Movements of cultured corneal epithelial cells and stromal fibroblasts in electric fields

The effects of an externally applied direct-current electric field on the movement of cultured rabbit corneal epithelial cells and stromal fibroblasts were studied. After a latency of approximately 20 minutes in an electric field, both epithelial cells and stromal fibroblasts became spindle shaped and underwent galvanotropism by aligning their long axes perpendicular to the applied electric field. The electric field stimulus thresholds for galvanotropic movements in epithelial cells and stromal fibroblasts were 4V/cm and 6 V/cm, respectively. After an additional latency of 30 minutes, both cell types manifested galvanotaxic movements: epithelial cells commenced migration in the cathodal (downfield) direction and stromal fibroblasts in the anodal (upfield) direction. For both types of cells, ruffled membranes and lamellipodia were abundant at the leading edges of migrating cells and cell processes underwent retraction at the trailing edges. At field strengths of above 10 V/cm, evidence of cellular damage (manifested by cellular rounding and detachment), attributable to the electric field treatment, was observed after 4 hours. These preliminary results suggest that galvanotaxic responses could be exploited clinically in the enhancement of corneal wound healing.     

The expression of matrix metalloproteinases and their inhibitors in corneal fibroblasts by alarmins from necrotic corneal epithelial cells

Purpose

Sterile ulceration is frequently observed in the cornea following persistent corneal epithelial damage. We examined the effect of alarmins released by necrotic corneal epithelial cells (HCE) on the production of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) by corneal fibroblasts.

Methods

IL-1α and high-mobility group box 1 protein (HMGB1) released into the supernatant derived from necrotic HCE cells were measured with enzyme-linked immunosorbent assay (ELISA). MMPs and TIMPs produced by corneal fibroblasts, stimulated with the supernatant from necrotic HCE cells, were analyzed and measured with protein array and ELISA. To investigate dynamic expression of alarmins in the corneal epithelium, we used immunohistochemistry to observe the expression of human IL-1α in the corneal epithelium of human IL-1α Tg mice with or without cryopexy. We also investigated the expression of MMPs in corneal stroma of the mice treated with cryopexy, using RT-PCR.

Results

We detected IL-1α and HMGB-1 in the supernatant of necrotic HCE cells. These supernatants increased the expression of MMP-3 and MMP-1, and decreased that of TIMP-1 and TIMP-2 in human corneal fibroblasts. Almost always these were inhibited by IL-1 receptor antagonist. Recombinant IL-1α increased the production MMP-3 and MMP-1 in corneal fibroblasts. After cryopexy of the epithelium of human IL-1α Tg mice, the expression of human IL-1α was recognized in the cytoplasm but not nucleus of epithelial cells. The level of MMP-3 and MMP-1 mRNAs was elevated in the corneal stroma in mice treated with cryopexy.

Conclusion

Alarmins, especially IL-1α, released from necrotic HCE cells may play an important role in the expression of MMPs and TIMPs by corneal fibroblast, resulting in sterile ulceration.

     

Acellular porcine corneal matrix as a carrier scaffold for cultivating human corneal epithelial cells and fibroblasts in vitro

AIM: To investigate the feasibility of corneal anterior lamellar reconstruction with human corneal epithelial cells and fibroblasts, and an acellular porcine cornea matrix (APCM) in vitro. METHODS: The scaffold was prepared from fresh porcine corneas which were treated with 0.5% sodium dodecyl sulfate (SDS) solution and the complete removal of corneal cells was confirmed by hematoxylin-eosin (HE) staining and 4’, 6-diamidino-2-phenylindole (DAPI) staining. Human corneal fibroblasts and epithelial cells were cultured with leaching liquid extracted from APCM, and then cell proliferative ability was evaluated by MTT assay. To construct a human corneal anterior lamellar replacement, corneal fibroblasts were injected into the APCM and cultured for 3d, followed by culturing corneal epithelial cells on the stroma construction surface for another 10d. The corneal replacement was analyzed by HE staining, and immunofluorescence staining. RESULTS: Histological examination indicated that there were no cells in the APCM by HE staining, and DAPI staining did not detect any residual DNA. The leaching liquid from APCM had little influence on the proliferation ability of human corneal fibroblasts and epithelial cells. At 10d, a continuous 3 to 5 layers of human corneal epithelial cells covering the surface of the APCM was observed, and the injected corneal fibroblasts distributed within the scaffold. The phenotype of the construction was similar to normal human corneas, with high expression of cytokeratin 12 in the epithelial cell layer and high expression of vimentin in the stroma. CONCLUSION: Corneal anterior lamellar replacement can be reconstructed in vitro by cultivating human corneal epithelial cells and fibroblasts with an acellular porcine cornea matrix. This laid the foundation for the further transplantation in vivo.     

The cytokine regulation of SPARC production by rabbit corneal epithelial cells and fibroblasts in vitro

OBJECTIVE: SPARC (osteonectin/BM40) is detected in the corneal stroma during the wound-healing process. To understand the metabolism of SPARC in the cornea, we investigated the effects of cytokines and growth factors on SPARC synthesis by rabbit corneal epithelial cells and fibroblasts. METHODS: Rabbit corneal epithelial cells or fibroblasts were cultured for 3 days with serum-containing minimal essential medium (MEM), then subcultured for 3 days on serum-free MEM with epidermal growth factor (EGF), platelet-derived growth factor (PDGF), transforming growth factor-beta (TGF-beta), or interleukin-1beta (IL-1beta). SPARC concentration in the medium was measured by the ELISA method using anti-SPARC monoclonal antibody. RESULTS: The concentration of SPARC in the conditioned medium of the epithelial cells depended on either cell numbers or cultivation periods. When EGF was added to the medium, the amount of SPARC in the medium decreased. The addition of IL-1beta, PDGF, or TGF-beta did not affect SPARC synthesis by the epithelial cells. The production of SPARC by rabbit corneal fibroblasts was low compared with that by epithelial cells. However, the synthesis of SPARC by corneal fibroblasts was significantly enhanced by the addition of TGF-beta. The addition of IL-1beta, PDGF, or EGF slightly increased SPARC synthesis by corneal fibroblasts. CONCLUSIONS: Cytokines and growth factors modulate SPARC synthesis by rabbit corneal epithelial cells and fibroblasts. These results suggest that cytokines and growth factors modulate cell-matrix interaction in corneal wound healing, possibly by regulating SPARC synthesis.     

Keratin filaments of corneal epithelial cells

Intermediate filaments with a diameter of approximately 8–10 nm are present in great abundance in the cytoplasm of corneal epithelial cells. In order to study the immunological relationship between these filaments and the tonofilaments of epidermal cells, we prepared an antiserum against keratin proteins isolated from the stratum corneum of human epidermis. Immunofluorescent staining of frozen sections of rabbit and human corneas with this anti-keratin antiserum resulted in the intense staining of the entire corneal epithelium, but no staining of the endothelium or any of the stromal components. Similar staining of cultured rabbit and human corneal epithelial cells revealed a cytoplasmic network of wavy fibers distinct from microfilaments and microtubles. Electron microscopic examination of cultured rabbit corneal epithelial cells showed that they formed a stratified squamous structure with prominent desmosomal cell-cell junctions and wavy bundles of cytoplasmic 8–10 nm filaments. These results suggest that the 8–10 nm filaments of corneal epithelium are immunologically related to tonofilaments of the epidermis and are composed of keratin proteins. Since corneal epithelium is the only keratin-containing cell type in normal cornea, anti-keratin staining provides a simple, specific and sensitive method for identifying corneal epithelial cells. Further characterization of the keratins synthesized by corneal epithelial cells under various in vivo and in vitro conditions may provide useful information concerning the mechanisms of corneal epithelial differentiation.     

人角膜基质细胞诱导人骨髓间充质干细胞分化为角膜上皮细胞的初步研究

目的 探讨人骨髓间充质干细胞（MSC）体外分化为角膜上皮细胞的可行性.方法 实验研究.分别取第3代人MSC和自行培养的第3代人角膜基质细胞共同培养1周,实验组在Transwell共培养体系中培养,对照组不放置Transwell小室培养.1周后,观察实验组和对照组中人MSC光镜特征、间接免疫细胞化学染色和电镜结构,对被诱导分化的细胞进行综合鉴别.结果 第3代人MSC和人角膜基质细胞在体外培养条件下均能够较快贴壁生长.两种细胞共同培养1周后,可见部分细胞形态上呈上皮细胞特征,单克隆抗体AE1染色呈阳性,电镜下可见微绒毛、桥粒和张力丝等典型上皮细胞结构特征.结论 体外培养的人MSC在人角膜基质细胞的诱导下可能会分化为人角膜上皮样细胞.     

Longterm survival of transplanted human corneal epithelial cells and corneal stem cells

PURPOSE: To investigate the survival of donor-derived epithelial cells in conventional penetrating keratoplasty (PKP) and in homologous penetrating central limbal keratoplasty (HPCLK). METHODS AND PATIENTS: Epithelial cells from 26 eyes of 26 patients were analysed. All cases were sex-mismatched (i.e. the transplant and patient were of different genders). At suture removal more than 1 year post surgery, epithelial cells were obtained by gently wiping the removed sutures on glass slides. The cell samples were analysed using fluorescent in situ hybridization (FISH) of the sex chromosomes. This technique makes it possible to allocate the origin of each cell nucleus to either the donor or the recipient. RESULTS: All 19 conventional PKPs were clear and seven had donor-derived epithelial cells at suture removal. Five of the seven HPCLK grafts were clear at the time of investigation (365-1355 days post surgery), and donor-derived epithelial cells were found in two grafts. CONCLUSION: Harvesting cells from removed sutures in combination with FISH enables the clinical study of cell survival in corneal transplants without jeopardizing functioning grafts. From the limited sample investigated, the following tentative conclusions can be made. Donor-derived epithelial cells can remain in conventional PKP for over 1 year. In combined stem cell and corneal grafts (HPCLK), donor-derived epithelial cells may also be retrieved at 1 year or beyond following surgery but the correlation between their presence and a remaining clear graft is uncertain.     

Longterm survival of transplanted human corneal epithelial cells and corneal stem cells

PURPOSE: To investigate the survival of donor-derived epithelial cells in conventional penetrating keratoplasty (PKP) and in homologous penetrating central limbal keratoplasty (HPCLK). METHODS AND PATIENTS: Epithelial cells from 26 eyes of 26 patients were analysed. All cases were sex-mismatched (i.e. the transplant and patient were of different genders). At suture removal more than 1 year post surgery, epithelial cells were obtained by gently wiping the removed sutures on glass slides. The cell samples were analysed using fluorescent in situ hybridization (FISH) of the sex chromosomes. This technique makes it possible to allocate the origin of each cell nucleus to either the donor or the recipient. RESULTS: All 19 conventional PKPs were clear and seven had donor-derived epithelial cells at suture removal. Five of the seven HPCLK grafts were clear at the time of investigation (365--1355 days post surgery), and donor-derived epithelial cells were found in two grafts. CONCLUSION: Harvesting cells from removed sutures in combination with FISH enables the clinical study of cell survival in corneal transplants without jeopardizing functioning grafts. From the limited sample investigated, the following tentative conclusions can be made. Donor-derived epithelial cells can remain in conventional PKP for over 1 year. In combined stem cell and corneal grafts (HPCLK), donor-derived epithelial cells may also be retrieved at 1 year or beyond following surgery but the correlation between their presence and a remaining clear graft is uncertain.     

Bacterial invasion of corneal epithelial cells.

PURPOSE: The normal ocular surface is frequently colonized by commensal gram-positive species. Gram-negative bacteria are often implicated in corneal infection and inflammation, particularly in association with soft contact lens wear. The aim of this study was to elucidate possible mechanisms of virulence in ocular bacteria. METHODS: The susceptibility of a human corneal epithelial cell line to bacterial invasion and association was evaluated using the gentamicin exclusion assay. Organisms tested included isolates from corneal ulcers, corneal inflammation and ocular sites in asymptomatic individuals. RESULTS: The commensal, non-pathogenic bacterium Staphylococcus epidermidis and some pathogenic strains of Serratia marcescens did not invade corneal epithelial cells. In contrast, pathogenic strains of Pseudomonas aeruginosa associated with and invaded corneal epithelial cells. CONCLUSIONS: The increased association of P. aeruginosa, compared to other bacterial types, might be a reason for the more frequent association of this bacterium with contact-lens-associated microbial keratitis.     

人角膜上皮干细胞的识别

目的 探讨人角膜上皮干细胞的分子标记。方法 对人角膜和角膜缘部位行组织学检查以分析角膜缘解剖结构。对人角膜切片和整个角膜组织行免疫组织化学染色以检测中央角膜和角膜缘部位未分化标记,如核蛋白p63、乳腺癌抵抗蛋白（ABCG2,BCRP1）、烯醇化酶α、整合素拍、胡及β1、表皮生长因子受体（EGFR）、细胞角蛋白19（CK19）、14（CK14）及转铁蛋白受体（CDT1）的表达,经荧光显微镜和激光扫描共焦显微镜观察。对角膜中部和角膜缘上皮细胞的mRNA进行半定量逆转录聚合酶链反应（RT—PCR）和原位杂交以检测其相关基因的表达。结果 角膜缘部位横向切片显示角膜缘上皮细胞为乳头放射状排列,对应于Vogt栅栏环境。未分化标记整合素β1、EGFR、烯醇化酶α及CK19在角膜缘基底细胞胞质染色较表层细胞更强;p63、ABCG2、整合素胡蛋白仅见于角膜缘基底部上皮细胞。激光扫描共焦显微镜观察和RT—PCR结果显示角膜缘表达p63、ABCG2、整合素胡蛋白及mRNA。原位杂交显示p63仅表达于角膜缘基底层细胞。结论 角膜缘上皮呈乳头放射状排列,角膜缘干细胞群具有复合标记：p63表达于细胞核、ABCG2表达于胞质、整合素胡表达于胞膜。采用这些标记复合体,可将角膜缘干细胞群与其他上皮细胞区分。     

Preservative cytotoxicity to cultured corneal epithelial cells

Cultured human and rat corneal epithelial cells with 51Cr incorporated were used as a model to test the cytolytic action of four common preservatives. Benzalkonium chloride, chlorohexidine and thimerosol were all found to lyse greater than 40% cells when incubated for fifteen minutes at concentrations in clinical use in topical ophthalmic medications. Chlorobutanol is the only preservative tested which has a low level of cytotoxicity (10%) and which, under these conditions, can be considered a safe preservative using cytolytic activity as the means of criteria.     

Carboxymethylcellulose binds to human corneal epithelial cells and is a modulator of corneal epithelial wound healing

PURPOSE: In this study, the ability of carboxymethylcellulose (CMC), used in artificial tear formulations, to interact with corneal-epithelial-cells (HCECs) and facilitate corneal epithelial wound healing was investigated. METHODS: HCECs were incubated with fluorescein-labeled CMC (F-CMC). CMC-epithelial binding was measured by spectrophotometry. The effect on F-CMC binding by hyaluronic acid (HA) or glucose was measured after preincubation in HA, mAb to CD44, or glucose, or mAb to GluT-1. F-CMC binding to fibronectin or collagen was measured by incubating proteins with F-CMC. The wound widths were measured 18 hours after confluent HCECs were scratch wounded. The ability of CMC to induce cell chemotaxis, proliferation, or migration was measured by quantitative assay. The efficacy of CMC in promoting epithelial wound healing was also tested in a rabbit epithelial scrape-wound model. RESULTS: CMC remained bound to the HCECs for 2 hours. Preincubation of HCECs with glucose or mAb to GluT-1, but not with HA or mAb to CD44, reduced the binding of CMC to HCECs from 43.7% to 67.2% or 10.9% to 25.3%, respectively. CMC bound significantly to fibronectin (3.1-fold) or collagen (9.3-fold) compared with the control (BSA), and such binding enhanced cell adhesion. CMC stimulated re-epithelialization of HCECs scratched in vitro and in vivo rabbit cornea epithelial scrape wounds. CMC stimulated cell migration but not proliferation. CONCLUSIONS: CMC probably binds to HCECs through interaction of its glucopyranose subunits with glucose transporters. CMC binding to the matrix proteins stimulated HCEC attachment, migration, and re-epithelialization of corneal wounds.     

以纤维蛋白凝胶为载体培养兔角膜缘上皮细胞

目的 研究兔角膜缘上皮细胞(corneal limbus epithelial cell,CLEC)在纤维蛋白凝胶上的最佳接种方式及其生长情况.方法 取角膜缘上皮组织块进行细胞培养.用针对鼠抗兔角蛋白3(CK3)的单克隆抗体AE5和抗增殖细胞核抗原(PCNA)抗体行间接免疫荧光鉴定.MTT法测定CLEC增殖活性.将传第二代的细胞分A、B两组分别接种到纤维蛋白凝胶表面和凝胶体内进行培养,在接种后5d、10 d、15 d时将凝胶溶解离心后计数细胞数,比较两种接种方式下细胞的增殖力.结果 传第一、二代细胞培养3～5d后胞浆AE5染色阳性,胞核PCNA染色阳性,传第一代阳性细胞比例分别为31％、65％,传第二代阳性细胞比例分别为45％、79％.传第一代细胞在接种后6h内贴壁,1～2d时处于潜伏期,2～3 d时处于快速生长期,3d时达85％以上汇合,细胞增殖活性最高,4d时细胞汇合达95％以上,增殖活性逐渐降低.接种后5d时A组细胞数低于B组,差异有统计学意义(P＜0.05);10d和15 d时A组细胞数均高于B组,差异均有统计学意义(均为P ＜0.05).结论 以纤维蛋白凝胶为载体培养CLEC时将细胞接种在凝胶表面比包埋在凝胶体内更有利于细胞增殖,适合用于CLEC移植培养的研究.     

Functions of MUC16 in corneal epithelial cells

PURPOSE: The membrane-associated mucin MUC16, a heavily O-glycosylated transmembrane protein, is expressed by the ocular surface epithelia and localized on the tips of the surface microplicae. Although its functions in the ocular surface glycocalyx are unknown, it is thought that MUC16 provides a disadhesive barrier to the epithelial membrane. Two other membrane-associated mucins expressed by ocular surface epithelia, MUC1 and MUC4, are multifunctional and have signaling capabilities through their cytoplasmic tails and EGF-like domains, respectively. The MUC16 cytoplasmic tail has not been characterized, but, because it contains a polybasic amino acid sequence, it potentially interacts with the actin cytoskeleton through ezrin/radixin/moesin (ERM) actin-binding proteins. METHODS: The interaction of MUC16 with the actin cytoskeleton through ERMs was investigated using cytoplasmic tail peptides and ERM pull-down experiments. MUC16 functions were determined using RNA interference in immortalized human corneal-limbal epithelial (HCLE) cells. The effect of MUC16 knockdown on microplicae structure in HCLE cells was determined using scanning and immunoelectron microscopy. HCLE cells were incubated with rose bengal dye to measure the role of MUC16 in ocular surface barrier function. Binding of fluorescently labeled Staphylococcus aureus to HCLE cells was measured to determine the role of MUC16 in the protection of pathogen adherence on the ocular surface epithelium. RESULTS: MUC16 cytoplasmic tail peptides bound the N-terminus of ERMs, with no detectable binding of MUC1 and MUC4 peptides. No effect on surface membrane projections could be detected in HCLE cells after MUC16 suppression; however, HCLE cells incubated with rose bengal showed that exclusion of the dye was significantly reduced in cells with MUC16 suppression. In addition, S. aureus binding to HCLE cells was significantly increased with MUC16 suppression. CONCLUSIONS: These results suggest that MUC16 is a multifunctional molecule linked to the actin cytoskeleton. The expression of MUC16 in the ocular surface glycocalyx helps provide a disadhesive protective barrier for the epithelial surface.     

角膜上皮干细胞定位及功能的研究进展

角膜上皮干细胞定位于角膜缘已被广泛认可,并被命名为角膜缘干细胞,且认为角膜缘干细胞在角膜上皮的自我更新和损伤修复中起重要作用.但近年来的一些研究却提出了与之相悖的观点:整个眼表层均含有寡能干细胞,且角膜缘干细胞在维持自我更新及稳态方面并未起到至关重要的作用.这些发现提示可能还有其他干细胞存在并维持着角膜上皮的自我更新,但也有人对这些新观点提出质疑.本文通过对最新研究的不同观点及证据的阐述,对近年来角膜上皮干细胞的定位及其功能等方面的进展作一综述.     

乙醇对角膜上皮瓣活性及基底膜分离定位研究

目的 探讨不同乙醇作用时间对角膜上皮瓣活性的影响,并确定角膜上皮瓣的解剖分离层面.方法 按标准准分子激光角膜上皮瓣下磨镶术(LASEK)方法制备7只尸体眼角膜上皮瓣,其中对照组1只眼,其余6只分为A、B、C 3个组,每组2只眼,乙醇浸润时间分别为20、30和40 S.对7只眼进行HE、增殖细胞核抗原(PCNA)、层黏连蛋白免疫组化及Ⅶ型胶原免疫荧光染色,评价角膜上皮瓣细胞活性,确定LASEK手术中角膜上皮瓣的解剖分离层面,采用X2检验分析.结果 角膜上皮瓣为复层上皮细胞组织,没有Bowman's层和角膜基质成分,PCNA阳性细胞率为A组B组C组,其laminin染色在角膜床和上皮瓣基底膜一侧均有呈片段样棕色条纹状,其collagenⅦ染色阳性反应呈一条绿色线形,而且只存在于角膜床,上皮瓣基底膜侧不着色.结论 角膜上皮瓣活性随乙醇浸润时间延长而降低;乙醇浸润法制备角膜上皮瓣的组织分离层面位于角膜上皮基底膜内,并且定位于基底膜的透明层和致密层之间.     

A technique for obtaining basal corneal epithelial cells

A technique has been developed for obtaining a cell suspension enriched (89%) in basal corneal epithelial cells. Eleven millimeter corneal buttons were removed and placed in culture medium containing low (10 microM) calcium. The posterior half of the stroma was removed with forceps. Three superficial cuts were made with a Bard-Parker blade on the anterior half of the cornea, which was then incubated for 18 hr at 35 degrees C. Nonadherent cells were brushed off after the incubation and basal cells were harvested after a 1-hr incubation in Dispase II. Cell viability estimated by Erythrocin beta exclusion was 90%. Further evidence of viability was that the cells adhered to their native substrate, the denuded basal lamina. The authors protocol provides a method for analyzing the biochemistry of a known population of epithelial cells and makes available a defined source of cells for culture.     

Evaluation of corneal damage caused by iodine preparations using human corneal epithelial cells

Purpose

To compare the cytotoxicity of povidone–iodine solution (PVP-I) with that of polyvinyl alcohol–iodine solution (PAI) for ophthalmic use.

Methods

Cells of the human corneal epithelial cell line HCE-T were exposed to various dilutions of PVP-I or PAI, and the cytotoxicity of these two antiseptics was evaluated. The relative toxicities of PVP-I and PAI were also investigated following the inactivation of iodine by achromatization with sodium thiosulfate.

Results

PVP-I and PAI had equivalent antiseptic effects, but the cytotoxicity of PVP-I diluted 16-fold was higher than that of PAI diluted 6-fold. Following inactivation of iodine with sodium thiosulfate, the cytotoxicity of PVP-I remained concentration dependent, whereas PAI exhibited a low toxicity that was similar to the effect of saline on cell viability. Exposure to lauromacrogol, a surfactant used in PVP-I, in solution at concentrations of 1–1000 mg/mL clearly resulted in corneal cytotoxicity. The PVP-I and PAI solutions had a pH value of 4.0 and 5.2, respectively. HCE-T cells were significantly more viable at pH 7 than at pH 1–6.

Conclusion

To avoid corneal damage, preoperative antisepsis of the surgical field should be accomplished with PAI diluted 6-fold, rather than with PVP-I diluted 16-fold. The toxicity of the iodine compound stems primarily from the available iodine concentration and partly from its pH, surfactant and osmolality. Further clinical investigations are required in order to determine the optimal concentrations for use.     

聚维酮碘对角膜上皮细胞氧化损伤的影响

目的：观察聚维酮碘对角膜上皮细胞氧化损伤的影响。

方法：观察不同浓度聚维酮碘对角膜上皮细胞氧化损伤的影响,取体外培养的生长良好的角膜上皮细胞按随机数字法分为：对照组、低浓度组、中浓度组和高浓度组。观察不同消毒时间聚维酮碘对角膜上皮细胞氧化损伤的影响,取体外培养的生长良好的角膜上皮细胞按随机数字法分为：对照组、短时间组、中等时间组和长时间组。采用ELISA检测各组丙二醛(MDA)、超氧化物歧化酶(SOD)含量,采用倒置显微镜、CCK-8法检测各组细胞活性,采用流式细胞仪检测各组细胞的凋亡率。

结果：聚维酮碘浓度越高,角膜上皮细胞的MDA含量越高,SOD含量越低,细胞活性越低,凋亡率越高。聚维酮碘对角膜上皮细胞的氧化损伤呈浓度依赖性,组间有差异(均P<0.01)。聚维酮碘消毒时间越长,角膜上皮细胞的MDA含量越高,SOD含量越低,细胞活性越低,凋亡率越高。聚维酮碘对角膜上皮细胞的氧化损伤呈时间依赖性,组间有差异(均P<0.01)。

结论：聚维酮碘对角膜上皮细胞有氧化损伤作用,损伤呈浓度和时间依赖性。