HLA typing from human donor eyes

A method for HLA-ABC and HLA-DR typing of human donor eyes using pigmented retinal epithelial and uveal cells cultured in the presence of human recombinant -interferon is described.This work was generously supported by the Medizinisch-Wissenschaftlichen Fonds des Bürgermeisters der Bundeshauptstadt Wien and the Fonds zur Förderung der Wissenschaftlichen Forschung     

Attempts of tissue typing from human donor eyes

A method for HLA-ABC typing using pigmented retinal epithelial and uveal cells of the donor eye is described and the possible implications for corneal grafting are mentioned.     

Immunohistochemical study of deposits on intraocular lenses explanted from human eyes

Immunohistochemical studies of deposits were carried out on two intraocular lenses (IOLs) explanted from human eyes. One anterior chamber intraocular lens (AC-IOL) was studied using a monoclonal anti-human type I collagen-peptide antibody (C-Ab). One posterior chamber intraocular lens (PC-IOL) was studied using a monoclonal anti-human vimentin antibody (V-Ab). Most of the cells on the AC-IOL contained many melanin granules in the cytoplasm and were thought to be macrophages. They did not show any immunoreactivity to C-Ab. Some spindle-shaped cells and fibrous deposits at the margin of the lens optics showed immunoreactivity to the antibody. These cells were thought to be fibroblasts migrating from the tissue around the IOL, such as the iris. On the PC-IOL, many mononuclear cells and multinucleated giant cells were observed. These cells showed immunoreactivity to vimentin and contained immunostained fibers which were intermediate filaments. They were thought to be either of mesodermal origin or derived from the lens epithelium.     

Cellular reaction on the surface of intraocular lenses removed from human eyes

We studied four angle-supported anterior chamber lenses whose optics and haptics were made of poly(methyl methacrylate). All four lenses had been removed from human eyes because of bullous keratopathy. Using light and electron microscopy, we compared the cellular reaction on the optics, which had been in the anterior chamber, with that on the haptics, which had been in touch with the iris stroma. A typical foreign body granuloma was seen around the haptics, while the optics were free of foreign body reaction.     

Femtosecond laser induced flexibility change of human donor lenses

Background

According to the Helmholtz theory of accommodation the loss of accommodation amplitude is caused by the growing sclerosis of the crystalline lens, whereas the ciliary muscle and the lens capsule are mainly uneffected by age. A permanent treatment method for presbyopia which offers a dynamic accommodation ability is a recent field of study. The concept followed in this paper uses femtosecond laser pulses to potentially overcome the loss of deformation ability of the crystalline lens by creating gliding planes inside the lens tissue to improve its flexibility.

Methods

The aim of the study is to show that the flexibility of human donor lenses can be increased by applying tightly focused near infrared femtosecond laser pulses into the lens tissue. Thereby the tissue is separated by the photodisruption effect. A certain pattern of gliding planes is cut inside the tissue of 41 human donor lenses and the deformation ability of the lenses are compared using the Fisher spinning test before and after laser treatment.

Results

The laser treatment results in an increased deformation ability of the crystalline lens. The lens a-p thickness increases on average by after the treatment. The Fisher spinning test shows an increase of 16% in deformation ability of the lens at a rotational speed of 1620 rpm.

Conclusion

The creation of gliding planes with a fs laser inside the crystalline lens tissue can change the deformation ability of the lens. This might be an indication for a possible method to treat presbyopia in future.     

Effect of bag-in-the-lens implantation on posterior capsule opacification in human donor eyes and rabbit eyes

PURPOSE: To evaluate bag-in-the-lens implantation by studying the feasibility of implanting a new type of intraocular lens (IOL) and the occurrence of posterior capsule opacification (PCO) in human postmortem eyes and in eyes of living rabbits. SETTING: Department of Ophthalmology, University of Antwerp, Belgium, and Netherlands Research Institute of Amsterdam, Amsterdam, The Netherlands. METHODS: The IOL was implanted in 10 postmortem human donor eyes (in vitro study) and in 17 eyes of 10 rabbits (in vivo study). The postmortem capsular bags were cultured for 4 to 6 weeks, and the rabbits were killed 1 to 5 months after implantation. All capsular bags with the bag-in-the-lens were examined by light microscopy and scanning electron microscopy. RESULTS: The IOL design was highly effective in restricting lens epithelial cell (LEC) proliferation in the remaining lens bag in human donor eyes and in rabbit eyes. In eyes in which the capsules were not positioned well within the groove of the IOL, LEC proliferation and PCO occurred. CONCLUSION: Bag-in-the-lens implantation was highly effective in preventing PCO in vitro and in vivo provided the anterior and posterior capsules were secured properly in the peripheral groove of the IOL.     

Evaluation and transplantation of corneas from pseudophakic donor eyes

PURPOSE: To evaluate the quality of corneal donor tissue from pseudophakic eyes for transplantation. METHODS: Only capsular-supported posterior chamber pseudophakia was studied. Forty-five pairs of donor eyes were assessed and evaluated by standard Minnesota Lions Eye Bank (MLEB) protocol. Thirty-three pairs were unilaterally pseudophakic with the unoperated phakic eye used as a control eye. Twelve donors were bilaterally pseudophakic. All corneas were rated for corneal clarity, epithelial defects, stromal edema, Descemet's membrane folding, endothelial cell density (ECD), and cell damage by slit-lamp examination and specular microscopy. If the corneas were not transplanted, the endothelium was vital stained with trypan blue and counterstained with alizarin red S for quantitation, localization, and visualization of cell morphology and damage. RESULTS: Sixty-eight of the 90 corneas in this study did not meet transplantation criteria. A significant difference in ECD (>22%) and in overall corneal rating was found in seven (21%) of 33 pairs of unilateral pseudophakic donors. Fourteen corneal transplants were performed using corneas from the donors in this study. Nine corneas from pseudophakic donor eyes were transplanted, resulting in one primary graft failure reported. CONCLUSION: Corneas from pseudophakic donor eyes may need more extensive evaluation for endothelial viability than is currently required by eye bank standards.     

有晶体眼前房负镜片植入术角膜内皮观察

目的观察有晶体眼植入前房负镜片矫正高度近视术后角膜内皮变化.方法14眼手术,13眼随访24月.术前及术后3月、6月、12月、24月检查角膜内皮密度,内皮形态及有否内皮黑区,对比观察内皮变化,另有3眼RK,4眼未手术眼同样作内皮检查对照.结果13眼术前内皮密度2544±227/mm3,术后3月2341/mm2,术后6月2365/mm2,术后12月2422/mm2,术后24月2358±152/mm2.分别比术前下降8.0%、7.4%、4.8%、7.3%.皮内形态和内皮黑区无变化.随访24月RK组内皮密度下降6.5%,未手术组内皮密度下降1.7%.结论有晶体眼前房镜片植入术矫正高度近视,术后角膜内皮密度有所下降,下降幅度10%左右.但本组病例数较少,随访时间欠长,仅供参考.术后近期内皮密度下降主要与手术有关,而术后远期内皮密度下降可能与眼内慢性炎症、镜片及房水循环有关.     

Light scatter on the surface of AcrySof intraocular lenses: part I. Analysis of lenses retrieved from pseudophakic postmortem human eyes.

BACKGROUND AND OBJECTIVE: To investigate the cause of light scatter measured on the surface of AcrySof intraocular lenses (Alcon Laboratories, Inc., Fort Worth, TX) retrieved from pseudophakic postmortem human eyes. MATERIALS AND METHODS: Ten intraocular lenses (Alcon AcrySofModel MA60BM) were retrieved postmortem and analyzed for light scatter before and after removal of surface-bound biofilms. RESULTS: Six of the 10 lenses exhibited light scatter that was clearly above baseline levels. In these 6 lenses, both peak and average pixel density were reduced by approximately 80% after surface cleaning. CONCLUSION: The current study demonstrates that a coating deposited in vivo on the lens surface is responsible for the light scatter observed when incident light is applied.     

The endopeptidase-resistant protein fraction from human cataractous lenses

With aging and cataract formation, modifications in absorption and fluorescence of the human lens proteins are observed. These changes have been investigated by the examination of the endopeptidase-resistant fraction isolated from human cataractous lenses. This fraction is highly enriched in atypical fluorescence and absorption (i.e. not attributable to tryptophan, tyrosine or phenylalanine). It has a molecular weight of approximately 3000, is enriched in acidic amino acids and has only a 280 nm shoulder in its u.v. spectrum. The material does not contain detectable levels of malondialdehyde or N-formylkynurenine. Upon acid hydrolysis the fluorescence and u.v. spectra remain unchanged with only a minor degree of cleavage observed. Structural studies on some of the cleavage products indicated the presence of oxindolyl alanine and kynurenine. These compounds could result from photo-oxidation of tryptophan.     

表面修饰硅凝胶人工晶状体植入兔眼的生物相容性

目的:表面修饰硅凝胶人工晶状体兔眼植入半年的动态观察。方法:行超声乳化5只兔眼,行超声乳化联合人工晶状体植入术15只兔眼。结果:术后早期炎症反应与手术创伤有关,最常见并发症为人工晶状体移位,修饰人工晶状体引起后囊混浊的程度轻于未修饰人工晶状体。结论:表面修饰提高了硅凝胶人工晶状体的生物相容性。     

Microbial contamination of donor eyes

A total number of 1,516 donor eyes received from various sources during the years 1973-1985 were subjected to the isolation of bacterial contamination. The bacterial cultures taken from the pretreatment eyeball showed culture growth in 366 (24.1%) eyes. Of the 366 positive cultures, 331 (21.8%) were bacterial and 35 (2.3%) were fungal. Amongst the bacterial the major contamination was by staphylococcus aureus and albus and pseudomonas aeruginosa. Gentamicin was found to be the most sensitive antibiotic against a wider group of organisms, the next being chloramphenicol. Thus, treatment of a cadaver eye with a solution of normal saline containing 0.1-0.5 mg/ml of gentamicin is recommended before and after the donor eye is enucleated.     

The spherical aberration of aphakic eyes corrected with intra-ocular lenses

The spherical aberration of eyes corrected with intra-ocular lenses is investigated using a model eye with realistic levels of corneal asphericity. The results indicate that the aberration is intermediate between that of paraxial schematic eyes and real eyes. By using standard optical aberration theory, it is shown that for a plano-convex lens with the curved surface facing the cornea, the aberration is similar to that of normal phakic eyes and therefore probably too low to be of any clinical significance. However, for other lens orientations or designs, the level of aberration is usually higher and may lead to a refractive error varying with pupil size and a loss of acuity with large pupil diameters.     

Surface wave elastometry of the cornea in porcine and human donor eyes

PURPOSE: To introduce a nondestructive technique for characterization of corneal stiffness, determine measurement precision, and investigate comparative stiffness values along central, radial, and circumferential vectors in porcine corneas. The effects of epithelial debridement, relaxing incisions, and crosslink-mediated stiffening on surface wave velocity are also studied. METHODS: A handheld prototype system was used to measure ultrasound surface wave propagation time between two fixed-distance transducers along a ten-position map. Repeatability was assessed with replicate measurements in 6 porcine corneas. In 12 porcine globes with controlled intraocular pressure (IOP), serial measurements were performed before and after epithelial removal, then after 250- and 750-microm-deep relaxing incisions. In human globes with constant intravitreal pressure, central wave velocity and transcorneal IOP measurements were compared before and after collagen cross-linking. RESULTS: Measurement repeatability across all regions was between 2.2% and 8.1%. Epithelial removal resulted in increases in measured stiffness in 67% of eyes, but statistical power was insufficient to detect a systematic change. Wave velocity across a central incision decreased significantly after 250-microm keratotomy (P < .001), but did not undergo a significant further decrease with deeper keratotomy. Meridional stiffness changes consistent with coupling effects were detected after keratotomy. Surface wave velocity and transcorneal IOP measurements increased markedly after collagen cross-linking despite maintenance of a constant IOP. CONCLUSIONS: Handheld corneal elastometry provides a repeatable measure of regional stiffness changes after relaxing incisions and collagen cross-linking in in vitro experiments. Surface wave elastometry allows focal assessment of corneal biomechanical properties that are relevant in refractive surgery, ectatic disease, and glaucoma.     

Postoperative cellular reaction on surface modified intraocular lenses in living human eyes.

Specular microscopy was performed to evaluate the postoperative cellular reaction on surface modified poly(methyl methacrylate) intraocular lenses (IOLs) (Ioptex Research, Inc., model U370) in 40 eyes of 36 patients who had extracapsular cataract extraction with implantation of the surface modified IOLs. The cellular elements observed were fibroblast-like cells, histiocytes, and giant cells. Gray amorphous depositions, part of which were sometimes recognized as interference fringes or interference colors, formed a layer in the center of the optics. These depositions were probably caused by the adsorption from aqueous humor. In subclinical cases, only a few histiocytes and giant cells were recognized in the optic center and the optic periphery was free of the cells during our observation. Within two months of surgery most of the cells had disappeared. In vivo specular microscopy showed no manufacturing defects on the implanted lenses. Our findings suggest that, although there was a postoperative cellular reaction on the surface modified IOLs, they were biocompatible.