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At least 847 records · Page 47Linked to original sources
PubMed2000

Lens epithelial cell proliferation and cell density in human age-related cataract.

PURPOSE: To discuss the potential effect of the lens epithelial cell proliferation in age-related cataract. METHODS: In vitro cell proliferation was assayed by MTT method to evaluate the lens epithelial cell density, index, and proliferation capacity in normal lens and all kinds of age-related cataract. Capsulotomy specimens from all kinds of patients who underwent cataract phacoemulsification extraction surgery were compared with the lens epithelial specimens from non-cataract lenses of Eye Bank eyes. RESULTS: Lens epithelial cell density of central anterior capsule (LECD) in female normal lens was higher than that in male, LECD in nuclear cataract (> NIII) was higher than that in normal lens, but in the mature cortical cataract, LECD was lower. Mitotic index of three kinds of age-related cataracts in vivo had no statistical difference, neither did cell proliferation capacity of cultivated cells in vitro. CONCLUSION: The individual difference of lens epithelial cell density and proliferation capacity in vivo may be an important underlying cause for senile cataract in the cellular level, especially for nuclear cataract.

Adult↗
PubMed1992

[In vivo autofluorescence. Measurements of human crystalline lenses with cataract and normal findings after excitation with monochromatic light].

In 25 eyes with nuclear cataract, 18 eyes with posterior subcapsular cataract, 25 eyes with cortical cataract, and 23 eyes without any pathological lens changes, the maximal fluorescence intensity was determined after excitation with monochromatic light at 365 nm, 405 nm, 436 nm, and 485 nm. The coefficient of variation was smaller than 5%. All eyes with cataract underwent cataract surgery a few days after the fluorescence measurements. The fluorescence spectrometer, especially constructed for in vivo measurements, consists of a modified slit lamp (Zeiss 75 SL) and an optical multichannel analyser (OMA) for gauging the data. The clinical trial was undertaken to determine whether, considering the influence of age, there is a difference between the fluorescence intensities in eyes with the above named cataracts and noncataractous eyes. The data were analyzed to determine the effect of age upon fluorescence intensity for all excitation wavelengths in both cataractous and noncataractous eyes. Age had an influence on the fluorescence intensities for all four excitation wavelengths. Assuming that the influence of age was not dependent on the state of the lens, it was quantified for all measurements and an "age-corrected" fluorescence intensity was calculated. The statistical analyses of these "age-corrected" fluorescence intensities revealed a significant difference (P < 0.001) for all of the types of cataracts examined and for normal eyes. The cataract types examined and the normal eyes showed differences in their fluorescence feature. To assess the fluorescence intensities obtained after excitation with the wavelengths mentioned above, one must take into consideration the influence of age on the measurements.

Adult↗
PubMed2005

[Pathological cataracts in systemic diseases].

PURPOSE: To show the physiopathological mechanisms which determines the appearance of the pathological cataract and types of cataract and clinical manifestations of the systemic disease and operative complications. METHOD: Retrospective study that includes 22 patients hospitalized in clinic with pathological cataract diagnosis, appeared in following systemic disease: diabetes mellitus, skin disease, endocrine disease, SNC disease. RESULTS: Generally the patients had posterior subcapsular cataract or nuclear and posterior subcapsular cataract with fast evolution to intumescent cataract. Phacoemulsification with IOLCP performed at all patients. Good evolution and not surgery complications. CONCLUSIONS: The difficult of the surgery was connected with the risk of the posterior capsular break ( the majority cases were soft cataract) and also connected with the capsulorhexis making in intumescent cataracts. The post surgery evolution was not different compared with a usually cataract.

Adult↗
PubMed2006

[Compare the proteasome activity in the epithelium of human age-related cataract and normal lens].

PURPOSE: To compare the chymotrypsin-like and trypsin-like activity of proteasome in the epithelium of human age-related cataract and normal lens, in order to study the mechanism of the proteasome in the formation and development of age-related cataract. METHODS: Cataractous lens were obtained during cataract surgery of Zhongshan Ophthalmic Center, and normal age-matched lens were obtained from Guangdong eye bank. The capsules were frozen and thawed repeatedly to ensure the epithelial cells detached from the capsules, then the capsules were removed. All samples were added with LLVY or VGR, then detected the fluorescent intensity at different time. RESULTS: The proteasome activity of normal lens epithelium was significantly high than cataractous lens epithelium (P < 0.01); the chymotrypsin-like activity of the proteasome of cortical and non-cortical cataract had no difference (P > 0.05); MG-132 can significantly inhibit the proteasome activity of cataractous and normal lens. CONCLUSION: Compared to normal age-matched lens, chymotrypsin-like and trypsin-like activity of proteasome in the epithelium of age-related cataract lens were significantly declined, indicating that the decrease of the proteasome activity may play an important role in the formation and development of age-related cataract.

Aged↗
PubMed1989

Prevention and reversal of cataracts in genetically hypertensive rats through sodium restriction.

We previously described the Dahl salt-sensitive rat as a potential model of cataractogenesis in which cataract formation is associated with hypertension. Cataractous lesions were characterized by a marked lenticular and aqueous humor electrolyte imbalance. In the present study the effects of chronic dietary sodium restriction on cataract formation were evaluated in salt-sensitive rats to determine whether or not modification of the hypertensive process might reduce the incidence of cataracts in this genetic model. In addition, the possibility that early cataractous lesions in adult hypertensive salt-sensitive rats might be reversed by acute sodium restriction was evaluated. Chronic dietary sodium restriction modified the development of hypertension and prevented cataract formation in salt-sensitive rats. Furthermore, acute dietary sodium restriction (1 week) completely and consistently reversed early cataractous lesions (pinpoint opacities) in adult hypertensive salt-sensitive rats. Both the prevention and reversal of cataracts were associated with normalization of the lenticular and aqueous humor parameters measured. These data suggest that cataractogenesis is not the consequence of sustained arterial hypertension, but rather that initiation of both hypertension and cataract formation in this genetic model may be the result of extracellular fluid volume state.

Aging↗
PubMed1989

[Cataract epidemiological study in west Sumatra].

A cataract epidemiology survey using a photo-documentation system was performed for people over age 40 who live in West Sumatra Island. The percent prevalence of cataracts, including early senile changes, were 28.7% in the 50 year-old population, 64.7% in the 60, 83.8% the 70 and 95.8% for people over 80. Prominent cataractous opacification was recognized in 8.8% the 50-59 year old population, 21.1% for those in their 60s, 38.7% for those in their 70s and 83.3% in people over 80. The most frequently observed cataract types were cortical and nuclear, followed by mixed types which had almost the same ratio. The incidence of nuclear cataracts was 3.5% and 8.5% in the 40-49 and 50-59 year-old population, respectively. The percent of nuclear cataracts seen in the 60 and 70 year-old population were 22.7% and 32.4%, respectively. Cataract incidence in 50-59 year-old diabetic subjects was significantly higher than that in non-diabetic subjects. Cataract incidence in 50-59 year-old subjects with high myopia was significantly higher than in cares of other types of refractive error. The main type of lens opacification seen in the high myopia cases was nuclear. Cataract prevalence in the 50 year-old age group who had received a high level of education was significantly lower than that of others.

Adult↗
PubMed1986

Free epsilon amino groups and 5-hydroxymethylfurfural contents in clear and cataractous human lenses.

The free epsilon-amino groups and 5-hydroxymethylfurfural (5-HMF) contents were determined in soluble and insoluble proteins of clear human lenses and diabetic and nondiabetic senile cataractous lenses. The free epsilon-amino group content of soluble proteins in diabetic cataracts was decreased by 37% (P less than 0.01), whereas in nondiabetic senile cataracts it did not differ from that of clear lenses. The free epsilon-amino group content of insoluble proteins both in diabetic and nondiabetic cataracts was decreased significantly (P less than 0.001, P less than 0.015, respectively). The 5-HMF content of soluble proteins in diabetic cataracts was increased by 52% (P less than 0.001), whereas in nondiabetic cataracts it did not change from that of clear lenses. The 5-HMF content of insoluble proteins in diabetic as well as in nondiabetic cataracts was increased significantly as compared to that of clear lens (P less than 0.001, P less than 0.001, respectively). The soluble protein of diabetic and nondiabetic cataracts was decreased with an increase in the insoluble protein content. These results suggest that nonenzymatic glycosylation plays a role in the conformational change of lens proteins in both diabetic and nondiabetic cataracts.

Cataract↗
PubMed1985

Dietary prevention of cataracts in the pink-eyed RCS rat.

The American Institute of Nutrition purified ingredient diet (AIN-76) prevented occurrence of mature cataracts associated with hereditary retinal degeneration in pink-eyed, tan-hooded Royal College of Surgeons (RCS) rats. Rats fed a natural ingredient open formula NIH diet or a closed formula commercial diet had a cataract incidence of 27-29% by 3 to 12 months of age. In contrast, only 1 of 50 rats fed the AIN diet developed a mature cataract in one year. When the NIH diet and the commercial diet were pelleted with 25% of ground sunflower kernels, rats fed these diets had a delay in onset and a reduced incidence of mature cataracts to 18% and 5%, respectively. No mature cataracts occurred in rats fed the AIN diet supplemented with 25% sunflower kernels. All diets were fed to the parental generation as well as the progeny (experimental group). The rats were reared at a low level of illumination (1-3 footcandles inside the cage) to minimize effects of light. Prevention of mature cataracts by the AIN purified diet suggests that diets permitting cataracts to occur may have a constituent at a concentration innocuous for normal rats but beyond the homeostatic control of the RCS rat. Posterior subcapsular cataracts of RCS rats are a model for cataracts associated with human hereditary retinal degenerations, such as retinitis pigmentosa and gyrate atrophy. Manipulation of dietary ingredients allowed by the use of the AIN diet may permit identification of nutrients, nutrient interactions of toxic factors involved in cataractogenesis and its prevention.

Animal Feed↗
PubMed1983

Changes in the distribution of lens calcium during development of x-ray cataract.

The present study was designed to examine the possible role of calcium in the opacification of x-ray-induced cataract in rabbit. The results demonstrate that the concentration of calcium in x-rayed lenses, just prior to lens hydration (7.5 weeks postirradiation), was twice that present in contralateral control lenses. At this stage of immature cataract, the lens nucleus remained transparent and maintained a normal level of calcium, but the lens cortex, containing regions of subcapsular opacification, accumulated a level of calcium that was twice that of the control. In the completely opaque mature cataract, (8-9 weeks postx-ray), both the cortex and nucleus had gained significant amounts of calcium. As the concentration of total calcium increased in the immature x-ray cataract, the amount of the cation bound to membranes and insoluble proteins of the cytosol also increased comparably. However, the relative proportion of calcium in the various fractions remained unaltered in the immature cataract; in both control lenses and immature cataracts, 20% of the total calcium remained in the membrane pellet and 70% was located in the soluble protein fraction. Only in the mature stage of cataract was a shift in the distribution of calcium apparent, as the proportion of calcium in the soluble protein fraction increased to 90%. Although only 7% of the total calcium in a mature cataract was bound to membrane, the amount represented a fivefold increase over the control. The results of this study demonstrate that an elevation in lens calcium accompanies the opacification process in x-ray cataract. The work also suggests that changes in calcium levels are not likely to result from inactivation of Ca-ATPase.

Animals↗
PubMed1983

Analysis of low molecular weight fractions in human senile cataractous lens.

Previous studies have suggested that changes occur in low molecular weight proteins during the progression of human senile cataract. In this report we have employed the reverse phase mode of high performance liquid chromatography (HPLC) and characterized the patterns of changes in the fractions of low molecular weight substances. Two different types of cataractous lenses, brown and yellow types, were used. Classification of cataract stages in each type was determined by measuring the Na+/K+ ratio in each lens. The profile of low molecular weight substances loosely bound to the reverse phase column changed significantly during cataract progression. In the brown type cataractous lenses, however, the low molecular weight substances changed after the middle stage of cataract progression, while in the yellow type cataractous lenses, the changes started during the early stages of cataract development. These experiments demonstrated that the reverse phase mode of HPLC is a sensitive and specific method for characterization of the quantitative differences in low molecular weight compounds during the progression of human senile cataract.

Aged↗
PubMed1983

Biometry and clinical characteristics of congenital cataracts and microphthalmia in the Miniature Schnauzer.

Forty-two Miniature Schnauzer pups and adults with congenital cataracts and microphthalmia were evaluated by serial ophthalmic examinations, slit lamp biomicroscopic photography, and A-scan ultrasonography. The cataracts were evident when the eyelids opened at 2 weeks, affecting predominantly the lens nucleus and posterior cortex. Lenticonus was evident in 19% of the cataractous lenses. Progression of the cataracts was variable and related to involvement of the equatorial and posterior cortices. Lens-induced uveitis developed in some adult dogs with advanced hypermature cataracts. The globe and lens were smaller than normal in the cataractous eyes, as ascertained by A-scan ultrasonography. Age-matched comparisons of clear lens carrier Miniature Schnauzers and normal Beagles with the cataractous Miniature Schnauzers indicated affected globes and cataractous lenses were reduced 10% to 20% in their anteroposterior lengths. The microphthalmia appeared related to the congenital microphakic cataract.

Animals↗
PubMed1982

Reduced, oxidized, and protein-bound glutathione concentrations in normal and cataractous lenses in the dog.

Amounts of reduced, oxidized, and protein-bound glutathione (GSH) were measured in normal and cataractous lenses of pups and adult dogs. Lenses from pups included normal lenses from clinically normal pups, clear lenses from Beagle pups bred for glaucoma, and congenital cataractous lenses from Miniature Schnauzer pups. Lenses from adults included normal lenses from normal mixed-breed dogs, congenital cataractous lenses from Miniature Schnauzers, and complete mature cataractous lenses from clinical patients of different breeds. Glutathione in the normal lenses from pups and adult dogs is predominantly reduced GSH; oxidized GSH is about 2.1% to 2.6% of the reduced GSH values. The reduced GSH values are lower in normal pups [7.08 mumoles/g (wet wt) of lens] than in adults [7.83 mumoles/g (wet wt) of lens]; reduced GSH values decrease further in cataract formation. The decrease in oxidized GSH values parallel those of reduced GSH, except in the advanced cataracts of clinical patients in which oxidized GSH [0.045 mumoles/g (wet wt) of lens] was 9% of the GSH values. The GSH bound to soluble and insoluble lens proteins of congenital cataractous Miniature Schnauzer pups was significantly (P less than 0.01 and P less than 0.02, respectively) lower per gram of protein than that in pups with normal lenses. However, the soluble and insoluble protein-bound GSH of congenital cataractous lenses of adult Miniature Schnauzers and lenses in clinical patients with mature cataracts [based on mumole of GSH/g (wet wt) of lens] were not significantly different (P greater than 0.05) from that in adult dogs with normal lenses.

Aging↗
PubMedDate not supplied

Increased lipid peroxidation and altered membrane functions in Emory mouse cataract.

Lipid peroxidation has been shown to be involved in the pathogenesis of some types of cataract. The possibility of such a mechanism was investigated in Emory mouse cataract. Malondialdehyde, a breakdown product of lipid peroxides, increased 4-fold in advanced cataract. Studies on cation transport revealed that in early cataract there was no alteration in permeability and active transport of cations. However, these functions were significantly altered in advanced cataract as evidenced by about 300% increase in cellular influx of 22Na+ (140 mM) and 50% fall in cellular uptake of 86Rb+ (5 mM). At this stage of cataract, the ouabain- inhibitable component of uptake of Rb+ was drastically decreased, whereas the ouabain-resistant component was unchanged. The mannitol-space increased markedly with progression of cataract. Altered transport of cations in cataract was indicative of damaged membranes which may be due to peroxidation of unsaturated fatty acids in the lipid bilayers concomitant with oxidation of sulfhydryl groups of proteins of the plasma membrane. Superoxide dismutase, catalase and glutathione peroxidase, the defensive enzymes against reactive species of oxygen, were decreased 54%, 57% and 62% respectively in cataract, exposing the lens to oxidants such as 02(-), H202, 0H. and 1 delta 02, which can initiate lipid peroxidation and/or oxidation of protein.

Animals↗
PubMed1994

PVEP in patients with different types of congenital cataract.

The preoperative and postoperative PVEP in 79 eyes of 45 patients with three types of congenital namely lamellar cataract, nuclear cataract and total cataract was studied. The results showed that visual acuity of patients who could be cooperatively examined was improved significantly after operation. The examination of PVEP revealed that more abnormal waveforms were found in total cataract group before operation. P1 latencies of low and medium spatial frequencies (140', 70', and 35') became much longer in total cataract group than those in lamellar and nuclear cataract groups. The abnormal changes of P1 latency of high spatial frequency (17.5') showed similar in three groups. It is suggested that time for surgery should be based on visual function in the different types of congenital cataract. The total congenital cataract and unilateral cataract should be extracted as early as possible.

Adolescent↗
PubMed1993

[Malonaldehyde, superoxide dismutase and human cataract].

UV-spectrophotometry and fluorometry were used to study Malonaldehyde (MDA) and Superoxide Dismutase (SOD) in normal, cataractous human lenses and red blood cells of the patients with cataract. MDA content of senile and complicated cataractous lenses was significantly higher than that of normal human lenses, while that of complicated cataract was significantly higher than that of senile cataract. SOD activity of senile and complicated cataractous lenses was significantly lower than that of normal human lenses, while there was no marked difference between senile and complicated cataractous lenses. Significant correlation between cataractous lenses and red blood cells was not found in MDA content and SOD activity. There was a negative correlation between SOD and MDA in normal human lenses, but no correlation between SOD and MDA in cataractous lenses. The study shows that lipid peroxidation may be one of the possible mechanisms of cataractogenesis in human, and emphasizes the role of SOD in prevention of photoperoxidative damages to the tissues.

Adult↗
PubMed1994

Abnormalities in serum lipids and leukocyte superoxide dismutase and associated cataract formation in patients with atopic dermatitis.

BACKGROUND AND DESIGN: Because lipid peroxides are believed to play a role in cataract formation, we examined serum lipid and lipid peroxide levels in patients with atopic dermatitis (AD) complicated by cataract formation in comparison with AD patients without cataracts and patients with other forms of dermatitis, taking into account any treatment with corticosteroids. Since reactive oxygen species play an important role in lipid peroxide formation, the induction of leukocyte superoxide dismutase, which scavenges reactive oxygen species and inhibits lipid peroxidation, was also examined. Most of the patients with AD and cataract were older than 13 years, and had severe, treatment-resistant dermatitis. RESULTS: Serum levels of chylomicrons, very-low-density lipoprotein, and lipid peroxide levels were increased, and superoxide dismutase activity was markedly less inducible in patients with cataracts. These abnormalities demonstrated were irrespective of previous topical corticoid treatment. Although AD patients without cataracts also showed significant abnormalities in all of the parameters measured, these were less marked than in the AD patients with cataracts. In contrast, these findings were not observed in patients with other forms of dermatitis who had been receiving prolonged topical corticosteroid therapy. CONCLUSIONS: High levels of serum lipids and decreased superoxide dismutase inducibility thus appear to be correlated with AD and also independently with attendant cataract formation. From the observation that most of the patients originated from areas of high environmental pollution whose products are known to produce great amounts of reactive oxygen species, excessive lipid peroxide formation, perhaps in part environmentally induced, seems to correlate to severe, adult-type AD with cataract formation.

Adolescent↗
PubMed1993

Concanavalin A-induced posterior subcapsular cataract: a new model of cataractogenesis.

PURPOSE: To evaluate the effect of Concanavalin A (Con A) on cataract formation in New Zealand Albino rabbits. Uveitis is a chronic inflammatory condition of the eye involving the anterior and/or posterior segments. It may be acute or chronic and is associated with the development of posterior subscapular cataract over time. Con A is a nonspecific inflammatory agent and mitogen for T cells and some B cells. Used extensively in immunogenic studies Con A has been shown to induce uveitis after intravitreal injection in New Zealand Albino rabbits. METHODS: In two separate studies, Con A was injected intracamerally or intravitreally into one eye of 12 New Zealand Albino rabbits and an equal volume of balanced salt solution was injected into the opposite eye as a control. In a third study, the effect of topical steroids after intravitreal injection of Con A was evaluated. In all studies, anterior and posterior inflammation and the development of cataract was monitored by slit lamp biomicroscopy and photography. Cataract formation was also studied histopathologically. RESULTS: Initially, all eyes treated with Con A demonstrated moderate anterior chamber inflammation while eyes treated with balanced salt solution showed no inflammation. Three months after treatment, posterior subcapsular cataracts were present in all rabbit eyes treated with intravitreal Con A. In the third study, topical steroid treatment of Con A-induced inflammation significantly reduced anterior chamber inflammation but had no effect on vitreous humor and posterior subcapsular cataract formation. CONCLUSION: This experimental model was the first to demonstrate the development of posterior subcapsular cataracts after Con-A induced inflammation. The cataract was clinically and histologically similar to human posterior subscapular cataracts.

Administration, Topical↗
PubMed1995

Establishment of the hereditary cataract rat strain (SCR) and genetic analysis.

The Shumiya cataract rat (SCR) and normal control rat strains of NC1 and NC2 were established. Mean cataract appearance in adult SCR rats was 66.7%, and embryo death rate was 25%. Genetic analysis of cataract formation in the SCR was studied by breeding experiments with strains such as NC1, BUF, ACI, AD3, and normal SCR rats. No sex-based differences in cataract appearance were observed in any of the progeny. These results confirmed our hypotheses that two autosomal genes, a recessive cataract gene (ctr1), and a normal allele of a dominant cataract gene with a recessive lethal trait (Ctr2(1)) for provisional designations participated in cataract genesis in SCR (ctr1/ctr1, Ctr2(1)/Ctr2) rats. One recessive cataract gene was maintained in normal SCR, NC1 and NC2 (ctr1/ctr1, Ctr2/Ctr2) rats. The same recessive cataract gene was retained in the albumin-deficient brown hooded rat strain AD3 (ctr1/ctr1, Ctr2/Ctr2).

Animals↗