Biomedical subjects

R J Glynn

Publications and source records attributed to R J Glynn.

At least 19 recordsLinked to original sources

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

Accounting for the correlation between fellow eyes in regression analysis.

Regression techniques that appropriately use all available eyes have infrequently been applied in the ophthalmologic literature, despite advances both in the development of statistical models and in the availability of computer software to fit these models. We considered the general linear model and polychotomous logistic regression approaches of Rosner and the estimating equation approach of Liang and Zeger, applied to both linear and logistic regression. Methods were illustrated with the use of two real data sets: (1) impairment of visual acuity in patients with retinitis pigmentosa and (2) overall visual field impairment in elderly patients evaluated for glaucoma. We discuss the interpretation of coefficients from these models and the advantages of these approaches compared with alternative approaches, such as treating individuals rather than eyes as the unit of analysis, separate regression analyses of right and left eyes, or utilization of ordinary regression techniques without accounting for the correlation between fellow eyes. Specific advantages include enhanced statistical power, more interpretable regression coefficients, greater precision of estimation, and less sensitivity to missing data for some eyes. We concluded that these models should be used more frequently in ophthalmologic research, and we provide guidelines for choosing between alternative models.

Adolescent↗

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

Functional blindness and visual impairment in older adults from three communities.

PURPOSE: The purpose of this study is to examine the association of sociodemographic factors with functional blindness and visual impairment in an aged population. METHODS: Three population-based cohorts (East Boston, MA; New Haven, CT; and Iowa and Washington Counties, IA) of persons aged 71 years and older were screened for bilateral functional near and distant vision during an in-home interview in 1988. RESULTS: Screening was completed by 5335 participants. The prevalence of functional blindness increased with age, from 1% at age 71 to 74 years to 17% in those 90 years of age and older. Functional visual impairment increased from 7% at age 71 to 74 years to 39% in those 90 years of age and older. In multivariate analyses, residence in a nursing home, older age, glaucoma, insulin-requiring diabetes at baseline, East Boston site, history of cataract, and lower 1982 income were independent and significantly associated with both functional blindness and visual impairment. Age and nursing home residence were significantly (P < 0.05) more strongly associated with blindness (odds ratios 4.8 and 6.1, respectively) than they were with visual impairment. CONCLUSION: Functional blindness and visual impairment are quite prevalent among the oldest old and the institutionalized. The number of affected individuals will increase as the population ages and life expectancy increases. Although visual problems are associated with aging, nursing home residence, health problems, and socioeconomic conditions, they may be readily remediable and may lead to immediate improvements in quality of life.

Aged↗

PubMed1992

Use of medications by persons 65 and over: data from the established populations for epidemiologic studies of the elderly.

Data were analyzed from household interviews of four population-based cohorts comprising the Established Populations for Epidemiologic Studies of the Elderly to estimate the prevalence of prescription and nonprescription medication use among community-living elderly and to examine sociodemographic and health factors related to medication use. Prescription drugs were used by 60-68% of men and 68-78% of women. Nonprescription drugs were used by 52-68% of men and 64-76% of women. Use of prescription medications generally increased with age although use of nonprescription drugs was not associated with age. Men and women who smoked or used alcohol in the preceding year frequently took medications. Those who reported more depressive symptoms, impairments in physical functioning, hospitalizations, and had poorer self-perceived health status were most likely to take medications. However, 10-29% of respondents with fair or poor self-perceived health took no prescription medications, and 3-13% took neither prescription nor nonprescription medications. While further research appears warranted into potential overmedication of elders, particularly those with many depressive symptoms, these data suggest that studies of potential underuse among elders with poor health are equally important.

Activities of Daily Living↗

PubMed1992

Preservation of hearing and facial nerve function in resection of acoustic neuroma.

The surgical results in 78 recent cases of total removal of unilateral acoustic neuroma in which an attempt was made to preserve cochlear function have been added to the authors' previous series of 66 cases to evaluate the factors influencing the ability to preserve useful hearing. Useful hearing was defined by speech reception threshold no poorer than 70 dB and a discrimination score of at least 15%. Analysis using a logistic regression model showed that certain preoperative clinical parameters such as tumor size, speech discrimination score, and gender were significantly correlated with hearing outcome. Favorable outcome was significantly correlated with smaller tumor size, higher preoperative speech discrimination score, and male sex. From this data, an explicit formula was devised for predicting hearing outcome for an individual patient. In four cases with useful hearing preserved, there was improvement of greater than 15 percentage points in speech discrimination scores. While preoperative auditory brainstem responses were not predictive of hearing preservation, monitoring of intraoperative auditory evoked potentials was predictive of hearing outcome in selected cases. Specifically, when wave V was unchanged at the end of the operation, even if it may have been transiently lost during surgery, useful hearing was invariably preserved.

Audiometry, Evoked Response↗

PubMed1992

Alcohol consumption and mortality in an American male population: recovering the U-shaped curve--findings from the normative Aging Study.

Several prospective studies have suggested that moderate alcohol consumption may offer protection against total and coronary heart disease (CHD) mortality. These studies have been criticized for failing to control for changes in drinking and the influence of comorbidity on consumption decisions. In the present study, we examined whether rates of death from all causes and from CHD were related to overall consumption as well as variability in or problems with drinking. In 1973, a drinking questionnaire was completed by 1,823 male subjects participating in a longitudinal study who were prescreened for absence of serious or chronic disease. After 12 years of follow-up per subject (21,716 man years of follow-up in all), 159 men have died, 74 from CHD. Incidence rates of overall mortality were lowest for moderate drinkers in each of three age groups. CHD death rates for moderate drinkers were similar to those of non-drinkers except in the oldest men where rates were lower for moderate drinkers. Proportional hazards models testing several measures of consumption consistently showed moderate or regular drinkers to have lower risk of death than teetotalers. Regular drinkers had lower overall and CHD mortality than lifetime abstainers. For all-cause and CHD mortality, drinking heavily in the past, ever having tried to quit drinking and having had problems with alcohol were not related to increased risk. These results lend support to the hypothesis of the beneficial effect of moderate drinking, with respect to mortality.

Alcohol Drinking↗

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

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

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↗

PubMed1990

Host factors, UV radiation, and risk of uveal melanoma. A case-control study.

Uveal melanoma threatens life, as well as sight. To evaluate the effect of constitutional factors and UV radiation on the risk of uveal melanoma, 197 cases in New England were compared with 385 matched population controls, identified by random-digit dialing, and 337 cases residing within the United States were compared with 800 sibling controls. In the population-based comparison, estimated relative risks (RRs) of uveal melanoma, after adjustment for other factors, were elevated for the following: ancestry from more northern latitudes with a substantially elevated risk for Northern European ancestry (RR, 6.5; 95% confidence interval [CI], 1.9 to 22.4) and more than a twofold risk for British ancestry (RR, 2.4; 95% CI, 1.1 to 5.1), as compared with Southern European or other Mediterranean heritage; light skin color as compared with dark (RR, 3.8; 95% CI, 1.1 to 12.6); and 10 or more cutaneous nevi as compared with none (RR, 2.7; 95% CI, 1.5 to 4.9). There was a statistically significant trend for increasing risk with more northern heritage and more moles. Southern residence (below latitude 40 degrees N) for more than 5 years also increased risk (RR, 2.8; 95% CI, 1.1 to 6.9), as compared with none. In both comparisons, use of sunlamps was a risk determinant (RR, 3.4; 95% CI, 1.1 to 10.3 with random-digit dialed controls and RR, 2.3; 95% CI, 1.2 to 4.3 with sibling controls, comparing occasional or frequent use to never use), as was intense sun exposure (RR, 1.7; 95% CI, 0.9 to 3.0 and RR, 2.1; 95% CI, 1.4 to 3.2, respectively). However, birthplace below latitude 40 degrees N and outdoor work were associated with a lower risk.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1990

In search of cochlear morphologic correlates for tinnitus.

A correlative study was made of the cochlear pathologic features existing in the temporal bones of 83 subjects with a clinical history of tinnitus and 33 without tinnitus. None of 24 types of pathologic change assessed by light microscope occurred in more than 40% of tinnitus cases; nor was the prevalence of any of these pathologic changes significantly greater in subjects with tinnitus compared with control subjects. For five types of morphologic alteration the prevalence was significantly greater among control subjects compared with tinnitus cases, but this is interpreted cautiously because of the challenge in retrospectively selecting an appropriate control group. Under the conditions of the study, that is, using light-microscopic techniques on tissues obtained post mortem, we could not identify a pathologic correlate for tinnitus.

Aged↗

PubMed1990

White blood cell count as a predictor of mortality: results over 18 years from the Normative Aging Study.

The ubiquitous white blood cell count (WBC) has rarely been analyzed as a predictor of future mortality. We examined WBC measured in prospective examinations of 2011 initially healthy men in the Normative Aging Study (mean age 47.5), followed for an average of 13.6 years with 27,402 man-years of observation. Between 1970 and 1987, 183 participants died. Mortality rates for men with baseline WBC over 9000 were 12.2/1000 man-years, 1.8-2.5 times those of men with lower WBC in each of three age groups. Proportional hazards models controlling for established risk factors including age, systolic blood pressure, cholesterol and smoking status, found WBC at the baseline exam to be an independent predictor of mortality over the following years. Even within the normal range, a difference of 1000 in the initial WBC increased the risk ratio by 1.2 (95% CI 1.1, 1.3). The relation of initial WBC to mortality was not affected by baseline age, body mass index (BMI), smoking or blood pressure. These findings are not explained by medication effects. We conclude that the WBC is an independent predictor of all-cause mortality.

Adult↗

PubMed1990

Relative survival rates after alternative therapies for uveal melanoma.

Survival in a group of 556 patients with uveal melanoma treated by proton beam irradiation with a median follow-up of 5.3 years was compared with that of 238 patients enucleated during the same 10-year period as irradiated patients (July 1975 to December 1984) with a median follow-up of 8.8 years, and 257 patients enucleated during the preceding 10 years (January 1965 to June 1975) with a median follow-up of 17.0 years. Adjustments were made for known prognostic factors including age, tumor location, tumor height, and clinical estimate of tumor diameter (for enucleated patients this was estimated in a regression equation relating histologic to clinical measurement). The overall rate ratio for all cause mortality was 1.2 (95% confidence interval, 0.9-1.6) for the concurrent enucleation series versus proton beam, and 1.6 (95% confidence interval, 1.2-2.1) for the earlier enucleation series versus proton beam. Relative rates of metastatic death, cancer death, and all cause mortality comparing alternative treatments were found to vary with time after treatment. Interval-specific rate ratios were evaluated using proportional hazards models fitted to separate time intervals after treatment. For all three outcomes, rate ratios were over two and statistically significant for the first 2 years after treatment and closer to one and nonsignificant after year 6 comparing the two enucleation groups with proton beam. Results suggest that treatment choice has little overall influence on survival in patients with uveal melanoma.

Adult↗

PubMed1990

Case-control study of idiopathic retinal detachment.

A case-control study of idiopathic, rhegmatogenous retinal detachment (IRD) was conducted to investigate potential risk factors for developing IRD. These included some factors reported previously, such as cardiovascular disease, and some not under suspicion, such as cigarette smoking and iris colour. Cases (n = 198) were incident cases of IRD who were hospitalized for surgical repair of their detachments. Controls (n = 655) were patients hospitalized for conditions unrelated to suspected risk factors for IRD. The risk of IRD appeared to increase with increasing age, and the relative risk for self-reported myopes, compared with non-myopes, was elevated (RR = 3.4, 95% CI = 2.3 - 5.0). The relative risk of IRD was decreased in current smokers (RR = 0.5, 95% CI = 0.3 - 0.8); although there was not a significant trend of decreasing relative risk with increasing amount smoked, the estimate was lowest in those who smoked most heavily. Risk did not appear to be related to gender, eye colour, history of myocardial infarction, or history of hypertension.

Adolescent↗

PubMed1990

Idiopathic sudden sensorineural hearing loss and postnatal viral labyrinthitis: a statistical comparison of temporal bone findings.

Although the cause of idiopathic sudden sensorineural hearing loss remains uncertain, a viral origin has been suggested in many cases on the basis of anamnestic microbiologic and pathologic data. Twenty-two temporal bone specimens from 18 patients who during life suffered a sudden partial or complete sensorineural hearing loss were studied. On the basis of clinical data, these cases were assigned to one of three diagnostic categories, and the temporal bones were studied by light microscopy and serial section analysis. The implications of the histopathologic findings for the pathogenesis of idiopathic sudden sensorineural hearing loss are discussed.

Adult↗

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↗