非接触型角膜内皮显微镜对角膜内皮的观察

目的观察正常人及白内障手术患者角膜内皮细胞。方法应用非接触型角膜内皮显微镜作内皮摄像观察。结果正常人角膜内皮细胞是随年龄增长而发生有规律的改变；白内障手术后周边角膜（切口附近）内皮丢失率大于中央区。结论非接触法检查具有便捷、无痛、非创伤性的特点，并适合内眼术后早期观察，是研究角膜内皮的理想工具。     

微环境对角膜内皮作用机制的研究进展

角膜内皮作为角膜中代谢最为活跃的一层,在维持角膜透明性中发挥重要作用.角膜内皮微环境则是揭示角膜内皮疾病机制和体外培养角膜内皮进而解决角膜内皮移植供体匮乏的关键,其包括了普遍存在的,对细胞有直接作用的生长因子、营养因子、炎性因子及干性因子等各种细胞因子.同时因角膜内皮位置特异性所形成的高氧化环境、眼压等物理应力及相邻组织,如晶状体、角膜后弹力层、房水等与角膜内皮的相互作用也是微环境中的重要因素     

正确选择角膜内皮移植的适应证

角膜内皮移植具有许多独特的优点,有望取代穿透性角膜移植成为治疗角膜内皮失代偿的首选术式.然而,内皮移植也存在术后内皮细胞密度偏低的缺陷,而且,我国的大泡性角膜病变主要见于白内障等眼内手术造成的角膜内皮损伤,病情严重且伴多种眼内异常,使角膜内皮移植面临较大的困难,术后内皮细胞密度下降更明显.根据患者的病情特点,选择合适的术式和适应证是保证手术成功的关键.采用一些改良技术也能减轻内皮细胞的损伤,提高手术成功率.     

角膜内皮移植技术的发展

角膜内皮移植术已成为治疗各种原因引起的角膜内皮功能失代偿的首选术式.角膜内皮移植手术与穿透性角膜移植手术相比,其较好地保持了眼前节的生物学完整性,术后视力恢复更快、更好,大大降低术后并发症等.本文就角膜内皮移植技术的发展过程,主要手术方式,手术的优缺点及术后并发症等进行综述,以期为临床应用提供参考.     

角膜内皮移植术

角膜内皮移植是一种新的治疗角膜内皮病变的手术方法,主要是采用健康的角膜内皮片替代病变内皮层.该方法因为几乎不改变患者的角膜曲率和屈光状态,损伤小,视力恢复快,近年来在临床上逐渐被推广应用,取得较好愈后效果.该方法是角膜移植手术不断精细化和向屈光性手术转化的具体体现.角膜内皮移植术后良好的屈光效果和可能的低排斥率,使其有望成为角膜内皮病变治疗的重要方式.但是,目前内皮移植手术仍然需要完善,改进植入方法以减少脱片率和内皮细胞损失率,利用飞秒激光等进一步提高屈光效果,以及观察术后免疫排斥率是今后眼科学者的研究重点.     

角膜后弹力膜内皮移植术研究进展

角膜后弹力膜内皮移植术由于具有相对较低的移植排斥率以及较好的视力预后等优势,目前已成为部分发达国家治疗角膜内皮失代偿的主流手术方式,但限于手术难度较高,学习曲线较长,中国人前房偏浅,加之国内角膜内皮病变往往合并有其他较复杂的眼部疾病,目前国内尚未普遍开展这一手术。本文就角膜后弹力膜内皮移植术的手术适应证、供体植片制备(...     

角膜内皮移植：机遇与挑战

角膜内皮移植是近年开始流行的一种新型手术方式,本文针对该手术方式的特点、与穿透性角膜移植的差异、角膜内皮移植的手术适应证和并发症、存在的潜在缺陷和可能的解决办法等提出一些建议。     

无缝线深板层角膜内皮移植术的研究进展

角膜内皮失代偿可严重影响视力,以往多采用的穿透性角膜移植手术(PKP)具有术后高度散光、移植片排斥等并发症,严重限制了术后视力的提高.如果能够单纯地进行后弹力层和内皮细胞层的移植,将减少手术操作所带来的受体角膜损伤并能更好地恢复术后视力.近年来,无缝线深板层角膜内皮移植手术的优点已逐渐获得公认;其中深板层角膜内皮细胞移植手术(DLEK)手术难度较大,限制了其在临床的广泛开展.而通过剥除受体角膜的后弹力层和内皮层来制作植床的角膜内皮移植手术即角膜后弹力层剥除内皮细胞移植手术(DSEK)已经取得了较好的手术效果.本文归纳、分析了DSEK的手术方法、效果及并发症等.     

体外重建组织工程人角膜内皮在新西兰兔角膜内皮移植中的应用

目的:验证体外重建组织工程人角膜内皮(TE-HCE)在角膜内皮移植中的作用。方法:以非转染人角膜内皮细胞(HCE细胞)为种子细胞,以去上皮层修饰羊膜为载体支架体外重建的TE-HCE,经CM-DiI标记后对撕除内皮层和后弹力层(DM)的新西兰兔进行了兔穿透性角膜内皮移植。用裂隙灯显微镜观察移植眼角膜的透明度。用荧光显微镜观察种子细胞荧光标记。用茜素红染色和冰冻切片HE染色和扫描电镜观察种子细胞的形态、细胞连接的形成情况、细胞单层的完整性及其与DM结合的紧密程度。用透射电镜方法鉴定种子细胞、DM和角膜的超微结构。结果:TE-HCE可使新西兰兔角膜保持透明39d以上。角膜内皮层移植区的细胞均带有CM-DiI荧光标记。绝大多数种子细胞为六角形,细胞间连接紧密,重建出了完整的角膜内皮层,且内皮层与DM结合紧密。种子细胞重建出了连续的角膜内皮层,种子细胞、DM和角膜的形态结构与正常对照眼的几乎相同。结论:移植后的TE-HCE在种子细胞形态、连续单层状态、细胞连接形成及超微结构上均与对照兔眼的角膜内皮类似,使移植新西兰兔角膜长期保持透明。     

体外培养角膜内皮移植的研究进展

随着角膜内皮细胞体外培养扩增技术不断完善,以及近年后(深)板层角膜内皮移植技术的兴起,以各种载体进行培养角膜内皮细胞进行后板层移植,以代替穿透性角膜移植的研究具有广阔的应用前景。本文就角膜内皮细胞的培养、移植载体的选择和移植技术的发展加以综述,并对目前仍需解决的问题及其前景进行展望。     

DCD角膜移植术后角膜内皮细胞与排斥反应的相关性分析

目的：探讨心脏死亡供体器官捐献(donation after cardiac death,DCD)来源角膜植片术后排斥反应与角膜内皮细胞的相关性。

方法：用角膜内皮显微镜对心脏死亡供体来源角膜植片行穿透性角膜移植术后发生排斥反应的28例28眼角膜植片分别于术后<1、2～3、4～6、7～12mo行角膜内皮镜检查。

结果： 28例患者术后<1、2～3、4～6、7～12mo的角膜内皮细胞变异系数分别为38.23%、49.56%、57.18%、65.04%; 角膜内皮细胞密度分别为2071.15±311.47、1771.33±348.18、1626.59±353.92、1553.14±307.31个/mm²; 角膜内皮细胞变异系数与排斥反应呈正相关关系(r=0.95,P<0.05); 术后角膜内皮细胞密度与排斥反应呈负相关关系(r=-0.93,P<0.05)。

结论：DCD穿透性角膜移植术后发生排斥反应时有角膜内皮细胞变异系数逐步增高,角膜内皮细胞密度逐步降低的趋势; 角膜内皮细胞变异系数、角膜内皮细胞密度可作为早期检测术后排斥反应的指标。     

后弹力层撕除角膜内皮移植术研究现状

后弹力层撕除角膜内皮移植术对角膜表面形态和屈光影响小,视力恢复好,主要治疗各种原因导致的角膜内皮失代偿,如:Fuchs角膜内皮营养不良、大泡性角膜病变、虹膜-角膜内皮综合征或穿透性角膜移植失败。本文就后弹力层撕除角膜内皮移植术技术改进和临床结果的新进展作一综述     

Combined endothelial keratoplasty and clear lens extraction for corneal decompensation in irido-corneal endothelial syndrome

A 38-year-old woman presented with corneal decompensation in left eye secondary to irido-corneal endothelial (ICE) syndrome. She underwent simultaneous Descemet''s stripping endothelial keratoplasty (DSEK) and clear lens extraction with posterior chamber intraocular lens implantation. The surgery was accomplished comfortably without rupture of peripheral anterior synechiae (PAS). 5 weeks postoperatively, the graft was attached, the cornea was clear and best-corrected visual acuity improved from 20/400 to 20/30. DSEK combined with clear lens extraction appears to be an effective measure to treat corneal decompensation in patients with ICE syndrome. Associated lens extraction in such cases increases the working space in anterior chamber for DSEK, which minimizes the intra-operative graft manipulation. This also avoids a future difficult cataract surgery in the presence of PAS and an endothelial graft, which may increase the chances of graft survival.     

Corneal endothelial dysfunction: Evolving understanding and treatment options

The cornea is exquisitely designed to protect the eye while transmitting and focusing incoming light. Precise control of corneal hydration by the endothelial cell layer that lines the inner surface of the cornea is required for optimal transparency, and endothelial dysfunction or damage can result in corneal edema and visual impairment. Advances in corneal transplantation now allow selective replacement of dysfunctional corneal endothelium, providing rapid visual rehabilitation. A series of technique improvements have minimized complications and various adaptations allow use even in eyes with complicated anatomy. While selective endothelial keratoplasty sets a very high standard for safety and efficacy, a shortage of donor corneas in many parts of the world restricts access, prompting a search for alternatives. Clinical trials are underway to evaluate the potential for self-recovery after removal of dysfunctional central endothelium in patients with healthy peripheral endothelium. Various approaches to using cultured human corneal endothelial cells are also in clinical trials; these aim to multiply cells from a single donor cornea for use in potentially hundreds of patients. Pre-clinical studies are underway with induced pluripotent stem cells, endothelial stem cell regeneration, gene therapy, anti-sense oligonucleotides, and various biologic/pharmacologic approaches designed to treat, prevent, or retard corneal endothelial dysfunction. The availability of more therapeutic options will hopefully expand access around the world while also allowing treatment to be more precisely tailored to each individual patient.     

Surgical strategies to improve visual outcomes in corneal transplantation

The recent years have brought about a sea change in the field of corneal transplantation with penetrating keratoplasty being phased to newer lamellar keratoplasty techniques for a variety of corneal pathology. Improved and innovative surgical techniques have allowed selective replacement of diseased host corneal layers with pre-prepared healthy donor corneal lamellae for anterior corneal disorders such as keratoconus and posterior corneal disorders such as Fuch''s corneal endothelial dystrophy. The results of lamellar techniques are encouraging, with rapid visual rehabilitation and vastly reduced risk of immune-mediated transplant rejection. The techniques of deep anterior lamellar keratoplasty and Descemet''s stripping endothelial keratoplasty (DSAEK) continue to evolve with advent of femtosecond lasers and newer concepts such as pre-conditioned donor corneas for Microthin DSAEK and Descemet''s membrane keratoplasty. This review describes the current developments in lamellar keratoplasty, including the futuristic approach using cell therapy to restore vision in corneal blindness.     

A review of the evidence for in vivo corneal endothelial regeneration

Human corneal endothelium has long been thought to be a nonmitotic cell layer with no endogenous reparative potential. Pathologies that damage endothelial function result in corneal decompensation and, if untreated, blindness. The mainstay of treatment involves partial or complete corneal replacement, amounting to 40% of all corneal transplants performed worldwide. We summarize the case reports describing complications postoperatively in the form of (sub)total graft detachment and those resulting in postoperative bare stroma. Complications during cataract and glaucoma surgeries leading to an uncovered posterior cornea are also included. We discuss the newer treatment strategies that are alternatives for current Descemet membrane endothelial keratoplasty and Descemet stripping automated endothelial keratoplasty, including partial grafts and stripping of the diseased cell layer. In more than half of the cases reviewed, corneal transparency returned despite incomplete or no corneal endothelial cell transplantation. We question the existing paradigm concerning corneal endothelial wound healing in vivo. The data support further clinical study to determine the safety of simple descemethorexis in central endothelial pathologies, such as Fuchs endothelial corneal dystrophy, where presence of healthy peripheral cells may allow successful corneal recompensation without the need for donor cells.     

深板层角膜内皮层移植治疗角膜内皮损伤的实验研究

目的:探讨深板层角膜内皮层移植在兔角膜内皮损伤模型的应用效果。方法:选择新西兰白兔24只,制作兔角膜内皮损伤模型第2d随机分为两组:实验组进行深板层角膜内皮层移植术组,对照组不予处理。分别于术后1,2,3,7,14d;1mo观察眼压、前房反应、并发症情况,术后1mo每组处死12只兔子,摘除眼球,12眼(两组各6眼)作病理切片检查,HE染色观察炎症细胞情况;另12眼(两组各6眼)用α-SMAWholemount染色法观察兔角膜内皮细胞瘢痕和肌成纤维细胞情况并进行细胞计数。结果:实验组角膜术后一直维持透明,对照组在术后5d明显变混浊,眼压、前房反应和并发症在两组间差异无显著性(P>0.05)。术后1mo两组实验兔在单位面积(500μm2)肌成纤维细胞数和炎症细胞数均有显著性差异(t=5.716,6.991;P<0.05)。结论:深板层角膜内皮层移植应用于兔角膜内皮损伤模型中炎症反应小,前房反应轻,能保持角膜透明,且并发症少。     

人脐静脉内皮细胞移植治疗角膜内皮功能衰竭的动物实验研究

目的：探讨异种脱细胞角膜基质为载体培养人脐静脉内皮细胞（HUVEC）进行后板层角膜移植（PLEK）治疗角膜内皮衰竭的可行性。方法：新西兰白兔30只,随机分为3组,实验组、基质组和对照组,每组10只,术中去除角膜内皮细胞,建立角膜内皮衰竭动物模型,实验组和基质组行后板层角膜移植术,对照组仅去除角膜后板层组织,不进行移植。术后观察3mo,对三组角膜的水肿混浊程度和中央角膜厚度进行统计学分析。结果：术后7d,实验组角膜水肿程度较基质组和对照组明显减轻,透明度增加。术后3mo时,实验组内皮细胞密度为2 026.4±129.3个/mm2,中央角膜厚度平均为505.2±25.4μm,基质组中央角膜厚度平均为1 535.6±114.5μm,而对照组为1 493.5±70.2μm。结论：实验以异种脱细胞角膜基质为载体培养人脐静脉内皮细胞,行后板层角膜移植术,治疗角膜内皮衰竭取得了初步成功。移植的人脐静脉内皮细胞能够在活体上成活,并具有一定的角膜内皮细胞的生物学功能,维持角膜透明,为临床上治疗角膜内皮疾病提供了新的思路和方法。     

角膜内皮细胞移植

角膜内皮细胞在体外培养的条件下可以在同种异体或异种角膜后弹力层上成功生长,培养的上皮细胞的生长情况及特性与供体年龄、内皮细胞来源部位、载体材料、培养条件、以及是否应用生长因子有密切关系。人角膜内皮细胞培养的成功,以及在非人类的灵长目动物眼上的成功移植,为内皮移植技术的治疗作用提供了实验基础。培养传代的角膜内皮细胞移植到活体上后具有正常内皮细胞的功能,可以作为穿透性角膜移植的替代方法之一加以选择。