Cataract In Women Research Articles

Association between systemic immune-inflammation index and cataract among outpatient US adults.

While several studies have noted a higher SII correlates with multiple diseases, research on the association between SII and cataract remains limited. Our cross-sectional study seeks to examine the association between SII and cataract among outpatient US adults. This compensatory cross-sectional study utilized NHANES data from 1999 to 2008 cycles, conducting sample-weighted multivariate logistic regression and stratified analysis of subgroups. Among 11,205 adults included in this study (5,571 [46.2%] male; 5,634 [53.8%] female), 2,131 (15.2%) had cataract and 9,074 (84.8%) did not have cataract. A fully adjusted model showed that SII higher than 500 × 109/L was positively correlated with an increased risk of cataracts among women (OR, 1.27; 95% CI, 1.02-1.59) (p = 0.036). However, no difference was found in the men subgroup, and there was no significant interaction between SII and sex. Our results indicated that a SII higher than 500 × 109/L was positively correlated with an increased risk of cataracts in women. This study is the first to specifically investigate the impact of a high SII on cataract risk in outpatient adults in the United States. By effectively addressing inflammation, it is possible to mitigate cataract progression and significantly enhance patient outcomes.

Epidemiological Studies of the Eye Pathology over a Long-Term Follow-Up Period in the Population Affected by Chronic Radiation Exposure in the Southern Urals

Objective of the study: to analyze cataract incidence rates over the period from 1955 through 2019 in the cohort of the population exposed in the Southern Urals and to analyze radiation risk of cataract incidence.Methods. For the first time cataract incidence was assessed over a long- term period from 1955 through 2019 in people who were chronically exposed in a low-to-moderate dose range. The registry of eye pathologies created in the URCRM was used as the basis for the study. Analysis of incidence rates was conducted with account of the individualized doses to the lens. The incidence rates were calculated using the methods of medical statistics per 1,000 people. The odds ration (OR) of cataract development was also evaluated using the case-control study.Results. In total the studied group consisted of 14,751 people (1955–2019) who underwent examinations in the outpatient department of the URCRM. As of December 2020 4,658 patients with cataract were registered. According to the findings of the study (1955–2019) it has been stated that cataract incidence increases with age and thus with the aging of the cohort, improvement of the quality of the diagnosing procedures and examination of the patients. The number of cataracts in women significantly exceeds that in men (3,169 and 1,489, respectively). Standardized incidence rate of cataract over all the years of the follow-up is 172.94 (95 % CI: 168.10–177.78). In the course of the study of the cataract incidence dependence on the dose to the lens, it has been revealed that cataract incidence tends to increase with the increasing dose. Risk value of cataract development (OR) depending on the dose to the lens obtained as a result of the case-control study made up 1.10 (95 % CI: 1.00–1.21).Conclusion. The incidence of cataract in the studied cohort increases with the follow-up periods. The number of cataracts in women is greater than that in men, the age characteristics are approximately the same. A trend of increased effect of the dose on the increase in the risk of cataracts was established based on the results of the performed analysis.

Hysterectomy for benign indication and risk of cataract in women in South Korea

AbstractPurpose: Results from previous studies on the relationship between female reproductive hormones, especially oestrogen, and the incidence of cataracts are limited. This study sought to evaluate the effects of hysterectomy on the risk of lens opacity in Korean women.Methods: This retrospective cohort utilized data collected from 2007 to 2020 from the Korean National Health Insurance database. A total of 255 576 postmenopausal women were included. Participants were divided into those who did and did not undergo hysterectomy. The hysterectomy group was further divided into two subgroups according to the adnexal surgery performed. Comparison of the prevalence of cataract between the control group, hysterectomy alone group, and hysterectomy with adnexal surgery group was performed.Results: The control group included 137 999 participants who did not undergo hysterectomy. The treatment group consisted with 93 719 women who underwent hysterectomy alone or hysterectomy with adnexal surgery. The control group showed a higher incidence of cataracts than the treatment group, as analysed by the 1:1 propensity score matching method and adjusted for variables.Conclusions: All participants in the treatment group had a lower incidence of cataract than those in the control group. These findings may help physicians identify the role of female reproductive hormones in cataract development.

Interaction between postmenopausal hormone therapy and diabetes on cataract.

We investigated whether postmenopausal hormone therapy (HT) use interacts with diabetes, a risk factor for several age-related eye diseases. A cross-sectional analysis of women involved in the Canadian Longitudinal Study on Aging was performed. The random sample comprised of 15,320 community-dwelling women between ages 45 and 85 years old sampled from areas adjacent to 11 data collection centers across Canada. Information on menopausal status and HT were collected by self-report. Data on diabetes and eye disease were obtained by self-report of a physician diagnosis. Multivariable logistic regression was used. After adjusting for demographic, lifestyle, and health variables, a multiplicative interaction was identified such that HT use for 10 years or more was associated with a much higher odds of a report of cataract in women with type 2 diabetes (odds ratio = 2.44, 95% confidence interval 1.49, 3.99) but not in long-term HT users with no diabetes (odds ratio = 1.03, 95% confidence interval 0.87, 1.21) (interaction term P value = 0.013). HT use was not associated with glaucoma or macular degeneration. Long-term HT use and type 2 diabetes interact in their relationship with cataract. This novel finding should be confirmed. If confirmed, women with type 2 diabetes should be informed that long-term HT use increases their risk of cataract. : Video Summary:http://links.lww.com/MENO/A519.

The global state of cataract blindness.

Cataracts are a significant cause of blindness and visual impairment worldwide. The present article reviews the literature and describes the current extent of cataracts globally, barriers to treatment, and recommendations for improving the treatment of cataracts. Prevalence and absolute number of blind because of cataracts remain high, although rates are declining in many areas globally. The age-standardized prevalence of blindness in adults older than 50 remains highest in western sub-Saharan Africa, with a rate of 6.0%. The greatest declines in age-standardized blindness because of cataracts in adults older than 50 between 1990 and 2010 were in East Asia, tropical Latin America, and western Europe. Recent studies have largely found higher rates of cataracts in women than in men. A new simulator for training ophthalmologists in manual small-incision cataract surgery holds promise for the future. The rates of cataract surgery are increasing and postoperative outcomes are improving worldwide, yet challenges to reducing the cataract burden further remain. Cost, an insufficient number of ophthalmologists, and low government funding remain significant barriers but investment in further eye care infrastructure and training of additional ophthalmologists would improve the current situation.

Oestradiol levels and superoxide dismutase activity in age-related cataract: a case-control study.

BackgroundIt has been suggested that the higher prevalence of cataract in women is caused by a withdrawal effect of oestrogen at menopause. In vitro studies have demonstrated protection of serum oestradiol (E2) against oxidative stress through upregulation of antioxidant enzymes, including superoxide dismutase (SOD). The purpose of the present study was to investigate E2 levels and SOD erythrocyte activity in patients with age-related cataract.MethodsThe studied subjects consisted of 103 patients with age-related cataract and 22 controls. Cataracts were classified as nuclear, cortical, or posterior subcapsular. Blood samples were collected and data on smoking, hormonal use, diabetes and age at menarche/menopause was obtained for all individuals. Serum oestradiol analyses were performed with radioimmunoassay (RIA) and SOD activity was measured in erythrocyte lysates.ResultsA negative correlation between age and E2 concentration was seen in a linear regression analysis. No correlation was seen between SOD activity and age or gender and no correlation between E2 levels and SOD activity was found using multiple linear regression. The mean level of E2 for all male subjects was 50.1 ± 16.3 pmol/L, significantly higher compared to 13.8 ± 11.8 pmol/L for postmenopausal women.ConclusionThe present study does not support a role for E2-induced effects on SOD in cataract formation. The findings of higher E2 levels in men than in postmenopausal women may suggest that decreased oestrogen at menopause is partially responsible for the gender-related difference in cataract prevalence. However, the latter can only be verified through prospective randomized trials using hormonal replacement therapy.

Estrogen as an antioxdant in the lens

SummaryFemale gender is a known risk factor for age‐related cataract, although the explanation for this is still largely unknown. We have demonstrated that physiologic concentrations of 17b‐estradiol (E2) protect cultured human lens epithelial cells (HLECs) from oxidative stress induced by H2O2, as evident by decreased production of reactive oxygen species (ROS) and a stabilization of the mitochondrial membrane potential. Total superoxide dismutase (SOD) activity was increased by these concentrations of E2 but no change in gene or protein expression of SOD was seen. In cataract patients and controls, a significant correlation between higher age and decreasing serum levels of E2 was found but no correlation between serum levels of E2 and SOD was demonstrated. Men exhibited higher E2 levels compared to postmenopausal women. To conclude, estrogen seems to exert antioxidative effects on human lens cells, possibly by affecting SOD activity, which may explain the difference in risk of cataract between genders. The finding that men have higher levels of E2 than postmenopausal women further supports the hypothesis that it is the decline in estrogen at menopause that causes the higher risk of cataract in women.

Long-Term Physical Activity and Risk of Age-Related Cataract: A Population-Based Prospective Study of Male and Female Cohorts

To examine the association of total and specific types of physical activity, including walking or bicycling, exercising, work or occupational activity, home or housework, and leisure time inactivity with the risk of age-related cataract in women and men. Population-based prospective cohort study. A total of 52 660 participants (23 853 women and 28 807 men) 45 to 83 years of age from the Swedish Mammography Cohort and the Cohort of Swedish Men. Physical activity was assessed using a self-administered questionnaire at baseline. Cataract diagnosis and extraction were identified through linkage to registers. Incident age-related cataract diagnosis and cataract extraction. During a mean 12.1 years of follow-up (between January 1, 1998, and December 31, 2011; 634 631 person-years), 11 580 incident age-related cataract cases were identified. After adjusting for potential confounders, the highest quartile of total physical activity was statistically significantly associated with 13% decreased risk of cataract compared with the lowest (hazard ratio [HR], 0.87; 95% confidence interval [CI], 0.82-0.92). Walking or bicycling (>60 minutes/day vs. hardly ever; HR, 0.88; 95% CI, 0.82-0.95) and work or occupational activity (heavy manual labor vs. mostly sitting; HR, 0.84; 95% CI, 0.78-0.91) also were associated with decreased risk of cataract. Exercise training and home or housework were not associated with cataract risk. Leisure time inactivity was associated with increased risk of cataract (>6 vs. <1 hours/day; HR, 1.27; 95% CI, 1.07-1.50). The HR for high long-term total physical activity compared with low levels both at 30 years of age and at baseline was 0.76 (95% CI, 0.69-0.85). Our findings indicate that high total physical activity, especially in the long term, and such specific types of physical activity as walking or bicycling and work or occupational activity, may be associated with decreased risk of age-related cataract. Conversely, high inactivity levels may be associated with increased risk of cataract.

Gender Difference in the Association of Metabolic Syndrome and Its Components with Age-Related Cataract: The Korea National Health and Nutrition Examination Survey 2008-2010

PurposeTo explore the relationship of the metabolic syndrome (MetS) and its components with age-related cataract in a representative Korean population.MethodsWe analyzed the data from the Korea National Health and Nutrition Examination Surveys (2008–2010). A total of 11,076 adults (4,811 men and 6,265 women) aged 40 and over who completed ophthalmologic examination were evaluated. Cataract was defined as the presence of cortical, nuclear, anterior (sub)capsular or posterior subcapsular cataract, from slit-lamp examination or previous cataract surgery. MetS was defined according to the Joint Interim Statement proposed in 2009 from the International Diabetes Federation and the American Heart Association/National Heart, Lung, and Blood Institute.ResultsThe prevalence of cataract and MetS in this population was 39.4% (37.1% for men and 41.6% for women) and 38.5% (37.6% for men and 39.4% for women), respectively. Cataract prevalence tended to increase with the number of MetS components in both genders (both P< 0.001). After being controlled for confounders, however, MetS was significantly associated with cataract only in women (adjusted odds ratio (aOR), 1.24; 95% confidence interval (CI), 1.02–1.50]. Reduced HDL cholesterol, elevated fasting glucose, and elevated triglycerides were also significantly associated with cataract in women (aOR, 95% CI; 1.27 (1.07–1.50), 1.23 (1.01–1.50), and 1.26 (1.04–1.52), respectively). In the subgroup analysis for cataract subtype, MetS and reduced HDL cholesterol were significantly associated with nuclear cataract in women (aOR, 95% CI; 1.25 (1.07–1.55) and 1.25 (1.03–1.52), respectively). However, such associations were not found in men.ConclusionsOur results suggest that MetS and its components appear to be associated with age-related cataract only among Korean women, especially in nuclear cataract.

Cumulative Lead Exposure and Age-Related Cataract in Middle-Aged and Elderly Women

Background: Age-related cataract is the leading cause of blindness and visual impairment worldwide, accounting for more than 40% of global blindness. Lead has been proposed as a potentially important risk factor. Possible mechanisms include lead-induced changes in the lens through redox status, glutathione metabolism, lipid peroxidation, post-translational protein modification, and calcium homeostasis. However, only one epidemiologic study has examined the association between cumulative lead exposure and age-related cataract and it was limited to men. Aim: We examined the association of cumulative lead exposure with the risk of age-related cataract in middle-aged and elderly women. Methods: Participants were 502 Boston area participants in the Nurses' Health Study (mean age=63 yrs, range 55-74 yrs) who had lead exposure assessments done in two substudies (bone lead measured in 1993-1995 and 2001-2004), had cataract extraction from 5 years before the bone lead measurement to 2008, and whose cataracts were not congenital or secondary to chronic steroid use, previous intraocular surgery or ocular trauma. We identified cases of cataract extraction by a biennial questionnaire and confirmed all cases with review of medical records. Bone lead levels were measured by K-x-ray fluorescence. We used logistic regression to compute the odds ratio (OR) and 95% confidence interval (CI) for an interquartile range (IQR) increase in bone lead. Results: We identified 48 cases (9.6%) of cataract extraction. After controlling for substudy, age, smoking, and body mass index, neither bone lead measure was associated with cataract (OR=0.80 (95% CI, 0.51, 1.24) for tibia lead (IQR=11 µg/g); OR=0.98 (95% CI, 0.62, 1.53) for patella lead (IQR=13 µg/g). Conclusions: The present study does not support the hypothesis that cumulative lead exposure increases the risk of age-related cataract in women, but further research in larger populations is needed.

High affinity nuclear and nongenomic estradiol binding sites in the human and mouse lens

Estrogen is reported to be protective against cataracts in women and animal models. Immunodetection methods have identified the classic estrogen receptors (ER), ERα and ERβ, in human lens epithelial cells and their RNAs have been detected in the rat and human lens. To verify that estrogen binding occurs in the lens, sensitive [125I]-17β-estradiol binding analyses were performed on subcellular lens fractions from women (ages 39–78 years). The presence of high affinity estradiol binding sites in the nuclear, cytoplasmic, and membrane fractions indicate the lens is able to respond to estrogens, even up to age 78, although fewer binding sites were detected in the postmenopausal women. Additionally, due to the importance of mouse models in estrogen action and lens research, lenses from intact female mice were also analyzed. Both the C57BL/6 and FVB/N mouse strains also possessed high affinity binding sites in all three lens fractions. Furthermore, transcripts for ERα, ERβ, and G protein-coupled estrogen receptor (GPER; previously called GPR30) that bind estradiol with high affinity were expressed in the human and mouse lenses. These data provide the first evidence of GPER expression in the lens. Its role, functions, and subcellular location are currently unknown, but a G-shift assay in the membrane fractions of human and mouse lenses did not show evidence that estradiol induced classic G protein-coupled receptor activation. All three receptor transcripts were also detected in the lens capsule region isolated from female C57BL/6 mice, which is mainly comprised of epithelial cells. In contrast, only ERα and GPER were expressed in the cortex/nuclear region, which is primarily composed of differentiating and organelle-free fiber cells. No significant differences in specific estradiol binding and receptor RNA expression were observed in the lenses between male and female C57BL/6 mice. These findings indicate that the lens is an estrogen target tissue in both sexes. The identification of GPER, in addition to ERα and ERβ, in the lens also adds to the complexity of possible estrogen responses in the lens. Accordingly, the protective effects of estrogen in women and animals may be mediated by all three estrogen receptors in the lens. In addition, the similarities in binding and receptor RNA expression in the lenses of both species suggest that mice can be used to model estrogen action in the human lens.

Lens Opacities in Valencia, Spain

To evaluate the most common lens opacities in Valencia (Spain), analyzed by gender, grade, and type of cataracts. The results are compared with other studies performed at other geographical latitudes and on different races. A total of 1951 eyes of patients diagnosed with cataracts, aged between 30 and 96 years, were evaluated in accordance with age, gender, type and degree of the cataract, bilaterality, and symmetry of this disease. Lens Opacities Classification System III was used to classify the cataract and the degree was graded as mild or moderate to advanced. The most common type of cataract is corticonuclear in the elderly and subcapsular in younger subjects. The most common are nuclear (28.4%) followed by cortical (6.2%), if combined cataracts are ruled out. There is a greater incidence of cortical cataracts in women (70%) and subcapsular cataracts in men (70%). The results suggest the existence of a gender factor in cataract formation and coincide with those obtained in similar studies performed in areas at a similar latitude (40º N) and with different race population. The geographical location (intensity and length of exposure to solar radiation) seems to be a determining factor in the formation of a specific type of cataract, more than race, although there are other factors that contribute in the formation of a specific type of cataract.

Healthy Diets and the Subsequent Prevalence of Nuclear Cataract in Women

To assess the association between healthy diet scores and prevalence of nuclear cataract in women. The association between healthy diet scores, which reflect adherence to the US dietary guidelines, and prevalence of nuclear cataract determined 4 to 7 years later was assessed in a sample of Women's Health Initiative Observational Study participants (aged 50-79 years) residing in Iowa, Wisconsin, and Oregon. Scores on the 1995 Healthy Eating Index, which reflect adherence to 1990 guidelines, were assigned from responses to food frequency questionnaires at the Women's Health Initiative baseline (1994-1998). Presence of nuclear cataract was determined from slitlamp photographs and self-reports of cataract extractions were assessed from May 1, 2001, to January 31, 2004, in 1808 women participating in the Carotenoids in Age-Related Eye Disease Study. Having a high 1995 Healthy Eating Index score was the strongest modifiable predictor of low prevalence of nuclear cataract among numerous risk factors investigated in this sample. The multivariate-adjusted odds ratio for high vs low quintile for diet score was 0.63 (95% confidence interval, 0.43-0.91). Higher prevalence of nuclear cataract was also associated with other modifiable factors (smoking and marked obesity) and nonmodifiable factors (having brown eyes, myopia, and high pulse pressure). Vitamin supplement use was not related to cataract. These data add to the body of evidence suggesting that eating foods rich in a variety of vitamins and minerals may contribute to postponing the occurrence of the most common type of cataract in the United States.

Dietary Carotenoids, Vitamins C and E, and Risk of Cataract in Women

To examine in prospective data the relation between dietary intake of carotenoids and vitamins C and E and the risk of cataract in women. Dietary intake was assessed at baseline in 39,876 female health professionals by using a detailed food frequency questionnaire. A total of 35,551 women provided detailed information on antioxidant nutrient intake from food and supplements and were free of a diagnosis of cataract. The main outcome measure was cataract, defined as an incident, age-related lens opacity responsible for a reduction in best-corrected visual acuity in the worse eye to 20/30 or worse based on self-report confirmed by medical record review. A total of 2031 cases of incident cataract were confirmed during a mean of 10 years of follow-up. Comparing women in the extreme quintiles, the multivariate relative risk of cataract was 0.82 (95% confidence interval, 0.71-0.95; test for trend, P = .04) for lutein/zeaxanthin and 0.86 (95% confidence interval, 0.74-1.00; test for trend, P = .03) for vitamin E from food and supplements. In these prospective observational data from a large cohort of female health professionals, higher dietary intakes of lutein/zeaxanthin and vitamin E from food and supplements were associated with significantly decreased risks of cataract.

Relationship between Reproductive Exposures and Age-Related Cataract in Women

The objective of this study is to evaluate the relationship between reproductive exposures and age-related cataract among women. This was a hospital based case-control study. The study population included female patients, aged 50 years and above who attended the Eye clinic at the University of Malaya Medical Centre. The outcome measurement was based on ophthalmologic examination by an ophthalmologist. The data on exposure was obtained from face to face interview using a structured questionnaire. In order to reduce the recall bias, patients' medical records were used to substantiate the exposure status. Multiple logistic regression was used to assess the association of age-related cataract with exogenous estrogen usage (HRT and OCP) and duration of menses. Important confounders such as age, history of diabetes, cigarette smoking and steroids usage were controlled for in the analysis. Females with 29 years or less of endogenous estrogen exposure of, have almost three times the risk of developing age related cataract (adjusted OR 3.42: 95% CI: 1.28, 9.16), similarly among those with exposure of 30-32 years (adjusted OR 3.64: 95% CI: 1.08, 12.26). Hormone Replacement Therapy used for more than three years was found to be a protective factor of age-related cataract. There is evidence that reproductive exposure may play a role in reducing the occurrence of age-related cataract among Malaysian women.

Frailty and Age-Related Cataract

To determine whether there is an association between age-related cataract and frailty that persists after controlling for visual acuity (VA) and comorbid conditions. Cross-sectional. Two thousand three hundred seventy Beaver Dam Eye Study cohort members at 10-year (third) examination with cataract information. Ninety-nine percent of the population was Caucasian. Medical history, blood pressures, height, weight, measures of frailty, and lens photographs were obtained during the study evaluation. Lens photographs were graded according to standardized protocols. Four of frailty (gait time, peak expiratory flow rate, handgrip strength, chair stand) and an index combining all 4 measures. After controlling for age, age squared, comorbidity index, pack-years, sedentary lifestyle, education, and VA, nuclear cataract in women was not associated significantly with any frailty measures; in men, nuclear cataract was associated with slower gait time (P = 0.01) and a poorer frailty index score (P = 0.01) in multivariable analyses. Cortical cataract was associated in women with a lower peak expiratory flow rate (P<0.01) and in men with weaker handgrip strength (P = 0.02) and a poorer frailty index score (P</=0.01) in multivariable analyses. Posterior subcapsular cataract in women was associated significantly with a lower peak expiratory flow rate (P = 0.01). Nuclear and cortical cataract add significant information in explaining frailty index scores in men. Three common types of age-related cataract are associated with some measures of frailty independent of VA and systemic comorbidities. It is possible that age-related cataract may be an indicator of general functional decline in older adults.

Fruit and vegetable intake and the risk of cataract in women

Prospective data on cataract in relation to total fruit and vegetable intake are limited. We aimed to examine whether higher fruit and vegetable intake reduces the risk of cataract and cataract extraction in a large, prospective cohort of women. Fruit and vegetable intake was assessed at baseline in 1993 among 39 876 female health professionals with the use of a validated, semiquantitative food-frequency questionnaire. A total of 35 724 of these women were free of a diagnosis of cataract at baseline and were followed for incident cataract and cataract extraction. Cataract was defined as an incident, age-related lens opacity responsible for a reduction in best-corrected visual acuity to 20/30 or worse, based on self-report confirmed by medical record review. Individuals, rather than eyes, were the unit of analysis. During an average of 10 y of follow-up, 2067 cataracts and 1315 cataract extractions were confirmed. Compared with women in the lowest quintile of fruit and vegetable intake, women with higher intakes had modest 10-15% reduced risks of cataract (P for trend < 0.05). For cataract extraction, no significant inverse trend was observed (P for trend = 0.12). These prospective data suggest that high intake of fruit and vegetables may have a modest protective effect on cataract.

Case–control study of indoor cooking smoke exposure and cataract in Nepal and India

The prevalence of cataract is higher in developing countries, and in both developed and developing countries more females than males are blind from cataracts. Three epidemiological studies have associated indoor cooking with solid fuels (e.g. wood or dung) and cataract or blindness. However, associations in these studies may have been caused by unmeasured confounding. A hospital-based case-control study was conducted on the Nepal-India border. Cases (n = 206) were women patients, aged 35-75 years with confirmed cataracts. Controls (n = 203), frequency matched by age, were patients attending the refractive error clinic at the same hospital. A standardized questionnaire was administered to all participants. Logistic regression analysis involved adjustment for age, literacy, residential area, ventilation, type of lighting, incense use, and working outside. Compared with using a clean-burning-fuel stove (biogas, LPG, or kerosene), the adjusted odds ratio (OR) for using a flued solid-fuel stove was 1.23 [95% confidence interval (CI) 0.44-3.42], whereas use of an unflued solid-fuel stove had an OR of 1.90 (95% CI 1.00-3.61). Lack of kitchen ventilation was an independent risk factor for cataract (OR 1.96; 95% CI 1.25-3.07). This study provides confirmatory evidence that use of solid fuel in unflued indoor stoves is associated with increased risk of cataract in women who do the cooking. The association is not likely to be due to bias, including confounding, and strengthens the findings of three previous studies. Replacing unflued stoves with flued stoves would greatly reduce this risk, although cooking with cleaner-burning fuels would be the best option.

New Light on Cataracts

Add another ailment to the mischief caused by waning estrogen concentrations. A new study in mice suggests that cataracts are members of the club that already includes osteoporosis, heart disease, cognitive declines, mood swings, and hot flashes (see "More Than a Hot Flash" ). The findings might prod exploration of estrogen as a cataract therapy. The discovery of estrogen receptors in the lens and retina in the late 1990s suggested that the hormone might act in the eye, and epidemiological studies reinforce this notion. After menopause, when estrogen concentrations sink, the incidence of cataracts in women overtakes that in men. Moreover, women taking tamoxifen, a strong estrogen inhibitor, are particularly prone to cataracts. Vicki Davis, an endocrinologist at Cedars-Sinai Medical Center in Los Angeles, was investigating the role of estrogen in bone when she glimpsed its effects on vision. Davis engineered two types of mice by adding mutant estrogen receptor genes and control switches designed to disrupt estrogen's function only in bone. The extra DNA landed in different spots in the two genomes. The control switch Davis employed--a shortened version of one that flicks on a bone-specific gene--misbehaved, and the mice produced the mutant estrogen receptor in many tissues, including the eye. When the females from one strain hit puberty and began producing estrogen, their eyes turned white, indicating that they had cataracts. Littermates without the mutant gene had clear eyes. Intrigued, Davis shifted her focus from bone to eye. Although females of the second strain and males of both strains didn't develop cataracts from naturally occurring estrogen, their eyes turned cloudy after treatment with a potent synthetic version of the hormone diethylstilbestrol (DES). Perhaps individuals of the first strain make more of the mutant receptor than those of the second strain do because the DNA snippet lies in a more active part of the genome, Davis speculates. This situation might explain why females in the second strain require a more robust hormone jolt to provoke cataract formation. Together, the results suggest that estrogen depletion usually encourages cataracts, Davis proposes--even though that model is counterintuitive at first glance. In the animals carrying the altered receptor, estrogen is used to block estrogen signaling, whereas under normal circumstances the hormone activates it. Estrogen receptors pair up when the hormone is present, and the receptor duo then binds to DNA, turning genes on and off. Davis suggests that the mutant receptor can hook up with another receptor, but the team cannot bind its DNA targets, some of which are required to keep the lens clear. Age-related drops in estrogen production also thwart receptor coupling and might have a similar effect. Earlier studies hinted that estrogen is important for lens clarity, says Deborah Carper, who studies mechanisms of cataract formation in the aging eye at the U.S. National Eye Institute in Bethesda, Maryland. But Davis's work provides evidence that blocking estrogen signaling in a live animal can cause cataracts, she says. Already known for its multiple roles, estrogen keeps dazzling onlookers with its versatility. --Bijal P. Trivedi V. L. Davis, C.-C. Chan, T. J. Schoen, J. F. Couse, G. J. Chader, K. S. Korach, An estrogen receptor repressor induces cataract formation in transgenic mice. Proc. Natl. Acad. Sci. U.S.A. , 24 June 2002 [e-pub ahead of print]. [Abstract] [Full Text]

Long-term intake of vitamins and carotenoids and odds of early age-related cortical and posterior subcapsular lens opacities

Proper nutrition appears to protect against cataracts. Few studies have related nutrition to the odds of developing cortical or posterior subcapsular (PSC) cataracts. We assessed the relation between usual nutrient intakes and age-related cortical and PSC lens opacities. We studied 492 nondiabetic women aged 53-73 y from the Nurses' Health Study cohort who were without previously diagnosed cataracts. Usual nutrient intake was calculated as the average intake from 5 food-frequency questionnaires collected over a 13-15-y period before the eye examination. Duration of vitamin supplement use was determined from 7 questionnaires collected during this same period. We defined cortical opacities as grade > or = 0.5 and subcapsular opacities as grade > or =0.3 of the Lens Opacities Classification System III. Some lenses had more than one opacity. No nutrient measure was related to prevalence of opacities in the full sample, but significant interactions were seen between age and vitamin C intake (P = 0.02) for odds of cortical opacities and between smoking status and folate (P = 0.02), alpha-carotene (P = 0.02), beta-carotene (P = 0.005), and total carotenoids (P = 0.02) for odds of PSC opacities. For women aged <60 y, a vitamin C intake > or = 362 mg/d was associated with a 57% lower odds ratio (0.43; 95% CI: 0.2, 0.93) of developing a cortical cataract than was an intake <140 mg/d, and use of vitamin C supplements for > or = 10 y was associated with a 60% lower odds ratio (0.40; 0.18, 0.87) than was no vitamin C supplement use. Prevalence of PSC opacities was related to total carotenoid intake in women who never smoked (P = 0.02). Our results support a role for vitamin C in diminishing the risk of cortical cataracts in women aged <60 y and for carotenoids in diminishing the risk of PSC cataracts in women who have never smoked.