Ⅱ型糖尿病性视网膜病变患者角膜内皮细胞结构变化的研究

目的：探讨非胰岛素依赖型糖尿病合并视网膜病变后其内皮细胞密度及形态学的变化。方法：选择40例糖尿病视网膜病变患者，分为增殖型视网膜病变组和非增殖型视网膜病变组。观察其内皮细胞密度及形态学变化，并与正常对照组进行比较，统计学分析。结果：糖尿病增殖型视网膜病变患者角膜内皮细胞密度及六边形细胞百分比明显降低，变异系数增加，糖尿病非增殖型视网膜病变患者角膜内皮细胞密度降低，形态学与下对照组比较差异无显著性。结论：非胰岛素依赖型糖尿病视网膜病变患者其角膜内皮细胞结构有异常变化。     

糖尿病患者角膜内皮细胞形态学和角膜厚度研究分析

目的：通过对糖尿病患者进行角膜内皮细胞形态学定量分析,评估糖尿病对角膜内皮细胞的影响。
　　方法：应用全自动角膜内皮细胞分析仪对299例360眼进行角膜厚度及内皮细胞形态检测。正常对照组148例175眼,糖尿病患者151例185眼,其中非增殖期组患者92例110眼,增殖期组59例75眼。比较各组患者的中央角膜内皮细胞平均密度、六边形细胞比例、变异系数及角膜厚度,并进行统计学分析。
　　结果：糖尿病组与正常组角膜相比,角膜内皮细胞变异系数及中央角膜厚度增加,中央角膜平均细胞密度以及六边形细胞比例减小,差异有显著性(P<0.05)。糖尿病增殖期组与非增殖期组比较,中央角膜内皮细胞密度降低,角膜内皮细胞变异系数增加及六边形细胞比例减小,差异有显著性(P<0.05),中央角膜厚度增加,但无统计学差异(P>0.05)。
　　结论：糖尿病患者与正常对照者相比,角膜内皮细胞形态结构存在异常,并且随病变程度的加重而加重,尤其以变异系数以及六边形细胞比例变化更为显著,因此糖尿病患者角膜的抗损伤能力下降。     

高糖抑制角膜缘干细胞间质性及其迁移能力的研究

目的　探讨高糖环境对角膜缘干细胞增殖、迁移能力及表面分子标志的影响。方法　通过细胞免疫荧光、细胞增殖检测（CCK-8）、划痕和Transwell实验观察角膜缘干细胞在高糖环境下的迁移及增殖能力的改变。选取16只SPF级大鼠用链脲霉素进行糖尿病造模，14只正常SPF级大鼠作为对照组，刮除两组大鼠角膜上皮观察上皮创伤愈合情况，采用HE染色和免疫组织化学染色探讨糖尿病对角膜缘干细胞表面分子标志及细胞状态的影响。结果　高糖可导致体外培养的角膜缘干细胞增殖减慢，24 h、48 h及72 h增殖率为0.728、0.345及0.395，较对照组明显降低（P<0.05），迁移功能障碍（48 h时正常对照组迁移率为100%，高糖组为17.6%）；高糖组细胞表面分子β-catenin和vimentin的mRNA和蛋白表达水平降低、细胞内定位异常。糖尿病大鼠角膜上皮创伤后愈合延迟，角膜组织HE染色发现糖尿病大鼠角膜上皮层变薄，基底细胞结构紊乱、形态异常。角膜免疫组织化学染色发现与对照组相比，角膜基底细胞的vimentin和β-catenin蛋白表达明显降低。结论　高糖可导致角膜缘干细胞迁移障碍和增殖抑制，其损伤机制与高糖导致角膜缘干细胞表面分子标志的丢失有关。     

糖尿病患者行玻璃体视网膜手术对角膜内皮细胞的影响

目的：探讨糖尿病患者与非糖尿病患者行玻璃体视网膜手术前后对角膜内皮细胞密度和形态学的影响。

方法：收集60例患有糖尿病患者(糖尿病组)和60例非糖尿病患者(对照组),其中30例糖尿病组和30例对照组患者行玻璃体切割联合硅油填充手术,30例糖尿病组和30例对照组患者行晶状体玻璃体切割联合硅油填充手术。检测两组患者术前1d及术后3mo角膜内皮细胞密度(cell densities,CD)、内皮细胞面积变异系数(coefficient of variation,CV)、六角形细胞百分比值(ratio of hexagonal cells,RHC)。比较两组患者手术前后角膜内皮细胞变化的差异。

结果：玻璃体切割联合硅油填充术在糖尿病组与对照组角膜内皮细胞变异系数和六角形细胞百分比手术前后相比差异均有统计学意义, 晶状体玻璃体切割联合硅油填充术在糖尿病组和对照组角膜内皮细胞密度、变异系数及六角形细胞百分比手术前后相比差异均有统计学意义; 晶状体玻璃体切割联合硅油填充术在糖尿病组手术前后角膜内皮细胞密度、变异系数、六角形细胞百分比的差值与对照组相比差异有统计学意义。

结论：玻璃体切割联合硅油填充手术对角膜的影响主要表现在角膜内皮细胞的形态改变; 而与非糖尿病患者相比,糖尿病患者行晶状体玻璃体切割联合硅油填充术角膜内皮细胞形态、密度的改变较非糖尿病患者明显,因此术前角膜内皮细胞的严格检查对于糖尿病患者术后视觉的恢复具有重要意义。     

白内障超声乳化术对糖尿病患者角膜内皮的影响

目的研究糖尿病患者角膜内皮细胞的形态学特点,以及超声乳化手术对其影响.方法将病例分为二组,一组为糖尿病伴白内障35例40眼,另一组为同期手术的普通老年性白内障40例50眼.所有病例均行超声乳化术,术前及术后3个月对术眼角膜内皮细胞进行形态学定量对比分析.结果糖尿病患者角膜内皮细胞密度、六角形细胞比例较正常组下降,平均细胞面积增加(P＜0.05);正常白内障组手术前、后大部分定量指标差异无显著性(P＞0.05),而糖尿病组手术前、后细胞密度减少,平均细胞面积增大,六角形细胞比例下降(P＜0.05).结论糖尿病对角膜内皮细胞的形态和泵功能有一定影响;糖尿病患者角膜内皮对超声乳化吸除术手术损伤较为敏感,术前应常规检查角膜内皮,术中尽量避免损伤角膜内皮细胞.     

白内障超声乳化术对不同病程糖尿病患者角膜内皮细胞的影响

目的：观察不同病程糖尿病患者白内障超声乳化手术后角膜内皮细胞的变化规律,探讨糖尿病及其病程长短对术后角膜内皮细胞的影响。
　　方法：随机选取患有糖尿病的白内障患者97例135眼,根据病程长短分为Ⅰ组(糖尿病病程≥10a)和Ⅱ组(糖尿病病程<10a),另随机选取年龄相关性白内障患者62例89眼作为对照组,分别测量三组患者术前及术后角膜内皮细胞密度、六边形细胞比例、变异系数,对测量结果进行统计学分析。
　　结果：三组患者术后角膜内皮细胞密度和六边形细胞比例与术前相比均呈下降趋势,角膜内皮细胞变异系数在术后1 wk;1 mo与术前相比呈增大趋势,差异有统计学意义( P<0.05);两糖尿病组术后角膜内皮细胞密度及六边形细胞比例均低于对照组,角膜内皮细胞变异系数均大于对照组,差异有统计学意义(P<0.05);两组糖尿病组之间术前角膜内皮细胞密度、六边形细胞比例及内皮细胞变异系数无显著性差异(P>0.05),而术后Ⅰ组六边形细胞比例低于Ⅱ组,内皮细胞变异系数高于Ⅱ组,差异有统计学意义(P<0.05)。
　　结论：白内障超声乳化手术对角膜内皮有一定损伤,由于糖尿病对角膜内皮细胞形态及功能的影响与病程长短有关,手术对糖尿病患者角膜内皮损伤更明显,糖尿病病程越长,手术中角膜内皮越易受损。     

醛糖还原酶抑制剂和肌醇对糖尿病视网膜毛细血管周细胞的保护作用

目的观察醛糖还原酶抑制剂和肌醇对实验性糖尿病大鼠视网膜病变毛细血管周细胞的保护作用。方法给链脲佐菌素诱发的糖尿病大鼠分别管饲醛糖还原酶抑制剂或肌醇，于实验6个月末进行视网膜毛细血管消化铺片及透射电镜观察。结果糖尿病组的视网膜可见毛细血管内皮细胞／周细胞比值升高、无细胞毛细血管形成、周细胞线粒体肿胀、内皮细胞增生和毛细血管基底膜增厚；管饲醛糖还原酶抑制剂组的视网膜血管形态无明显改变；但管饲肌醇组的视网膜血管改变较管饲醛糖还原酶抑制剂组明显。结论醛糖还原酶抑制剂可有效预防实验性糖尿病性视网膜病变的形态学改变，肌醇能部分阻止视网膜形态学异常的发生。     

糖尿病患者角膜内皮细胞的内皮显微镜观察

使用接触型角膜内皮显微镜摄像观察了糖尿病患者６０只眼内皮细胞形态学的变化。结果表明：糖尿病患者角膜内皮细胞的密度与正常人同年龄组比较，差异无显著性；内皮细胞非六边形的比率，患者组较正常同年龄组明显升高。说明细胞构型紊乱很可能是糖尿病患者内皮细胞功能异常的病理学基础。     

我国正常人角膜内皮细胞的计算机分析

目的 探讨我国正常人角膜内皮细胞密度和形态特征，建立细胞密度和形态学的生理学参数。方法 应用接触式角膜内皮细胞显微镜（日本Ｔｏｍｅｙ公司ＥＭ－１０００）及与其联网同步显示的角膜内皮细胞分析仪（日本Ｔｏｍｅｙ公司－１０２０），对我国１５４例（２４４眼）正常人角膜内皮细胞进行了观察和分析。结果 建立了细胞密度和形态学参数。发现：年龄和平均面积、面积标准差、最大细胞面积、最小细胞面积以及五、七角形细胞出     

兔角膜内皮细胞体外原代培养及形态学观察

目的：研究培养兔角膜内皮细胞,为实验提供基础。方法：通过改良的细胞收获,培养技术,在体外进行兔角膜内皮细胞的培养,细胞的类型由电镜证实,观察hEGF不同时间点对角膜内皮细胞生长状态的影响。结果：未加入任何促细胞分裂剂的情况下,细胞在体外生长良好,约一周左右形成密集状态,形态类似天然细胞,经倒置显微镜和电镜证实为角膜内皮细胞。在有hEGF存在时,细胞生长迅速3－4天形成单层,各个时间点EGF组的细胞数高于对照组,结论：该技术可为角膜内皮细胞的研究提供较多的纯内皮细胞。     

Apoptosis mediates decrease in cellularity during the regression of Arthus reaction in cornea

BACKGROUND/AIMS: The Arthus type allergic reaction is characterised by inflammatory cell infiltration and marked neovascularisation in the cornea. During the healing stages, inflammatory cells and newly formed microvessels gradually disappear. The aim was to establish whether apoptosis affected the regression of inflammatory cells and newly formed microvessels, in order to define more clearly the cellular mechanisms involved in the pathobiology of corneal diseases. METHODS: Albino male rabbits were injected subcutaneously with 5 mg/ml bovine serum albumin (BSA) incorporated in Freund's complete adjuvant twice weekly. Under the anaesthesia, 30 microl of a 0.5 mg/ml BSA solution was injected into the central corneal stroma to induce an Arthus type allergic reaction. The injured corneas were collected at various time points ranging from 3 to 20 days. Apoptotic cells were identified by both light microscopy using in situ TdT-dUTP nick end labelling (TUNEL) method and electron microscopy. RESULTS: With increasing time after induction of the Arthus reaction, marked neovascularisation and infiltrated inflammatory cells such as polymorphonuclear cells (PMNs) and plasma cells were observed in the cornea. Thereafter, the inflammatory cells and newly formed microvessels gradually disappeared. Coincidently, the numbers of microvessel endothelial cells and infiltrated inflammatory cells undergoing apoptosis were increased. Apoptotic bodies were taken up by macrophages, PMNs, as well as myofibroblasts derived presumably from transformation of migrated keratocytes. CONCLUSIONS: These data demonstrate that regression of the cellular infiltrates and microvessel endothelial cells associated with the Arthus reaction in the cornea occurs via apoptosis. This finding adds insights into the cellular mechanisms regulating the pathobiology of corneal diseases.     

羊膜载体培养标记兔角膜内皮细胞移植的研究

目的探讨以羊膜基底膜为载体培养兔角膜内皮细胞移植的可能性,为培养内皮细胞移植治疗角膜内皮失代偿疾病提供依据与方法。方法体外培养扩增兔角膜内皮细胞,采用亲脂性碳青染料(CM-DiI)对细胞进行标记,种植于去除上皮细胞的羊膜基底膜上,体外培养形成单层角膜内皮层,并进行形态学、组织学、超微结构及细胞标记情况的观察;将羊膜为载体培养的内皮层对切除后板层的兔角膜进行移植,同时以无培养内皮细胞的羊膜移植和单纯角膜后板层切除为对照,术后观察角膜透明度与厚度,对其进行组织学与细胞标记情况的检测。结果 5～7d 角膜内皮细胞即在羊膜基底膜上融合成单层,细胞为扁平多角形,排列紧密,密度可达(3202.84±347.77)个/mm~2,荧光显微镜下可见内皮细胞被 CM-DiI 标记后显现红色荧光;培养内皮层移植后角膜维持相对的透明与薄度,而无内皮细胞羊膜移植和单纯后板层切除两组对照角膜严重水肿、混浊,厚度明显超过实验组角膜;培养内皮移植后角膜形成新的内皮层,通过标记的细胞发现移植后细胞仍为培养移植的内皮细胞而非周边细胞的移行。结论羊膜基底膜是角膜内皮细胞生长和移植的良好载体,体外培养角膜内皮细胞移植有望代替供体角膜移植,具有广阔的应用前景。(中华眼科杂志,2006,42:925-929)     

Clinical and microstructural analysis of patients with hyper-reflective corneal endothelial nuclei imaged by in vivo confocal microscopy

The purpose of this study was to determine the significance of hyper-reflective corneal endothelial nuclei imaged by in vivo confocal microscopy. A retrospective analysis was performed using a database of 505 patients that had undergone in vivo confocal microscopy of the cornea. All subjects with hyper-reflective endothelial nuclei were identified and these images were analysed to determine corneal endothelial cell density and morphology. The clinical notes of these patients were reviewed and corresponding data regarding corneal thickness was obtained from a related database of Orbscan II pachymetry. Hyper-reflective endothelial nuclei were identified in 41 eyes of 39 (7.7%) patients. Diagnoses included previous cataract surgery or penetrating keratoplasty, posterior polymorphous dystrophy, Fuchs' endothelial dystrophy and irido-corneal endothelial syndrome. No patients with clinically normal corneas exhibited bright endothelial nuclei. The mean endothelial cell density in this group was 1325+/-872 cells mm(-2) and endothelial density was below age-adjusted normal values in 69.2% of patients. Both cellular polymegathism (coefficient of variation of cell area 33.9+/-7.4%) and cellular pleomorphism were noted (51.8+/-9.0% hexagonal cells). The mean central corneal thickness was 582+/-52 microm. There was no significant difference in endothelial density and morphology compared to cases that had low endothelial density but did not exhibit bright nuclei. In conclusion, this study is the first to investigate the significance of bright endothelial nuclei detected by in vivo confocal microscopy. The strong association with corneal disease states suggests that the most likely explanation for this appearance is the alteration in cellular/nuclear morphology, composition or function.     

共焦显微镜在不典型虹膜角膜内皮综合征诊断中应用

目的 探讨共焦显微镜检查在虹膜角膜内皮综合征临床诊断中的应用价值.方法 对8例(其中6例单眼患病,2例双眼患病)常规检查无法确诊的疑似虹膜角膜内皮综合征病例进行共焦显微镜检查.观察角膜内皮层病变结构.结果 活体共焦显微镜检查发现患眼角膜内皮细胞均偏大而且形状不规则,细胞核反光明显增高,可见散在双核、多核、偏位核及分叶核等改变,7例细胞边界模糊,部分病例有局灶内皮细胞缺失、胞内环形暗区、分裂状细胞等改变.此外,3例单眼患病病例的对侧眼在共焦显微镜下发现内皮细胞密度下降、大小不均等改变.最后确诊为原发性进行性虹膜萎缩型2例、Chandler综合征4例、Cogan-Reese综合征2例.结论 共焦显微镜可以在细胞水平上无创、高分辨率地观察到虹膜角膜内皮综合征患眼角膜内皮层特征性的显微结构改变,且不受角膜水肿的影响,大大提高了虹膜角膜内皮综合征诊断的准确性,并有助于早期诊断,具有很高的应用价值.     

Long-term recovery of the human corneal endothelium after toxic injury by benzalkonium chloride

INTRODUCTION: The inadvertent intra-ocular administration of benzalkonium chloride-preserved hydroxypropyl methylcellulose during cataract surgery at another hospital in 1999 resulted in toxic corneal endothelial injury and profound postoperative corneal oedema as a result of endothelial decompensation. The long-term effect of this adverse event was assessed. METHODS: All 19 patients were invited to return for examination including corneal endothelial specular microscopy and pachymetry seven years after the incident. Results were compared with data from one year after the incident. RESULTS: Five patients attended for examination, one had received a penetrating keratoplasty and was, therefore, excluded. Ten patients had died and four had moved out of the region and were unable to attend. All four study patients were pain free and achieved 6/12 or better. Mean central corneal thickness reduced by 13% from 652.6 microm at one year to 563.4 microm. Mean central corneal endothelial cell density (n = 3) increased 28% from 663.7 cells/mm(2) at one year to 835.7 cells/mm(2) (p<0.05). CONCLUSIONS: After toxic injury, corneal endothelial function may have a remarkable capacity for recovery even after the first postoperative year. The rise in central endothelial cell density may represent cell migration from less affected areas or cellular proliferation. Should this unfortunate event recur, clinicians may expect continued recovery beyond one year.     

Ex vivo transfer of Smad7 decreases damage to the corneal endothelium after penetrating keratoplasty

PURPOSE: To determine whether transient gene transfer and expression of the intracellular antagonist of transforming growth factor beta (TGF-beta), Smad7, to corneal endothelial cells decreases corneal endothelial cell damage after penetrating keratoplasty in a rabbit model. METHODS: Rabbit corneas were transfected ex vivo with replication-deficient adenoviruses encoding Flagtagged Smad7, Flag-tagged Smad3, or LacZ (termed AdCMV-Smad7, AdCMV-Smad3, AdCMV-LacZ) and then transplanted to normal rabbits. Expression of the exogenous Smads and phosphorylation of endogenous Smad2 in the transplanted corneal endothelium were examined by immunoblotting and immunohistochemistry with anti-Flag or anti-phosphorylated Smad2 antibodies. Cellular density and morphological changes in the corneal endothelium of the transplanted cornea were evaluated by scanning electron microscopy after transplantation of the Smad-transfected corneas. RESULTS: Transplanted AdCMV-Smad7-transfected corneas significantly inhibited the decrease in cellular density and accelerated wound healing at the host-graft junction when compared with transplanted AdCMV-LacZ-transfected corneas. Transplanted AdCMV-Smad3-transfected corneas showed decreased cellular density and delayed wound healing at the host-graft junction. CONCLUSIONS: Ex vivo gene transfer of Smad7 to corneal endothelial cells inhibits the decrease in cellular density and accelerates wound healing after penetrating keratoplasty in rabbits. Thus, modulation of Smad7 expression in corneal endothelial cells may decrease corneal endothelial cell damage after penetrating keratoplasty.     

Corneal endothelial cytotoxicity of diluted povidone--iodine.

PURPOSE: To assess corneal endothelial toxicity of diluted povidone-iodine (PI) in vivo and in vitro. SETTING: Cell Biology Laboratory and the Laboratory for Intraocular Microsurgery and Implants, Goldschleger Eye Research Institute, Sackler School of Medicine, Tel-Aviv University, Chaim Sheba Medical Center, Tel-Hashomer, Israel. METHODS: In an in vitro study, cultured bovine corneal endothelial cells were exposed to diluted PI. The degree of cell damage was determined by staining with trypan blue and by comparing the results to those in a control group. In an in vivo study, a single dose of diluted PI was injected into the anterior chamber of rabbit eyes, completely replacing the aqueous humor. The eyes were evaluated by clinical examination, specular microscopy, pachymetry, pneumotonometry, and histopathology and compared to a control group injected with a balanced salt solution. RESULTS: In vitro, PI concentrations of 0.05% or less did not induce endothelial cell damage. Significant damage was observed with a PI concentration of 0.1%. Calf serum concentrations of 1% and higher in the culture media protected the endothelial cell monolayer from cytotoxic damage by PI. Aqueous humor did not have a similar effect. In vivo, PI concentrations of 0.1% or less did not induce changes in corneal endothelium morphology or function as assessed by specular microscopy and pachymetry. A PI concentration of 1% served as a positive control, causing corneal edema and endothelial cell loss as demonstrated by pachymetry, histopathology, and elevated intraocular pressure. CONCLUSIONS: The concentrations of PI tolerated by animal endothelium in vitro and in vivo were higher than the reported bactericidal levels. These findings justify further investigation of the safety and efficacy of PI for intracameral prophylaxis during surgery.     

Keratocyte activation and apoptosis in transplanted human corneas in a xenograft model

PURPOSE: To study keratocyte activation and cellular apoptosis in transplanted human corneas during the early postoperative period. METHODS: Ten human donor corneas preserved for 6 days at 4 degrees C were transplanted into the eyes of 10 adult cats. After confocal and specular microscopy in vivo 1 week after keratoplasty, the cats were killed, and the fixed corneas were examined by TUNEL assay and by scanning (SEM) and transmission electron microscopy (TEM). RESULTS: Abnormal keratocytes, in which portions of cell bodies and processes as well as nuclei were visible, were present in all corneas and occupied the anterior 16 to 562 microm of the stroma. By TEM in the same corneas, these abnormalities represented keratocytes that were activated to a repair phenotype. Only 0% to 1% of all corneal cells were apoptotic by TUNEL assay, except for the donor keratocytes near the wound, where 7% were apoptotic. The midstromal keratocyte density was decreased at 13,936 +/- 5,910 cells/mm(3) (mean +/- SD), and the endothelial cell density was 2,298 +/- 688 cells/mm(2), representing an endothelial cell loss of 7% +/- 16%. CONCLUSIONS: Substantial keratocyte activation and low levels of cellular apoptosis occur 1 week after human corneal transplantation. The human-to-cat xenograft model of corneal transplantation demonstrated endothelial cell loss and other clinical findings similar to human allografts. The model will be useful for preclinical testing of new methods of long-term corneal preservation and of donor endothelial cell augmentation, as well as the study of human corneal wound healing and keratocyte replacement during the early postoperative period.     

Repopulation of denuded murine Descemet’s membrane with life-extended murine corneal endothelial cells as a model for corneal cell transplantation

· Background: Corneal endothelial cell transplantation has been an intriguing concept as an alternative to full-thickness penetrating keratoplasty. Using a murine corneal transplantation model, we sought to establish the optimal conditions to repopulate, ex vivo, denuded murine Descemet’s membrane with life-extended cell cultures of murine corneal endothelial cells. These ex vivo repopulated corneas were used as donor corneas in a murine orthotopic corneal transplantation model to assess, in vivo, the function of the transplanted, life- extended murine corneal endothelial cells (MCEC). · Methods: Mouse corneas were surgically trephined and the native corneal endothelium was removed mechanically using a sterile cotton swab. Cultured murine corneal endothelial cells (life extended by expression of the SV40 large T antigen) were added onto the denuded Descemet’s membrane and allowed to attach in culture at 37°C. Evidence of corneal cell attachment to Descemet’s membrane was determined between 1 and 8 h by scanning and transmission electron microscopy. Donor life-extended corneal endothelial cells were labeled with a fluorescent dye to allow tracking of the donor cells following seeding onto denuded Descemet’s membrane. In four independent experiments, the Descemet’s repopulated corneas were placed into syngeneic mice and evaluated for corneal clarity after 6 weeks. · Results: We could detect attachment of the life-extended murine CEC by scanning and transmission electron microscopy to denuded Descemet’s membrane. The optimal time for adherence was 2 h and these repopulated corneas were used as donors in a murine model of penetrating keratoplasty. Of 20 mice evaluated after 6 weeks, 4 displayed corneal clarity, and fluorescent evaluation demonstrated that only the donor corneal endothelial cells were present. · Conclusions: This experimental protocol establishes that ”life- extended” MCEC can bind to Descemet’s membrane ex vivo and form a distinct monolayer. The repopulated Descemet’s membrane allowed us to directly test the hypothesis that cultured life-extended corneal endothelial cells are functional when reintroduced into an in vivo milieu and provides evidence that specific corneal endothelial cell transplantation may be a viable alternative to pentrating keratoplasty. Received: 21 July 1999 Accepted: 22 September 1999     

Effects of intraocular epinephrine on the corneal endothelium of rabbits.

Epinephrine is frequently used in the phacoemulsification to dilate pupils. To determine the effects of different concentration of epinephrine on the corneal endothelial cells, twenty-eight rabbit eyes were equally divided into four groups. Solutions, which contained normal saline, 1:1000 epinephrine, 1:5000 epinephrine and 1:10000 epinephrine respectively, were injected into the anterior chambers of the eyes of four groups of rabbits. In vivo morphological changes of corneal endothelium and changes of thickness were checked with specular microscopy. In vitro morphological evaluation of corneal endothelium was observed in excised corneal buttons stained with alizarin red with trypan blue, and with scanning electron microscopy. Our results showed that there was no significant difference in cell density and corneal thickness among the four groups. Alizarin red with trypan blue stain and SEM exam revealed smooth and distinct cell borders of endothelial cells in each group. Intracameral injection of epinephrine does not produce toxic effect on corneal endothelial cells in rabbits.