Plasma fibrinogen and other cardiovascular disease risk factors and cataract

Increased risk of peptic ulcer in patients with early-onset cataracts: A nationwide population-based study

Early-onset cataracts (EOC) are associated with an increased inflammatory response; therefore, a potential risk of other inflammatory diseases, like peptic ulcer, may be related. This study investigated the risk of peptic ulcer after being diagnosed with EOC. Retrospective claims data from the Taiwan National Health Insurance Research Database were analyzed. Study subjects comprised patients with EOC (International Classification of Diseases, 9th Revision, Clinical Modification [ICD-9- CM] codes 366.00, 366.01, 366.02, 366.03, 366.04, 366.09, 366.17 and 366.18), aged 20–55 years and newly diagnosed between 2000 and 2010 (n = 1910), and a comparison cohort without the disease (n = 7515). Both cohorts were followed up until 2010 to estimate the incidences of peptic ulcer. We used the Poisson regression model to compare incidence rate ratios and the 95% confidence interval (CI). Cox proportional hazards regression was used to assess the hazard ratio (HR) of peptic ulcer associated with EOC. The overall incidence rate of peptic ulcer was higher in the EOC cohort than in the comparison cohort (10.3 vs 7.68 per 1000 person-years) with an adjusted HR of 1.33 (95% CI = 1.05, 1.69). The present study suggests that patients with EOC are at an increased risk of being diagnosed with peptic ulcer in subsequent years.

Does early onset cataract increase the risk of ischemic stroke? A nationwide retrospective cohort study

This study was attempted to address the association between early onset cataract (EOC) and ischemic stroke. Using the Longitudinal Health Insurance Database 2000, we established an EOC cohort and a comparison cohort by using 4-fold propensity score matching according to age, gender and comorbidities to detect the incidence of ischemic stroke. A Cox model was used to express the risk of ischemic stroke for the EOC patients compared with the comparison cohort. After adjusting for age, gender and comorbidities of hypertension, diabetes mellitus, hyperlipidemia, coronary artery disease, asthma, chronic obstructive pulmonary disease, chronic kidney disease, heart failure, obesity, and atrial fibrillation, the EOC patients had a 1.48-fold higher risk of ischemic stroke than the comparison cohort, but it was not statistically significant. A non-significant increase in the risk of subsequent ischemic stroke development for the EOC patients is demonstrated in this study.

Association Between Cataract and Risk of Incident Atrial Fibrillation: A Nationwide Population-Based Retrospective Cohort Study

OBJECTIVE

To identify the association between cataract and the subsequent atrial fibrillation (AF) risk.

PATIENTS AND METHODS

Our retrospective cohort study was designed to analyze the Longitudinal Health Insurance Database 2000 of the Taiwan National Health Insurance program. We established a cataract cohort (n=39,347) and a noncataract cohort (n=39,347) to observe the incidence of AF. The cataract cohort included patients who were newly diagnosed with cataract from January 1, 2000, to December 31, 2010. Propensity score matching was used to form matched sets of participants with cataract and participants without cataract who share a similar value of propensity score. Univariable and multivariable Cox proportional hazards regression models were used to assess the association between having a cataract and AF.

RESULTS

The median (range) follow-up period was 6.52 years (range, 3.76-9.19 years) and 5.88 years (range, 3.12-8.66 years) for the cataract and noncataract cohorts, respectively; the cumulative incidence curves of AF indicated that the cataract cohort had a significantly higher risk of developing AF than did the noncataract cohort (P<.001). Moreover, the risk of AF was 1.32-fold (95% CI, 1.18-1.48) higher in patients with cataract with surgery and was 1.21-fold (95% CI, 1.06-1.37) higher in patients with cataract without surgery than in patients without cataract.

CONCLUSION

The present study is the first to report that cataract is associated with an increased risk of AF.

Increased risk of ischemic heart disease among subjects with cataracts: A population-based cohort study

BACKGROUND

Association between cataract and the risk of ischemic heart disease (IHD) development is not completely clear.

PURPOSE

The primary aim of the study was to evaluate the association between cataract and the risk of incident IHD. The secondary aim was to investigate the subsequent IHD risk of patients with cataracts undergoing cataract surgery.

METHODS

Retrospective data from the Longitudinal Health Insurance Database 2000 (LHID2000) was analyzed. Study participants were composed of patients with cataracts (International Classification of Diseases, 9th Revision, Clinical Modification [ICD-9-CM] code 366) (n = 32,456), and a comparison cohort without the cataracts (n = 32,456) from 2000 to 2010. Cox proportional hazards regression was used to address the hazard ratio (HR) of IHD associated with cataract.

RESULTS

Within 12 years of follow up, the overall incidence rates of IHD were 24.2 per 1000 person-years in the cataract cohort and 18.2 per 1000 person-years in the noncataract cohort with an adjusted hazard ratio (aHR) of 1.35 (95% CI = 1.29-1.41; P < 0.001). Furthermore, the cataract patients undergoing cataract surgery were associated with a higher risk of IHD compared with those cataract patients without surgery (aHR = 1.07, 95% CI: 1.01-1.14; P < 0.05).

CONCLUSIONS

Our finding suggested that patients with cataracts are at an increased risk of subsequent IHD development.

Cataract increases the risk of peripheral artery occlusive disease: A nationwide population-based cohort study with propensity score

PURPOSE

We conducted this study to evaluate the risk of peripheral artery occlusive disease (PAOD) among patients with cataracts.

METHODS

We analyzed the data from Taiwan National Health Insurance Research Database. Study participants were classified into the cataract group and the non-cataract group between 2000 and 2010. All patients were observed from the index year until PAOD diagnosis, loss to follow up, or the end of 2011. Both study groups were 1:1 matching based upon a propensity score. We used a cox proportional hazards regression model to assess the hazard ratio (HR) and 95% confidence interval (CI) of PAOD for the cataract cohort compared with the non-cataract cohort.

RESULTS

After adjustment for age, sex and comorbidities, the risk of PAOD was significantly higher in the cataract cohort [adjusted HR (aHR)=1.48, 95% CI=1.38-1.58] than the non-cataract cohort.

CONCLUSIONS

We found that patients with cataracts had a 1.48-fold increased risk of developing PAOD compared to the non-cataract patients.

A retrospective study on the outcomes of cataract surgery in an Eastern Regional Health Authority hospital of Trinidad and Tobago

Background. Worldwide, cataract is a major cause of blindness. The paper aims to evaluate factors associated with borderline and poor outcomes of cataract surgery at an Eastern Regional Health Authority (ERHA) hospital in Trinidad and Tobago. Materials and Methods. A hospital-based, retrospective study was done on 401 patients who had undergone cataract surgery (unilateral and bilateral) at an ERHA Hospital between March 2009 and September 2014. Data was collected on variables concerning demographic, medical history, surgical history, ocular findings and visual acuity (VA). The outcome variable of interest was Snellen's post-operative (presenting) VA which was transformed into a dichotomous variable with borderline and poor outcomes as one and good outcomes as the other. Data were analysed using univariate and multivariate logistic regression analyses. Results. Good outcome (presenting VA 6/18 or better) was seen in 350 (67%) eyes. The fitted model consisted of ocular co-morbidity (OR =2.133; 95% CI [1.346-3.380]), hypertension (OR = 0.520; 95% CI [0.381-0.928]), surgical procedure (OR = 1.56; 95% CI [1.004-2.425]), good preoperative VA (OR = 0.388, 95% CI [0.211-0.714]), borderline preoperative VA (OR = 0.485; 95% CI = [0.278-0.843]) and year of first visit to clinic (OR = 2.243; 95% CI [1.215-4.141]). Conclusion. There is a need for community-based outreach to increase awareness of eye health and diseases. It is recommended that the general population is encouraged to take responsibility for personal management. The facilities at the Hospital should also be enhanced.

Hypertension and risk of cataract: a meta-analysis

Background

Cataract is the major cause of blindness across the world. Many epidemiologic studies indicated that hypertension might play an important role in the development of cataract, while others not. We therefore conducted this meta-analysis to determine the relationship between risk of cataract and hypertension.

Methods

Retrieved studies on the association of hypertension with cataract risk were collected from PubMed, Web of Science and the Cochrane Library during June 2014 and were included into the final analysis according to the definite inclusion criteria. Odds ratio (OR) or risk ratio (RR) were pooled with 95% confidence interval (CI) to evaluate the relationship between hypertension and cataract risk. Subgroup analyses were carried out on the basis of cataract type, race and whether studies were adjusted for main components of metabolic syndrome (MS).

Results

The final meta-analysis included 25 studies (9 cohort, 5 case-control and 11 cross-sectional) from 23 articles. The pooled results showed that cataract risk in populations with hypertension significantly increased among cohort studies (RR 1.08; 95% CI: 1.05–1.12) and case-control or cross-sectional studies (OR 1.28; 95% CI: 1.12–1.45). This association was proved to be true among both Mongolians and Caucasians, and the significance was not altered by the adjustment of main components of MS. Subgroup analysis on cataract types indicated that an increased incidence of posterior subcapsular cataract (PSC) resulted among cohort studies (RR 1.22; 95% CI: 1.03–1.46) and cross-sectional/case-control studies (OR 1.23; 95% CI: 1.09–1.39). No association of hypertension with risk of nuclear cataract was found.

Conclusions

The present meta-analysis suggests that hypertension increases the risk of cataract, especially PSC. Further efforts should be made to explore the potential biological mechanisms.

Association between cataract and the degree of obesity

PURPOSE

To investigate the association between the degree of obesity and cataract.

METHODS

We examined 3248 subjects (1421 men and 1827 women) aged 50 years and older who did not have a previous cataract operation. Data were derived from the fourth Korea National Health and Nutrition Examination Survey (2009). Cataract was evaluated by using Lens Opacities Classification System III. Body mass index was categorized into four groups (underweight, <18.5 kg/m(2); normal weight, 18.5 to 22.9 kg/m(2); overweight, 23.0 to 24.9 kg/m(2); and obese, ≥25.0 kg/m(2)). Association between the degree of obesity and cataract was evaluated using logistic regression analyses with adjustments of age, the total pack-years of cigarettes smoked, the amount of pure alcohol (g) consumed per day, daily time spent in vigorous physical activity, diabetes mellitus, sunlight exposure, education level, and income.

RESULTS

Compared with the normal-weight group, the overweight group had significantly lower risk of any type of cataract (odds ratio, 0.70; 95% confidence interval, 0.50 to 0.97) in men and (odds ratio, 0.70; 95% confidence interval, 0.51 to 0.97) in women in the multiple logistic regression analyses. We could not find any unusual lifestyles or metabolic risks for explaining this low cataract prevalence in the overweight groups. However, nutrient intakes (e.g., vitamin B2, niacin, vitamin C, and vitamin A) were highest in the overweight group.

CONCLUSIONS

The overweight group had significantly lower risk of cataract formation than the normal-weight group in Korean population.

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

Purpose

To explore the relationship of the metabolic syndrome (MetS) and its components with age-related cataract in a representative Korean population.

Methods

We 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.

Results

The 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.

Conclusions

Our results suggest that MetS and its components appear to be associated with age-related cataract only among Korean women, especially in nuclear cataract.

Relationship between thyroid dysfunction and chronic kidney disease in community-dwelling older adults

OBJECTIVES

Renal function has been shown to be influenced by thyroid status in animal models and human studies. We aimed to assess the cross-sectional association between thyroid hormones and function with prevalence of chronic kidney diseases (CKD) in older adults.

STUDY DESIGN

1571 Blue Mountains Eye Study participants aged ≥ 60 years were analyzed in 2002-4. Thyroid dysfunction was defined using serum thyrotropin (TSH) screen, followed by serum free T4 (FT4) assessment. Baseline biochemistry including serum creatinine was measured. Moderate CKD was defined as estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m(2).

RESULTS

After adjusting for age, sex, receipt of pension payment, body mass index, smoking, hypertension and diabetes, persons with any thyroid dysfunction (hyperthyroidism or hypothyroidism) had 84% higher likelihood of having CKD, odds ratio, OR, 1.84 (95% confidence intervals, CI, 1.03-3.31). Participants in the highest versus lowest quartile (reference) of serum TSH and FT4 had a significantly greater odds of prevalent CKD, OR 1.82 (95% CI 1.22-2.71), and OR 1.64 (95% CI 1.10-2.45), respectively. Similarly, among participants not receiving treatment for their thyroid dysfunction (n=1329), those in the third and fourth quartiles of serum TSH had significantly greater odds of having prevalent CKD, OR 1.83 (95% CI 1.15-2.92) and OR 1.96 (95% CI 1.23-3.13), respectively, Ptrend=0.001. Significant associations were not observed between type of thyroid dysfunction (hyperthyroidism or hypothyroidism) and prevalent CKD.

CONCLUSIONS

Increasing serum TSH was associated with a greater likelihood of prevalent CKD among older adults, independent of the influence of age, diabetes and hypertension.

Is cataract associated with cardiovascular morbidity?

AIMS

To evaluate the prevalence of cardiovascular disease (CVD) and its risk factors among patients undergoing cataract surgery.

METHODS

A retrospective observational case-control study of all the members older than 50 years who underwent cataract surgery in the Central District of Clalit Health Services in Israel (years 2000-2007) (n=12,984) and 25, 968 age- and gender-matched controls. We calculated the prevalence of CVDs' and their risk factors, including carotid artery disease (CAD), peripheral vascular disease (PVD), systemic arterial hypertension (HTN), chronic renal failure (CRF), ischaemic heart disease (IHD), congestive heart failure, diabetes, smoking, alcohol abuse, and hyperlipidaemia. The main outcome measures were the odds ratio of having CVDs among cataract patients undergoing surgery compared with controls.

RESULTS

No difference was found in demographics (age, gender, marriage status, socioeconomic class, and living place) between the study and control groups. All CVDs' risk factors were significantly more prevalent in cataract patients in univariate analysis. Multivariate logistic regression analysis revealed a significant association of the following with cataractogenesis: diabetes, CAD, HTN, PVD, smoking, IHD, CRF, hyperlipidaemia, and Ashkenazi origin.

CONCLUSIONS

CVDs and their risk factors are more prevalent among cataract patients undergoing cataract surgery.

Influence of diabetes and cardiovascular disease on the long-term incidence of cataract: the Blue Mountains eye study

PURPOSE

To assess associations between diabetes and selected cardiovascular risk factors and long-term incident cataract and cataract surgery.

METHODS

A cohort of initially 3654 elderly Australians were followed over a period of 10 years. Questionnaires ascertained relevant history and fasting blood samples were taken. Impaired fasting glucose (IFG) and metabolic syndrome were defined using World Health Organization criteria. Discrete logistic models were used to assess risk of incident cataract.

RESULTS

After controlling for age, sex, and other factors, baseline diabetes predicted nuclear cataract (relative risk, RR, 1.64; 95% confidence interval (CI), 1.02-2.64) and IFG predicted cortical cataract (RR, 2.01; CI, 1.20-3.36). Each standard deviation (SD) increase in glucose was positively associated with cortical cataract (RR, 1.13; CI, 1.01-1.27). Higher body mass index (BMI) was positively associated with posterior subcapsular cataract (RR per SD, 1.20; CI, 1.03-1.41). Persons using anti-hypertensive medication had a higher incidence of cataract surgery (RR, 1.61; CI, 1.18-2.20). Metabolic syndrome was associated with an increased risk of all 3 cataract subtypes. Few other significant associations were found between cardiovascular disease, cardiovascular risk factors, and incident cataract or cataract surgery.

CONCLUSIONS

We confirmed diabetes as a risk factor for age-related cataract and IFG as a possible risk factor for cortical cataract. BMI and hypertension were also related to incident cataract. Overall, few associations were found between cardiovascular risk factors and long-term incident cataract. A cluster of metabolic abnormalities attributable to insulin resistance appears more likely to contribute to cataract formation than any individual cardiovascular risk factor alone.

Relation between cataract and metabolic syndrome and its components

PURPOSE

To estimate the prevalence of cataract in the middle-aged urban population and the relation between cataract and metabolic syndrome and metabolic syndrome components.

METHODS

The survey was carried out in Kaunas City, Lithuania, from 2001 to 2002, according to WHO MONICA study protocol. The ophthalmologic investigation was performed for 1282 respondents (573 men and 709 women) aged 35-64 years. Cataract was defined at slit lamp using LOCS III method. Metabolic syndrome was defined by ATP III criteria.

RESULTS

Cataract was found in 17.6% of men and 19.0% of women (p>0.05). Metabolic syndrome was detected in 19.5% of men and 25.7% of women (p<0.05). After distribution of persons into 10-year age groups (35-44, 45-54, 55-64), the prevalence of cataract and metabolic syndrome among men and women significantly increased with age. A relation between cataract and metabolic syndrome was found for men aged 55-64 years and for women aged 45-64 years: the prevalence of cataract in men with metabolic syndrome was 1.3 times higher (43.8% vs 32.9%; OR=1.59 [95% CI, 0.77-3.26]) and in women with metabolic syndrome 1.4 times higher (31.8% vs. 22.6%; OR=1.60 [95% CI, 1.03-2.49]) than in persons of the same age and sex without metabolic syndrome. For men aged 4-64 years cataract was significantly related to central obesity (OR=1.80 [95% CI, 1.01-3.20]) and for women aged 45-64 years cataract was significantly related to higher arterial pressure (OR=1.98 [95% CI, 1.21-3.25]), central obesity (OR=1.54 [95% CI, 1.01-2.35]), and elevated level of serum triglycerides (OR=1.86 [95% CI, 1.20-2.90]).

CONCLUSIONS

The results of this study show that the prevalence of cataract in urban women 45-64 years of age with metabolic syndrome was significantly higher than in women of this age without metabolic syndrome.

Prevalence of thyroid disease in an older Australian population

AIM

To determine the prevalence of thyroid disease in an older Australian population in a population-based cross-sectional study.

BACKGROUND

Community-living subjects, aged 49 years or older, in two Blue Mountains postcodes were invited to participate in an eye, nutrition and health study between 1997 and 2000.

METHODS

Three thousand five hundred and nine of the 4489 identified persons participated. Fifty-seven per cent of 3504 who completed questionnaires were women; their mean age was 66.8 years. Thyroid-stimulating hormone (TSH) was measured in 2665 subjects (76% of those completing the questionnaire). The main outcome measures were serum TSH and free thyroxine levels, serum lipids, urate and sugar levels and questionnaire responses.

RESULTS

The prevalence of recognized thyroid disease (either self-reported history of thyroid disease or current thyroxine treatment) was 10% (95% confidence interval (CI) 8.9-11.1%). An additional 3.6% (95%CI 2.9-4.3%) of participants had unrecognized thyroid disease (abnormal TSH). The TSH was abnormal in 7.1% (95%CI 5.8-8.4%) of women and 3.7% (95%CI 2.6-4.8%) of men. Sixty-five per cent of those with an abnormal TSH did not report a history of thyroid disease, whereas 25% of those taking thyroxine replacement therapy had an abnormal TSH level. The prevalence of hypothyroidism increased with increasing age in women. The mean fasting cholesterol was 0.36 mmol/L (95%CI 0.15-0.57) higher in hypothyroid subjects than in euthyroid subjects.

CONCLUSION

Thyroid disease in older Australian women is relatively common and may be undiagnosed. Ongoing monitoring of patients on thyroxine replacement therapy is important, given that 25% of treated patients had an abnormal TSH.

Obesity and eye diseases

The prevalence of obesity has reached epidemic proportions in many countries. Although its impact on overall health is well documented, less is known about the ocular manifestations of obesity. Among different eye diseases, obesity has been linked with age-related cataract, glaucoma, age-related maculopathy, and diabetic retinopathy. Numerous population-based and prospective studies support an association between obesity and risk of age-related cataract. However, the nature and strength of these associations, particularly with the different cataract subtypes, remains to be determined. There is strong evidence that obesity is associated with elevated intraocular pressure, but there is no convincing data to support a more direct association between obesity and glaucomatous optic neuropathy. Studies to date have not found a consistent pattern of association between obesity and risk of age-related maculopathy or diabetic retinopathy. Thus, although obesity may be a risk factor for many ocular conditions, the present literature is inadequate to establish any convincing associations. Furthermore, whether weight loss reduces the risk of eye diseases remains unresolved. Because of the potential public health impact of obesity, there is a greater need to understand its ocular effects.

Risk factors for cataract subtypes waterclefts and retrodots: two case–control studies

Waterclefts and retrodots are independently associated with visual impairment, yet a review identified no data on risk factors.

PURPOSE

To investigate risk factors for these two human lens cataract subtypes.

METHOD

Two nested case-control studies: The host study comprised 1078 subjects (55 years) attending the Somerset and Avon Eye Study (SAES). In total, 197 watercleft cases (Oxford grade 0.2 in either eye) and 199 retrodot cases (Oxford grade 1.0 in either eye) were individually age/gender matched to controls. Detailed ophthalmic and potential risk factor data were collected, including body mass index (BMI), smoking, alcohol, diabetes, hypertension, analgesics, vitamin supplementation, nutrition, sunlight exposure, dehydration, hormonal (women), blood lipids, glucose, urea, creatinine, uric acid, and vitamin levels.

RESULTS

For waterclefts, univariable analysis identified BMI, alcohol intake, vitamin status, sunlight, urea, creatinine, and uric acid as possible risk factors. Multivariable analysis identified two independent associations. Total number of 'any' analgesics in the previous year: adjusted P<0.01 (U-shaped risk profile, unadjusted high vs medium use (=reference) OR 2.39, 95% CI 1.35-4.26 with medium use vs none (=reference) OR 0.43, 95% CI 0.26-0.72); total sunlight: adjusted P=0.03 (unadjusted highest exposure vs lowest (=reference) OR 3.25, 95% CI 1.11-9.50). For retrodots, univariable analysis identified alcohol, HRT, and lipids. Multivariable analysis identified two independent associations. Mean number of alcohol units consumed per month, adjusted P=0.02 and HDL cholesterol levels, adjusted P=0.02 (unadjusted ORs NS both).

CONCLUSION

This is the first available published information on risk factors for the human cataractous lens features waterclefts and retrodots.

Is renal impairment a predictor of the incidence of cataract or cataract surgery?

PURPOSE

To explore the relationship between creatinine clearance, an estimate of glomerular filtration rate, and 5-year incidence of cataract and cataract surgery.

DESIGN

Population-based cohort study.

PARTICIPANTS

Of the 3654 participants (aged 49 years or older) of the Blue Mountains Eye Study (BMES I) baseline examination (during 1992 to 1994), 2334 (75%) were reexamined after 5 years from 1997 to 1999 (BMES II).

METHOD

Risk factor data were collected for all participants at baseline (BMES I). Assessment of renal function was based on estimated creatinine clearance (C(Cr)) calculated with the Cockcroft-Gault formula, adjusted for body surface area, and expressed in ml/minute/1.73 m2. Cataract incidence was determined from graded photographs. The association between renal function and incidence of cataract and cataract surgery was analyzed by logistic regression.

MAIN OUTCOME MEASURES

Incidence of nuclear, cortical, and posterior subcapsular cataract, and cataract surgery.

RESULTS

Mean C(Cr) +/- standard deviation was 60+/-13 ml/minute/1.73 m2. The overall 5-year incidence of nuclear, cortical, and posterior subcapsular cataract was 35.7% (417 of 1167 participants at risk), 16.7% (274 of 1641), and 4.3% (77 of 1790), respectively. Cataract surgery was performed in 6.8% (144 of 2123) of participants. There were no significant associations of renal function with incident nuclear (odds ratio [OR], 1.0; 95% confidence interval [CI], 0.99-1.02), cortical (OR, 1.0; CI, 0.98-1.01), and posterior subcapsular cataract (OR, 1.0; CI, 0.99-1.04) after adjusting for multiple risk factors. After adjusting for age, gender, and dark brown iris color, moderate or worse renal impairment (C(Cr) <60 ml/minute/1.73 m2) compared with normal or mildly impaired function (C(Cr) > or =60 ml/minute/1.73 m2) was significantly associated with incident cataract surgery (P<0.05), but the effect depended on age. Participants younger than 60 years of age with moderate to severe renal impairment had increased odds of incident cataract surgery (OR, 2.75; CI, 1.06-7.14), but this OR decreased with age. In participants 80 years old or older, the OR was 0.34 (CI, 0.11-1.10).

CONCLUSIONS

There were no significant effects of renal function on the incidence of cataract of any type. The effect of moderate or worse renal impairment on incident cataract surgery depended on age. However, the interpretation of this effect is uncertain because of additional factors that may be involved in patients having surgery.

Cardiovascular disease, vascular risk factors and the incidence of cataract and cataract surgery: the Blue Mountains Eye Study

PURPOSE

To assess whether an association exists between cardiovascular disease, vascular risk factors and incident cataract and cataract surgery.

METHODS

The Blue Mountains Eye Study examined 3654 participants > or = 49 years of age during 1992-4, then 2335 survivors (75.1%) after five years. Trained interviewers administered a vascular history questionnaire; height, weight and blood pressure were measured. Lens photographs from both examinations were graded for presence of cortical, nuclear or posterior subcapsular cataract.

RESULTS

Obesity (body mass index > or = 30 kg/m2) was significantly associated with increased incidence of both cortical [odds ratio (OR) 1.6, 95% confidence interval (CI) 1.2-2.2] and posterior subcapsular cataract (OR 2.1, CI 1.2-3.7). Hypertensive participants using medication and aged less than 65 years at baseline had a higher incidence of posterior subcapsular cataract (OR 3.4, 95% CI 1.3-8.4) than normotensive subjects. A history of angina was associated with higher cataract surgery incidence (OR 2.1, 95% CI 1.3-3-5).

CONCLUSIONS

These longitudinal data provide some evidence supporting a relationship between cardiovascular disease, vascular risk factors and incident cataract and cataract surgery. The findings confirm a number of associations previously documented in cross-sectional data.

Serum lipids and age-related lens opacities: a longitudinal investigation: the Framingham Studies

OBJECTIVE

To investigate whether serum lipid/lipoprotein levels are independent risk factors for nuclear, cortical, or posterior subcapsular (PSC) cataracts.

DESIGN

Case-control study nested in a cohort study.

PARTICIPANTS AND METHODS

Eye examinations were conducted on surviving members of the Framingham Offspring Heart Study cohort from 1989 to 1991 (Framingham Offspring Eye Study) to determine cataract case-control status. Data from the Framingham Offspring Heart Study, including fasting serum total cholesterol, high-density lipoprotein cholesterol, and triglyceride measurements collected first in 1971, again approximately 8 years later, and approximately every 4 years thereafter were used to examine associations between lipid levels (mean levels across examinations and slope of measurements over time) and the presence of specific cataract types. The multistage analyses included 1869 persons aged 45 years and older.

MAIN OUTCOME MEASURES

A standardized grading system was used to grade cortical, nuclear, and PSC cataracts.

RESULTS

The median age of participants was 55 years; 49% were males. In multivariable logistic regression models adjusted for potential confounders, fasting hypertriglyceridemia (>/=250 mg/dl) was associated with an increased risk of PSC cataract in men (P = 0.02). High-density lipoprotein cholesterol levels </=35 mg/dl were associated with PSC cataract in men at a borderline level of significance (P = 0.09). No associations were noted between serum lipid/lipoprotein variables and risk of cortical or nuclear cataract.

CONCLUSIONS

These findings suggest that hypertriglyceridemia, a potentially modifiable factor, is associated with the development of PSC cataract in men.

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

BACKGROUND

Obesity may influence several physiologic processes involved in cataract formation such as oxidative stress, glycosylation and osmotic stress.

OBJECTIVE

To examine the association between increased body mass index (BMI) and the incidence of cataract extraction.

DESIGN AND SETTING

The Nurses' Health Study and the Health Professionals Follow-up Study, both prospective cohort studies of US women and men.

SUBJECTS

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).

MEASUREMENTS

Cataract extractions occurring between baseline and 1996, confirmed by medical records.

RESULTS

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.

CONCLUSION

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.

Cataract in the 21st Century: lessons from previous epidemiological research

BACKGROUND

Cataract surgery is currently the most commonly performed ophthalmic procedure in Australia. The purpose of this paper is to review Australian data on cataract prevalence and risk factors and to project potential future demand for cataract services.

METHODS

Age- and gender-specific cataract prevalence data from the Melbourne Visual Impairment Project (VIP) and the Blue Mountains Eye Study (BMES) were applied to population estimates from the Australian Bureau of Statistics. Published cataract risk factor data from the two studies were reviewed.

RESULTS

Although the projected number of cataracts varies substantially based on the definition used, the relative number of cataracts will double over the next 50 years due to the aging of the population. Risk factors for cortical cataract identified in both the VIP and the BMES included female gender, sunlight exposure and myopia. Concordant findings for nuclear cataract included female gender, brown irides, cigarette smoking and myopia. The only risk factor for posterior subcapsular cataract (PSC) that was identified in both studies was myopia. Some of the discrepant findings between the two studies included alcohol intake, diabetes and medication use.

DISCUSSION

These data suggest that supply and demand for cataract surgery must be considered and managed to maintain the current level of cataract surgery delivery as the number of people with cataract increases at a proportionately greater rate than the total population. The supply of cataract surgical services could be increased through an increase in the number of ophthalmologists, an increase in the efficiency with which cataract surgical services are delivered, or improved technology. The demand for cataract surgery could be decreased through the implementation of effective primary prevention strategies, although successful strategies are currently unknown and/or untested. Given our current state of knowledge about cataract, it seems most feasible immediately to alter the health service delivery side of the equation to reduce the public health burden of cataract.

Lower nasal distribution of cortical cataract: the Blue Mountains Eye Study

Previous reports have indicated that cortical cataract commences in the lower nasal lens, possibly due to sunlight exposure because of the shallow brow temporally. The present study aimed to assess the lens sector distribution of cortcal cataract in a population. The Blue Mountains Eye Study assessed 3654 residents aged 49-97 years; 3270 phakic subjects had retroillumination lens photographs graded using the Wisconsin method, which divides the lens into eight radial sectors with a grid overlay. Graders estimated percentage of cortical opacity in each sector. The lower nasal area consistently had the greatest opacity, a pattern present at each age and similar in both sexes, despite the 20% greater cortical cataract in women. The mean area of lens cortex involved by opacities in the lower nasal hemisphere was four fold greater than in the upper temporal hemisphere at each age. The lower nasal distributon was highly symmetrical when both eyes were affected. When > 20% of the lower nasal lens quadrant had cortical opacity, 88% of bilaterally affected subjects had cortical cataract n the same quadrant of the fellow eye. The lower nasal distribution may indicate a role for sunlight in the aetiology of cortcal cataract, which could be considered when examining other cortical cataract risk factors, such as diabetes, vascular disease and hormonal factors in women.