Incidence Of Cataract Extraction Research Articles

Antioxidant vitamin supplementation for preventing and slowing the progression of age-related cataract.

Age-related cataract is a major cause of visual impairment in the elderly. Oxidative stress has been implicated in its formation and progression. Antioxidant vitamin supplementation has been investigated in this context. To assess the effectiveness of antioxidant vitamin supplementation in preventing and slowing the progression of age-related cataract. We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 2), MEDLINE (January 1950 to March 2012), EMBASE (January 1980 to March 2012), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to March 2012), Open Grey (System for Information on Grey Literature in Europe) (www.opengrey.eu/), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 2 March 2012. We also checked the reference lists of included studies and ongoing trials and contacted investigators to identify eligible randomized trials. We included only randomized controlled trials in which supplementation with one or more antioxidant vitamins (beta-carotene, vitamin C and vitamin E) in any form, dosage or combination for at least one year was compared to another antioxidant vitamin or to placebo. Two authors extracted data and assessed trial quality independently. We pooled results for the primary outcomes, i.e., incidence of cataract and incidence of cataract extraction. We did not pool results of the secondary outcomes - progression of cataract and loss of visual acuity, because of differences in definitions of outcomes and data presentation. We pooled results by type of cataract when data were available. We did not perform a sensitivity analysis. Nine trials involving 117,272 individuals of age 35 years or older are included in this review. The trials were conducted in Australia, Finland, India, Italy, the United Kingdom and the United States, with duration of follow-up ranging from 2.1 to 12 years. The doses of antioxidant vitamins were higher than the recommended daily allowance. There was no evidence of effect of antioxidant vitamin supplementation in reducing the risk of cataract, cataract extraction, progression of cataract or in slowing the loss of visual acuity. In the pooled analyses, there was no evidence of effect of beta-carotene supplementation in reducing the risk of cataract (two trials) (relative risk (RR) 0.99, 95% confidence interval (CI) 0.91 to 1.08; n = 57,703) or in reducing the risk of cataract extraction (three trials) (RR 1.00, 95% CI 0.91 to 1.10; n = 86,836) or of vitamin E supplementation in reducing the risk of cataract (three trials) (RR 0.97, 95% CI 0.91 to 1.04; n = 50,059) or of cataract extraction (five trials) (RR 0.98, 95% CI 0.91 to 1.05; n = 83,956). The proportion of participants developing hypercarotenodermia (yellowing of skin) while on beta-carotene ranged from 7.4% to 15.8%. There is no evidence from RCTs that supplementation with antioxidant vitamins (beta-carotene, vitamin C or vitamin E) prevents or slows the progression of age-related cataract. We do not recommend any further studies to examine the role of antioxidant vitamins beta-carotene, vitamin C and vitamin E in preventing or slowing the progression of age-related cataract. Costs and adverse effects should be weighed carefully with unproven benefits before recommending their intake above recommended daily allowances.

Hormone Replacement Therapy in Relation to Risk of Cataract Extraction: A Prospective Study of Women

To investigate the association between hormone replacement therapy (HRT) and the incidence of cataract extraction among postmenopausal women. Population-based, prospective cohort study. A total of 30 861 postmenopausal women participating in the Swedish Mammography Cohort, age 49 to 83 years, who completed a self-administered questionnaire in 1997 about hormone status, HRT, and lifestyle factors. The women were followed from September 1997 through October 2005. The cohort was matched with registers of cataract extraction in the study area. Incident operative extraction of age-related cataract. We identified 4324 incident cases of cataract extractions during 98 months of follow-up. In multivariate adjusted analysis, ever use of HRT was associated with a 14% increased risk of cataract extraction (rate ratio [RR], 1.14; 95% confidence interval [CI], 1.07-1.21) compared with those who never used HRT. Current use of HRT was associated with an 18% increased risk of cataract extraction (RR, 1.18; 95% CI, 1.10-1.26). A significant linear trend was observed where increasing duration of HRT usage resulted in an increased risk of cataract extraction (P for trend = 0.006). Multivariate RR for current HRT usage for >10 years was 1.20 (95% CI, 1.06-1.36; P for trend = 0.001). Among women drinking on average >1 drink of alcohol per day, current HRT users had a 42% increased risk (RR, 1.42; 95% CI, 1.11-1.80) for cataract extraction, compared with women who neither used HRT nor alcohol. The risk of cataract extraction among current users of HRT was similar among current smokers and those who never smoked. Our prospective, population-based study indicates that postmenopausal women using HRT for a long period of time may be at an increased risk for cataract extraction, especially those drinking >1 alcoholic drink daily.

Metabolic Syndrome Components in Relation to Risk of Cataract Extraction: A Prospective Cohort Study of Women

To investigate the association between metabolic syndrome and some of its components with the incidence of cataract extraction. Population-based prospective cohort study. A total of 35,369 women, participating in the Swedish Mammography Cohort, aged 49 to 83 years, who completed a self-administered questionnaire about anthropometric measurements and lifestyle factors in 1997. The women were followed from September of 1997 to October of 2005. The cohort was matched with registers of cataract extraction in the study area. Incident surgical extraction of age-related cataract. We identified 4508 incident cases of cataract extractions during 98 months of follow-up. In multivariate analysis, women with a waist circumference >or=80 cm had an 8% increased risk of cataract extraction (rate ratio [RR], 1.08; 95% confidence interval [CI], 0.99-1.17). Women with diabetes had a 43% increased risk of cataract extraction (RR, 1.43; 95% CI, 1.10-1.86), and hypertension was associated with a 12% increased risk (RR, 1.12; 95% CI, 0.99-1.26). Women with all 3 components of the metabolic syndrome (waist >or=80 cm, diabetes, and hypertension) had a 68% increased risk of cataract extraction (RR, 1.68; 95% CI, 1.40-2.02) compared with women without any of these components. Among women aged less than 65 years at baseline with all 3 components of metabolic syndrome, the risk of cataract extraction was approximately 3-fold more (RR, 2.80; CI, 1.94-4.03). Metabolic syndrome and its components, abdominal adiposity, diabetes, and hypertension, seem to be associated with an increased risk for cataract extraction, especially among women aged less than 65 years.

Intensity of Smoking and Smoking Cessation in Relation to Risk of Cataract Extraction: A Prospective Study of Women

The authors investigated the association of smoking and smoking cessation with the incidence of cataract extraction in a population-based prospective cohort study. A total of 34,595 women aged 49-83 years in the Swedish Mammography Cohort were followed from September 1997 through June 2002. Information on smoking, diet, and other lifestyle factors was collected through a self-administered questionnaire. A total of 2,128 cases of age-related cataract extraction were identified. Relative risks were estimated as rate ratios using Cox proportional hazards models. The authors observed a significant dose-response association between intensity of smoking and risk of cataract extraction (among current smokers, p for trend = 0.02; among past smokers, p for trend = 0.0002). After cessation of smoking, the risk decreased with time. Among women with a moderate lifetime smoking intensity (6-10 cigarettes/day), the relative risk was not significantly different from the risk among never smokers 10 years after smoking cessation. Among women who had smoked more intensively (>10 cigarettes/day), after 20 years of nonsmoking the increased risk became small and no longer statistically significant in comparison with never smokers (for trend over time, p < 0.0001). This prospective study confirmed smoking as a risk factor for cataract, with a dose response for smoking intensity. Smoking cessation predicts reduced risk over time, but a longer period of time is needed with a higher smoking intensity.

A prospective study of the relationship between body mass index and cataract extraction among US women and men.

Obesity may influence several physiologic processes involved in cataract formation such as oxidative stress, glycosylation and osmotic stress. To examine the association between increased body mass index (BMI) and the incidence of cataract extraction. The Nurses' Health Study and the Health Professionals Follow-up Study, both prospective cohort studies of US women and men. A total of 87 682 women and 45 549 men aged 45 y and older who did not have diagnosed cataract or cancer at baseline (1980 for women, 1986 for men). Cataract extractions occurring between baseline and 1996, confirmed by medical records. During 16 y of follow-up in the women, and 10 y in the men, (1 097 997 person-y), 4430 incident cases were documented. Compared to participants with BMI less than 23 kg/m(2), those with BMI greater than or equal to 30 kg/m(2) had 36% higher risk of any type of cataract (pooled multivariate relative risk (RR), 1.36; 95% CI, 1.23-1.49) after adjusting for smoking, age and lutein/zeaxanthin intake. The association was strongest for posterior subcapsular (PSC) cataract (pooled multivariate RR, 1.99; 95% CI, 1.55-2.55). With adjustment for diabetes, the RR of obesity associated with posterior subcapsular cataract was 1.68 (95% CI, 1.30-2.17). Obesity was not significantly associated with nuclear cataract. Obesity increases the risk of developing cataract overall, and of PSC cataract in particular; the etiology of PSC cataract may be mediated at least in part by glucose intolerance and insulin resistance, even in the absence of clinical diabetes.

Smoking cessation and risk of cataract extraction among US women and men.

Although the observational evidence linking cigarette smoking with risk of senile cataract is well-established, it is unclear whether any benefit is obtained from quitting smoking. Therefore, in this study, the authors examined the association between time since quitting smoking and incidence of cataract extraction in women and men enrolled in the Nurses' Health Study and the Health Professionals Follow-up Study, respectively. There were 4,281 incident physician-confirmed cases of cataract and 1,038,493 accumulated person-years of follow-up. Compared with current smokers, former smokers who had quit smoking 25 or more years previously had a 20% lower risk of cataract extraction after adjustment for age, average number of cigarettes smoked per day, and other potential risk factors (relative risk (RR) = 0.80, 95% confidence interval (CI): 0.71, 0.91). However, risk among past smokers did not decrease to the level seen among never smokers (for never smokers, RR = 0.64, 95% CI: 0.52, 0.79). The observed relation was similar when data were examined by cataract subtype (>25 years since quitting vs. current smoking: primarily nuclear cataract, RR = 0.82, 95% CI: 0.68, 0.97; primarily posterior subcapsular cataract, RR = 0.90, 95% CI: 0.71, 1.13). These findings suggest that any healing from damage due to cigarette smoking occurs at a very modest pace, and they emphasize the importance of never starting to smoke or quitting early in life.

A Prospective Study of Vitamin Supplement Intake and Cataract Extraction among U.S. Women

We conducted a prevalence case-control study to investigate the relation between family composition, infection, and development of asthma at age 7-9 years. Potential cases (399) and controls (398) were selected from the Wellington, NZ, arm of the International Study of Asthma and Allergies in Childhood, a population-based prevalence study. Further screening questions restricted cases to children with a diagnosis of asthma and current medication use (N = 233) and restricted controls to children without a history of wheezing and no diagnosis of asthma (N = 241). After controlling for confounders (including infections, atopy, and socioeconomic status), family size was strongly related to asthma. Having no siblings [prevalence odds ratio (POR) = 2.51; 95% confidence interval (CI) = 1.05-6.01] or one sibling (POR = 1.86; 95% CI = 1.14-3.03) was associated with an increased risk of asthma compared with having more than one sibling. Parent-reported rubeola infection (and possibly other similar viral exanthems) was independently associated with a decreased risk of asthma (POR = 0.48; 95% CI = 0.27-0.83), but reported pertussis infection (POR = 1.57; 95% CI = 0.58-4.24) and day care attendance in the first year of life (POR = 1.81; 95% CI = 0.93-3.51) were not strongly associated with increased risks of asthma.

Incidence of cataract extraction in Pima Indians. Diabetes as a risk factor.

The incidence of visually disabling cataract was estimated by the rate of first cataract extraction in a population of Pima Indians in Arizona. The annual age-specific rates of cataract surgery (first and second eyes) were 3.7 to 5.9 times as high as the estimated US rates. Diabetes was a strong risk factor for first cataract surgery in all age and sex groups except in men aged 75 to 84 years. Overall, with age and sex controlled, the rate of first cataract surgery was 2.2 times as high (95% confidence interval, 1.3 to 3.9) in diabetic as in nondiabetic subjects. Cataract surgery was related to the duration and type of treatment of diabetes. Insulin-treated diabetics had about five times the rate of those with normal glucose tolerance. The rate of cataract surgery was lowest in subjects with normal glucose tolerance, somewhat higher in those with impaired glucose tolerance, and even higher with increasing duration of diabetes.