正常晶状体及年龄相关性白内障晶状体的超微结构观察

目的：探讨正常晶状体和年龄相关性白内障晶状体的超微结构变化。

方法：采用飞利浦208型透射电镜及日本产JSM-6380LV扫描电镜对3例正常的透明晶状体及5例行白内障囊外摘出的囊膜及晶状体核进行超微结构观察,并进行比较。

结果：透射电镜下白内障上皮细胞与正常组晶状体上皮细胞相比出现大量的异性核,染色质凝集,线粒体肿胀,减少,呈现空泡化; 白内障晶状体核区纤维细胞界限不明显,出现明显溶解、坏死改变。扫描电镜下白内障晶状体皮质纤维细胞失去光滑,晶状体核区纤维细胞表面因挤压而变形,细胞间的连接出现变化。

结论：白内障晶状体中上皮细胞及纤维细胞均发生了超微结构改变,这些变化可能是晶状体混浊的原因之一。     

大鼠钝挫伤白内障模型的建立及其晶状体上皮细胞的超微结构观察

目的 建立钝挫伤白内障大鼠模型及探讨钝挫伤白内障与其晶状体上皮细胞凋亡的关系。方法 50只SD大鼠分成A、B、C、D、E共5组：分别用不同重量的小球，以不同次数连续从不同高度落下打击大鼠的左眼。裂隙灯下观察大鼠品状体的变化，用透射电镜观察晶状体上皮细胞凋亡的超微结构，并与自身对照眼比较。结果 实验开始1周后，5组实验眼的晶状体即出现不同程度的混浊，但是只有D组出现典型的、持续的环状混浊，其晶状体上皮细胞出现明显细胞凋亡的超微结构改变。各组自身对照眼晶状体上皮细胞超微结构无明显改变。结论 20cm高度20g重量的外力持续打击可以使大鼠较快产生典型的、持续的白内障。钝挫伤白内障的发生与晶状体上皮细胞凋亡有关。     

鼠晶状体上皮细胞的体外培养

目的:建立鼠晶状体上皮细胞体外培养的模型。方法:应用组织块贴片法和酶逐步消化法对10~14d的SD大鼠晶状体上皮细胞进行体外培养,在相差显微镜下观察其生长规律。结果:组织块贴片法在加入培养基4~5d后见细胞生长,2wk细胞融合。而酶逐步消化法在加入培养基后7d左右见细胞贴壁,2wk左右见细胞融合。结论:鼠晶状体上皮细胞体外培养较困难,本试验采用酶逐步消化方法和组织块贴片法。成功地建立了鼠晶状体上皮细胞体外培养的模型,为研究后发性白内障发病机制提供了基础。     

先天性后极性白内障超微结构分析及突变基因筛查

目的 探讨一先天性后极性白内障家系晶状体的超微结构改变,并初步筛查其致病基因.方法 收集一常染色体显性遗传性先天性后极性白内障家系资料,对家系成员行眼部检查;在透射电镜下观察晶状体细胞超微结构的改变;选择CRYAB、CRYBA1/A3、CRYBB2、GJA8、CHMP4B、PITX3和EPHA2这7个热点基因进行突变位点筛查.结果 根据家系图分析该家系为垂直遗传,符合单基因常染色体显性遗传特点.裂隙灯显微镜下检查示全部患者晶状体混浊形态完全相同.透射电镜下发现患者前囊面晶状体上皮细胞排列紧密,结构完整,未见特异性病理变化;前皮质晶状体纤维细胞排列紧密,细胞内密度均一一致,但后皮质晶状体纤维细胞内出现斑驳状中高密度异常颗粒沉着.热点基因筛查显示:7个候选基因的外显子及其邻近内含子序列与基因库对照未发现任何突变.结论 本研究将后极性白内障病变定位于后皮质晶状体纤维细胞,排除了前囊面晶状体上皮细胞及前皮质晶状体纤维细胞.此家系携带的遗传突变位点位于尚未见报道的与后极性白内障相关的致病基因上.     

Cytological study of philly mouse cataract

Lenses of Philly mouse, a new congenital cataract animal model derived from Swiss Webster mice, were studied by light and electron microscopy. The lenses developed normally until the first postnatal week. In the beginning of the second postnatal week an early cataractous change was noted due to the appearance of particles in the bow cortex. By the 10th day, distribution of the particles extended mainly to the anterior subcapsular area of the lens cells. Two weeks after birth, enlargement of persisting bow nuclei became prominent. On about the fourth postnatal week, when posterior lens fibers were swollen, degenerating cells and large intercellular spaces were present in the superficial bow cortex. Between five and seven weeks, epithelial cells at the equator became tall, and the number of their mitotic figures was markedly reduced. The lens cells in the posterior cortex became degenerative causing the widening of the posterior suture. At this stage the lenticular nucleus became markedly opaque.These findings suggest that the lens cells of the Philly mouse maintained normal function only until the 7th postnatal day and that the marked loss of differentiating ability causes subsequent cytological changes in various areas of the lens.     

Ultrastructure of anterior lens capsule of intumescent white cataract

Purpose: To analyse the anterior lens capsule thickness and ultrastructure changes of intumescent white cataracts in comparison with nuclear cataracts to prove possible structural reasons for surgical difficulties with the intumescent white cataract. Methods: Anterior lens capsules from 35 eyes with intumescent white and 35 eyes with nuclear cataracts were analysed for their thickness by semithin sections technique and for morphological characteristics by transmission electron microscopy. Results: Capsule thickness was not significantly different in intumescent white compared to nuclear cataracts (mean values 17.5 and 18.5 μm, respectively, p = 0.369). The main morphological features of capsules were extrusions of capsule at the basement membrane‐epithelial border embedding cellular material which were significantly more frequent in intumescent cataracts. Filaments in the basement membrane as well as rarefication of its structure and lamellae were often concomitant with the extrusions. Conclusions: Anterior capsules of white intumescent cataracts do not differ in thickness but have different ultrastructure morphology compared to nuclear cataracts. The extrusions of basement membrane at the basement membrane‐epithelial border towards epithelium, the filamentary inclusions within basement membrane and its rarefication could be the structural causes of tensile weakness and hence additional reason to surgical problems.     

Mutation of Dock5, a member of the guanine exchange factor Dock180 superfamily, in the rupture of lens cataract mouse

Rupture of lens cataract (RLC) in the mouse is a spontaneous mutation inherited by a single autosomal recessive gene mapped on chromosome 14. Fine mapping of the mutant locus revealed a nucleotide deletion of 27-bp at the end of 15th exon of Dock5 (Dedicator of cytokinesis-5), a member of the Dock gene superfamily. Since the deletion occurred in-frame, the RLC-DOCK5 protein had a deletion of 9 amino acids (a.a. 506-514) in the DHR1 (DOCK homology region-1) domain that is essential for DOCK5, a GTP-exchanger for Rac1. Although Dock5 mRNA was intensely expressed equally in mutant and wild-type lenses, DOCK5 protein was hardly detectable in the mutant lens. In contrast, expression of Dock180, another member of Dock subfamily A, was not affected in RLC. Immunohistochemically, DOCK5 was stained intensely in the cytoplasm of the anterior epithelial cells and weakly in lens fiber of the wild type lenses, but little in RLC lens. These observations suggest that the mutation may somehow destabilize DOCK5 protein. We propose to designate the mutant allele of rlc as Dock5rlc. Relevance of the signaling pathway involving DOCK5-RAC1 in maintenance of lens integrity of growing lens is discussed.     

Rncat先天性白内障小鼠的晶状体形态学研究

目的　研究Crygs基因发生突变的rncat先天性白内障小鼠的晶状体组织形态学改变。方法　使用裂隙灯观察rncat白内障小鼠自出生后晶状体混浊的形态改变。并取白内障小鼠的晶状体进行光镜、透射电镜和扫描电镜的检查 ,同时以正常昆明小鼠为对照。结果　发现rncat小鼠白内障是双眼逐渐形成的核心性混浊。病理检查发现晶状体上皮细胞的异常增殖 ,去核纤维化的过程受阻。电镜检查发现晶状体纤维的异常排列和细胞间连接结构的异常。结论　Crygs基因突变可导致rncat白内障小鼠晶状体上皮细胞的变性和晶状体纤维的排列紊乱和细胞间连接的结构改变。     

Delay of cataract development in hereditary cataract UPL rats by disulfiram and aminoguanidine

The UPL rat is a newly developed hereditary cataract model. We previously found that the administration of disulfiram, a dimer of diethyldithiocarbamate that possesses antioxidant activity, and aminoguanidine, which is known to inhibit inducible nitric oxide synthase, inhibits cataract development in selenite-induced cataract rats. In this study, we investigated the anti-cataract effects and mechanism of disulfiram and aminoguanidine on UPL rats. The opacities of UPL rat lenses, as documented by the anterior eye segment analysis system, EAS-1000 (Nidek, Aichi, Japan), increased from 39 days, and apparently mature cataracts were observed at 53 days. Accompanied with the increase in lens opacity, glutathione concentrations in UPL rat lenses decreased. The Na(+) to K(+) and water-insoluble to water-soluble protein ratios, as well as the Ca(2+) contents in UPL rat lenses increased with the development of cataracts. Oral administration of disulfiram and aminoguanidine delayed the lens opacification as well as the changes in glutathione, Na(+) to K(+) ratio, water-insoluble to soluble protein ratio, and Ca(2+) content in UPL rat lenses. The opacity and Ca(2+) content of UPL rat lenses were closely associated. The present study demonstrates that disulfiram and aminoguanidine have potency of the delay of cataract development in UPL rats, probably caused by inhibiting the rise in Ca(2+) levels.     

整合素链激酶在大鼠外伤性白内障模型中的表达

目的:探讨整合素链激酶(integrin-linked kinase,ILK)在大鼠外伤性白内障形成过程中的作用。方法:取15只正常大鼠(体质量250～300g),建立单眼外伤性白内障模型,并随机分为伤后1,3,7d3个时相组,用免疫组化法检测ILK在各组晶状体上皮细胞中的表达。结果:晶状体混浊在外伤后1d即开始出现,并随时间延长而加重。ILK在各外伤组晶状体上皮细胞中均有较强的阳性表达。而未行手术的对照眼ILK表达为阴性。结论:晶状体穿通伤后ILK参与了外伤性白内障形成的病理环节。     

PDGF-AA在大鼠外伤性白内障模型中的表达

目的:研究大鼠单眼外伤性白内障形成过程中,双眼前、后节血小板源性生长因子同二聚体A亚型(PDGF-AA)及其受体(PDGFR-α)的表达。方法:以45只大鼠晶状体穿通伤建立单眼外伤性白内障动物模型,用ELISA法检测伤后不同时相双眼房水中PDGF-AA含量,用免疫组化法检测晶状体上皮细胞及葡萄膜中PDGFR-α的表达,并进行相关的统计学分析。结果:单眼晶状体穿通伤后2wk内,双眼房水中PDGF-AA含量值均成双峰样规律性变化,伤眼组含量值明显高于对侧眼组(P<0.001);伤眼组晶状体上皮及葡萄膜PDGFR-α表达为阳性,对侧眼没有PDGFR-α的表达。结论:晶状体穿通伤后PDGF-AA参与了外伤性白内障形成的病理环节。     

大鼠半乳糖性白内障晶状体上皮细胞的病理变化

目的　探讨半乳糖性白内障大鼠晶状体上皮细胞的改变。方法　２４只ＳＤ雌性大鼠,分为正常对照组和白内障组,每组１２只。白内障组大鼠用半乳糖饲料喂养,正常对照组大鼠用普通颗粒饲料喂养。裂隙灯显微镜下观察大鼠晶状体混浊程度变化,观察至３０ｄ处死大鼠后取晶状体,在光镜和电镜下观察晶状体病理组织和超微结构改变。结果　观察至３０ｄ时,正常对照组大鼠晶状体保持透明,白内障组大鼠９眼（３７．５％）出现均一的皮质性混浊,１５眼（６２．５％）出现核混浊。白内障组光镜下可见晶状体皮质和核部大量纤维细胞水肿、崩解,前囊膜下及后囊膜下出现纤维细胞样的有核细胞堆积;透射电镜下可见晶状体上皮细胞变性、增生并突破晶状体上皮层向浅层皮质移行。结论　半乳糖性白内障不仅有晶状体纤维细胞水肿及结构破坏,还存在晶状体上皮细胞的异常增生、分化和移行。     

Differential synthesis and degradation of protein in the hereditary Philly mouse cataract

Lens protein metabolism was investigated in the Philly mouse between the third and eighth postnatal week. As demonstrated in an accompanying article, the Philly mouse develops a hereditary, osmotic, cataract associated with influx of Na⁺ and loss of K⁺ during this time interval. The contents of β- and γ-crystallin were strikingly reduced in the Philly lens, as judged by sodium dodecyl sulfate (SDS)-urea-polyacrylamide gel electrophoresis and by immunodiffusion. This appeared to be due to proteolysis, since there were negligible amounts of crystallins found in the medium of cultured Philly lenses. α-Crystallin remained in the Philly lens but apparently accumulated discrete polypeptide cleavage products. The incorporation of [³⁵S]methionine into β- and γ-crystallin polypeptides was markedly reduced in the Philly lens. By contrast, the incorporation of [³⁵S]methionine into the α-crystallin and the higher molecular weight non-crystallin polypeptides was as great if not greater, in the Philly lens than in the normal lens. The non-crystallin polypeptides were associated with the 10 000 × g pellet of the homogenate. The present data extend the correlation between alterations in protein metabolism and electrolyte concentrations to this hereditary cataract, and support the idea that selective degradation of crystallins and differential reduction in the synthesis of crystallins are primary causes for the lowered amounts of soluble protein—especially β- and γ-crystallin—found in cataracts associated with ionic imbalances.     

白内障摘除人工晶体植入术后糖尿病性视网膜病变进展的观察

为观察白内障囊外摘除术后糖尿病性视网膜病变的进展，我们对７０例糖尿病患者中的７０眼行白内障囊外摘除人工晶体植入术。术后对术眼及对侧非手术眼进行了观察比较。发现术眼中３８眼（５４．３％）非手术眼中（１５．７％）出现视网膜病变进展。术眼中６６眼（９４％）视力优于术前。但视力结果取决于视网膜病变特别是黄斑病变程度。说明白内障手术加剧糖尿病性视网膜病变，但非禁忌证。早期视网膜光凝可防止病变进展，有助于稳定视力。     

白内障撕囊直径不同对后发性白内障影响的临床研究

目的:观察连续环形撕囊口完全覆盖人工晶状体光学面与连续环形撕囊口完全不覆盖人工晶状体光学面的人工晶状体植入术后后囊膜混浊(posterior capsular opacification,PCO)的情况。方法:随访近5a来施行超声乳化吸出白内障联合人工晶状体植入手术的老年性白内障患者164例196眼,术后观察视力、撕囊口与人工晶状体光学面的关系及PCO等情况,随访12~26(平均16.3)mo。根据Sellman等的PCO分级标准进行分级:I级为没有PCO或极轻微PCO不减少红光反射,也没有珍珠样小体或IOL边缘也没有发现珍珠样小体;Ⅱ级为轻度PCO减少了红光反射,IOL边缘也没有发现珍珠样小体;Ⅲ级为在IOL区域内发现中度纤维化或珍珠样小体,但视轴(中心3mm)是透明的;Ⅳ级为重度纤维化或珍珠样小体并扩展到视轴区,并且严重减少红光反射。术后后囊膜出现Ⅱ,Ⅲ及Ⅳ级统计为临床出现后发性白内障的并发症病例。结果:后发性白内障是现代白内障摘除手术后晚期常见的并发症之一,连续环形撕囊口完全覆盖人工晶状体光学面组120眼中,发生后发性白内障42眼(35.0%)。连续环形撕囊口完全不覆盖人工晶状体光学面组76眼中,发生后发性白内障41眼(53.9%)。两组病例术后在临床后发性白内障发生率上有统计意义(P<0.05)。结论:连续环形撕囊口大小与术后后囊膜的混浊有关。撕囊口完全覆盖人工晶状体光学面能减少后发性白内障发生的几率。     

不同性质眼外伤人工晶体植入的疗效比较：附102例临床报告

１０２例１０３眼外伤白内障在植入后房型人工晶体后，经过平均随访４．０２月（１￣５４月）。术后矫正视力达０．５以上者，在眼内异物伤中占６４．７％，在眼球挫伤中占５９．１％，在眼球穿通中占４４．７％，在眼球爆炸伤中占２７．１％。观察结果表明疗效取决于患眼的受伤程度。     

Alteration of Crystallin Polypeptides in Rat Lenses during the Development of Galactose-induced Cataract

Some striking differences in relative polypeptide abundanceof crystallins were observed in normal and galactose-induced cataractouslenses of rat by means of SDS-PAGE.In the cataractous lenses aprominent band appeared at about 25 kDa and the αA chain increasedmarkedly,whereas the relative amount of the 31 kDa band decreasedsubstantially.These alterations are similar to the changes observed duringthe incubation of young mouse lenses in glucose-free medium.Eye Science1993;9:143-145.     

Lens retrodots and vacuoles and their associations with the prevalence and incidence of age-related cataract

Aim

To assess the prevalence of retrodots and vacuoles and their associations with the prevalence and long-term incidence of age-related cataract in an older Australian cohort.

Methods

Of 3654 baseline participants of the Blue Mountains Eye Study aged 49+ years (1992–1994), 2335 and 1952 were re-examined after 5 and 10 years, respectively. Lens photographs were graded for cataract, retrodots, and vacuoles. Eye-specific data were used to assess the associations between retrodots or vacuoles at baseline and the prevalence and 10-year incidence of nuclear, cortical, and posterior subcapsular (PSC) cataract and cataract surgery.

Results

At baseline, retrodots were present in 142 persons (4%) and vacuoles in 1333 persons (40%). Prevalence of both lens features increased with increasing age (Pfor trend <0.0001). After adjusting for age and gender, vacuoles were associated with prevalent PSC cataract at baseline (odds ratio (OR), 1.60, 95% confidence interval (CI), 1.25–2.05). After adjusting for age, gender, smoking, hypertension, diabetes, education, and use of inhaled/oral steroids, baseline retrodots were associated with an increased incidence of cataract surgery (OR 2.90, 95% CI 1.71–4.91), while 3+ vacuoles at baseline were associated with an increased risk of PSC cataract (OR 3.56, 95% CI 2.13–5.95) and cataract surgery (OR 1.84, 95% CI 1.22–2.77).

Discussion

Lens retrodots and vacuoles were found to be positively associated with 10-year incidence of cataract surgery, and vacuoles associated with PSC cataract, a finding suggestive of shared risk factors or pathogenesis between these two lens features and the development of PSC cataract.