Use of vitamin supplements and cataract: the Blue Mountains Eye Study.

PURPOSE: To investigate relationships between use of vitamin supplements and the three principal cataract types in a population-based sample. METHODS: We studied 2873 of the 3654 participants (79%) aged 49 to 97 years attending the cross-sectional Blue Mountains Eye Study who completed a detailed food frequency questionnaire, which included type, dose, and duration of vitamin supplement use. Masked grading of nuclear, cortical, and posterior subcapsular opacities from lens photographs was performed, using the Wisconsin method. RESULTS: Use of multivitamin supplements was associated with reduced prevalence of nuclear cataract, odds ratio 0.6, 95% confidence interval 0.4 to 1.0, P =.05. For both nuclear and cortical cataract, longer duration of multivitamin use was associated with reduced cataract prevalence (nuclear cataract, trend P =.02; cortical cataract, trend P =.03). Use of thiamin supplements was associated with reduced prevalence of nuclear (odds ratio 0.6, confidence interval 0.4 to 1.0, P =.03, dose trend P =.03) and cortical cataract (odds ratio 0.7, confidence interval 0.5 to 0.9, P =.01, dose trend P =.02). Riboflavin (odds ratio 0.8, confidence interval 0.6 to 1.0, P =.05) and niacin (odds ratio 0.7, confidence interval 0.6 to 1.0, P =.04) supplements exerted a weaker protective influence on cortical cataract. Vitamin A supplements were protective against nuclear cataract (odds ratio 0.4, confidence interval 0.2 to 0.8, P =.01, dose trend P =.01). Folate (odds ratio 0.4, confidence interval 0.2 to 0.9, P =.03) appeared protective for nuclear cataract, whereas both folate (odds ratio 0.6, confidence interval 0.3 to 0.9, P =.01, dose trend P =.04) and vitamin B12 supplements (odds ratio 0.7, confidence interval 0.5 to 1.0, P =.03, dose trend P =.02) were strongly protective against cortical cataract. CONCLUSIONS: Long-term use of multivitamins, B group and vitamin A supplements was associated with reduced prevalence of either nuclear or cortical cataract. A strong protective influence on cortical cataract, from use of folate or vitamin B12 supplements, is a new finding.     

Plasma antioxidant vitamins and carotenoids and age-related cataract.

OBJECTIVE: To investigate the relationships between plasma concentrations of antioxidant vitamins and carotenoids and nuclear, cortical, and posterior subcapsular cataracts in a group of elderly men and women. DESIGN: Cross-sectional survey. PARTICIPANTS: Three hundred seventy-two men and women, aged 66 to 75 years, born and still living in Sheffield, England. METHODS: The Lens Opacities Classification System (LOCS) III was used to grade nuclear, cortical, and posterior subcapsular lens opacities. Fasting blood samples were taken to assess plasma concentrations of vitamin C, vitamin E, alpha-carotene, beta-carotene, lycopene, lutein, zeaxanthin, and beta-cryptoxanthin. MAIN OUTCOME MEASURES: Logistic regression analyses of the associations between plasma vitamin concentrations and cataract subtype, adjusting for age, gender, and other risk factors. RESULTS: After adjustment for age, gender, and other risk factors, risk of nuclear cataract was lowest in people with the highest plasma concentrations of alpha-carotene (odds ratio [OR], 0.5; 95% confidence interval [CI], 0.3-0.9, P for trend 0.006) or beta-carotene (OR, 0.7; 95% CI, 0.4-1.4, P for trend 0.033). Risk of cortical cataract was lowest in people with the highest plasma concentrations of lycopene (OR, 0.4; 95% CI, 0.2-0.8, P for trend 0.003), and risk of posterior subcapsular cataract was lowest in those with higher concentrations of lutein (OR, 0.5; 95% CI, 0.2-1.0, P for trend 0.012). High plasma concentrations of vitamin C, vitamin E, or the carotenoids zeaxanthin and beta-cryptoxanthin were not associated with decreased risk. CONCLUSIONS: These findings suggest that a diet rich in carotenoids may protect against cataract development, but because they are based on observational data, they need to be confirmed in randomized controlled trials.     

Cataract in Central Sri Lanka: Prevalence and Risk Factors from the Kandy Eye Study

Purpose:?To estimate the prevalence of and risk factors for cataracts in the Kandy District of central Sri Lanka.

Methods:?A population-based, cross-sectional ophthalmic survey of the inhabitants of rural villages in central Sri Lanka was conducted; 1375 individuals participated (79.9%; age >/= 40 years, average age 57) and 1318 (95.9%) had an examinable lens in at least one eye. Data collection included district, age, occupation, education level, smoking history, height, weight and dilated lens assessment using Lens Opacities Classification System III grading: nuclear (≥4), cortical (≥2) and posterior subcapsular (≥2) cataracts. Aphakic and pseudophakic eyes were included as operated cataracts for statistical analysis.

Results:?The prevalence of any cataract including operated eyes was 33.1% (95% Confidence Interval (CI), 22.4–43.7%): 26.0% cortical; 7.9% posterior sub-capsular and 4.5% nuclear cataracts. No significant association was found between cataract and gender, smoking or outdoor occupation. Low level of education (secondary or higher vs no education: Odds Ratio (OR) 0.6, CI 0.4-0.9, P?=?0.04) and shorter stature were associated with a higher likelihood of any cataract (OR 1.7, CI 1.1-2.7, P??=?0.02).

Conclusions:?The overall prevalence of cataract in central Sri Lanka is similar to that in other developing Asian regions except for the unusually low prevalence of nuclear cataract. Illiteracy and height appear to be significant predictors for cataract in this population and further investigation is required to explore their influence.     

Associations between plasma levels of vitamins and cataract in the Italian-American Clinical Trial of Nutritional Supplements and Age-Related Cataract (CTNS): CTNS Report #2

PURPOSE: To investigate the association at baseline between plasma levels of selected vitamins and the presence and type of cataract in the participants in The Italian-American Trial of Nutritional Supplements and Age-related Cataract. METHODS: At baseline, the participants (1020, 710 with "early cataract" and 310 with "no cataract," 55-75 years of age) received an ocular examination, photographic lens grading, and measurement of plasma levels of vitamins A, C, E, beta-carotene, and of red blood cell glutathione reductase activity. RESULTS: In multiple logistic models adjusted for potential confounders, high vitamin C levels were associated with a protective effect on nuclear (N) [OR: 0.54; 95% CI: 0.30, 0.97] and posterior subcapsular (PSC) cataract (OR: 0.37; 95% CI: 0.15, 0.93). High vitamin E levels were associated with increased prevalence of cortical cataract (C) (OR: 1.99; 95% CI: 1.02-3.90), PSC (OR: 3.27; 95% CI: 1.34, 7.96) and of any cataract (OR: 1.86; 95% CI: 1.08, 3.18). Conclusions: In agreement with some earlier studies, we found higher plasma levels of vitamin C to be associated with reduced prevalence of N and PSC cataracts. The finding of an increased prevalence of some types of cataract with higher levels of vitamin E was unexpected, has not been previously reported, and could be due to unadjusted confounding.     

A dose–response meta-analysis of dietary lutein and zeaxanthin intake in relation to risk of age-related cataract

Background

Lutein and zeaxanthin are thought to have beneficial effects on protecting the lens against cataract formation, but findings from epidemiologic studies have been inconsistent. We aimed to conduct a meta-analysis of prospective cohort studies to examine the association between dietary lutein and zeaxanthin intake and risk of age-related cataract (ARC).

Methods

We systematically searched MEDLINE, EMBASE, Web of Science, and Cochrane Library databases up to March 2013. Reference lists from retrieved articles were also reviewed. The adjusted relative risks (RRs) from each study were extracted to calculate a pooled estimate with its 95 % confidence interval (CI). The dose–response relationships were assessed by using generalized least-squares trend estimation.

Results

Six prospective cohort studies were identified involving 4,416 cases and 41,999 participants. For the comparison between the highest and the lowest categories of dietary lutein and zeaxanthin intake, significant inverse association were found for nuclear cataract (RR: 0.75; 95 % CI: 0.65, 0.85), but not for cortical cataract (RR: 0.85; 95 % CI: 0.53, 1.17) and for posterior subcapsular cataract (RR: 0.77; 95 % CI: 0.40, 1.13). Dose–response analysis showed that every 300 μg/d increment in dietary lutein and zeaxanthin intake was associated with a 3 %, 1 %, or 3 % reduction in the risk of nuclear cataract (RR: 0.97; 95 % CI: 0.94, 0.99), cortical cataract (RR: 0.99; 95 % CI: 0.95, 1.02), or posterior subcapsular cataract (RR: 0.97; 95 % CI: 0.93, 1.01) respectively.

Conclusions

Dietary lutein and zeaxanthin intake is associated with a reduced risk of ARC, especially nuclear cataract in a dose–response manner, indicating a beneficial effect of lutein and zeaxanthin in ARC prevention.     

Relation of ocular trauma to cortical, nuclear, and posterior subcapsular cataracts: the Beaver Dam Eye Study

BACKGROUND: The consequences of minor ocular trauma in the general population are unclear. The relation of self reported ocular trauma to cortical, nuclear, and posterior subcapsular cataracts is described in a defined population. METHODS: Population based, cross sectional study involving all people aged 43 to 86 years, living in Beaver Dam, Wisconsin (n=4926). Ocular trauma was ascertained by interview and cataract was graded from lens photographs. The relation of ocular trauma to cortical, nuclear, and posterior subcapsular cataracts was examined. RESULTS: People with a history of ocular trauma were more likely to have cortical (odds ratio (OR): 1.5; 95% confidence interval (CI): 1.0 to 2.2) and posterior subcapsular (OR: 1.7; 95% CI: 1.0 to 3.1) cataracts, compared to people without a history of trauma. These associations were stronger for people with previous trauma caused by a blunt object (OR: 3.3; 95% CI: 1.6 to 6.9 for cortical cataract, and OR: 4.1; 95% CI: 1.5 to 10.8 for posterior subcapsular cataracts). However, in analyses comparing the frequencies of cataract between traumatised and non-traumatised eyes among people with unilateral ocular trauma, the ocular trauma association for cortical cataract was no longer present, although the association for posterior subcapsular cataract persisted (OR: 2.4; 95% CI: 0.8 to 7.8). CONCLUSION: The data provide evidence of a possible association between self reported ocular trauma and posterior subcapsular cataract.     

Risk factors for nuclear,cortical and posterior subcapsular cataracts in the Chinese population of Singapore: the Tanjong Pagar Survey

AIM: To describe risk factors for nuclear, cortical, and posterior subcapsular (PSC) cataracts in Chinese Singaporeans. METHODS: A population based cross sectional study was carried out on ethnic Chinese men and women aged 40-81 years. A stratified, clustered, disproportionate (more weights to older people), random sampling procedure was used to initially select 2000 Chinese names of those aged 40-79 years from the 1996 electoral register in the Tanjong Pagar district in Singapore. Eligible subjects (n = 1717) were invited for a standardised ocular examination and interview at a centralised clinic, following which an abbreviated examination was conducted for non-respondents in their homes. Cataract was graded clinically using to the Lens Opacity Classification System (LOCS) III system. The main outcome measures were adjusted odds ratio for risk factors for specific cataract types (nuclear, cortical and PSC), any cataract and cataract surgery, examined in multiple logistic regression models. RESULTS: Out of the 1232 (71.8%) examined, 1206 (70.2%) provided lens data for this analysis. Increasing age was associated with all cataract types, any cataract, and cataract surgery. There was no significant sex difference in presence of any cataract, specific cataract types or cataract surgery. After controlling for age, sex, and other factors, diabetes was associated with cortical cataract (3.1; 95% CI: 1.6 to 6.1), PSC cataract (2.2; 95% CI 1.2 to 4.1), any cataract (2.0; 95% CI: 0.9 to 4.5), and cataract surgery (2.3; 95% CI: 1.3 to 4.1). Lower body mass index was associated with cortical cataract (1.8; 95% CI: 1.1 to 2.9; lowest versus highest quintile) and any cataract (2.3; 95% CI: 1.3 to 4.0). Current cigarette smoking was associated with nuclear cataract (1.7, 95% CI: 1.0 to 2.9; more than 10 cigarettes per day versus none). A non-professional occupation was associated with nuclear cataract (2.9; 95% CI: 1.5 to 5.8; for production or machine operators and 2.6; 95% CI: 1.2 to 5.5; for labourers or agricultural workers, both versus professionals). Lower education was associated with nuclear cataract (2.3; 95% CI: 1.0 to 5.2, none versus tertiary), while lower household income was associated with PSC cataract (4.7, 95% CI: 1.1 to 20.0; income S$4000). CONCLUSIONS: Age related cataracts are associated with a variety of risk factors among Chinese people in Singapore, similar to those reported in European, Indian, and African derived populations. These data support common aetiological mechanisms for age related cataracts, irrespective of ethnic origin.     

Lutein and zeaxanthin and the risk of cataract: the Melbourne visual impairment project

PURPOSE: To evaluate the association of cortical, nuclear, or posterior subcapsular (PSC) cataract with dietary intake of lutein-zeaxanthin (LZ) in a population-based sample. METHODS: For the study, 3271 (83% of the eligible residents) permanent residents aged > or =40 years were recruited in 1992 to 1994 via a cluster random sampling. In 1997 to 1999, 2594 (79%) attended the follow-up examination including lens photography, a life-style questionnaire, and a food-frequency questionnaire (FFQ). Cases were those with cortical opacity > or =4/16, nuclear opacity grade > or =2.0, or PSC opacity > or =1 mm2. Logistic regression was used to calculate the odds ratios for cataract by daily LZ intake, or its quintile indicator with the lowest quintile as the baseline category, controlling for energy-adjusted fat intake and variables previously found to be associated with the cataract outcomes. RESULTS: Of the 2322 participants who attended the follow-up survey and completed the FFQ, 1841 (79%), 1955 (84%), and 1950 (84%) were included in the analyses of cortical, nuclear, and PSC cataract, respectively. There were 182 (9.9%), 387 (19.8%), and 177 (9.1%) cases for cortical, nuclear, and PSC cataract, respectively. Cortical and PSC cataract were not significantly associated with LZ intake. For nuclear cataract the odds ratios were 0.67 (0.46-0.96) and 0.60 (0.40-0.90) for every 1-mg increase in crude and energy-adjusted daily LZ intake, respectively. The odds ratios (95% CI) for those in the top quintile of crude LZ intake was 0.58 (0.37-0.92; P = 0.023 for trend), and it was 0.64 (0.40-1.03) for energy adjusted LZ intake (P = 0.018 for trend). CONCLUSIONS: This study found an inverse association between high dietary LZ intake and prevalence of nuclear cataract.     

Dietary macronutrient intake and five-year incident cataract: the blue mountains eye study

PURPOSE: To investigate the relationships between dietary macronutrient intake at baseline and the five-year incidence of the three main types of cataract in older people. DESIGN: Population-based cohort study. METHODS: Settings: An urban community near Sydney, Australia. STUDY POPULATION: The Blue Mountains Eye Study (BMES) examined 3,654 predominantly Caucasian participants aged 49+ years during 1992 to 1994, and then 2,335 survivors (71.5%) after five years. Of these 2,335 subjects, 1988 (85%) completed a Willett-derived food frequency questionnaire (FFQ) at baseline. OBSERVATION PROCEDURES: A 145-item FFQ was used to assess nutrient intakes and lens photography was used to assess the presence of cataract at both time points. MAIN OUTCOME MEASURES: Incidence of cortical, nuclear, and posterior subcapsular (PSC) cataract was assessed via lens photographic grading following the Wisconsin cataract grading method. RESULTS: After adjusting for multiple known cataract risk factors, higher dietary intakes of omega-3 polyunsaturated fatty acids (n-3 PUFA) were associated with a reduced incidence of nuclear cataract. The odds ratio (OR) for subjects in the highest quintile of intake compared to those in the lowest quintile was 0.58 (95% confidence interval [CI] 0.35 to 0.97), P(trend) = .027. Similarly, for PSC cataract, higher dietary intakes of protein were protective (OR 0.28; 95% CI 0.10 to 0.76), P(trend) = .015. Dietary macronutrient intake was not associated with incident cortical cataract. CONCLUSIONS: Higher dietary intakes of n-3 PUFA may decrease the five-year risk of nuclear cataract, whereas higher dietary intakes of protein may decrease risk for PSC cataract.     

Associations Between Plasma Levels of Vitamins and Cataract in the Italian-American Clinical Trial of Nutritional Supplements and Age-Related Cataract (CTNS): CTNS Report #2

Purpose: To investigate the association at baseline between plasma levels of selected vitamins and the presence and type of cataract in the participants in The Italian-American Trial of Nutritional Supplements and Age-related Cataract. Methods: At baseline, the participants (1020, 710 with “early cataract” and 310 with “no cataract,” 55–75 years of age) received an ocular examination, photographic lens grading, and measurement of plasma levels of vitamins A, C, E, beta-carotene, and of red blood cell glutathione reductase activity. Results: In multiple logistic models adjusted for potential confounders, high vitamin C levels were associated with a protective effect on nuclear (N) [OR: 0.54; 95% CI: 0.30, 0.97] and posterior subcapsular (PSC) cataract (OR: 0.37; 95% CI: 0.15, 0.93). High vitamin E levels were associated with increased prevalence of cortical cataract (C) (OR: 1.99; 95% CI: 1.02–3.90), PSC (OR: 3.27; 95% CI: 1.34, 7.96) and of any cataract (OR: 1.86; 95% CI: 1.08, 3.18). Conclusions: In agreement with some earlier studies, we found higher plasma levels of vitamin C to be associated with reduced prevalence of N and PSC cataracts. The finding of an increased prevalence of some types of cataract with higher levels of vitamin E was unexpected, has not been previously reported, and could be due to unadjusted confounding. The Italian-American Cataract Study Group*     

Refractive associations with cataract: the Blue Mountains Eye Study.

PURPOSE: To assess the relationship between myopia and age-related cataract in a defined older population. METHODS: A cross-sectional study of 3654 people aged 49 to 97 years was conducted in the Blue Mountains near Sydney, Australia, from 1992 through 1994. General medical, eye, and refractive history and information about confounders were collected by questionnaire. Participants had a detailed determination of refraction, and the spherical equivalent refraction of each eye was calculated. The Wisconsin Cataract Grading System was used in masked grading of slit lamp and retroillumination lens photographs, to assess presence and severity of nuclear, cortical, and posterior subcapsular (PSC) cataract. Data from both eyes were analyzed by the generalized estimating equation method, adjusting for cataract risk factors. RESULTS: Included in the analysis were 7308 eyes. A history of wearing distance glasses, excluding eyes with current hyperopic refraction, was used as a proxy for myopia. Subjects who had worn distance glasses were more likely to have nuclear cataract (odds ratio [OR] 1.3; confidence interval [CI] 1.0-2.1). After stratification by age at first wearing distance glasses, this relationship remained only for people who first wore distance glasses after age 40 years (OR 1.3; CI 1.0-1.8), which suggested a myopic refractive shift from developing nuclear opacity and was supported by the weak association found between current myopic refraction and nuclear cataract (OR 1.3; CI 1.0-1.6). Eyes with onset of myopia before age 20 years had the greatest PSC cataract risk (OR 3.9; CI 2.0-7.9). This was supported by the finding of an association between current myopic refraction and PSC cataract (OR 2.5; CI 1.6-4.1). PSC cataract was inversely associated with hyperopia (OR 0.6; CI 0.4-0.9). Refraction-related increasing odds were found between PSC cataract and myopia: low myopia (OR 2.1; CI 1.4-3.5), moderate myopia (OR 3.1; CI 1.6-5.7), and high myopia (OR 5.5; CI 2.8-10.9). High myopia was associated with PSC, cortical, and late nuclear cataract. CONCLUSIONS: Early-onset myopia (before age 20 years) may be a strong and independent risk factor for PSC cataract. The findings suggest the possibility of a dose response between levels of myopia and PSC cataract. Nuclear cataract was associated with presumed acquired myopia, whereas high myopia was associated with all three types of cataract.     

Risk factors for age related cataract in a rural population of southern India: the Aravind Comprehensive Eye Study

AIM: To determine risk factors for lens opacities and age related cataract in an older rural population of southern India. METHODS: A cross sectional population based study of 5150 people aged 40 years and above from 50 clusters from three districts in southern India. The lens was graded and classified after dilation using LOCS III system at the slit lamp for cataract. Definite cataract was defined as nuclear opalescence >/=3.0 and/or cortical cataract >/=3.0 and/or PSC >/=2.0. RESULTS: Definite cataracts were found in 2449 (47.5%) of 5150 subjects and the prevalence of cataract increased with age. The age adjusted prevalence of cataract was significantly lower in males (p = 0.0002). Demographic risk factors-increasing age and illiteracy-were common for the three subtypes of cataract; females were more likely to have cortical cataracts and nuclear cataracts. Additionally, nuclear cataracts were associated with moderate smoking (OR:1.28, 95% CI:1.01 to 1.64), lean body mass indices (OR: 1.37, 95% CI: 1.17 to 1.59) and higher waist to hip ratios (OR: 0.67, 95% CI: 0.54 to 0.82); cortical cataracts with hypertension (OR: 1.39 95% CI:1.11 to 1.72), pseudoexfoliation (OR:1.53,95% CI:1.17 to 2.01), and moderate to heavy smoking; and posterior subcapsular cataracts with diabetes (OR:1.55, 95% CI:1.12 to 2.15), lean body mass (OR:1.32, 95% CI:1.11 to 1.57), and high waist to hip ratios (OR: 0.77, 95% CI: 0.62 to 0.94). CONCLUSIONS: Risk factors for age related cataract in this population do not appear to be different from those reported in other populations. Further studies are required to identify the reason for the high prevalence of age related cataract and to understand better the role of each risk factor for cataractogenesis in this population.     

Topical ocular hypotensive medication and lens opacification: evidence from the ocular hypertension treatment study

PURPOSE: To determine whether topical ocular hypotensive medication is associated with refractive changes, visual symptoms, decreased visual function, or increased lens opacification. DESIGN: Multi-center clinical trial. METHODS: We compared the medication and observation groups of the Ocular Hypertension Treatment Study (OHTS) during 6.3 years of follow-up with regard to the rate of cataract and combined cataract/filtering surgery, and change from baseline in visual function, refraction, and visual symptoms. A one-time assessment of lens opacification was done using the Lens Opacities Classification System III (LOCS III) grading system. RESULTS: An increased rate of cataract extraction and cataract/filtering surgery was found in the medication group (7.6%) compared with the observation group (5.6%) (hazard ratio [HR] 1.56; 95% confidence interval [CI] 1.05 to 2.29). The medication and observation groups did not differ with regard to changes from baseline to June 2002 in Humphrey visual field mean deviation, Humphrey visual field foveal sensitivity, Early Treatment of Diabetic Retinopathy Study (ETDRS) visual acuity, refraction, and visual symptoms. For the medication and observation groups, LOCS III readings were similar for nuclear color, nuclear opalescence, and cortical opacification. There was a borderline higher mean grade for posterior subcapsular opacity in the medication group (0.43 +/- 0.6 SD) compared with the observation group (0.36 +/- 0.6 SD) (P = .07). CONCLUSIONS: We noted an increased rate of cataract extraction and cataract/filtering surgery in the medication group as well as a borderline higher grade of posterior subcapsular opacification in the medication group on LOCS III readings. We found no evidence for a general effect of topical ocular hypotensive medication on lens opacification or visual function.     

Myopia and incident cataract and cataract surgery: the blue mountains eye study

PURPOSE: To assess whether an association exists between myopia and incident cataract and cataract surgery in an older population-based cohort study. METHODS: The Blue Mountains Eye Study examined 3654 participants aged 49 years or more during 1992 to 1994 and then 2334 (75.1%) of the survivors after 5 years. A history of using eyeglasses for clear distance vision was obtained. Objective refraction was performed with an autorefractor, followed by subjective refraction with a logarithm of minimum angle of resolution (logMAR) chart. Emmetropia was defined as a spherical equivalent refraction between +1 D and -1 D, hyperopia as more than +1 D, and myopia as less than -1 D. Slit lamp and retroillumination lens photographs were graded for presence of cortical, nuclear, or posterior subcapsular cataract, according to the Wisconsin Cataract Grading System. Generalized estimating equation models analyzed data by eye. RESULTS: There was a statistically significant association between high myopia (-6 D or less) and incident nuclear cataract (odds ratio [OR] 3.3, 95% confidence interval [CI] 1.5-7.4). Incident posterior subcapsular cataract was associated with any myopia (OR 2.1, 95% CI 1.0-4.8), moderate to high myopia (-3.5 D or less, OR 4.4, 95% CI 1.7-11.5), and use of distance glasses before age 20 (OR 3.0, 95% CI 1.0-9.3), after adjustment for multiple potential confounders, including severity of nuclear opacity. Incident cataract surgery was significantly associated with any myopia (OR 2.1, 95% CI 1.1-4.2) as well as moderate (-3.5 to more than -6D; OR 2.9, 1.2-7.3) and high myopia (OR 3.4, 95% CI 1.0-11.3). CONCLUSIONS: These epidemiologic data provide some evidence of an association between myopia and incident cataract and cataract surgery, after adjustment for multiple confounders and severity of nuclear opacity. These data support other cross-sectional and longitudinal population-based findings.     

The potential role of nutrition on lens pathology: a systematic review and meta-analysis

Oxidative stress is one of the main mechanisms of lens opacification, and certain nutritional antioxidants are suspected to have a protective effect. To examine the role of these nutritional antioxidants on cataract prevention, we searched major databases and reviewed current evidence regarding the protective effect of nutritive antioxidants. We included observational studies that investigate the association between one or more of the following micronutrients and cataract: vitamin A, vitamin C, vitamin E, lutein, zeaxanthin, α- and β-carotene. Two independent authors extracted data and assessed their quality. We pooled results for overall cataract incidence for all types of cataract and separately for nuclear, cortical, and posterior subcapsular cataract. We did not perform sensitivity analysis. Twenty-five studies were included in the qualitative and 24 in the quantitative part of the study, with a total of 295,821 participants over 30 years old. Results from pooled analysis showed a protective effect of antioxidants on cataract, but not all of them reached statistical significance. Statistically significant results were reached for vitamin C (odds ratio [OR] = 0.88, 95% confidence interval [CI] [0.81, 0.97]), beta-carotene (OR = 0.89, 95% CI [0.83, 0.95]), and lutein and zeaxanthin (OR = 0.92, 95% CI [0.85, 0.99]). We did not find statistically significant results for vitamin E (OR = 0.84, 95% CI [0.70, 1.01]), vitamin A (OR = 0.90, 95% CI [0.80, 1.00]), or alpha-carotene (OR = 0.92, 95% CI [0.85, 1.00]). The present study shows a relation between certain antioxidants and cataract, but further studies, especially interventional, are needed to confirm this hypothesis.     

Prevalence of lens opacity in Chinese residents of Singapore: the tanjong pagar survey

OBJECTIVE: To determine the prevalence of lens opacity among Chinese residents of Singapore. DESIGN: Population-based, cross-sectional survey. PARTICIPANTS: Chinese men and women aged 40 years or more in Singapore. METHODS: A stratified, clustered, random sampling method, with more weights given to the older age groups, was used to initially select 2000 Chinese persons aged 40 to 79 years from the 1996 electoral register in the Tanjong Pagar district in Singapore. Eligible subjects (n = 1717) were invited for a comprehensive ocular examination at a centralized clinic, after which nonrespondents were examined in their homes with portable instruments. MAIN OUTCOME MEASURES: Lens opacity, as determined clinically at the slit lamp using a modification of the Lens Opacity Classification System III. Prevalence rates were age adjusted to the 1997 Singapore census population. RESULTS: Of the 1232 persons examined (71.8%), 1206 (70.2%) provided lens data for this analysis. The age-adjusted prevalence of any cataract surgery was 5.1% (95% confidence interval [CI], 3.6, 6.5), with similar rates between men and women. The age-adjusted prevalence of specific types of lens opacity was 22.6% (95% CI, 19.8, 25.4) for any nuclear opacity, 23.9% (95% CI, 21.0, 26.8) for any cortical opacity, and 7.0% (95% CI, 5.3, 8.8) for any posterior subcapsular opacity. The overall age-adjusted prevalence of any cataract or cataract surgery was 34.7% (95% CI, 31.5, 38.0), increasing from 7.0% in those 40 to 49 years and to 94.3% in those 70 years and older (P < 0.001, test for trend for age). When the prevalence of distinct types of lens opacity in an eye was considered, the most common was mixed (age-adjusted prevalence, 11.5%, based on right eye data), followed by nuclear only (9.7%), cortical only (8.3%), and posterior subcapsular only (0.6%). For all cataract types, the prevalence was similar in men and women and was higher in persons examined at their homes than in those examined at the study clinic. CONCLUSIONS: These population-based data suggest that cataract is common among adult Chinese residents in Singapore, despite ready access to cataract surgical services. Persons accepting the offer of free eye examinations were less likely to have cataract than those who did not take up this offer.     

Prevalence of Lens Opacities in Asian Malays

Purpose: To describe the prevalence of lens opacities and cataract surgery in an older Malay population in Singapore.

Methods: The Singapore Malay Eye Study is a population-based cross-sectional study of 3280 (78.7% response rate) Malay adults aged 40–80 years. Participants underwent a standardized clinical eye examination. Digital slit-lamp and retroillumination photographs were taken of both eyes of each participant and graded for age-related nuclear, cortical and posterior subcapsular (PSC) cataract, following the Wisconsin Cataract Grading System. Other lens opacities, including retrodots and vacuoles, were also graded. Information on medical and lifestyle factors was collected using questionnaires. The study sample was directly age-standardized to the Malay population in Singapore using the 2000 Singapore population census.

Results: A total of 3054 (97.7%) and 3113 (99.6%) participants had gradable Topcon slit lamp and Neitz photographs, respectively. The overall age-adjusted prevalence of any cataract was 29.1%, and that of nuclear, cortical and PSC cataract were 12.9% (95% confidence interval, CI, 11.2–13.1%), 21.2% (95% CI 19.8–22.7%) and 9.7% (95% CI 8.8–10.8%), respectively. Age-adjusted prevalence of cataract surgery was 4.7% (95% CI 4.2–5.4%). Prevalence of all three cataract types and cataract surgery increased with age. Age-adjusted prevalence for retrodots and vacuoles were 19.7% (95% CI 18.3–21.1%) and 64.3% (95% CI 61.1–67.6%), respectively. Retrodots were found to be associated with prevalence of all three cataract types, while vacuoles were associated with cortical and PSC cataract prevalence.

Conclusion: Lens opacities were common in this urban Malay population. Retrodots and vacuoles were found to be associated with age-related cataract.     

Refractive errors and incident cataracts: the Beaver Dam Eye Study

PURPOSE: To describe the relation between refractive errors and incident age-related cataracts in a predominantly white US population. METHODS: All persons aged 43 to 84 years of age in Beaver Dam, Wisconsin, were invited for a baseline examination from 1988 through 1990 and a follow-up examination 5 years later from 1993 through 1995. At both examinations, participants had refraction and photographic assessment of cataract, according to a standardized protocol. Myopia was defined as a spherical equivalent of -1.0 diopters (D) or less, hyperopia as +1.0 D or more. The relations between refractive errors at baseline and cataract at baseline (prevalent cataract), 5-year incident cataract, and incident cataract surgery were analyzed by using generalized estimating equations. RESULTS: When age and gender were controlled for, myopia was related to prevalent nuclear cataract (odds ratio [OR], 1.67; 95% confidence interval [CI], 1.23-2.27), but not to cortical and posterior subcapsular cataracts. Myopia was not related to 5-year incident nuclear, cortical, and posterior subcapsular cataracts, but was related to incident cataract surgery (OR 1.89; CI 1.18-3.04). Hyperopia was related to incident nuclear (OR 1.56; CI 1.25-1.95) and possibly cortical (OR 1.25; CI 0.96-1.63) cataracts, but not to posterior subcapsular cataract or cataract surgery. After further adjustment for diabetes, smoking, and education, the association between myopia and incident cataract surgery was attenuated (OR 1.60; CI 0.96-2.64), but the associations between hyperopia and incident nuclear and cortical cataracts were unchanged. CONCLUSIONS: These data support the cross-sectional association between myopia and nuclear cataract seen in other population-based studies, but provide no evidence of a relationship between myopia and 5-year incident cataract. Hyperopia may be related weakly to incident nuclear and cortical cataract.     

Iris color and incident cataract and cataract surgery: the Blue Mountains Eye Study

PURPOSE: To assess whether an association exists between iris color and the incidence of cataract and cataract surgery. DESIGN: Population-based cohort study. METHODS: The Blue Mountains Eye Study examined 3654 predominantly Caucasian participants aged 49+ years during 1992-1994, and then 2335 survivors (75.1%) after 5 years. Iris color was determined by comparison with four standard photographs. Slit-lamp and retro-illumination lens photographs were graded for presence and severity of cortical, nuclear, or posterior subcapsular cataract. Incident cataract surgery was recorded by history and from the photographs. RESULTS: Participants with dark brown iris color had an increased incidence of nuclear cataract, odds ratio (OR) 1.8, 95% confidence interval (CI) 1.2 to 2.8, and cataract surgery (OR, 2.5; CI, 1.4-4.2) in multivariate models, compared with participants with blue iris color. CONCLUSION: Incidence data from this study support previous cross-sectional findings linking dark brown iris color with age-related cataract.     

Prevalence of lens opacities in North India: the INDEYE feasibility study

PURPOSE: To obtain estimates of the prevalence of lens opacities in an Indian setting by using photographically acquired lens images. METHODS: In 11 randomly sampled villages from a rural district of Haryana, North India, 1443 people (median age 60 years), 52% women, were identified from enumeration of the > or =50-year age group; 87% attended an eye examination. Digital images of cortical and posterior subcapsular opacities and photographs of nuclear opacities were graded using the Lens Opacity Classification System (LOCS) II. The prevalence of opacities was based on a grade of 2 or higher in the worse eye for nuclear, cortical, or posterior subcapsular opacities. RESULTS: Of the participants, 1071 people had gradable images; a further 163 had undergone surgery or had dense opacities. Nuclear opacities were the most common type, with an overall prevalence of 56.9% (95% CI, 53.0-60.6). Posterior subcapsular opacities occurred in 20.6% (95% CI, 17.9-25.8) and cortical opacities in 21.6% (95% CI, 17.9-25.8). Prevalence rose steeply with age for all opacities and was higher in the women than in the men for cortical opacities (P = 0.03). The prevalence of any type of lens opacity including surgical cases and dense opacities was 75.3% (95% CI, 71.4-78.81). CONCLUSIONS: These results highlight the substantial excess of lens opacities in India compared with Western populations.