模拟日光照射对兔眼视网膜形态学的影响

目的 探讨模拟日光照射所致兔眼视网膜光损伤的早期病理改变.方法 20只健康新西兰白兔随机均分为4组(n=5),按正常饲养组、正常饲养 光照组、低照度饲养组、低照度饲养 光照组,分别给予不同饲养环境照度及30 000lux模拟日光照射30min处理,应用光镜、透射电镜对光照后的视网膜进行形态学观察.结果 正常饲养组、低照度饲养组视网膜组织结构清楚,染色均匀,细胞形态规整.正常饲养 光照组节细胞层、内核层及外核层胞质均有空泡样改变,个别线粒体肿胀;外节膜盘结构紊乱.低照度饲养 光照组节细胞层胞质肿胀,大量空泡样改变,内核层细胞胞质肿胀,大量空泡样改变,胞膜破裂;外核层细胞胞质肿胀,大量空泡样改变,细胞稀少,排列紊乱,部分胞膜破坏;线粒体高度肿胀,嵴断裂;外节膜盘组织结构紊乱,板层结构消失,空泡化.结论 30 000lux模拟日光照射30min即可导致兔视网膜光损伤,且低照度 光照组较正常饲养 光照组光损伤严重.     

Gz对兔眼视网膜组织形态学的影响

为观察十Gz对视网膜组织形态学的影响，对暴露于十5Gz60s的家免神网膜组织进行了光镜及电镜观察。结果表明，＋5Gz作用60s对兔眼视网膜组织形态学无明显改变。说明本实验条件不足以使兔眼视网膜组织形态学发生改变。     

γ射线低剂量照射兔眼晶体损伤的实验观察

目的 探讨低剂量电离辐射对晶体的影响,方法用２５和５０ｃＧｙ＾６０Ｃｏγ射线一次照射兔眼后,后期用透射电镜（ＴＥＭ）和裂隙灯显微镜（ＳＬＭ）观察晶体组织及形态学变化。结果 ＴＥＭ观察到２５和５０ｃＧｙ照射后早期均有明显晶体上皮细胞损伤,表现为胞浆内粗面内质网、线粒体和高尔基氏器等膜性结构水肿及空泡变,细胞间和胞浆内明显水肿,大量空泡形成及层状小体增多。５０ｃＧｙ组更明显。ＳＬＭ观察发现两剂量组照射     

实验性兔眼aPVR睫状上皮组织病理及超微结构观察

目的 探讨前部增生性玻璃体视网膜病变睫状上皮组织病理及超微结构改变。为探讨前部增生性玻璃体视网膜病变引起慢性低眼压的机理提供依据。方法 利用培养的同种兔皮肤成纤维细胞制作前部增生性玻璃体视网膜病变引起慢性低眼压的动物模型，于术前及术后不同时间点分别做组织病理及电镜观察。结果 光镜检查发现实验组术后2、4、8周睫状体水肿，术后4周及8周睫状体无色素上皮萎缩、缺失。电镜检查发现实验组术后4周和8周睫状体无色素上皮线粒体明显减少，细胞内空泡。结论 在前部增生性玻璃体视网膜病变病理状态下，睫状膜的增生和收缩引起对睫状上皮的牵拉，造成睫状体无色素上皮萎缩和睫状体水肿，可能是引起慢性低眼压的主要原因。     

海水浸泡弹道伤骨髓肌组织的超微结构改变

目的 观察火器伤合并海水浸泡后肌组织的超微结构改变。方法 以滑膛枪发射质量为0.38g的钢珠,速度为600～800m/s,钢珠击中兔后肢,分别将致伤兔浸泡于海水中30分钟和1小时,对照组不浸泡。于伤后3、6、12、24小时在距伤道0.2～0.5cm(挫伤区）、0.5～1.5cm(震荡区）处取材,固定于2.5%的戊二醛中作电镜观察。结果 浸泡组弹道伤组织超微结构变化与对照组想像相似,以变性坏死为主,如肌原纤维变性、溶解、变散或发生坏死,形成电子密度高的无结构性团块,内质网扩张,线粒体肿胀、空化、髓鞘样变等,且上述改变随浸泡时间延长而加重。引人注目的是弹道伤组织,尤其是震荡区,伤后6小时出现一些形态结构相对正常的线粒体,12小时最为显著,24小时线粒体再度退变,肌原纤维坏死加重。结论 海水浸泡火器伤肌组织损伤程度较单纯火器伤明显加重,浸泡时间越长,损伤程度越重。伤后6～12小时内弹道伤组织线粒体出现代偿性增生改变。     

海水浸泡弹道伤骨骼肌组织的超微结构改变

目的观察火器伤合并海水浸泡后肌组织的超微结构改变.方法以滑膛枪发射质量为0.38g的钢珠,速度为600～800m/s,钢珠击中兔后肢,分别将致伤兔浸泡于海水中30分钟和1小时,对照组不浸泡.于伤后3、6、12、24小时在距伤道0.2～0.5cm(挫伤区)、0.5～1.5cm(震荡区)处取材,固定于2.5%的戊二醛中作电镜观察.结果浸泡组弹道伤组织超微结构变化与对照组相似,以变性坏死为主,如肌原纤维变性、溶解、离散或发生坏死,形成电子密度高的无结构性团块,内质网扩张,线粒体肿胀、空化、髓鞘样变等,且上述改变随浸泡时间延长而加重.引人注目的是弹道伤组织,尤其是震荡区,伤后6小时出现一些形态结构相对正常的线粒体,12小时最为显著,24小时线粒体再度退变,肌原纤维坏死加重.结论海水浸泡火器伤肌组织损伤程度较单纯火器伤明显加重,浸泡时间越长,损伤程度越重.伤后6～12小时内弹道伤组织线粒体出现代偿性增生改变.     

兔眼冲击伤后视网膜损伤的病理学变化

目的 探讨冲击伤导致视网膜损伤的病理学改变特点。方法 采用兔眼局部冲击伤模型,对伤前和伤后各时相点进行常规眼科检查,并取视网 膜组织做常规HE染色光镜检查和环氧树脂618包埋电镜观察。结果 眼部冲击伤后即刻见球结膜充血、水肿,脉络膜出血和玻璃体出血,视网膜损伤重于眼前节损伤,以眼底改变为主,有明显的视网膜血管改变,组织水肿、渗出、出血等改变。结论 眼部气体冲击伤以视网膜损伤最为突出,可导致视功能障碍。     

犬后肢高速枪弹伤后眼组织结构的改变

目的 观察犬后肢高速枪弹伤后眼组织的病理改变,并对其致伤机制进行初步探讨,为临床诊治提供依据。方法 采用第三军医大学野战外科研究所创伤弹道模型,致犬后肢高速枪弹伤。在致伤后２４小时,观察眼组织的病理结构改变。结果 ⑴大体观察发现除犬伤道有不同程度损伤外,外眼、内眼均有损伤。⑵病理发现,角膜水肿,葡萄膜和视网膜血管扩张充血,甚至出现视网膜脱离。电镜下观察,视细胞线粒体空泡变性,葡萄膜血管管壁部分疏松     

猫视网膜脱离后光感受器细胞形态学改变

为观察猫视网膜脱离后光感受器细胞形态学变化 ,2 8只猫分为实验组和对照组 ,利用微穿刺技术将 0 2 5 %Healon注入到视网膜下腔造成视网膜脱离。脱离后 0 5～90天的视网膜加工成组织切片 ,用于光镜和电镜观察。结果显示 ,视网膜脱离 2 4h,光感受器外节出现膨胀和破裂 ,内节和细胞体损害轻微。脱离后 3～ 1 4天 ,大多数内节出现空泡、线粒体肿胀和嵴的断裂。细胞胞体出现内质网膨胀、线粒体退化以及多囊小体形成。脱离后 1～3个月 ,外核层细胞体之间出现大量空泡或腔隙。某些光感受器胞体出现细胞浆膜破裂 ,胞浆物质和小细胞器丢失。这种改变在视网膜高脱离区比浅脱离区更明显 ,并随脱离时间的延长呈渐进性加重。研究表明 ,视网膜脱离能诱发光感受器细胞发生退行性改变 ,其程度与视网膜脱离的高度和时间有关     

多点扫描激光全视网膜光凝治疗增生期糖尿病性视网膜病变疗效观察

目的:探讨单纯使用多点扫描激光全视网膜光凝治疗严重增殖前和增殖期糖尿病性视网膜病变的疗效。方法:增殖性糖尿病视网膜病变患者接受多点扫描激光治疗,光斑强度达白色反应,30 ms,3×3扫描模式,激光治疗范围符合标准PRP范围,有玻璃体积血和膜牵拉区不予激光。激光治疗1个月后荧光血管造影结果中新生血管、玻璃体积血的回退情况,非灌注区的改变,用以评价激光疗效。应用SD-OCT观察视网膜光凝斑情况,了解激光对视网膜的影响。结果:非随机性选择本院治疗的增殖前期糖尿病视网膜病变Ⅲ期患者10只眼,Ⅳ期(不含玻璃体积血)患者10只眼,Ⅳ期(含玻璃体积血)患者10眼Ⅴ～Ⅵ期患者5只眼,激光后接受玻璃体手术15只眼。多点扫描激光术后1个月复查荧光血管造影,新生血管完全消退7只眼,仍存在明显非灌注区缺少激光者8只眼,需要补激光12只眼。激光治疗当天OCT显示色素上皮层、杆锥体细胞层有水肿,1个月显示局限破坏杆锥体细胞层,未达到内核层(双极细胞层)。结论:单纯多点扫描激光无法控制增殖性糖尿病视网膜病变,需要补充单点激光。对已出现玻璃体积血和视网膜牵拉的患者建议单点激光治疗。     

用体视学方法测定兔眼钝挫伤后脉络膜形态学改变

目的运用体视学方法研究兔眼钝挫伤后脉络膜形态学指标的变化,了解兔眼血循环的改变。方法以自由落体击伤试验兔右眼,损伤能量为3.3 J,造成灰兔单眼轻度钝挫伤模型,左眼正常对照。将兔眼眼球进行HE染色观察脉络膜病理学改变,并采用生物体视学中卡瓦列里原理法测定脉络膜的体积（Vc）、脉络膜血管的体积密度（Vv）、脉络膜血管的体积（Vb）。结果伤后脉络膜血管体积、血管的体积密度以及脉络膜血管的体积均较正常眼球相比明显减小。伤眼脉络膜体积为正常对照组的87.04%（P〈0.05）;伤眼脉络膜血管体积密度为正常眼球的87.70%（P〈0.05）;伤眼脉络膜血管体积为正常对照组值的69.94%（P〈0.01）。结论生物体视学中卡瓦列里原理法测定兔眼脉络膜体积和脉络膜血管体积有效可靠,并能量化比较损伤前后脉络膜及其血管形态学的变化。眼球钝挫伤后脉络膜受到明显损害,脉络膜血管体积明显减小,可能导致脉络膜循环血量减少,从而影响钝挫伤后视网膜功能的恢复。     

机械性眼球损伤的CT表现

目的 探讨ＣＴ检查在机械性眼球损伤中的作用。材料与方法 采用ＧＥ Ｓｙｔｅｃ ４０００ｉＣＴ扫描仪对５９例６２只机械性损伤的眼球（挫裂伤４４只,穿孔伤１８只,除外仅有异物者）进行横断面、冠状面扫描,并对ＣＴ图像进行观察、统计。结果 眼球体积的改变、眼球变形、眼球不连续或部分增厚、玻璃体内斑片状密度增高、晶状体密度降低、晶状体脱位或脱出、球内或眶内异物及眶壁或颅面骨骨折是机械性眼球损伤的常见ＣＴ表现     

Magnetic resonance imaging of tissue and vascular layers in the cat retina

PURPOSE: To report the visual resolution of multiple cell and vascular "layers" in the cat retina using MRI. MATERIALS AND METHODS: T2- and diffusion-weighted MRI at 4.7 Tesla was performed. Layer-specific thickness, T2, spin density, apparent diffusion coefficient perpendicular (ADC(perpendicular)) and parallel (ADC(parallel)) to the retinal surface were tabulated. T1-weighted MRI was acquired before and after intravenous administration of Gd-DTPA and subtraction images were obtained. Histology was performed for validation. RESULTS: Three distinct "layers" were observed. The inner strip nearest to the vitreous (exhibiting large T2, ADC, spin density with Gd-DTPA enhancement) overlapped the ganglion cell layer, bipolar cell layer, and the embedded retinal vascular layer. The middle strip (exhibiting small T2, ADC, spin density without Gd-DTPA enhancement) overlapped the photoreceptor cell layer and the inner and outer segments. The outer strip (exhibiting large T2, ADC, spin density with Gd-DTPA enhancement) overlapped the tapetum and choroidal vascular layer. T2, spin density, ADC(perpendicular) and ADC(parallel) of different "layers" were tabulated. The inner strip was slightly thicker than the other two strips. The total thickness, including neural and nonneural retina, was 358 +/- 13 microm (N = 6) by MRI and 319 +/- 77 microm (N = 5) by histology. CONCLUSION: MRI provides a noninvasive tool to study the retina with laminar specificity without depth limitation.     

基质金属蛋白酶-1降解兔眼增殖性玻璃体视网膜病变增殖膜的实验研究

目的：评价基质金属蛋白酶-1（MMP-1）对增殖性玻璃体视网膜病变（PVR）增殖膜的降解作用。方法：健康成年有色家兔30只,用富含血小板血浆（PRP）诱导双眼PVR模型,各组玻璃体腔注入组织型纤溶酶原激活剂（t-PA）,15 min后注入MMP-1,行PVR分级评分,光镜观察视网膜结构。结果：注药后增殖膜发生较明显降解,各时间点PVR级别与对照组相比,差异有统计学意义（P〈0.01）。结论：一定剂量的MMP-1玻璃体腔注射能对实验性PVR的增殖膜产生降解作用。     

白藜芦醇对兔急性高眼压视网膜热休克蛋白70表达的影响

目的观察白藜芦醇（resveratrol,Res）对兔急性高眼压条件下视网膜节细胞（retinal ganglion cells,RGC）热休克蛋白70（Heat shock protein 70,HSP70）表达的影响。方法 将新西兰大白兔随机分成处理组、对照组和正常组。处理组于急性高眼压模型建立前7天,每天给予腹腔注射白藜芦醇30mg/kg（3ml）,第8天经前房灌注升高眼压达90mmHg（1kPa=7.5mmHg）,持续90min,24h后取材;对照组用等剂量的生理盐水代替白藜芦醇腹腔注射,余同处理组;正常组不做上述处理直接取材。观察兔视网膜组织病理学结果,免疫组化检测视网膜节细胞HSP70表达。结果与正常组相比,处理组和对照组表达在视网膜节细胞的HSP70明显增加（P〈0.05）;与对照组相比,处理组HSP70的表达明显增加（P〈0.05）。结论白藜芦醇通过增加兔急性高眼压视网膜神经节细胞HSP70的表达,减轻RGC的损伤,对视网膜具有一定的保护作用。     

烧伤合并海水浸泡后对实验兔肝脏病理形态学的影响

目的 观察兔烧伤合并海水浸泡后,肝组织病理学变化特点,为兔烧伤合并海水浸泡后的早期救治提供依据.方法 新西兰兔20只,制作烧伤动物模型后,随机分为浸泡组(n=10)和对照组(不经海水浸泡组,n=10).光镜和电镜下观察兔烧伤合并海水浸泡后肝组织病理学变化特点,并用HPIAS -1000病理分析系统测量肝细胞.结果 与对照组相比,兔烧伤合并海水浸泡后肝组织结构发生了明显的改变,肝细胞体积明显缩小.结论 兔烧伤合并海水浸泡后重要器官的病理变化有其自身特点,比单纯兔烧伤后病理变化明显加重.     

外层渗出性视网膜病变的影像学特征与病理学对照

目的：分析外层渗出性视网膜病变(又称 Coats 病)的影像学特征,与病理组织学比较,探讨其影像表现的病理基础,提高诊断准确率。方法回顾性分析8例经手术病理证实的 Coats 病的 CT、MRI 和超声征象,荧光素眼底血管造影术(FFA)检查结果及病理资料。8例均行 CT 平扫、常规 MRI 和超声检查。结果8例均累及单侧眼球。CT 表现：8例均表现为玻璃体内密度增高影,密度均匀、边界清楚,视网膜区增厚;5例前房深度变浅。1例玻璃体、晶状体内多发钙化灶。1例患侧眼球体积增大,1例患侧眼球萎缩,6例双侧眼球体积差别不明显;5例晶状体增厚、位置异常。MRI 表现：8例玻璃体内等 T1、等 T2信号6例,短 T1、长 T2信号1例,长 T1、长 T2信号1例;3例患眼视网膜区见线样短 T2信号;5例病变充满玻璃体,3例呈扁平的“V”形贴于视网膜区。超声表现：玻璃体内点状低回声6例;球壁隆起8例;视网膜脱离8例;球壁回声明显增强,提示球壁骨化1例;强回声钙化斑1例。FFA 表现：视网膜毛细血管扩张8例,伴毛细血管无灌注区2例,散在栗状动脉瘤6例,视网膜新生血管1例。病理表现：镜下见视网膜毛细血管扩张伴大量泡沫状巨噬细胞和脂质沉积。结论Coats 病具有典型的影像学征象,总结其 CT、MRI 和超声征象,结合 FFA 表现,与病理学相互对照有助于本病诊断。     

Hydroxychloroquine treatment alters retinal layers and choroid without apparent toxicity in optical coherence tomography

Background To investigate whether single retinal layer, choroidal and peripapillary retinal fiber layer thicknesses were affected in patients under hydroxychloroquine treatment without retinal toxicityMethods Forty-nine patients under hydroxychloroquine treatment (HCQ group) and 39 healthy volunteers, a total of 88 individuals, were included in the study. Patients with HCQ treatment were further divided into two groups as less than 5 years of HCQ use (group 1, 29 patients) and 5 years or more of HCQ use (group 2, 20 patients). All participants underwent full ophthalmologic examination and optical coherence tomography (OCT) imaging as OCT is a recommended tool for screening toxicity by the American Association of Ophthalmology. The automatic segmentation of retinal layers included retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL), retina pigment epithelium (RPE), inner retinal layers (IRL), outer retinal layers (ORL) and total retina thickness (TRT). Choroidal thickness (ChT), choroidal vascularity index and peripapillary RNFL were also measured.Results Both inferior and nasal parafoveal RNFL, temporal parafoveal GCL, and IPL layer thicknesses were decreased, while temporal parafoveal RPE layer thicknesses were increased in hydroxychloroquine users. Subfoveal ChTs were significantly reduced in both groups 1 and 2 compared to the control group(p = 0.042 and p = 0.009, respectively) and temporal ChT thicknesses were statistically decreased in group 2 compared to the control group(p = 0.018), but not for nasal ChT.Conclusions Hydroxychloroquine use may cause parafoveal retinal layer thickness alterations and also subfoveal and parafoveal ChT alterations even without evident retinal toxicity in OCT.     

OCT and OCTA evaluation of vascular and morphological structures in the retina in recovered pediatric patients with COVID-19

BackgroundUsing OCT and OCTA imaging, we aimed to determine whether COVID-19 induces pathological changes in vascular and morphological structures in the pediatric retina.MethodsThe current prospective, cross-sectional, observational clinical study included recovered pediatric patients with COVID-19 evaluated between May 2020 and June 2020. Retinal vascular (radial peripapillary, superficial, and deep capillary plexus vessel densities) and morphological (peripapillary retinal nerve fiber, ganglion cell layer, retinal, and choroidal thickness) in the optic disk and macula regions were quantitively assessed using OCT and OCTA. Data were compared between COVID-19 patients and age-matched controls.ResultsThe COVID-19 group included 32 eyes of 16 patients and the control group included 32 eyes of 16 cases. Fundus and biomicroscopic examinations revealed no signs of pathology in the COVID-19 group. Mean peripapillary retinal nerve fiber, ganglion cell layer, and choroidal thickness values were significantly greater in the COVID-19 group than in the control group (p<0.05). OCTA indicated that mean superficial and deep capillary plexus vessel densities, and choriocapillaris flow area values were significantly lower in the COVID-19 group than in the control group, whereas mean radial peripapillary capillary plexus vessel density values were significantly higher (p<0.05).ConclusionsEven if fundus examination results appear normal in pediatric patients with COVID-19, vascular and morphological changes may be observed in the retina. Further studies with larger numbers of patients are needed to elucidate the clinical significance of vascular and morphological changes in this population.