弱视发病机理的综合研究新进展

关于弱视发病机理,多年来人们一直在临床和基础从不同角度进行研究.而初步认识弱视发病实质及变化规律,还是从神经生理及生物学角度所做的大量研究。除形态学、电生理学研究外,近年来人们更倾向于应用药理学、分子生物学及免疫细胞化学等综合技术研究弱视发病机理,在更深层次了解弱视视觉系统变化特性,使得弱视发病机理逐渐明朗化。一视觉系统发育、解剖和弱视的病理生理学研究 Sidman等(1982)提出在生后早期发育中,大脑神经元的生长、迁移和死亡依赖于外部世界环境的影响,因属于上皮组织(外胚层),它有着与机体其它上皮组织相同的特性.Edelman(1988)将发育中的上皮组织分为两型,驱动型和调节型。驱动型为新生的细胞按需要     

弱视发病机理的多学科综合研究进展

本综述并分析了弱视发病机理的神经发育学、解剖学、生理学、药理学、分子生物学及免疫细胞化学研究进展。提示弱视产生的功能变化与视觉通路可塑性变化确有形态学、生理学和神经分子生物学基础。弱视的综合学科研究不可忽视。     

弱视发病机理的多学科综合研究进展

本文综述并分析了弱视发病机理的神经发育学、解剖学、生理学、药理学、分子生物学及免疫细胞化学研究进展。提示弱视产生的功能变化与视觉通路可塑性变化确有形态学、生理学和神经分子生物学基础。弱视的综合学科研究不可忽视。     

弱视儿童脑电功率谱研究

应用脑电功率谱对弱视儿童及正常儿童的大脑枕区视中枢细胞功能活动进行观察测定，两者进行了对比，这一电生理研究证弱视儿童的枕区中枢的脑电总功率比正常儿童减低，并证明斜视性弱视、屈光参差性弱视儿童枕区视中枢的细胞活动受到抑制，并提示各型弱视的发病机理和病变部位并不相同，且一眼弱视，其对侧眼并非为正常眼。     

弱视眼底光学相干断层扫描的研究进展

弱视是由于视觉发育关键期内各种异常的视觉经验导致单眼或双眼最佳矫正远视力低于正常同龄儿童,而眼部无明显器质性病变。目前普遍观点认为,弱视的发病机理主要源于视皮层。近年来,光学相干断层扫描（OCT）作为一种先进的活体成像技术,促进了对视网膜形态结构的大量研究,同时也被应用到弱视的研究领域。陆续有不同的研究人员利用OCT发现弱视患者眼底视网膜、脉络膜等眼部结构存在改变。笔者将对弱视眼底OCT的研究进展做一综述。     

视觉发育与弱视

近30年视觉发育的研究揭示人类和哺乳动物出生时视觉系统都未发育成熟。出生后各种视功能在不同年龄形成和成熟过程中视觉系统有相当大的可塑性,能够根据视觉环境刺激调整和改变与生具有的神经联系。在极敏感的视觉发育阶段,异常的视觉环境可造成视觉功能发育障碍导致弱视。迄今为止对弱视发病机理的大量研究发现,不同类型弱视造成的行为学、生理学、形态学改变在视系统不同层次的机制是不相同的。因而提示目前临床弱视治疗方法有待研究和发展。     

弱视发病的分子生物学机制研究进展

弱视是儿童视觉发育时期常见的眼科疾病之一,其发病机制较为复杂。本文对当前弱视发病机制的研究文献进行了总结,从视觉神经递质及其受体、细胞因子、相关基因和蛋白,以及调节激酶表达角度分析了视觉发育以及弱视发病的分子生物学机制。以期为视觉可塑性、弱视发病机制及治疗研究提供参考依据。     

扩散张量成像技术在弱视发病机制研究中的应用

弱视作为常见的儿童眼病,其发病机制自今仍未完全清楚。近年来神经功能影像学工具和技术不断更新和发展,将其应用于弱视发病机制的研究,发现弱视患者视觉中枢的各项技术检测指标和正常人相比有一定差异,表明这些技术对弱视中枢研究有一定价值。特别是扩散张量成像技术的引入,为弱视发病机制的中枢神经系统假说提供了形态学的证据。     

弱视儿童自发脑电功率谱研究

应用脑电功率谱对弱视儿童及正常儿童（各５０例）大脑枕部视区功能活动进行测定，并对两者进行了比较，结果表明：弱现儿童的视区脑电总功率比正常儿童减低，并表明斜视性弱视，屈光参差性弱视儿童枕区活动受到抑制，提示各型弱视的发病机理和病变部位并不相同，且一眼弱视，其对侧眼并非为正常眼。     

左旋多巴治疗弱视的新进展

随着弱视发病机理的深入研究，有关弱视治疗已经从传统的遮盖疗法中发展出一些新的疗法。1990年有人首次报告单剂量左族多巴可改善弱视，以后有人对主旋多巴治疗弱视进行了系统的药物动力学、安全性、耐受性等基础及临床研究。结果表明0．55mg／kg左旋多巴和25％卡比多巴，每日3次，可以治疗弱视，并且不产生明显的副作用，可望成为弱视治疗的最有价值的疗法，一改弱视治疗二百年不变的传统遮盖疗法。     

Assessing amblyogenic factors in 100 patients with congenital ptosis

AIM: To study the frequency of amblyogenic factors in patients with congenital ptosis. METHODS: In this cross-sectional study, 114 eyes of 100 patients with congenital ptosis more than 1 year old were included. Amblyopia was defined as best-corrected visual acuity (BCVA) less than 10/10 or a difference between the two eyes of at least 2/10. In patients too young to be measured by the linear Snellen E test, fixation behavior was observed. Different types of amblyopia were assessed for each patient as: 1) anisometropic amblyopia: astigmatic anisometropia ≥1 dpt, hyperopic spherical anisometropia ≥1 dpt, myopic spherical anisometropia ≥-3 dpt (with cycloplegia); 2) strabismic amblyopia, and 3) stimulus deprivation amblyopia (SDA). Then the total incidence of amblyopia and each type of it were obtained. Patients with uni- and bi-lateral ptosis were also compared. RESULTS: The incidence of amblyopia in ptotic eyes was 39/114 (34.2 %), and for each specific cause was: refractive amblyopia in 29.8%, SDA in 10.5%, strabismic amblyopia in 4.3%. Amblyopia was more frequent in severe ptosis, 76% in patients with covered optical axes (OA), compared to non-covered OA (22.5%). In unilateral ptosis with covered OA, astigmatic anisometropic amblyopia was more frequent, and in bilateral ptosis with at least one eye covered OA, spherical anisometropic amblyopia was more frequent. In both unilateral and bilateral ptosis, SDA was more common if the OA was covered. CONCLUSION: As refractive anisometropic amblyopia is more prevalent than SDA, paying attention to all causes of amblyopia may be important in preventing amblyopia in a child with a ptotic eye.     

先天性上睑下垂患者100例弱视致病原因的探讨

目的:评估先天性上睑下垂患者的弱视发病情况。方法:在本横断面研究中,包括1岁以上的先天性上睑下垂患者100例(114眼)。最佳矫正视力小于10/10或两眼之间至少相差2/10者定义为弱视。年幼患者不能进行斯内伦视力表检测者,观察其注视情况。不同弱视患者的类型:1)屈光参差性弱视:散光性屈光参差≥1.00D;远视性球镜屈光参差≥1.00D,近视性球镜屈光参差≥-3.00D(睫状肌麻痹);2)斜视性弱视,3)形觉剥夺性弱视(SDA)。观察弱视的总发病率及类型,并对单侧和双侧上睑下垂患者进行比较。结果:弱视的发生率在上睑下垂患者为39/114(34.2%),其具体原因:屈光参差性弱视占29.8%,SDA占10.5%,斜视性弱视4.3%,严重的上睑下垂患者弱视发病率更高,视轴遮盖者(OA)占76%,而视轴未遮盖者只占22%。在视轴遮盖的单侧眼睑下垂患者,散光屈光参差性弱视发生率更高,在双侧眼睑下垂至少1眼视轴遮盖者,球镜屈光参差性弱视发生率更高。无论单侧和双侧上睑下垂,如果有视轴遮盖,则SDA比较多见。结论:由于屈光参差性弱视比SDA发生率更高,关注导致的弱视所有原因对于预防儿童上睑下垂所致的弱视极其重要。     

Astigmatic axis and amblyopia in childhood

PURPOSE: This study is part of a larger project whose aim is to evaluate the relationship between refractive errors and amblyopia. In an earlier study, we showed that there is a substantial increase in the prevalence of amblyopia among children with oblique astigmatism. To further evaluate this relationship, we examined children with astigmatisms of 1 dioptre or more and varying directions of the astigmatic axes. METHODS: Two groups of astigmatic children, with oblique and orthogonal astigmatism, respectively, were selected for the study at 1 year of age via a general health screening programme. The most emmetropic axis was identified in each child and used in the study. Visual acuity (VA) was tested when the children were between 4 and 4.5 years of age. The presence of amblyopia, defined as difference in VA between the eyes of 0.1 log unit or more, and any increase in acuity following occlusion therapy were noted. RESULTS: The angle of the astigmatic axis strongly relates to the risk of developing amblyopia. Axes +/- 15 degrees from the main axes did not affect the risk of amblyopia but oblique astigmatism significantly increased the risk of developing amblyopia (p = 0.0024). CONCLUSIONS: The results accord with earlier findings that oblique astigmatism increases the risk of developing amblyopia.     

斜视性弱视儿童多焦视觉诱发电位的研究

目的:研究斜视性弱视多焦视觉诱发电位特征,探讨弱视发病机制。方法:采用德国Roland公司的RETIscan3.15多焦视觉电生理仪,记录和分析了斜视性弱视儿童80眼,外斜43眼内斜37眼,并与正常对照组儿童60眼作比较。结果:弱视眼N1-P1波振幅密度平均值和P1-N2波振幅平均值较正常组儿童在中央视野有下降,随离心度增加,这种现象呈下降趋势。P1波潜伏期平均值无明显异常。正常组和各斜视性弱视组N1-P1波振幅密度平均值:颞侧<鼻侧,P1波潜伏期平均值:颞侧>鼻侧。结论:斜视性弱视mfVEP中心区损害重于周边区,波形异常程度与弱视程度无关。内斜性弱视波形异常程度大于外斜性弱视。     

77例儿童弱视综合治疗疗效观察

目的 探讨不同性质各类型儿童弱视的治疗方法和疗效.方法 对77例142只眼弱视儿童,分别按年龄、程度、弱视类型予以分类,并采用矫正屈光不正、增视能多媒体训练系统,遮盖疗法等综合弱视治疗.结果 总治愈率为58%,总有效率为89%.屈光不正性弱视总治愈率为60%,高于斜视性弱视治愈率(45%)和屈光参差性弱视总治愈率(59%).年龄越小,程度越轻,治疗效果越好.结论 根据弱视儿童性质及类型,采用戴镜,增视能多媒体训练系统,遮盖疗法等进行综合治疗,疗效确切.     

Prevalence and causes of amblyopia in a population-based study of young adult men in Singapore

PURPOSE: To determine the prevalence and causes of amblyopia in young adult Chinese, Indian, and Malay men in Singapore. DESIGN: A population-based cross-sectional study. METHODS: Best-corrected visual acuities of all Singaporean men born in the years 1978 to 1983 were measured before enlistment into military service. Those with BCVA of 6/12 or worse were examined by an ophthalmologist for the presence of amblyopia and other causes. RESULTS: Of the 122,596 men examined, there were 428 with amblyopia, an overall prevalence of 0.35%. The prevalence was similar among Chinese (0.34%), Malays (0.37%), and Indians (0.41%, P = .52). Anisometropic amblyopia was the most common type of amblyopia and strabismic amblyopia was more common in Indians. There were little racial differences in the prevalence of meridional or form deprivation amblyopia. CONCLUSION: The overall prevalence of amblyopia was low and was similar among the three racial groups in young adult Singaporean males.     

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。     

儿童远视性弱视与屈光状态的关系分析

目的探讨远视性弱视儿童远视度数与弱视、斜视的关系。方法对远视性弱视儿童300例（550眼）使用阿托品散瞳验光,检查结果进行统计学处理。结果远视性弱视儿童的远视度数由低至高依次为外斜视组、无斜视组、内斜视组。球镜度数越高,弱视程度越高,无斜视组中度弱视比轻度弱视球镜度数高,差异有高度显著性,轻度弱视比中度弱视的柱镜度数高,差异有显著性;重度弱视只有1例。内斜视组中度弱视比轻度弱视的球镜度数高,差异有高度显著性;重度弱视球镜度数比中度弱视低,与斜视和注视性质有关;外斜视组中度弱视比轻度弱视球镜度数高,差异有显著性。结论远视性弱视儿童远视度数与弱视程度有一定关系,但重度弱视还与视觉抑制和中心旁注视关系更为紧密;中高度远视是内斜视的主要原因;远视散光是弱视的重要原因。     

Amblyopia screening for first and second-grade children in Jordan

AIM: To share the results of a national screening program for amblyopia in school children in the north of Jordan. METHODS: This is a prospective national screening study for amblyopia. The program rolls first and second-grade children (6 to 7 years old) in the north of Jordan. The eye examination included: best-corrected visual acuity, cover-uncover test, and cycloplegic retinoscopy. Monocular visual acuity was tested using an ETDRS visual acuity chart without correction. Moreover, children were tested with full cycloplegic refraction when the test criteria were met. Unilateral amblyopia was defined as a best-corrected visual acuity difference of 2 or more lines. In comparison, bilateral amblyopia was defined as a best-corrected visual acuity of 20/40 or worse in the best eye. RESULTS: The prevalence of amblyopia for the total sample tested (n=17 203) was 2.78% (n=479). The most common cause of amblyopia was hypermetropia (64.45%), followed by previous ocular surgeries (15.1%), myopia (10.43%), strabismus (9.39%), and congenital cataract (0.63%). CONCLUSION: This is the first and only study, identi?ng modifiable risk factors in Jordanian children with amblyopia. In their first couple of years of elementary education, many Jordanian children are affected by amblyopia and pass unnoticed. A more governmental effort is needed into screening programs to improve vision in the Jordanian population.     

功能磁共振成像在弱视研究中的新进展

近年来功能磁共振成像（FMRI）技术基于血管内血氧浓度的变化,可以无损伤地反映活体大脑功能,在视觉系统的研究中得到了迅速的发展,尤其在弱视的研究中已取得重要成果。FMRI可用来从整体水平研究弱视患者的皮层损害特点,还能通过它观察眼优势柱转移、视觉运动觉能力的缺陷,比较不同类型弱视的脑功能变化,尤其屈光参差性弱视和斜视性弱视。就FMRI在弱视研究中的新进展进行综述。