Lamina cribrosa thickness in children with hyperopic anisometropic amblyopia

AIM：To determine lamina cribrosa thickness（LCT）in the optic nerve head region of the eyes in children with hyperopic anisometropic amblyopia and to compare this thickness with that of fellow eyes,hyperopic nonamblyopia,and age-matched controls.METHODS：Thirty-two patients（12.0±1.8y,mean±standard deviation）with hyperopic anisometropic amblyopia,31 subjects with age-and refractive error-matched hyperopic non-amblyopia（10.7±2.2y）,and 32 age-matched controls（11.2±2.0y）were included in this prospective,crosssectional study.LCT was measured using an enhanced depth-imaging program of a spectral domain optical coherence tomographic instrument in all participants,and the correlation between LCT and axial length was calculated.RESULTS：The mean LCT was 180.9±29.4μm in amblyopic eyes,247.7±19.0μm in fellow eyes,251.6±27.3μm in hyperopic non-amblyopic eyes,and 240.2±15.8μm in control eyes.Lamina cribrosa in amblyopic eyes was significantly thinner than fellow,hyperopic non-amblyopic,and control eyes（P〈0.05）.There was no significant correlation in LCT and axial length between amblyopic（P=0.16）and control（P=0.31）group.CONCLUSION：Lamina cribrosa of eyes with hyperopic anisometropic amblyopia is significantly thinner than that of fellow eyes,hyperopic non-amblyopia,and age-matched controls.The LCT profile in amblyopic eyes is different from that observed in fellow,hyperopic non-amblyopic,and control eyes.

Age related changes of the central lamina cribrosa thickness, depth and prelaminar tissue in healthy Chinese subjects

AIM： To investigate the variation in the central lamina cribrosa thickness（cLCT）, and the central anterior lamina cribrosa surface depth（cALCSD）, as well as the central prelaminar tissue thickness（cPLTT） related to age in healthy Chinese subjects.METHODS： A total of 96 eyes from 96 Chinese healthy subjects were recruited. According to age, the 96 cases were divided into three groups： the young group（YG, 18-39 y）, middle-age group（MG, 40-59 y） and older-age group（OG, 60 y and above）. Lamina cribrosa images were obtained from all participants using radial linear protocol by enhanced depth imaging spectral-domain optical coherence tomography. The cLCT, cALCSD and cPLTT were calculated from the average value of the lamina cribrosa thickness, anterior lamina cribrosa surface depth and prelaminar tissue thickness in the optic nerve head（ONH） centre point and paracentral points（150 μm from the centre point in the horizontal and vertical directions）. RESULTS： For the total subjects, the mean cLCT, c ALCSD and cPLTT were 235.18±41.27, 358.02±93.80 and 182.02±92.11 μm, respectively. No statistically significant differences in cLCT, cALCSD or cPLTT were found between gender and different eyes（P=0.27-0.92）. The cLCT of the OG was the thickest among the three groups, while the c PLTT of the YG was the thickest among the three groups（P〈0.05）. Age was positively correlated with cLCT（r=0.42, P〈0.001）, and negatively correlated with cPLTT（r=-0.24, P=0.02）. No significant correlation was found between the age and cALCSD（r=-0.06, P=0.55）. And no correlation has been found between axial length and cLCT, cALCSD and c PLTT（P=0.11-0.81）.CONCLUSION： The impact of age on the cLCT and the cPLLTT should be taken into account when analysing glaucoma and other diseases related to lamina cribrosa.

Enhanced depth OCT imaging of the lamina cribrosa for 24 hours

The lamina cribrosa thickness（LCT） could be affected by dynamic changes in its structure.Using spectral-domainoptical coherence tomography（SD-OCT）,we have studied the behaviour of the laminar region in 14 young subjects over 24 h.Significant changes in LCT were observed,depending on the time at which the measurement was taken,with the maximum thickness being observed at 7.30 p.m.,and the minimum at 7.30 a.m.This finding could suggests a circadian pattern in the LCT thickness in healthy subjects,which could have implications for the classification,diagnosis and prognosis of both normal and glaucomatous subjects.

Optic nerve compression:the role of the lamina cribrosa and translaminar pressure

AIM： To describe the morphological changes of the lamina cribrosa （LC） in patients with optic nerve compression. METHODS： Cross-sectional study. Twenty eyes with optic nerve compression, affected by Graves＇ ophthalmopathy （GO） were compared with 18 refractive error-matched healthy eyes. The following examinations were performed： best-corrected visual acuity （BCVA）, intraocular pressure, optic nerve echography, visual field, SD-OCT including the retinal nerve fiber layer （RNFL）, ganglion cell complex （GCC）, and LC thickness and extent. RESULTS： A-scan revealed significant differences in the subarachnoid space （SAS） between the affected and control groups. LC thickness and LC area were 233 pm （SD 23） and 0.41 mm2 （SD 0.19）, respectively. Average GCC thickness （P=-0.0005）, LC thickness （P=-0.001）, MD （P=-0.001） and PSD （P=-0.001） differed significantly between the two groups; whereas LC area （P=-0.2） and average RFNL （P=-0.1） did not. CONCLUSION： Optic nerve compression reduces the SAS thereby altering the morphology of LC thickness and causing GCC damage.

Prevalence of focal lamina cribrosa defects in eyes with pachychoroid disease spectrum

AIM:To determine the prevalence of focal lamina cribrosa(LC)defect among patients with pachychoroid disease spectrum(PDS)in the absence of peripapillary retinoschisis.METHODS:This retrospective,cross-sectional study comprised of 180 patients with PDS,including polypoidal choroidal vasculopathy(PCV),central serous chorioretinopathy,and pachychoroidal neovasculopathy.Medical records and optic ner ve head evaluations conducted using spectral-domain optical coherence tomography with enhanced depth imaging were reviewed.As a control group,236 patients who underwent ophthalmologic evaluation for vitreous floaters,without obvious ocular disease,were also included.RESULTS:The mean age of the PDS group,which included 118 male patients(65.6%),was 57.4±11.1 y.There was no significant difference between the two groups in age(P=0.710)or sex(P=0.248).Six patients(3.3%)in the PDS group and none in the control group showed focal LC defect(P=0.318).Among the six patients with focal LC defect in the PDS group,four eyes had PCV,one eye was the fellow eye of a PCV eye,and one eye had pachychoroidal neovasculopathy.CONCLUSION:Focal LC defect can be defected in patients with PDS in the absence of peripapillar y retinoschisis.However,the prevalence of focal LC defect was not different significantly between PDS patients and those who did not have PDS.

A Study on the Structure of Human Optic Nerve Lamina Cribrosa

Purpose:To determine the mechanism of nerve fiber damage in glaucoma by studing the structure of hu-man optic nerve lamina cribrosa(LC)in different regions.Methods:15 human eyes of 10cases were stuided.The specimens were prepared for scanning electron microscopy,and numbers and areas of pores in LC were measured by electron image analysis system.Draw a frequency distribution map with each curve represents the tendency of pores distribution in a particular part.The proportion of the connective tissue in respective quadrant can also be calcu-lated.The specimens were also prepared for histological examination.Results:There are many pores of various magnitude and shapes on the surface of LC.There are significantly more large pores(≥3000μm^2)in the superior and in-ferior than those in the nasal and temporal quadrants,especially in the peripheral regions,In terms of area,the percentages of connective tissue in the nasal and temporal quadrants are the highest.Collageous fibers,various in diameter,are arranged in bundles and tangentially around each pore.Conclusion:In normal persons,the percentage of large pores in the superior and inferior peripheral parts is the highest,the density of the connective tissue is the lowest.So,the force received by unit area of the superior and inferior parts is bigger than that of the nasal and temporal sides.therefore,it is susceptible to the impact of high intraocular pressure at the early stage and causing correspond-ing visual edfect.Our study may suggest the mechanism of optic nerve damage of glaucoma,Eye Science 1995;11:147-154.

Automatic Anterior Lamina Cribrosa Surface Depth Measurement Based on Active Contour and Energy Constraint

The lamina cribrosa is affected by intraocular pressure, which is the major risk of glaucoma. However, the capability to evaluate the lamina cribrosa in vivo has been limited until recently due to poor image quality and the posterior laminar displacement of glaucomatous eyes. In this study, we propose an automatic method to measure the anterior lamina cribrosa surface depth （ALCSD）, including a method for detecting Bruch＇s membrane opening （BMO） based on k-means and region-based active contour. An anterior lamina cribrosa surface segmentation method based on energy constraint is also proposed. In BMO detection, we initialize the Chan-Vese active contour model by using the segmentation map of the k-means cluster. In the segmentation of anterior lamina cribrosa surface, we utilize the energy function in each A-scan to establish a set of candidates. The points in the set that fail to meet the constraints are removed. Finally, we use the B-spline fitting method to obtain the results. The proposed automatic method can model the posterior laminar displacement by measuring the ALCSD. This method achieves a mean error of 45.34 μm in BMO detection. The mean errors of the anterior lamina cribrosa surface are 94.1% within five pixels and 76.1% within three pixels.

Fibrous Structure of Connective Tissue of Normal Human Lamina Cribrosa.

Fibrous components and structural morphology of the connective tissue of the lamina cribrosa obtained from 35 normal human autopsy eyes were examined by histochemical staining, transmission electron microscopic and computer-

急性高眼压发作后眼后节的变化

眼压急进性升高是急性闭角型青光眼的典型表现,也是导致青光眼患者眼部组织损伤,视力下降甚至失明的重要原因。急性闭角型青光眼的短时间内眼压急剧地升高,会对视网膜、脉络膜以及视神经的结构和功能造成特征性的损伤。目前对于青光眼的诊断及病程评估,很大程度上是依赖于高眼压的状态,视神经的变化及视野的损伤,但此时青光眼患者的眼底已经发生了不可逆性的损伤。而眼后节的微结构改变,对于高眼压更加敏感,往往出现在视神经和视野损伤之前,可以更早的提示高眼压对眼部的损伤。通过对眼后节影像学特点的评估,可以从中探索出临床上评估影响青光眼预后的形态学特征,对于青光眼的早期诊断具有重要的临床意义。

高度近视视神经改变与原发性开角型青光眼的相关性研究进展

高度近视(high myopia,HM)作为一种特殊类型的屈光型眼病,不仅会导致进行性、退行性眼底改变,其视神经损伤的患病率也很高。青光眼是全球范围内最常见的一种不可逆致盲性眼病,原发性开角型青光眼(primary open-angle glaucoma,POAG)是最常见的青光眼类型。近年来的研究发现HM与POAG的病理改变存在相似之处。由于HM眼底改变与早期POAG眼底改变容易混淆,HM患者早期发现POAG对延缓或阻止疾病进展很重要。HM患者长期随访不仅要观察黄斑病变,视神经形态与结构改变的观察也不容忽视。

慢性高眼压青光眼食蟹猴巩膜及筛板生物力学特性的变化

目的探讨慢性高眼压(IOP)青光眼食蟹猴巩膜及筛板(LC)各区域生物力学特性的变化。方法选取健康雄性食蟹猴3只6眼,右眼建立慢性高IOP青光眼模型(实验组),左眼为正常对照眼(对照组)。慢性高IOP青光眼模型建模成功后获取双眼眼球并测量眼球外径,在上方、下方、鼻侧、颞侧4个象限获取视盘周围巩膜(ppSCl)组织试件并测量ppSCl厚度,对各象限ppSCl组织进行双轴拉伸、应力松弛和蠕变试验,并比较两组食蟹猴ppSCl组织弹性模量、应力松弛模量和蠕变率。获取含有巩膜的视盘组织试件并对ppSCl和LC组织进行生物纳米压痕试验,比较两组食蟹猴ppSCl和LC组织压缩模量。结果实验组食蟹猴眼球前后径和左右径均大于对照组(均为P<0.05),实验组食蟹猴ppSCl厚度小于对照组(P<0.001)。实验组食蟹猴下方象限ppSCl横向弹性模量大于轴向,上方、下方2个象限ppSCl横向瞬时模量和上方、下方、鼻侧3个象限ppSCl横向平衡模量均大于轴向(均为P<0.05)。实验组食蟹猴上方、鼻侧、颞侧3个象限ppSCl弹性模量,鼻侧、颞侧2个象限ppSCl瞬时模量,颞侧象限ppSCl平衡模量和4个象限ppSCl蠕变率,两个拉伸方向间比较差异均无统计学意义(均为P>0.05);对照组食蟹猴4个象限ppSCl横向弹性模量、瞬时模量和平衡模量均大于轴向(均为P<0.05),横向蠕变率小于轴向(P<0.05)。实验组食蟹猴ppSCl组织两个拉伸方向的弹性模量、瞬时模量和平衡模量均大于对照组(均为P<0.05),蠕变率均小于对照组(均为P<0.05)。实验组食蟹猴ppSCl组织压缩模量大于对照组(P<0.05),LC压缩模量小于对照组(P<0.05)。结论慢性高IOP青光眼改变了食蟹猴ppSCI及LC的生物力学特性,使ppSCl及LC对高IOP缓冲作用下降,导致视神经盘(ONH)对IOP抵抗力降低,最终造成ONH损伤,从生物力学角度提示为患者设定个性化目标IOP的重要性。

视网膜中央静脉阻塞患者筛板厚度及中心凹下脉络膜厚度变化研究

目的评估单侧视网膜中央静脉阻塞(CRVO)患者血管内皮生长因子(抗VEGF)治疗前后双眼筛板厚度(LCT)和黄斑中心凹下脉络膜厚度(SFCT),并与年龄匹配的健康对照组眼进行比较,探讨LCT或SFCT与视力或眼压的关系。方法前瞻性病例对照研究。随机选取2019年6月至2021年6月在安徽省第二人民医院接受治疗的31例单眼CRVO患者(31只眼)作为患病组(根据是否患病设为两个子集,分别为患侧眼组和对侧眼组),将同时期年龄匹配的健康体健者30例(随机选取某一侧眼纳入研究,共30只眼)作为健康组。所有患眼均接受康柏西普注射治疗。采用增强深部成像光相干光层析成像术(EDI-OCT)测量所有纳入者治疗前和治疗后2周LCT及SFCT,并记录患者的年龄、性别、视力及眼压等进行比较。结果治疗前,CRVO患者患侧眼和对侧眼的LCT明显薄于健康眼(均P<0.001),患侧眼和对侧眼的LCT差异无统计学意义(P=0.302);CRVO患者患侧眼的SFCT明显厚于健康眼和对侧眼(均P<0.001),健康眼和对侧眼的SFCT差异无统计学意义(P=0.373)。治疗后2周,CRVO患者患侧眼和对侧眼的LCT明显薄于健康眼(均P<0.001),患侧眼和对侧眼的LCT差异无统计学意义(P=0.936);CRVO患者患侧眼的SFCT明显厚于健康眼和对侧眼(均P<0.001),健康眼和对侧眼的SFCT差异无统计学意义(P=0.745)。此外,在CRVO患者中,LCT与视力及眼压无显著相关性;SFCT与视力呈强负相关性(r=-0.967,P<0.001),与眼压呈弱负相关性(r=-0.375,P=0.034)。结论CRVO患者双眼LCT显著低于健康眼,患眼的SFCT比对侧眼及健康眼明显增厚,薄LCT可能是CRVO发病的一种眼部危险因素。

复方中药青光安对兔慢性高眼压筛板结构及Ⅳ型胶原纤维含量的影响

目的:探讨复方中药青光安混悬液对慢性高眼压兔筛板结构及功能的影响。方法:健康白兔30只,体质量2.5～3.0kg,雌雄不拘。每组6只12眼,分为5组,A为正常空白组、B为模型组、C为青光安组、D为噻吗心安组、E为青光安联合噻吗心安组,建立慢性高眼压模型前、后第1wk内3d测1次眼压,2,5wk各测1次眼压。5wk处死家兔取视乳头及周围组织然后修剪得筛板组织,用免疫组化方法测Ⅳ型胶原纤维平均吸光度值,并在光镜及电镜下观察组织结构的变化。结果:40眼成功造模后当时;1,2,5wk眼压均>22mmHg。造模后5wk时各组眼压进行比较:青光安组眼压与模型组相比无明显差异(P>0.05),与其他治疗组及正常组相比有极显著差异(P<0.01);噻吗心安组与联合组眼压相比无明显差异,并且两组与正常组眼压相比亦无明显差异。造模后5wk正常组Ⅳ型胶原纤维平均吸光度值与联合组相比无显著差异,与其他3组相比有极显著差异(P<0.01);联合组与青光安组、噻吗心安组及模型组相比有极显著差异(P<0.01)。光镜、电镜结果表明,与模型组比较,治疗组巩膜筛板部纤维走向基本有序,无断裂、水肿,神经细胞胞质内线粒体大致正常,其中各组筛板结构病理改变程度由大到小依次为:噻吗心安组、青光安、联合治疗组。结论:青光安混悬液对慢性高眼压通过改善视网膜微循环起到筛板组织保护的作用,青光安联合噻吗心安明确降压后对筛板组织结构保护作用更为明显。

EDI-OCT在视网膜分支静脉阻塞患者筛板厚度测量中的应用

目的分析增强深部成像光学相干断层扫描(enhanced depth imaging optical coherence tomography,EDI-OCT)在测量视网膜分支静脉阻塞(branch retinal vein occlusion,BRVO)患者筛板厚度(lamina cribrosa thickness,LCT)中的应用价值。方法收集2014年9月至2016年3月我院收治的65例单侧BRVO患者的临床资料作为观察组,选取同期来我院体检的40位正常人的单眼健康眼作为对照组,采用EDI-OCT测量两组全周视网膜神经纤维层(retinal nerve fiber layer,RNFL)厚度、LCT、中央角膜厚度、眼轴长度、视盘横径、视盘竖径、屈光度、视野缺损范围等指标的变化。结果两组中央角膜厚度、眼轴长度、视盘横径、视盘竖径、屈光度比较差异均无统计学意义(均为P>0.05);观察组视盘各区域LCT、全周RNFL厚度均低于对照组,差异均有统计学意义(均为P<0.05);观察组视野缺损范围高于对照组(P<0.05)。LCT与BRVO患者全周RNFL厚度呈正相关,与视野缺损呈负相关(P<0.05)。结论 EDI-OCT可作为活体LCT检测的有效手段,青光眼BRVO患者LCT较正常健康人薄,且其LCT与全周RNFL厚度呈正相关,与视野缺损呈负相关。

缺氧、低营养对人眼筛板细胞纤维连接蛋白合成的影响

目的研究筛板间质纤维连接蛋白（ＦＮ）合成与血供的关系。方法在缺氧、低营养条件下对筛板细胞进行体外培养，光镜及电镜下观察其形态变化，采用免疫细胞化学和计算机图像分析对筛板细胞ＦＮ合成行定量分析。结果筛板细胞在缺氧、低营养条件下可发生胞浆内空泡、线粒体异形化、环形样小体等变性改变。缺氧２４ｈ及５％胎牛血清（ＦＣＳ）培养液中，筛板细胞ＦＮ合成量分别为１１．８８２０±３．５６５７、１５．１０２０±２．８９６９ＯＤ，与对照组比较，Ｐ＜０．０５；缺氧４８ｈ及１％ＦＣＳ培养液中，筛板细胞合成ＦＮ量开始减少，与对照组比较仍有不同程度增高。结论缺血可致筛板细胞结构变化和对ＦＮ合成有刺激作用。

足月胎儿巩膜筛板的形态测量学研究

对１５例足月胎儿巩膜筛板的石蜡切片用计算机图像分析系统进行了形态测量学研究，发现足月胎儿巩膜筛板已形成区域性结构差异，即筛板上、下象限较鼻、颞象限筛孔大而结缔组织支撑成分较少，为青光眼性视神经损害发病机理的解释提供了新的理论依据。

颅内压与青光眼及其无创测量技术的研究进展

青光眼是世界上第二位致盲性眼病,第一位不可复性致盲性眼病。尽管眼压增高被认为是青光眼性视神经损害的主要危险因素,但是50%的原发性开角型青光眼患者的日常眼压正常,还有一些患者尽管眼压控制良好,但青光眼性视神经损害仍继续发展。这些现象无法用高眼压理论来解释,青光眼患者视神经损害的发病机制仍待探讨。目前国内外的一些研究表明:(1)视神经周围的生物力学的解剖结构包括眼内压,筛板和球后的脑脊液压力在原发性开角型青光眼的发病机制中发挥重要的作用;(2)正常眼压性青光眼患者的脑脊液压力比正常人低,而跨筛板压力差比正常人高;(3)高眼压症患者的脑脊液压力比正常人群高,而跨筛板压力差和正常人之间没有统计学意义。基于以上研究,本文就颅内压与青光眼性视神经损害之间关系的相关研究进展及临床上可行的无创颅内压测量方法作一综述。

人视神经筛板的发育和结构研究──光镜观察

应用光镜组织学技术研究了人视神经筛板的发育和结构。主要结果如下；胚胎期巩膜筛板发育初步分三个阶段：（1）原始筛板期；（2）巩膜筛板形成期;（3）发育进展期。巩膜筛板是神经胶质与结缔组织相结合而形成，其发育是一个终生过程，而脉络膜筛板始终保留神经外胚叶成分。足月胎儿巩膜筛板梁结缔组织成分与成人差异较大。结缔组织纤维绕筛孔相互交织呈切线状走行。

Parameters of ocular fundus on spectral-domain optical coherence tomography for glaucoma diagnosis

In this review, we summarize the progression of several parameters assessed by spectral-domain optical coherence tomography （SD-OCT） in recent years for the detection of glaucoma. Monitoring the progression of defects in the retinal nerve fiber layer （RNFL） thickness is essential. Imaging and analysis of retinal ganglion cells （RGCs） and inner plexiform layer （IPL）, respectively, have been of great importance. Optic nerve head （ONH） topography obtained from 3D SD-OCT images is another crucial step. Other important assessments involve locating the Bruch＇s membrane opening （BMO）, estimating the optic disc size and rim area, and measuring the lamina cribrosa displacement. Still other parameters found in the past three years for glaucoma diagnosis comprise central retinal artery resistive index, optic disc perfusion in optical coherence tomography angiography （OCTA） study, peripapillary choroidal thickness, and choroidal area in SD-OCT. Recently, several more ocular fundus parameters have been found, and compared with the earlier parameters to judge the accuracy of diagnosis. While a few of these parameters have been widely used in clinical practice, a fair number are still in the experimental stage.

The effect of increased intra-abdominal pressure on orbital subarachnoid space width and intraocular pressure

In accordance with the trans-lamina cribrosa pressure difference theory, decreasing the trans-lamina cribrosa pressure difference can re- lieve glaucomatous optic neuropathy. Increased intracranial pressure can also reduce optic nerve damage in glaucoma patients, and a safe, effective and noninvasive way to achieve this is by increasing the intra-abdominal pressure. The purpose of this study was to observe the changes in orbital subarachnoid space width and intraocular pressure at elevated intra-abdominal pressure. An inflatable abdominal belt was tied to each of 15 healthy volunteers, aged 22-30 years （12 females and 3 males）, at the navel level, without applying pressure to the abdomen, before they laid in the magnetic resonance imaging machine. The baseline orbital subarachnoid space width around the optic nerve was measured by magnetic resonance imaging at 1, 3, 9, and 15 mm behind the globe. The abdominal belt was inflated to increase the pressure to 40 mmHg （1 mmHg = 0.133 kPa）, then the orbital subarachnoid space width was measured every 10 minutes for 2 hours. After removal of the pressure, the measurement was repeated 10 and 20 minutes later. In a separate trial, the intraocular pressure was measured for all the subjects at the same time points, before, during and after elevated intra-abdominal pressure. Results showed that the baseline mean orbital subarachnoid space width was 0.88 ＋ 0.1 mm （range： 0.77-1.05 mm）, 0.77 ＋ 0.11 mm （range： 0.60-0.94 mm）, 0.70 ＋ 0.08 mm （range： 0.62-0.80 ram）, and 0.68 _＋ 0.08 mm （range： 0.57-0.77 mm） at 1, 3, 9, and 15 mm behind the globe, respectively. During the elevated intra-abdominal pressure, the orbital subarachnoid space width increased from the baseline and dilation of the optic nerve sheath was significant at 1, 3 and 9 mm behind the globe. After decompression of the abdominal pressure, the orbital subarachnoid space width normalized and returned to the baseline value. There was no significant difference in the intraocular pressure before, during and after the intra-abdominal pressure elevation. These results verified that the increased intra-abdominal pressure widens the orbital subarachnoid space in this acute trial, but does not alter the intraocular pressure, indicating that intraocular pressure is not affected by rapid increased in- tra-abdominal pressure. This study was registered in the Chinese Clinical Trial Registry （registration number： ChiCTR-ONRC-14004947）.