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Purpose-Optical coherence tomography (OCT) is a new technology that uses near-infrared light in an interferometer to produce approximately 10-μm resolution cross-sectional images of the tissue of interest. The authors performed repeated quantitative assessment of nerve fiber layer thickness in individuals with normal and glaucomatous eyes, and they evaluated the reproducibility of these measurements. Methods-The authors studied 21 eyes of 21 subjects by OCT. Each subject underwent five repetitions of a series of scans on five separate occasions within a 1-month period. Each series consisted of three circular scans around the optic nerve head (diameters, 2.9, 3.4, and 4.5 mm). Each series was performed separately using internal (fixation with same eye being studied) and external (fixation with contralateral eye) fixation techniques. The eye studied and the sequence of testing were assigned randomly.Results-Internal fixation (IF), in general, provides a slightly higher degree of reproducibility than external fixation (EF). Reproducibility was better in a given eye on a given visit than from visit to visit. Reproducibility as measured by intraclass correlation coefficients were as follows: circle diameter (CD), 2. Conclusions-Nerve fiber layer thickness can be reproducibly measured using OCT. Internal is superior to external fixation; each circle diameter tested provides adequate reproducibility.Optical coherence tomography (OCT) is a new technology that allows cross-sectional imaging of the eye using light. This technology is noncontact and noninvasive and may have use in diagnosing and managing retinal disease and glaucoma. We previously reported on the quantification of nerve fiber layer (NFL) and retinal thickness using OCT; however, for this technology to provide meaningful data, measurements must be reproducible.The goal of this study is to determine the reproducibility of measurements of NFL and retinal thickness made by OCT. We also sought to evaluate the optimal circle diameter for OCT NFL

Objective To examine how a healthy lifestyle is related to life expectancy that is free from major chronic diseases. Design Prospective cohort study. Setting and participants The Nurses’ Health Study (1980-2014; n=73 196) and the Health Professionals Follow-Up Study (1986-2014; n=38 366). Main exposures Five low risk lifestyle factors: never smoking, body mass index 18.5-24.9, moderate to vigorous physical activity (≥30 minutes/day), moderate alcohol intake (women: 5-15 g/day; men 5-30 g/day), and a higher diet quality score (upper 40%). Main outcome Life expectancy free of diabetes, cardiovascular diseases, and cancer. Results The life expectancy free of diabetes, cardiovascular diseases, and cancer at age 50 was 23.7 years (95% confidence interval 22.6 to 24.7) for women who adopted no low risk lifestyle factors, in contrast to 34.4 years (33.1 to 35.5) for women who adopted four or five low risk factors. At age 50, the life expectancy free of any of these chronic diseases was 23.5 (22.3 to 24.7) years among men who adopted no low risk lifestyle factors and 31.1 (29.5 to 32.5) years in men who adopted four or five low risk lifestyle factors. For current male smokers who smoked heavily (≥15 cigarettes/day) or obese men and women (body mass index ≥30), their disease-free life expectancies accounted for the lowest proportion (≤75%) of total life expectancy at age 50. Conclusion Adherence to a healthy lifestyle at mid-life is associated with a longer life expectancy free of major chronic diseases.

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A B S T R A C T PurposeAnimal and in vitro studies suggest that aspirin may inhibit breast cancer metastasis. We studied whether aspirin use among women with breast cancer decreased their risk of death from breast cancer. MethodsThis was a prospective observational study based on responses from 4,164 female registered nurses in the Nurses' Health Study who were diagnosed with stages I, II, or III breast cancer between 1976 and 2002 and were observed until death or June 2006, whichever came first. The main outcome was breast cancer mortality risk according to number of days per week of aspirin use (0, 1, 2 to 5, or 6 to 7 days) first assessed at least 12 months after diagnosis and updated. ResultsThere were 341 breast cancer deaths. Aspirin use was associated with a decreased risk of breast cancer death. The adjusted relative risks (RRs) for 1, 2 to 5, and 6 to 7 days of aspirin use per week compared with no use were 1.07 (95% CI, 0.70 to 1.63), 0.29 (95% CI, 0.16 to 0.52), and 0.36 (95% CI, 0.24 to 0.54), respectively (test for linear trend, P Ͻ .001). This association did not differ appreciably by stage, menopausal status, body mass index, or estrogen receptor status. Results were similar for distant recurrence. The adjusted RRs were 0.91 (95% CI, 0.62 to 1.33), 0.40 (95% CI, 0.24 to 0.65), and 0.57 (95% CI, 0.39 to 0.82; test for trend, P ϭ .03) for 1, 2 to 5, and 6 to 7 days of aspirin use, respectively. ConclusionAmong women living at least 1 year after a breast cancer diagnosis, aspirin use was associated with a decreased risk of distant recurrence and breast cancer death.

Purpose-To evaluate the hypothesis that macular thickness correlates with the diagnosis of glaucoma.Design-Cross-sectional study.Participants-We studied 367 subjects (534 eyes), including 166 eyes of 109 normal subjects, 83 eyes of 58 glaucoma suspects, 196 eyes of 132 early glaucoma patients, and 89 eyes of 68 advanced glaucoma patients.Methods-We used optical coherence tomography (OCT) to measure macular and nerve fiber layer (NFL) thickness and to analyze their correlation with each other and with glaucoma status. We used both the commercial and prototype OCT units and evaluated correspondence between measurements performed on the same eyes on the same days. Main Outcome Measure-Macular and NFL thickness as measured by OCT.Results-All NFL parameters both in prototype and commercial OCT units were statistically significantly different comparing normal subjects and either early or advanced glaucoma (P < 0.001). Inner ring, outer ring, and mean macular thickness both in prototype and commercial OCT devices were found to be significantly different between normal subjects and advanced glaucomatous eyes (P < 0.001). The outer ring was the only macular parameter that could significantly differentiate between normal and early glaucoma with either the prototype or commercial OCT unit (P = 0.003, P = 0.008, respectively). The area under the receiver operator characteristic (AROC) curves comparing mean NFL thickness between normal and advanced glaucomatous eyes was 1.00 for both the prototype and commercial OCT devices for eyes scanned on both machines on the same day. The Reprint requests to Joel S. Schuman, MD, New England Eye Center, Tufts University School of Medicine, 750 Washington St, Box 450, Boston, MA 02111. Joel S. Schuman and Gadi Wollstein shared equal parts in the preparation of the manuscript.Presented in part at the American Academy of Ophthalmology (AAO), Orlando, Florida, 1999. NIH Public Access Author ManuscriptOphthalmology. Author manuscript; available in PMC 2007 August 15. Published in final edited form as:Ophthalmology. 2003 January ; 110(1): 177-189. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author ManuscriptAROC comparing mean macular thickness in normal and advanced glaucomatous eyes scanned on both machines on the same day was 0.88 for the prototype OCT device and 0.80 for the commercial OCT.Conclusions-Both macular and NFL thickness as measured by OCT showed statistically significant correlations with glaucoma, although NFL thickness showed a stronger association than macular thickness. There was good correspondence between findings using both the prototype and commercial OCT units. Macular and NFL thickness measurements made with OCT may have usefulness in the clinical assessment of glaucoma.Glaucoma is a process in which a loss of retinal ganglion cells (RGCs) results in characteristic optic nerve and visual field abnormalities. Detection of glaucomatous damage is typically through observation of the optic nerve head and retinal nerve fiber layer (NFL) and measurem...

The concept of the population attributable risk (PAR) percent has found widespread application in public health research. This quantity describes the proportion of a disease which could be prevented if a specific exposure were to be eliminated from a target population. We present methods for obtaining point and interval estimates of partial PARs, where the impact on disease burden for some presumably modifiable determinants is estimated in, and applied to, a cohort study. When the disease is multifactorial, the partial PAR must, in general, be used to quantify the proportion of disease which can be prevented if a specific exposure or group of exposures is eliminated from a target population, while the distribution of other modifiable and non-modifiable risk factors is unchanged. The methods are illustrated in a study of risk factors for bladder cancer incidence (Michaud DS et al., New England J Med 340 (1999) 1390). A user-friendly SAS macro implementing the methods described in this paper is available via the worldwide web.

Few studies have examined whether activity and adiposity levels typical of American women affect their risk of ovulatory disorder infertility, and none has examined moderate and vigorous intensity exercise separately. We investigated these associations in the Nurses' Health Study II, comparing prospectively collected data on adiposity and activity for 830 cases of incident ovulatory infertility and 26,125 pregnancies. We observed a U-shaped association between body mass index (BMI) and relative risk of ovulatory infertility, with increased risk for BMI below 20.0 or above 24.0 kg/m2. On the basis of the BMI distribution of U.S. women, these findings suggest that 12% (95% confidence interval = 7-20%) of ovulatory infertility in the U.S. may be attributable to underweight (BMI <20.0) and 25% (95% CI = 20-31%) to overweight (BMI > or = 25.0). An increase in vigorous activity (but not moderate activity) was associated with reduced relative risk of ovulatory infertility. Each hour per week of vigorous activity was associated with a 7% (95% CI = 4-10%) lower relative risk of ovulatory infertility. After adjustment for BMI, a 5% (95% CI = 2-8%) reduction in relative risk per hour of weekly activity remained. These data suggest that, among American women, more ovulatory infertility is attributable to overweight and a sedentary lifestyle than to underweight and overexertion.