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R D Sperduto

Publications and source records attributed to R D Sperduto.

At least 37 records · Page 2Linked to original sources
PubMed1994

A dose-response effect between a sunlight index and age-related cataracts. Italian-American Cataract Study Group.

To explore the existence of a dose-response relationship between sunlight exposure and risk of age-related cataracts, we analyzed data collected from 1008 patients with cataracts and 469 control subjects enrolled in the Italian-American Case-Control Study of Age-Related Cataracts. Fourteen variables related to sunlight exposure history were included in the questionnaire administered to the study participants. A sunlight index was constructed and its relationship to the presence of cataracts was modeled by logistic regression. After adjustments for potential confounding variables and for age and sex, a significant dose-response effect (P = 0.01) was detected between the sunlight exposure index and the presence of pure cortical cataracts. With the exception of corticonuclear cataracts, all the other mixed types of opacity also showed a dose-response association with the sunlight index. These data support the hypothesis that sunlight exposure is a risk factor in the development of cortical cataracts, and demonstrate the existence of a dose-response relationship in this association.

Aged↗
PubMed1994

Influence of type and severity of pure forms of age-related cataract on visual acuity and contrast sensitivity. Italian American Cataract Study Group.

PURPOSE: To compare the relationship between logMAR visual acuity (VA) and cataract severity and between contrast sensitivity (CS) and cataract severity in pure types of age-related lens opacities. METHODS: Analysis included patients followed in the ongoing Italian-American Study of the Natural History of Age-Related Cataract. Lens opacities were classified and graded according to the Lens Opacities Classification System II (LOCS II). Visual acuity was measured with the Early Treatment Diabetic Retinopathy Study Chart. Contrast sensitivity was measured with the Pelli-Robson chart. RESULTS: Data from 1,076 eyes were used for the analysis (366 clear lenses; 550, 124, and 36 eyes with cortical, nuclear and posterior subcapsular cataract, respectively). In age-adjusted analyses, increasing severity of all three cataract types was associated with progressively higher logMAR VA, which translates into poorer acuity, and lower CS scores. For both VA and CS, the effect of increasing severity was greatest for nuclear and least for cortical opacities. After adjusting for age and VA, CS scores were no longer associated with cataract type and severity, with the exception of advanced cortical opacities. CONCLUSIONS: Increased cataract severity, as determined by LOCS II grading, is strongly associated with both VA and CS scores. Contrast sensitivity scores obtained from testing at low spatial frequency do not seem to offer additional information over standard VA testing in early cortical and posterior subcapsular opacities nor in nuclear cataracts.

Aged↗
PubMed1993

The Linxian cataract studies. Two nutrition intervention trials.

OBJECTIVE: To determine whether the vitamin/mineral supplements used in two cancer intervention trials affected the risk of developing age-related cataracts. DESIGN: Two randomized, double-masked trials with a duration of 5 to 6 years and end-of-trial eye examinations. SETTING: Rural communes in Linxian, China. PARTICIPANTS: In trial 1, 2141 participants aged 45 to 74 years, and, in trial 2, 3249 participants aged 45 to 74 years. INTERVENTIONS: Multivitamin/mineral supplement or matching placebo in trial 1; factorial design to test the effect of four different vitamin/mineral combinations in trial 2 (retinol/zinc, riboflavin/niacin, ascorbic acid/molybdenum, and selenium/alpha-tocopherol/beta carotene). MAIN OUTCOME MEASURES: Prevalence of nuclear, cortical, and posterior subcapsular cataracts in treatment groups at end of trials. RESULTS: In the first trial, there was a statistically significant 36% reduction in the prevalence of nuclear cataract for persons aged 65 to 74 years who received the supplements. In the second trial, the prevalence of nuclear cataract was significantly lower in persons receiving riboflavin/niacin compared with persons not receiving these vitamins. Again, persons in the oldest group, 65 to 74 years, benefited the most (44% reduction in prevalence). No treatment effect was noted for cortical cataract in either trial. Although the number of posterior subcapsular cataracts was very small, there was a statistically significant deleterious effect of treatment with riboflavin/niacin. CONCLUSIONS: Findings from the two trials suggest that vitamin/mineral supplements may decrease the risk of nuclear cataract. Additional research is needed in less nutritionally deprived populations before these findings can be translated into general nutritional recommendations.

Aged↗
PubMed1993

Arteriovenous crossing patterns in branch retinal vein occlusion. The Eye Disease Case-Control Study Group.

PURPOSE: The study was designed to evaluate the relative anatomic position of the crossing vessels at the site of occlusion in eyes with branch retinal vein occlusion (BRVO). METHODS: Fundus photographs of 106 eyes (104 patients) with recent BRVO from the Eye Disease Case-Control Study were used to examine the relative position of artery and vein at occluded crossings. Three separate comparison groups were formed by identifying corresponding arteriovenous crossings for each occluded crossing in: (1) the ipsilateral but opposite vessel arcade within eyes affected by BRVO; (2) the same quadrant in unaffected eyes of BRVO patients; and (3) the same quadrant in eyes of patients without BRVO, matched by age, sex, and race with the BRVO patients. RESULTS: The site of obstruction of the branch vein was an arteriovenous crossing in all affected eyes. In 99% of eyes with BRVO, the artery was located anterior to the vein at the obstructed site. In the three comparison groups, the artery was anterior to the vein in 62%, 61%, and 54% of the crossings, respectively, yielding statistically significant differences for each group of control crossings compared with BRVO crossings (P < 0.001). CONCLUSION: Finding the vein to be consistently between the more rigid artery and the retina at almost all arteriovenous crossings affected by BRVO suggests a possible role for mechanical obstruction in the pathogenesis of BRVO.

Adult↗
PubMed1991

Low-dose aspirin and risks of cataract in a randomized trial of US physicians.

Observational studies have raised the question of a possible benefit of aspirin on the development of cataract. The Physicians' Health Study, a randomized double-masked placebo-controlled trial among 22,071 male physicians, aged 40 to 84 years, provided the opportunity to collect information about whether low-dose aspirin therapy (325 mg on alternate days) affects the development or extraction of cataract. There were 173 age-related cataracts among those physicians assigned to aspirin therapy and 180 among those given placebo (relative risk, 0.95; 95% confidence interval, 0.74 to 1.22). Cataract extractions were less frequent in the aspirin than in the placebo group, but this difference was not statistically significant (relative risk, 0.80; 95% confidence interval, 0.56 to 1.15). Among younger men (aged 40 to 59 years), the relative risks were 0.62 (95% confidence interval, 0.40 to 0.94) for cataract development and 0.67 (95% confidence interval, 0.38 to 1.31) for cataract extraction. These randomized trial data tend to exclude any large benefit of aspirin. While the overall findings concerning cataract development seem to be null, the data on extraction of age-related cataract, while not statistically significant, cannot exclude a possible small to moderate benefit of alternate-day aspirin therapy on the extraction of age-related cataract.

Adult↗
PubMed1991

The effect of cataract severity and morphology on the reliability of the Lens Opacities Classification System II (LOCS II).

Data collected from 3646 eyes in the Italian-American Natural History Study of Age-Related Cataract were used to investigate whether the reliability of the Lens Opacities Classification System II (LOCS II) by the severity of the opacity that is being graded or is influenced by the presence and severity of coexisting opacities. Reliability was assessed by comparing the slit-lamp gradings of two clinical examiners (346 eyes) and the gradings performed at the slit lamp with gradings of photographs (3646 eyes). The severity of cortical and nuclear opacities did not affect the reproducibility of slit-lamp gradings, but clinical grading of posterior subcapsular opacities became more reliable as the severity of the posterior subcapsular opacities increased. More advanced coexisting opacities decreased the agreement in the slit-lamp diagnosis of nuclear, but not cortical or posterior subcapsular, opacities. Comparisons of clinical and photographic gradings showed very good to excellent agreement for nuclear and cortical opacities, regardless of the severity of the specific opacity or the severity of the coexisting opacities. Agreement in diagnosing posterior subcapsular opacities was decreased in eyes with milder posterior subcapsular opacities and in eyes with more severe coexisting nuclear and/or cortical opacities. The effect of the severity of the opacity being graded and the severity of coexisting opacities on the reliability of the LOCS II must be considered in studies that use the system to classify and grade cataracts.

Aged↗
PubMed1990

Distribution of lens opacities in the Italian-American Case-Control Study of Age-Related Cataract. The Italian-American Study Group.

The Lens Opacities Classification System I (LOCS I) was used to classify lens opacities in the clinic-based Italian-American Case-Control Study of Age-Related Cataract. Data on the distribution of cataract types among the 1008 patients (age range, 45-79 years) are presented. A single type of cataract was found in 65% of all cases in whom both lenses could be graded. Among all patients and among patients with only one type of cataract, cortical opacities occurred most frequently and posterior subcapsular opacities least frequently. In patients with bilateral cataracts there was a high degree of concordance of cataract type and severity. The high degree of concordance of cataract type between eyes and the decreasing prevalence of unilateral cataract with increasing age suggest that patients with unilateral cataract are at high risk of developing the same opacity in the fellow eye. Cortical cataracts were found more frequently in women, and in patients with unilateral cataract, the left eye was more frequently affected. Clinic-based data on the distribution of cataract may be of assistance in planning future clinical studies of cataract.

Aged↗
PubMed1990

Evaluation of an iris color classification system. The Eye Disorders Case-Control Study Group.

A system for classification of iris color based on standard photographs, developed for use in a multicenter study, is described. Categories of iris color are distinguished based on predominant color (blue, gray, green, light brown, or brown) and the amount of brown or yellow pigment present in the iris. Two trained readers independently graded 339 iris photographs; discrepancies in grades were adjudicated. Measures of interobserver reliability were 0.76 by kappa for exact agreement and 0.97 for weighted kappa. The distribution of iris color grades demonstrates that the system achieved an appropriate level of detail within the authors' study population, which included patients with various racial backgrounds from five urban clinical centers. This simple, reliable classification system for iris color is offered for use in clinical research.

Analysis of Variance↗
PubMed1989

Age-related cataract in the Tibet Eye Study.

The Tibet Eye Study was designed to estimate the prevalence of age-related cataract in Duilong-Deqing County, west of Lhasa, China (altitude, 4000 m). Previous reports have suggested an unusually high prevalence of age-related cataract in Tibet. A two-stage probability sample of persons aged 20 years or older from the 35 townships of the county targeted 2884 persons for inclusion in the study; 2665 (92.4%) were examined. Age-related cataract was diagnosed when (1) visual acuity was worse than 6/12 (20/40) because of nuclear or cortical (including posterior subcapsular) opacities, or (2) aphakia associated with a history of age-related cataract was present in either eye. The prevalence of age-related cataract among persons aged 20 to 39 years was 0.2%; among persons 40 years old or older, the prevalence was 11.8%. Cortical cataracts were by far the most common type of cataract diagnosed. Age- and sex-adjusted prevalence in Tibet was 60% higher than the prevalence in a similar, previously conducted study of 6951 person in Shunyi County, northeast of Beijing (altitude, 50 m). A second, independent slit-lamp classification of lens status was conducted in the Tibet Eye Study using standard photographs previously described. Age-specific cataract prevalence was similar with the two examination techniques. Results from the Tibet Eye Study support previous suggestions of a high prevalence of age-related cataract in Tibet.

Adult↗
PubMed1989

India-US case-control study of age-related cataracts. India-US Case-Control Study Group.

In a hospital-based case-control study of 1441 patients with age-related cataracts and 549 controls, we studied associations between types of cataract--nuclear, cortical, posterior subcapsular, and mixed--and a number of physiologic, behavioral, environmental, and biochemical variables. Using polychotomous logistic regression analysis, we found an increased risk of cataract with lower educational achievement (all types of cataract), decreased cloud cover at place of residence (all types), use of aspirin less than once a month (posterior subcapsular and mixed), diets low in selected nutrients (posterior subcapsular, nuclear, and mixed), higher blood pressure (nuclear and mixed), lower body mass index (nuclear and mixed), use of cheaper cooking fuels (cortical, nuclear, and mixed), and lower levels of an antioxidant index based on red blood cell levels of glutathione peroxidase and glucose-6-phosphate dehydrogenase and plasma levels of ascorbic acid and vitamin E (posterior subcapsular and mixed). All risks cited were significantly different from those for the other cataract types, a finding that emphasizes the need to investigate the epidemiology of specific types of cataract.

Adult↗
PubMed1989

Lens changes and the incidence of cardiovascular events among persons with diabetes.

Previous analysis of data from the Framingham Heart Study and the Framingham Eye Study showed that the "all-cause" death rate for diabetic persons with lens opacities was more than twice that of diabetic persons without lens opacities. Additional follow-up information was used to investigate whether these lens changes were associated with cardiovascular morbidity and mortality in particular. At the eye examination (1973 to 1975) there were 133 diabetic persons with no cardiovascular disease, of whom 41% had lens changes. Of these 133 persons, 57 had at least one cardiovascular event by the time of the most recent follow-up examination (1981 to 1983). Regression analyses suggested an increased risk of cardiovascular events among diabetic persons with lens changes (incidence rate ratio = 1.8; p = 0.07). Specifically there were associations of lens changes with the development of congestive heart failure (incidence rate ratio = 3.6; p = 0.01) and coronary heart disease (incidence rate ratio = 2.4; p = 0.08). Thus lens changes, in addition to being early prognostic signs of mortality, appear to be predictors of cardiovascular disease in adult-onset diabetes.

Age Factors↗
PubMed1989

An independent evaluation of the Lens Opacities Classification System II (LOCS II). The Italian-American Cataract Study Group.

The Lens Opacities Classification System II (LOCS II) has been offered for use in clinical studies of cataract. The system uses slit lamp and retroillumination photographic standards to grade lens opacities into classes of increasing severity. The authors evaluated the reproducibility and validity of LOCS II before its possible use in a natural history study of age-related cataract. The authors found excellent inter- and intraobserver reproducibility when the LOCS II standard photographs were used for clinical or photographic gradings of cataract. There was a tendency to underestimate posterior subcapsular cataracts on photographic gradings compared with slit-lamp gradings. The accuracy of the photographic gradings of posterior subcapsular opacities tended to decrease as the severity of coexisting opacities increased.

Aged↗
PubMed1989

Measurement error in assessing the size of posterior subcapsular cataracts from retroillumination photographs.

Twenty-six eyes with posterior subcapsular opacities of various sizes were photographed with the Neitz-Kawara Retroillumination camera. The outline of the opacity in a single photograph of each opacity was traced onto a transparent plastic overlay twice by two independent outliners. Two methods were used to estimate the area within the outlines of the opacities. In the first, a transparent overlay with a standard grid was used to count the number of boxes within the outlines. The second method used computer planimetry to estimate the area within the tracings. We estimated the measurement error associated with a single outlining of an opacity and the contribution of the measurement error to overall sample size requirements in studies comparing the mean areas of posterior subcapsular opacities. Variability in the measurement techniques contributed fewer than 20 additional subjects to overall sample size estimates, a small contribution to total sample size requirements in most studies. An outliner's inherent variability in outlining an opacity was a much larger contributor to the measurement error than was variability in assessing the area of the outline of the opacity. While within outliner variability was similar for the two persons outlining the opacities, there were systematic differences in the way the two traced the outlines. Variability from the use of separate photographs of the same opacity taken by different photographers was minimal.

Cataract↗
PubMed1988

Diabetic retinopathy and cardiovascular disease in type II diabetics. The Framingham Heart Study and the Framingham Eye Study.

Data from the Framingham Heart Study and the Framingham Eye Study were used to examine the association between diabetic retinopathy and the occurrence of cardiovascular events (coronary heart disease, intermittent claudication, congestive heart failure, and stroke). Among the 206 persons with Type II diabetes in the Framingham Eye Study, the odds ratios for diabetic retinopathy and cardiovascular disease were 14.3 (95% confidence interval (CI) = 2.7-101.9), 2.0 (95% CI = 0.5-8.1), and 0.3 (95% CI = 0.05-1.3) for ages 52-64, 65-74, and 75-85 years, respectively. The test for homogeneity indicated highly significant differences for the odds ratios across age groups. The associations were similar when sex, duration of diabetes, age at diagnosis of diabetes, and history of insulin treatment were accounted for by logistic regression. Our data suggest an association in younger diabetics between diabetic retinopathy, a small vessel complication of diabetes, and a group of cardiovascular events commonly thought to result from large vessel disease. The finding may merely indicate that diabetics with large vessel disease are also more likely to have small vessel disease. However, it is also consistent with the hypothesis, suggested by histologic data, that a more generalized microangiopathy affecting not only the eye but also organs such as the heart may play a role in the pathogenesis of cardiovascular disease in diabetics.

Age Factors↗
PubMed1987

Factors affecting outcome and predictability of radial keratotomy in the PERK Study.

The Prospective Evaluation of Radial Keratotomy (PERK) study used a standardized surgical technique that included a central clear zone with a diameter of 4.0, 3.5, or 3.0 mm. Multiple regression analysis of the outcome in one eye from each of 411 patients disclosed that the diameter of the central clear zone, patient age, and depth of the incision scar were the major factors affecting the change in refraction one year after surgery. Preoperative factors examined that did not have a significant influence on the outcome were sex, average central keratometric power, corneal thickness, corneal diameter, intraocular pressure, and ocular rigidity. The predictability of radial keratotomy, ie, the precision with which the outcome can be estimated, was measured by the 90% confidence interval for the change in refraction based on the regression equation. The width of this interval within each clear zone group was as follows: 4.0 mm, 2.49 diopters; 3.5 mm, 3.38 D; 3.0 mm, 4.12 D. For all 411 eyes, the 90% confidence interval was approximately 3.50 D wide. Thus, the surgeon could be 90% certain that an individual patient's refraction would be within 1.75 D of the predicted value one year after surgery.

Age Factors↗
PubMed1987

Relationship between refractive error and visual acuity in the Prospective Evaluation of Radial Keratotomy (PERK) Study.

As part of the Prospective Evaluation of Radial Keratotomy (PERK) study, we examined the relationship between post-operative refractive error and visual acuity without correction. We included 394 eyes (one eye per patient) with refractive errors ranging from -3.00 to +3.00 diopters one year after radial keratotomy. Within each 1-D range of the spherical equivalent of the refractive error, the visual acuity spanned five to ten Snellen lines. For visual acuities of 20/16 to 20/50, the refractive error spanned 3 to 5 D. Additionally, operated eyes had a better average uncorrected visual acuity than unoperated eyes with a similar refractive error. Within the narrow range of refraction between -2.00 and -2.50 D, the mean uncorrected visual acuity was 20/125 for 56 unoperated eyes and 20/63 for 29 operated eyes, a difference of three Snellen lines.

Adult↗
PubMed1987

Indo-US case-control study of senile cataract--design and development.

Study design and development are presented for an investigation of risk factors for senile cataract in a collaborative Indo-US case-control study in New Delhi, India. This study emphasizes the relationship of nutritional status, as ascertained by biochemical assessment on plasma and red blood cells and by dietary history, to specific cataract types (nuclear, cortical, posterior subcapsular).

Adult↗