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At least 19 recordsLinked to original sources

Posterior subcapsular cataracts: histopathologic study of steroid-associated cataracts.

Long-term steroid therapy is associated with production of a posterior subcapsular cataract (PSC). Five steroid-associated cataractous lenses were studied, using light, scanning, and transmission electron microscopy. Anterior, equatorial, and posterior regions were examined. Findings were compared with five age-matched senile PSCs and five nuclear cataractous lenses with no cortical opacities. The posterior polar region of steroid-associated cataractous lenses consists of (1) a superficial zone of liquefaction and (2) a deep zone of segmentally swollen lens fibers. Nucleated lens fibers are present in posterior cortical regions. Cytoplasm at knob and socket junctions had become lucent and plasma membranes were disappearing, leaving empty spaces. Laminated membranous configurations were seen. Although the same basic histopathologic abnormalities were found in steroid-associated cataracts and in nonsteroid senile PSCs, it is their organization and localization that may be the distinguishing characteristics of the steroid-associated cataract.

Adrenal Cortex Hormones

[Utilization of the vitreophage in cataract surgery. Juvenile and traumatic cataract, postcataract membranes].

15 cases of congenital and juvenile cataract have been operated on utilizing the vitreophage of Klöti. In 3 instances posttraumatic cataracts have been removed, in two cases a cataracta complicata, in 9 cases after-cataractous membranes. Serious complications have not been encountered in any of our cases. One patients with congenital cataract and two probands with cataracta complicata developed postoperatively considerable flare in the anterior chamber and vitreous body, possibly the result of a phacolytic reaction. Excision of thick, inelastic after cataractous membranes proved to be difficult at times. The advantage of lensectomy lies in the possiblity of removal at the same sitting of opaque vitreous structures which had become visible during surgery.

Cataract

Cataract--webbed Peromyscus. I. Genetics of cataract in P. maniculatus.

Cataract--webbed (cw) in the deer mouse (Peromyscus maniculatus) is a recessive mutant that is manifested by syndactyly (involving soft tissues) and eye defects including cataract. Within cw/cw mice, the age at which cataract first appears is genetically controlled. Evidence for the activity of genetic modifiers is the early appearance of cataracts in the offspring of parents that developed cataracts at early ages.

Animals

Cell mediated immunity in relation to cataract and cataract surgery.

Two groups of patients suffering from cataract were investigated by the lymphocyte stimulation test. One group was tested before and the other after cataract surgery. Human (total) lens crystallins and bovine alpha crystallin were used as the antigens. Lymphocytes of healthy persons showed practically no positive stimulation with either antigen. Of the patients tested before operation 38% reacted positively with lens crystallins and 15% with alpha crystallin. This difference in sensitisation suggests a leakage of lenticular antigens other than alpha crystallin out of the lens during cataract progression. Extracapsular lens extraction caused an increase in the number of patients reacting positively with lens crystallins and alpha crystallin as compared to patients not operated upon. Intracapsular lens extraction on the other hand resulted in less sensitisation to lens crystallins as compared to patients not operated upon.

Adult

Ant-egg cataract. A study of a family with dominantly inherited congenital (ant-egg) cataract, including a histological examination of the formed elements.

A family with "ant-egg" cataract in three generations is described. The cataract is congenital, probably of autosomal dominant inheritance. Light microscopy of the ant-eggs showed that they are made up of a peripheral zone of lens material and a large almost homogenous centre. Element analysis by X-ray spectrophotometry showed a high content of calcium and phosphorus in the centre. The cataract has been easy to operate on and the postoperative visual results have been good.

Calcium

Integrative multi-omics quantitative trait loci prioritize CASP7 as a candidate protective gene for cataract.

Cataracts are the leading cause of vision loss worldwide. Despite surgery being the only effective treatment, its economic burden highlights the necessity of exploring the pathogenesis of cataracts. In this study, we analyzed 4 large-scale GWAS (genome-wide association study) datasets for cataracts and performed SMR analysis along with heterogeneity in dependent instruments (HEIDI) testing to explore the effects of methylation, expression, and protein QTLs on cataracts. We further validated shared genetic variants through COLOC analysis. Additionally, we searched datasets related to cataracts from the Gene Expression Omnibus (GEO) database for differentially expressed genes (DEGs) and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses. By integrating summary-based Mendelian randomization (SMR) results with bioinformatics findings, CASP7 showed a consistent protective-direction association with cataract risk (mQTL: OR [95% CI] = 0.959 [0.941-0.977], FDR-adjusted P = .039; eQTL: OR [95% CI] = 0.897 [0.860-0.937], FDR-adjusted P = .0046; pQTL: OR [95% CI] = 0.597 [0.483-0.738], FDR-adjusted P = .00083). GEO-based analyses provided transcriptomic support for CASP7 involvement in cataract-related lens biology. These findings prioritize CASP7 as a genetically supported candidate protective gene associated with cataract risk. Because this study is based on public summary-level and transcriptomic datasets, the results should be interpreted cautiously and require functional validation in human lens-relevant systems.

Quantitative Trait Loci

Causes of enucleation following cataract surgery.

Between the years 1962 and 1976 85 eyes which had undergone cataract surgery were accessioned to the Ophthalmic Pathology Laboratory of the Helsinki University Eye Hospital. The specimens were submitted from the various eye departments of the country. Of these 8k eyes nine had been enucleated within 2 months after surgery while in 64 cases the enucleation had been performed more than 12 months after surgery. 40 eyes had had an attempted operation for senile cataract, 30 eyes for traumatic cataract while the remaining cases were congenital cataract cases or cataracts in pre-existing glaucomatous or chronic uveitis eyes. Most frequent causes for the loss of the eyes were related to incomplete or abnormal healing of the operative wound such as epithelial down-growth and closure of the chamber angle with extensive anterior synechiae leading to absolute glaucoma. It is noteworthy that all cases of epithelial downgrowth were derived from the beginning of the observation period. No new cases were obtained after 1969. Other important causes were purulent endophthalmitis and retinal detachment. Haemosiderosis was a prominent cause in the group with traumatic cataract. A careful histopathological analysis of eyes enucleated after cataract surgery is mandatory as it is from the complications we learn most in cataract surgery.

Aged

Globular bodies: a primary cause of the opacity in senile and diabetic posterior cortical subcapsular cataracts?

We examined 9 cataracts from maturity onset diabetics and 4 senile posterior subcapsular cataracts by scanning electron microscopy, transmission electron microscopy, immunofluorescence for crystallin proteins and actin, histochemical methods and x-ray diffraction. The cataractous regions contained spherical globules up to 20 mu in diameter, often in a fibrous matrix. Some were extracellular Morgagnian globules, apparently formed by blebbing from the cell surface; others appeared to have been formed intracellularly. The area of globular degeneration was usually 300 mu deep, but had deeper fusiform extensions. Morphological changes in the cell cytoplasm varied according to their depth in the cataract. Electron microscopy showed intracellular and extracellular globules, many of them were bounded by lipid bilayer membranes. Immunofluorescent staining showed that all the globules contained gamma-crystallin; some contained alpha- and beta-crystallins and actin. All the globules contained higher concentrations of cysteine or cystine than the surrounding lens tissue but they did not react to stains for carbohydrate or calcium. X-ray diffraction studies showed that crystalline calcium salts were absent. Globules and cavities averaged 45% of the total area in cross section. Assuming an area of cataract to be 300 micron thick and that globules 1 mu in diameter scattered, while 2--20 mu in diameter reflected light, we calculated that light passing through such a thickness would be reduced by 65%. Thus the globules could account for most of the opacity of the cataractous area. Presumably the fibrous degeneration of the cells causes enough light scattering to account for the remainder of the reduction. Cataract patients complain of decreased visual acuity, a golden halo around objects, and difficulties when driving while facing oncoming traffic at night. These probably result from light scattering. In our previous experiments, globular bodies containing gamma-crystallin were found in cells grown in tissue culture, and blebs with increased acitn content similar to Morgagnian globules were formed in tissue culture by treating differentiated rat lens cells of stage 2 by cytochalasin D (which impaired microfilament function). These results suggest the possibility of simulating in tissue culture the morphological alterations seen in the cataractous cell.

Aged

Late results of congenital cataract surgery.

Generally speaking, it can be said, when considering all operated bilateral congenital cataracts, that a visual acuity of over 20/100 is found in approximately 50% of patients. In this study, 230 eyes were followed; of these 100 (43%) had an acuity of 20/60 or better and 130 (57%) had 20/100 or less. In conclusion the functional prognosis is better for incomplete cataracts than for total congenital cataracts. The main reason for this is the fact that total cataracts are often associated with cerebroretinal lesions or anomalies. The patient's age at operation and the surgical technique chosen are secondary factors. When considered from the standpoint of visual acuity, the results of congenital cataract surgery are discouraging, at least in the eyes with complete cataract. The visual prognosis could be better for total congenital cataracts if we operate on them at birth or immediately after birth.

Adult

Nonenzymatic glycosylation, sulfhydryl oxidation, and aggregation of lens proteins in experimental sugar cataracts.

The formation of sugar-cataracts has been hypothesized to involve the nonenzymatic glycosylation, sulfhydryl oxidation, and aggregation of lens proteins. Cataractous lenses of diabetic and galactosemic rats were analyzed for glycosylated lysine residues in crystallins. A five- and a ten-fold increase in glycosylated lysine residues was measured in galactose and diabetic cataracts, respectively. The modification was predominant in the insoluble fraction of the lens homogenate. The proteins were further examined for the presence of disulfide bonds and high molecular weight aggregates. After careful disruption of the lens in a nitrogen environment, a cloudy solution was obtained from cataractous lenses whereas a clear solution was obtained from normal lenses. The absorbance at 550 nm of the solution of both the galactosemic and the diabetic cataracts could be decreased by approximately 50% with the addition of dithioerythritol (50 mM). The presence of high molecular weight aggregates was ascertained by sucrose gradient centrifugation and gel filtration chromatography. The proteins were heterogenous in size and showed a mol wt range of 36 to greater than 176 million daltons. Treatment with dithioerythritol induced a marked decrease in the amount of high molecular weight proteins. These data suggest that sugar cataracts of experimental animals have, in common with human cataracts, the presence of high molecular weight aggregates which are in part linked by disulfide bonds.

Alloxan

Variations of lens thickness in relation to biomicroscopic types of human senile cataract.

The results are reported of 38 ultrasonographic in vivo mensurations of intraindividual differences in axial thickness between a cataractous lens in one eye and a biomicroscopically clear or slightly cataractous lens (incipient deep cortical opacity) in the other. Obviously intumescent cataractous lenses were excluded. In general, the cataractous lens was thinner than the contralateral clear or slightly cataractous lens. Large decreases in lens thickness appeared in lenses with the capsule-near opacities of posterior subcapsular cataract (PSC) + anterior capsular/subcapsular opacity (ACSCO). PSC was more closely correlated to lens thinning than was ACSCO. Nuclear cataract very often occurred in thin lenses, but did not appear to cause lens thinning per se. Deep cortical opacity was not associated with lens thinning. The present results contributed to our argumentation that the decrease in lens thickness is due to a leak of lens material through the "lens membrane" beside a possible cessation of growth of the lens fibres.

Age Factors

Experimental cataract production by high frequency ultrasound.

In vivo animal experiments were performed to study the cataractogenic effects of high-frequency, high-intensity ultrasound. A series of anesthetized rabbits was insonified with quantified exposures of ultrasound using a 9.8 MHz focused ultrasonic beam. Ophthalmoscopic and slit lamp examinations revealed small haze cataracts as the first stage of lenticular damage. Larger exposures produced totally opaque cataracts. These first appeared as fine white threads surrounded by haze cataracts. The intensity-exposure time conjugates required to produce haze cataracts were determined over times ranging from 35 msec to 5 sec. At short times (under 100 msec) a relatively constant amount of energy was needed for cataract production. At longer times, the requried energy progressively increased. This observation, together with the physical appearance of these cataracts, suggests that those lesions are the result of thermal phenomena.

Animals

[Operation on a congenital cataract in a Siberian Tiger].

A cataract operation in a young Siberian tiger is reported. This 5-month-old tiger, presenting with blindness, showed bilateral residual pupillary membranes and anterior polar cataracts combined with nuclear cataracts. After unilateral intracapsular extraction of the lens, the tiger adapted well to the improvement in sight and behaved almost like an animal with normal vision. The animal died 3 months post-operatively from unknown cause. Histological examination of the aphakic eye showed, at the site of operation on the cornea, an intact epithelium with discrete infiltration of the stroma together with low-grade vascularisation. In the eye not treated operatively, both an anterior polar cataract with adherent pupillary membrane strands and a central cataract were seen. Of particular note, when comparing this large wild cat with the domestic cat, was the marked development of the tapetum lucidum (up to 30 cell layers).

Animals

KLF5 promotes proliferation, migration, and autophagy-/EMT‑associated molecular changes in lens epithelial cells via transcriptional activation of THBS1 in traumatic cataract.

PURPOSE: Traumatic cataract is a common blinding eye disease after ocular trauma, and its pathogenesis is closely related to lens epithelial cell dysfunction, while the definite molecular regulatory mechanism between upstream transcription factor and downstream target gene remains poorly clarified. This study aimed to clarify the role and molecular mechanism of the krüppel-like factor 5 (KLF5)/ thrombosponin 1 (THBS1) axis in regulating proliferation, migration, epithelial-mesenchymal transition and autophagy of lens epithelial cells in traumatic cataract, and to explore its potential clinical therapeutic value. METHODS: The GSE295383 dataset in the gene expression omnibus (GEO) database was downloaded, and the differentially expressed genes (DEGs) were screened by linear models for microarray data (limma) package of R language. Combined with Weighted gene co-expression network analysis (WGCNA), the gene co-expression network was constructed and the key modules were screened. Gene ontology (GO), kyoto encyclopedia of genes and genomes (KEGG) and gene set enrichment analysis (GSEA) combined with human transcription factor target (hTFtarget) and JASPAR databases were used to predict the upstream transcription factors of THBS1. Subsequently, SRA01/04 cells were induced with transforming growth factor-beta 2 (TGF-β2) to construct a cataract cell model. RESULTS: THBS1 and KLF5 were highly expressed in LECs exposed to TGF-β2. KLF5 could activate THBS1 transcription by binding to THBS1 promoter - 174 to -165 sites. Knockdown of THBS1 inhibited TGF-β2-induced viability, proliferation, migration, and altered the expression of epithelial-mesenchymal transition (EMT)- and autophagy-related markers in LECs. Knockdown of KLF5 downregulated THBS1 expression and produced a similar inhibitory effect, while overexpression of THBS1 reversed the effect of KLF5 knockdown. CONCLUSIONS: This study demonstrated that KLF5 promoted the proliferation, migration, and EMT‑associated molecular changes of LECs in traumatic cataract through transcriptional activation of THBS1, and regulated the expression of autophagy‑related markers in LECs, suggesting that KLF5/THBS1 axis might be a potential target for the treatment of traumatic cataract.

Cataract

A lipidomic study on the lens epithelial cells of patients with age related cataracts.

Age related cataracts (ARC) represent the main reason for blindness globally. The lens epithelial cells (LECs) participate not only in the metabolism of many substances in the lens but also in maintaining lens transparency. This study used lipidomics to investigate the metabolic differences in LECs of ARC patients with different severity, aiming at identifying potential metabolic biomarkers of ARC. Patients diagnosed with ARC and underwent cataract surgery at Shanghai Tongren Hospital were selected to participate in this study, which were classified as mild ARC group and severe ARC group. During their cataract surgery, anterior lens capsules(LCs) containing LECs were obtained. The lipidomics of LECs were analyzed using the liquid chromatography‑mass spectrometry (LC-MS). Potential pathways of lipids were searched for using databases such as the Kyoto Encyclopedia of Genes and Genomes (KEGG) and MetaboAnalyst platform. In LEC lipids, 26 lipids have been identified as potential biomarkers between mild ARC and severe ARC, with AUC values of 0.67-0.94. The pathway analysis results revealed that the Glycerophospholipid (GPL) metabolism was significantly influenced, indicating that these metabolic markers contribute significantly to regulating this pathway. The LEC metabolic spectrum demonstrates a proficient ability to differentiate between patients with varying levels of cataracts. Herein, we have successfully identified potential metabolic biomarkers and pathways that have proven to be valuable in enhancing our understanding of ARC pathogenesis. The finding has translational value for developing new cataract treatment methods in the future.

Humans