直角边缘囊袋张力环预防兔后囊膜混浊的实验研究

目的:探讨直角边缘囊袋张力环(capsule tension ring,CTR)预防兔后囊膜混浊(posterior capsule opacification,PCO)的作用。方法:新西兰兔20只随机分为两组,进行超声乳化晶状体摘除术后,实验组植入CTR和CraneOV-55C人工晶状体(intraocular lens,IOL),对照组只植入CraneOV-55CIOL。观察术后并发症和PCO情况。术后3mo行光镜和透射电镜检查,观察晶状体后囊膜的形态学变化。结果:术后3mo实验组和对照组都发生了明显的PCO(P>0.05),各组Soemmering环形成程度无统计学差异(P>0.05)。病理学检查发现,两组兔赤道部晶状体上皮细胞增生形成了巨大的Soemmering环,大量晶状体上皮细胞移行至后囊膜。结论:直角边缘CTR未能预防兔PCO的发生,有必要对其进一步改进。     

不同材料直角边缘人工晶状体对后囊膜混浊影响的初步观察

随着超声乳化白内障吸除联合囊袋内折叠型人工晶状体（intraocularlens，IOL）植入术的迅猛发展，术后并发症的防治成为研究的重点，其中后发性白内障，即后囊膜混浊（posterior capsule opacification，PCO）最为常见。目前降低PCO发生的方法主要包括手术和IOL两方面。直角边缘设计对PCO的抑制作用已经得到共识。但由于各个厂商生产工艺的差别，目前市场上各种直角边缘设计的IOL对PCO的影响仍有争议。循证医学的发展为研究不同类型的直角边缘IOL对PCO的作用提供了新思路。本文采用随机自身对照的分析方法，观察不同材料直角边缘IOL植入术后是否对PCO形成的影响有差异。     

术后囊袋弯曲形成在屈光性白内障手术中的意义

屈光性白内障手术时代,术后后囊膜混浊（PCO）以及人工晶状体（IOL）位置异常已成为影响患者视觉质量的重要因素。笔者将从囊袋弯曲角度阐述白内障术后后发性白内障和IOL在囊袋内的稳定性。囊袋弯曲是术后囊袋和IOL锐利边缘贴合形成的屏障结构。完全黏附型囊袋弯曲不仅可以有效减少晶状体上皮细胞的迁移,而且提高IOL稳定性（包括轴向位移、偏心、倾斜及旋转等）。现立足于囊袋弯曲的形成演变过程以及不同分型,阐述了其预防PCO和维持IOL稳定性的机制,为提高白内障患者术后视觉质量提供思路及可行措施。     

不同材料和不同设计的人工晶状体对后囊膜混浊的预防作用比较

目的比较三组不同材料、不同设计的一片式折叠人工晶状体(IOL)在预防后囊膜混浊(PCO)中的作用。方法疏水丙烯酸材料直角边缘组(AcrySof)52眼,亲水丙烯酸材料直角边缘组(ISO)40眼,亲水丙烯酸材料非直角边缘组(Hydroview)32眼,术后12个月扩瞳观察前囊膜混浊(ACO)和PCO的情况并进行统计学分析。结果术后12个月PCO发生率AcrySof组明显低于Hydroview组,ISO组介于二者之间,差异有显著统计学意义(P<0.01);而ACO的发生率三组比较,差异无显著统计学意义(P>0.05)。结论光学边缘锐利的疏水丙烯酸材料折叠式IOL可以更有效地减少PCO的发生。     

阿霉素抑制兔眼晶状体上皮细胞增殖细胞核抗原表达的实验研究

目的 探讨人工晶状体植入术后阿霉素(adriamycin，ADM)抑制兔眼晶状体上皮细胞(rabbit lens epithelial cells，RLEC)增殖的作用及客观评价后囊膜混浊(posteriorcapsule opacification，PCO)的方法。方法 采用兔眼品状体囊外摘出联合人工晶状体植入术的动物模型，术中将携带ADM药物缓释系统植入l5只兔眼晶状体囊袋内。术后观察后囊膜混浊情况；术后第4周，链霉亲和素免疫组化法(strePt—avidin—biotin—enzyme comple，SABC)检测兔眼品状体上皮细胞的增殖细胞核抗原(pro1iferating cell nuclear antigen，PC—NA)的表达。结果 实验组与对照组比较，兔眼晶状体上皮细胞的PCNAP阳性表达下降，2组比较差别具有显著性意义。结论 ADM能有效抑制人工晶状体植入术后RLEC的增殖，免疫组化技术(SABC法)检测RLEC的PCNA的表达，为实验室客观评价PCO提供一种简便有效的方法。     

人工晶状体植入术7年后囊袋膨胀综合征一例

患者 女 82岁 因双眼老年性白内障于1999年2月9日及11日双眼先后进行Phaco＋PC-IOL植入术，术中撕囊口的直径约5．5×5．5mm，应用的黏弹剂为Viscoat（Alcon），PC—IOL材料为Acrylic（Alcon MA60BM，光学部直径6mm），手术过程顺利。术后随访至2004年3月，双眼裸眼视力均为1．2，眼内压多次测量均低于20mmHg。裂隙灯俭查示人下晶状体位置错中，晶状体后囊膜清。患者于2006年6月再次来本院检查双眼，无任何不适主诉。裂隙灯检查发现下方4点至7点及鼻上方9点至12点囊膜呈Elschnig pearl样混浊（图1），撕囊口边缘与人工晶状体前表面360°相贴，人工晶状体位置居中，人工晶状体与晶状体后囊膜之间可见有乳白色液体积聚，液体中悬浮仃微小颗粒（图2）。晶状体后囊膜中央来见有增殖，患者双眼裸眼视力均为1．2。患者诉视力不随体位政变。眼压右眼15．7mmHg；左眼17．7mmHg。     

5-Fu纳米粒涂层人工晶状体抑制兔晶状体后囊膜混浊的实验研究

目的 制备5-Fu纳米粒涂层人工晶状体(IOL)并探讨其对兔晶状体后囊膜混浊的抑制作用的有效性和可行性.方法 通过低能离子束表面氟离子注入技术使5-Fu纳米粒与IOL表面交联黏附形成涂层.取新西兰大白兔40只,随机分为A、B两组,每组20只,对左眼行超声乳化透明晶状体吸出术,对照组为A组,植入普通IOL;实验组为B组,植入5-Fu纳米粒涂层IOL.术后行裂隙灯显微镜、组织病理学及电镜检查.所有数据用SAS统计软件处理,前房闪光和晶状体后囊膜中央视区混浊程度均用Kruskal-Wallis秩和检验进行分析.结果 前房炎性反应:B组的前房闪光轻于A组,差异有统计学意义(x~2=11.245,P=0.024).两组兔眼的前房反应均在术后3 d至1周内缓解.晶状体后囊膜混浊:B组晶状体后囊膜的混浊程度轻于A组,差异有统计学意义(x~2=10.304,P=0.016).光学显微镜行组织病理学检查:A组眼内炎性反应较轻,B组无明显眼内炎性反应表现,A、B两组角巩缘结构及组织均无病理损害.扫描电子显微镜检查:A组见晶状体上皮细胞增生现象,B组未见明显晶状体上皮细胞增生.结论 兔眼透明晶状体超声乳化吸出术后植入5-Fu纳米粒涂层IOL,可有效抑制晶状体后囊膜混浊的发生,眼内毒性较小.     

不同设计人工晶状体植入术后3年后囊膜混浊的研究

目的研究不同材料和不同设计的人工晶状体植入术后3年的后囊膜混浊(posterior capsular opacification,PCO)发生率及PCO形态。方法回顾性研究132眼老年性白内障患者,由同一医生进行超声乳化联合人工晶状体(in-traocular lens,IOL)植入术,根据IOL的不同分为4组:Storz Hydroview H60M组(33眼),Silicone折叠式硅胶IOL组(29眼),AcrySof三片式IOL组(36眼)和聚甲基丙稀酸甲酯(poly-methyl methacrylate,PMMA)组(34眼)。术后3年随访患眼的最佳矫正视力(best corrected visual acuity,BCVA),扩瞳后采集PCO数码图像,分析不同IOL组PCO的形态及PCO发生率。结果各种IOL的PCO形态各异,H60M组和AcrySof组分别有10眼和15眼后囊形成皱折,而Silicone和PMMA组为片状混浊。虽然各组BCVA和BCVA下降率差异没有显著性(P>0.05),但PCO发生率差异有非常显著性,分别是AcySof组5.6%,Silicone组30.3%,H60M组31%和PMMA组55.9%。结论AcrySof疏水丙烯酸酯三片式折叠IOL,有直角边缘设计,术后3年能明显降低PCO的发生。     

两种AcrySof折叠式人工晶体植入后囊膜混浊的临床研究

目的：观察两种设计不同的AcrySof丙烯酸酯折叠式人工晶体(intraocular lens,IOL)对晶状体后囊膜混浊(posterior capsule opacification,PCO)的影响。方法：114例(114只眼)随机分为两组(1)试验组：59例(59眼)，植入一体式AcrySof折叠式IOL。(2)对照组：55例(55眼)，植入三体式AcrySof折叠式IOL。术后半年散大瞳孔观察Soemmering环和PCD情况。结果：瞳孔区PCD，试验组4只眼(6．8％)，混浊多为轻微皱褶。对照组11只限(20％)，试验组PCD明显少于对照组，差异有显著意义(P＜0．05)。两组术后Soemmering环边界均清晰而试验组更加明显，且撵周也形成明显的细胞增殖区。结论：一体式AcrySof折叠IOL具有独特设计的襻使晶状体后囊膜皱褶大为减少，远期PCO明显下降。     

超声乳化术后联合及不联合人工晶状体植入术建立后囊膜混浊兔眼模型的比较

背景后发性白内障（PCO）的防治是目前研究的热点问题之一。建立PCO动物模型常用的方法为超声乳化术后植入或不植入人工晶状体（IOL）,但二者造模的效果评价尚不一致。目的比较兔眼PCO模型建立过程中植入与不植入IOL对PCO的影响。方法选择新西兰白兔20只,用随机数字表法将实验动物分为超声乳化联合IOL植入组和超声乳化不植入IOL组,每组10只兔,两组兔右眼超声乳化手术过程一致,术后共随访3个月,裂隙灯下观察2个组术后晶状体的反应及PCO情况,按OdrichPCO分级系统对术眼PCO情况进行分级。结果术后1～3d,超声乳化联合IOL植入组术眼结膜充血、角膜水肿和房水混浊的严重程度均明显比超声乳化不植入IOL组严重,而术后2周至3个月2个组兔眼的炎性反应均消失;术后1d至3个月,2个组兔术眼的瞳孔直径变化及PCO分级一致。术后2个月,超声乳化不植入IOL组及超声乳化联合IOL植入组兔眼1～3级PCO者分别为8只眼和9只眼,0级PCO者分别为2只眼和1只眼,组间差异无统计学意义（P=0．39）。裂隙灯下检查发现2个组实验眼均于术后1个月开始出现PCO,术后2个月PCO的范围扩大并快速发展,术后3个月形成致密纤维化层。结论采用超声乳化联合IOL植入术建立PCO模型的效果与不植入IOL者相同,但后者术后早期的前房炎性反应较轻,可作为研究PCO的理想动物模型。     

Effect of round-edged acrylic intraocular lenses on preventing posterior capsule opacification

PURPOSE: To clarify the extent to which the adhesiveness of an acrylic material influences the formation of posterior capsule opacification (PCO). SETTING: Jinshikai Medical Foundation, Nishi Eye Hospital, Osaka, Japan. METHODS: Two types of AcrySof(R) intraocular lenses (IOLs) were prepared: round edged and tumbled. The AcrySof with round edges was implanted in 1 eye in a group of 4 rabbits and the tumbled IOL, in 1 eye in a group of 5 rabbits. In both groups, the contralateral eye received a conventional AcrySof with sharp optic edges. A histopathological examination was performed 3 weeks after surgery. RESULTS: With the round-edged AcrySof IOL, no capsular bend formed at the optic edge and abundant lens epithelial cells (LECs) migrated posteriorly. With the sharp-edged AcrySof lens, a sharp capsular bend formed and LEC migration was significantly inhibited. In eyes with a tumbled IOL, a capsular bend was created, but it was less marked than that created by the sharp-edged lens and there was slightly more LEC migration posteriorly. CONCLUSIONS: The AcrySof IOL lost its preventive effect on PCO when the optic was rounded. The effect of the AcrySof lens in preventing PCO is mainly a result of its rectangular, sharp-edged optic design. The acrylic material may play a complementary role by helping create a sharp capsular bend. Capsular bend formation is the key to the PCO preventive effect of an IOL.     

Preventing lens epithelial cell migration using intraocular lenses with sharp rectangular edges

PURPOSE: To compare the preventive effect on posterior capsule opacification (PCO) of an acrylic intraocular lens (IOL) and a silicone IOL, both with sharp rectangular optic edges. SETTING: Jinshikai Medical Foundation, Nishi Eye Hospital, Osaka, Japan. METHODS: After phacoemulsification, an acrylic IOL (AcrySof(R)) was implanted in 1 eye and a silicone IOL (CeeOn 911) in the contralateral eye of 7 rabbits, one of which was omitted from evaluation. RESULTS: The Miyake-Apple view and histopathological findings 3 weeks after surgery revealed that the lens capsule wrapped tightly around the optic edges, conforming to a distinctly sharp bend, with both IOL types in 5 rabbits. Migrating lens epithelial cells (LECs) were inhibited at the site. The AcrySof IOL had a better capsular bend effect in the histological sections, but there was no apparent difference in PCO development between the 2 IOLs. CONCLUSIONS: The CeeOn 911 silicone IOL, with sharp rectangular optic edges, showed an effect on preventing PCO that was similar to that of the AcrySof IOL. When a discontinuous capsular bend is created by an IOL with sharp optic edges, the bend may induce contact inhibition of migrating LECs regardless of the lens' material composition.     

Effect of the optic size of a single-piece acrylic intraocular lens on posterior capsule opacification

PURPOSE: To investigate the effect of the optic size of an intraocular lens (IOL) with sharp optic edges on posterior capsule opacification (PCO). SETTING: Nishi Eye Hospital, Osaka, Japan. METHODS: In 5 rabbits, a single-piece 5.5 mm optic AcrySof IOL (Alcon Laboratories) was implanted in 1 eye and a specially fabricated single-piece 7.0 mm optic AcrySof IOL was implanted in the contralateral eye. Histopathological examinations were performed 3 weeks after surgery. RESULTS: On posterior views, less PCO was noted with the 5.5 mm optic in all rabbits except 1. Histopathological sections demonstrated adhesion of the anterior and posterior capsules between the haptic and optic and the formation of a sharp capsular bend at the posterior optic edge in 3 eyes with the 5.5 mm optic but in no eye with the 7.0 mm optic. Abundant PCO was noted when a sharp capsular bend had not formed. CONCLUSIONS: Capsular adhesion is a prerequisite of capsular-bend formation. The sharp optic edge alone does not provide a substantial barrier when a capsular bend is not formed. Bulky haptics such as those of the single-piece AcrySof and large optics may hamper capsular adhesion and bend formation.     

Effect of surface coating an acrylic intraocular lens with poly(2-methacryloyloxyethyl phosphorylcholine) polymer on lens epithelial cell line behavior

PURPOSE: To evaluate the effect of surface coating of an acrylic intraocular lens (IOL) with poly(2-methacryloyloxyethyl phosphorylcholine) (MPC) on the behavior of the lens epithelial cell (LEC) line, alpha-TN4. SETTING: Department of Ophthalmology, Nihon University School of Medicine, Tokyo, Japan. METHODS: A hydrophobic soft acrylic IOL (AF-1, Hoya) was coated with MPC polymer. A noncoated IOL served as control. An IOL from each group was placed on the membrane of collagen I or IV of the cell culture dish. The alpha-TN4 cells were seeded in the insert. Cell behaviors (ie, cell proliferation and spreading) on IOLs and membranes were observed. Cell migration beneath the IOL optic portion was assayed using a computer software program (POCOman system) for posterior capsule opacification (PCO). Type I or IV collagen is the major matrix component of PCO or native lens capsule. RESULTS: Cell proliferation was more marked on the noncoated IOL than on the coated IOL. Type IV collagen accelerated proliferation more than type I collagen. Cell migration to the area beneath the IOL optic was more prominent in the group with the type I collagen membrane and noncoated IOL than in other groups. CONCLUSION: Coating an acrylic IOL surface with MPC polymer suppressed adhesion and proliferation of LECs, suggesting it improves IOL biocompatibility.     

去整合素kistrin对兔眼晶状体后囊Ⅳ型胶原表达的影响

背景 白内障囊外摘出术后残留的晶状体上皮细胞(LECs)增生是后囊膜胶原产生进而形成后发性白内障的生物学基础,去整合素可与细胞外基质(ECM)竞争结合整合素分子,理论上可以防治后发性白内障的形成,但其具体的作用机制有待进一步研究. 目的 研究去整合素kistrin对兔眼晶状体后囊Ⅳ型胶原表达的影响.方法24只新西兰大白兔按照随机数字表法分为kistrin注射组及生理盐水对照组,每组12只.两组兔均行右眼透明晶状体囊外摘出术,建立兔晶状体后囊膜混浊(PCO)模型,术毕kistrin注射组囊袋内注入80 mg/L kistrin 0.2 ml,生理盐水对照组注入等量生理盐水.术后1、3、5、7、14 d,在裂隙灯下观察实验动物晶状体PCO情况,并按照Odrich法进行分级.术后14d及3个月分别处死两组兔各6只,取出晶状体进行常规石蜡切片,行苏木精-伊红染色,光学显微镜下观察晶状体病理改变;行Masson染色观察晶状体囊袋内胶原纤维增生情况,免疫组织化学法检测兔晶状体后囊Ⅳ型胶原的表达. 结果 术后14 d,生理盐水对照组与kistrin注射组各级PCO的眼数差异无统计学意义(P=0.093),术后1、2、3个月,生理盐水对照组形成2～3级PCO的眼数明显多于kistrin注射组,差异均有统计学意义(P=0.041、0.014、0.022).晶状体组织学检查表明,术后14 d生理盐水对照组LECs层数明显多于kistrin注射组,瞳孔区后囊膜可见单层细胞黏附,kistrin注射组后囊则保持光滑,术后3个月可见生理盐水对照组晶状体后囊的LECs转化为纤维细胞,kistrin注射组较少见.Masson染色显示术后3个月生理盐水对照组晶状体前囊膜撕囊口处与后囊膜之间胶原纤维的蓝绿色染色明显多于kistrin注射组.免疫组织化学染色表明,术后14 d及30 d,生理盐水对照组晶状体后囊膜Ⅳ型胶原的灰度值均明显低于kistrin注射组,差异均有统计学意义(P=0.000、0.001). 结论 去整合素kistrin能够抑制兔眼晶状体囊外摘出术术后晶状体后囊LECs和Ⅳ型胶原增生.     

Comparison of anterior capsule contraction between 5 foldable intraocular lens models

PURPOSE: To compare anterior capsule contraction in cataract patients having implantation of 1 of 5 foldable intraocular lens (IOL) models and evaluate lens epithelial cell (LEC) adhesion to each model. SETTING: Department of Ophthalmology, Dokkyo Medical University, Tochigi, Japan. METHODS: This study comprised 115 patients (126 eyes) without systemic or ocular complications who had phacoemulsification with IOL implantation. The eyes were randomly assigned to receive 1 of the following IOLs: acrylic MA60BM (Alcon), SA60AT (Alcon), AR40e (Advanced Medical Optics), or YA-60BBR (Hoya) or a silicone AQ310NV (Canon). Two weeks and 1, 3, and 6 months postoperatively, the anterior capsule opening area was measured using an anterior segment analysis system (EAS-1000, Nidek) and the percentage of anterior capsule contraction was compared for each postoperative period and IOL. Cell adhesion to each IOL type was evaluated using LECs from albino rabbits. RESULTS: The mean age of the patients was 73.6 years +/- 5.6 (SD). Eyes with the AQ310NV and AR40e IOLs had statistically significantly greater anterior capsule contraction. The rabbit study showed statistically significantly less LEC adhesion on these 2 IOL models. CONCLUSIONS: Anterior capsule contraction was significantly greater with the AQ310NV and AR40e IOLs than with the other IOLs. Results indicate that cell adhesion to the IOL is an important factor in preventing anterior capsule contraction.     

Lens epithelial cell regression on the posterior capsule with different intraocular lens materials

BACKGROUND/AIMS—Posterior capsular opacification (PCO) is caused by proliferation and migration of lens epithelial cells (LECs) across the posterior capsule and is the commonest cause of reduced vision after cataract surgery. The influence of intraocular lens (IOL) material on the process of LEC migration was studied.
METHODS—90 eyes underwent standardised extracapsular surgery, with capsulorhexis and "in the bag" IOL placement. They were randomised to receive a three piece 6 mm lens of PMMA, silicone, or polyacrylic (AcrySof, Alcon, Fort Worth, TX, USA). On days 7, 30, 90, 180, and years 1 and 2 high resolution digitised retroillumination images were taken of the posterior capsule. The presence of LECs was determined at 90 days and 2 years, and their progression or regression was established by serial examination of images.
RESULTS—LECs were seen in 93% of silicone and 97% of PMMA IOLs at 90 days, compared with 46% of polyacrylic (p<0.001). At year 2 LECs were present in all patients with silicone or PMMA lenses, whereas 62% of patients with polyacrylic IOLs had LECs (p<0.001). Of those patients with LECs at day 90 LEC regression occurred in 8% with silicone IOLs and 15% of PMMA cases, compared with 83% of patients with polyacrylic IOLs (p<0.0001).
CONCLUSION—The presence of LECs on the posterior capsule was considerably lower with polyacrylic than PMMA or silicone IOLs and LEC regression occurred more frequently. The lower incidence of LECs and the higher rate of regression may explain why PCO formation appears to be reduced with polyacrylic lenses. This has important clinical implications for the prevention of PCO.

Keywords: lens; cell; implant; posterior capsular opacification     

Selenium functionalized intraocular lenses inhibit posterior capsule opacification in an ex vivo canine lens capsular bag assay

The purpose of this study was to determine the inhibitory effect of selenocystamine coated intraocular lenses (IOLs) on the formation of posterior capsule opacification (PCO) in an ex vivo canine lens capsular bag assay. Selenocystamine was covalently bound to the surface of poly(2-hydroxyethyl methacrylate) (poly(HEMA)) discs. Three groups of canine lens capsules (6 coated IOLs (SeIOLs), 7 non-coated control IOLs and 8 empty capsules) were cultured for 10 days. During the culture period PCO was scored based on visual inspection of the capsules using phase contrast microscopy. On day 10 all the capsules were prepared for light microscopic examination and lens epithelial cells (LECs) were quantified. Proliferating cell nuclear antigen (PCNA), α-smooth muscle actin (α-SMA) and cleaved caspase-3 were examined by immunohistochemistry. Additionally, cell viability assays were performed on LECs cultured in tissue culture medium pre-incubated with either a SeIOL or control IOL. The viability assays demonstrated that no detectable cytotoxic leachables were associated with the functionalized IOLs. The central posterior capsule was free of cells underneath all SeIOLs, although large numbers of LECs populated the capsular periphery. Apoptotic cells were observed underneath the periphery of some SeIOLs. Both the PCO scores and LEC counts of SeIOL containing capsules were significantly lower than those of control group capsules (p < 0.01 and p = 0.0004, respectively).The use of selenium functionalized IOLs resulted in a significant reduction of PCO in this ex vivo model. Binding of selenocystamine to a foldable IOL may provide an effective method to prevent population of the central posterior capsule with LECs.     

Comparison of design of intraocular lens versus the material for PCO prevention

AIM: To evaluate the influence of different intraocular lens(IOL) designs made of PMMA on posterior capsular opacification(PCO) and compare with foldable designs. METHODS: Phacoemulsification and IOL implantation was done in one eye of 24 New Zealand White rabbits, with IOL of two different designs (Square edged or round edge) and two different materials(PMMA or HEMA). After three months, the animals were sacrificed and enucleated. Evaluation of PCO included posterior view, migration of anterior capsular epithelial cells to the posterior capsule following epithelial-mesenchymal transition were assessed by staining the histological sections of posterior capsule by hematoxylin-eosin(HE) and Periodic acid- Schiff (PAS). The IOLs were extracted and stained with HE to evaluate the presence of adherent cells on the lens surface. RESULTS: PCO was highest with round edged rigid lens. There was no significant difference in the PCO between the square edged PMMA and square edged foldable lens. CONCLUSION: It is the design of the IOL not the material that offers protection on PCO formation.