Rita Hiller

Senile Lens Changes and Diabetes in two Population Studies

Clinical and epidemiologic studies of the association between senile cataract and diabetes have produced what initially appears to be conflicting evidence. Three studies of extracted cataract have found a positive association in persons less than 70 years old. Conversely, two studies of senile lens changes (including aphakia) reported no association with diabetes. These apparently disparate findings led to the hypothesis that the diseases are in fact not associated, but that diabetics are more likely to be referred to ophthalmologists and therefore to have cataracts removed. We tested this hypothesis with data from two population surveys, the Framingham Eye Study and the Health and Nutrition Examination Survey (HANES). Both studies showed a marked excess prevalence of senile cataract (including aphakia) in diabetics less than 65 years old (relative risks of 4.02 and 2.97, respectively). Beyond the age of 64 years, the HANES study but not the Framingham study showed an excess prevalence, although it was less marked (relative risks of 1.63 and 1.02, respectively). For senile lens changes other than cataract, both studies showed little, if any, association with diabetes. Our results for cataract (whether removed or not) were generally consistent with those of previous studies of extracted cataract for persons under the age of 70 years and for persons aged 70 years or more. The two studies that reported no association between lens changes and diabetes provided information inadequate to support or refute the foregoing findings. The various studies failed to support increased referral of diabetics to ophthalmologists as an explanation for the observed association. All these studies found the association in persons less than 70 years old, whether the cataract had been removed or not.

Risk factors for hemiretinal vein occlusion : Comparison with risk factors for central and branch retinal vein occlusion the eye disease case-control study

OBJECTIVE Possible risk factors for hemiretinal vein occlusion were identified and compared with risk factor profiles for central and branch retinal vein occlusion. DESIGN The design was a multicenter case-control study. METHODS The authors identified 79 patients with hemiretinal vein occlusion (HRVO), 258 patients with central retinal vein occlusion (CRVO), 270 patients with branch retinal vein occlusion (BRVO), and 1142 control subjects at 5 clinical centers. Risk factor data were obtained through interviews, clinical examinations, and laboratory analyses of blood specimens. RESULTS Systemic hypertension and history of diabetes mellitus were associated with increased risk of HRVO. Risk of CRVO increased with history of diabetes, systemic hypertension, and higher erythrocyte sedimentation rate (females only); risk of CRVO decreased with increasing amounts of physical activity and increasing amounts of alcohol consumption. Systemic hypertension, higher body mass index, and higher alpha2-globulin levels were associated with increased risk of BRVO, whereas higher high-density lipoprotein levels and increasing levels of alcohol consumption were associated with decreased risk of BRVO. Glaucoma history was associated with all three types of retinal vein occlusion. CONCLUSION Patients presenting with retinal vein occlusion should be evaluated for cardiovascular disease, diabetes, and glaucoma.

The Prevalence of Nuclear, Cortical, and Posterior SubcapsuIar Lens Opacities in a General Population Sample

Data from the 1973 to 1975 Framingham Eye Study were used to estimate the prevalence rates of nuclear, cortical, and posterior subcapsular lens opacities in persons between ages 52 and 85 years. The rates for each of the opacities increased rapidly with age, so that for the oldest age group, 75 years and over, nuclear, cortical, and posterior subcapsular opacities were found in 65.5%, 27.7% and 19.7% of persons, respectively. Nuclear opacities were the most commonly diagnosed lens change. Each of the opacities was found more often in women than in men. Among persons with senile lens changes, the proportion with more than one type of change increased from 26.5% for ages 52 to 64 years, to 47.1% for ages 75 to 85 years. The high prevalence rates for senile lens opacities (over 75% for persons aged 75 to 85 years) and the frequent occurrence of opacities in combination create methodological problems for epidemiologic studies of lens opacities.

Blindness from Glaucoma

We observed an overall ratio of 8:1 for nonwhite to white primary glaucoma blindness. Our fragmentary evidence suggested that the ratio of underlying disease, that is, nonblinding glaucoma or intraocular pressure differentials, may be closer to 2:1 than 8:1 as between nonwhites and whites. The remaining four fold differential can be explained by a combination of the following: more complete reporting for nonwhites, reporting for medical care later in the disease than whites, and poorer response to treatment for nonwhites compared to whites. The trend of new blindness from glaucoma for recent years was stationary in the United States, England, and Wales.

A longitudinal study of body mass index and lens opacities: The Framingham studies

OBJECTIVE The purpose of the study was to determine whether body mass index (BMI) is an independent risk factor for the development of nuclear, cortical, or posterior subcapsular lens opacities. DESIGN A cohort study. PARTICIPANTS AND METHODS Eye examinations were conducted on surviving members of the Framingham Heart Study Cohort from 1973 to 1975 (Framingham Eye Study I) and again from 1986 to 1989 (Framingham Eye Study II). Data from the Framingham Heart Study, including weight measurements collected biennially from 1948, were used to examine associations between BMI (mean BMI across examinations, slope of BMI over time, and fluctuations in BMI) and the development of lens opacities. This analysis included 714 individuals, aged 52-80 years, who were free of lens opacities at the first eye examination. MAIN OUTCOME MEASURES Development of nuclear, cortical, and posterior subcapsular lens opacities. RESULTS A total of 444 persons developed lens opacities during the approximately 13 years between eye examinations. In logistic regression analyses that controlled for age, sex, education, diabetes, and smoking, the risk of developing cortical opacity increased with higher BMI at the time of the first eye examination (P = 0.002). Risk of cortical opacities also increased, at a borderline level of significance, with higher average BMI (P = 0.09) across examinations and increasing BMI levels over time (P = 0.10). There was a strong association between increasing BMI over time and the development of posterior subcapsular lens opacities (P = 0.002). No associations were found for nuclear lens opacities. CONCLUSIONS Although the mechanism explaining the association is unclear, these findings suggest that BMI, a potentially modifiable characteristic, is associated with the development of cortical and posterior subcapsular lens opacities.

High intraocular pressure and survival: the Framingham studies☆

PURPOSE To examine whether high intraocular pressure (greater than or equal to 25 mm Hg) or a history of treatment for glaucoma is associated with decreased survival and, if so, how such ocular markers might be explained. METHODS Eye examinations, including applanation tonometry, were conducted on members of the Framingham Eye Study cohort from February 1, 1973, to February 1, 1975. Participants who reported a history of treatment for glaucoma were identified. Survival data, including information on the date of death, were available from the time of the Eye Study through March 31, 1990. RESULTS Of the 1,764 persons under the age of 70 years at the baseline eye examination, 1,421 persons had low intraocular pressure (< or =20 mm Hg), 264 persons had medium intraocular pressure levels (20 to 24 mm Hg), and 79 persons had high intraocular pressure (> or =25 mm Hg) or history of glaucoma treatment. During the follow-up period, 29%, 30%, and 47% died in the groups with low, medium, and high intraocular pressure (or history of glaucoma treatment), respectively. In an age-and-sex adjusted Cox proportional hazards analysis, the death rate ratio for the group with medium intraocular pressure relative to the group with low intraocular pressure was 1.04. The corresponding death rate ratio for the group with high intraocular pressure was 1.56 with a 95% confidence interval of 1.11 to 2.19 (P < .001). After adjustment for age, sex, hypertension, diabetes, cigarette smoking, and body mass index, a positive relationship remained, but at a borderline level of significance (P = .075). CONCLUSIONS High intraocular pressure or the presence of glaucoma is a marker for decreased life expectancy in the Framingham Eye Study cohort. The relationship is present even after adjustment for risk factors known to be associated with higher mortality such as age, sex, hypertension, diabetes, cigarette smoking, and body mass index. Special attention to the general health status of patients with high intraocular pressure or glaucoma seems warranted.

Serum lipids and age-related lens opacities: A longitudinal investigation: The Framingham studies

OBJECTIVE To investigate whether serum lipid/lipoprotein levels are independent risk factors for nuclear, cortical, or posterior subcapsular (PSC) cataracts. DESIGN Case-control study nested in a cohort study. PARTICIPANTS AND METHODS Eye examinations were conducted on surviving members of the Framingham Offspring Heart Study cohort from 1989 to 1991 (Framingham Offspring Eye Study) to determine cataract case-control status. Data from the Framingham Offspring Heart Study, including fasting serum total cholesterol, high-density lipoprotein cholesterol, and triglyceride measurements collected first in 1971, again approximately 8 years later, and approximately every 4 years thereafter were used to examine associations between lipid levels (mean levels across examinations and slope of measurements over time) and the presence of specific cataract types. The multistage analyses included 1869 persons aged 45 years and older. MAIN OUTCOME MEASURES A standardized grading system was used to grade cortical, nuclear, and PSC cataracts. RESULTS The median age of participants was 55 years; 49% were males. In multivariable logistic regression models adjusted for potential confounders, fasting hypertriglyceridemia (>/=250 mg/dl) was associated with an increased risk of PSC cataract in men (P = 0.02). High-density lipoprotein cholesterol levels </=35 mg/dl were associated with PSC cataract in men at a borderline level of significance (P = 0.09). No associations were noted between serum lipid/lipoprotein variables and risk of cortical or nuclear cataract. CONCLUSIONS These findings suggest that hypertriglyceridemia, a potentially modifiable factor, is associated with the development of PSC cataract in men.

Serum zinc and serum lipid profiles in 778 adults

There has been increasing use of high-dosage zinc supplementation in the population, in particular as a potential treatment for age-related macular degeneration. We examined the relationship between fasting serum zinc and serum lipid levels in 778 adults, aged 22 to 80 years, who were control subjects in a multicenter, clinic-based case-control study. The samples were taken during 1987 to 1990, a time when vitamin/mineral supplementation was becoming increasingly common. We found that higher serum zinc levels, most notably those above the highest quintile, were associated with higher levels of total serum cholesterol, low-density-lipoprotein cholesterol, and triglycerides. No significant trend was noted for high-density-lipoprotein cholesterol. Previous studies demonstrated that high-dosage zinc supplements raise serum zinc levels. The possibility that use of such supplements can adversely affect serum lipid profiles suggests that chronic ingestion of such supplements should not be done without adequate medical supervision.

ASSOCIATIONS OF TYPES OF LENS OPACITIES BETWEEN AND WITHIN EYES OF INDIVIDUALS: An application of Second‐order Generalized Estimating Equations

The lens opacity characteristics of individuals constitute multivariate data. Our goal was to estimate the associations between the three main types of age-related lens opacities (nuclear, cortical, posterior subcapsular) both between and within eyes of individuals using cross-sectional data from the Framingham (Massachusetts) Eye Studies. We describe use of a recently proposed extension of the generalized estimating equations approach to marginal logistic models (GEE2), and we demonstrate that a variety of research problems can be investigated with this methodology. For example, in our data, there were strong associations of the same opacity types between the two eyes of individuals and weak associations between different types of opacities. We also note that estimation of such associations may be limited in other epidemiologic settings.