佛山市学龄前儿童近视眼流行病学调查及相关因素分析

目的:调查学龄前儿童近视眼的流行病学状况、分析相关因素,为早期预防近视提供一定依据。方法:随机选取佛山市五区属下幼儿园5182例3~6岁学龄前儿童作为调查对象。使用尼德克AR-20快速电脑验光仪对所选儿童进行屈光筛查。可疑近视者和屈光度≤+2.00D者予10g/L阿托品眼膏涂双眼3d,由专人进行视网膜检影。确诊为近视及屈光度≤+2.00D的儿童由专人进行近视相关因素调查。确诊为近视者经适当的屈光矫正后,每6mo进行1次屈光复查,按要求进行为期1a的随访。结果:学龄前儿童近视眼患病率为1.95%,城区2.10%,农村1.80%;其中3~<4岁占0.98%,4~<5岁占1.96%,5~6岁占2.45%。相关因素分析:学龄前儿童近视眼发生与近亲近视史密切相关。城区与农村学龄前儿童近视眼发病情况无显著性差异。结论:学龄前儿童近视在临床上并不少见,不容忽视。     

锦州市3～6周岁儿童屈光状态筛查及相关因素分析

目的：调查锦州市3～6周岁儿童的双眼屈光状态,分析相关影响因素,为屈光不正的防治提供依据。

方法：采用整群随机抽样法抽取锦州市30所幼儿园2 848名学龄前儿童,应用美国伟伦公司生产的SureSight视力筛查仪进行屈光检查,并向受检者家长发放问卷调查表进行相关因素的调查,对调查结果进行统计学分析。

结果：学龄前儿童2 848名参与调查,2 565人合格完成问卷调查表,完成率90.06%,整体屈光异常检出率为18.13%,屈光异常检出率四个年龄组分别为：11.84%,16.28%,20.72%,25.62%,趋势χ²检验(χ²=47.085,P<0.01),表明屈光异常检出率有随年龄增加而增高的趋势。屈光异常检出率男童21.83%、女童13.54%,差异有统计学意义(χ²=29.378,P<0.01)。经非条件Logistic回归分析,父、母文化程度、母亲生育年龄、早产、出生有窒息史、出生体质量、父亲屈光状态、近距离用眼时间、少吃蔬菜水果等因素的OR值分别为：2.638,2.380,2.316,5.891,9.675,3.146,2.079,1.241,6.731。

结论：随着年龄的增长,屈光异常检出率呈现增高趋势。男童的屈光异常检出率明显高于女童。父母低文化程度、高龄产妇、出生有窒息史、早产、体质量低于2 000g或高于4 000g、父亲屈光异常、长时间近距离用眼、少食蔬菜水果是屈光异常的危险因素。     

青少年儿童屈光不正4 771例分析

目的:探讨视力低常青少年儿童屈光状态的分布规律,力争在儿童青少年的视觉发育敏感期早发现,早治疗。方法:除外屈光不正以外的其他眼疾的情况下,在睫状肌麻痹下检影验光后进行统计分析。结果:在9530眼中,近视眼4439只,远视眼4417只,其中近远视眼中均以复性近远视散光眼最多,各占56.50%,83.61%。年龄与屈光不正度数之间进行统计学分析有显著差异﹙P<0.01),随年龄增长,近视屈光度增加,远视屈光度减少。在7015只散光眼中,学龄前组散光发生率最高占89.05%,且以低度散光为主。随年龄增长,呈逐渐下降趋势。结论:在防治近视眼的工作中,必需在睫状肌麻痹下准确检影验光方可了解真实的屈光状态,再采取不同的防治措施,了解儿童散光眼的散光状态对于合理矫治儿童散光十分重要。     

屈光形式与弱视发生风险分析

目的观察屈光不正性弱视儿童的屈光特点,分析不同屈光形式发生弱视的风险。方法病例对照研究。弱视组为我院就诊屈光不正性弱视儿童273例(400眼);对照组为幼儿园体检视力正常儿童200例(400眼)。比较两组各种屈光形式的分布,采用多因素Logistic回归分析,明确屈光不正性弱视发病的主要危险因素。结果 logistic回归分析显示,远视(>+4.00D)(OR=305.07,95%CI:94.64,983.38:P<0.001)、散光(>2.00D)(OR=114.45,95%CI:58.32,224.57;P<0.001)、远视性屈光参差(OR=17.19,95%CI:6.71,44.01;P<0.001)在两组间的差异具有统计学意义。结论导致弱视的屈光不正主要是高度远视(>+4.00D)、散光(>2.00D)和远视性屈光参差。对导致弱视的高危屈光不正要尽早予以矫正。     

儿童视光学问题讨论(续)

6 正确认识儿童屈光与视力的关系( 1 )远视与远视眼 ,正视与正视眼及近视与近视眼为不同概念。( 2 )远视力正常不等于屈光正常 ,远视力低常不等于都是近视屈光。( 3)视力定性检查 :通过负荷试验可以测知不同视力下的可能屈光。( 4 )视力正常眼静止状态 (调节麻痹 )下可表现有远视眼 (最多 ) ,正视眼 (较少 ) ,近视眼 (最少 )。7 儿童近视眼( 1 )儿童屈光度有以下三种情况之一者 ,可发展成近视眼 :眼轴不成比例的延长 ;角膜或晶状体屈光力改变 ,而不能适当代偿者 ;原先存在的远视眼屈光度较低者。( 2 )儿童期出现的近视眼总是发展的。有家族…     

学龄前儿童假性近视眼292例分析

目的了解学龄前儿童假性近视眼的性质与特点。方法视光门诊中"近视眼"(远视力<1.0、近视力≥1.0、原瞳验光为近视的)4~6岁学龄前儿童292名515眼。除眼科常规检查外,均用1%阿托品眼膏散瞳,每晚涂眼1次,共7天。1周后由专职人员验光。结果292人515眼中,远视478眼,占92.81%,正视11眼(2.14%),混合散光26眼(5.05%)。结论学龄前儿童假性近视眼的屈光基础为远视眼,为调节导致。学龄前儿童应用阿托品散瞳验光。     

屈光参差性弱视儿童视力与立体视的关系

目的探究相同屈光参差范围内不同类型屈光参差性弱视儿童的视力与立体视情况,以及视力、屈光参差类型对拥有立体视与否的影响。方法回顾性研究。收集56例屈光参差性弱视儿童和52例伴有斜视的屈光参差性弱视儿童以及20例正常儿童相应检查数据,检查包括矫正视力、屈光程度、随机点动态2阶粗糙立体视。采用多元方差分析3类儿童的视力差异,统计立体视分布情况,运用非条件logistic回归分析视力与屈光参差类型对拥有立体视与否的影响。结果单纯屈光参差性弱视儿童与伴有斜视的屈光参差性弱视儿童的视力差异无统计学意义（F=3.58,P=0.0314,校正α=0.016）。单纯及伴有斜视的屈光参差性弱视儿童粗糙立体视拥有率分别为96%,71%。在双眼视力一致的条件下,伴有斜视的屈光参差性弱视与单纯屈光参差性弱视儿童相比,拥有2阶立体视的OR估计值为0.132（95%CI：0.034~0.503）。在屈光参差类型一致的条件下,高、中双眼视力平衡度与低双眼视力平衡度相比,拥有2阶立体视的OR估计值分别为5.161（95%CI：0.868~30.675）和3.939（95%CI： 0.920~16.858）。结论相同屈光参差程度范围中不同类型屈光参差性弱视儿童的视力差异不明显;伴有斜视的屈光参差性弱视儿童立体视缺损的可能性更高,并且双眼不平衡度越高引起的立体视下降越明显。     

干眼与A型性格的相关性研究

目的:探讨A型性格与干眼的相关性,为干眼的预防和诊治提供新思路.方法:本研究采用病例对照研究的方法,按照年龄、性别1:1匹配,选取100例干眼新发患者为干眼组,100例健康志愿者为对照组.使用"A型性格问卷调查表"统一调查获取临床资料,先用χ2检验对干眼组与健康对照组的性格类型分布进行比较,再运用单因素和多因素条件Logistic回归分析统计数据.结果:干眼组与对照组性格类型分布情况比较,差异有统计学意义(χ2=6.494,P=0.011),单因素Logistic回归分析中A型性格者患干眼的OR值为2.296(95%CI:1.202~4.384,P=0.012);每天面对视频终端时间≥6h患干眼的OR值为2.992(95%CI:1.668~5.369,P<0.01);长期处于空调环境中患干眼的OR值为2.631(95%CI:1.472~4.702,P=0.001).多因素条件Logistic回归分析中A型性格者患干眼的OR值为2.659(95%CI:1.335~5.295,P=0.005);每天面对视频终端时间≥6h患干眼的OR值为2.264(95%CI:1.166~4.396,P=0.016);长期处于空调环境中患干眼的OR值为2.053(95%CI:1.048~4.020,P=0.036).结论:A型性格、每天面对视频终端时间≥6h、长期处于空调环境中可能是干眼发生的独立危险因素.     

周边屈光对近视的影响

周边屈光,即周边视网膜的屈光状态,指与视轴成一定的夹角,距注视点30°以外周边视野内的屈光状态。动物及人类研究表明,周边屈光与近视存在密切关系。周边相对远视的屈光度数能影响中央近视度数,不同年龄阶段人群周边相对远视的屈光状态均呈现为近视发生的危险因素,并可能为近视眼屈光度进展的危险因素之一。周边近视离焦可能阻止眼轴增长,从而控制近视进展、促进视力恢复。我们归纳近年来周边屈光对近视的发生、发展及控制的影响,及其与眼球形态、调节、遗传的关系进行综述。     

学龄前儿童斜视的危险因素分析

目的:探讨学龄前儿童斜视的风险因素。方法:回顾性分析2009-07/2015-12在武警重庆总队医院眼科就诊的学龄前儿童1926例的临床资料,其中斜视儿童纳入斜视组(n=186)和正常视力儿童纳入正常组(n=1740),对两组临床资料进行单因素和多因素Logistic分析。结果:出生体质量、Apgar评分及孕龄均是学龄前儿童斜视的独立危险因素(P<0.05),其中Apgar评分的风险最高[OR(95%CI):6.336(2.180~18.416)]。结论:出生体质量、Apgar评分及孕龄均是学龄前儿童斜视的独立危险因素,孕妇需注意产前的安胎保健工作,尽量足月分娩,以避免儿童斜视的危险因素,同时定期加强学龄前儿童的视力筛查并做好相应的干预措施。     

数码折射系统在学龄前儿童弱视危险因素筛查中的应用研究

目的:探讨数码折射系统在学龄前儿童弱视危险因素筛查中的可行性。方法:使用数码折射系统对469例10～70月龄的学龄前儿童进行屈光状态及弱视危险因素的筛查,再行眼科常规散瞳验光检查。结果:在检测弱视危险因素包括远视≥+2.75D,近视≥-1.50D,散光≥1.25D,屈光参差≥2.00D,眼位偏斜≥5°,屈光间质混浊≥1.5mm中,数码折射系统对斜视和屈光间质混浊的检出率为100%,对中高度远视的检出率为88.0%,对近视的检出率为93.4%,对散光的检出率为87.5%,对屈光参差的检出率为80.0%。结论:数码折射系统可用于学龄前儿童弱视危险因素的筛查,是一种安全、快速、有效的儿童眼病筛查方法。     

杭州市拱墅区公立小学三年级小学生近视患病率及相关因素分析

探讨近视初发阶段公立小学学生近视的患病率及危险因素，为青少年近视的防控提供思路。方法：横断面研究。对2017年11月至2018年2月期间杭州市拱墅区1 004名三年级小学生进行近视相关问卷调查以及眼部参数检查。研究对象在睫状肌麻痹验光后，等效球镜度（SE）≤-0.5 D 归入近视组，SE>-0.5 D归入非近视组；组间参数比较采用秩和检验和卡方检验，同时以近视/未近视组为因变量分别与其他协变量进行二元逻辑回归分析。结果：杭州市拱墅区公立三年级小学生近视患病率为32.3%，男生的患病率为29.2％，女生的患病率为35.4%，性别差异有统计学意义（χ2 =4.43，P=0.035）；第2季度出生的研究对象近视患病率较第1季度出生（χ2 =4.30，P=0.041）以及第 4季度（χ2 =12.06，P<0.001）出生的高。以近视组/非近视组为因变量作二元逻辑回归显示：父亲近视程度（OR=1.509，P<0.001）、母亲近视程度（OR=1.360，P<0.001）、女生（OR=1.329，P=0.049）、放学后视近时间（OR=1.467，P=0.034）、寒暑假视近时间（OR=1.352，P<0.001）、放学后视中距离时间（OR=1.626，P=0.045）和寒暑假视中距离时间（OR=1.860，P<0.001）为近视发生的危险因素，而放学后户外活动时间（OR=0.618，P<0.001）、寒暑假户外活动时间（OR=0.823，P=0.004）为近视发生的保护因素。结论：在杭州市拱墅区近视初发阶段的小学生中，女生近视患病率高于男生。出生于第 2季度的学生近视患病率比出生于第1季度和第4季度的学生高一些。过多的近、中距离和过少的户外活动是导致近视发病的原因，学习日之外，寒暑假期间也应该减少近、中距离用眼并增加户外活动的时间。     

The anti-inflammatory regulation of calcitonin gene-related peptide in mouse Aspergillus fumigatus keratitis

AIM: To analyze the impact of calcitonin gene-related peptide (CGRP) in mouse keratitis after Aspergillus fumigatus (A. fumigatus) infection. METHODS: C57BL/6 mice were treated subconjunctivally with different concentrations of exogenous CGRP, and BALB/c mice were treated with CGRP8-37 (a CGRP antagonist) before corneas were infected with A. fumigatus. The cornea was assessed under the slit-lamp and the clinical score was recorded. The mRNA levels of IL-1β, TNF-α, IL-6, and MIP-2 were detected by quantitative real-time polymerase chain reaction (PCR), while the protein level of IL-1β was determined by Western blotting. In vitro, RAW264.7 cells were used to investigate NLRP3 and IL-1β expression induced by A. fumigatus after the pretreatment of exogenous CGRP or CGRP8-37. Cytokines expression in RAW264.7 cells was evaluated by real-time PCR and Western blotting. RESULTS: Using exogenous CGRP resulted in down-regulated synthesis of IL-1β and MIP-2 stimulated by A. fumigatus in C57BL/6 mice keratitis, and the synthesis of IL-1β, MIP-2 and IL-6 was up-regulated in BALB/c mice corneas after the pretreatment with CGRP8-37. Pretreatment with exogenous CGRP and CGRP8-37 did not influence TNF-α mRNA levels either in BALB/c or C57BL/6 mice keratitis. The levels of NLRP3 and IL-1β were both reduced in A. fumigatus stimulated-macrophages after treatment with exogenous CGRP. And CGRP8-37 pretreatment would increase NLRP3 and IL-1β levels. CONCLUSION: CGRP may alleviate the inflammatory reaction in mice keratitis after infection with A. fumigatus. The anti-inflammatory effect may be related to the inhibition of NLRP3 expression by CGRP.     

上海市区学龄前儿童屈光异常852例分析

目的:了解上海市区部分学龄前儿童屈光的异常状态及视力矫正情况。方法:视力异常学龄前儿童852例(1615眼)作散瞳验光检查,并对检查结果进行分析探讨。结果:单纯近视443眼(27.43%),复性近视散光255眼(15.79%),单纯远视287眼(17.77%),复性远视散光347眼(21.49%),混合性散光283眼(17.52%)。随着年龄的增长,就诊的学龄前近视患者逐渐增多;父母近视对学龄前儿童近视发生率的增加有影响;屈光不正大都以轻中度为主(82.43%),视力大多(80.40%)是可以矫正的。结论:学龄前儿童近视和近视散光的发生率有明显增加的趋势。     

电子产品对学龄前及学龄初期儿童近视的相关性分析

目的：探索电子产品对学龄前及学龄初期儿童近视的影响及发生发展规律,并制定合理的用眼健康指导规范,为开展防治工作打下坚实的基础。方法：回顾性分析门诊就诊的3～12岁学龄前及学龄初期儿童900例,均建立个性化档案,记录裸眼视力、验光、裂隙灯、眼底镜、斜视检查结果;记录电视、电脑、手机、iPad、写作业、课外书用眼情况。统计分析各年龄组的屈光状态、不同年龄组电子产品使用时间及其与近视的相关性。结果：裸眼视力正常者学龄前儿童多于学龄初期儿童,差异有统计学意义（ P＜0．05）;视力低常者学龄前儿童各年龄组间比较,差异无统计学意义（ P＞0．05）;近视的例数7～12岁（学龄初期）多于3～6岁（学龄前）儿童,差异有统计学意义（ P＜0．05）。电子产品的应用在6岁、10岁儿童中用眼时间叠加最多,logistic回归模型显示玩手机时间、玩电脑时间、玩iPad时间是近视的危险因素。结论：对学龄前儿童行早期筛查,健康用眼指导、建立个性化就诊档案,进行一对一个性化用眼指导;避免学习任务繁重造成用眼时间叠加,争取近视延后发生、控制近视度数增长过快。因此,减少电子产品的使用已经成为一项值得深入研究的课题。     

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.     

北京市城乡限定学校一、四年级小学生近视眼患病率及相关危险因素

目的 分析北京市城乡一、四年级小学生近视患病率情况,并探讨其相关危险因素。设计 学校为基础的横断面调查。研究对象 共调查城乡各一所学校。382名一年级和299名四年级小学生参与研究。方法 对所有学生进行眼科检查,包括视力、眼球运动、电脑自动验光、眼前段、眼球生物测量及非散瞳眼底照相。并对学生及家长进行问卷调查,包括一般项目、用眼时间、户外活动以及社会经济学因素。近视与性别、地区、用眼时间、户外活动及社会经济学因素的关系采用多元回归模型进行分析。主要指标 近视患病率及相关的危险因素。结果 按照不同的近视定义［等效球镜度（SE）≤-0.50 D,≤-1.00 D,≤-1.50 D,≤-2.00 D］,本群学生中近视患病率分别为48.1%、27.9%、17.5%和11.6%。通过多因素Logistic回归分析,近视（SE≤-1.00D）患病率与年龄（P=0.003, OR=1.45）、地区（P=0.000, OR=0.20）、父母近视情况（P=0.000, OR=2.99）、户外运动时间（P=0.013, OR=0.14）、户外休闲时间（P=0.001, OR=0.33）、户外活动时间（P=0.001, OR=0.35）、看电视时间（P=0.008, OR=0.66）、学习时间（P=0.001, OR=1.37）有关。眼轴长度与年龄（P=0.000; 标准化系数β：0.28）、身高（P=0.001; β: 0.18）、父母近视情况（P=0.03; β：0.09）、地区（P=0.000; β：-0.21）、户外活动时间（P=0.001; β:-0.16）、户外休闲时间（P=0.001; β： -0.15）、学习时间（P=0.02; β：0.10）相关。因此年龄大、城市居住、户外活动少、父母近视、学习时间长者近视患病率高、眼轴长。结论 该限定城、乡地区学龄儿童近视患病率、眼轴长度与年龄、地区、父母近视、学习时间、户外活动等相关。增加户外活动时间,可能有助于降低青少年儿童的近视患病率。（眼科,2012,21： 127-131）     

Refractive associations with cataract: the Blue Mountains Eye Study.

PURPOSE: To assess the relationship between myopia and age-related cataract in a defined older population. METHODS: A cross-sectional study of 3654 people aged 49 to 97 years was conducted in the Blue Mountains near Sydney, Australia, from 1992 through 1994. General medical, eye, and refractive history and information about confounders were collected by questionnaire. Participants had a detailed determination of refraction, and the spherical equivalent refraction of each eye was calculated. The Wisconsin Cataract Grading System was used in masked grading of slit lamp and retroillumination lens photographs, to assess presence and severity of nuclear, cortical, and posterior subcapsular (PSC) cataract. Data from both eyes were analyzed by the generalized estimating equation method, adjusting for cataract risk factors. RESULTS: Included in the analysis were 7308 eyes. A history of wearing distance glasses, excluding eyes with current hyperopic refraction, was used as a proxy for myopia. Subjects who had worn distance glasses were more likely to have nuclear cataract (odds ratio [OR] 1.3; confidence interval [CI] 1.0-2.1). After stratification by age at first wearing distance glasses, this relationship remained only for people who first wore distance glasses after age 40 years (OR 1.3; CI 1.0-1.8), which suggested a myopic refractive shift from developing nuclear opacity and was supported by the weak association found between current myopic refraction and nuclear cataract (OR 1.3; CI 1.0-1.6). Eyes with onset of myopia before age 20 years had the greatest PSC cataract risk (OR 3.9; CI 2.0-7.9). This was supported by the finding of an association between current myopic refraction and PSC cataract (OR 2.5; CI 1.6-4.1). PSC cataract was inversely associated with hyperopia (OR 0.6; CI 0.4-0.9). Refraction-related increasing odds were found between PSC cataract and myopia: low myopia (OR 2.1; CI 1.4-3.5), moderate myopia (OR 3.1; CI 1.6-5.7), and high myopia (OR 5.5; CI 2.8-10.9). High myopia was associated with PSC, cortical, and late nuclear cataract. CONCLUSIONS: Early-onset myopia (before age 20 years) may be a strong and independent risk factor for PSC cataract. The findings suggest the possibility of a dose response between levels of myopia and PSC cataract. Nuclear cataract was associated with presumed acquired myopia, whereas high myopia was associated with all three types of cataract.     

基于深度学习模型进行屈光不正与玻璃膜疣的相关性分析

目的：采用深度学习模型对彩色眼底图像中的玻璃膜疣进行自动判读，并进一步探讨屈光不正与玻 璃膜疣的相关关系。方法：病例对照研究。选取2017年1─12月在宁波市医疗中心李惠利医院行健 康体检且年龄大于50岁的参与者，共1 035例（2 055眼）的彩色眼底图像，使用DeepSeeNet深度学习 模型对彩色眼底图像进行自动分析判读，按玻璃膜疣大小进行分组。同时随机选择392张（19.1%） 彩色眼底图像采用人工阅片方法对玻璃膜疣大小进行判读，采用Cohen's Kappa检验比较2种判读 方法的一致性。根据电脑验光数据计算等效球镜度（SE），并分为中重度远视（>+3.0 D）、轻度远视 （+0.51～+3.0 D）、正视（-0.5～+0.5 D）、轻度近视（-3.0～-0.51 D）、中重度近视（<-3.0 D）。应用 Logistic回归模型进行屈光不正与玻璃膜疣的相关性分析。结果：深度学习模型对玻璃膜疣大小判读 与人工阅片结果具有高度一致性（κ＝0.67，P<0.001）。在矫正性别、年龄等因素后，SE向正方向增 加与大玻璃膜疣发生风险相关（OR=1.03，95%CI：1.01～1.04，P<0.001）。中高度近视为玻璃膜疣的 保护因素，与正视者相比，中重度近视者发生大玻璃膜疣的风险为0.89（95%CI：0.82～0.97）；相反， 中高度远视为危险因素，与正视者相比其发生大玻璃膜疣的风险为1.20（95%CI：1.03～1.39）。结论： 屈光不正与玻璃膜疣的发生相关。深度学习作为一种新型技术，除了可以增强医师临床诊断的速度 和精准性，同样可以为年龄相关性黄斑变性相关的科研提供线索。     

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

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.