Longitudinal study of anisometropia in Singaporean school children

PURPOSE: The purpose of this study was to document the incidence rates of anisometropia, year-by-year prevalences, changes in the intereye difference in spherical equivalent (SE), and its association with myopia progression and axial length changes in a cohort of Singaporean school children. METHODS: This is a prospective cohort study of Singaporean school children (n = 1979) aged 7 to 9 years who were examined annually with cycloplegic refraction and ultrasonography over a 3-year period. RESULTS: In the 1908 children without anisometropia at commencement, the 3-year cumulative incidence rate of anisometropia (difference in SE at least 1.0 D) was 144 (7.55%; 95% CI: 6.42-8.85). The mean intereye difference in SE in all children at baseline was 0.29 +/- 0.46 D (SD: 0.46) and increased to 0.44 D (0.59) on the last examination. On the initial examination, 3.6% (95% CI: 2.8-4.4) or 71 children had anisometropia. Of the 59 of 71 children who completed all examinations, only 3 (5.1%) had an increase in the intereye difference in SE by at least 0.5 D, whereas 2 (3.4%) had a decrease of at least 0.5D. The mean intereye difference in SE was stable between visits. The change in intereye difference in SE correlated with the change in intereye axial length (r = 0.43). Compared with the isometropic children, each eye of the anisometropic children had a higher rate of progression of myopia. CONCLUSIONS: The 3-year incidence of anisometropia was 7.55% in these young Singaporean children. Although the frequency of anisometropia increased with time, the difference in SE between eyes tended to remain stable.     

A cohort study of incident myopia in Singaporean children

PURPOSE: To determine the risk factors of incident myopia in a school-based cohort study in Singaporean children. METHODS: A 3-year prospective cohort study was conducted in Singaporean school children aged 7 to 9 years in three schools at entry. Chinese children without myopia at baseline (n = 994) were included in the analysis. The main outcome was incident myopia, defined as spherical equivalent (SE) at least -0.75 D based on cycloplegic autorefraction. Other definitions of incident myopia, at least -0.5 D and at least -1.0 D, were also assessed. RESULTS: After controlling for school, age, gender, income, reading in books per week and intelligence quotient (IQ) test scores, we found the relative risk (RR) of incident myopia defined as -0.75 D to be 1.55 (95% confidence interval [CI] 1.18-2.04) for two versus no myopic parents. The multivariate RR of myopia for IQ in the third versus first tertile was 1.50 (95% CI, 1.19-1.89). However, the RR of incident myopia was 1.01 (95% CI, 0.97-1.05) for every unit increase in books read per week. Similar results were obtained with definitions of -0.5 and -1.0 D for incident myopia. CONCLUSIONS: These data provide new prospective evidence of essential links between parental myopia, IQ scores and subsequent myopia development. However, reading in books per week was not associated with incident myopia.     

Temporal variations in myopia progression in Singaporean children within an academic year.

PURPOSE: Excessive nearwork is believed to be associated with myopia development and progression. To investigate this further, we studied refractive error changes and their correlation with nearwork in a cohort of grade school children in Singapore. METHODS: Cycloplegic autorefraction was performed 5 times over 10 months on 168 children aged 7, 9, and 12 years who were further divided into myopic and nonmyopic subgroups based in their initial refractive errors. Information about nearwork was obtained through diaries filled out over 24 h at the commencement of the study. RESULTS: Myopia progression was high (overall mean: -0.87 D per year) and largely linear throughout the year, but significantly higher rates were seen after the final school examinations in 7-year-old myopes and nonmyopes. Overall, myopic groups exhibited higher progression rates than nonmyopic groups, although 33.6% of subjects from the latter groups had become myopic by the end of the study. Nearwork scores derived from the diaries were generally not well correlated with overall myopia progression. CONCLUSIONS: The tendency for myopia progression rates to increase after the final school examinations in 7-year-olds is interpreted as a delayed effect of the intense nearwork associated with preparing for them. The timing of nearwork-diary data collection at the beginning of the study could be responsible for the poor correlation between these data and overall myopia progression rates.     

Factors related to the progression of myopia in Singaporean children.

PURPOSE: To examine the possible factors related to the progression of myopia in Singapore children. METHODS: One hundred fifty-three Singapore children aged 6 to 12 years were recruited to participate in a concurrent cohort study of the risk factors for the progression of myopia. Socioeconomic status, outdoor activity, and near-work activity were documented in a face-to-face clinic interview. The changes in cycloplegic subjective refraction and autorefraction were ascertained with the use of a Nidek ARK 900 over a 2-year period. RESULTS: The average rate of progression of myopia as measured by subjective refraction was -0.59 D per year (95% confidence interval -0.52, -0.66). Younger children and children who were more myopic at the beginning (refractive error worse than -2.0 D) of the study had higher myopia progression rates. CONCLUSIONS: Myopia progression was faster for younger children and for children who had more severe myopia at baseline. Socioeconomic status and near-work activity were not related to myopia progression.     

Ethnicity-specific prevalences of refractive errors vary in Asian children in neighbouring Malaysia and Singapore

AIM: To compare the prevalences of refractive errors in Malay, Chinese and Indian children in Malaysia and Singapore. METHODS: Children aged 7-9 years from three schools in the Singapore Cohort study of the Risk factors for Myopia (n = 1962) and similarly aged children from a random cluster sample in the metropolitan Kuala Lumpur area in the Malaysia Refractive Error Study in Children (n = 1752) were compared. Cycloplegic autorefraction was conducted in both countries. RESULTS: The prevalence of myopia (spherical equivalent of at least -0.5 diopters (D) in either eye) was higher in Singapore Malays (22.1%) than in Malays in Malaysia (9.2%; 95% confidence interval (CI) 11.2 to 14.7; p<0.001). Similarly, Singapore Chinese (40.1%) had higher prevalences than Malaysian Chinese (30.9%; 95% CI 1.5 to 16.9). Singapore Indians had a higher prevalence (34.1%) than Malaysian Indians (12.5%; 95% CI 17.4 to 25.9). The multivariate odds ratio of astigmatism (cylinder at least 0.75 D in either eye) in Singapore Malays compared with Malaysian Malays was 3.47 (95% CI 2.79 to 4.32). Ethnicity-specific hyperopia rates did not differ in Singapore and Malaysia. CONCLUSION: The ethnicity-specific prevalences of myopia in Singapore Malays, Chinese and Indians are higher than those in Malaysian Malays, Chinese and Indians. As Malays, Chinese and Indians in Malaysia have genetic make-up similar to that of Malays, Chinese and Indians in Singapore, environmental factors may contribute to the higher myopia rates.     

Incidence and progression of astigmatism in Singaporean children

PURPOSE: This study investigated the incidence and progression, as well as factors associated with changes in astigmatism in school children. METHODS: This was a prospective cohort study. Children 7 to 9 years of age, of Chinese, Malay, and Asian Indian ethnicity, were examined annually over a 4-year period. Cycloplegic autorefraction was performed. A questionnaire was used to evaluate risk factors for incidence and progression of astigmatism. RESULTS: The cumulative 3-year incidence rate of astigmatism was 33.6% (cylinder power of 0.5 D or worse) or 11.5% (cylinder power of 1.0 D or worse). Myopic children had a higher incidence rate of astigmatism than nonmyopes (P <0.001). The mean J0 change per year was 0.012 D (95% CI: 0.007-0.018), whereas J45 did not show a significant change each year (mean, 0.001 D per year). Chinese children had greater worsening of J0 per year (P <0.001). Girls also had significantly greater progression of J0 than did boys (P <0.001). Similarly, myopia at baseline (P <0.001) and the hours of computer use (P=0.049) were associated with a greater progression rate of J0. J0 tended to improve in children with compound hyperopic astigmatism, worsen in children with compound myopic astigmatism, and remain stable in mixed astigmatics. CONCLUSIONS: Although there was minimal progression of astigmatism in school age children (0.44-0.53 D) over this period of follow-up, incident cases of astigmatism (>1.0 D) were not uncommon. The progression rate of astigmatism was affected by the ethnicity, presence of myopia, axis, and subtype of astigmatism.     

Nine-year incidence of lens opacities in the Barbados Eye Studies

OBJECTIVE: To provide 9-year cumulative incidence of age-related lens opacities in a predominantly black population. DESIGN: Population-based cohort study, after 9 years of follow-up (n = 2793; 81% participation). MAIN OUTCOME MEASURES: Nine-year cumulative incidence and progression of lens opacities, by type, based on the Lens Opacities Classification System II at the slit lamp. RESULTS: Black participants had a higher 9-year incidence of overall lens changes than white participants (age- and gender-adjusted relative risk [RR], 1.8; 95% confidence interval [CI], 1.2-2.8), as well as of cortical opacities (RR, 3.2; 95% CI, 1.7-6.2). In black participants, incidence rates of any cortical and any nuclear opacities were 33.8% and 42.0%, respectively, and higher than for any posterior subcapsular (PSC) opacities (6.3%). The incidence increased with age for all 3 types, and women had a higher risk of cortical and nuclear opacities (P<0.05). Single cortical opacities were the most frequent type to develop by the 9-year follow-up (23.2%), followed by nuclear-only opacities (17.1%) and mixed opacities (15.3%). Progression rates of pre-existing opacities were 22.0% for cortical, 17.8% for nuclear, and 25.8% for PSC opacities. CONCLUSIONS: The 9-year follow-up of this cohort indicated a high incidence and progression of cortical and nuclear opacities, highlighting the public health importance of cataract in black populations.     

Refractive errors and 10-year incidence of age-related maculopathy

PURPOSE: To describe the relationship of refractive errors to the 10-year incidence of age-related maculopathy (ARM) in a defined white population. METHODS: Persons aged 43 to 86 years of age in Beaver Dam, Wisconsin, were invited for a baseline examination from 1988 through 1990, and follow-up examinations 5 and 10 years later (n = 3684). Refraction was measured at baseline, with myopia defined as a spherical equivalent of -1.00 D or less, emmetropia as -0.75 to +0.75 D and hyperopia as +1.00 D or more. At each examination, signs of ARM were ascertained from grading stereoscopic color fundus photographs based on a standard protocol. The association between baseline refractive status and the 10-year incidence and progression of ARM was analyzed. RESULTS: The 10-year cumulative incidence for early ARM was 7.1%, 7.7%, and 11.7%, in eyes with myopia, emmetropia, and hyperopia, respectively. The corresponding 10-year cumulative incidence for late ARM was 0.3%, 0.8%, and 2.2%. When age was controlled for, there was no association between myopia and incident early (relative risk [RR] 1.0, 95% confidence interval [CI], 0.7-1.3) and late (RR 0.5, 95% CI, 0.2-1.5) ARM. Similarly, after controlling for age, hyperopia was not associated with incident early (RR 0.9, 95% CI, 0.7-1.1) or late (RR 1.2, 95% CI, 0.6-2.3) ARM. CONCLUSIONS: These prospective population-based data provide no evidence of an association between refractive errors and risk of ARM.     

Nine-year refractive changes in the Barbados Eye Studies

PURPOSE: To describe 9-year changes in refractive errors and estimate incidence of myopia and hyperopia in adults of African-descent, along with associated risk factors. METHODS: The 9-year follow-up of the Barbados Eye Studies (1997-2003) reexamined 2793 surviving cohort members (81% participation). Refractive errors were determined by automated refraction. Myopia/hyperopia were defined as spherical equivalent < -0.5 diopters (D)/> +0.5 D, and the cutoff for moderate-high myopia/hyperopia was 3.0 D. Incidence rates of myopia/hyperopia were estimated by the product-limit approach, based on eyes without such conditions at baseline. Risk factors were evaluated by logistic regression in discrete time hazard models. RESULTS: Nine-year refraction changes varied by age. Persons aged 40 to 49 years experienced hyperopic shifts (median, +0.38 D), whereas persons > or =60 years had myopic shifts (median, -0.75D). Overall 9-year incidence was 12.0% for myopia and 29.5% for hyperopia; rates were 3.6% and 2.0% for moderate-high myopia and hyperopia, respectively. Myopia risk increased with age, baseline nuclear lens opacities (risk ratio [RR] = 1.7; 95% confidence interval [CI]: 1.01-2.9), glaucoma (RR = 6.0, 95% CI: 3.9-9.3), and ocular hypertension (RR = 2.0, 95% CI: 1.3-3.0), while cortical lens opacities decreased risk (RR = 0.6, 95% CI: 0.4-0.9). Incidence of moderate-high myopia was also related to baseline age, nuclear opacities, glaucoma, male gender (RR = 1.7, 95% CI: 1.0-2.8), and diabetes history (RR = 1.9, 95% CI: 1.01-3.5). Hyperopia risk decreased with older age, male gender, and glaucoma diagnosis. CONCLUSIONS: Refractive errors continue to develop frequently in older adults. Nuclear lens opacities, glaucoma, and diabetes increase the risk of older-onset myopia, a result of public health relevance to this and similar African-origin populations.     

Nearwork in early-onset myopia

PURPOSE: To determine the relationship of nearwork and myopia in young elementary school-age children in Singapore. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.     

Relation between work and myopia in Singapore women.

BACKGROUND: Work and related activities may be connected to myopia development and progression. We investigated the relationship between working activities and the onset as well as worsening of myopia. METHODS: Information on the working status of the mothers of 374 children, the number of hours of close-up work activity, and whether the mother was short-sighted, was obtained by a face-to-face interview. In addition, a subsample of 84 mothers was interviewed over the telephone and asked whether the myopia occurred in adulthood and, if so, the age of cessation of myopia. RESULTS: The adjusted odds ratio for myopia in working women was 1.9 [95% confidence interval (CI) 1.2 to 3.2] and the adjusted odds ratio for high myopia (> -6.0 D) was 1.6 (95% CI 0.8 to 3.0). Women who were working also had higher rates of adult-onset myopia, odds ratio 4.4 (95% CI 0.9 to 21.2), and a later age of cessation of myopia than nonworking women. CONCLUSIONS: In our study, work was related to myopia in Singapore women. Work may be a surrogate for another risk factor, close-up work activities such as reading, writing, and computer use.     

Eye growth changes in myopic children in Singapore

AIMS: To assess the longitudinal changes in biometric parameters and associated factors in young myopic children aged 7--9 years followed prospectively in Singapore. METHODS: Children aged 7--9 years from three Singapore schools were invited to participate in the SCORM (Singapore Cohort study Of the Risk factors for Myopia) study. Yearly eye examinations involving biometry measures were performed in the schools. Only myopic children (n=543) with 3 year follow up data were included in this analysis. RESULTS: The 3 year increases in axial length, anterior chamber depth, lens thickness, vitreous chamber depth, and corneal curvature were 0.89 mm, -0.02 mm, -0.01 mm, 0.92 mm, and 0.01 mm, respectively. Children who were younger, female, and who had a parental history of myopia were more likely to have greater increases in axial length. After adjustment for school, age, sex, race, parental myopia and reading in books per week, the age (p<0.001), sex (p=0.012), and parental myopia (p=0.027) remained significantly associated with the 3 year change in axial length. Reading in books per week, however, was not associated with axial length change. Children with faster rates of progression of myopia had greater increases in axial length (Pearson correlation coefficient (r)=-0.69) and vitreous chamber depth (r=-0.83). CONCLUSIONS: The 3 year change in axial length of Singapore children aged 7--9 years at baseline was high and greater in younger children, females, and children with a parental history of myopia. Myopia progression was driven largely by vitreous chamber depth increase.     

Necessity of cycloplegia for assessing refractive error in 12-year-old children: a population-based study

PURPOSE: To compare pre- and postcycloplegic autorefraction in two separate age samples of Australian school children. DESIGN: Population-based cross-sectional study of random cluster samples. METHODS: Autorefraction was performed before and after cycloplegia, using 1% cyclopentolate, in the right eyes of 2,233 12-year-old and 210 6-year-old children. RESULTS: The mean spherical equivalent (SEQ) difference between these measures was 0.84 diopters (D) (95% confidence interval (CI) 0.81 to 0.87 D), more hyperopic in post- than precycloplegic autorefractive assessments in the 12-year-old children and 1.18 D (95% CI 1.05 to 1.30 D) more hyperopic in the 6-year-old children. Precycloplegic autorefraction substantially overestimated the proportion of children with myopia, misclassifying 17.8% aged 12 years and 9.5% aged 6 years. Conversely, precycloplegic autorefraction did not detect moderate to high hyperopia in 2.28% of 12-year-olds and 17.14% of 6-year-olds. CONCLUSIONS: Our findings reinforce the importance of using cycloplegic autorefraction in children up to age 12 years.     

Prevalence, incidence, and progression of myopia of school children in Hong Kong

PURPOSE: To determine the prevalence, incidence, and progression of myopia of Chinese children in Hong Kong. METHODS: A cross-sectional survey was initially conducted. A longitudinal follow-up study was then conducted 12 months later. RESULTS: A total of 7560 children of mean age 9.33 (95% confidence interval [CI] = 9.11-9.45; range, 5-16) participated in the study. Mean spherical equivalent refraction (SER) was -0.33 D (SD = 11.56; range, -13.13 to +14.25 D). Myopia (SER 相似文献   

Anisometropia in Singapore school children

PURPOSE: To report the prevalence rates of anisometropia in a school population and determine the relative contribution of refractive power and axial length to the measured anisometropia. DESIGN: Population-based cross-sectional study. METHODS: Autorefraction, keratometry, and ultrasonography studies were made. Setting: Three schools, located on the eastern, northern, and western part of Singapore. STUDY POPULATION: In all, 1,979 children aged 7 to 9 years were recruited for this study. The study sample included Chinese (n = 1,481), Malay (n = 324), and Asian Indian (n = 174) children; 720 subjects have myopia (spherical equivalent <= -0.5 diopters) in at least one eye. MAIN OUTCOME MEASURE: Anisometropia. RESULTS: The prevalence rates of anisometropia, in terms of spherical equivalent (SE) difference of at least 1.5 diopters and 2.0 diopters were 1.57% (95% confidence interval [CI]: 1.1, 2.2) and 1.01% (95% CI: 0.6, 1.6), respectively. The prevalence rate of anisometropia (at least 2.0 diopters) among the children with at least one myopic eye was 2.4% (95% CI: 1.4, 3.8), whereas in those without any myopic eyes, the prevalence rate was only 0.2% (95% CI: 0.06, 0.8). The spherical equivalent difference between the right and left eyes was positively correlated with the difference in axial lengths (P <.001). The difference in corneal refractive power is not statistically different between the anisometropic and the nonanisometropic children. CONCLUSIONS: The anisometropia prevalence rate in a childhood population with a relatively high prevalence of myopia was reported. The origin of the anisometropia is axial, and these results suggest that the differential rate of elongation between the two eyes of nonmyopic subjects results in anisometropia.     

角膜塑形镜控制青少年近视有效性及安全性的Meta分析

目的 就角膜塑形镜对青少年近视患者的有效性及安全性进行Meta分析。方法 循证医学研究。以2017年1月前发表的角膜塑形镜控制儿童近视进展有效性和安全性的临床资料为目标,检索Medline及中国知网、万方数据库。通过Stata 11.0对文献进行Meta分析。计算1年和2年时间的眼轴长度改变的加权均数差（WMD）和不良反应发生率的比值比（OR及95%CI）,并按研究类型、种族、测量仪器等因素进行亚组分析。结果 共纳入14项研究,病例共2 563例,其中塑形镜组1 339例,框架镜组1 224例。Meta分析结果显示：2年观察中,塑形镜组和框架镜组眼轴的变化量有显著差异,WMD=-0.361,95%CI：-0.604~0.118,1年观察中,塑形镜组和框架镜组眼轴的变化量有显著差异,WMD=-0.356,95%CI：-0.610~-0.102。随访1年后塑形镜组近视控制率为66.6%,随访2年后为51.3%[近视控制率=（塑形镜组眼轴变化量-框架镜组眼轴变化量）/框架镜组眼轴变化量]。2年随访时间内,塑形镜组和框架镜组不良反应发生率的OR=6.408,95%CI：2.460~16.688。结论 角膜塑形镜是一个有效且相对安全的控制儿童近视进展的方法。     

Prevalence and risk factors for refractive errors in adult Chinese in Singapore

PURPOSE: To determine the epidemiology of refractive errors in an adult Chinese population in Singapore. METHODS: A disproportionate, stratified, clustered, random-sampling procedure was used to select names of 2000 Chinese people aged 40 to 79 years from the 1996 Singapore electoral register in the Tanjong Pagar district in Singapore. These people were invited to a centralized clinic for a comprehensive eye examination, including refraction. Refraction was also performed on nonrespondents in their homes. Myopia, high myopia, and hyperopia were defined as a spherical equivalent (SE) in the right eye of less than -0.5 D, less than -5.0 D, and more than +0.5 D, respectively. Astigmatism was defined as less than -0.5 D of cylinder. Anisometropia was defined as a difference in SE of more than 1.0 D between the two eyes. Only phakic eyes were analyzed. RESULTS: From 1717 eligible people, 1232 (71.8%) were examined. Adjusted to the 1997 Singapore population, the overall prevalence of myopia, hyperopia, astigmatism, and anisometropia was 38.7% (95% confidence interval [CI]: 35.5, 42.1), 28.4% (95% CI: 25.3, 31.3), 37.8% (95% CI: 34.6, 41.1), and 15.9% (95% CI: 13.5, 18.4), respectively. The prevalence of high myopia was 9.1% (95% CI: 7.2, 11.2), with women having significantly higher rates than men. The age pattern of myopia was bimodal, with higher prevalence in the 40 to 49 and 70 to 81 age groups and lower prevalence between those age ranges. Prevalence was reversed in hyperopia, with a higher prevalence in subjects aged 50 to 69. There was a monotonic increase in prevalence with age for both astigmatism and anisometropia. Increasing educational levels, higher individual income, professional or office-related occupations, better housing, and greater severity of nuclear opacity were all significantly associated with higher rates of myopia, after adjustment for age and sex. CONCLUSIONS: The results indicate that whereas myopia is 1.5 to 2.5 times more prevalent in adult Chinese residing in Singapore than in similarly aged European-derived populations in the United States and Australia, the sociodemographic associations are similar.     

Prevalence rates of refractive errors in Sumatra,Indonesia

PURPOSE: To determine the prevalence rates of myopia, hyperopia, astigmatism, and anisometropia in a prevalence survey of adults in Sumatra, Indonesia. METHODS: A population-based prevalence survey of 1043 adults 21 or more years of age was conducted in five rural villages and one provincial town of the Riau Province, Sumatra, Indonesia. A one-stage household cluster sampling procedure was used wherein 100 households were selected from each village or town. Refractive error measurements were obtained with one of two handheld autorefractors. Household interviews were conducted to obtain information on relevant lifestyle risk factors. RESULTS: The age-adjusted overall prevalence rates of myopia (SE [spherical equivalent] at least -1.0 D), hyperopia (SE of at least +1.0 D), astigmatism (cylinder of at least -1.0 D), and anisometropia (SE difference of +1.0 D) were 26.1% (95% confidence interval [CI]: 23.4-28.8), 9.2% (95% CI: 7.4-11.0), 18.5% (95% CI: 16.2-20.8), and 15.1% (95% CI: 12.9-17.4), respectively. The age-adjusted overall prevalence rate of high myopia (SE at least -6.0 D) was 0.8% (95% CI: 0.2-1.5). In a multiple logistic regression model, myopia rates varied with age and increased with income. Hyperopia, astigmatism, and anisometropia rates were independently higher in older adults. CONCLUSIONS: The prevalence rates of myopia in provincial Sumatra are higher than the rates in white populations, but lower than the rates in other urbanized Asian countries such as Singapore. The prevalence rate of high myopia is lower than in most other populations, and other refractive errors are common.     

The progression of refractive error in school-age children: Shunyi district,China

PURPOSE: To assess the progression of refractive error and the incidence of myopia in school-age children in the Shunyi District of Beijing, China. DESIGN: A longitudinal cohort study. METHODS: A population-based sample of 4,662 children initially examined in 1998 at ages 5 to 13 years was reexamined between September and November, 2000. Refractive error was measured under cycloplegia with autorefraction. Age, sex, and baseline refractive error were evaluated as risk factors for progression. RESULTS: In 28.5 months, the average change in refractive error was -0.42 diopters (standard deviation, 0.68) in right eyes. Myopic shift of refractive error was associated with female sex, older age, and higher myopic or hyperopic refractive error at baseline. The average change in astigmatic error was essentially zero, with significant change in both directions more likely among those with higher baseline astigmatism. Findings were similar for left eyes. The cumulative incidence of myopia, defined as a spherical equivalent refractive error of -0.50 diopters or more in either eye, among initial emmetropes and hyperopes was 14.1% (95% confidence interval [CI], 11.8%-16.5%) for male and 23.5% (95% CI, 20.8%-26.1%) for female subjects. Myopia incidence increased sixfold to sevenfold between baseline age 5 and 12, before decreasing at age 13, for both male and female subjects. CONCLUSIONS: In the design of cost-effective programs for the periodic screening and treatment of uncorrected refractive error, children initially found to require refractive correction should be targeted for relatively frequent rescreening, as should girls and older children. Further study is required to better understand environmental and genetic risk factors for myopia development and progression.     

Incidence and progression rates of age-related maculopathy: the Rotterdam Study

PURPOSE: To describe the incidence rate of age-related macular degeneration (AMD) and the progression rates of early stages of age-related maculopathy (ARM), and to study the hierarchy of fundus features that determine progression. METHODS: A group of 4953 subjects aged 55 years and older living in Rotterdam, The Netherlands, was studied at baseline and at 2-year follow-up to determine the incidence of neovascular and atrophic AMD. A subgroup of 1244 subjects was studied for progression of early stages of ARM. Fundus transparencies were graded for features of ARM using the International Classification System. ARM was stratified in four exclusive stages, according to type of drusen and presence of pigmentary irregularities. RESULTS: The overall 2-year cumulative incidence of AMD was 0.2%, increasing to 1.8% in subjects of 85 years and older. Of those in the early stages, one fourth showed progression to a more severe stage. The most important predictors for progression were more than 10% of macular area covered by drusen (odds ratio [OR] 5.7, 95% confidence interval [CI] 2.9-11.3), presence of depigmentation (OR 4.0, 95% CI 2.5-6.4), and hyperpigmentation (OR 3.4, 95% CI 2.1-5.4). CONCLUSIONS: The incidence of AMD appears to be lower in The Netherlands than in the United States. Progression of early ARM stages occurs in a distinct pattern at a stable rate, with a large area of drusen and presence of pigmentary changes as the most important predictors.