人工晶体表面细胞学反应实验研究

目的观察兔眼后房型人工晶体植人术后人工晶体表面细胞学反应的病变特征及规律，探讨术后眼内炎症反应的发生机理。方法９只青紫蓝兔分为３组。后房型人工晶体植人术后１、７、１４天摘除人工晶体，行光镜和扫描电镜检查，计数炎性细胞数，采用ＳＡＳ软件包，对统计资料做方差分析。结果术后人工晶休表面有明显的炎性细胞；描述了巨噬细胞演变为上皮样细胞、纤维母细胞样细胞和成纤维细胞的过程；首先发现纤维母细胞佯细胞、上皮样细胞与巨噬细胞胞浆内均含有吞噬颗粒，结论推测人工晶体表面的巨噬细胞、纤维母细胞样细胞和上皮详细胞具有效强的吞噬能力，人工晶体表面存在的淋巴细胞群、巨噬细胞和嗜酸性粒细胞提示对人工晶体所在抗原的兔疫反应。     

Experimental intraocular lens implantation in the rabbit eye and in the mouse peritoneal space. Part II: Morphological stages of the macrophage on the implanted lens surface

Macrophages appearing on implanted intraocular lenses (IOLs) in the rabbit eye and in the mouse peritoneal space were observed using Wolter's implant cytology staining and scanning and transmission electron microscopy. In response to the implanted IOL, macrophages in the mouse peritoneal space displayed an activated form with marked ruffles on the surface. They were attached to the IOL with a broad base (sessile macrophage). The macrophages metamorphosed gradually to the flat shape of so-called epithelioid cells with many processes. They showed a tendency to fuse together or become more flat by extending the cytoplasmic lamellipodia and finally disappeared, leaving a thin membrane or a fibrous matrix. Phagocytic activity of macrophages and related cells was also observed. However, those observed on the IOL implanted in the rabbit eye showed less surface structure and appeared to adhere weakly to the IOL.     

Effect of intraocular lens implantation on combined extracapsular cataract extraction with trabeculectomy: a comparative study.

In an attempt to assess the effect of posterior chamber intraocular lens (IOL) implantation on the outcome of combined extracapsular cataract extraction (ECCE) and trabeculectomy we compared 23 eyes subjected to ECCE and trabeculectomy with 23 eyes subjected to a triple procedure-that is, with the addition of IOL implantation. The results showed that IOL implantation did not have a detrimental effect on postoperative IOP reduction, gain in visual acuity, or needs for antiglaucoma medication. The incidence of anterior chamber reactions consisting of the development of posterior synechiae and fibrin formation was significantly higher when IOL had been implanted. However, the fibrin was generally absorbed within 14 days and the posterior synechiae did not occlude the visual axis. We conclude that IOL implantation should be included in these combined operations with the object of rehabilitating visual function.     

Effects of surface modification of intraocular lenses on foreign body reaction

PURPOSE: In order to improve biocompatibility, we investigated the effects of surface modification by 2-methacryloyloxyethyl phosphorylcholine (MPC) on the foreign body reaction of intraocular lens (IOLs). MATERIALS AND METHODS: Materials of the IOLs were polymethylmethacrylate, hydrophobic acryl, and MPC surface-modified hydrophobic IOLs (MPC modified acryl). In an in vitro study, cultured macrophages sampled from mouse intra-abdominal exudate were cultured on a plate for each IOL material. The cell density and morphology of attached cells on the IOL materials were investigated. In an in vivo study, each IOL material was implanted in the peritoneal space of mice and foreign body reaction was investigated with a light microscope and a scanning electron microscope. RESULTS: In the in vitro study, the cells on the MPC modified acryl IOL material were remarkably fewer than those on the plates of the other two IOL materials. Regarding the implanted IOL matrevials, MPC modified acryl IOL material showed more polynuclear giant foreign body cells in the early period than the other two IOL materials. CONCLUSION: MPC surface modification can reduce the foreign body reaction of IOLs and has the potential to improve biocompatibility of IOL materials.     

Immunohistochemical study of cellular response on the intraocular lens surface

This immunohistochemical study was conducted to observe the cellular proliferation on the surface of an intraocular lens (IOL) implanted in the rabbit eye. One week after extracapsular lens extraction followed by posterior chamber lens implantation, the IOL was removed and examined by an indirect immunohistochemical method using anti-macrophage antiserum. Macrophage immunoreactivities were observed on the small round cells, the middle-sized oval cells, the foreign-body giant cells and the fibroblast-like cells attached to the surface of the IOL. Most of the cellular components on the implanted IOL seemed to be macrophages.     

Material properties of various intraocular lenses in an experimental study

INTRODUCTION: With the recent introduction of small-incision cataract surgery, requirements for intraocular lens (IOL) flexibility, strength and hydrophilicity have rapidly evolved. The IOL surface, however, remains a critical factor influencing uveal biocompatibility. PURPOSE: To objectively quantify factors of material properties of various IOLs using contact angle measurements, differential scanning calorimetry, dynamic-mechanical measurements and scanning electron microscopy. MATERIAL AND METHODS: In our study, 17 currently available IOLs were investigated using contact angle measurements to assess hydrophilicity and biocompatibility, as well as differential scanning calorimetry for the estimation of glass transition temperature. Mechanical capacity and flexibility were investigated using dynamic-mechanical measurements. Additional analysis of the IOL surface was performed using scanning electron microscopy. RESULTS: The contact angle measurements of the studied IOLs revealed similar values within each group. The silicone IOLs had values between 106 and 119 degrees. The PMMA IOLs were found to have a narrower range of values, between 73.2 and 75.5 degrees. Lenses made of hydrogel had values between 59.2 and 69.1 degrees. The heparin-modified surface showed the lowest contact angle of 56.5 degrees. The glass transition temperature was determined by dynamic differential scanning calorimetry. The resulting values were between 118.8 and 113.5 degrees C for PMMA IOLs, 15.5 and 14.0 degrees C for acrylic IOLs, and -91.7 and -119.6 degrees C for silicone IOLs. The dynamic-mechanical measurements revealed that PMMA lenses manifested characteristics similar to glass, whereas silicone lenses had characteristics similar to rubber. Acrylic lenses were between rubber and glass. Scanning electron microscopy revealed smooth dispersion of fibrin on hydrophobic IOLs and a relative lack of fibrin adhesion on hydrophilic materials. CONCLUSION: These results demonstrate that material properties of various IOL materials are consistent within classes of IOL materials. This suggests that the intraoperative and postoperative behavior of an IOL is predictable and related to its composition, thus allowing surgeons to choose IOLs more appropriate for different surgical situations and individual patient characteristics.     

Experimental study of cellular response on the intraocular lens surface in terms of the presence and distribution of fibronectin

An immunohistochemical study was performed to observe cellular proliferation on the surface of implanted intraocular lenses (IOLs) in rabbit eyes. Rabbits were killed 3-28 days postoperatively. The removed IOLs were examined by an immunoperoxidase staining method using anti-fibronectin antibodies. The immunoreactivity for fibronectin was detected in macrophages and multinucleated giant cells attached to the IOL surface. Prominent stains were observed in these cells 1 week after the operation, and staining for fibronectin was less intense in the specimens 2 and 4 weeks after implantation. Fibronectin is produced by macrophages and multinucleated giant cells on the IOL surface, and might play important role in cellular adhesion and motility. Fibronectin immunoreactivity decreased with time and it may be related to cellular activity.     

Fibrin deposits on the surface modified PMMA IOLs

Fibrin reaction and fibrin deposits on the surface of intraocular lens (IOL) after implantation were studied experimentally in vitro and in vivo, using various surface-modified PMMA IOLs. PEO-coated PMMA IOLs and heparinized PEO-coated PMMA IOLs prevented deposition of fibrin. The results suggested these IOLs would be useful to prevent accumulation of fibrin deposits.     

Presence and distribution of fibronectin on the surface of implanted intraocular lenses in rabbits

An immunohistochemical study was performed to observe cellular proliferation on the surface of implanted intraocular lenses (IOLs) in rabbit eyes. Rabbits were killed at intervals of 3 days and 1, 2, and 4 weeks after the operation. The IOLs were removed and examined by an immunoperoxidase staining method using antifibronectin (anti-FN) antibodies. The FN immunoreactivity was detected in macrophages and giant cells attached to the IOL surface. Prominent staining was observed in these cells 1 week after the operation, and staining for FN was less intense in the specimens obtained 2 and 4 weeks after implantation. These findings suggest that FN is produced by macrophages and giant cells on the IOL surface and may play an important role in cellular adhesion and motility. FN immunoreactivity decreased with time, which might be related to cellular activity.     

A comparison of heparin-coated and uncoated intraocular lenses in glaucoma patients undergoing combined cataract extraction and trabeculectomy and in diabetic patients undergoing cataract extraction

The postoperative course of cataract extraction and IOL implantation combined with trabeculectomy in glaucoma patients and of cataract extraction with intraocular lens (IOL) in diabetic patients is more complicated than that of cataract extraction with IOL implantation in otherwise healthy eyes. The main complications are fibrin in the anterior chamber, pigment dispersion, and posterior synechiae. In an attempt to determine whether heparin-coated lenses reduce the rate of these complications, a prospective study was conducted on 19 glaucomatous eyes of 19 patients who underwent a combined procedure of trabeculectomy and extracapsular cataract extraction with IOL and 20 eyes of 20 diabetic patients subjected to extracapsular cataract extraction with IOL. In each category of patients, the early postoperative course in those who received heparin-coated lenses and those who received regular polymethyl methacrylate (PMMA) lenses was compared with respect to the inflammatory reaction, assessed by the amounts of cells and flare, and complications in terms of fibrin, posterior synechiae and pigment dispersion. The results of this preliminary study indicate a slightly higher rate of early postoperative complications with the heparin-coated lenses as compared to PMMA lenses.     

Collagenous deposits on explanted intraocular lenses.

An immunohistochemical study of type I collagen in deposits on the surface of two intraocular lenses (IOLs) explanted from human eyes was conducted. Type I collagen-immunoreactive proteinaceous deposits with cells were found around the haptics of an iris-supported IOL. A few such deposits and what appeared to be macrophages were observed on the optic. A few cells (presumably macrophages and giant cells) were observed on a posterior chamber IOL, whereas proteinaceous deposits that reacted positively to the antibody were not identified. Type I collagen-immunoreactive deposits on the iris-supported IOL were thought to be the products of fibroblastic cells, originating from iris tissue, that attached directly to the haptics and helped stabilize the implant.     

Scanning electron microscope of for endophthalmitis case

PURPOSE: The purpose of this study was to demonstrate the usefulness of the scanning electron microscope in examining the posterior capsule and an intraocular lens (IOL) in an endophthalmitis patient. METHODS: The patient was a 77-year-old man with diabetes mellitus undergoing radiotherapy for prostatic carcinoma, and having a history of esophageal cancer. Phacoemulsification, aspiration and IOL insertion by keratotomy were carried out. The operation was performed without complications. The IOL was a one-piece acrylic type. However, after 24 hours, we diagnosed acute bacterial endophthalmitis, because the patient showed visual loss, high intraocular pressure, fibrin formation, and an increase of cells in the anterior chamber. Vitrectomy to remove the IOL and posterior capsule was carried out on the same day. The removed samples were observed by scanning electron microscope. RESULTS: Enterococcus faecalis was detected in the vitreous and aqueous humor. The bacteria adhered to the optic and haptic surfaces and showed biofilm formation. The traces of the end mill cutting line were recognized beside the haptics. However, the posterior capsule showed no bacterial adhesion but had an unusual shape. CONCLUSIONS: We observed the biofilm formation in an IOL removed from an acute bacterial endophthalmitis case. An IOL may be an important canse of bacterial proliferation and adhesion.     

In vivo implantation of hydrophobic acrylic intraocular lenses with surface modification

OBJECTIVE:To assess the surface properties of modified hydrophobic acrylic intraocular lenses (IOL) implanted in rabbits.;METHODS:The hydrophobic acrylic IOLs were modified with monomer vinyl pyrrolidone by surface modification technique. Phacoemulsification combined with IOL implantation was conducted in 9 rabbits (18 eyes). Postoperative responses were observed by slit-lamp microscope at 3, 7, 15, 30, 90 days after surgery.;RESULTS:During the early stage after IOL implantation, corneal edema and anterior chamber fibrin exudation were observed. The exudate fluid was almost absorbed at the 15th day postoperatively. At 7th day, the anterior chamber exudation in the modification group was significantly less severe than that in non-modification group (P < 0.05). Posterior capsular opacification occurred at 30th day after surgery and was aggravated 90 days later. IOL dislocation was seen in 5 eyes and occlusion of pupil in 3 eyes.;CONCLUSIONS:The hydrophobic acrylic IOLs with surface modification have improved surface properties and higher uveal biocompatibility.     

Biological compatibility of polymethyl methacrylate, hydrophilic acrylic and hydrophobic acrylic intraocular lenses

PURPOSE: Extensive clinical investigations of the biocompatibility of different intraocular lenses (IOLs) have been made in an effort to optimize the outcome of modern cataract surgery. The aim of this study was to add animal eye experimental implantation data regarding cellular reaction on the anterior surface of IOLs. METHODS: Thirteen adult albino rabbits had phacoemulsification/aspiration of the crystalline lens followed by implantation of a posterior chamber IOL in each eye. Three types of IOLs were studied: Hydroview (Bausch and Lomb; n = 7), Acrysof (Alcon, USA; n = 7), and polymethyl methacrylate (PMMA; HOYA, Japan; n = 7). The animals were killed by intravenous pentobarbital 1, 4, or 8 weeks later. The IOLs were explanted and stained with hematoxylin and eosin, and observed under a light microscope. The shape of mouse ascites-induced macrophages on the anterior surface of the three different IOL types (Hydroview, PMMA, and Acrysof) was studied after 24 h of oven culture. RESULTS: Hydrophilic acrylic IOLs showed the highest affinity for lens epithelial cell (LEC) outgrowth, and the lowest and slowest maturation rate reaction of macrophages. PMMA IOLs showed the lowest affinity for LEC outgrowth, and the highest reaction of macrophages. Hydrophobic acrylic IOLs showed intermediate results both regarding LECs and macrophages. CONCLUSIONS: Results suggest that IOL biomaterial properties are the key factor that influences the quantity of monocytes/macrophages as well as the process of their maturation/senescence. LEC outgrowth is influenced both by the biomaterial of IOLs and by the monocyte/macrophage reaction.     

Cellular adhesiveness on implanted lenses in monkeys

Cells are known to adhere to implanted intraocular lenses (IOLs), but the mechanisms of this adhesiveness are not known. We studied cellular adhesiveness on four posterior chamber IOLs that had been implanted into monkey eyes. The animals were killed at 4 and at 7 days after lens implantation. The IOLs were removed and examined by transmission electron microscopy. At 4 days after IOL implantation, macrophages were attached to the IOL surface; at 7 days after implantation, multinucleated giant cells were attached to the IOL surface. These cells had bundles of microfilaments in the subplasmalemmal region of areas of close cell-IOL apposition. These microfilaments may play an important role in the cellular adhesiveness on the surface of implanted IOLs.     

玻璃体腔内套结法固定脱位人工晶状体的效果

目的 采用玻璃体腔内套结法处理脱位至后玻璃体腔内的后房型人工晶状体(IOL),并对手术效果进行观察.方法 回顾性病例研究.对12例IOL脱位至玻璃体腔的患者行玻璃体切除术后玻璃体腔内复位固定后房型IOL,术后随访6～61个月,观察手术前、后患者的视力情况和并发症.结果 12例患者术后最佳矫正视力为0.02～1.0,IOL位置在随访期间无改变.所有病例术后均有不同程度角膜水肿,5例早期眼压偏低,2例出现一过性眼压增高,1例出现前房纤维素性渗出.2例术后发生视网膜脱离,行巩膜外环扎术成功复位.结论 玻璃体腔内IOL固定术无需取出IOL,可以减少对眼球的创伤及切口源性角膜散光,是处理IOL脱位于玻璃体腔简单、有效的方法.     

青光眼白内障联合术植入不同材料人工晶状体效果评价

目的比较青光眼白内障联合术中植入不同材料人工晶状体（IOL）的临床效果。方法回顾性分析行青光眼白内障联合术70例（76眼），其中植入PMMA IOL30例（36眼），硅胶IOL23例（23眼），丙烯酸酯折叠IOL17例（17眼）。对治疗效果进行评价，平均随访期限为10．5月。结果3组间术后眼压和最佳矫正视力差异无统计学意义。前房纤维素样渗出物和IOL表面沉积物发生率，硅胶组高于PMMA组和丙烯酸酯组，但差异无统计学意义。后发障发生率，丙烯酸酯组和硅胶组显著低于PMMA组，差异有统计学意义。结论行青光眼白内障联合术植入PMMA，硅胶与丙烯酸酯IOL在降眼压和提高视力方面具有相似的效果。但硅胶IOL的前房纤维素样渗出物及IOL表面沉积物发生率高于PMMA和丙烯酸酯IOL。丙烯酸酯和硅胶IOL的后发障发生率低于PMMA IOL。     

氟-肝素表面修饰人工晶状体植入兔眼后眼前段超微结构的改变

目的 探讨兔眼植入著者研制的氟-肝素表面修饰人工晶状体的生物相容性.方法 PMMA及氟-肝素修饰人工晶状体各32枚分别植入兔眼内,术后不同时期处死动物,取眼前段标本进行电镜观察.结果 PMMA人工晶状体组角膜实质出现小局灶性水肿,该处胶原纤维松散,有活跃的巨噬细胞及浆细胞,并有角膜内皮细胞粗面内质网中度扩张;睫状体间质细胞浸润较多,胶原纤维不规则,还有成纤维细胞分布其间.而氟-肝素修饰组,则有较轻的反应.结论 氟-肝素修饰人工晶状体略有较好的生物相容性.     

A role of cultured bovine lens epithelial cells in the fibrinolytic system

The release of plasminogen activators (PAs) and plasminogen activator inhibitor (PAI) from cultured bovine lens epithelial cells was investigated, in an attempt to study the effect of lens epithelial cells on the fibrin deposit and fibrinolytic process on the surface of IOL. Cultured bovine lens epithelial cells released tissue plasminogen activator (t-PA) and type 1 plasminogen activator inhibitor (PAI-1). t-PA activity was completely inhibited by PAI-1. These findings suggest that lens epithelial cells cause suppression of fibrinolysis in the anterior chamber of the eye.     

Outcomes of phacoemulsification and in-the-bag intraocular lens implantation in Fuchs' heterochromic iridocyclitis

PURPOSE: To evaluate the visual outcomes and complications of phacoemulsification (PE) and posterior chamber intraocular lens implantation, (PC IOL) in patients with Fuchs heterochromic iridocyclitis (FHIC). SETTING: Private clinic and an academic hospital. METHODS: In this noncomparative interventional case series, existing data for 41 eyes of 40 consecutive patients clinically diagnosed with FHIC and cataract were studied retrospectively. Scleral tunnel PE and in-the-bag IOL implantation were performed in all cases. Preoperative and postoperative visual acuities and intraoperative and postoperative complications were evaluated. RESULTS: Twenty-four male and 16 female patients aged 12 years to 70 (SD) (mean 35 +/- 12 years) were operated on and followed for 17.8 +/- 8.7 months. Preoperatively, best corrected visual acuity (BCVA) was less than 20/40 in all patients, which improved to 20/40 or better after surgery. Twenty-two eyes (53.6%) achieved BCVA of 20/20. The major cause of postoperative visual acuity less than 20/20 was vitreous haze. There were no major intraoperative complications. Postoperatively, mild anterior chamber fibrin reaction occurred in 4 patients (9.7%), IOL deposits occurred in 11 eyes (26.8%), and decentration was observed in 1 eye. During follow-up, 6 eyes (14.6%) developed posterior capsule opacification requiring a neodymium:YAG (Nd:YAG) laser capsulotomy. There was 1 case of clinical cystoid macular edema that resolved with medication. There were no cases of posterior synechias, postoperative glaucoma, or retinal detachment. CONCLUSION: Phacoemulsification with PC IOL implantation is a safe procedure with good visual outcomes in patients with FHIC and cataract.