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J M Seddon

Publications and source records attributed to J M Seddon.

At least 19 recordsLinked to original sources
PubMed1992

Occupation and risk of uveal melanoma. An exploratory study.

BACKGROUND: Little is known about the cause of uveal melanoma, the most common primary intraocular malignant lesion in adults. This population-based case-control study evaluated occupational exposures. METHODS: One hundred ninety-seven newly diagnosed cases of uveal melanoma participated. Approximately two control subjects matched for age, sex, and telephone exchange area were selected for each case by random-digit dialing. Data were collected by a structured telephone interview. Two systems of occupational coding were used: an occupation-exposure linkage system and the Bureau of Census data. Conditional logistic regression for matched studies was used to examine various occupational exposures while controlling for previously reported potential confounders and for family income. The occupation-exposure matrix was used to define clusters of cases exposed to a particular chemical group from various occupations. RESULTS: Odds ratios were elevated for agriculture and farming work for both industry and occupation; this was consistent across both classification systems. Elevated odds ratios also were found for occupations involving machine operations, fabrication, assembling, equipment cleaning, and exposure to metal industries. Exposure to alkylating agents and phenols was associated with a lower risk compared with all other exposures. Several self-reported exposures also were studied. Exposures associated with elevated odds ratios were inks, insecticides, gases, radioactive substances, polybromated biphenyls, and chemical solvents. CONCLUSIONS: This exploratory study suggests various occupational associations for uveal melanoma and areas for future research.

Adolescent↗
PubMed1992

A prospective study of cigarette smoking and risk of cataract in men.

OBJECTIVE: To examine the association between cigarette smoking and the incidence of cataract. DESIGN, SETTING, AND PARTICIPANTS: The design was a prospective cohort study using data from the Physicians' Health Study, a randomized trial of aspirin and beta carotene among 22,071 US male physicians aged 40 to 84 years that began in 1982. This analysis includes the 17,824 physicians who did not report cataract at baseline and did provide complete risk factor information. Based on information reported at baseline, 10% were current smokers, 39% were past smokers, and 51% were never smokers. MAIN OUTCOME MEASURE: An incident cataract was defined as a self-report confirmed by medical record review to have been first diagnosed after randomization, age-related in origin, and responsible for a decrease in best corrected visual acuity to 20/30 or worse. MAIN RESULTS: During 60 months of follow-up, 557 incident cataracts among 371 participants were confirmed. Compared with never smokers, current smokers of 20 or more cigarettes per day had a statistically significant increase in the risk of cataract (relative risk [RR], 2.16; 95% confidence interval [Cl], 1.46 to 3.20; P less than .001). Similar results were obtained after simultaneously controlling for other potential cataract risk factors in a logistic regression model (RR, 2.05; 95% Cl, 1.38 to 3.05; P less than .001). Among the 557 eyes with cataract, nuclear sclerotic changes were present in 442 while posterior subcapsular changes were present in 204. After controlling for other potential cataract risk factors, current smokers of 20 or more cigarettes per day had statistically significant increases in nuclear sclerosis (RR, 2.24; 95% Cl, 1.47 to 3.41; P less than .001) and posterior subcapsular (RR, 3.17; 95% Cl, 1.81 to 5.53; P less than .001) cataract. Past smokers had an elevated risk of posterior subcapsular (RR, 1.44; 95% Cl, 0.97 to 2.13; P = .07) but not nuclear sclerosis cataract. For current smokers of fewer than 20 cigarettes per day, no increased risks were observed of total, nuclear sclerosis, or posterior subcapsular cataract. CONCLUSIONS: These data provide support for the hypothesis that cigarette smoking increases the risk of developing both nuclear sclerosis and posterior subcapsular cataract.

Adult↗
PubMed1992

A prospective study of cigarette smoking and risk of cataract surgery in women.

OBJECTIVE: To examine prospectively the association between cigarette smoking and the risk of cataract extraction in women. DESIGN: Prospective cohort study beginning in 1980 with 8 years of follow-up. SETTING: United States, multistate. PARTICIPANTS: Registered nurses 45 to 67 years of age and free of diagnosed cancer. There were 50,828 women included in 1980 and others were added as they became 45 years of age. MAIN OUTCOME MEASURE: Incidence of senile cataract extraction. RESULTS: We documented 493 incident senile cataracts diagnosed and extracted during 470,302 person-years of follow-up. The age-adjusted relative risk (RR) among women who smoked at least 65 pack-years was 1.63 (95% confidence interval [Cl], 1.18 to 2.26; P for trend, .02). A similar increase in RR was noted when smoking was assessed in terms of number of cigarettes currently smoked or number of cigarettes smoked by past smokers. Results were also similar after adjusting for other potential risk factors for cataract. Smoking was also strongly associated with posterior subcapsular cataract specifically (RR, 2.59; 95% Cl, 1.49 to 4.50 for greater than or equal to 65-pack-year smokers relative to nonsmokers. CONCLUSION: Smoking appears to increase the risk of cataract extraction.

Aged↗
PubMed1992

Nutrient intake and cataract extraction in women: a prospective study.

OBJECTIVE: To examine prospectively the association between dietary intake of vitamins C and E, carotene, and riboflavin and cataract extraction in women. DESIGN: Prospective cohort study beginning in 1980 with eight years of follow up. SETTING: 11 states of the United States. PARTICIPANTS: Female registered nurses who were 45 to 67 years of age. 50,828 women were included in 1980 and others were added as they became 45 years of age. MAIN OUTCOME MEASURE: Incidence of extraction of senile cataracts. RESULTS: 493 cataracts were extracted during 470,302 person years of follow up. Intake of carotene and vitamin A was inversely associated with cataract: in multivariate analyses, women in the highest fifth of total vitamin A intake (excluding supplements) had a 39% lower risk of cataract relative to women in the lowest fifth (relative risk 0.61; 95% confidence interval 0.45 to 0.81). Neither riboflavin nor dietary vitamins E or C were associated with cataract in a multivariate analysis. Among specific food items spinach (rather than carrots, the greatest source of beta carotene) was most consistently associated with a lower relative risk. The risk of cataract was 45% lower among women who used vitamin C supplements for 10 or more years(relative risk 0.55 (0.32 to 0.96)), but no association was noted for multivitamin intake. CONCLUSION: Dietary carotenoids, although not necessarily beta carotene, and long term vitamin C supplementation may decrease the risk of cataracts severe enough to require extraction.

Aged↗
PubMed1992

Lipid polymorphism: a correction. The structure of the cubic phase of extinction symbol Fd-- consists of two types of disjointed reverse micelles embedded in a three-dimensional hydrocarbon matrix.

The X-ray scattering study of a cubic phase of extinction symbol Fd--, recently performed on a lipid extract (PFL) from Pseudomonas fluorescens [Mariani et al. (1990) Biochemistry 29, 6799-6810] has been extended to several other systems, all consisting of mixtures of water-miscible (MO, PC, PE, oleate) and of water-immiscible (FA, DG) lipids, plus water. In all of these systems the cubic phase was observed in the presence of excess water. Some inconsistencies observed between PFL and the other systems, the fact that in PFL one of the reflections of the cubic phase happened to coincide with the strongest reflection of the hexagonal phase, and the finding, in one of the original cubic samples of PFL kept in the cold for more than 3 years, that the intensity of one of the reflections had decreased dramatically all indicated that a nonnegligible amount of a hexagonal impurity was in fact present in the samples of PFL originally thought to contain a pure cubic phase. The intensities were corrected for that impurity and analyzed again using a pattern recognition approach based upon the axiom that the histogram of the electron density maps is invariant with respect to physical structure, when different phases are compared whose chemical composition is the same. The hexagonal phase provided the reference phase for the comparison. The moments mean value of (delta rho)n were used to compare the histograms.(ABSTRACT TRUNCATED AT 250 WORDS)

Crystallography↗
PubMed1992

Cataract extraction after proton beam irradiation for malignant melanoma of the eye.

We evaluated visual outcome and risk of metastases in patients who underwent cataract extraction after protonbeam irradiation of a uveal melanoma. A total of 84 patients underwent cataract extraction between 2 months and 11 years after irradiation. One year after cataract extraction, approximately half of the patients had visual acuity of 20/100 or better, and approximately one third had an acuity of 20/40 or better. Larger tumor size was highly correlated with poor visual outcome 1 year after extraction. Six patients underwent enucleation after cataract removal, five due to blind, painful eyes and one due to continued growth of a previously undiagnosed ring melanoma. The rate of metastases was not higher among patients who underwent cataract extraction (adjusted rate ratio, 0.83). Results suggest that cataract extraction offers improvement of vision in selected eyes previously irradiated for a uveal melanoma, without adding to the risk of metastases among patients undergoing the procedure.

Adult↗
PubMed1992

Histopathology of proton beam-irradiated vs enucleated uveal melanomas.

The histopathology of eyes with uveal melanoma was compared in a masked fashion in 47 eyes whose primary treatment was enucleation and a matched series of 47 eyes enucleated after proton beam irradiation. Irradiated tumors were more likely to show signs of necrosis (P less than .001) and fibrosis (P = .005) and to have balloon cells present (P = .002). In the irradiated group, mitotic figures were fewer in 40 high-power fields (P = .020), and the prevalence of tumor blood vessel damage (P less than .001) was higher. Changes in the retina were more common in the irradiated series, but damage was usually overlying or in close proximity to the tumor. Based on characteristic changes, the pathologist distinguished irradiated from nonirradiated eyes in 85% of the cases. These findings suggest that irradiation damages tumor cells and blood vessels, and alters the tumor's capacity for cellular reproduction.

Adult↗
PubMed1992

Radiation maculopathy after proton beam irradiation for choroidal melanoma.

PURPOSE: Radiation maculopathy is a microangiopathy of the retina, which is often observed after irradiation of the eye. To quantitatively determine the frequency of anatomic and functional features of this condition, the authors reviewed a large series of patients with choroidal melanomas who were treated by proton beam irradiation. METHODS: Color photographs and/or fluorescein angiograms of 218 patients with paramacular choroidal melanomas were graded by two independent masked readers to determine the frequency of the various lesions of radiation maculopathy. RESULTS: Overall, 194 (89%) of the 218 patients in this study developed some degree of radiation maculopathy. The earliest and most common finding was macular edema, which was observed in 87% of patients, overall, by the end of year 3. Microvascular changes (microaneurysms and/or telangiectasia), intraretinal hemorrhages, and capillary nonperfusion were noted in 76%, 70%, and 64% of eyes, respectively, by the end of postirradiation year 3. Visual acuity was retained at 20/200 or better in 90% of eyes 1 year after irradiation and in 67% of eyes 3 years after treatment. CONCLUSION: Radiation maculopathy is common after proton beam irradiation of paramacular choroidal melanomas. However, ambulatory vision is preserved in many eyes.

Adolescent↗
PubMed1992

Intraocular recurrence of uveal melanoma after proton beam irradiation.

The authors evaluated tumor recurrence as an end point in 1077 uveal melanoma patients treated by proton beam irradiation between 1975 and 1987, with a mean follow-up of 4.0 years. Twenty tumors (1.9%) exhibited definitive growth between 4 months and 66 months after irradiation (median, 19 months): 10 were marginal recurrences, 5 were ring melanomas, 3 were uncontrolled tumors, and 2 were extrascleral extensions. Ten of these eyes were enucleated without further intervention, 2 patients died of metastases soon after the growth was detected, and 8 patients had further conservative therapy. In 5 other patients, tumor growth was suspected but unconfirmed and the eye was enucleated elsewhere; the 5-year probability of local tumor control based on 25 recurrences was 97% +/- 1%. There was a nonsignificant increase in the rate of metastases among patients with documented tumor recurrence (adjusted relative risk, 1.5; 95% confidence interval, 0.66 to 3.4). Results suggest that recurrence of uveal melanomas treated by proton beam therapy is uncommon, but that treatment failure may increase risk of death from metastasis.

Adolescent↗
PubMed1992

Smoking and the risk of early metastases from uveal melanoma.

Smoking is suspected of altering host immunity and may therefore hasten the development of metastases among cancer patients. The authors followed 946 patients with melanomas of the choroid and/or ciliary body who had been treated with proton beam irradiation and who had provided a smoking history during their evaluation before treatment. After a mean follow-up of 33 months, 98 patients were diagnosed with metastatic disease. Metastasis-free survival rates 3 years after irradiation were similar in association with never, past, and current cigarette smoking (86%, 89%, and 90%, respectively; P = 0.90). Rates also were similar with increasing pack-years of exposure and when the product smoked was cigarettes versus pipes or cigars only. Estimates for smoking effects were unchanged after adjusting for established prognostic factors for metastases. Results suggest that smoking does not alter the risk of metastases during the first few years after irradiation of choroidal melanomas.

Adolescent↗
PubMed1992

Development of the 'Activities of Daily Vision Scale'. A measure of visual functional status.

To develop a method for the evaluation of visual function in subjects with cataracts, the authors identified 20 visual activities and categorized them into five subscales (distance vision, near vision, glare disability, night driving, and daytime driving) that comprised the Activities of Daily Vision Scale (ADVS). Each subscale in the ADVS was scored between 100 (no visual difficulty) and 0 (inability to perform the activity because of visual difficulty). In 334 subjects scheduled for cataract extraction (mean age 75 +/- 9 years, 67% women), ADVS scores (mean +/- standard deviation) for each subscale ranged from 44 +/- 31 for night driving to 72 +/- 24 for near vision activities. When administered by telephone, inter-rater reliability coefficients (r) were 0.82 to 0.97 (P < 0.001) for each of the subscales, and test-retest reliability was 0.87 for the scale overall. Cronbach's coefficient alpha was very high for both the in-person (alpha = 0.94) and telephone (alpha = 0.91) formats. Criterion validity, the correlation between visual loss and ADVS score, was -0.37 (P < 0.001) when the ADVS was administered in person and -0.39 (P < 0.001) when it was administered by telephone. Content validity as assessed with factor analysis showed that 88% of the variance of the principal components weighted on one factor. The authors conclude that substantial visual disability is not captured by routine visual testing and that the ADVS is a reliable and valid measure of patient's perception of visual functional impairment.

Activities of Daily Living↗
PubMed1992

Evaluation of skin microtopography as a measure of ultraviolet exposure.

A pilot study was conducted to investigate the use of skin microtopography as a semiquantitative noninvasive method for estimating cumulative sun exposure in epidemiologic studies of eye disease. The subjects received a kit through the mail containing materials needed to make a replica of the skin texture of a sun-exposed area of the hand. Each subject previously had undergone a skin biopsy around the same site to evaluate elastotic degeneration, and all were interviewed about past sun exposures. A gradable skin impression was obtained from 96 of 115 (83%) participants after two mailings. The impressions were graded according to the degree of skin texture alteration using standard photographs; interobserver reliability was 0.73 using a weighted kappa statistic. The impression score was correlated most strongly with age (r = 0.53). Independent predictors of higher impression scores (more skin texture changes) were older age, cigar or pipe smoking, less education, lighter iris color, lighter skin color, male gender, and tendency to sunburn. After adjustment for age and the other predictor variables, the biopsy score was not correlated with the impression grade (r = 0.18, P = 0.13). Behaviors indexing sun exposure were not correlated with microtopography. These results suggest that skin microtopography as done in this study reflects aging from intrinsic parameters more than from actinic damage.

Adolescent↗
PubMed1991

Retinal pigment epithelial tears associated with trauma.

Two previously healthy patients, a 66-year-old man with blunt trauma to the right eye, and a 28-year-old man with head trauma from a motorcycle accident, were observed to have parafoveal retinal pigment epithelial tears after injury. In both patients, fluorescein angiography demonstrated mottled window defects in the areas of the tears, and blocked fluorescence in the areas of the rolled-up pigment epithelium. Neither eye had evidence of pigment epithelial detachments. We hypothesize that this unusual phenomenon is caused by an acute tractional force oriented tangentially to the macular plane, the result of a rapid spherically expansile deformation of the globe during trauma.

Accidents, Traffic↗
PubMed1991

The incidence of ulcerative keratitis among aphakic contact lens wearers in New England.

We conducted a population-based incidence study in five New England states to quantify the risk of ulcerative keratitis associated with contact lens use among aphakic persons. All practicing ophthalmologists in the five-state area were surveyed to identify prospectively all new cases of ulcerative keratitis during a 4-month period. The number of aphakic persons using specific types of contact lenses was estimated through a telephone survey of 4178 households identified by random digit dialing. The annualized incidence of ulcerative keratitis among aphakic persons using contact lenses was estimated to be 52 cases per 10,000 aphakic contact lens wearers (95% confidence interval (CI), 31.1 to 86.9). The risk of ulcerative keratitis varied substantially by lens use, with extended wear having an estimated sevenfold greater risk relative to daily wear (95% CI, 1.6 to 30.2). Rates of ulcerative keratitis in aphakic persons using contact lenses were much greater than rates among cosmetic wearers of the same lens type: for daily-wear lenses, aphakic persons were estimated to have 6.3 times the risk of cosmetic wearers (95% CI, 1.9 to 21.0), and for extended-wear lenses, aphakic persons were estimated to have 8.7 times the risk of cosmetic wearers (95% CI, 3.5 to 21.9). These risks are useful in assessing the benefits and risks of contact lens wear as an alternative to other methods of aphakic correction.

Adolescent↗
PubMed1991

Falls in elderly patients with glaucoma.

We analyzed the determinants of serious falls among 489 ambulatory elders aged 65 years and older who received a comprehensive examination at a glaucoma consultation service. For the previous year, at least one fall requiring medical attention or restricted activity was reported by 9.6% (95% confidence interval [CI], 7.0% to 12.2%) of participants. Using logistic regression to adjust for potential confounding variables, the greatest single risk factor for falls was the use of nonmiotic topical eye medications (odds ratio [OR], 5.4; 95% Cl, 1.8 to 16.4). Additional risk factors for falls were female sex (OR, 2.3; 95% Cl, 1.1 to 4.7) and use of cardiac medications (OR, 2.5; 95% Cl, 1.1 to 5.6). Three other characteristics were also associated with the risk of falls: use of miotic eye medications (OR, 3.2; 95% Cl, 1.0 to 10.1); visual field impairment of 40% or greater (OR, 3.0; 95% Cl, 0.94 to 9.8); and use of sedatives (OR, 2.4; 95% Cl, 0.89 to 6.7). These findings suggest that ocular and systemic medications are the major predictors of falls even in this elderly population seeking ophthalmologic care for glaucoma. Medications appear to pose a greater risk for falls than even major visual impairment.

Accidental Falls↗
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

Survival of patients with metastases from uveal melanoma.

The authors evaluated a series of 145 consecutive patients with metastases from uveal melanoma, after proton beam irradiation, to assess the effect of early diagnosis and treatment for metastases on survival. Metastases were diagnosed between 7 weeks and 8.3 years (median, 2.4 years) after proton beam irradiation. Most patients (n = 94) were symptomatic before diagnosis; the remainder were first detected during screening examination. Liver involvement was documented in nearly all patients (n = 136). The majority of patients had died from metastases by the close of the study (n = 137). Significantly longer survival occurred among patients diagnosed during screening examination (P = 0.004) and among young patients (P = 0.03). The majority of patients received some form of treatment for metastases (69%). Median survival was 2.0 months for patients receiving no treatment compared with 5.2 months for those receiving treatment for metastases (P = .0001). However, the overall 1-year survival rate was poor (13%). Prophylactic adjuvant therapy could be explored as a means to increase disease-free survival in patients with uveal melanoma.

Adult↗