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PubMed2003

Associations of cataract with antioxidant enzymes and other risk factors: the French Age-Related Eye Diseases (POLA) Prospective Study.

PURPOSE: To determine the association of potential risk factors, including antioxidant enzymes, with the incidence of cataract. DESIGN: Cohort study. PARTICIPANTS: At baseline, the Age-Related Eye Diseases (Pathologies Oculaires Liées à l'Age, POLA) Study included 2584 residents of Sète (southern France) aged 60 years or older. From September 1998 to May 2000, a 3-year follow-up examination was performed on 1947 of the 2436 surviving participants (79.9%). METHODS: Cataract classification was based on a standardized lens examination at the slit lamp, according to Lens Opacities Classification System III. Biologic measurements were performed at baseline from fasting blood samples. MAIN OUTCOME MEASURES: At baseline and follow-up, the presence of cataract was defined as: NC or nuclear opalescence (NO) > or = 4 for nuclear cataract, C > or = 4 for cortical cataract, and P > or = 2 for posterior cataract (PSC) opacities, using opacity grades corrected for interobserver variability. Incidence rates were assessed separately for right and left eyes and for each type of cataract. RESULTS: In the multivariate model, the incidence of cortical cataract was increased in subjects with high red blood cell superoxide dismutase activity (odds ratio [OR] 4.2 [1.5-12.1], P = 0.007). The incidence of PSC cataract was increased in subjects with a high level of plasma glutathione peroxidase (OR 1.8 [1.0-3.3], P = 0.05). In addition to age, gender, and opacities at baseline, significant risk factors for incident cataract were: long-duration diabetes (OR 5.8, P = 0.001 for cortical cataract) and lifetime heavy smoking (OR 2.9, P = 0.006 for PSC cataract). CONCLUSIONS: Consistent with the baseline analysis, the results of this prospective study suggest that antioxidant enzymes might be implicated in the etiology of cataract.

Aged↗
PubMed1990

Distribution of lens opacities in the Italian-American Case-Control Study of Age-Related Cataract. The Italian-American Study Group.

The Lens Opacities Classification System I (LOCS I) was used to classify lens opacities in the clinic-based Italian-American Case-Control Study of Age-Related Cataract. Data on the distribution of cataract types among the 1008 patients (age range, 45-79 years) are presented. A single type of cataract was found in 65% of all cases in whom both lenses could be graded. Among all patients and among patients with only one type of cataract, cortical opacities occurred most frequently and posterior subcapsular opacities least frequently. In patients with bilateral cataracts there was a high degree of concordance of cataract type and severity. The high degree of concordance of cataract type between eyes and the decreasing prevalence of unilateral cataract with increasing age suggest that patients with unilateral cataract are at high risk of developing the same opacity in the fellow eye. Cortical cataracts were found more frequently in women, and in patients with unilateral cataract, the left eye was more frequently affected. Clinic-based data on the distribution of cataract may be of assistance in planning future clinical studies of cataract.

Aged↗
PubMed1998

Medications and cataract. The Blue Mountains Eye Study.

PURPOSE: Corticosteroids are known to cause cataracts, but the effects of other medications on the lens are unclear. The aim of this study was to investigate the relationships between cataracts and a range of medications, including allopurinol, aspirin, chloroquine, diuretics, phenothiazines, and simvastatin. DESIGN: Population-based cross-sectional study. PARTICIPANTS: 3654 individuals 49 to 97 years of age (response rate, 82%) from an urban community near Sydney, Australia, were included. TESTING: Lens photography. PRIMARY OUTCOME MEASURE: Lens photographs were graded for the presence and severity of cortical, nuclear, and posterior subcapsular cataract. RESULTS: After adjusting for numerous potential confounders in ordinal regression models, use of phenothiazines was associated with nuclear cataract (adjusted odds ratio [OR], 2.18; 95% confidence interval [CI], 1.01-4.74); long-term aspirin users (> or = 10 years) had higher prevalence of posterior subcapsular cataract than did nonusers and short-term users (test for trend, P = 0.02); and the antimalarial drug mepacrine was associated with posterior subcapsular cataract (adjusted OR, 3.56; 95% CI, 1.56-8.13). There was a suggestion that use of chloroquine-like drugs for more than 1 year (test for trend, P = 0.12) might also be associated with posterior subcapsular cataract. Antihypertensive medications, cholesterol-lowering drugs, and allopurinol were not associated with any type of cataract. Potassium-sparing diuretics were the only diuretic to show any evidence of an association with cataract (test for trend for posterior subcapsular cataract, P = 0.14). Amiodarone was associated with cortical cataract (age- and gender-adjusted OR, 3.84; 95% CI, 1.01-14.81), but there were too few users to do analyses adjusted for multiple confounders. CONCLUSIONS: Most drugs commonly used in the community do not appear to be associated with cataract. The findings of this study do not support the hypothesis that aspirin protects against cataract.

Age Distribution↗
PubMed1999

The relationship between cataract, cell swelling and volume regulation.

The cause of cataracts is not known. Data from epidemiological and case-control studies have suggested various risk factors, among them; sunlight, diabetes, diarrhoea, oxidative stress, smoking and alcohol. Many reports in the literature suggest that the hydrated state of the lens is linked to cataract and recently direct evidence has emerged linking lens swelling to cataract. This review attempts to collate the various strands of evidence relating the hydrated state of the lens in cataract and to construct a common pathway for cataractogenesis. This common pathway involves lens swelling, membrane permeabilization, vacuole and cleft formation, disturbance to the intracellular environment, protein aggregation/modification and light scatter. This hypothesis gives rise to some testable predictions amongst which is that under certain conditions the lens axial diameter will increase raising the possibility that pre-cataractous changes could be detected (e.g., by ultrasound) and, with appropriate action, the cataract could be prevented or delayed. There are encouraging signs from animal studies that certain types of lens opacification can be delayed or prevented, lending credibility to the objective of cataract prevention in humans. Even a delay in the onset of cataract would have a huge global impact. The incidence of cataract correlates with poverty, poor diet and poor hygiene and the vast majority of cataract is found in developing countries. Economic factors and a lack of cataract surgeons in these countries mean that surgery is not the long-term answer. Prevention is the only realistic global approach. This review concludes that detection of pre-cataractous changes and cataract prevention are achievable objectives and funds should be directed towards their realization.

Animals↗
PubMed2003

Birth prevalence of visually significant infantile cataract in a defined U.S. population.

PURPOSE: To determine the birth prevalence of visually significant infantile cataract, using population-based comprehensive medical record retrieval, in a defined US population. DESIGN: Retrospective, population-based, medical record retrieval. METHODS: We reviewed records of all pediatric patients (0-17 years) coded as cataract during a 20-year period (1978 to 1997) using the resources of the Rochester Epidemiology Project. "Infantile cataract" was defined as a cataract diagnosed within the first year of life. "Possible infantile cataract" was defined as a cataract, diagnosed after the first year in a child born in Olmsted County, where there was no evidence of an acquired traumatic, acquired systemic, or acquired ocular etiology. Visually insignificant cataracts were excluded. RESULTS: Ten incident cases of visually significant infantile cataract were identified during the 20-year study period, yielding a birth prevalence of 3.0 per 10,000 live births (95% CI: 1.5-5.6 per 10,000). Five additional cases of visually significant "possible infantile cataract" were identified, diagnosed between the ages of 2 and 8 years. Inclusion of these "possible infantile cataracts" would result in an estimate of overall birth prevalence for visually significant infantile cataract of 4.5 per 10,000 live births (95% CI: 2.5-7.5 per 10,000). CONCLUSIONS: Using population-based medical record retrieval methods, we estimate the birth prevalence of visually significant infantile cataract to be 3.0 to 4.5 per 10,000. Infantile cataracts are an important cause of visual impairment in children and these data are useful in planning clinical trials and allocating health care resources.

Cataract↗
PubMed2005

Accumulation of the hydroxyl free radical markers meta-, ortho-tyrosine and DOPA in cataractous lenses is accompanied by a lower protein and phenylalanine content of the water-soluble phase.

Post-translational modifications of lens proteins play a crucial role in the formation of cataract during ageing. The aim of our study was to analyze protein composition of the cataractous lenses by electrophoretic and high-performance liquid chromatographic (HPLC) methods. Samples were obtained after extracapsular cataract surgery performed by phacoemulsification technique from cataract patients with type 2 diabetes mellitus (DM CAT, n = 22) and cataract patients without diabetes (non-DM CAT, n = 20), while non-diabetic non-cataractous lenses obtained from cadaver eyes served as controls (CONTR, n = 17). Lens fragments were derived from the surgical medium by centrifugation. Samples were homogenized in a buffered medium containing protease inhibitor. Soluble and insoluble protein fractions were separated by centrifugation. The electrophoretic studies were performed according to Laemmli on equal amounts of proteins and were followed by silver intensification. Oxidized amino acid and Phe content of the samples were also analyzed by HPLC following acid hydrolysis of proteins. Our results showed that soluble proteins represented a significantly lower portion of the total protein content in cataractous lenses in comparison with the control group (CONTR, 71.25%; non-DM CAT, 32.00%; DM CAT, 33.15%; p < 0.05 vs CONTR for both). Among the proteins, the crystallin-like proteins with low-molecular weight can be found both in the soluble and insoluble fractions, and high-molecular weight aggregates were found mainly in the total homogenates. In our HPLC analysis, oxidatively modified derivatives of phenylalanine were detected in cataractous samples. We found higher levels of m-Tyr, o-Tyr and DOPA in the total homogenates of cataractous samples compared to the supernatants. In all three groups, the median Phe/protein ratio of the total homogenates was also higher than that of the supernatants (total homogenates vs supernatants, in the CONTR group 1102 vs 633 micromol/g, in the DM CAT group 1187 vs 382 micromol/g and in the non-DM CAT group 967 vs 252 micromol/g; p < 0.05 for all). In our study we found that oxidized amino acids accumulate in cataractous lenses, regardless of the origin of the cataract. The accumulation of the oxidized amino acids probably results from oxidation of Phe residues of the non-water soluble lens proteins. We found the presence of high-molecular weight protein aggregates in cataractous total homogenates, and a decrease of protein concentration in the water-soluble phase of cataractous lenses. The oxidation of lens proteins and the oxidative modification of Phe residues in key positions may lead to an altered interaction between protein and water molecules and thus contribute to lens opacification.

Aged↗
PubMed2005

A case-control study on risk factors for nuclear, cortical and posterior subcapsular cataract: The Casteldaccia Eye Study.

PURPOSE: To investigate risk factors for nuclear, cortical and posterior subcapsular age-related cataract. METHODS: A case-control study was carried out on subjects aged 40 years and older, living in Casteldaccia, Sicily. Twenty-seven potential risk factors were investigated. Nuclear, cortical and posterior subcapsular opacities of the lens were classified according to the Lens Opacities Classification System II. Subjects with advanced lens opacities represented the cases, while an identical number of subjects without or with early cataract, matched for sex and age, were recruited as controls from within the same population. RESULTS: Univariate analysis showed that myopia and iris atrophy were significantly associated with nuclear cataract. Iris atrophy, use of corticosteroids, pseudoexfoliation syndrome and familial occurrence of cataract were positively correlated with cortical cataract. Myopia, iris atrophy, use of corticosteroids and familial occurrence of cataract presented an association with posterior subcapsular cataract. After multivariate analysis, the variables that remained significantly associated were myopia and iris atrophy for nuclear cataract; iris atrophy, pseudoexfoliation syndrome and familial occurrence of cataract for cortical cataract; and myopia, iris atrophy and familial occurrence of cataract for posterior subcapsular cataract. CONCLUSION: In addition to well known risk factors such as myopia or use of corticosteroids, the Casteldaccia case-control study shows that iris atrophy represents a previously unrecognized risk factor for each of the three types of cataract.

Adult↗
PubMed2002

Aetiology of congenital and paediatric cataract in an Australian population.

BACKGROUND/AIM: Paediatric cataract is a major cause of childhood blindness. Several genes associated with congenital and paediatric cataracts have been identified. The aim was to determine the incidence of cataract in a population, the proportion of hereditary cataracts, the mode of inheritance, and the clinical presentation. METHODS: The Royal Children's Hospital and the Royal Victorian Eye and Ear Hospital have a referral base for almost all paediatric patients with cataracts in south eastern Australia. The database contains cases seen over the past 25 years. The medical histories of these patients were reviewed. RESULTS: 421 patients with paediatric cataract were identified, which gives an estimated incidence of 2.2 per 10,000 births. Of the 342 affected individuals with a negative family history, 50% were diagnosed during the first year of life, and 56/342 (16%) were associated with a recognised systemic disease or syndrome. Unilateral cataract was identified in 178/342 (52%) of sporadic cases. 79 children (from 54 nuclear families) had a positive family history. Of these 54 families, 45 were recruited for clinical examination and DNA collection. Ten nuclear families were subsequently found to be related, resulting in four larger pedigrees. Thus, 39 families have been studied. The mode of inheritance was autosomal dominant in 30 families, X linked in four, autosomal recessive in two, and uncertain in three. In total, 178 affected family members were examined; of these 8% presented with unilateral cataracts and 43% were diagnosed within the first year of life. CONCLUSIONS: In the paediatric cataract population examined, approximately half of the patients were diagnosed in the first year of life. More than 18% had a positive family history of cataracts. Of patients with hereditary cataracts 8% presented with unilateral involvement. Identification of the genes that cause paediatric and congenital cataract should help clarify the aetiology of some sporadic and unilateral cataracts.

Australia↗
PubMed2003

Refractive errors, axial ocular dimensions, and age-related cataracts: the Tanjong Pagar survey.

PURPOSE: To describe the relationship of refractive errors and axial ocular dimensions and age-related cataract. METHODS: Population-based, cross-sectional survey of ocular diseases among Chinese men and women aged 40 to 81 years (n = 1232) living in the Tanjong Pagar district in Singapore. As part of the examination, refraction and corneal curvature were determined with an autorefractor, with refraction further refined subjectively. Ocular dimensions, including axial length, anterior chamber depth, lens thickness, and vitreous chamber depth, were measured with an A-mode ultrasound device. Lens opacity was graded clinically according to the Lens Opacity Classification System (LOCS) III system. Refraction, biometry, and cataract data on right (n = 989) and left (n = 995) eyes were analyzed separately. RESULTS: In analyses controlling for age, gender, education, diabetes, and cigarette smoking, nuclear cataract was associated with myopia (-1.35 D vs. -0.11 D, P < 0.001, comparing right eyes with and without nuclear cataract), but not with any specific biometric component. Cortical cataract was associated with thinner lenses (4.67 mm vs. 4.79 mm, P = 0.001, comparing right eyes with and without cortical cataract), but not with refraction and other biometric components. Posterior subcapsular cataract was associated with myopia (-1.80 D vs. -0.39 D, P < 0.001, comparing right eyes with and without posterior subcapsular cataract), deeper anterior chamber (3.00 mm vs. 2.89 mm, P = 0.02), thinner lens (4.62 mm vs. 4.77 mm, P = 0.001), and longer vitreous chamber (15.78 mm vs. 15.57 mm, P = 0.09), but not with overall axial length and corneal curvature. Adjustment for vitreous chamber depth attenuated the association between posterior subcapsular cataract and myopia by 65.5%, but did not substantially change the association between nuclear cataract and myopia. CONCLUSIONS: These population-based data support the associations between nuclear and posterior subcapsular cataracts and myopia reported in previous studies. Posterior subcapsular cataract is also associated with deeper anterior chamber, thinner lens, and longer vitreous chamber, with vitreous chamber depth explaining most of the association between posterior subcapsular cataract and myopia.

Adult↗
PubMed1996

Inhibition of naphthalene cataract in rats by aldose reductase inhibitors.

Naphthalene-induced cataract in rat lenses can be completely prevented by AL01576, an aldose reductase inhibitor (ARI). In an attempt to understand the mechanism of this inhibition, several ARIs were examined to compare their efficacies in preventing naphthalene cataract, using both in vitro and in vivo models. Two classes of ARIs were tested: One group including AL01576, AL04114 (a AL01576 analog) and Sorbinil contained the spirohydantoin group, while Tolrestat contained a carboxylic acid group. Furthermore, to clarify if aldose reductase played a role in naphthalene-induced cataractogenesis in addition to its role in sugar cataract formation, a new dual cataract model was established for ARI evaluations. This was achieved by feeding rats simultaneously with high galactose and naphthalene or incubating rat lenses in culture media containing high galactose and naphthalene dihydrodiol. Under these conditions, both cortical cataract and perinuclear cataract developed in the same lens. It was found that at the same dosage of 10 mg/kg/day, both AL01576 and AL04114 completely prevented all morphological and biochemical changes in the lenses of naphthalene-fed rats. Sorbinil was less efficacious, while Tolrestat was inactive. AL01576 showed a dose-response effect in preventing naphthalene cataract and at 10 mg/kg/day, it was also effective as an intervention agent after cataractogenesis had begun. With the dual cataract model, Tolrestat prevented the high galactose-induced cortical cataract but showed no protection against the naphthalene-induced perinuclear cataract. AL01576, on the other hand, prevented both cataract formations. Results for dulcitol and glutathione levels were in good agreement with the morphological findings. AL04114, and ARI as potent as AL01576 but without its property for cytochrome P-450 inhibition, displayed similar efficacy in preventing naphthalene cataract. Based on these results, it was concluded that the prevention of the naphthalene cataract probably results from inhibition of the conversion of naphthalene dihydrodiol to 1,2-dihydroxynaphthalene and that the effect of the ARIs cannot be explained by their inhibition of the dihydrodiol dehydrogenase activity of aldose reductase.

Aldehyde Reductase↗
PubMed2003

Galactokinase gene mutations and age-related cataract. Lack of association in an Italian population.

PURPOSE: To investigate possible associations between sequence changes in the galactokinase gene (GALK1) and age-related cataract in a European population. METHODS: Persons without lens opacities and persons with clinically significant age-related cataract were selected from those participating in the Collaborative Italian-American Clinical Trial of Nutritional Supplements and Age-Related Cataract or from those attending the Section of Ophthalmology of the University of Parma for cataract surgery. Type and severity of the opacities were assessed by slit-lamp and retro-illumination lens photographs. Mutations in GALK1 were identified by PCR amplification of individual exons and flanking sequences and sequencing using fluorescent terminator technology in an ABI 377 Prism or 3100 automated DNA sequencer. RESULTS: DNA samples were obtained from 115 individuals with clear lenses and from 185 individuals with cataract (106 with any nuclear, 88 with any cortical, and 25 with any posterior sub capsular cataract). 157 of the 185 patients with cataract (85%) were age-matched with a control within an age range of plus or minus 1 year. SNPs causing amino acid changes in the galactokinase protein were identified in exon 4; I184M, 1/115 control versus 0/185 cataractous individuals, p=0.38, exon 6; G274D, 0/115 control versus 1/185 cataractous individuals, p>0.99, and exon 7; V338A, 0/115 control versus 1/185 cataractous individuals, p>0.99. Thus, there were no significant differences in the distribution of sequence alterations resulting in amino acid changes between control and cataractous individuals. Eighty samples showed a C to T transition 43 bases into intron 7 (46 cataracts and 34 controls). Testing the distribution of the intron 7 findings showed Hardy-Weinberg equilibrium for both cases (p=0.73) and controls (p=0.51). There was no difference in C/T distribution between cases and controls (p=0.27). CONCLUSIONS: In this northern Italian population age-related cataract does not appear to be associated with GALK1 alleles. Since this is due to a lack of sequence changes in both affected and control individuals, this study cannot rule out the possibility of an association in other populations.

Aged↗
PubMedDate not supplied

Clinical features of patients featuring cataracts in a myopia-endemic area of Taiwan.

BACKGROUND: To determine the etiology and morphological features of cataracts in a myopia-endemic area of Taiwan. METHODS: This retrospective case-controlled study comprised 332 patients (440 eyes) who underwent cataract-extraction surgery, 163 patients (220 eyes) constituting the presenile cataract study group, and 169 patients (220 eyes) constituting the senile cataract control group. Each group was divided into idiopathic, diabetic, and highly myopic subgroups. Age, gender, ocular and systemic comorbidities, and the types of cataract featured were recorded and analyzed. For the statistical analysis, chi 2 test was used. RESULTS: The mean ages of study subjects were 45.5 +/- 7.6 years for the presenile and 68.7 +/- 8.0 years for the senile cataract groups. We also observed a greater number of cataracts in highly myopic eyes of the presenile group (17.27%) compared to the senile group (0.90%) (p < 0.0001). The distribution of cataract types for the 3 presenile cataract subgroups revealed that nuclear sclerosis contributed most to presenile cataracts in highly myopic patients (p = 0.001), and correspondingly, the posterior subcapsular opacity contributed most in the idiopathic and diabetic cataract subgroups (p = 0.001). CONCLUSIONS: We observed a greater number of cataracts from highly myopic eyes in the presenile group than in the senile group in southern Taiwan, a myopia-endemic area. Nuclear sclerosis contributed most to the presenile cataracts in the highly myopic subgroup.

Adult↗
PubMed1990

[Cataract--clinic and pathology].

Clinicopathological studies were performed on 156 lenses of human senile cataract obtained by cataract operations between 1970 and 1988. It became clear that the aging influences the functional destruction of the equatorial region, the pathological changes of the bow area, and changes of the extralens environment. After operation for the atrophic type of the posterior subcapsular cataract, aftercataract easily develops on the intraocular lens and this requires treatment. Long-term observations were carried out in 180 Wistar male rats under the same laboratory condition and histological studies were performed. The similarities between the senile Wistar rat cataract and the human senile cataract indicate that the Wistar rat cataract is useful as a model for studying the human senile cataract. These rats were initially classified into six groups (control, vitamin E diet, EPC eye drops, catalin eye drops and reduced catalin eye drops). To study the effects of the agents (vitamin E, ARI, EPC, catalin, reduced catalin) on the cataract in senile Wistar rats the mean cell density of lens epithelia were measured at 2 or 3-month intervals. There were no statistically significant differences in treated groups and the control group. The results suggest that these agents affect another factor of lens apart from the proliferative activity of lens epithelial cell. Effects of anti-cataract agents were investigated using cultured lens epithelial cells. When cultured rat lens epithelial cells were incubated in medium containing selenite, super-oxide dismutase (SOD) activity and GSH in the cells markedly decreased, and GSSG was markedly increased. When cultured rabbit lens epithelial cells were incubated in medium contained selenite and glutathione, SOD activity was maintained normal level. When cultured lens epithelial cells were incubated in medium contained selenite and pirenoxin, SOD activity also maintained a normal level. These results suggest that both glutathione and pirenoxin are effective as anti-cataract agents. Cataracts in spontaneously hypertensive rats (SHR) was investigated on male of Wistar-Kyoto rats (WKY), stroke resistant SHR (SHRSR) and stroke-prone SHR (SHRSP) rats aged 3 to 9 months. Cataracts in these rats were classified as follows: Type 0: no opaciiy, Type 1: nuclear opacity, Type 2: posterior subcapsular opacity, Type 3: nuclear opacity associated posterior subcapsular opacity and Type 4: complete opacity in both lenses. Incidence of cataract in WKY was 2.6%, SHRSR, 76.8% ant SHRSP, 88.2%. Incidence of nuclear opacity was remarkably higher in SHRSP (48.5%). In SHR aged from 3 to 5 months, nuclear opacity was ahead of the appearance of posterior subcapsular opacity which was increased during aging.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1987

The role of autoimmune phenomena in the pathogenesis of cataract.

Investigations were carried out to clarify the role of autoimmune phenomena in the pathogenesis of cataract in the adult human lens. Studies were carried out to determine the presence of serum antibodies to lens protein in patients with senile cataract, in patients with diabetes mellitus with and without cataract, and in healthy adult controls using the interfacial test and the gel-diffusion technique. Non-specific antibodies were removed by adsorption of sera with homogenized rat liver. A high proportion of healthy adults was found to have anti-lens protein antibodies (44.4% by the gel-diffusion method). In contrast, patients with cataract and diabetic patients with no cataract demonstrated double this incidence (82% and 80%), while all diabetic patients with cataract showed the presence of antibodies (P = 0.0002). The possible causes for the development of lens antibodies in normal healthy humans are discussed. Also, the causes for the higher incidence of lens antibodies in patients with cataract and in diabetic subjects with no clinical evidence of cataract are considered in relation to cataract formation. Homogenates of cataractous lenses when investigated revealed the presence of both IgG and IgM immunoglobulins, the former probably to a greater extent. Fluorescent microscopy on cryosections of senile and diabetic cataractous lenses revealed the presence of immunoglobulins within the lens. The antigen in the immune complexes isolated from homogenized cataractous lenses was characterized by the SDS-polyacrylamide gel electrophoresis method. A single band was consistently obtained and the molecular weight of the protein was estimated to be between 35,000 and 40,000. The strong possibility of auto-antibodies to lens protein being of aetiological significance in the pathogenesis of cataract is discussed.

Adult↗
PubMed2004

Blood and aqueous humour antioxidants in cataractous poodles.

BACKGROUND: Cataract is an important cause of blindness in dogs and frequently develops in young animals of certain breeds, such as the English cocker spaniel and the poodle. Protein oxidation is one of the mechanisms involved in lens opacification and may be causally related to depleted or diminished endogenous antioxidant defences. We evaluated the levels of enzymatic and nonenzymatic antioxidants in blood and aqueous humour of cataractous poodles in comparison to noncataractous poodles. METHODS: We studied 35 cataractous poodles aged 2 to 11 years, 14 noncataractous poodles and 15 noncataractous mixed-breed dogs. The activity of erythrocyte antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase and glucose-6-phosphate dehydrogenase [G6PD]) was evaluated in 18 cataractous poodles and 14 noncataractous poodles. We evaluated ascorbic acid levels in plasma of all animals and in aqueous humour of cataractous poodles and mixed-breed dogs. The dogs were deprived of food for 12 hours before sampling. Blood samples were obtained from the jugular vein before and during anesthesia. Aqueous humour samples were obtained just before the anterior chamber was opened. RESULTS: The activity of superoxide dismutase, G6PD and catalase was significantly higher in noncataractous poodles than in cataractous poodles (p < or = 0.05). The activity of glutathione peroxidase was lower in noncataractous poodles than in cataractous poodles, but not significantly so. There was no difference in mean plasma ascorbic acid concentration between cataractous poodles (21.3 microM [standard deviation (SD) 7.4 microM]), noncataractous poodles (21.6 microM [SD 7.4 microM]) and non-cataractous mixed-breed dogs (25.8 microM [SD 7.5 microM]). Similarly, there was no difference in mean aqueous humour ascorbic acid concentration between cataractous poodles (191.7 microM [SD 62.0 microM] and noncataractous mixed-breed dogs (215.7 microM [SD 91.8 microM]). INTERPRETATION: The results indicate that, at least in the population studied here, no correlation exists between the onset of cataract and ascorbic acid concentration in blood and aqueous humour. The decreased activity of antioxidant enzymes may explain in part the onset of cataract in poodles.

Animals↗
PubMed1994

Cataract surgery in patients with sarcoidosis-associated uveitis.

PURPOSE: The authors analyzed the incidence of cataract development and the visual outcome of cataract surgery performed on patients with sarcoidosis-associated uveitis who were treated at the Immunology Service at the Massachusetts Eye and Ear Infirmary during a 17-year period. METHODS: The records of 102 patients with sarcoidosis-associated uveitis who were treated with topical and regional corticosteroids, systemic nonsteroidal anti-inflammatory drugs, systemic steroids, or with systemic immunosuppressive chemotherapy were reviewed. Cataract surgery was performed on those eyes in which cataract developed, resulting in decreased visual acuity of 20/100 or less. The incidence of cataract development and visual results of cataract extraction and intraocular lens implantation were analyzed. RESULTS: In this cohort of 102 patients, visually significant cataracts that warranted surgery developed in 10 (16 eyes). In addition, four patients (5 eyes) had a visually significant cataract at the time of first evaluation. A total of 14 patients (21 eyes) underwent cataract surgery. Posterior chamber lens implantation accompanied cataract surgery in 19 (90.5%) of 21 eyes. The average final visual acuity of the 21 eyes after cataract surgery was 20/51, and 61% of the eyes achieved a stable visual acuity of 20/40 or better. The major causes of the decreased visual acuity in patients who had less than 20/40 visual acuity were sequelae of chronic posterior uveitis, cystoid macular edema, epiretinal membrane, and glaucomatous optic nerve damage. CONCLUSION: Posterior chamber lens implantation and cataract surgery in patients with sarcoidosis-associated uveitis can be well tolerated when absolute control of the inflammation is achieved. Pre-existing retinal pathology and glaucoma as a result of uncontrolled inflammation resulting in permanent ocular structural damage were found to be the most important factors for determining the postoperative final visual acuity.

Adult↗
PubMed2000

Colour contrast sensitivity in cataract and pseudophakia.

PURPOSE: To study the influence of cataract on peripheral and central colour contrast sensitivity. METHODS: Peripheral and central colour contrast sensitivity was measured with a computer graphics system along the protan, deutan and tritan axes. Included were 30 patients with cataract divided into three sub-groups: cortical cataract, nuclear sclerosis and posterior subcapsular cataract. Colour contrast was measured before and after cataract operation. RESULTS: There were significant differences in peripheral colour contrast thresholds comparing the preoperative and postoperative results. This difference existed even in patients (n=19) with a pre-operative visual acuity > or = 0.5 (mean 0.6). The tritan axis was the one most affected by cataract. There was no significant difference between cataract sub-groups. Also, the central colour contrast sensitivity was affected by cataract. Again, the tritan axis was the most affected one. There was no significant difference between the cataract sub-groups. We also found large and significant differences in central colour contrast thresholds between normal subjects and postoperative values from the cataract group in all colour axes. The colour contrast sensitivity was poorer in pseudophakes than in normals. There was a difference between the three groups of different IOL material used (PMMA, acrylic and silicone). The difference was significant in the protan axis, the acrylic group having the best colour contrast sensitivity. CONCLUSION: Peripheral colour contrast sensitivity was affected by cataract, even when only moderately developed. This finding is of importance and should be considered when the method is used to study other eye diseases e.g. glaucoma. Central colour contrast sensitivity was also affected by cataract. The pseudophakes were found to have poorer colour contrast sensitivity than normals. The material in the IOL seemed to be of importance for colour contrast.

Acrylates↗
PubMed1998

Low-dose aspirin and risk of cataract and subtypes in a randomized trial of U.S. physicians.

PURPOSE: To examine whether low-dose aspirin (325 mg on alternate days) reduces the risk of age-related cataract and subtypes. This report extends previous findings, including both subtypes and additional newly identified incident cases since the earlier report. METHODS: All 20,979 participants in the Physicians' Health Study, a randomized trial of aspirin and beta-carotene among U.S. male physicians age 40-84 in 1982, who did not report cataract at baseline were included. Average follow-up was five years. The main outcome measure was incident, age-related cataract responsible for a reduction in best-corrected visual acuity to 20/30 or worse, based on self-report confirmed by medical record review. RESULTS: 501 age-related cataracts were diagnosed during follow-up, including 416 with nuclear sclerosis and 212 with a posterior subcapsular component; 318 cataracts progressed to surgical extraction. Overall, there were 245 cataracts in the aspirin group and 256 in the placebo group (relative risk [RR], 0.94; 95% confidence interval [CI], 0.79 to 1.13; P = 0.52). Cataract extractions were 19% less frequent in the aspirin than in the placebo group (RR, 0.81; 95% CI, 0.65 to 1.01; P = 0.06). In subgroup analyses of subtypes, aspirin takers had a lower risk of posterior subcapsular cataract (RR, 0.74; 95% CI, 0.57 to 0.98; P = 0.03) but not nuclear sclerosis (RR, 0.96; 95% CI, 0.79 to 1.16; P = 0.65) cataract. CONCLUSIONS: Overall, these randomized trial data tend to exclude a large benefit of five years of low-dose aspirin therapy on cataract development and extraction. The data are compatible with a modest benefit on cataract extraction for this duration of aspirin therapy. Subgroup analyses raise the possibility of a modest, but potentially important, protective effect of aspirin on posterior subcapsular cataract, a particularly disabling subtype.

Adult↗