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.     

Incidence of age-related cataract over a 10-year interval: the Beaver Dam Eye Study

OBJECTIVE OR PURPOSE: To describe the cumulative incidence of age-related cataracts and cataract surgery over a 10-year interval. DESIGN: Prospective epidemiologic study. PARTICIPANTS: Persons 43 to 86 years of age participating in the Beaver Dam Eye Study (n = 4926 at baseline, 2764 for baseline, 5-year and 10-year follow-ups). METHODS: Questionnaires and examinations were performed according to standardized protocols in a clinic setting in the town of Beaver Dam, Wisconsin. Lens photographs were obtained with specially modified cameras and were graded according to codified rules by trained graders. MAIN OUTCOME MEASURES: Nuclear, cortical, and posterior subcapsular cataracts and cataract surgery. RESULTS: In right eyes, incident nuclear cataract occurred in 19.4%, cortical cataract in 17.4%, posterior subcapsular cataract in 6.1%, and cataract surgery in 10.8%. Incidence increased for all end points with age. Women had significantly higher incidences of nuclear cataract and cataract surgery than men. Time trends seem to be influencing the incidence of cataract surgery. CONCLUSIONS: Age-related cataracts are common events in aging. Age-specific cataract surgery incidence seems to be increasing.     

Nine-year refractive changes in the Barbados Eye Studies

PURPOSE: To describe 9-year changes in refractive errors and estimate incidence of myopia and hyperopia in adults of African-descent, along with associated risk factors. METHODS: The 9-year follow-up of the Barbados Eye Studies (1997-2003) reexamined 2793 surviving cohort members (81% participation). Refractive errors were determined by automated refraction. Myopia/hyperopia were defined as spherical equivalent < -0.5 diopters (D)/> +0.5 D, and the cutoff for moderate-high myopia/hyperopia was 3.0 D. Incidence rates of myopia/hyperopia were estimated by the product-limit approach, based on eyes without such conditions at baseline. Risk factors were evaluated by logistic regression in discrete time hazard models. RESULTS: Nine-year refraction changes varied by age. Persons aged 40 to 49 years experienced hyperopic shifts (median, +0.38 D), whereas persons > or =60 years had myopic shifts (median, -0.75D). Overall 9-year incidence was 12.0% for myopia and 29.5% for hyperopia; rates were 3.6% and 2.0% for moderate-high myopia and hyperopia, respectively. Myopia risk increased with age, baseline nuclear lens opacities (risk ratio [RR] = 1.7; 95% confidence interval [CI]: 1.01-2.9), glaucoma (RR = 6.0, 95% CI: 3.9-9.3), and ocular hypertension (RR = 2.0, 95% CI: 1.3-3.0), while cortical lens opacities decreased risk (RR = 0.6, 95% CI: 0.4-0.9). Incidence of moderate-high myopia was also related to baseline age, nuclear opacities, glaucoma, male gender (RR = 1.7, 95% CI: 1.0-2.8), and diabetes history (RR = 1.9, 95% CI: 1.01-3.5). Hyperopia risk decreased with older age, male gender, and glaucoma diagnosis. CONCLUSIONS: Refractive errors continue to develop frequently in older adults. Nuclear lens opacities, glaucoma, and diabetes increase the risk of older-onset myopia, a result of public health relevance to this and similar African-origin populations.     

Five-year incidence of cataract in older persons with diabetes and pre-diabetes

PURPOSE: To investigate longitudinal associations between diabetes and the 5-year incidence of cataract and cataract surgery. (A population-based, cohort study of 2335 persons with baseline ages 49 years or older resident in the Blue Mountains region, west of Sydney, Australia). METHODS: Baseline information on diabetes history was collected during an interviewer-administered questionnaire. Impaired Fasting Glucose (IFG) was defined as venous plasma glucose between 6.0 and 7.0 mmol/L and newly diagnosed diabetes as plasma glucose >7.0 mmol/L, using fasting blood glucose measurements taken at baseline. Retroillumination lens photographs from the baseline and 5-year follow-up examinations were graded for presence of cortical, posterior subcapsular (PSC) and nuclear cataract. RESULTS: We found a 2-fold higher 5-year incidence of cortical cataract in participants with IFG, multivariate adjusted odds ratio (OR) 2.2, 95% confidence interval (CI) 1.1-4.1. Incident PSC cataract was more frequent among persons with diabetes, but this association was statistically significant only for those with newly diagnosed diabetes, multivariate adjusted OR 4.5 (CI 1.5-13.0). There were no statistically significant associations found between incident nuclear cataract or cataract surgery and either diabetes or IFG. CONCLUSIONS: These epidemiological data suggest that IFG, a pre-diabetic condition, may be a risk factor for the development of cortical cataract.     

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.     

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 =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 =30kg/m 2 ) 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.     

Refractive errors,intraocular pressure,and glaucoma in a white population

OBJECTIVE: To examine the relation of refractive errors to glaucoma and intraocular pressure (IOP) in a defined white population. DESIGN: Population-based cross-sectional and follow-up study. PARTICIPANTS: Persons aged 43 to 86 years living in Beaver Dam, Wisconsin (n = 4926). METHODS: All participants received a standardized assessment of refraction, IOP, and glaucoma at baseline (1988-1990), with IOP remeasured 5 years later (1993-1995). Refraction was defined at baseline as follows: myopia as spherical equivalent of -1.00 diopters (D) or less, emmetropia as -0.75 to +0.75 D, and hyperopia as +1.00 D or more. MAIN OUTCOME MEASURES: Relation of baseline refraction to prevalent glaucoma (defined from IOP, optic disc, and visual field criteria) and incident ocular hypertension (defined as IOP more than 21 mmHg at the 5-year examination in eyes with IOP of 21 mmHg or less at baseline). RESULTS: A myopic refraction was correlated with increasing IOP at baseline (P < 0.001). After controlling for age and gender, persons with myopia were 60% more likely to have prevalent glaucoma than those with emmetropia (odds ratio [OR], 1.6; 95% confidence interval [CI], 1.1, 2.3). In contrast, controlling for age, gender, and baseline IOP, persons with hyperopia were 40% more likely to have incident ocular hypertension than those who were emmetropic at baseline (OR, 1.4; 95% CI, 1.0, 2.0). Myopia was not related to incident ocular hypertension. CONCLUSIONS: In these population-based data, there was a cross-sectional association of myopia with higher IOP and prevalent glaucoma. Similar associations have been found in previous studies. Hyperopia may be associated with 5-year risk of ocular hypertension, a finding that needs further investigation.     

Incident cataract after a five-year interval and lifestyle factors: The Beaver Dam Eye Study

CONTEXT: A population-based study to investigate risk factors for age-related eye disease was begun in 1987 in a representative American community. Incidence of cataract was subsequently evaluated. SPECIFIC OBJECTIVES: To examine the relationships of cigarette smoking, alcohol, and caffeine intakes to incidence of age-related cataracts five years later. DESIGN: Observational epidemiologic incidence study of an adult population. PARTICIPANTS AND INTERVENTION: Adults 43-84 years of age were identified during a census in 1987-1988, and examined at baseline (1988-1990) and after a five-year interval (1993-1995). MAIN OUTCOME MEASURE: Standardized protocols were used at the baseline and follow-up evaluations for exposures and for objective identification of cataracts. RESULTS: Cumulative incidence of nuclear cataract in right eyes was about 12%, cortical cataract about 8%, and posterior subcapsular cataract about 3%. In multivariable analyses of the general estimating equations type, there were significant associations between nuclear cataract and: pack-years smoked (odds ratio [OR] 1.05, 95% confidence interval [CI] 1.01, 1.09 per 10 pack-years); and current alcohol intake (OR 1.01, 95% CI 1.00, 1.02 per 10 grams ethanol/week). Cigarette smokers were more likely to have had cataract surgery in the interval between baseline and follow-up examinations. CONCLUSIONS: Cigarette smoking and alcohol consumption were associated with modestly increased risks of incident nuclear cataract over a five-year interval.     

Diabetes, cardiovascular disease, selected cardiovascular disease risk factors, and the 5-year incidence of age-related cataract and progression of lens opacities: the beaver dam eye study

PURPOSE: To describe the relationships of diabetes mellitus, cardiovascular disease, and selected cardiovascular disease risk factors to cumulative incidence of age-related cataract and to progression of lens opacities over a 5-year interval.METHODS: A follow-up examination of the Beaver Dam Eye Study cohort was performed 5 years after the baseline evaluation. Ages at the census prior to baseline ranged from 43 to 84 years of age. Protocols for examination, lens photography, and grading were the same for both examinations.RESULTS: Age at baseline was the most significant characteristic associated with incidence of nuclear, cortical, and posterior subcapsular cataract in those without diabetes (P < .001) for all cataracts. The positive association of age with cataract was found for nuclear and cortical cataract in the worse eye (P ≤ .04) but not posterior subcapsular cataract in those with diabetes. Progression of nuclear sclerosis was common, occurring in about 70% of subjects when considering either eye. Incident cortical and posterior subcapsular cataracts (P ≤ .001 for worse eye for each lesion) and progression of cortical and posterior subcapsular opacities were more common in those with diabetes (P ≤ .001 for either eye for each lesion). Increased glycated hemoglobin level was associated with increased risk of nuclear and cortical cataracts in those with diabetes. Relationships of risk factors to posterior subcapsular cataracts, especially among those with diabetes, were often in the expected direction but lacked significance possibly due to small samples.CONCLUSIONS: Diabetes mellitus is associated with incidence over 5 years of cortical and posterior subcapsular cataract and with progression of more minor cortical and posterior subcapsular lens opacities. These changes may be related to level of glycemia. Cardiovascular disease and its risk factors have little effect on incidence of any age-related cataract.     

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.     

Myopic refractive shift caused by incident cataract: The Blue Mountains Eye Study

PURPOSE To assess the myopic shift in refraction caused by incident cataract in the Blue Mountains Eye Study (BMES) population. METHODS Five-year prospective follow-up of the BMES, initially performed in 1992. After 5 years, 2335 survivors (75.1%) of 3654 baseline BMES participants were re-examined. Refractive change was assessed by age, sex, incident cataract type and baseline refraction. Slit-lamp and retroillumination lens photographs were graded for presence of incident cataract and signs of previous cataract surgery. Objective and subjective refractions were performed. RESULTS In a multivariate model, age (p &lt; 0.0001), incident nuclear cataract (p &lt; 0.0003), hyperopia (p &lt; 0.0009), incident posterior subcapsular cataract (p &lt; 0.0027) and incident cortical cataract (p &lt; 0.025) were factors associated with a relatively modest myopic refractive shift (0.34 diopters). Baseline myopia and gender were not associated with refractive change over the follow-up period. A myopic shift in refraction occurred most frequently in older (=70 years) than younger (&lt;70 years) participants. CONCLUSIONS Older age, baseline hyperopia and all types of incident cataract were principal factors found associated with myopic refractive shift over 5 years in an older population.     

Drug use and five-year incidence of age-related cataracts: The Beaver Dam Eye Study

OBJECTIVE: To evaluate incident cataract after a 5-year interval with respect to medication use. DESIGN: Population-based incidence study. MAIN OUTCOME: Incident cataract judged from standard photographs. SETTING: Study subjects were adults 43 to 86 years of age in 1988 to 1990 and again in 1993 to 1995. All participants were examined and interviewed, and photographs were taken. All procedures and grading were done by protocols at both examinations. All medications in current use, prescribed as well as over-the-counter, were brought to the examination site, and the names were recorded at that time. RESULTS: There were 678 drug preparations (active ingredients) being used at the baseline examination. Significantly lower incidences of nuclear cataracts 5 years later occurred in those who took thiazide diuretics (odds ratio [OR] = 0.79, 95% confidence interval [CI] 0.63, 1.00) and aspirin (OR = 0.76, 95% CI 0.61, 0.95) at the baseline examination. There were significantly more incident cortical cataracts in those taking oral steroids (OR = 2.59, 95% CI 1.45, 4.62), amitriptyline (OR = 2.03, 95% CI 1.09, 3.79), oral hypoglycemic agents (OR 2.06, 95% CI 1.23, 3.44), and insulin (OR = 3.38, 95% CI 1.61, 7.08). There were significantly more incident posterior subcapsular cataracts in those taking potassium-sparing diuretics (OR = 2.13, 95% CI 1.42, 3.18) and oral hypoglycemic agents (OR = 2.89, 95% CI 1.57, 5.33). Considering past use with never and current use did not alter the patterns of associations. We were not able to separate the effects of antihypertensive or diuretic agents from that of hypertension. However, hypoglycemic agents were no longer associated with any cataract type after stratifying by diabetes status. CONCLUSIONS: Although many different medications were being used at the baseline examination in the Beaver Dam Eye Study cohort, few were associated with incident cataract. However, with the high frequency of use of medications and the possibility that effects of current exposure may occur in the future, it is reasonable to follow this and other older cohorts for the development 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.     

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

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

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.     

Contrast sensitivity and glare sensitivity changes with three types of cataract morphology: are these techniques necessary in a clinical evaluation of cataract?

LogMAR visual acuity, contrast sensitivity and glare sensitivity measurements were made on 39 eyes of 18 cataractous subjects and compared against normative data. Only cataracts of one of the main three morphological cataract types were used--cortical, nuclear and posterior subcapsular. Results indicate that contrast sensitivity decline with cataract is an intermediate and high spatial frequency loss. For nuclear and cortical cataracts with a LogMAR visual acuity of less than 0.5 (Snellen equivalent better than 6/18), there was no loss of contrast sensitivity at the lowest spatial frequency (1 c/deg). For posterior subcapsular cataracts, low spatial frequency contrast sensitivity loss did occur but was unrelated to visual acuity. Glare sensitivity increased for all cataract types. This was related to visual acuity for both cortical and nuclear cataracts but was not for the posterior subcapsular type. It was concluded that contrast and glare sensitivity measurements are a useful part of the assessment of visual function in patients with posterior subcapsular cataract.     

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

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

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

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

Refractive errors in a black adult population: the Barbados Eye Study.

PURPOSE: To describe the prevalence of refractive errors in a black adult population. METHODS: The Barbados Eye Study, a population-based study, included 4709 Barbados-born citizens, or 84% of a random sample, 40 to 84 years of age. Myopia and hyperopia were defined as a spherical equivalent <-0.5 diopters and >+0.5 diopters, respectively, based on automated refraction. Analyses included 4036 black participants without history of cataract surgery. Associations with myopia and hyperopia were evaluated in logistic regression analyses. RESULTS: The prevalence of myopia was 21.9% and was higher in men (25.0%) than in women (19.5%). The prevalence of hyperopia was 46.9% and was higher in women (51.8%) than in men (40.5%). The prevalence of myopia decreased from 17% in persons 40 to 49 years of age to 11% in those 50 to 59 years of age, but increased after 60 years of age. The prevalence of hyperopia increased from 29% at 40 to 49 years of age to 65% at 50 to 59 years of age, and tended to decline thereafter. A higher prevalence of myopia was positively associated (P < 0.05) with lifetime occupations requiring nearwork, nuclear opacities, posterior subcapsular opacities, glaucoma, and ocular hypertension. Factors associated with hyperopia were the same as for myopia, except for occupation, and in the opposite direction. CONCLUSIONS: High prevalences of myopia and hyperopia were found in this large black adult population. The prevalence of myopia (hyperopia) increased (decreased) after 60 years of age, which is inconsistent with data from other studies. The high prevalence of age-related cataract, glaucoma, and other eye conditions in the Barbados Eye Study population may contribute to the findings.     

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.