共查询到19条相似文献,搜索用时 187 毫秒
1.
近年的一些研究表明,近视患者表现出更显著的暂时性近视反应,其中迟发型近视的暂时性近视反应消退时程延长;进展型近视则表现出比其他近视更显著的暂时性近视反应幅度.研究推测,暂时性近视通过反复累积,增加视网膜离焦,进而引起眼轴增长,发生永久近视.目前,近距离工作后的暂时性近视被认为是近距离工作诱导近视进展的一个可能原因.本文综述了暂时性近视的概念、测量方法,近年来对于暂时性近视测量的一些结果和暂时性近视导致近视进展可能的机制. 相似文献
2.
目的 观察冷色亮光照明下持续阅读对青少年调节功能的影响 方法 自身对照实验研究.18名年龄为(11.2±2.2)岁的青少年在1000 Ix光照度、6500 K色温的照明条件下完成40 min阅读任务,检测阅读前后的调节刺激反应曲线、调节误差和近距离工作相关性暂时性近视结果持续阅读后平均调节误差率(调节误差/调节刺激)显著减小(P<0.05)阅读后呈现的近距离工作相关性暂时性近视幅度为(0.29±0.24)D,时间指数为11.23±18.58.调节刺激反应曲线的斜率和截距,及3D调节刺激时的调节反应在阅读前后差异没有统计学意义 结论 冷色温与高照度搭配的照明条件既可增加阅读时调节反应的准确性,持续阅读后也不会引起显著的近距离工作相关性暂时性近视、或可降低近距离阅读时的视网膜离焦量,减少近视进展机率. 相似文献
3.
林瑶瑶 《中华实验眼科杂志》2021,(6):563-567
青少年近视已成为我国严重的公共卫生问题,呈现出高发病率、低龄化的特点。近视被认为是遗传因素和环境因素共同作用的一类疾病。近年来,环境因素中的近距离工作已成为近视发生和发展危险因素的研究热点,但近距离工作与近视发生和发展之间的关系仍存在争议。本文对近距离工作的内容、近距离工作总时长、近距离工作强度与近视发生和发展的相关流... 相似文献
4.
5.
背景近距离工作时,视网膜的成像质量受调节、瞳孔和像差的共同影响;而近距离工作时视网膜成像的清晰度又被认为是青少年近视发生发展的可能诱因。因此,研究近视及正视青少年在阅读状态下的眼动参数和像差的差异性显得尤为重要。目的研究有初发性近视和进展性近视的青少年在阅读状态下的调节反应、瞳孔直径和像差的差异,从视网膜离焦诱导近视和像差诱导近视这两个假说探讨调节反应和像差与近视发生发展的相关机制。方法57例年龄12~16岁青少年受试者分为正视组16眼、初发性近视组20眼和进展性近视组21眼。嘱受试者阅读左眼前25effl处电脑显示屏上由快速序列视觉呈现方式软件所呈现的一篇中文短文,用SEIKO—WV500型自动验光仪测量调节反应,实时录像记录瞳孔直径,并用WASCA波前像差仪测量像差,对3组间的结果进行比较。结果各组受试者的调节反应和像差的个体差异均较大,在4D的调节刺激下,初发性近视组和进展性近视组的调节滞后值为(1.72±0.53)D,(1.74±0.44)D,高于正视组的(0.96±0.55)D,差异有统计学意义(t=4.25、t=4.47,P〈0.01)。初发性近视组和进展性近视组的调节滞后差异无统计学意义(t=0.18,P〉0.05)。调节刺激在0~4D时,所有受试者的瞳孔直径、全眼像差、高阶像差、球差和彗差均随着调节力的增加而显著减小(P〈0.01),但在同一调节刺激下,不同屈光组之间受试者的瞳孔直径、全眼像差、高阶像差、球差和彗差的差异均无统计学意义(P〉0.05)。结论初发性近视和近视进展过程中在近距离阅读状态下存在较高的调节滞后,近距离阅读状态下对离焦的低模糊敏感性、较高的调节滞后及远视性离焦可能是近视发生、发展的促进因素。 相似文献
6.
目的 分析不同的屈光度组在持续的近距离工作中调节反应的波动,探讨近视者是否对模糊像有较高的感知阈值;分析持续高水平的调节反应可能是导致近视进展的诱因.方法 41位受试者分为3组,正视组14人,稳定性近视组13人,进展性近视组14人,运用开视野式红外验光仪测量受试者的基础调节反应,并在持续1 h规范近距离工作中,每30 s作调节反应的连续测量.记录个体的基础调节反应值和近距离工作中的调节反应波动曲线,比较不同屈光度组在持续近距离工作中的调节反应波动量.结果 不同屈光度组的调节反应在近距离工作前差异无统计学意义(P>0.05),不同屈光度组在持续近距离工作中的调节反应曲线均呈现出上升,平稳然后再下降的趋势,而进展性近视组在近距离工作的后阶段不能迅速回复到基准值,而是维持在较高的水平.正视组的调节反应对基准值的偏离为(0.0826±0.2410)D,近视稳定组和近视进展组在近距离工作中的调节反应对基准值的偏离分别为(0.1905±0.3619)D和(0.1336±0.3030)D.各组之间的偏离在统计学上无显著的差异,但稳定性近视和进展性近视组的调节反应对基准值的偏离有高于正视组的趋势.有8位受试者在持续近距离工作中出现了调节超前现象,其中近视者占了7位.结论 在持续近距离工作中,调节反应呈现出震荡波动,这在一定程度上能反应感知性焦深或模糊阈值的大小.近视者需要作出更大的波动来引导调节反应跨越其增大的焦深.(中华眼科杂志,2009,45:50-55) 相似文献
7.
目的研究正视者、早发性近视者和迟发性近视者在近距离工作后的张力性调节的适应现象。比较不同屈光度组的的位移现象差异。方法SEIKO—WV500检测受试者在近距离工作前和近距离工作10分钟后的张力性调节,并持续测量工作后的张力性调节90秒。结果大多数个体在近距离工作后的瞬间,张力性调节有上升趋势,迟发性近视组的张力性调节位移量高于早发性近视组和正视组。张力性调节的适应随着时间的推移逐渐向基线水平恢复,大部分个体在60秒内恢复至基线水平。结论迟发性近视在近距离工作后张力性调节有较大的正位移,迟发性近视组的张力性调节的回退可能是副交感运动的衰减所致。 相似文献
8.
9.
近视的患病率逐年增长,已经成为一个备受关注的公共健康问题。近视尤其是高度近视,可能引起一系列眼部并发症,进而导致患眼严重的视觉丧失。调节力减弱、视网膜离焦或形觉剥夺等导致的视网膜成像不清使眼轴代偿生长,这是近视发生发展的重要机制。本文对调节功能、周边视网膜远视性离焦及形觉剥夺在近视发生发展中的作用进行综述。 相似文献
10.
11.
12.
Thermometry of 40 eyes before and after visual work at near with different correction of ametropia and tonography of 20 eyes with progressive myopia and 20 eyes with stationary myopia conducted before and after 15-minute reading load under full correction have revealed that visual work at near is accompanied by working hyperemia of ciliary body (rise of temperature in the anterior segment of the eye ball) and hyperproduction of intraocular fluid. In eyes with stationary myopia, hyperproduction is fully compensated by improvement of aqueous outflow from the eye. In eyes with progressive myopia, ophthalmic hypertension takes place because of insufficient improvement of the outflow facility coefficient. It is likely that working hyperemia of the ciliary body and hyperproduction of intraocular fluid under conditions of visual work at near can be realized as a factor of myopization of the human eye in case of a certain predisposition: in eyes with a not fully formed angle of the anterior chamber or in eyes with anomalous development of the angle. 相似文献
13.
Seang‐Mei Saw 《Clinical & experimental optometry》2003,86(5):289-294
The prevalence rates of myopia are higher in urban Asian cities such as Hong Kong and Singapore. One observation over the past few decades is that the prevalence rates of myopia have been rising and there is an epidemic of myopia in Asia. The age‐old question of the roles of nature and nurture in this process remains unanswered. The strongest evidence for an environmental link to myopia is near work activity. Childhood exposure to night lighting has also been explored in different studies but the results have been mixed. Twin studies, segregation analysis and association studies have demonstrated that hereditary factors play an important role in myopia development. The exact nature and interplay of genetic and environmental factors is not known and data suggest that environmental factors may interact with genetic factors to increase the risks of developing myopia. Future research is needed to identify specific modifiable lifestyle factors and genetic markers for myopia. This will enable preventive measures such as health education to be instituted. 相似文献
14.
目的:研究近视人群在不同注视眼位下的眼压变化。方法:系列病例研究。选择2019 年12 月至 2020年1月在校的暨南大学单纯性近视大学生为研究对象。根据等效球镜度(SE)分为低度、中度、 高度近视组。对所有研究对象进行眼部检查,获取眼轴长度(AL)、中央前房深度(ACD)、中央角膜 厚度(CCT)及角膜曲率(K1、K2)等参数。采用iCare回弹式眼压计测量双眼原在位放松状态下的基 础眼压(IOPP)及分别注视9个不同眼位(集合、上、下、左、右、左上、左下、右上、右下)5 min后的 眼压,每个注视眼位间隔休息5 min。采用独立样本t检验、单因素方差分析及相关性检验对数据进 行分析。结果:最终纳入研究对象60例(60眼),其中低、中、高度近视组分别为21、28、11眼。左 右眼IOPP差异无统计学意义(t=0.835,P=0.406),以右眼为研究眼。3组间SE、AL差异有统计学意 义(F=139.789,P<0.001;F=21.917,P<0.001),而组间IOPP、ACD、CCT、K1、K2差异均无统计学 意义。近视眼人群向9个不同眼位注视5 min后的眼压值与IOPP[(13.80±3.92)mmHg]差异无统计学 意义。3组的IOPP、下方眼位眼压(IOPD)与SE均无相关性,IOPP与AL均无相关性。低、中度近视组 的集合眼位眼压(IOPC)与SE之间无相关性,高度近视组的IOPC与SE呈正相关(r=0.713,P=0.014)。 结论:不同注视眼位下的眼压与IOPP之间无差异,IOPP与SE之间无明显相关性,但高度近视者更应 科学合理用眼,避免长时间近距离用眼。 相似文献
15.
Sulfonamide medications can cause an idiosyncratic reaction, resulting in acute transient myopia and acute angle-closure glaucoma. The risk of an adverse reaction to a sulfonamide is approximately 3%, and the exact mechanism of the myopia and angle-closure glaucoma remains controversial. Typical clinical presentation includes bilateral involvement with blurring of vision that generally occurs over minutes to hours, nausea or vomiting, red eye, and headache. Examination may show conjunctival injection, corneal edema, anterior chamber inflammation, and flat or shallow anterior chamber. Diagnosis is based on clinical suspicion, although an ultrasound biomicroscopy may be helpful in diagnosing swelling of the ciliary body. Topiramate, a sulfa derivative, is used for the treatment of migraines or seizures. The side effects include acute myopia and angle-closure glaucoma. Treatment of this condition is primarily supportive along with discontinuation of the medication; topical miotics and peripheral iridectomy are not helpful. If intraocular pressure remains uncontrolled, additional therapies, such as topical intraocular pressure-lowering medications, high-dose steroids, and trabeculectomy, may need to be considered. 相似文献
16.
Charles W McMonnies MSc 《Clinical & experimental optometry》2014,97(2):116-124
An examination of how intraocular pressure distending forces on the posterior sclera are an important mechanism in the development and progression of axial myopia has been made. Papers were selected from the results of PubMed (143) and Science Direct (1,398) searches using the key word combinations of ‘axial myopia’ and ‘intraocular pressure’. The main points include that the sclera is exposed to distending forces at all levels of physiological and pathological intraocular pressure. Reversible axial elongation is a common physiological response to elevated intraocular pressure in healthy eyes but more so in myopic eyes. Key variables, which appear to determine pathological (non‐reversible) axial elongation include the thickness, rigidity and viscoelasticity of the posterior sclera and the associated increased susceptibility of it to distending forces. Intraocular pressure appears likely to have a greater role when it is above normal. Intraocular pressure elevations, which are not detected by clinical or experimental tonometry, may be significant contributors to axial elongation. Axial elongation can be pathological in myopic or myopically predisposed eyes, when elongation is not reversible. Axial elongation has also been associated with retinal defocus in both animals and humans, when thinning due to loss of scleral collagen and/or ground substance, which is driven by the retina, appears likely to be associated with increased scleral susceptibility to intraocular pressure. As myopia progresses, signs of retinal and choroidal stretching are an increasingly apparent consequence of the balloon‐like expansion of the posterior sclera in response to intraocular pressure. Avoidance or moderation of activities which are known to elevate intraocular pressure may improve the prognosis for patients with genetic and/or environmental predisposition to myopic progression and may be an important consideration, even when other myopic control measures are being used. 相似文献
17.
目的 探讨高度近视黄斑裂孔性视网膜脱离合并脉络膜脱离的相关危险因素,总结其临床特点及治疗方法.方法 连续收集合并脉络膜脱离的高度近视黄斑裂孔性视网膜脱离的病例10例(A组),并以同一时期不伴脉络膜脱离的高度近视黄斑裂孔性视网膜脱离病例12例为对照(B组),对比两组发病年龄、病程、术前屈光度、眼轴、眼压、视网膜脱离范围以及术后视网膜复位、视功能恢复等情况.结果 A组发病年龄大、近视度数高、眼压低、视网膜脱离范围大,与B组相比差异有统计学意义(P<0.05),其中眼压差异显著(P<0.01);两组的一次玻璃体切割手术视网膜复位率相近,A组为80%,B组为83%,但A组术后视力≥0.02的比例低(P=0.048).结论 高度近视黄斑裂孑L性视网膜脱离一旦合并脉络膜脱离常伴有年龄大、病程长、近视度数高、视网膜脱离广泛和显著低眼压等特点.适时采用玻璃体切割合并硅油填充术可达到与不合并脉络膜脱离组相近的视网膜复位率,但视力预后仍较差. 相似文献
18.
Myopia is a health issue that has attracted global attention due to its high prevalence and vision-threatening complications. It is well known that the onset and progression of myopia are related to both genetic and environmental factors: more than 450 common genetic loci have been found to be associated with myopia, while near work and outdoor time are the main environmental risk factors. As for many complex traits, gene–environment interactions are implicated in myopia development. To date, several genetic loci have been found to interact with near work or educational level. Gene–environment interaction research on myopia could yield models that provide more accurate risk predictions, thus improving targeted treatments and preventive strategies. Additionally, such investigations might have the potential to reveal novel genetic information. In this review, we summarised the findings in this field and proposed some topics for future investigations. 相似文献
19.
Dharani Ramamurthy Sharon Yu Lin Chua Seang‐Mei Saw 《Clinical & experimental optometry》2015,98(6):497-506
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. 相似文献