, Inez B; Ong, Julia; Ang, Marcus; Wong, Tien-Yin; Saw, Seang-Mei

2014-05-01

To evaluate an incentive-based intervention to increase time spent outdoors among children in a 9-month cluster randomised controlled trial. Two hundred and eighty-five children aged 6-12 years of age were randomised to the intervention (n = 147) or control arm (n = 138) in the Family incentive trial (FIT). The FIT intervention comprised of targeted education on myopia and good eye care habits, structured weekend outdoor activities and incentives for children to increase their daily steps via pedometers. The main outcome measure was outdoor time, measured by the WHO questionnaire and a 1-week diary. Interim analysis at 6 months showed a significant increase in mean outdoor time per week in the intervention arm (14.75 h week(-1) ) compared to the control arm (12.40 h week(-1) ) as measured by the questionnaire (p = 0.04). However, greater outdoor time was not statistically significant at the end of the trial (15.95 h week(-1) vs 14.34 h in the control group (p = 0.29). There was an increase in outdoor time for children in the incentive-based physical activity outdoor program after 6 months but not at the end of the trial. Further larger school trials with better compliance with the intervention and longer duration could be conducted to evaluate clinical outcomes such as myopic shifts. © 2014 The Authors Ophthalmic & Physiological Optics © 2014 The College of Optometrists.

The Adenosine Receptor Antagonist, 7-Methylxanthine, Alters Emmetropizing Responses in Infant Macaques

PubMed Central

Hung, Li-Fang; Arumugam, Baskar; Ostrin, Lisa; Patel, Nimesh; Trier, Klaus; Jong, Monica; III, Earl L. Smith

2018-01-01

Purpose Previous studies suggest that the adenosine receptor antagonist, 7-methylxanthine (7-MX), retards myopia progression. Our aim was to determine whether 7-MX alters the compensating refractive changes produced by defocus in rhesus monkeys. Methods Starting at age 3 weeks, monkeys were reared with −3 diopter (D; n = 10; 7-MX −3D/pl) or +3D (n = 6; 7-MX +3D/pl) spectacles over their treated eyes and zero-powered lenses over their fellow eyes. In addition, they were given 100 mg/kg of 7-MX orally twice daily throughout the lens-rearing period (age 147 ± 4 days). Comparison data were obtained from lens-reared controls (−3D/pl, n = 17; +3D/pl, n = 9) and normal monkeys (n = 37) maintained on a standard diet. Refractive status, corneal power, and axial dimensions were assessed biweekly. Results The −3D/pl and +3D/pl lens-reared controls developed compensating myopic (−2.10 ± 1.07 D) and hyperopic anisometropias (+1.86 ± 0.54 D), respectively. While the 7-MX +3D/pl monkeys developed hyperopic anisometropias (+1.79 ± 1.11 D) that were similar to those observed in +3D/pl controls, the 7-MX −3D/pl animals did not consistently exhibit compensating myopia in their treated eyes and were on average isometropic (+0.35 ± 1.96 D). The median refractive errors for both eyes of the 7-MX −3D/pl (+5.47 D and +4.38 D) and 7-MX +3D/pl (+5.28 and +3.84 D) monkeys were significantly more hyperopic than that for normal monkeys (+2.47 D). These 7-MX–induced hyperopic ametropias were associated with shorter vitreous chambers and thicker choroids. Conclusions In primates, 7-MX reduced the axial myopia produced by hyperopic defocus, augmented hyperopic shifts in response to myopic defocus, and induced hyperopia in control eyes. The results suggest that 7-MX has therapeutic potential in efforts to slow myopia progression. PMID:29368006

Refractive eye surgery in treating functional amblyopia in children.

PubMed

Levenger, Samuel; Nemet, Pinhas; Hirsh, Ami; Kremer, Israel; Nemet, Arie

2006-01-01

While excimer laser refractive surgery is recommended and highly successful for correcting refractive errors in adults, its use in children has not been extensively exercised or studied. We report our experience treating children with amblyopia due to high anisometropia, high astigmatism, high myopia and with associated developmental delay. Review of patient records of our refractive clinic. A retrospective review was made of all 11 children with stable refractive errors who were unsuccessfully treated non-surgically and then underwent corneal refractive surgery and in one case, lenticular surgery. Seven had high myopic anisometropia, 2 had high astigmatism, and two had high myopia--one with Down's Syndrome and one with agenesis of the corpus callosum. The surgical refractive treatment eliminated or reduced the anisometropia, reduced the astigmatic error, improved vision and improved the daily function of the children with developmental delay. There were no complications or untoward results. Refractive surgery is safe and effective in treating children with high myopic anisometropia, high astigmatism, high myopia and developmental delay due to the resulting poor vision. Surgery can improve visual acuity in amblyopia not responding to routine treatment by correcting the refractive error and refractive aberrations.

Myopia prevention and therapy. The role of pharmaceutical agents. Japanese studies.

PubMed

Hosaka, A

1988-01-01

In order to normalize the condition of pseudomyopia, the following can be summarized: One percent cyclopentolate was effective in 63%, and 0.4% tropicamide was effective in 59% of the cases. With a value of 68% after labetalol eye drops there were no significant differences in efficacy between this drug and the above cycloplegics. In subjects treated only with placebo, 4 out of 16 eyes, i.e. 25% were relieved. A significant difference (P less than 0.01) was found between the results with the above 3 drugs and placebo. On the other hand, the efficacy of 0.25% timolol (effect in 28%) and chemical X (effect in 37%) were not significantly different from the effect of placebo, though the results with chemical X encourage further trials. It can be postulated that by releasing an abnormal tension cycloplegics reduce the myopic condition. Regarding the hypotensive action of beta-adrenergic blockers on intraocular pressure, it presumably depends mainly on inhibition of secretion in the ciliary body. The fact that labetalol appeared effective, and timolol not, in treatment trials of slight myopia might imply that the mechanism behind an effect of labetalol on slight myopia is not merely a beta-adrenergic blocking action.

The Charles F. Prentice Award Lecture 2010: A Case for Peripheral Optical Treatment Strategies for Myopia

PubMed Central

Smith, Earl L.

2011-01-01

It is well established that refractive development is regulated by visual feedback. However, most optical treatment strategies designed to reduce myopia progression have not produced the desired results, primarily because some of our assumptions concerning the operating characteristics of the vision-dependent mechanisms that regulate refractive development have been incorrect. In particular, because of the prominence of central vision in primates, it has generally been assumed that signals from the fovea determine the effects of vision on refractive development. However, experiments in laboratory animals demonstrate that ocular growth and emmetropization are mediated by local retinal mechanisms and that foveal vision is not essential for many vision-dependent aspects of refractive development. On the other hand, the peripheral retina, in isolation, can effectively regulate emmetropization and mediate many of the effects of vision on the eye’s refractive status. Moreover, when there are conflicting visual signals between the fovea and the periphery, peripheral vision can dominate refractive development. The overall pattern of results suggests that optical treatment strategies for myopia that take into account the effects of peripheral vision are likely to be more successful than strategies that effectively manipulate only central vision. PMID:21747306

[Fluorescein angiography and optical coherence tomography findings in central fundus of myopic patients].

PubMed

Avetisov, S E; Budzinskaya, M V; Zhabina, O A; Andreeva, I V; Plyukhova, A A; Kobzova, M V; Musaeva, G M

2015-01-01

Myopia prevalence grows alike in many countries, including Russia, regardless of geographical and population conditions. to assess fundus changes in myopic patients at different ocular axial lengths by means of modern diagnostic tools. The study enrolled 97 patients (194 eyes) aged 45 ± 20.17 years with myopia of different degrees. Besides a standard ophthalmic examination, all patients underwent fundus fluorescein angiography and optical coherence tomography. The occurrence of retinal pigment epithelium (RPE) atrophy (diffuse or focal) has been shown to increase with increasing ocular axial length. Only 27 eyes (28.1%) appeared intact. As myopia progression implies axial growth of the eye, it is associated with a more severe decrease in choroid, RPE, and photoreceptor layer thicknesses: the longer the anterior-posterior axis, the thinner the above mentioned fundus structures. Age-related changes in the fundus are also likely to be more pronounced in longer axes. Myopic traction maculopathy, which in our case appeared the main cause of increased retinal thickness, was diagnosed in 105 eyes, "outer" macular retinoschisis--in 40 eyes. Thus, modern diagnostic tools, such as fluorescein angiography and optical coherence tomography, enable objective assessment of the central fundus.

The Rat With Oxygen-Induced Retinopathy Is Myopic With Low Retinal Dopamine

PubMed Central

Zhang, Nan; Favazza, Tara L.; Baglieri, Anna Maria; Benador, Ilan Y.; Noonan, Emily R.; Fulton, Anne B.; Hansen, Ronald M.; Iuvone, P. Michael; Akula, James D.

2013-01-01

Purpose. Dopamine (DA) is a neurotransmitter implicated both in modulating neural retinal signals and in eye growth. Therefore, it may participate in the pathogenesis of the most common clinical sequelae of retinopathy of prematurity (ROP), visual dysfunction and myopia. Paradoxically, in ROP myopia the eye is usually small. The eye of the rat with oxygen-induced retinopathy (OIR) is characterized by retinal dysfunction and short axial length. There have been several investigations of the early maturation of DA in rat retina, but little at older ages, and not in the OIR rat. Therefore, DA, retinal function, and refractive state were investigated in the OIR rat. Methods. In one set of rats, the development of dopaminergic (DAergic) networks was evaluated in retinal cross-sections from rats aged 14 to 120 days using antibodies against tyrosine hydroxylase (TH, the rate-limiting enzyme in the biosynthesis of DA). In another set of rats, retinoscopy was used to evaluate spherical equivalent (SE), electoretinography (ERG) was used to evaluate retinal function, and high-pressure liquid chromatography (HPLC) was used to evaluate retinal contents of DA, its precursor levodopamine (DOPA), and its primary metabolite 3,4-dihydroxyphenylacetic acid (DOPAC). Results. The normally rapid postnatal ramification of DAergic neurons was disrupted in OIR rats. Retinoscopy revealed that OIR rats were relatively myopic. In the same eyes, ERG confirmed retinal dysfunction in OIR. HPLC of those eyes' retinae confirmed low DA. Regression analysis indicated that DA metabolism (evaluated by the ratio of DOPAC to DA) was an important additional predictor of myopia beyond OIR. Conclusions. The OIR rat is the first known animal model of myopia in which the eye is smaller than normal. Dopamine may modulate, or fail to modulate, neural activity in the OIR eye, and thus contribute to this peculiar myopia. PMID:24168993

The rat with oxygen-induced retinopathy is myopic with low retinal dopamine.

PubMed

Zhang, Nan; Favazza, Tara L; Baglieri, Anna Maria; Benador, Ilan Y; Noonan, Emily R; Fulton, Anne B; Hansen, Ronald M; Iuvone, P Michael; Akula, James D

2013-12-19

Dopamine (DA) is a neurotransmitter implicated both in modulating neural retinal signals and in eye growth. Therefore, it may participate in the pathogenesis of the most common clinical sequelae of retinopathy of prematurity (ROP), visual dysfunction and myopia. Paradoxically, in ROP myopia the eye is usually small. The eye of the rat with oxygen-induced retinopathy (OIR) is characterized by retinal dysfunction and short axial length. There have been several investigations of the early maturation of DA in rat retina, but little at older ages, and not in the OIR rat. Therefore, DA, retinal function, and refractive state were investigated in the OIR rat. In one set of rats, the development of dopaminergic (DAergic) networks was evaluated in retinal cross-sections from rats aged 14 to 120 days using antibodies against tyrosine hydroxylase (TH, the rate-limiting enzyme in the biosynthesis of DA). In another set of rats, retinoscopy was used to evaluate spherical equivalent (SE), electoretinography (ERG) was used to evaluate retinal function, and high-pressure liquid chromatography (HPLC) was used to evaluate retinal contents of DA, its precursor levodopamine (DOPA), and its primary metabolite 3,4-dihydroxyphenylacetic acid (DOPAC). The normally rapid postnatal ramification of DAergic neurons was disrupted in OIR rats. Retinoscopy revealed that OIR rats were relatively myopic. In the same eyes, ERG confirmed retinal dysfunction in OIR. HPLC of those eyes' retinae confirmed low DA. Regression analysis indicated that DA metabolism (evaluated by the ratio of DOPAC to DA) was an important additional predictor of myopia beyond OIR. The OIR rat is the first known animal model of myopia in which the eye is smaller than normal. Dopamine may modulate, or fail to modulate, neural activity in the OIR eye, and thus contribute to this peculiar myopia.

Early Intervention and Nonpharmacological Therapy of Myopia in Young Adults

PubMed Central

Gładysiak, Aleksandra; Ślęzak, Daniel

2018-01-01

Myopia is a condition of the eye where parallel rays focus in front of, instead of on, the retina, which results in excessive refractive power of the cornea or the lens or eyeball elongation. Studies carried out in recent years show that the etiology of myopia is complex with genetic and environmental factors playing a role. Refraction defects decrease the quality of vision, while progressing myopia can lead to partial loss of vision, which can be particularly dramatic in young adults. Therefore, it is so crucial to take appropriate actions aimed at preventing myopia progression. This is a review of nonpharmacological therapeutic possibilities of refraction defect prevention in young adults, with special regard to myofascial therapy, osteopathy, and massage of acupuncture points surrounding the eye. PMID:29576878

A clinical study on the role of Akshi Tarpana with Jeevantyadi Ghrita in Timira (Myopia).

PubMed

Poonam; Manjusha, R; Vaghela, D B; Shukla, V J

2011-10-01

Myopia is a major public health problem pertaining to eye that entails substantial societal, personal, educational, and economical impact. Various surveys in India have found the prevalence of myopia ranging from 6.9% to 19.7%. Myopia progression is irreversible and methods for the correction of myopia are not without complications. Myopia closely resembles Timira involving first and second Patala in terms of symptoms, anatomical structures involved, and the pathogenesis of the disease. The study is aimed at evaluating the efficacy of the Akshi-Tarpana procedure with Jeevantyadi Ghrita in fresh and old myopes. A total of 54 patients (108 eyes) having myopia ≥-6 D were registered for the study and divided into two groups (Group A, Akshi-Tarpana with Jeevantyadi Ghrita, and Group B, Akshi-Tarpana with plain Go Ghrita), by stratified sampling. The procedure was done in 5 sittings of 5 days each with an equal interval of 5 days between each sitting. A total of 22 patients in Group A and 18 in Group B completed the treatment. Obtained data were statistically analyzed using a t-test and the study reveals that objectively, 09.30% and 05.55% eyes were cured, 16.28% and 02.78% markedly improved, and 34.88% and 11.11% moderately improved in Group A and B, respectively.

Refractive errors in a rural Chinese adult population the Handan eye study.

PubMed

Liang, Yuan Bo; Wong, Tien Yin; Sun, Lan Ping; Tao, Qiu Shan; Wang, Jie Jin; Yang, Xiao Hui; Xiong, Ying; Wang, Ning Li; Friedman, David S

2009-11-01

To describe the prevalence of and risk factors for myopia and other refractive errors in a rural, adult, Chinese population. Population-based, cross-sectional study. A clustered, random sampling procedure was used to select 7557 Chinese people aged >or=30 years from Handan, China. All eligible subjects were invited to undergo a comprehensive eye examination, including standardized refraction. Myopia, high myopia, and hyperopia were defined as a spherical equivalent (SE) in the right eye of more than -0.5 diopter (D), less than -5.0 D, and 0.5 D or more, respectively. Astigmatism was less than -0.5 D of cylinder. Anisometropia was defined as a difference in SE of >1.0 D between the 2 eyes. Only phakic eyes were analyzed. Myopia and other refractive errors. We included 6491 (85.9% participation rate) eligible subjects in this study. Adjusted to the 2000 China population census, the prevalence rate of myopia was 26.7% (95% confidence interval [CI], 25.6-27.8), hyperopia 15.9 % (95% CI, 15.0-16.8), astigmatism 24.5% (95% CI, 23.5-25.5), and anisometropia 7.7% (95% CI, 7.0-8.4). The prevalence of high myopia was 1.8% (95% CI, 1.5-2.1). Using a multivariate regression model, current smoking (odds ratio [OR], 0.7, 95% CI, 0.5-0.9), hours of reading (OR, 1.2; 95% CI, 1.1-1.4), diabetes (OR, 8.4; 95% CI, 2.2-32.5), and number of family members with myopia (OR, 1.3; 95% CI, 1.1-1.7, for each family member) were associated with myopia in younger persons (30-49 years). High school or higher education (OR, 1.8; 95% CI, 1.1-3.1), diabetes (OR, 1.6; 95% CI, 1.2-2.7), nuclear opacity (OR, 1.7; 95% CI, 1.2-2.3), and number of family members with myopia (OR, 1.5; 95% CI, 1.2-1.9) were risk factors in persons >or=50 years of age. Myopia affects more than one quarter of rural Chinese persons >or=30 years of age. Myopia is more common in younger people and is associated with different risk factors than in older people.

Photorefractive keratectomy in young Asian aviators with low-moderate myopia.

PubMed

See, Brian; Tan, Marcus; Chia, Sin Eng; Gan, Wee Hoe; Low, Robin; Nah, Gerard

2014-01-01

The high prevalence of myopia among Asians led the Republic of Singapore Air Force (RSAF) to introduce photorefractive keratectomy (PRK) as a means of enlarging its pilot recruitment pool at the end of 2005. This study aims to address the efficacy and safety of PRK performed on young Asian patients with low-moderate myopia, as well as audit the RSAF's corneal refractive surgery (CRS) program. This is a retrospective case series of 149 eyes of 76 consecutive patients that underwent PRK as part of the RSAF CRS program over the 5-yr period from 1 January 2006 to 31 December 2010. The median patient age was 21 yr (range, 18-26 yr) and the mean preoperative spherical equivalent (SE) refraction was -3.39 - 1.19 D. Of the patients, 96.1% were men and all were of Asian origin. At the 12-mo follow-up, 98.5% of eyes had an uncorrected distance visual acuity (UDVA) of < or = 0.00 LogMAR, 100.0% of eyes had an SE refraction of within + 0.50 D of intended correction, and 2.300% of eyes had a loss of corrected distance visual acuity (CDVA) of 0.20 LogMAR. The cumulative incidence of retreatments was 6.7% and cumulative incidence of grade II or worse corneal haze requiring retreatment was 6.0%. Refractive stability was achieved at 3 mo postsurgery. The results of this study suggest that PRK performed within the context of a stringent and structured CRS program on young Asian eyes with low-moderate myopia is both efficacious and safe, with refractive stability achieved by 3 mo.

Laser-assisted subepithelial keratectomy (LASEK) versus laser-assisted in-situ keratomileusis (LASIK) for correcting myopia

PubMed Central

Kuryan, Jocelyn; Cheema, Anjum; Chuck, Roy S

2017-01-01

Background Near-sightedness, or myopia, is a condition in which light rays entering the eye along the visual axis focus in front of the retina, resulting in blurred vision. Myopia can be treated with spectacles, contact lenses, or refractive surgery. Options for refractive surgery include laser-assisted subepithelial keratectomy (LASEK) and laser-assisted in-situ keratomileusis (LASIK). Both procedures utilize a laser to shape the corneal tissue (front of the eye) to correct refractive error, and both create flaps before laser treatment of corneal stromal tissue. Whereas the flap in LASEK is more superficial and epithelial, in LASIK it is thicker and also includes some anterior stromal tissue. LASEK is considered a surface ablation procedure, much like its predecessor, photorefractive keratectomy (PRK). LASEK was developed as an alternative to PRK to address the issue of pain associated with epithelial debridement used for PRK. Assessing the relative benefits and risks/side effects of LASEK and LASIK warrants a systematic review. Objectives To assess the effects of LASEK versus LASIK for correcting myopia. Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Eyes and Vision Trials Register (2016, Issue 10); MEDLINE Ovid (1946 to 24 October 2016); Embase.com (1947 to 24 October 2016); PubMed (1948 to 24 October 2016); LILACS (Latin American and Caribbean Health Sciences Literature Database; 1982 to 24 October 2016); the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), last searched 20 June 2014; ClinicalTrials.gov (www.clinicaltrials.gov); searched 24 October 2016; and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en); searched 24 October 2016. We did not use any date or language restrictions in the electronic searches for trials. Selection criteria We considered only randomized controlled trials (RCTs) for the purposes of this review. Eligible RCTs were those in which myopic participants were assigned randomly to receive either LASEK or LASIK in one or both eyes. We also included paired-eye studies in which investigators randomly selected which of the participant’s eyes would receive LASEK or LASIK and assigned the other eye to the other procedure. Participants were men or women between the ages of 18 and 60 years with myopia up to 12 diopters (D) and/or myopic astigmatism of severity up to 3 D, who did not have a history of prior refractive surgery. Data collection and analysis Two review authors independently screened all reports and assessed the risk of bias in trials included in this review. We extracted data and summarized findings using risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes. In the absence of clinical and methodological heterogeneity across trials, we used a random-effects model to calculate summary effect estimates. We used a fixed-effect model when including fewer than three trials in a meta-analysis. When clinical, methodological, or statistical heterogeneity was observed across trials, we reported our findings in a narrative synthesis. Main results We identified four eligible trials with 538 eyes of 392 participants for the review, but only three trials (154 participants) provided outcome data for analysis. We found no ongoing trials. Two of four trials were from China, one trial was from Turkey, and the location of one trial was not reported. The risk of bias for most domains was unclear due to poor reporting of trial methods; no trial had a protocol or trial registry record. Three trials enrolled participants with mild to moderate myopia (less than −6.50 D); one trial included only participants with severe myopia (more than −6.00 D). The evidence showed uncertainty in whether there is a difference between LASEK and LASIK in uncorrected visual acuity (UCVA) at 12 months, the primary outcome in our review. The RR and 95% confidence interval (CI) at 12 months after surgery was 0.96 (95% CI 0.82 to 1.13) for UCVA of 20/20 or better and 0.90 (95% CI 0.67 to 1.21) for UCVA of 20/40 or better based on data from one trial with 57 eyes (very low-certainty evidence). People receiving LASEK were less likely to achieve a refractive error within 0.5 diopters of the target at 12 months follow-up (RR 0.69, 95% CI 0.48 to 0.99; 57 eyes; very low-certainty evidence). One trial reported mild corneal haze at six months in one eye in the LASEK group and none in the LASIK group (RR 2.11, 95% CI 0.57 to 7.82; 76 eyes; very low-certainty evidence). None of the included trials reported postoperative pain score or loss of visual acuity, spherical equivalent of the refractive error, or quality of life at 12 months. Refractive regression, an adverse event, was reported only in the LASEK group (8 of 37 eyes) compared with none of 39 eyes in the LASIK group in one trial (low-certainty evidence). Other adverse events, such as corneal flap striae and refractive over-correction, were reported only in the LASIK group (5 of 39 eyes) compared with none of 37 eyes in the LASEK group in one trial (low-certainty evidence). Authors’ conclusions Overall, from the available RCTs, there is uncertainty in how LASEK compares with LASIK in achieving better refractive and visual results in mildly to moderately myopic participants. Large, well-designed RCTs would be required to estimate the magnitude of any difference in efficacy or adverse effects between LASEK and LASIK for treating myopia or myopic astigmatism. PMID:28197998

Racial Variations in the Prevalence of Refractive Errors in the United States: The Multi-Ethnic Study of Atherosclerosis

PubMed Central

PAN, CHEN-WEI; KLEIN, BARBARA E.K.; COTCH, MARY FRANCES; SHRAGER, SANDI; KLEIN, RONALD; FOLSOM, AARON; KRONMAL, RICHARD; SHEA, STEVEN J.; BURKE, GREGORY L.; SAW, SEANG-MEI; WONG, TIEN Y.

2013-01-01

PURPOSE To describe racial variations in the prevalence of refractive errors among adult white, Chinese, Hispanic, and black subjects in the United States. DESIGN Cross-sectional data from a prospective cohort study—the Multi-Ethnic Study of Atherosclerosis (MESA). METHODS A total of 6000 adults aged 45 to 84 years living in the United States participated in the study. Refractive error was assessed, without cycloplegia, in both eyes of all participants using an autorefractor. After excluding eyes with cataract, cataract surgery, or previous refractive surgery, the eye with the larger absolute spherical equivalent (SE) value for each participant was used to classify refractive error. Any myopia was defined as SE of −1.0 diopters (D) or less; high myopia was defined as SE of −5.0 D or less; any hyperopia was defined as SE of +1.0 D or more; clinically significant hyperopia was defined as SE of +3.0 D or more. Astigmatism was defined as a cylinder value of +1.0 D or more. RESULTS After excluding 508 participants with cataracts in both eyes, 838 participants with cataract surgery, 90 participants with laser refractive surgery, and 134 participants who refused to remove their contact lenses for the refraction measurement, 4430 adults with refractive error assessment in at least 1 eye contributed to the analysis. The prevalence of myopia among MESA participants was 25.1%, with lowest rates in Hispanic participants (14.2%), followed by black (21.5%) and white participants (31.0%), and highest rates in Chinese participants (37.2%). The overall rates of high myopia and astigmatism were 4.6% and 45.0%, respectively, with Chinese subjects also having the highest rates of high myopia (11.8%) and astigmatism (53.4%). The overall prevalence of any hyperopia was 38.2% and clinically significant hyperopia was 6.1%, with Hispanic participants having the highest rates of hyperopia (50.2%) and clinically significant hyperopia (8.8%). In multivariate analyses adjusting for age, sex, race, and study site, higher education level, being employed, and being taller were associated with a higher prevalence of myopia. In contrast, lower educational level and being shorter were associated with a higher prevalence of hyperopia. CONCLUSIONS Myopia and astigmatism were most prevalent in the Chinese population, with Chinese subjects having 3 times the prevalence of myopia as Hispanic subjects. Hyperopia was most common in Hispanic subjects. These findings provide further insights into variations in refractive errors among different racial groups and have important implications for the eye care services in the United States. PMID:23453694

Racial variations in the prevalence of refractive errors in the United States: the multi-ethnic study of atherosclerosis.

PubMed

Pan, Chen-Wei; Klein, Barbara E K; Cotch, Mary Frances; Shrager, Sandi; Klein, Ronald; Folsom, Aaron; Kronmal, Richard; Shea, Steven J; Burke, Gregory L; Saw, Seang-Mei; Wong, Tien Y

2013-06-01

To describe racial variations in the prevalence of refractive errors among adult white, Chinese, Hispanic, and black subjects in the United States. Cross-sectional data from a prospective cohort study-the Multi-Ethnic Study of Atherosclerosis (MESA). A total of 6000 adults aged 45 to 84 years living in the United States participated in the study. Refractive error was assessed, without cycloplegia, in both eyes of all participants using an autorefractor. After excluding eyes with cataract, cataract surgery, or previous refractive surgery, the eye with the larger absolute spherical equivalent (SE) value for each participant was used to classify refractive error. Any myopia was defined as SE of -1.0 diopters (D) or less; high myopia was defined as SE of -5.0 D or less; any hyperopia was defined as SE of +1.0 D or more; clinically significant hyperopia was defined as SE of +3.0 D or more. Astigmatism was defined as a cylinder value of +1.0 D or more. After excluding 508 participants with cataracts in both eyes, 838 participants with cataract surgery, 90 participants with laser refractive surgery, and 134 participants who refused to remove their contact lenses for the refraction measurement, 4430 adults with refractive error assessment in at least 1 eye contributed to the analysis. The prevalence of myopia among MESA participants was 25.1%, with lowest rates in Hispanic participants (14.2%), followed by black (21.5%) and white participants (31.0%), and highest rates in Chinese participants (37.2%). The overall rates of high myopia and astigmatism were 4.6% and 45.0%, respectively, with Chinese subjects also having the highest rates of high myopia (11.8%) and astigmatism (53.4%). The overall prevalence of any hyperopia was 38.2% and clinically significant hyperopia was 6.1%, with Hispanic participants having the highest rates of hyperopia (50.2%) and clinically significant hyperopia (8.8%). In multivariate analyses adjusting for age, sex, race, and study site, higher education level, being employed, and being taller were associated with a higher prevalence of myopia. In contrast, lower educational level and being shorter were associated with a higher prevalence of hyperopia. Myopia and astigmatism were most prevalent in the Chinese population, with Chinese subjects having 3 times the prevalence of myopia as Hispanic subjects. Hyperopia was most common in Hispanic subjects. These findings provide further insights into variations in refractive errors among different racial groups and have important implications for the eye care services in the United States. Copyright © 2013 Elsevier Inc. All rights reserved.

"Alcohol Myopia," Expectations, Social Interests, and Sorority Pledge Status.

ERIC Educational Resources Information Center

Elias, Jeffrey W.; And Others

1996-01-01

Examines "alcohol myopia" (an increased use of alcohol in the face of increased negative consequences of use) in freshman college women with or without sorority pledge status. Increased alcohol use and alcohol myopia were present in the sorority pledge group. Both groups showed anomalous myopic behavior as alcohol use increased. (RJM)

Optical treatment strategies to slow myopia progression: Effects of the visual extent of the optical treatment zone

PubMed Central

Smith, Earl L.

2013-01-01

In order to develop effective optical treatment strategies for myopia, it is important to understand how visual experience influences refractive development. Beginning with the discovery of the phenomenon of form deprivation myopia, research involving many animal species has demonstrated that refractive development is regulated by visual feedback. In particular, animal studies have shown that optically imposed myopic defocus slows axial elongation, that the effects of vision are dominated by local retinal mechanisms, and that peripheral vision can dominate central refractive development. In this review, the results obtained from clinical trials of traditional optical treatment strategies employed in efforts to slow myopia progression in children are interpreted in light of the results from animal studies and are compared to the emerging results from preliminary clinical studies of optical treatment strategies that manipulate the effective focus of the peripheral retina. Overall, the results suggest that imposed myopic defocus can slow myopia progression in children and that the effectiveness of an optical treatment strategy in reducing myopia progression is influenced by the extent of the visual field that is manipulated. PMID:23290590

Education, reading, and familial tendency as risk factors for myopia in Hong Kong fishermen.

PubMed Central

Wong, L; Coggon, D; Cruddas, M; Hwang, C H

1993-01-01

STUDY OBJECTIVE--The aim was to assess the influence of childhood reading on the development of myopia after allowance for familial differences in susceptibility. DESIGN--The study was a cross sectional survey. SETTING--Four fishing harbours in Hong Kong in 1989. SUBJECTS--Participants were 408 men and women aged 15-39 years old from 159 families. MAIN RESULTS--Histories of school attendance and reading habits in childhood were obtained at interview. Myopia was assessed by retinoscopy. Associations between myopia (defined as a refractive error of at least -1.0D in one or both eyes) and indices of reading in childhood were explored. Myopia was more common in subjects who had attended school (odds ratio = 1.7, 95% CI 1.0-3.0), with the highest risks in those who had started school at the earliest ages and who had spent the most time reading and writing while at primary school. Allowance for familial tendency to myopia produced no diminution in the risks associated with reading. CONCLUSIONS--These data support the hypothesis that reading in childhood is a cause of short sight. PMID:8436895

Preliminary results of tracked photorefractive keratectomy (T-PRK) for mild to moderate myopia with the autonomous technologies excimer laser at Cedars-Sinai Medical Center

NASA Astrophysics Data System (ADS)

Maguen, Ezra I.; Salz, James J.; Nesburn, Anthony B.

1997-05-01

Preliminary results of the correction of myopia up to -7.00 D by tracked photorefractive keratectomy (T-PRK) with a scanning and tracking excimer laser by Autonomous Technologies are discussed. 41 eyes participated (20 males). 28 eyes were evaluated one month postop. At epithelization day mean uncorrected vision was 20/45.3. At one month postop, 92.8 of eyes were 20/40 and 46.4% were 20/20. No eye was worse than 20/50. 75% of eyes were within +/- 0.5 D of emmetropia and 82% were within +/- 1.00 D of emmetropia. Eyes corrected for monovision were included. One eye lost 3 lines of best corrected vision, and had more than 1.00 D induced astigmatism due to a central corneal ulcer. Additional complications included symptomatic recurrent corneal erosions which were controlled with topical hypertonic saline. T-PRK appears to allow effective correction of low to moderate myopia. Further study will establish safety and efficacy of the procedure.

Environmental factors explain socioeconomic prevalence differences in myopia in 6-year-old children.

PubMed

Tideman, J Willem L; Polling, Jan Roelof; Hofman, Albert; Jaddoe, Vincent Wv; Mackenbach, Johan P; Klaver, Caroline Cw

2018-02-01

High myopia (≤-6 D) usually has its onset before 10 years of age and can lead to blinding complications later in life. We examined whether differences in myopia prevalences in socioeconomic risk groups could be explained by differences in lifestyle factors. A total of 5711 six-year-old children participating in the prospective population-based birth cohort study Generation R underwent a stepwise ophthalmic examination, which included visual acuity and objective cycloplegic refraction to identify children with myopia (≤-0.5D). Daily activities, ethnicity, factors representing family socioeconomic status and housing were ascertained by questionnaire. Risk assessments of myopia and mediation analyses were performed using logistic regression; attenuation of risks was calculated by bootstrapping. Prevalence of myopia was 2.4% (n=137). Myopic children spent more time indoors and less outdoors than non-myopic children (p<0.01), had lower vitamin D (p=0.01), had a higher body mass index and participated less in sports (p=0.03). Children of non-European descent (OR 2.60; 95% CI 1.84 to 3.68), low maternal education (OR 2.27; 95% CI 1.57 to 3.28) and low family income (OR 2.62; 95% CI 1.8 to 3.74) were more often myopic. Lifestyle factors explained the majority of the increased risk for ethnicity (82%; 95% CI 55 to 120), maternal education (69%; 95% CI 45 to 109) and family socioeconomic status (71%; 95% CI 46 to 104). This study found environmental factors to be strong risk factors for myopia already at the age of 6 years. The myopia prevalence differences in socioeconomic groups were greatly determined by differences in distribution of these environmental risk factors, highlighting the importance of lifestyle adjustments in young children developing myopia. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Refractive errors in a Brazilian population: age and sex distribution.

PubMed

Ferraz, Fabio H; Corrente, José E; Opromolla, Paula; Padovani, Carlos Roberto; Schellini, Silvana A

2015-01-01

To determine the prevalence of refractive errors and their distribution according to age and sex in a Brazilian population. This population-based cross-sectional study involved 7654 Brazilian inhabitants of nine municipalities of Sao Paulo State, Brazil, between March 2004 and July 2005. Participants aged >1 year were selected using a random, stratified, household cluster sampling technique, excluding individuals with previous refractive or cataract surgery. Myopia was defined as spherical equivalent (SE) ≤-0.5D, high myopia as SE ≤-3.0D, hyperopia as SE ≥+0.5D, high hyperopia as SE ≥+3D, astigmatism as ≤-0.5DC and anisometropia as ≥1.0D difference between eyes. Age, sex, complaints and a comprehensive eye examination including cycloplegic refraction test were collected and analysed using descriptive analysis, univariate and multivariate methods. The prevalence of astigmatism was 59.7%, hyperopia 33.8% and myopia was 25.3%. Astigmatism had a progressive increase with age. With-the-rule (WTR) axes of astigmatism were more frequently observed in the young participants and the against-the-rule (ATR) axes were more frequent in the older subjects. The onset of myopia occurred more frequently between the 2nd and 3rd decades of life. Anisometropia showed a prevalence of 13.2% (95% CI 12.4-13.9; p < 0.001). There was an association between age and all types of refractive error and hyperopia was also associated with sex. Hyperopia was associated with WTR axes (odds ratio 0.73; 95% CI: 0.6-0.8; p < 0.001) and myopia with ATR axes (odds ratio 0.66; 95% CI: 0.6-0.8; p < 0.001). Astigmatism was the most prevalent refractive error in a Brazilian population. There was a strong relationship between age and all refractive errors and between hyperopia and sex. WTR astigmatism was more frequently associated with hyperopia and ATR astigmatism with myopia. The vast majority of participants had low-grade refractive error, which favours planning aimed at correction of refractive error in the population. © 2014 The Authors Ophthalmic & Physiological Optics © 2014 The College of Optometrists.

Study of Pattern of Change in Handwriting Class Characters with Different Grades of Myopia.

PubMed

Hedge, Shruti Prabhat; Dayanidhi, Vijay Kautilya; Sriram

2015-12-01

Handwriting is a visuo-motor skill highly dependent on visual skills. Any defect in the visual inputs could affect a change in the handwriting. Understanding the variation in handwriting characters caused by visual acuity change can help in identifying learning disabilities in children and also assess the disability in elderly. In our study we try to analyse and catalogue these changes in the handwriting of a person. The study was conducted among 100 subjects having normal visual acuity. They were asked to perform a set of writing tasks, after which the same tasks were repeated after inducing different grades of myopia. Changes in the handwriting class characters were analysed and compared in all grades of myopia. In the study it was found that the letter size, pastiosity, word omissions, inability to stay on line all increase with changes in visual acuity. However these finding are not proportional to the grade of myopia. From the findings of the study it can be concluded that myopia significantly influences the handwriting and any change in visual acuity would induce corresponding changes in handwriting. There is increase in letter size, pastiosity where as the ability to stay on line and space between the lines decrease in different grades of myopia. The changes are not linear and cannot be used to predict the grade of myopia but can be used as parameters suggestive of refractive error.

[Outdoor activity and myopia among 681 primary students in urban and rural regions of Beijing].

PubMed

Guo, Yin; Liu, Lijuan; Xu, Liang; Lü, Yanyun; Tang, Ping; Feng, Yi

2014-01-21

To explore the association between outdoor activity and myopia among 681 primary students from Beijing. School-based, cross-sectional investigation. Eye examination includes the visual acuity test, auto-refractor, slit lamp, ocular biometry and non-mydriatic fundus camera. Questionnaire includes regular items, near work, outdoor activity and social-economic status. The mean time spent outdoors was 1.6 ± 0.8 hours daily. Time spent on outdoor sports and outdoor leisure were 0.7 ± 0.1 hours daily, 1.0 ± 0.8 hours daily, respectively. Mean time of outdoor activity in urban was 1.1 ± 0.4 hours daily, compared with 2.2 ± 0.8 hours daily in rural (P = 0.000). In grade-1, total time spent outdoors is significantly different between myopia and non-myopia (1.4 ± 0.6 vs 1.8 ± 0.8 hours daily, P = 0.000), similar to outdoor leisure (0.8 ± 0.6 vs 1.1 ± 0.9 hours daily, P = 0.000). The same trend was also found in grade-4. The mean time spent outdoors was 1.6 ± 0.8 hours daily. Myopia spent a lower outdoor activity compared with non-myopia. More outdoor activity, e.g., in schools, may potentially be helpful to reduce the high prevalence of myopia in the young generation.

Environmental Myopia: The Case for Bifocals

ERIC Educational Resources Information Center

North, Chris; Hutson, Garrett

2011-01-01

Domestic and international tourists have major impacts on Aotearoa/New Zealand, both positive and negative. In 2010, tourism was the biggest export earner and continues to grow. Environmental consequences of tourism are also growing. Ways of addressing the environmental impacts caused by a mobile society continue to be debated from a variety of…

Endothelial cell density after photorefractive keratectomy for moderate myopia using a 213 nm solid-state laser system.

PubMed

Tsiklis, Nikolaos S; Kymionis, George D; Pallikaris, Aristofanis I; Diakonis, Vasilios F; Ginis, Harilaos S; Kounis, George A; Panagopoulou, Sophia I; Pallikaris, Ioannis G

2007-11-01

To evaluate whether photorefractive keratectomy (PRK) for moderate myopia using a solid-state laser with a wavelength of 213 nm alters the corneal endothelial cell density. University refractive surgery center. The corneal endothelium was analyzed preoperatively and 1, 6, and 12 months postoperatively using corneal confocal microscopy (modified HRT II with a Rostock Cornea Module, Heidelberg Engineering) in 60 eyes (30 patients). Patients were randomized to have myopic PRK using a 213 nm wavelength solid-state laser (study group) or a conventional 193 nm wavelength excimer laser (control group). Three endothelial images were acquired in each of 30 preoperative normal eyes to evaluate the repeatability of endothelial cell density measurements. Repeated-measures analysis of variance was used to compare the variations in endothelial cell density between the 2 lasers and the changes in endothelial cell density over time. There were no statistically significant differences in sex, age, corneal pachymetry, attempted correction, preoperative endothelial cell density, or postoperative refractive outcomes (uncorrected visual acuity, best spectacle-corrected visual acuity, and spherical equivalent refraction) between the 2 groups (P>.05). The coefficient of repeatability of endothelial cell density was 131 cells/mm(2). The measured endothelial cell count per 1.0 mm(2) did not significantly change up to 1 year postoperatively in either group (both P>.05). No statistically significant difference was found between the 2 groups in any postoperative interval (P>.05). Photorefractive keratectomy for moderate myopia using a 213 nm wavelength solid-state laser or a conventional 193 nm wavelength excimer laser did not significantly affect corneal endothelial density during the 1-year postoperative period.

Safety and efficacy of wavefront-guided myopic laser in situ keratomileusis using a new wavefront sensor technology: first 100 cases.

PubMed

Smadja, David; Santhiago, Marcony R; Tellouck, Joy; De Castro, Tania; Lecomte, Fanny; Mello, Glauco R; Touboul, David

2015-08-01

To evaluate the safety and efficacy of wavefront-guided laser in situ keratomileusis (LASIK) for the correction of low to high myopia and myopic astigmatism using data derived from a new-generation Hartmann-Shack aberrometer. Refractive Surgery Unit, Bordeaux Hospital University, France. Retrospective case series. This retrospective study analyzed the initial group of eyes treated with wavefront-guided LASIK for myopia and myopic astigmatism using the Visx S4IR excimer laser and wavefront data derived from a new Hartmann-Shack aberrometer (iDesign Advanced Wavescan aberrometer). Refractive (refraction and refractive accuracy) and visual outcomes (uncorrected [UDVA] and corrected [CDVA] distance visual acuities) were recorded 3 months postoperatively. The study included 100 eyes of 50 consecutively treated patients. The mean decimal UDVA improved from 0.1 ± 0.1 (SD) preoperatively to 1.1 ± 0.15 postoperatively (P < .01). A monocular UDVA of 20/16, 20/20, and 20/25 were achieved in 76.6%, 94.4%, and 96.6% of eyes, respectively. The postoperative manifest spherical equivalent was within ±0.5 diopter in all eyes. No eye lost 2 or more lines of CDVA, and 29.2% of the eyes gained 1 or more lines of CDVA. Wavefront-guided LASIK performed using data derived from the new Hartmann-Shack aberrometer was safe, effective, and predictable for treating myopia and myopic astigmatism. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Birth order and myopia.

PubMed

Guggenheim, Jeremy A; McMahon, George; Northstone, Kate; Mandel, Yossi; Kaiserman, Igor; Stone, Richard A; Lin, Xiaoyu; Saw, Seang Mei; Forward, Hannah; Mackey, David A; Yazar, Seyhan; Young, Terri L; Williams, Cathy

2013-12-01

An association between birth order and reduced unaided vision (a surrogate for myopia) has been observed previously. We examined the association between birth order and myopia directly in four subject groups. Subject groups were participants in (1) the Avon Longitudinal Study of Parents and Children (ALSPAC; UK; age 15 years; N = 4401), (2) the Singapore Cohort Study of Risk Factors for Myopia (SCORM; Singapore; age 13 years; N = 1959), (3) the Raine Eye Health Study (REHS; Australia; age 20 years; N = 1344), and (4) Israeli Defense Force Pre-recruitment Candidates (IDFC; Israel; age 16-22 years; N = 888,277). The main outcome was odds ratios (OR) for myopia in first-born versus non-first-born individuals after adjusting for potential risk factors. The prevalence of myopia was numerically higher in first-born versus non-first-born individuals in all study groups, but the strength of evidence varied widely. Adjusted ORs (95% confidence intervals, CIs) were: ALSPAC, 1.31 (1.05-1.64); SCORM, 1.25 (0.89-1.77); REHS, 1.18 (0.90-1.55); and IDFC, 1.04 (1.03-1.06). In the large IDFC sample, the effect size was greater (a) for the first-born versus fourth- or higher-born comparison than for the first-born versus second/third-born comparison (p < 0.001) and (b) with increasing myopia severity (p < 0.001). Across all studies, the increased risk of myopia in first-born individuals was low (OR < 1.3). Indeed, only the studies with >4000 participants provided strong statistical support for the association. The available evidence suggested the relationship was independent of established risk factors such as time outdoors/reading, and thus may arise through a different causal mechanism.

Refractive status of indigenous people in the northwestern Amazon region of Brazil.

PubMed

Thorn, Frank; Cruz, Antonio A V; Machado, André J; Carvalho, Ricardo A C

2005-04-01

The purpose of this study was to investigate the refractive status of the illiterate indigenous people of the upper Rio Negro region of the Amazon rain forest in northwestern Brazil. From an overall sample of 486 people, 259 indigenous people and 78 Brazilians between 12 and 59 years of age with no compromising optical opacities were refracted with cycloplegic retinoscopy. Subjects were categorized as indigenous if they had at least three generations of indigenous ancestry with no folklore suggesting other ancestors. Myopia was rare among the indigenous population. Only 2.7% of eyes showed myopia of -1.00 D or more and 1.6% (four people) had bilateral myopia of -1.00 D or more. Half of this small group were the only educated indigenous people examined. The prevalence of astigmatism and anisometropia equal to or >1.00 D was 15.5% and 8.2%, respectively. Most of the astigmatism in the indigenous people had an against-the-rule axis. Age was not associated with the refractive errors of the indigenous people. Brazilians from the small city in which the study was performed had higher rates of myopia (6.4% of eyes and 5.1% of subjects bilaterally). Older preeducation adults also had a very low prevalence of myopia (3.2% of eyes and 2.0% of subjects), whereas the younger, slightly educated Brazilians had a higher prevalence of myopia (11.3% of eyes and 9.7% of subjects). The low prevalence of myopia in the illiterate indigenous people is consistent with other studies and suggests that myopia is related to literacy. The generational change among the local mixed race Brazilians further supports this conclusion. The relatively high rates of astigmatism and anisometropia in the indigenous people were unusual for a predominantly emmetropic sample.

Time Outdoors and Physical Activity as Predictors of Incident Myopia in Childhood: A Prospective Cohort Study

PubMed Central

Guggenheim, Jeremy A.; Northstone, Kate; McMahon, George; Ness, Andy R.; Deere, Kevin; Mattocks, Calum; Pourcain, Beate St; Williams, Cathy

2012-01-01

Purpose. Time spent in “sports/outdoor activity” has shown a negative association with incident myopia during childhood. We investigated the association of incident myopia with time spent outdoors and physical activity separately. Methods. Participants in the Avon Longitudinal Study of Parents and Children (ALSPAC) were assessed by noncycloplegic autorefraction at ages 7, 10, 11, 12, and 15 years, and classified as myopic (≤−1 diopters) or as emmetropic/hyperopic (≥−0.25 diopters) at each visit (N = 4,837–7,747). Physical activity at age 11 years was measured objectively using an accelerometer, worn for 1 week. Time spent outdoors was assessed via a parental questionnaire administered when children were aged 8–9 years. Variables associated with incident myopia were examined using Cox regression. Results. In analyses using all available data, both time spent outdoors and physical activity were associated with incident myopia, with time outdoors having the larger effect. The results were similar for analyses restricted to children classified as either nonmyopic or emmetropic/hyperopic at age 11 years. Thus, for children nonmyopic at age 11, the hazard ratio (95% confidence interval, CI) for incident myopia was 0.66 (0.47–0.93) for a high versus low amount of time spent outdoors, and 0.87 (0.76–0.99) per unit standard deviation above average increase in moderate/vigorous physical activity. Conclusion. Time spent outdoors was predictive of incident myopia independently of physical activity level. The greater association observed for time outdoors suggests that the previously reported link between “sports/outdoor activity” and incident myopia is due mainly to its capture of information relating to time outdoors rather than physical activity. PMID:22491403

Birth order and myopia

PubMed Central

Guggenheim, Jeremy A.; McMahon, George; Northstone, Kate; Mandel, Yossi; Kaiserman, Igor; Stone, Richard A.; Lin, Xiaoyu; Saw, Seang Mei; Forward, Hannah; Mackey, David A.; Yazar, Seyhan; Young, Terri L.; Williams, Cathy

2013-01-01

Purpose An association between birth order and reduced unaided vision (a surrogate for myopia) has been observed previously. We examined the association between birth order and myopia directly in 4 subject groups. Methods Subject groups were participants in 1) the Avon Longitudinal Study of Parents and Children (ALSPAC; UK; age 15 years; N=4,401), 2) the Singapore Cohort Study of Risk Factors for Myopia (SCORM; Singapore; age 13 years; N=1,959), 3) the Raine Eye Health Study (REHS; Australia; age 20 years; N=1,344), and 4) Israeli Defense Force recruitment candidates (IDFC; Israel; age 16-22 years; N=888,277). Main outcome: Odds ratio (OR) for myopia in first born versus non-first born individuals after adjusting for potential risk factors. Results The prevalence of myopia was numerically higher in first-born versus non-first-born individuals in all study groups, but the strength of evidence varied widely. The adjusted ORs (95% CI) were: ALSPAC, 1.31 (1.05-1.64); SCORM, 1.25 (0.89-1.77); REHS, 1.18 (0.90-1.55); IDFC, 1.04 (1.03-1.06). In the large IDFC sample, the effect size was greater (a) for the first born versus fourth or higher born comparison than for the first born versus second/third born comparison (P<0.001) and (b) with increasing myopia severity (P<0.001). Conclusions Across all studies, the increased risk of myopia in first born individuals was low (OR <1.3). Indeed, only the studies with >4000 participants provided strong statistical support for the association. The available evidence suggested the relationship was independent of established risk factors such as time outdoors/reading, and thus may arise through a different causal mechanism. PMID:24168726

High prevalence of refractive errors in a rural population: 'Nooravaran Salamat' Mobile Eye Clinic experience.

PubMed

Hashemi, Hassan; Rezvan, Farhad; Ostadimoghaddam, Hadi; Abdollahi, Majid; Hashemi, Maryam; Khabazkhoob, Mehdi

2013-01-01

The prevalence of myopia and hyperopia and determinants were determined in a rural population of Iran. Population-based cross-sectional study. Using random cluster sampling, 13 of the 83 villages of Khaf County in the north east of Iran were selected. Data from 2001 people over the age of 15 years were analysed. Visual acuity measurement, non-cycloplegic refraction and eye examinations were done at the Mobile Eye Clinic. The prevalence of myopia and hyperopia based on spherical equivalent worse than -0.5 dioptre and +0.5 dioptre, respectively. The prevalence of myopia, hyperopia and anisometropia in the total study sample was 28% (95% confidence interval: 25.9-30.2), 19.2% (95% confidence interval: 17.3-21.1), and 11.5% (95% confidence interval: 10.0-13.1), respectively. In the over 40 population, the prevalence of myopia and hyperopia was 32.5% (95% confidence interval: 28.9-36.1) and 27.9% (95% confidence interval: 24.5-31.3), respectively. In the multiple regression model for this group, myopia strongly correlated with cataract (odds ratio = 1.98 and 95% confidence interval: 1.33-2.93), and hyperopia only correlated with age (P < 0.001). The prevalence of high myopia and high hyperopia was 1.5% and 4.6%. In the multiple regression model, anisometropia significantly correlated with age (odds ratio = 1.04) and cataract (odds ratio = 5.2) (P < 0.001). The prevalence of myopia and anisometropia was higher than that in previous studies in urban population of Iran, especially in the elderly. Cataract was the only variable that correlated with myopia and anisometropia. © 2013 The Authors. Clinical and Experimental Ophthalmology © 2013 Royal Australian and New Zealand College of Ophthalmologists.

Prevalence and risk factors for refractive errors in Indians: the Singapore Indian Eye Study (SINDI).

PubMed

Pan, Chen-Wei; Wong, Tien-Yin; Lavanya, Raghavan; Wu, Ren-Yi; Zheng, Ying-Feng; Lin, Xiao-Yu; Mitchell, Paul; Aung, Tin; Saw, Seang-Mei

2011-05-16

To determine the prevalence and risk factors for refractive errors in middle-aged to elderly Singaporeans of Indian ethnicity. A population-based, cross-sectional study of Indians aged over 40 years of age residing in Southwestern Singapore was conducted. An age-stratified (10-year age group) random sampling procedure was performed to select participants. Refraction was determined by autorefraction followed by subjective refraction. Myopia was defined as spherical equivalent (SE) < -0.50 diopters (D), high myopia as SE < -5.00 D, astigmatism as cylinder < -0.50 D, hyperopia as SE > 0.50 D, and anisometropia as SE difference > 1.00 D. Prevalence was adjusted to the 2000 Singapore census. Of the 4497 persons eligible to participate, 3400 (75.6%) were examined. Complete data were available for 2805 adults with right eye refractive error and no prior cataract surgery. The age-adjusted prevalence was 28.0% (95% confidence interval [CI], 25.8-30.2) for myopia and 4.1% (95% CI, 3.3-5.0) for high myopia. There was a U-shaped relationship between myopia and increasing age. The age-adjusted prevalence was 54.9% (95% CI, 52.0-57.9) for astigmatism, 35.9% (95% CI, 33.7-38.3) for hyperopia, and 9.8% (95% CI, 8.6-11.1) for anisometropia. In a multiple logistic regression model, adults who were female, younger, taller, spent more time reading and writing per day, or had astigmatism were more likely to be myopic. Adults who were older or had myopia or diabetes mellitus had higher risk of astigmatism. In Singapore, the prevalence of myopia in Indian adults is similar to those in Malays, but lower than those in Chinese. Risk factors for myopia are similar across the three ethnic groups in Singapore.

Iris colour in relation to myopia among Chinese school-aged children.

PubMed

Pan, Chen-Wei; Qiu, Qin-Xiao; Qian, Deng-Juan; Hu, Dan-Ning; Li, Jun; Saw, Seang-Mei; Zhong, Hua

2018-01-01

Understanding the association of iris colour and myopia may provide further insights into the role of the wavelength of lights in the pathophysiology of myopia. We aim to assess the association of iris colour and myopia in a school-based sample of Chinese students. Two thousand three hundred and forty-six Year 7 students from 10 middle schools (93.5% response rate) aged 13-14 years in Mojiang, a small county located in Southwestern China, participated in the study. We obtained standardised slit lamp photographs and developed a grading system assessing iris colour (higher grade denoting a darker iris). Refractive error was measured after cycloplegia using an autorefractor by optometrists or trained technicians. An IOLMaster (www.zeiss.com) was used to measure ocular biometric parameters including axial length (AL). Of all the study participants, 693 (29.5%) were affected by myopia with the prevalence estimates being higher in girls (36.8%; 95% confidence interval [CI]: 34.0, 39.6) than in boys (22.8%; 95% CI: 20.4, 25.1) (p < 0.001). After adjusting for gender, height, parental history of myopia, time spent on computer, time spent watching TV, time spent outdoors, and time spent reading and writing, participants with a darker iris colour tended to have a higher prevalence of myopia, a more myopic refraction and a longer AL. Dose-response relationships were observed in all regression models (p for trend <0.05). Darker iris colour was associated with more myopic refractive errors and longer ALs among Chinese school-aged children and this association was independent of other known myopia-related risk factors. © 2017 The Authors Ophthalmic & Physiological Optics © 2017 The College of Optometrists.

Refractive Error and the Risk of Age-Related Macular Degeneration in the South Korean Population.

PubMed

Lin, Shuai-Chun; Singh, Kuldev; Chao, Daniel L; Lin, Shan C

2016-01-01

We investigated the association between refractive error and the prevalence of age-related macular degeneration (AMD) in a population-based study. This was a cross-sectional study. Right eyes were included from 14,067 participants aged 40 years and older with gradable fundus photographs and refraction data from the fourth and the fifth Korea National Health and Nutrition Examination Survey 2008 to 2011. Early and late AMD was graded based on the International Age-Related Maculopathy Epidemiological Study Group grading system. Autorefraction data were collected to calculate spherical equivalent refraction in diopters (D) and classified into 4 groups: hyperopia (≥1.0 D), emmetropia (-0.99 to 0.99 D), mild myopia (-1.0 to -2.99 D), and moderate to high myopia (≤-3.0 D). After adjustment for potential confounders, each diopter increase in spherical equivalent was associated with a 16% [odds ratio (OR), 1.16; 95% confidence interval (CI), 1.08-1.25] and 18% (OR, 1.18; 95% CI, 1.10-1.27) increased risk of any (early + late) and early AMD, respectively. Mild and moderate to high myopia were associated with lower odds of any and early AMD compared with hyperopia (any AMD: OR, 0.62; 95% CI, 0.4-0.95 for mild myopia; OR, 0.41; 95% CI, 0.21-0.81 for moderate to high myopia; early AMD: OR, 0.63; 95% CI, 0.4-0.99 for mild myopia; OR, 0.36; 95% CI, 0.16-0.77 for moderate to high myopia group). There was no association between refractive status and the likelihood of late AMD (P = 0.91). Myopia is associated with lower odds of any and early AMD, but not with late AMD in the South Korean population.

An updated view on the role of dopamine in myopia.

PubMed

Feldkaemper, Marita; Schaeffel, Frank

2013-09-01

A large body of data is available to support the hypothesis that dopamine (DA) is one of the retinal neurotransmitters involved in the signaling cascade that controls eye growth by vision. Initially, reduced retinal DA levels were observed in eyes deprived of sharp vision by either diffusers ("deprivation myopia", DM) or negative lenses ("lens induced myopia", LIM). Simulating high retinal DA levels by intravitreal application of a DA agonist can suppress the development of both DM and LIM. Also more recent studies using knock-out mouse models of DA receptors support the idea of an association between decreased DA levels and DM. There seem to be differences in the magnitude of the effects of DA on DM and LIM, with larger changes in DM but the degrees of image degradation by both treatments need to be matched to support this conclusion. Although a number of studies have shown that the inhibitory effects of dopamine agonists on DM and LIM are mediated through stimulation of the D2-receptor, there is also recent evidence that the balance of D2- and D1-receptor activation is important. Inhibition of D2-receptors can also slow the development of spontaneous myopia in albino guinea pigs. Retinal DA content displays a distinct endogenous diurnal, and partially circadian rhythm. In addition, retinal DA is regulated by a number of visual stimuli like retinal illuminance, spatial frequency content of the image, temporal contrast and, in chicks, by the light input from the pineal organ. A close interaction was found between muscarinergic and dopaminergic systems, and between nitric oxide and dopaminergic pathways, and there is evidence for crosstalk between the different pathways, perhaps multiple binding of the ligands to different receptors. It was shown that DA agonists interact with the immediate early signaling molecule ZENK which triggers the first steps in eye growth regulation. However, since long treatment periods were often needed to induce significant changes in retinal dopamine synthesis and release, the role of dopamine in the early steps is unclear. The wide spatial distribution of dopaminergic amacrine cells in the retina and the observation that changes in dopamine levels can be locally induced by local retinal deprivation is in line with the assumption that dopaminergic mechanisms control both central and peripheral eye growth. The protective effect of outdoor activity on myopia development in children seems to be partly mediated by the stimulatory effect of light on retinal dopamine production and release. However, the dose-response function linking light exposure to dopamine and to the suppression of myopia is not known and requires further studies. Copyright © 2013 Elsevier Ltd. All rights reserved.

[Analysis of eyeball development in children between the fourth month and seventh year of life with regard to eyeball length, refraction value and fundus].

PubMed

Borowiec, A

2000-01-01

An ophthalmologic screening of three-month-old infants was conducted between 1990 and 1993 in the province of Szczecin. The screening was aimed at early detection and treatment of vision defects and diseases of the eye. Attention was also focused on the appearance of the eyeballs. Approximately 50% of children had a retina of more or less "reduced density". The fundus appeared much like in the case of near-sightedness, raising the question whether such eye would continue towards myopia or would this just be a morphological trait of immature retina which will disappear with growth and development of the eyeball. The children were selected among those reporting for ophthalmologic screening and were divided into four groups: I--children with retina of "reduced density" and near-sightedness in the family (at least one parent had myopia), 45 children--90 eyes; II--children with retina of reduced density, whose parents did not have myopia, 45 children--90 eyes; III--children without changes in the fundus and with near-sightedness in the family, 30 children--60 eyes; IV--children without changes in the fundus, whose parents did not have myopia, 30 children--60 eyes. An additional group consisted of children without family history of near-sightedness, in whom myopia was -5.0 D sph or more during skiascopy with cycloplegia when the child finished six months of life (10 children--20 eyes). The following was examined in all children after three months of life: pupillary reflexes, fixation, anterior segment of eyeball, eyeball length, fundus, intraocular pressure, and refraction. The examination was repeated when the children finished three years, and six years ten months of life. Skiascopy was performed with prior cycloplegia. Statistics were done using Mann-Whitney test for unpaired and Wilcoxon's test for paired results. The following conclusions were made: 1. Length of the eyeball was not related to the appearance of fundus or family history of myopia (Tab. 1). Growth of the eyeball could be divided into two periods. The first was fast, lasting until the end of the third year of life. The second was slow and by the end of the seventh year, growth was almost complete. In children with inborn near-sightedness, the eyeballs were already longer in the fourth month of life. 2. Average size of refraction after cycloplegia in six-month-old infants does not depend on the appearance of eye fundus or family history of near-sightedness. Between six months and three years of life, a limited increase in refraction took place, whereas between the fourth and seventh year of life a decrease was observed. This decrease was significantly greater in children with a family history of near-sightedness. In children with inborn near-sightedness, there was no increase in refraction and decrease proceeded at a faster pace. In six-month-old infants, reversed astigmatism predominated, but between the seventh month and fourth year of life it declined and between the fourth and seventh year its axis changed (Tab. 3 and 4). 3. "Reduced density" found in three-month-old infants is a morphological trait of the retina and does not predispose to near-sightedness. It occurs more often in children with blue or light gray color of the iris, i.e. with little pigment in the stroma (Tab. 6). In most cases, "reduced density" disappeared before the end of the third year of life (Tab. 5). In children with inborn near-sightedness it was not possible to assess on the grounds of the eye speculum whether the observed reduced density was caused by lack of pigment in the pigmented layer of the eyeball or by near-sightedness, or both.

What Do Animal Studies Tell Us about the Mechanism of Myopia-Protection by Light?

PubMed

Norton, Thomas T

2016-09-01

: Human studies have provided strong evidence that exposure to time outdoors is protective against the onset of myopia. A causal factor may be that the light levels outdoors (30,000-130,000 lux) are much higher than light levels indoors (typically less than 500 lux). Studies using animal models have found that normal animals exposed to low illuminance levels (50 lux) can develop myopia. The myopia and axial elongation, produced in animals by monocular form deprivation, is reduced by light levels in the 15,000 to 25,000 range. Myopia induced with a negative-power lens seems less affected, perhaps because the lens provides a powerful target for the emmetropization mechanism. Animal studies suggest that raising the light levels may have their effect by increasing retinal dopamine activity, probably via the D2 receptor pathway, altering gene expression in the retina and reducing the signals that produce axial elongation.

Prevalence of myopia in an adult population of two different ethnic groups in the Ecuadorian Amazon.

PubMed

Jiménez, José Ramón; Bermúdez, Javier; Rubiño, Manuel; Gómez, Luis; Anera, Rosario González

2004-01-01

To determine the prevalence of myopia in the adult populations of two different ethnic communities in the Ecuadorian Amazon. Refraction with retinoscopy after cycloplegia was performed for 507 Naporuna (an ethnic group indigenous to the jungles of the Ecuadorian Amazon) and for 776 settlers (white-mestizos from the Andes, now living in the Amazon and working for the petroleum industry). Ages ranged from 18 to 45 years. All subjects had little or no formal education. The prevalence of myopia was 4.7% among the Naporuna and 5.5% among the settlers; the prevalence of hyperopia was higher, at 17.8% and 36.0%, respectively. The prevalence of myopia in the two communities studied agrees with the results of other studies showing a low prevalence of myopia among groups with low levels of formal education or groups living a nonurban lifestyle.

Interactions of chromatic and lens-induced defocus during visual control of eye growth in guinea pigs (Cavia porcellus).

PubMed

Jiang, Liqin; Zhang, Sen; Schaeffel, Frank; Xiong, Shibo; Zheng, Yibo; Zhou, Xiangtian; Lu, Fan; Qu, Jia

2014-01-01

It was recently demonstrated that chromaticity could affect eye growth and refractive development in guinea pigs but it remained unclear whether correction with spectacle lenses could balance these effects and how retinal responses change with different spectral compositions of light. Three illumination conditions were tested: blue, red and white light. Animals were raised without or with monocular spectacle lenses from three to seven weeks of age. Luminance electroretinograms (ERGs) were recorded to explore retinal responses with the different spectral compositions. In our special colony of pigmented guinea pigs, characterized by residual hyperopia, spontaneous myopia and poor emmetropization, red light induced early thinning of the choroid and relative myopia, compared to white light. Effects of red light could not be suppressed if positive spectacle lenses were worn. ERGs showed that red light failed to elicit robust retinal responses. Blue light inhibited axial eye growth, even when animals were reared with negative lenses. Intensity-matched blue and white light elicited similar a-waves but different b-waves, suggesting that the wavelength of light affects visual control of eye growth through different processing in the inner retina. We hypothesize that blue light might stimulate preferentially the ON pathway to inhibit myopia induced by negative lenses, at least in guinea pigs. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Femtosecond laser-assisted LASIK versus PRK for high myopia: comparison of 18-month visual acuity and quality.

PubMed

Hashemi, Hassan; Ghaffari, Reza; Miraftab, Mohammad; Asgari, Soheila

2017-08-01

To compare 18-month outcomes between femtosecond laser-assisted LASIK (femto-LASIK) and photorefractive keratectomy with mitomycin-C (PRK-MMC) for myopia of more than 7.0 D in terms of visual acuity and quality. In this comparative nonrandomized clinical trial, 60 eyes from 30 patients (30 eyes in each group) were enrolled. The two procedures were compared in terms of 18-month changes in uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction spherical equivalent, ocular and corneal higher order aberrations (HOAs), and contrast sensitivity (CS). Mean myopia was -8.65 ± 1.51 and -8.04 ± 1.70 D (P = 0.149) and mean ablation depth was 109.37 ± 9.07 and 105.09 ± 12.59 µm (P = 0.138), in the femto-LASIK and PRK-MMC groups, respectively. Baseline parameters were not significantly different between the two groups (all P > 0.05). At 18 months postoperatively, 75 % in the femto-LASIK, versus 57.1 % in the PRK-MMC group, had 20/20 UDVA (P = 0.017). CDVA remained similarly unchanged in both groups (P = 0.616). No case had residual refractive error more than 1.0 D in the femto-LASIK group, while 33.5 % in the other group had more than 1.0 D residual error (P = 0.390). Changes in corneal HOA were not significantly different between the two groups (P = 0.260). Cases in the femto-LASIK group showed more increase in ocular HOA (P = 0.032) and coma (P = 0.083, power = 72 %). CS remained similarly unchanged in all spatial frequencies in both groups (all P > 0.05). Although femto-LASIK induces more HOA compared to PRK-MMC, considering outcomes in terms of 20/20 UDVA, residual refractive error, and CS stability, femto-LASIK provides more favorable results than PRK-MMC in high myopia.

Long-term changes in retinal contrast sensitivity in chicks from frosted occluders and drugs: relations to myopia?

PubMed

Diether, S; Schaeffel, F

1999-07-01

Experiments in animal models have shown that the retinal analyzes the image to identify the position of the plane of focus and fine-tunes the growth of the underlying sclera. It is fundamental to the understanding of the development of refractive errors to know which image features are processed. Since the position of the image plane fluctuates continuously with accommodative status and viewing distance, a meaningful control of refractive development can only occur by an averaging procedure with a long time constant. As a candidate for a retinal signal for enhanced eye growth and myopia we propose the level of contrast adaptation which varies with the average amount of defocus. Using a behavioural paradigm, we have found in chickens (1) that contrast adaptation (CA, here referred to as an increase in contrast sensitivity) occurs at low spatial frequencies (0.2 cyc/deg) already after 1.5 h of wearing frosted goggles which cause deprivation myopia, (2) that CA also occurs with negative lenses (-7.4D) and positive lenses (+6.9D) after 1.5 h, at least if accommodation is paralyzed and, (3) that CA occurs at a retinal level or has, at least, a retinal component. Furthermore, we have studied the effects of atropine and reserpine, which both suppress myopia development, on CA. Quisqualate, which causes retinal degeneration but leaves emmetropization functional, was also tested. We found that both atropine and reserpine increase contrast sensitivity to a level where no further CA could be induced by frosted goggles. Quisqualate increased only the variability of refractive development and of contrast sensitivity. Taken together, CA occurring during extended periods of defocus is a possible candidate for a retinal error signal for myopia development. However, the situation is complicated by the fact that there must be a second image processing mode generating a powerful inhibitory growth signal if the image is in front of the retina, even with poor images (Diether, S., & Schaeffel, F. (1999).

How predictable are the results of excimer laser photorefractive keratectomy? A review.

PubMed

Grosvenor, T

1995-10-01

At the close of 1994, the AOA News reported that at least 14 companies were preparing to market equipment for excimer laser photorefractive keratectomy (PRK). More than a dozen PRK centers had been formed for the purpose of recruiting optometrists to co-manage PRK patients. Because the surgery is a "no-touch" computer-driven procedure whose duration is measured in seconds, the preoperative and postoperative care of PRK patients will assume major importance. Optometrists who will be asked to take part in the management of PRK patients must be able to counsel patients on matters such as the predictability of the procedure in terms of postoperative refractive error and visual acuity, as well as the possibility of unintended consequences such as difficulty in night driving. Information currently available, mainly as a result of studies conducted in other countries, shows that the results of PRK are highly predictable for preoperative myopia up to about -3.00 D and somewhat less predictable for myopia between -3.00 and -6.00 D, whereas for myopia greater than -6.00 D the probability of achieving a full correction decreases rapidly with increasing amounts of myopia. As compared to radial keratotomy (RK) in which the postoperative refractive error drifts relentlessly in the hyperopic direction, PRK brings about an initial hyperopic shift followed by regression leading to increasing myopia. Researchers disagree on the cause of the postoperative hyperopic shift and regression, and on the value of various methods of controlling regression including the use of wider and deeper ablation profiles and the postoperative use of corticosteroids and nonsteroid anti-inflammatory drugs. It is too early to determine whether the myopic creep in PRK will be as persistent as the hyperopic creep in RK, but it is likely that whereas presbyopic post-RK patients may have adequate distance vision but require corrective lenses for reading, presbyopic post-PRK patients may be sufficiently myopic to require lenses for distance vision but not for reading.

Oxidative Stress in Myopia

PubMed Central

Francisco, Bosch-Morell; Salvador, Mérida; Amparo, Navea

2015-01-01

Myopia affected approximately 1.6 billion people worldwide in 2000, and it is expected to increase to 2.5 billion by 2020. Although optical problems can be corrected by optics or surgical procedures, normal myopia and high myopia are still an unsolved medical problem. They frequently predispose people who have them to suffer from other eye pathologies: retinal detachment, glaucoma, macular hemorrhage, cataracts, and so on being one of the main causes of visual deterioration and blindness. Genetic and environmental factors have been associated with myopia. Nevertheless, lack of knowledge in the underlying physiopathological molecular mechanisms has not permitted an adequate diagnosis, prevention, or treatment to be found. Nowadays several pieces of evidence indicate that oxidative stress may help explain the altered regulatory pathways in myopia and the appearance of associated eye diseases. On the one hand, oxidative damage associated with hypoxia myopic can alter the neuromodulation that nitric oxide and dopamine have in eye growth. On the other hand, radical superoxide or peroxynitrite production damage retina, vitreous, lens, and so on contributing to the appearance of retinopathies, retinal detachment, cataracts and so on. The objective of this review is to suggest that oxidative stress is one of the key pieces that can help solve this complex eye problem. PMID:25922643

Night myopia is reduced in binocular vision.

PubMed

Chirre, Emmanuel; Prieto, Pedro M; Schwarz, Christina; Artal, Pablo

2016-06-01

Night myopia, which is a shift in refraction with light level, has been widely studied but still lacks a complete understanding. We used a new infrared open-view binocular Hartmann-Shack wave front sensor to quantify night myopia under monocular and natural binocular viewing conditions. Both eyes' accommodative response, aberrations, pupil diameter, and convergence were simultaneously measured at light levels ranging from photopic to scotopic conditions to total darkness. For monocular vision, reducing the stimulus luminance resulted in a progression of the accommodative state that tends toward the subject's dark focus or tonic accommodation and a change in convergence following the induced accommodative error. Most subjects presented a myopic shift of accommodation that was mitigated in binocular vision. The impact of spherical aberration on the focus shift was relatively small. Our results in monocular conditions support the hypothesis that night myopia has an accommodative origin as the eye progressively changes its accommodation state with decreasing luminance toward its resting state in total darkness. On the other hand, binocularity restrains night myopia, possibly by using fusional convergence as an additional accommodative cue, thus reducing the potential impact of night myopia on vision at low light levels.

[The epidemic status and secular trends of myopia prevalence for Chinese children and adolescents aged 7-18 years from 2005 to 2014].

PubMed

Dong, Y H; Liu, H B; Wang, Z H; Xu, R B; Yang, Z P; Ma, J

2017-04-06

Objective: To investigate the characteristics of geographic distribution and change trend of myopia prevalence for children and adolescents aged 7-18 years old from 2005 to 2014, which provides the basis for the prevention of myopia. Methods: Research material was selected from the data of 2005, 2010, and 2014 Chinese National Survey on Students Constitution and Health, including 31 provinces (with the exception of Hong Kong, Macao, and Taiwan). The complete detection data of binoculus in children and adolescents aged 7-18 years old were selected as our research objects. The research objects of three studies were 233 505, 216 474, and 215 160, respectively. We analyzed the characteristics of geographic distribution and change trend of myopia prevalence for children and adolescents aged 7-18 years old in 31 provinces from 2005 to 2014. Results: The overall myopia detection rates in Chinese children and adolescents aged 7 to 18 years old in 31 provinces were 47.4% (111 707/235 505), 55.6% (120 456/216 474), and 57.2% (122 965/215 160) in 2005, 2010 and 2014, respectively. The growth range in this two phases were 8.0 percentage points, and 1.6 percentage points, respectively, and the difference was statistically significant ( P< 0.05). The detection rate of Myopia was growing quickly from 2005 to 2010 and only three provinces were in the situation of decline state including Tianjin, Hainan, and Ningxia. 90.3 percent (28/31) of provinces were in the situation of growth state and the growth range was 1.3%-22.3%. The growth of myopia was in the situation of slowdown from 2010 to 2014, and 38.7 percent (12/31) of the provinces were in negative growth districts including Hebei, Shanxi, Inner Mongolia, Zhejiang, Fujian, Shandong, Hubei, Guangxi, Guizhou, Tibet, Qianghai, and Xinjiang. The growth range in other provinces was 0.4%-24.7%. Conclusion: The myopia detection rate was at a higher level and growing constantly in China. There was large difference for myopia of children and adolescents among the 31 provinces. However, the overall growth rate of myopia in children and adolescents was in the situation of a relatively low level form 2010 to 2014.

Relationships between macular pigment optical density and lacquer cracks in high myopia.

PubMed

Benoudis, L; Ingrand, P; Jeau, J; Lichtwitz, O; Boissonnot, M; Leveziel, N

2016-09-01

A low concentration of macular carotenoid pigment (lutein and zeaxanthin) is a significant risk factor for macular degeneration. The goal of this paper is to investigate the relationship between macular pigment optical density (MPOD) and lacquer cracks (LC) in high myopia. This is a prospective comparative observational study (NCT02205632) including high myopic patients with or without LC. High myopia was defined as a refractive error greater than 6 diopters of myopia or axial length greater than 26mm. All patients underwent best-corrected visual acuity in logMAR, MPOD measurement, multicolor imaging, SD-OCT, autofluorescence and axial length measurement. MPOD was calculated using heterochromatic flicker photometry. Group 1 was defined as eyes without LC and group 2 as eyes with LC. Forty-five eyes of 32 patients with a mean age of 51.3 years were included in group 1, and 15 eyes of 13 patients aged 54.1 in group 2 (P=0.56). Mean spherical equivalent was -10.11 diopters in group 1 and -15.11 in group 2 (P=0.0004). Mean visual acuity was +0.08 logMAR (0.8 in decimal notation) in group 1 and +0.11 logMAR (0.8 in decimal notation) in group 2 (P=0.061). Axial length was 27.8mm in group 1 and 29.2 in group 2 (P=0.0052). Central macular thickness was lower in group 1 (295μm) than in group 2 (305μm) (P<0.0001), and macular choroidal thickness did not differ between the two groups (P=0.094). Mean MPOD in group 2 was 0.52 and 0.63 in group 1 (P=0.042). Differences in axial length were not related to MPOD measurements (P=0.74). A lower rate of MPOD was observed in cases of LC in high myopia. Further studies are needed to investigate if dietary carotenoids could have a protective effect in reducing the risk of LC. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Study of Pattern of Change in Handwriting Class Characters with Different Grades of Myopia

PubMed Central

Hedge, Shruti Prabhat; Sriram

2015-01-01

Introduction Handwriting is a visuo-motor skill highly dependent on visual skills. Any defect in the visual inputs could affect a change in the handwriting. Understanding the variation in handwriting characters caused by visual acuity change can help in identifying learning disabilities in children and also assess the disability in elderly. In our study we try to analyse and catalogue these changes in the handwriting of a person. Materials and Methods The study was conducted among 100 subjects having normal visual acuity. They were asked to perform a set of writing tasks, after which the same tasks were repeated after inducing different grades of myopia. Changes in the handwriting class characters were analysed and compared in all grades of myopia. Results In the study it was found that the letter size, pastiosity, word omissions, inability to stay on line all increase with changes in visual acuity. However these finding are not proportional to the grade of myopia. Conclusion From the findings of the study it can be concluded that myopia significantly influences the handwriting and any change in visual acuity would induce corresponding changes in handwriting. There is increase in letter size, pastiosity where as the ability to stay on line and space between the lines decrease in different grades of myopia. The changes are not linear and cannot be used to predict the grade of myopia but can be used as parameters suggestive of refractive error. PMID:26816917

Refraction data survey: 2nd generation correlation of myopia.

PubMed

Greene, Peter R; Medina, Antonio

2016-10-01

The objective herein is to provide refraction data, myopia progression rate, prevalence, and 1st and 2nd generation correlations, relevant to whether myopia is random or inherited. First- and second-generation ocular refraction data are assembled from N = 34 families, average of 2.8 children per family. From this group, data are available from N = 165 subjects. Inter-generation regressions are performed on all the data sets, including correlation coefficient r, and myopia prevalence [%]. Prevalence of myopia is [M] = 38.5 %. Prevalence of high myopes with |R| >6 D is [M-] = 20.5 %. Average refraction is  = -1.84 D ± 3.22 (N = 165). For the high myopes, |R| >6 D, prevalence for the parents is [M-] = 25 %, for the 2nd generation [M-] = 16.5 %. Average myopia level for the high myopes, both generations, is  = -7.52 D ± 1.31 D (N = 33). Regression parameters are calculated for all the data sets, yielding correlation coefficients in the range r = 0.48-0.72 for some groups of myopes and high myopes, fathers to daughters, and mothers to sons. Also of interest, some categories show essentially no correlation, -0.20 < r < 0.20, indicating that the refractive errors occur randomly. Time series results show myopia diopter rates = -0.50 D/year.