人工角膜在兔角膜内的生物学反应

目的评价3种不同直径人工角膜在动物体内应用的生物学反应.方法将35只兔随机分为Ⅰ组(11只)、Ⅱ组(12只)、Ⅲ组(12只),分别植入3种不同直径人工角膜(4.5～7.0 mm、 7.0～9.0 mm、4.5～6.0 mm),术前将人工角膜进行纤维细胞组织培养,光学中心前表面经rf-argon plasma处理后植入兔眼,观察术后人工角膜在兔角膜中的存留,观察时间＞6个月;并分别于术后2、3、4及6周摘取兔植入人工角膜行组织及病理学检查.结果术后2周成纤维细胞可沉积在人工角膜周边多孔支架内;3周时Ⅲ组角膜上皮细胞位于人工角膜光学中心,Ⅰ、Ⅱ组未见细胞生长.4周时人工角膜内可检测出胶原蛋白沉积.前房稳定,未见房水渗漏.术后6周时人工角膜的周边支架中检测出heparan sulfate(HS)及碱性成纤维细胞生长因子,后者存在于周边支架和宿主角膜的交接处.结论体外人工角膜组织培养可增加人工角膜周边支架的纤维化,稳定光学中心;人工角膜经 rf-argon plasma处理可增加材料的组织相容性;兔角膜缘上皮细胞可迁徙至人工角膜光学中心的前表面.     

羟基磷灰石表面改性人工角膜支架植入兔角膜后基质金属蛋白酶-2及胶原纤维的表达

目的 探讨经羟基磷灰石(HA)表面改性的三襻式人工角膜钛支架植入兔角膜板层后基质金属蛋白酶-2(MMP-2)及胶原纤维的表达,评价其生物相容性.方法 实验研究.24只新西兰白兔采用单纯随机抽样方法随机分为3个组,HA-Ti支架组(9只)及Ti支架组(9只)分别于右眼角膜板层植入HA表面改性后的三襻式人工角膜钛支架(HA-Ti)及人工角膜钛支架(Ti),6只仅制备囊袋不植入支架作为对照组.观察人工角膜支架的生物相容性及新生血管生长情况,并分别于术后2周、4周、16周取材,角膜组织行苏木素-伊红染色、并用免疫组织化学方法检测各组角膜基质中MMP-2的表达并进行半定量分析;用苦味酸天狼猩红苏木素染色的方法观察支架植入后对胶原的影响.多组间比较应用单因素方差分析,组间两两比较应用SNK-q检验.结果 观察期间Ti-HA支架组及Ti支架组均未见角膜感染、溶解、支架排出.早期实验组角膜有水肿及新生血管长入,HA-Ti支架组新生血管明显多于Ti支架组.组织学观察术后2周,植入HA-Ti支架组角膜基质内2周可见少量炎性细胞(中性粒细胞及噬酸细胞为主),此后逐渐减少.支架周围2周时可看到较多成纤维细胞,16周时成纤维细胞减少,粉染的胶原纤维增多.术后2周,HA-Ti支架组、Ti支架组及对照组MMP-2阳性细胞IOD值分别为103.729±15.112、84.439±13.699、69.310±13.078,组间比较差异有统计学意义(F =6.083,P＜0.05),但Ti支架组和对照组差异无统计学意义(F=3.209,P＞0.05);4周时3个组MMP-2阳性细胞IOD值逐渐降低,分别为88.963±9.017、53.005±4.605、49.326±4.443,组间比较差异有统计学意义(F=47.074,P＜0.01);16周时3个组MMP-2阳性细胞IOD值分别为72.176±12.815、50.014±8.813、46.734±11.670,组间比较差异有统计学意义(F=6.079,P＜0.05).偏光镜下观察见角膜组织内4周有大量绿色的Ⅲ型胶原纤维及黄红色Ⅰ型胶原纤维,16周时角膜内主要为鲜红色的Ⅰ型胶原纤维,仍有少量的Ⅲ型胶原纤维.结论 兔角膜植入HA-Ti支架引起MMP-2活化,持续高表达并未造成对角膜的溶解;其影响周围角膜细胞外基质中Ⅲ型胶原纤维向Ⅰ型胶原纤维的转化,利于支架稳定,HA-Ti支架具有较好的生物相容性.     

HA表面改性人工角膜钛支架生物相容性动物实验研究

目的 经羟基磷灰石(hydroxyapatite,HA)表面改性的三襻式人工角膜钛支架植入兔角膜板层探讨其与角膜组织的生物相容性及组织愈合情况.方法 24只新西兰白兔随机分为A、B、 C 3组,A组(9只)及B组(9只)分别于右眼角膜板层植入HA表面改性后的三襻式人工角膜钛支架(HA-Ti)及人工角膜钛支架(Ti);C组(6只)为手术对照组,仅制备囊袋不植入支架.观察人工角膜支架的生物相容性及新生血管生长情况,并分别于术后2周、4周、16周取材,行组织病理学及支架表面组织扫描电镜观察.结果 观察期间A、B组均未见角膜感染、溶解、支架排出.早期实验组角膜有水肿及新生血管长入,A组新生血管明显多于B组.组织学观察术后2周,A组炎症细胞浸润重于对照C组及B组(P<0.05);4周和16周时A、B和C组各组间炎症反应无明显差别(P>0.05).A组支架周围基质成纤维细胞增生显著,术后2周、4周A组和B组成纤维细胞增生均多于对照C组(P<0.05),且A组增生明显多于B组(P<0.05);术后16周时各组间差异无统计学意义(P>0.05).扫描电镜HA-Ti支架表面角膜组织黏附好,胶原纤维与支架连接紧密.结论 HA表面改性三襻式钛支架促进角膜血管化,有利于人工角膜的稳定,使人工角膜支架具有良好生物相容性及促进组织界面愈合能力.     

人工角膜支架材料在动物体内应用的生物学反应

目的 探讨3种人工角膜支架材料经氩等离子体（Argon plasma)处理后植入兔角膜对角膜组织的生物学反应的影响。方法 选用3种支架材料：由80％的聚丙烯和20％聚丁烯化合而成的多孔材料；Polyester多孔材料；Expended polytetrafluoroethylene。处理组材料经Argon plasma处理。将盘状支架材料植入兔角膜囊袋内。结果 材料经处理后角膜水肿较未处理明显减轻，8周后3种材料中角膜水肿均消失。材料1，2植入时新生血管出现延迟，范围小，炎细胞浸润明显减少。术后6周纤维细胞迁徙入材料内。当材料植入角膜后角化蛋白（KS）含量降低，Dermatan(DS)含量增高，并有大分子葡萄糖聚糖（GAG）出现。结论 Argon-plasma处理可明显减轻兔角膜炎症反应，增加材料的组织相容性。     

不同位置角膜缘切口对Toric ICL植入术后角膜散光影响的临床观察

目的 观察不同位置角膜缘切口对Toric ICL后房人工晶状体植入术后角膜散光影响.方法 选择44例(88只眼)高度近视且为顺规性散光患者,随机均分为上方陡轴和颞侧水平角膜缘切口组,表麻下后房人工晶状体植入,IOLmaster测量术前、术后1周、1个月和3个月角膜曲率,观察手术前后角膜散光变化.结果 上方陡轴角膜缘切口组(A组)和颞侧水平角膜缘切口组(B组)术前角膜散光分别为(-2.27±0.80)D和(-2.21±0.84)D(t =0.224,P=0.824),角膜散光陡轴方向平均为(89.6±8.52)°,均为顺规性散光者.术后1周,A组和B组角膜散光分别为(-1.53 ±0.87)D和(-2.77±0.83)D(t =5.059,P=0.000);术后1个月,A组和B组角膜散光分别为(-1.90±0.84)D和(-2.42±0.79)D(t=2.222,P=0.031);术后3个月,A组和B组角膜散光分别为(-1.96±0.76)D和(-2.35±0.78)D(t =1.761,P=0.085).结论 上方陡轴角膜缘切口能一定程度减少顺规性角膜散光,与颞侧水平角膜缘切口相比无明显优势.     

多孔纳米羟基磷灰石-聚乙烯醇水凝胶人工角膜的实验研究

目的 评价多孔纳米羟基磷灰石-聚乙烯醇水凝胶(NHA-PAH)人工角膜在兔角膜内的生物学反应。方法 将NAH-PAHKPro加工成直径10．0mm，周边支架为2．5mm．中央光学部与裙袢连接部呈阶梯状，植入10只新西兰白兔角膜板层囊袋内。术后眼前段裂隙灯照相并分别于1月、2月、3月、4月、6月行术眼角膜组织病理学检查。结果 术后1个月大部分新生血管长入角膜中央，3月时新生血管生长达到高峰，术后6个月角膜中央存留大量变细的新生血管，未见人工角膜排出、基质融解、房水渗漏和感染。HE染色见术后1个月时成纤维细胞、新生血管及少量炎细胞长入裙袢孔隙内，伴有少量胶原形成。术后3个月所有孔隙均被胶原细胞和新生血管组织充填，成纤维细胞在孔隙内沿纵行方向一致性生长，胞头丰富，胞核小。中央光学部透明。结论 NHA-PAHKPro组织相容性好，具有临床应用的前景。     

Argon—Plasma对人工角膜支架材料组织相容性的影响

目的 探讨3种人工角膜支架材料经Argon-Plasma处理后植入兔膜对兔角膜组织的影响。方法 选用3种支架材料：材料1：聚丙烯和聚丁烯（80:20）化合而成的多孔材料;材料2：Polyester多孔材料;材料 3:Expended polytetrafluoroethglene。上述3种材料切成直径6mm的圆盘状,每种材料分为处理组和非处理组。处理组材料经Argon-Plasma处理。选用63只新西兰大白兔,共分为7组,每组9只,6组为实验组及对照组（3组为处理组,3组为非处理组）,1组为手术对照组。以显微手术的方法,将盘状支架材料植入囊袋内,手术对照组仅制备囊袋不植入材料。术后定期观察角膜水肿及新生血管的生长情况。术后28、42、84d取角膜进行角膜组织学及免疫组织化学分析。结果 当材料经处理后角膜水肿较未处理明显减轻,8周后3种材料中角膜水肿均消失。材料1、2植入时新生血管出现延迟,范围也较小,同时炎细胞浸润明显减少。术后6周纤维细胞迁徒入材料内,术后12周空腔填充大量纤维细胞。材料处理与否不影响胶原蛋白的沉积。结论 Argon-Plasma处理可明显减轻兔角膜炎症反应,增加材料的组织相容性。     

改良聚羟乙基丙烯酸甲酯-聚甲基丙烯酸甲酯一体化人工角膜植入兔与猴角膜的实验研究(英文)

目的:探讨聚羟乙基丙烯酸甲酯(PHEMA)海绵支架材料与角膜组织的生物相容性,评价改良聚羟乙基丙烯酸甲酯(PHEMA)—聚甲基丙烯酸甲酯(PMMA)一体化人工角膜植入兔与猴角膜的初步临床效果。方法:通过两个阶段化学聚合结合车床机械切削合成改良的一体化人工角膜。实验分为两个部分完成。第1部分(A组):将PHEMA海绵边裙材料植入10只正常兔角膜板层间,术后2,4wk及2,3,4mo分别行组织病理、免疫组织化学及电镜检查,观察海绵边裙与角膜组织的生物学愈合情况。第2部分(B组):8只兔眼和2只猴眼角膜囊袋内I期植入一体化人工角膜,术后临床观察材料与组织的愈合情况;术后3mo时行Ⅱ期手术切除术眼角膜中央前板层角膜组织,暴露人工角膜中央镜柱,术后随访时间3 ～6mo,初步观察临床治疗效果。结果:1)A组接受角膜板层间边裙植入术的10只兔眼,随访期间未见并发症:组织病理学显示,PHEMA海绵边裙材料植入术后2wk始有成纤维细胞长入,术后2 ～3mo时多量成纤维细胞长入并伴有新生血管生长;免疫组织化学显示,海绵孔隙中长入的细胞和角膜基质细胞均对波形蛋白免疫反应呈阳性;电镜下可见,成纤维细胞在海绵材料间隙中生长,细胞生长状态良好,并分泌胶原和细胞外基质。2)B组接受一体化人工角膜移植术的,6只兔眼一体化人工角膜均在位,另2只兔眼I期术后有前板层角膜基质融解。接受一体化人工角膜移植术的2只猴眼,I期和Ⅱ期术后均未见明显并发症。结论:PHEMA海绵能与角膜组织良好的生物学愈合;改良PHEMA-PMMA一体化人工角膜植入术后能获得相对稳定的治疗效果。     

自体血清与小牛血去蛋白眼用凝胶治疗兔角膜碱烧伤的比较

目的:通过建立兔角膜碱烧伤模型,比较自体血清与小牛血去蛋白眼用凝胶在兔角膜碱烧伤治疗中的效果。方法:制作兔右眼角膜碱烧伤模型30眼,造模后碱烧伤分度全部为Ⅲ度烧伤,将其随机分为三组,分别采用生理盐水、小牛血去蛋白眼用凝胶及自体血清滴眼液4次/d,各组滴阿托品眼用凝胶1次/晚,氧氟沙星眼用凝胶1次/晚,连续2wk。治疗7、14d后观察角膜新生血管形态并计算面积;第14d处死各组实验动物后,摘除双眼角膜,其中左眼为正常对照,右眼为实验眼,分别进行常规组织病理学检查,角膜组织匀浆内CD45、IL-10、IFN-γ及VEGF浓度测定。结果:治疗7、14d后小牛血去蛋白眼用凝胶组角膜新生血管面积(29.48±2.27、34.19±2.67mm2)与自体血清组(34.19±2.67、33.89±2.74mm2)无差异(P>0.05)。治疗14d角膜组织匀浆测定:小牛血去蛋白眼用凝胶组(0.56±0.04ng/mL)和自体血清组(0.54±0.05ng/mL)CD45含量均小于生理盐水组(1.27±0.07ng/mL)(P<0.05);自体血清组(452.49±11.40pg/mL)和小牛血去蛋白眼用凝胶组(332.49±13.67pg/mL)IL-10含量均大于生理盐水组(111.05±6.95pg/mL)(P<0.05);小牛血去蛋白眼用凝胶组(23.20±2.89pg/mL)和自体血清组(22.61±2.72pg/mL)IFN-γ含量均小于生理盐水组(41.77±4.26pg/mL)(P<0.05);小牛血去蛋白眼用凝胶组(151.14±18.21pg/mL)和自体血清组浓度(149.11±14.75pg/mL)VEGF含量均小于生理盐水组(391.35±28.59pg/mL)(P<0.05)。结论:兔角膜碱烧伤后抑制炎症因子CD45、IFN-γ及VEGF释放及抑制角膜新生血管形成方面,自体血清与小牛血去蛋白眼用凝胶作用相当;在促进抗炎因子IL-10释放、抑制炎症细胞浸润方面,自体血清作用强,小牛血去蛋白眼用凝胶次之。     

去除上皮瓣的微型角膜刀法准分子激光角膜上皮瓣下磨镶术后早期兔角膜的修复方式研究

目的 通过对兔微型角膜刀法准分子激光角膜上皮瓣下磨镶术(Epi-LASIK)和去除上皮瓣的(Flap-free)Epi-LASIK术后早期角膜组织的研究,探讨两种手术方式各自在角膜愈合方式方面的特点.方法 实验研究.27只实验兔,24只按不同取材时间1、2、4、7 d采用随机数字表法分为4组,每组6只兔,一只眼行Epi-LASIK,另一只眼行Flap-free Epi-LASIK手术.另3只兔作为空白对照组.用VISX20/20准分子激光仪作-10.00 D切削,另3只兔作为空白对照,通过观察术后1、2、47 d角膜上皮愈合方式、检测角膜基质细胞数量、碱性成纤维细胞生长因子(bFGF)、角膜基质细胞凋亡的表达来探讨Flap-free Epi-LASIK、Epi-LASIK两种术式术后早期角膜创伤愈合方式的差别.对Epi-LASIK和Flap-free Epi-LASIK术后角膜基质bFGF表达、细胞数量变化和细胞凋亡情况的数据采用t检验进行统计学处理.结果 通过光镜和透射电镜观察发现,Flap-free Epi-LASIK术后第1天有1层新生角膜上皮覆盖切削区域,以后逐层愈合.Epi-LASIK术后第1天角膜上皮基底膜与基质贴附较为紧密,但是在第2天可以看到有角膜上皮瓣水肿发生.术后4 d Flap-free Epi-LASIK角膜基质细胞数量分别为(33.85±3.39)个,多于Epi-LASIK组(t=-2.315,P<0.05).术后2 d、4 d组Flap-free Epi-LASIK角膜基质bFGF表达量分别为101.75±8.07和110.56±9.00,高于Epi-LASIK(t=-2.339,-2.396;P<0.05).术后2 d、4 d组Flap-free Epi-LASIK基质细胞凋亡数量也少于Epi-LASIK(t=3.332,2.989;P<0.05).结论 由于Flap-free Epi-LASIK特定的上皮去除方式导致了特定的上皮愈合方式,有利于减少术后刺激症状及角膜组织的正常修复.     

聚乙烯醇（PVA）水凝胶填充兔玻璃体腔的安全性及有效性研究

目的　评价30 g·L^-1聚乙烯醇（polyvinyl alcohol,PVA）水凝胶在兔玻璃体腔内长期填充的安全性与有效性。方法　将新西兰白兔12只随机分为2组:PVA水凝胶组（PVA组）6只、BSS组6只。2组兔右眼行三通道玻璃体切割术,切除玻璃体后分别填充PVA水凝胶和BSS溶液。术后行裂隙灯、眼底镜、眼压、B超和眼底照相检查;术后90 d、180 d行视网膜电流图（electroretinogram,ERG）检查,同时处死兔并摘出眼球,收集眼内PVA水凝胶后行流变学检查,眼球送病理学检查。结果　至观察终期PVA组与BSS组术眼的角膜、前房等均无明显异常;PVA组有2眼并发白内障、BSS组有1眼并发白内障,2组术眼均未见玻璃体积血、混浊、增殖,视网膜脱离,脉络膜脱离等并发症出现。眼压情况:术前及术后3 d、7 d、14 d、30 d、60 d、90 d和180 d,两组间各时间点眼压比较差异均无统计学意义（均为P>0.05）。ERG检查提示2组术眼SkotERG和PhotERG的a波、b波峰值与术前相比,差异均无统计学意义（均为P>0.05）,两组间比较差异亦均无统计学意义（均为P>0.05）。眼球固定切片和HE染色,光镜下显示:2组术眼视网膜全层结构完整,内丛状层和外丛状层连续,内、外核层细胞排列整齐,视网膜全层细胞未见明显炎症、变性、坏死等改变。电镜下观察显示:术后90 d视网膜色素上皮细胞线粒体轻度水肿、结构欠清,周围有PVA高分子物附着;而术后180 d线粒体细胞水肿明显加重、结构更加模糊。PVA水凝胶在术后90 d玻璃体腔内仍填充较饱满,未见明显降解,黏弹性能未见明显改变,而在术后180 d玻璃体腔内的PVA水凝胶水样物增多,出现明显降解,黏弹性能显著降低。结论　30 g·L^-1PVA水凝胶在体内有良好的生物相容性和视网膜支撑功能,但长期填充后容易被降解。     

Implantation of a Keratoprosthesis of Novel Design in Rabbits

Purpose To evaluate a keratoprosthesis, implanted by penetrating keratoplasty, in rabbits.Methods We implanted our keratoprosthesis (optics and flange portions of polymethylmethacrylate and a polyurethane skirt with micropores) into 14 eyes of 14 rabbits. In four eyes, we evaluated histologically the junction between the keratoprosthesis and host cornea. Long-term keratoprosthesis survival was evaluated in ten eyes by slit-lamp biomicroscopy.Results The histological study showed good approximation of the keratoprosthesis to the host cornea in the junction area, with overlying superficial corneal stroma on the skirt, keratocyte and collagen fiber ingrowth into the micropores, and partial migration of epithelial cells onto the skirt. However, in the long-term survival study, eight out of ten eyes developed acute suture-related inflammation, considered to be from bacterial infection, requiring enucleation 30 ± 18 weeks after implantation. The remaining two eyes have survived for 70 and 76 weeks.Conclusions Our keratoprosthesis was well tolerated in the short term. However, further modifications are necessary to avoid corneal infection. Jpn J Ophthalmol 2004;48:448–453 © Japanese Ophthalmological Society 2004     

AlphaCor人工角膜移植治疗兔角膜碱烧伤

目的评价AlphaCor人工角膜移植对兔角膜碱烧伤的治疗效果。方法用1mol/LNaOH烧伤兔左眼建立角膜碱烧伤模型,选择角膜白斑、角膜缘新生血管〉2个象限的5只兔眼行人工角膜移植术。AlphaCor人工角膜移植手术分2期进行：Ⅰ期手术,将AlphaCor人工角膜植入角膜板层间;Ⅱ期手术,暴露人工角膜光学区。术后观察人工角膜、受体角膜及眼前节情况。结果碱烧伤后2～6周形成带新生血管的角膜白斑。Ⅰ期术后5例人工角膜均在位,2例人工角膜出现白色沉积物,其中1例并发角膜浅层基质溶解,另3例无并发症发生。Ⅱ期手术中麻醉死亡1例,其余术后人工角膜均在位,1例术后6周发生角膜感染、穿孔,另3例术后4～6周发生人工角膜前膜增生,未见其他并发症发生。结论 AlphaCor人工角膜移植治疗兔角膜碱烧伤具有良好的生物相容性,效果较好。     

Development and clinical assessment of an artificial cornea

Keratoprosthesis research has been a gradual, rather fragmentary process with advances being made by isolated groups of researchers. This has arisen partly because of poor funding in the area; research groups which have achieved commercial support have often had constraints upon the full disclosure of their findings. Despite these difficulties there has been real progress over the last decade by several independent groups. This article concentrates upon our own development of a hydrogel core-and-skirt keratoprosthesis, the Chirila KPro, in order to illustrate the scientific and clinical problems common to keratoprosthesis research. Pilot data from a clinical trial is presented and the priorities for future research are discussed.     

A polyvinyl alcohol (PVA) hydrogel as a soft contact lens material

A transparent polyvinyl alcohol (PVA) hydrogel was prepared from a PVA solution in a mixed solvent consisting of water and a water miscible organic solvent by cooling. The physical properties were evaluated in comparison with commercially available soft contact lens materials, such as polyhydroxyethyl methacrylate (PHEMA) and copolymers of methyl methacrylate (MMA) and N-vinyl pyrrolidone (VP). The PVA hydrogel showed higher tensile strength and elongation at break than the other materials, while it had high water content and oxygen permeability the latter being comparable to those of PMMA/VP copolymers. The protein adsorption of the PVA hydrogel was much less than those of the other materials. The PVA hydrogel soft contact lenses were applied on rabbit eyes for 12 weeks. The influence on the cornea was studied by biomicroscopy, ultrasonic corneal pachymetry and histopathological examination. These examinations revealed no abnormal findings in the cornea. These results suggest that the PVA hydrogel may be promising as a new soft contact lens material.     

Evaluation of polyvinyl alcohol hydrogel as a soft contact lens material

We prepared a transparent polyvinyl alcohol (PVA) hydrogel from a PVA solution in a mixed solvent consisting of water and a water-miscible organic solvent by cooling. The physical properties of the hydrogel were evaluated in various mixed solvents and compared with those of commercially available soft contact lens materials, such as polyhydroxyethyl methacrylate (PHEMA) and copolymers of methylmethycrylate (MMA) and N-vinyl pyrrolidone (N-VP). The PVA hydrogel showed higher tensile strength and elongation before breaking than did the other materials. Also, the PVA hydrogel was comparable in its high water content and its oxygen permeability with the MMA/VP copolymers. The protein adsorption of the PVA hydrogel was much lower than that of the other materials. Soft contact lenses of PVA hydrogel were applied to rabbit eyes for 12 weeks. The effects of the lenses on the cornea were studied by biomicroscopy, ultrasonic pachymetry, and histopathologic examination. No abnormal findings were noted, suggesting that the PVA hydrogel may be promising as a new material for use in soft contact lenses.The developments discussed in this paper were presented in part at the Annual Meeting of the Association for Research in Vision and Ophthalmology, Sarasota, May 1988     

聚乙烯醇水凝胶模拟自然玻璃体的实验研究

目的　筛选与自然玻璃体性能相似的聚乙烯醇［poly（vinyl alcohol）,PVA］水凝胶,为探索寻找新的玻璃体替代物提供依据。方法　采用γ-射线（Co⁶⁰）辐照交联得到1%PVA水凝胶、3%PVA水凝胶、7%PVA水凝胶。通过检测PVA水凝胶的物理光学性能（比重、含水率、透光率、屈光率、pH值、溶胀性能）和流变性能及细胞毒性,筛选与自然玻璃体性能相似的PVA水凝胶。结果　（1）物理光学性能:1%PVA水凝胶的含水率、屈光指数、透光率、pH值、比重分别为98.90%、1.335 5、94.80%、7.22、1003.9 g·L^-1;3%PVA水凝胶的各指标分别为98.10%、1.336 1、93.20%、7.25、1014.4 g·L^-1;7%PVA水凝胶的各指标分别为93.50%、1.342 5、88.20%、7.41、1114.7 g·L^-1,3%PVA和1%PVA水凝胶与自然玻璃体有相似的光学物理性能。（2）流变性能:三种浓度PVA水凝胶储存模量（G′）均大于损耗模量（G″）,表明三种物质均为有黏弹性能的凝胶体,且其弹性性能大于黏性性能。1%PVA:G′、G″分别为（3.2±1.1）Pa、（0.8±0.5）Pa;3%PVA:G′、G″分别为（6.1±1.3）Pa、（1.3±0.9）Pa;7%PVA:G′、G″分别为（106.5±18.6）Pa、（18.3±12.8）Pa。在顺应性方面,7% PVA＞3% PVA＞1% PVA;在蠕变方面,3% PVA＞7% PVA＞1% PVA。（3）细胞毒性:MTT比色实验结果显示细胞在1%PVA、3%PVA、7%PVA浸泡液中培养72 h后,各组间吸光度（A值）值比较差异均无统计学意义（均为P>0.05）,表明三种水凝胶均无明显细胞毒性,拥有良好的生物相容性。结论　3%PVA水凝胶具有与自然玻璃体相似的光学、物理和流变性能,拥有良好的生物相容性,能很好地模拟自然玻璃体的性能。     

Clinical results of implantation of the Chirila keratoprosthesis in rabbits

AIMS/BACKGROUND—An ideal keratoprosthesis (KPro) would closely resemble a donor corneal button in terms of its surgical handling, optics, and capacity to heal with host tissue in order to avoid many of the complications associated with the KPros which are currently in clinical use. This study was carried out to assess the long term clinical outcomes on implantation of the core and skirt poly(2-hydroxyethyl methacrylate) KPro in animals.
METHODS—20 KPros were made and implanted as full thickness corneal replacements into rabbits and followed for up to 21 months to date.
RESULTS—80% of the prostheses have been retained, with a low incidence of complications such as cataract, glaucoma, and retroprosthetic membrane formation which are frequently associated with KPro surgery.
CONCLUSIONS—KPros of this type may offer promise in the treatment of patients for whom penetrating keratoplasty with donor material carries a poor prognosis. Refinement of the KPro and further animal trials, including implantation into abnormal corneas, are however mandatory before human implantation could be planned.

Keywords: complications; keratoprosthesis; optics; PHEMA     

国产化人工角膜植入兔眼的稳定性评估

目的 评价国产化人工角膜在兔眼角膜中的中长期稳定性.方法 实验研究.采用长耳大白兔10只,均选右眼作为国产化Moroz改良型永久性人工角膜植入眼,左眼为对照眼.手术分两期完成,一期手术用第三眼睑(软骨组织与人耳软骨有类似效果)加固角膜前层,联合自体结膜遮盖植入人工角膜支架;3个月后进行二期手术,植人人工角膜镜柱.全部手术完成后观察6个月以上.术后抗生素滴眼预防感染,定期观察,照相记录.最终行眼组织病理学检查.并与左眼进行对照.结果 除1只兔在二期术中因麻醉意外死亡外,9只兔均顺利完成手术和术后观察,术后各观察时间点人工角膜均在位,眼表血管化良好,未发生角膜组织融解、房水渗漏、高眼压、感染等严重并发症.组织病理学检查显示:加固的软骨组织均在位,人工角膜支架与周围组织紧密结合,有较活跃的纤维组织增生包绕,角膜炎症反应很轻.对侧眼无异常.结论 国产化人工角膜具有良好的生物相容性和中长期在位稳定性,用耳软骨加固和自体结膜遮盖有助于提高人工角膜稳定性.     

Implantation of Iakymenko keratoprosthesis in patients with severe ocular injury

AIM: To present the results of implantation of Iakymenko keratoprosthesis in five patients with vascularized corneal leukoma caused by severe ocular injury. METHODS: Iakymenko keratoprosthesis was implanted into 5 eyes of 5 patients: 4 patients were suffered from chemical burns and 1 patient from explosive injury. The preoperative visual acuity ranged from light perception to hand motion. The implantation surgery was composed of two-stage procedures. The follow-up period was from 9 months to 11 years. The outcome measures were visual acuity, retention, and complications of the keratoprosthesis. RESULTS: Vision improvements were achieved in most patients. All keratoprosthesis were retained within the follow-up period. Corneal melting occurred in one patient and fibrous closure in another patient, both of which were successfully treated. Retinal detachment occurred in one patient after surgery. CONCLUSION: Iakymenko keratoprosthesis seems to be a promising alternative for the patients with severe corneal injury, but further investigation is needed to evaluate the role of Iakymenko keratoprosthesis.