早产儿视网膜病变视觉电生理研究进展

早产儿视网膜病变（ROP）是指可发生于未成熟儿的以视网膜血管异常增生为特征的视网膜血管疾病,是造成儿童视力损害的主要原因之一。ROP虽以视网膜血管发育异常为主要临床特征,但临床观察及动物实验证实,ROP同样影响视网膜视神经的发育,引起视网膜和视神经功能的异常,出现视网膜电图（ERG）暗视视杆反应、暗视振荡电位、多焦视网膜电图（mfERG）的异常,此外,对患儿屈光系统的发育也产生不同程度的影响。就ROP动物模型及ROP患者视觉电生理的特点及屈光系统的异常发育与病变之间的关系进行综述。     

0～6岁儿童眼病的社区筛查

0～6岁是儿童视觉功能发育的关键时期,此期内许多眼部疾病不仅可导致儿童视力发育异常,甚至可造成视力残疾(低视力和盲).儿童视残的眼疾中先天性遗传性眼病占47.95％,屈光不正、弱视占17.95％,角膜病占10.26％,视神经疾病占6.92％,先天性白内障占3.08％,视网膜病变、青光眼、眼外伤占10.26％,其他占3.58％.一些眼病有明显的外观异常,如先天性眼球震颤,能够被家长发现,或有明确的病史,如眼外伤,使得家长能够及时带孩子就诊看病.但许多眼病的早期眼的外观无明显异常,不容易被家长发现,如早产儿视网膜病变、视网膜母细胞瘤、先天性白内障、先天性青光眼、斜视和弱视等眼病,当出现明显的眼部及视力异常时,可能已经错过了最佳的矫治时间,造成视觉功能发育异常,或形成视力残疾,甚至危及生命.     

学龄前儿童弱视的早期筛查

弱视是一种由视觉敏感期异常视觉经验引起的以神经系统发育异常为主、无眼部器质性病变的疾病。视力检查是儿童弱视筛查与诊断中的重要组成部分,但对于不能言语表达的低龄儿童,视力检查受到限制。而屈光不正和屈光参差是引起弱视的最常见危险因素,近年来,对弱视的早期筛查不断延伸至对弱视相关危险因素的早期筛查,针对屈光状态的筛查方法与技术也在不断更新发展。本文试对视力检查方法和屈光性质筛查方法进行综述。     

呼和浩特市6月～6岁儿童屈光筛查及影响因素分析

目的了解呼和浩特市6月~6岁儿童双眼屈光状态,分析其影响因素,为制定眼卫生防治措施提供科学依据,促进视力发育。方法采用美国伟伦公司的Suresight手持式视力筛选仪,对1466例儿童的双眼进行屈光状态检查,并从性别、年龄、屈光异常情况及其影响因素等方面进行分析,对屈光筛查异常者转眼科进一步诊治。结果 1466例6月~6岁儿童中屈光异常人数503例(1006眼),总异常率为34.31%;男、女童屈光异常比较无统计学意义(χ2=0.2426,P>0.05);屈光异常主要影响因素为年龄与母亲视力异常。结论重视儿童视力发育状况,早期屈光筛查,早期干预,避免错过最佳治疗时期,导致不良后果发生。     

不同类型屈光参差与弱视和立体视的相关研究

目的:观察不同类型不同差值的屈光参差对视力发育和立体视形成的影响,分析屈光参差与单眼弱视、立体视之间的相关因素.方法:收集2013-01/2014-12在我院门诊初诊屈光参差患者326例的临床资料,记录最佳矫正远、近视力,以及矫正后近立体视,分析弱视和立体视异常的比例.结果:随着屈光参差差值的增大,高屈光眼远近矫正视力下降,弱视发生率增高,异常立体视增多,有统计学差异.远视组出现弱视和立体视异常最早且比例最大,有显著统计学差异.结论:屈光参差差值的大小直接影响弱视和立体视异常的比例,远视性屈光参差形成弱视的差值最小,与其高屈光眼调节功能不足,近视力无法正常发育有关.     

知觉学习治疗成人屈光参差性弱视合并斜视一例

弱视是视觉发育敏感期的空间视力损害为特征的一组视力不良综合征,大多跟早期视觉经历异常相关,如双眼失衡(斜视)、成像质量下降(高度屈光不正、屈光参差或散光)、形觉剥夺(先天性白内障)等[1]。多数学者认为8岁以后,即视觉发育敏感期结束后,对患者的治疗很难凑效,因此,大龄弱视患者被归为难治性弱视。成人弱视患者是年龄较大的一类大龄弱视患者,以往的观点认为该类     

屈光手术后视觉质量和光学质量的提高及有效控制

屈光手术已成为目前矫正屈光不正的常见手术方式之一,现代屈光手术的目的不仅是为了简单地提高视力,还追求视觉质量及手术后光学质量的完美和自然。本述评就各类屈光手术后影响视觉质量的原因、夜间视力障碍的危险因素及影响患者手术后满意度因素等予以分析,并提出选择适合的手术方式、改善切削模式及应用现代更新的各种技术是减少术后视觉不良症状、提高术后视觉质量的有效因素。     

弱视与微扫视

弱视是儿童视觉发育过程中常见的空间视觉发育混乱的眼病,是危害青少年儿童视觉发育的眼病之一,常发生在视觉发育尚未成熟的幼儿期。表现为异常形式的视力及双眼视功能,这种不正常的视觉经验可以由儿童时期的斜视、高度屈光不正、屈光参差和形觉剥夺等原因造成。弱视患者的最佳矫正视力低于正常,对比敏感度降低,立体视缺陷甚至缺失,出现拥挤现象。此外,弱视还对眼球运动系统产生影响。近年来对微扫视的研究成为眼科的热点研究问题,通过文献回顾,可以了解微扫视的研究进展以及微扫视技术在弱视方面的应用。     

屈光性调节性内斜视对儿童双眼立体视觉发育的影响

目的 探讨屈光性调节性内斜视对儿童立体视觉发育的影响.方法 通过观察79例屈光性调节性内斜视儿童不同发病年龄、不同戴镜年龄、不同斜视程度、戴镜及治疗前后的立体视功能、及与65名正常儿童立体视功能的比较,分析各种因素对儿童视觉发育的影响.结果 屈光性调节性内斜视儿童的双眼视觉较正常儿童比较明显异常;发病年龄越小,立体视功能越差;戴镜年龄越小,双眼视觉的发育与恢复越好;眼位偏斜程度对双眼视觉的影响差异不显著.结论 屈光性调节性内斜视严重影响儿童双眼视觉的发育:发病年龄越小,戴镜年龄越大对立体视功能影响越大;反之发病年龄越晚,及时佩戴合适的矫正眼镜,立体视功能恢复的就越好.显斜及屈光不正都会严重影响儿童立体视功能的发育.     

弱视与立体视

用随机点立体视觉检查图对150例3.5～20岁的弱视病人进行立体视觉检查。探讨了视力、视力差、发病年龄、屈光因素、融合功能和同时知觉等与立体视觉的关系。用多因素分析的方法对可能影响儿童立体视觉发育的13种因素进行分析,结果表明视力低侧眼的视力和有无斜视对立体影响最大。     

Ophthalmological problems associated with preterm birth

As survival of preterm infants improves, the long-term care of consequent ophthalmic problems is an expanding field. Preterm birth can inflict a host of challenges on the developing ocular system, resulting in the visual manifestations of varied significance and pathological scope. The ophthalmic condition most commonly associated with preterm birth is retinopathy of prematurity, which has the potential to result in devastating vision loss. However, the visual compromise from increased incidence of refractive errors, strabismus, and cerebral vision impairment has significant impact on visual function, which also has influence on other developmental aspects including psychological and educational. In this review, the normal ocular development is discussed, aiming to exemplify the impact of early exteriorisation on one of the more naive organs of prematurity. This is then related to the incidence and visual consequences of many types of deficit, including refractive error, strabismus, and loss of visual function in preterm populations, with comparisons to term infant studies. Often these conditions are linked with causal and resultant factors being impossible to segregate, but the common factor of increased rates of all types of ophthalmic deficits demonstrates that children born prematurely are indeed premature for life.     

Emmetropisation following preterm birth

BACKGROUND/AIMS: Even in the absence of retinopathy of prematurity (ROP), premature birth signals increased risk for abnormal refractive development. The present study examined the relation between clinical risk factors and refractive development among preterm infants without ROP. METHODS: Cycloplegic refraction was measured at birth, term, 6, 12, and 48 months corrected age in a cohort of 59 preterm infants. Detailed perinatal history and cranial ultrasound data were collected. 40 full term (plus or minus 2 weeks) subjects were tested at birth, 6, and 12 months old. RESULTS: Myopia and anisometropia were associated with prematurity (p<0.05). More variation in astigmatic axis was found among preterm infants (p<0.05) and a trend for more astigmatism (p<0.1). Emmetropisation occurred in the preterm infants so that at term age they did not differ from the fullterm group in astigmatism or anisometropia. However, preterm infants remained more myopic (less hyperopic) than the fullterm group at term (p<0.05) and those infants born <1500 g remained more anisometropic than their peers until 6 months (p<0.05). Infants with abnormal cranial ultrasound were at risk for higher hyperopia (p<0.05). Other clinical risk factors were not associated with differences in refractive development. At 4 years of age 19% of the preterm group had clinically significant refractive errors. CONCLUSION: Preterm infants without ROP had high rates of refractive error. The early emmetropisation process differed from that of the fullterm group but neither clinical risk factors nor measures of early refractive error were predictive of refractive outcome at 4 years.     

学龄前早产儿近视的屈光参数研究

目的:研究1~6岁早产儿近视患者屈光参数的变化,探讨早产儿近视发生发展与屈光参数的关系。方法:收集2016-01/2018-12在湖南省儿童医院眼科门诊随诊的1~6岁早产儿近视者158例316眼作为早产儿近视组,选取同期随诊的早产儿非近视者164例328眼作为早产儿非近视组。检测并分析两组受检者角膜曲率(CR)、前房深度(ACD)、玻璃体腔深度(VITR)、眼轴长度(AL)、晶状体厚度(LT)等屈光参数。结果:1~3岁受检者中,早产儿近视组较早产儿非近视组CR陡(44.47±1.14D vs 43.38±1.22D),AL延长(21.89±0.71mm vs 21.24±0.56mm)(均P<0.05),而ACD、VITR及LT值无明显差异(均P>0.05);4~6岁受检者中,早产儿近视组较早产儿非近视组AL延长(22.49±1.32mm vs21.43±0.72mm,P<0.05),而CR、ACD、VITR及AT值无明显差异(均P>0.05)。1~3岁早产儿高度近视患者较低、中度近视患者CR陡、AL长,4~6岁早产儿高度近视患者较低、中度近视患者VITR深、AL长。结论:屈光参数发育不匹配可能是早产儿近视发生的原因之一,其中眼轴长度变化起主要作用,而角膜曲率陡是低龄(≤3岁)早产儿近视发展的重要因素之一。     

早产儿和足月儿屈光不正的分布和临床特点

目的:观察和分析儿童眼科门诊就诊的屈光不正3～7岁患儿,有早产史和足月产史的患儿的屈光不正的特点和差异.方法:屈光不正179例(358眼),分为2组:早产史者51人,足月产者128人.1%阿托品眼膏散瞳进行视网膜带状光剪影验光.结果:足月儿的屈光不正患儿中,以远视多见,占157/256眼(61.3%),对比有早产儿屈光不正的远视发病25/102(24.5%),差异有统计学意义(P<0.05).有早产儿屈光不正中,以散光发病为主,占81/102眼(79.4%),尤以高度散光、混合散光多见,相对与足月儿,其散光发病,高度散光发病和混合散光发病眼数的差异均有显著性(P<0.05).结论:散光,尤其是高度散光、复杂的混合散光是有早产儿童视力低下的重要原因.临床上散光与弱视的形成关系密切相关,因此不能忽略早产儿童视力发育.最早可提前到2岁即可进行屈光筛查.     

The development of visual acuity in normal fullterm and preterm infants

The development of visual acuity during the first year of life was assessed in 91 normal fullterm infants and 36 preterm infants with minimal perinatal complications, using the forced-choice preferential looking technique. Acuity in the preterm infants lagged behind that of the fullterm infants up to the age of 6-8 months if age was calculated from birth, and then reached equal levels. When age was corrected for prematurity, acuities in the two groups were very similar at all ages, but mean preterm acuity was consistently slightly higher than in the fullterm infants. The results suggest that early visual experience of preterm infants in the period up to the expected date of term may lead to a slight acceleration of the development of behavioural visual acuity. This is discussed in relation to electrophysiological studies which report a greater effect of prematurity on acuity development.     

Visual deficits in children born at less than 32 weeks' gestation with and without major ocular pathology and cerebral damage.

AIMS--A study was carried out to compare the visual abilities of prematurely born children with those of matched full term controls. METHODS--The vision of 68 children born at less than 32 weeks' gestation and aged between 5 and 7 1/2 years at the time of testing was compared with that of a control group of children born at full term, and matched for sex and age from due date. RESULTS--The premature children had significantly poorer distance and near visual acuity, contrast sensitivity and stereopsis, and a high incidence of colour vision defects (predominantly tritan type). These differences were associated with the high incidence of ocular pathology experienced by 31 (45%) of the premature children compared with only nine (13%) of the controls. When excluding children with ocular and cerebral pathology, 32 matched pairs of premature and control children remained. The 32 premature children did not differ from their controls in terms of distance and near acuities or stereopsis, but they did have significantly poor contrast sensitivity in both their 'best' and 'worst' eyes. None of the 32 control children had colour vision defects, compared with seven of the matched premature children. CONCLUSION--This adds support to previous speculation that the preterm eye is at risk of subtle visual impairment independent of the occurrence of refractive error, manifest squint, disorders of the fundus and media, and cerebral damage.     

Visual acuity in premature infants

PURPOSE: To measure grating visual acuity in premature infants and compare it with that in full-term infants. METHODS: The visual acuity of 73 premature and 73 full-term infants was tested at 6 months of age by the Teller Acuity Card procedure. All premature infants had undergone indirect funduscopy for the detection of retinopathy of prematurity (ROP). Seven infants had developed ROP. The mean gestational age of the premature infants was 33 +/- 1.4 weeks as compared with 39.9 +/- 0.9 weeks in the full-term infants. The mean birth weights of the 2 groups were 1,906 +/- 412 and 3,244 +/- 420 g, respectively. RESULTS: Impaired binocular visual acuity was found in 53.4% of the premature infants, but in only 11% of the full-term infants (p < 0.0001). Impaired monocular visual acuity was found in 13.7% of the premature infants as compared with 2.7% of the full-term infants. Within the premature infant group, monocular visual acuity was impaired in 42.9% of those with ROP and in 10.6% of those without ROP (p = 0.0497). Pathological refraction was found in 33.3% of the prematures without ROP and in 14.3% of the prematures with ROP. This difference was not statistically significant. Visual acuity of preterm infants was not different from full-term infants when examined at 6 months of postconceptual age. CONCLUSIONS: Both monocular and binocular visual acuities as measured by the Teller Acuity Cards are worse in premature infants than in full-term infants at the same chronological age. Poor visual acuity in premature infants can be attributed mainly to immaturity of the visual system.     

Cortical visual impairment in children

PURPOSE OF REVIEW: Cortical visual impairment is rapidly becoming a leading cause of visual loss in children in developed countries predominately because of the improved survival rates of premature infants over the past decade. RECENT FINDINGS: Most cases of cortical visual impairment arise from hypoxic ischemic injury to watershed areas of the brain. In the preterm infant the watershed areas are in the subcortex around the ventricles, while in the term infant the watershed areas are between the major arteries with injury to the subcortex and cortex. Therefore, preterm and term injury will manifest different ocular and visual system abnormalities as a result of this damage. Cognitive visual dysfunction, a type of cortical visual impairment, may occur in cases of damage to the peristriate cortex (association areas of the brain). The anterior visual pathways may also be damaged in a retrograde, transsynaptic fashion in cases of cortical visual impairment. SUMMARY: Cortical visual impairment is a prevalent cause of visual loss in children. It encompasses a wide range of visual disabilities from no light reception to normal visual acuity with cognitive visual dysfunction.     

Development of grating acuity in infants with Retinopathy of Prematurity

PURPOSE: To evaluate the visual development in infants with stage 1 approximately 3 ROP and compare their visual results with healthy preterm infants. PATIENTS AND METHODS: One hundred forty-four premature infants were recruited and were divided into 3 groups according to the stage of ROP. Randomly selected preterm subjects with no ROP were taken as controls. Ophthalmic examinations started 4 to 7 weeks after birth and were repeated as needed until the retina was fully vascularized or until any ROP that developed had resolved. Grating acuity was measured by acuity cards between 35-45 weeks of corrected age and by PL method at 12, 18 and 24 months of age. RESULTS: Infants with stage 3 ROP had slightly lower visual acuity scores compared to other infants at most of the testing points throughout the 35-45 week period, which did not show statistical significance at any week. Infants with stage 2 and 3 ROP had similar visual acuity values but slightly lower acuity scores than infants with stage I or no ROP at the 12 month follow-up. The differences were not statistically significant. Stage 3 ROP infants had significantly lower acuity scores compared to infants with stage 1-2 or no ROP at the 18 and 24 month follow-up visits (p<0.0001). CONCLUSION: We stress periodic monitoring of early visual acuity in infants with ROP because of the possibility of impaired visual development.     

The effects of preterm birth on visual development

Children born very preterm are at a greater risk of abnormal visual and neurological development when compared to children born at full term. Preterm birth is associated with retinopathy of prematurity (a proliferative retinal vascular disease) and can also affect the development of brain structures associated with post‐retinal processing of visual information. Visual deficits common in children born preterm, such as reduced visual acuity, strabismus, abnormal stereopsis and refractive error, are likely to be detected through childhood vision screening programs, ophthalmological follow‐up or optometric care. However, routine screening may not detect other vision problems, such as reduced visual fields, impaired contrast sensitivity and deficits in cortical visual processing, that may occur in children born preterm. For example, visual functions associated with the dorsal visual processing stream, such as global motion perception and visuomotor integration, may be impaired by preterm birth. These impairments can continue into adolescence and adulthood and may contribute to the difficulties in learning (particularly reading and mathematics), attention, behaviour and cognition that some children born preterm experience. Improvements in understanding the mechanisms by which preterm birth affects vision will inform future screening and interventions for children born preterm.