Age-related eye disease, quality of life, and functional activity

OBJECTIVE

To examine the associations of measures of quality of life (Medical Outcomes Study Short Form Health Survey) and functional activities (activities of daily living, instrumental activities of daily living, and visual function) in persons with and without age-related eye diseases.

METHODS

Two thousand, six hundred seventy persons participated in the 1998 through 2000 examinations of both the Beaver Dam Eye Study and the Epidemiology of Hearing Loss Study. Age-related eye disease (age-related maculopathy, cataract, diabetic retinopathy, glaucoma, macula edema, occlusions, amblyopia, and macular holes) were assessed by fundus, slitlamp, and retroilluminated photographs and self-reported ocular history. Also administered was a standard interview that included the Medical Outcomes Study Short Form Health Survey, activities of daily living, instrumental activities of daily living, and visual function questionnaires and information on other medical conditions.

RESULTS

After controlling for age and sex, we found that persons with an age-related eye disease had decreased scores in almost all the domains of the Medical Outcomes Study Short Form Health Survey, and persons with eye disease in both eyes had poorer scores than persons with eye disease in only 1 eye. Stratifying by age-related maculopathy and central cataract yielded similar results. Further adjustment for current visual acuity and the number of comorbid conditions explained most associations. Several of the mental scales were still marginally significantly lower (P<.10) in persons with age-related maculopathy after adjustment. Persons with an age-related eye disease were not more likely to have impaired activities of daily living or instrumental activities of daily living. After adjustment for current visual acuity and number of comorbidities, persons who had trouble reading small print or recognizing people across the street were more likely to have an age-related eye disease. Otherwise, there were no significant associations with the visual function questions and any of the specific ocular conditions.

CONCLUSIONS

Many measures of general quality of life and functional activities were related to age-related eye diseases, but few associations remained significant after adjustments for vision and other comorbidities. Our data are compatible with the notion that decreased visual function, irrespective of the pathologic reason for the decrease, is associated with diminished quality of life and functional activities of living.

Local and Global Geometric Influence on Steady Flow in Distal Anastomoses of Peripheral Bypass Grafts

We consider the effect of geometrical configuration on the steady flow field of representative geometries from an in vivo anatomical data set of end-to-side distal anastomoses constructed as part of a peripheral bypass graft. Using a geometrical classification technique, we select the anastomoses of three representative patients according to the angle between the graft and proximal host vessels (GPA) and the planarity of the anastomotic configuration. The geometries considered include two surgically tunneled grafts with shallow GPAs which are relatively planar but have different lumen characteristics, one case exhibiting a local restriction at the perianastomotic graft and proximal host whilst the other case has a relatively uniform cross section. The third case is nonplanar and characterized by a wide GPA resulting from the graft being constructed superficially from an in situ vein. In all three models the same peripheral resistance was imposed at the computational outflows of the distal and proximal host vessels and this condition, combined with the effect of the anastomotic geometry, has been observed to reasonably reproduce the in vivo flow split. By analyzing the flow fields we demonstrate how the local and global geometric characteristics influences the distribution of wall shear stress and the steady transport of fluid particles. Specifically, in vessels that have a global geometric characteristic we observe that the wall shear stress depends on large scale geometrical factors, e.g., the curvature and planarity of blood vessels. In contrast, the wall shear stress distribution and local mixing is significantly influenced by morphology and location of restrictions, particular when there is a shallow GPA. A combination of local and global effects are also possible as demonstrated in our third study of an anastomosis with a larger GPA. These relatively simple observations highlight the need to distinguish between local and global geometric influences for a given reconstruction. We further present the geometrical evolution of the anastomoses over a series of follow-up studies and observe how the lumen progresses towards the faster bulk flow of the velocity in the original geometry. This mechanism is consistent with the luminal changes in recirculation regions that experience low wall shear stress. In the shallow GPA anastomoses the proximal part of the native host vessel occludes or stenoses earlier than in the case with wide GPA. A potential contribution to this behavior is suggested by the stronger mixing that characterizes anastomoses with large GPA.

Polygenic effects and cigarette smoking account for a portion of the familial aggregation of nuclear sclerosis

Cataract is the most common cause of blindness worldwide. Nuclear cataract, an advanced stage of nuclear sclerosis, is the most common type of age-related cataract. The authors assessed data from 2,089 persons within 620 extended pedigrees who participated in the 1988-1990 Beaver Dam Eye Study in Wisconsin to determine whether the observed familial aggregation of nuclear sclerosis could be explained by inheritance of a major gene. Familial correlations were examined and segregation analyses were performed on nuclear sclerosis measurements adjusted for age, sex, and pack-years of cigarette smoking. There was modest correlation among close family members after adjustment for age, sex, and pack-years of cigarette smoking: 0.084 between parents and offspring, and 0.198 between sibling pairs. Although results do not support involvement of a single major locus in the etiology of nuclear sclerosis, models that allowed for familial correlation, attributable in part to polygenic effects, did provide a better fit to the observed data than models without a polygenic effect. This finding suggests that several genes of modest effect may influence development of nuclear lens opacity, possibly in conjunction with environmental factors. Cigarette smoking was an important covariate in these analyses. Overall, results highlight the complex etiology of nuclear sclerosis.

Detecting Progression of Nuclear Sclerosis by Using Human Grading Versus Semiautomated Computer Grading

PURPOSE

To assess indices of nuclear sclerosis derived from digitized images made from color (slide) photographs.

METHODS

Film-based slit lamp images taken at baseline and at 5- and 10-year follow-up examinations of the Beaver Dam Eye Study cohort were digitized, and optical traces were taken along an axis through the center of the cornea and lens. Four indices of the severity of sclerosis were calculated based on the optical densities. The associations of the original Beaver Dam grades and these indices to age, vision, and change in severity of sclerosis over two subsequent visits were compared.

RESULTS

At baseline photographs, the Spearman correlation between age and severity was 0.65 for the original film-based grading (n = 4518 right eyes) and varied between 0.46 and 0.71 for the measures from digitized images. Correlations of the indices to visual acuity were 0.38 for the film-based grading and ranged from 0.32 to 0.38 for the other indices. The authors assume that nuclear sclerosis does not regress and the percentage of regression is a reflection of error in grading. The percentage of regression and progression of sclerosis over 5- and 10-year intervals was determined for each index. After 5 years, 48.2% progressed and 4.9% regressed, using the Beaver Dam grades; progression occurred in 4.9% to 9.9%, and regression occurred in 4.5% to 7.0% for the other indices. After 10 years, 61.9% progressed and 3.2% regressed using the Beaver Dam grades; progression occurred in 8.0% to 19.7%, and regression occurred in 2.6% to 9.7% for the other indices.

CONCLUSIONS

Semiautomated grading of the digitized images can be used to process thousands of images with little oversight by a trained grader. Indices of sclerosis that closely parallel human grading in their relationships to age and visual acuity can be easily computed. However, the indices appear to identify significantly less progression of nuclear sclerosis than does human grading. Further development to define a useful metric for identifying severity and progression of nuclear sclerosis is needed.

A genetic contribution to intraocular pressure: the beaver dam eye study

PURPOSE

To investigate a potential genetic contribution to intraocular pressure (IOP), we performed a complex segregation analysis on 2337 individuals in 620 extended pedigrees ascertained through a population-based cohort, the Beaver Dam Eye Study (BDES). IOP is a principal risk factor for primary open-angle glaucoma (POAG) a leading cause of blindness worldwide.

METHODS

Segregation analysis is an analytical method that provides statistical evidence supporting the involvement of a major gene or polygenes in a particular phenotype. Detailed medical histories and eye examinations were performed on all participants. From the two eyes, the higher IOP measurement was used as a continuous trait after adjustment for covariates. A genome-wide scan (GWS) using affected sib pair linkage analysis was performed on 218 sibling pairs.

RESULTS

In this segregation analysis the model that allowed for an unmeasured major environmental effect plus a polygenic/multifactorial effect provided the best fit and was the most parsimonious model. The lack of an adequate fit for the Mendelian single-gene models is consistent with a multifactorial model of inheritance that may include multiple genes and environmental factors that contribute to IOP. The results of the GWS yielded two novel loci as potential linkage regions for IOP on chromosomes 6 (P = 0.008) and 13 (P = 0.0007). Neither of these regions has previously been identified in GWS of POAG.

CONCLUSIONS

The segregation and familial correlation analyses of IOP suggest a polygenetic component with environmental influences. The pilot linkage study further confirms the heterogeneity of IOP with the identification of two novel genetic loci.

Support for Polygenic Influences on Ocular Refractive Error

PURPOSE

Refractive errors, myopia, and hyperopia are common conditions requiring corrective lenses. The familial clustering of myopia has been well established. Several chromosomal regions have been linked to high myopia (12q, 17q, and 18q), to quantitative refraction among twins (3q, 4q, 8p, and 11p), and to families with moderate myopia (22q). This study examined the familial aggregation and pattern of inheritance of ocular refraction in an adult population, by using data from the Beaver Dam Eye Study.

METHODS

Familial correlations were examined and segregation analysis was performed on the average refractive error measurements in the right and left eyes after adjustment for age, sex, and education. Analyses were based on 2138 individuals in 620 extended pedigrees with complete data on age, sex, education, and spherical equivalent.

RESULTS

Substantial positive correlation was found between siblings (0.33), parents and offspring (0.17), and cousins (0.10) and lower correlation among avuncular pairs (0.08) after adjustment for age, sex, and years of education. The results of this segregation analysis do not support the involvement of a single major locus throughout the entire range of refractive error. However, models allowing for familial correlation, attributable in part to polygenic effects, provided a better fit to the observed data than models without a polygenic component, suggesting that several genes of modest effect may influence refractive error, possibly in conjunction with environmental factors.

CONCLUSIONS

These results support the involvement of genetic factors in the etiology of refractive error and are consistent with reports of linkage to multiple regions of the genome.

Familial Aggregation of Retinal Vessel Caliber in the Beaver Dam Eye Study

PURPOSE

To describe familial correlations of retinal vessel measurements.

METHODS

A standardized examination and interview was administered to a population-based cohort of adults aged 43-86 years. Blood pressure was measured, and family relationships, current smoking status, and photographs of the retina were obtained. Computer-assisted grading was done to determine central retinal arteriole (CRAE) and venule equivalents (CRVE), and the arteriole-to-venule ratio (AVR) was computed. Familial correlations were calculated using FCOR in the SAGE software package. Analysis was done on the right eye measures for 871 sibling, 341 parent-child, 1362 cousin, 554 avuncular, and 887 spousal pairs.

RESULTS

After adjustment for age, gender, mean arterial blood pressure, and current smoking status, the correlations (and 95% confidence interval) between siblings for the CRVE, CRAE, and AVR were 0.23 (0.16, 0.31), 0.20 (0.12, 0.28) and 0.13 (0.05, 0.20), respectively. Parent-child correlations were very similar, and the avuncular correlations were about half as great. The cousin correlations were about half the avuncular correlations. Spousal correlations of 0.03, 0.04, and 0.01 for CRVE, CRAE, and AVR, respectively, were not significantly different from 0.

CONCLUSIONS

Retinal vessel equivalents were more highly correlated between relatives than between unrelated individuals. The relative magnitudes of these correlations were likely the result of shared genes. Because the vessel measurements have been shown to be predictive of cardiovascular and other systemic diseases, understanding the determinants of these familial relationships could have important health benefits.

Identification of a major locus for age-related cortical cataract on chromosome 6p12-q12 in the Beaver Dam Eye Study

Age-related cataracts are one of the leading causes of visual impairment and blindness among the elderly worldwide. Among age-related cataracts, cortical opacities rank as the second most common type; however, little is known about their molecular pathogenesis or genetics. To identify susceptibility loci for cortical cataracts, we genotyped a subset of families (102 families; n = 224 sib pairs) from the Beaver Dam Eye Study and performed a model-free genome-wide linkage analysis for markers linked to a quantitative measure of cortical opacity. We obtained evidence for linkage at marker D1S1622 on chromosome 1p35 (P < 0.0002) and at marker D6S1053 on 6q12 (P < 0.00008) in the initial scan. Five additional regions on 1q31, 2p24, 2q11, 4q28, and 15q13 that are suggestive of linkage (P < or = 0.01 or logarithm of the likelihood ratio > or = 1.18) were observed. The region on chromosomes 6p12-q12 was selected for fine mapping, and the intermarker distance was reduced to 3 cM by adding 11 markers in the interval between D6S1017 and D6S1021. After fine mapping, significant evidence of linkage remained on chromosome 6p12-q12 at D6S1053 (P < 0.00005). The current genome scan for age-related cortical cataracts may lead to identification of novel genes, because few regions identified in the current scan have previously been implicated in congenital or age-related cataracts.

The comparability of estimates of retroilluminated lens opacities as judged from film-based and digital imaging

PURPOSE

Neitz film-based retroillumination cameras, the standard for documenting retroilluminated lens opacities for epidemiologic studies, are no longer produced. A digital imaging system is now available for imaging these opacities. We sought to compare gradings of images from both systems.

DESIGN

Comparison of technique.

METHODS

One hundred fourteen lenses were imaged with both systems and graded according to protocols. Concordance between the methods was compared using kappa statistics.

RESULTS

There was moderate concordance for cortical opacities (kappa = 0.63) and good concordance for posterior subcapsular opacities (kappa = 0.83). Grades from digital images slightly underestimated the frequency and severity of cortical cataract.

CONCLUSION

Digital imaging of retroilluminated lens opacities results in similar classification of the severity of opacities. It will be useful for epidemiologic studies of cortical (CC) and posterior subcapsular cataracts (PSC).

Location of lesions associated with age-related maculopathy over a 10-year period: the Beaver Dam Eye Study

PURPOSE

To describe cumulative incidence and changes in retinal lesions associated with age-related maculopathy (ARM) by location over a 10-year period and to examine the relation of location of those lesions to progression of ARM.

METHODS

Persons ranging in age from 43 to 84 years and living in Beaver Dam, Wisconsin, at the time of a census (1987-1988) were examined two to three times over a 10-year period (n = 3684). Drusen area, size, and type; retinal pigment epithelium depigmentation; increased pigment; geographic atrophy; and neovascular macular degeneration were determined in each of nine macular subfields: central, inner and outer superior, inner and outer nasal, inner and outer inferior, and inner and outer temporal by grading of stereoscopic color fundus photographs. Late ARM was defined as presence of either geographic atrophy or neovascular ARM.

RESULTS

Lesions were more likely to change or develop in specific locations. Drusen area increased most in the central circle. Compared with other quadrants, drusen greater than 125 micro m in diameter and soft indistinct or reticular drusen were most likely to develop in the superior or temporal quadrants, whereas pigmentary abnormalities were most likely to occur in the nasal or superior quadrants. In general, large drusen, soft indistinct drusen, and pigmentary abnormalities were more likely to develop in the inner circle versus the central and outer circles. The quadrant location of early ARM lesions in 72 persons in whom late ARM developed was generally similar to that in persons who did not have late ARM. However, persons who had geographic atrophy were more likely to have large drusen in the inner circle than in the outer circle, while those who did not have late ARM were more likely to have large drusen in the outer circle.

CONCLUSIONS

Lesions associated with early ARM were more likely to develop in specific locations in the macular area, and persons with lesions closer to the fovea may be related to a higher risk of development of late ARM. The quadrant location of early ARM lesions does not appear to add additional information to the risk of development of late ARM.

The prevalence of refractive errors among adults in the United States, Western Europe, and Australia

OBJECTIVE

To estimate the prevalence of refractive errors in persons 40 years and older.

METHODS

Counts of persons with phakic eyes with and without spherical equivalent refractive error in the worse eye of +3 diopters (D) or greater, -1 D or less, and -5 D or less were obtained from population-based eye surveys in strata of gender, race/ethnicity, and 5-year age intervals. Pooled age-, gender-, and race/ethnicity-specific rates for each refractive error were applied to the corresponding stratum-specific US, Western European, and Australian populations (years 2000 and projected 2020).

RESULTS

Six studies provided data from 29 281 persons. In the US, Western European, and Australian year 2000 populations 40 years or older, the estimated crude prevalence for hyperopia of +3 D or greater was 9.9%, 11.6%, and 5.8%, respectively (11.8 million, 21.6 million, and 0.47 million persons). For myopia of -1 D or less, the estimated crude prevalence was 25.4%, 26.6%, and 16.4% (30.4 million, 49.6 million, and 1.3 million persons), respectively, of whom 4.5%, 4.6%, and 2.8% (5.3 million, 8.5 million, and 0.23 million persons), respectively, had myopia of -5 D or less. Projected prevalence rates in 2020 were similar.

CONCLUSIONS

Refractive errors affect approximately one third of persons 40 years or older in the United States and Western Europe, and one fifth of Australians in this age group.

Variation associated with measurement of retinal vessel diameters at different points in the pulse cycle

BACKGROUND/AIMS

To assess the variability in retinal vessel measurements at different points in the pulse cycle.

METHODS

A healthy white male aged 19 years had 30 digitised images taken at three distinct points in the pulse cycle over a one hour period. A pulse synchronised ear clip trigger device was used to capture images at the desired point in the pulse cycle. Two trained graders measured the retinal vessel diameter of one large arteriole, one large venule, one small arteriole, and one small venule 10 times in each of these 30 images.

RESULTS

Within an image, variability was similar between graders, pulse point, and vessel type. Across images taken at the same point in the pulse period, the change from the minimum to maximum measurement was between 6% and 17% for arterioles and between 2% and 11% for venules. In addition, measurements of small vessels had greater changes than large vessels and no point in the pulse period was more variable than another. Ignoring pulse cycle increased variability across images in the large venule, but not in the other vessel types. Mixed effect models were fit for each of the vessel types to determine the greatest source of variability. Controlling for pulse point and grader, the largest source of variability for all four vessels measured was across images, accounting for more than 50% of the total variability.

CONCLUSION

Measurements of large retinal venules is generally less variable than measurements of other retinal vessels. After controlling for pulse point and grader, the largest source of variation is across images. Understanding the components of variability in measuring retinal vessels is important as these techniques are applied in epidemiological studies.

Heritability of risk factors for primary open-angle glaucoma: the Beaver Dam Eye Study

PURPOSE

To investigate the family aggregation and heritability of risk indicators of primary open-angle glaucoma.

METHODS

During the baseline examination of the Beaver Dam Eye Study, standardized measurements of intraocular pressure were performed with a Goldmann applanation tonometer. Stereoscopic photographs of the optic discs were taken of both eyes of each study participant. The eyes were graded for the size of the optic disc and cup according to a standardized protocol, with graders masked to other subject characteristics. Family members who had participated in the examination phase were identified.

RESULTS

Correlations in sibling pairs (n = 1136), parent-child pairs (n = 514), and cousin pairs (n = 1807) for intraocular pressure were 0.17, 0.18, and 0.12, respectively and were all statistically significant, whereas the spouse pair correlation was not. Correlations for sibling, parent-child, and avuncular pairs were higher for vertical optic disc, vertical optic cup, and vertical cup-to-disc ratio than for intraocular pressure. Heritability estimates were 0.36, 0.55, 0.57, and 0.48 for intraocular pressure, optic cup diameter, optic disc diameter, and cup-to-disc ratio, respectively. Correlations for the optic disc parameters were compatible with the amount of gene sharing in relative pairs of different degrees.

CONCLUSIONS

Risk indicators of open-angle glaucoma correlate highly in families, and the patterns are consistent with the hypothesis of genetic determinants of these factors.

Dissection of genomewide-scan data in extended families reveals a major locus and oligogenic susceptibility for age-related macular degeneration

To examine the genetic basis of age-related macular degeneration (ARMD), a degenerative disease of the retinal pigment epithelium and neurosensory retina, we conducted a genomewide scan in 34 extended families (297 individuals, 349 sib pairs) ascertained through index cases with neovascular disease or geographic atrophy. Family and medical history was obtained from index cases and family members. Fundus photographs were taken of all participating family members, and these were graded for severity by use of a quantitative scale. Model-free linkage analysis was performed, and tests of heterogeneity and epistasis were conducted. We have evidence of a major locus on chromosome 15q (GATA50C03 multipoint P=1.98x10-7; empirical P< or =1.0x10-5; single-point P=3.6x10-7). This locus was present as a weak linkage signal in our previous genome scan for ARMD, in the Beaver Dam Eye Study sample (D15S659, multipoint P=.047), but is otherwise novel. In this genome scan, we observed a total of 13 regions on 11 chromosomes (1q31, 2p21, 4p16, 5q34, 9p24, 9q31, 10q26, 12q13, 12q23, 15q21, 16p12, 18p11, and 20q13), with a nominal multipoint significance level of P< or =.01 or LOD > or =1.18. Family-by-family analysis of the data, performed using model-free linkage methods, suggests that there is evidence of heterogeneity in these families. For example, a single family (family 460) individually shows linkage evidence at 8 loci, at the level of P<.0001. We conducted tests for heterogeneity, which suggest that ARMD susceptibility loci on chromosomes 9p24, 10q26, and 15q21 are not present in all families. We tested for mutations in linked families and examined SNPs in two candidate genes, hemicentin-1 and EFEMP1, in subsamples (145 and 189 sib pairs, respectively) of the data. Mutations were not observed in any of the 11 exons of EFEMP1 nor in exon 104 of hemicentin-1. The SNP analysis for hemicentin-1 on 1q31 suggests that variants within or in very close proximity to this gene cause ARMD pathogenesis. In summary, we have evidence for a major ARMD locus on 15q21, which, coupled with numerous other loci segregating in these families, suggests complex oligogenic patterns of inheritance for ARMD.

Familial aggregation of components of the multiple metabolic syndrome in the Framingham Heart and Offspring Cohorts: Genetic Analysis Workshop Problem 1

Background

The multiple metabolic syndrome is defined by a clustering of risk factors for cardiovascular disease. We sought to evaluate the familial correlations of the components of the syndrome using data from the Framingham Heart Study original and offspring cohorts as provided for the Genetic Analysis Workshop 13. Measures of plasma cholesterol (total and HDL), body mass index (BMI), and systolic blood pressure were used from selected calendar years of exams. Familial correlations were calculated using FCOR in S.A.G.E.

Results

The sibling correlations were relatively high for all measures and exams, from 0.17 for systolic blood pressure to 0.27 for HDL cholesterol. The parent-child correlations were very similar, except for systolic blood pressure. The avuncular correlations were much smaller and the cousin correlations were even smaller. For HDL cholesterol the avuncular correlation was half the sibling correlation and the cousin correlation was half that again. Spousal correlations ranged from 0.07 for systolic blood pressure to 0.34 for BMI. Correlations were somewhat lower from 1984 to 1987 examinations than from 1971 to 1975 examinations, except for spousal correlations for systolic blood pressure and BMI.

Conclusion

The results of the family pair correlations are suggestive of genetic determinants of lipid levels and BMI. These components have been shown to be predictive of cardiovascular disease as well as diabetes. Genes in common with each of the components might also influence development of cardiovascular disease and diabetes, both complex diseases.

Revised formulas for summarizing retinal vessel diameters

Background/Purpose. Recent findings suggest that an objective assessment of retinal vessel caliber from fundus photographs provide information about the association of microvascular characteristics with macrovascular disease. Current methods used to quantify retinal vessel caliber, introduced by Parr(1,2) and Hubbard,(3) are not independent of scale and are affected by the number of vessels. To improve upon these methods we introduce revised formulas for quantifying vessel caliber. Methods. Revised formulas were estimated using retinal vessel measurements from 44 young adults free of hypertension and diabetes. Comparisons between the two methods were done using digitized photographs from 4926 participants at the baseline examination of the Beaver Dam Eye Study (BDES), an ongoing population-based cohort study initiated in 1987. Individual arterioles and venules were measured using semi-automated computer software from which summary measures were calculated. Results. Correlation coefficients between the Parr-Hubbard and revised formulas were high (Pearson correlation coefficients ranging from 0.94 to 0.98). Both arteriolar and venular caliber significantly increased with an increasing number of vessels measured using the Parr-Hubbard formulas (p < 0.001), which in turn affected the relationship to mean arterial blood pressure. To the contrary, the revised formulas were not affected by the number of measured vessels (p > 0.50). Conclusions. We describe revised formulas for summarizing retinal vessel diameters measured from fundus photographs to be used in future studies and analyses. The revised formulas correlate highly with the previously used Parr-Hubbard formulas, but offer the advantages of being more robust against variability in the number of vessels observed, being independent of image scale, and being easier to implement.

Socioeconomic and lifestyle factors and the 10-year incidence of age-related cataracts

PURPOSE

To investigate the association of socioeconomic and lifestyle factors with incidence of age-related cataracts.

DESIGN

Population-based longitudinal epidemiologic study.

METHODS

Persons aged 43 to 86 years (n = 4,926) living in Beaver Dam, Wisconsin, were examined in 1988 to 1990, 1993 to 1995, and 1998 to 2000. Medical histories were obtained, and photographs of the lenses were taken at each visit. Photographs were graded according to standard protocols.

RESULTS

Socioeconomic and lifestyle factors considered were income, education, occupation, smoking, alcohol, caffeine, and multivitamin use. After adjustment for age and sex, income (or education) was inversely and smoking was directly related to the 10-year cumulative incidence of nuclear cataract. None of the factors were significantly associated with incident cortical or posterior subcapsular cataract. We found no evidence in these analyses to suggest that history of multivitamin use altered the relationships of smoking to the incidence of cataracts. In models adjusting for all other significant risk factors, the individual significance values for each individual factor differed little from the models adjusting only for age and sex.

CONCLUSIONS

Incident nuclear cataract was associated with income and smoking 10 years earlier. There were no significant lifestyle exposures associated with incident cortical and posterior subcapsular cataract.

Microencapsulation of lipid nanoparticles containing lipophilic drug

A polymeric emulsion bead, which consists of core and capsule, was prepared. The core is composed of lipid nanoparticles containing lipophilic drug and semi-interpenetrating networks (semi-IPNs) are prepared to provide the capsule composed of sodium alginate and hydroxypropylmethyl cellulose (HPMC). The lipid nanoparticles were encapsulated into the polymeric emulsion bead with high drug loading efficiency, and lovastatin was used as a model drug. For the application as an oral drug delivery system, the enteric coating was performed with polymeric emulsion bead. The drug release pattern was controlled by the composition of capsule materials and environmental pH.

A whole-genome screen of a quantitative trait of age-related maculopathy in sibships from the Beaver Dam Eye Study

Age-related maculopathy (ARM) is a leading cause of visual impairment among the elderly in Western populations. To identify ARM-susceptibility loci, we genotyped a subset of subjects from the Beaver Dam (WI) Eye Study and performed a model-free genomewide linkage analysis for markers linked to a quantitative measure of ARM. We initially genotyped 345 autosomal markers in 325 individuals (N=263 sib pairs) from 102 pedigrees. Ten regions suggestive of linkage with ARM were observed on chromosomes 3, 5, 6, 12, 15, and 16. Prior to fine mapping, the most significant regions were an 18-cM region on chromosome 12, near D12S1300 (P=.0159); a region on chromosome 3, near D3S1763, with a P value of.0062; and a 6-cM region on chromosome 16, near D16S769, with a P value of.0086. After expanding our analysis to include 25 additional fine-mapping markers, we found that a 14-cM region on chromosome 12, near D12S346 (located at 106.89 cM), showed the strongest indication of linkage, with a P value of.004. Three other regions, on chromosomes 5, 6, and 15, that were nominally significant at P< or =.01 are also appropriate for fine mapping.

Associations of selected medications and visual function: the Beaver Dam Eye Study

AIM

To investigate association of drug use and visual function.

METHODS

A cross sectional population based study was carried out on participants in the 1993-5 examination phase of the Beaver Dam Eye Study. All drugs in current use by study participants were recorded. Performance based and self assessed visual functions were obtained at the time of the study evaluation. The main outcome measure was the relation of levels of visual functions by use of specific drugs.

RESULTS

Many classes of drugs were associated with decreases in at least two performance based visual functions. For example, high blood pressure drugs were significantly associated with poorer best corrected visual acuity, poorer near vision, and poorer contrast sensitivity (p<0.001 for all). Patterns of association for self assessed visual functions were not as strong. However, use of glaucoma drops and benzodiazepines were associated with poorer self assessed visual functions in most circumstances cited.

CONCLUSIONS

Many commonly used medications are inversely associated with visual functions in a middle and older aged population. This may influence the ability to perform complex tasks and quality of life.

Associations of visual function with physical outcomes and limitations 5 years later in an older population: the Beaver Dam eye study

PURPOSE

To examine the association of performance-based measures of visual functioning with the occurrence of falls, fractures, physical outcomes, and limitations in an older population.

DESIGN

A population-based study of Beaver Dam, Wisconsin, of persons who were 43 to 86 years of age was performed from 1988 through 1990 (n = 4926), 1993 through 1995 (n = 3722), and 1998 through 2000 (n = 2962).

PARTICIPANTS

Participants in the Beaver Dam Eye Study at the 1993 through 1995 examination.

METHODS

Historical information was obtained by interview at each examination. Current binocular visual acuity, best-corrected visual acuity, near acuity, log contrast sensitivity, and visual sensitivity (threshold) were measured by standard protocols at the 5-year follow-up (1993-1995) of the cohort. Outcomes were ascertained at the 10-year follow-up examination (1998-2000).

MAIN OUTCOME MEASURES

History of physical limitations, falls, fractures, and change in time to walk a measured course.

RESULTS

The incidence of outcomes was as follows: nursing home residence, 4.6%; not driving at night, 9.7%; any fracture, 11.0%; two or more falls, 7.5%; fear of falling, 11.9%; and use of walking aids, 3.6%. The increase in time to walk a 10-foot course was 0.14 seconds. Age was associated with higher incidence of virtually every outcome and with time to walk a measured course. Incidence of not driving at night, any fracture, and fear of falling were more common in women after adjusting for age. We evaluated the relationship of outcomes to current binocular vision, best-corrected vision, near vision, contrast sensitivity, and visual sensitivity (threshold), as measured by perimetry (the latter four for the better eye). When controlling for confounders in multivariable models, the odds ratios of nursing home placement for the poorest categories of function were 3.20 (95% confidence interval [CI], 1.85, 5.56) for current binocular vision, 4.23 (95% CI, 2.34, 7.64) for best-corrected visual acuity in the better eye, 5.00 (95% CI, 2.28, 10.94) for near vision, and 2.40 (95% CI, 1.46, 3.92) for contrast sensitivity. The odds ratio for not driving at night for the poorest category of visual sensitivity was 2.22 (95% CI, 1.31, 3.75). The odds ratios for any fractures for the categories of poorest function were 1.75 (95% CI, 1.02, 2.99) for current binocular acuity, 2.00 (95% CI, 1.10, 3.62) for best-corrected vision in the better eye, 3.04 (95% CI, 1.34, 6.86) for near vision, and 1.64 (95% CI, 1.05, 2.56) for visual sensitivity. The odds ratios for 2 or more falls in the past year for the poorest categories of visual function were 2.02 (95% CI, 1.13, 3.63) for current binocular acuity and 1.85 (95% CI, 1.10, 3.12) for visual sensitivity. The incidence of fear of falling was associated with the poorest category of best-corrected acuity (odds ratio, 2.95; 95% CI, 1.52, 5.70), and use of walking aids was associated with visual sensitivity (odds ratio, 3.51; 95% CI, 1.72, 7.18). Change in time to walk the measured course was not significantly associated with any of the visual functions.

CONCLUSIONS

Visual function is associated with some physical outcomes and limitations 5 years later in middle- to older-aged adults. These associations are likely to be related, in part, to the presence of other medical conditions.

Do multiple families alter estimates of risk for age-related cataract in a population-based study? The Beaver Dam Eye Study

We sought to determine the effect of "genetic" load on the strengths of risk factors for age-related cataracts in the population-based Beaver Dam Eye Study. Of the 4,926 participants in the baseline examination in 1988 to 1990, 2,338 were members of 594 family groups. There were no important differences in the risks due to pack-years smoked, systolic and diastolic blood pressures, body mass index, current smoking, hypertension or hormone replacement therapy for either the whole population or subgroups created by omitting siblings or any family relation. There were some differences when the analyses were limited to only a randomly selected family member or a randomly selected sibling. These latter findings may relate to the older average age of those in sibships or in families compared to those not in families. We conclude that for the associations we explored, the relatively large number of families in our population had little effect on the strengths of the risk factors, and that limiting analyses to only those not in families may distort risk factor associations by altering the age structure in this population.

Late clinical and magnetic resonance imaging follow up of Nipah virus infection

The Nipah virus is a newly identified paramyxovirus responsible for an outbreak of fatal encephalitis in Malaysia and Singapore. This paper reports the follow up clinical and magnetic resonance imaging findings in 22 affected subjects. Of 13 patients with encephalitis, one died, one was lost to follow up, and seven recovered. Among the four remaining patients, one had residual sixth nerve palsy, another suffered from severe clinical depression, and a third patient had evidence of retinal artery occlusion. One patient with delayed onset Horner syndrome had a single lesion in the cervical spinal cord. The brain magnetic resonance findings were stable or improved in nine patients over 18 months of follow up. Among a second group of nine asymptomatic seropositive abattoir workers, magnetic resonance examination in seven subjects revealed discrete small lesions in the brain; similar to those detected in encephalitis patients. These findings suggest that in addition to encephalitis, the newly discovered Nipah virus affects the spinal cord and the retina. Late clinical and radiological findings can occur in Nipah virus infections as with other paramyxoviruses.

Relationship of measures of frailty to visual function: the Beaver Dam Eye Study

PURPOSE

To investigate the association of standard measures of frailty to visual acuity and contrast sensitivity.

METHODS

Time to walk a measured course, handgrip strength, peak expiratory flow rate, ability to stand from a sitting position without using arms, best-corrected visual acuity, and contrast sensitivity were assessed at the third examination (1998-2000) of the Beaver Dam Eye Study. The study is population-based with the initial census in 1988-1990.

RESULTS

All measures of frailty and vision were significantly associated with age (poorer function at older ages). In general, women had poorer function than men in each age category. An "index of frailty" consisting of highest quartile (slowest) gait time, lowest quartile of peak expiratory flow rate, lowest quartile of handgrip strength, and inability to stand from sitting in one try (for those not in a wheelchair) was constructed for women and men. A score of 0 was the minimum amount of frailty, while a score of 4 indicated the maximum amount. Controlling for age, those with no evidence of frailty (score = 0) were likely to have the best visual acuity and best contrast sensitivity, while those with maximum evidence of frailty (score = 4) were likely to have poorest visual acuity and contrast sensitivity.

CONCLUSION

Greater frailty was associated with poorer visual functions. Including a measure of visual function when assessing frailty may improve upon the usefulness of an index of frailty in predicting incidence of chronic systemic diseases and survival.

Refractive errors, intraocular pressure, and glaucoma in a white population

OBJECTIVE

To examine the relation of refractive errors to glaucoma and intraocular pressure (IOP) in a defined white population.

DESIGN

Population-based cross-sectional and follow-up study.

PARTICIPANTS

Persons aged 43 to 86 years living in Beaver Dam, Wisconsin (n = 4926).

METHODS

All participants received a standardized assessment of refraction, IOP, and glaucoma at baseline (1988-1990), with IOP remeasured 5 years later (1993-1995). Refraction was defined at baseline as follows: myopia as spherical equivalent of -1.00 diopters (D) or less, emmetropia as -0.75 to +0.75 D, and hyperopia as +1.00 D or more.

MAIN OUTCOME MEASURES

Relation of baseline refraction to prevalent glaucoma (defined from IOP, optic disc, and visual field criteria) and incident ocular hypertension (defined as IOP more than 21 mmHg at the 5-year examination in eyes with IOP of 21 mmHg or less at baseline).

RESULTS

A myopic refraction was correlated with increasing IOP at baseline (P < 0.001). After controlling for age and gender, persons with myopia were 60% more likely to have prevalent glaucoma than those with emmetropia (odds ratio [OR], 1.6; 95% confidence interval [CI], 1.1, 2.3). In contrast, controlling for age, gender, and baseline IOP, persons with hyperopia were 40% more likely to have incident ocular hypertension than those who were emmetropic at baseline (OR, 1.4; 95% CI, 1.0, 2.0). Myopia was not related to incident ocular hypertension.

CONCLUSIONS

In these population-based data, there was a cross-sectional association of myopia with higher IOP and prevalent glaucoma. Similar associations have been found in previous studies. Hyperopia may be associated with 5-year risk of ocular hypertension, a finding that needs further investigation.

Incidence of age-related cataract over a 10-year interval: the Beaver Dam Eye Study

OBJECTIVE OR PURPOSE: To describe the cumulative incidence of age-related cataracts and cataract surgery over a 10-year interval.

DESIGN

Prospective epidemiologic study.

PARTICIPANTS

Persons 43 to 86 years of age participating in the Beaver Dam Eye Study (n = 4926 at baseline, 2764 for baseline, 5-year and 10-year follow-ups).

METHODS

Questionnaires and examinations were performed according to standardized protocols in a clinic setting in the town of Beaver Dam, Wisconsin. Lens photographs were obtained with specially modified cameras and were graded according to codified rules by trained graders.

MAIN OUTCOME MEASURES

Nuclear, cortical, and posterior subcapsular cataracts and cataract surgery.

RESULTS

In right eyes, incident nuclear cataract occurred in 19.4%, cortical cataract in 17.4%, posterior subcapsular cataract in 6.1%, and cataract surgery in 10.8%. Incidence increased for all end points with age. Women had significantly higher incidences of nuclear cataract and cataract surgery than men. Time trends seem to be influencing the incidence of cataract surgery.

CONCLUSIONS

Age-related cataracts are common events in aging. Age-specific cataract surgery incidence seems to be increasing.

Components of the metabolic syndrome and risk of cardiovascular disease and diabetes in Beaver Dam

OBJECTIVE

To determine whether components of the metabolic syndrome precede the 5-year incidence of cardiovascular disease and diabetes.

RESEARCH DESIGN AND METHODS

A population of individuals aged 43-84 years was evaluated from 1988 to 1990 and again 5 years later. Medical history, blood pressure, and laboratory measures were obtained at both examinations following the same protocols. Subjects without diabetes were classified according to level of glycemia, high blood pressure, high-risk lipid levels, high uric acid levels, and proteinuria at baseline. History of incident myocardial infarction, angina, stroke, and diabetes was obtained at follow-up.

RESULTS

Of the 4,423 subjects without diabetes, 6.9% had elevated levels of glycemia, 18.4% had high blood pressure, 82.7% had high-risk lipid levels (either high serum total cholesterol or low HDL cholesterol or high ratio of these two levels), 27% had elevated uric acid levels, 33.2% had high BMI, and 3.3% had proteinuria (> or =30 mg/dl). The risk of incident cardiovascular disease 5 years later increased with the number of the components present; 2.5% of those with one component developed cardiovascular disease, whereas 14.9% of those with four or more components developed cardiovascular disease. Of those with one component, diabetes developed in 1.1% 5 years later, whereas diabetes developed in 17.9% of those with four or more components.

CONCLUSIONS

Components of the metabolic syndrome are common and are associated with incident cardiovascular disease and diabetes after 5 years. Interventions to alter BMI, lipid levels, and blood pressure may decrease incident diabetes and cardiovascular disease.

Changes in refraction over 10 years in an adult population: the Beaver Dam Eye study

PURPOSE

To quantify the 10-year change in refraction in persons more than 40 years of age.

METHODS

All people 43 to 84 years of age and living in Beaver Dam, Wisconsin, in 1988 were invited for a baseline examination (1988-1990), a 5-year follow-up examination (1993-1995), and a 10-year follow-up examination (1998-2000). Refractions were determined according to the same protocol at all examinations. Aphakic and pseudophakic eyes and eyes with best corrected visual acuity of 20/200 or worse were excluded. After exclusions, refraction data were available on 2362 right eyes of the 2937 people examined at baseline and 10-year follow-up.

RESULTS

Age was related to the direction and amount of change in refraction. Spherical equivalent became more positive in the youngest subjects and more negative in the oldest. After adjustment for the severity of nuclear sclerosis and other factors, the 10-year change in refraction was +0.48, +0.03, and -0.19 D for persons 43 to 59, 60 to 69 and 70+ years of age at the baseline examination, respectively. Severity of nuclear sclerosis was also strongly related to amount of change. Those with mild nuclear sclerosis at baseline had a change of +0.35 D, whereas those with severe nuclear sclerosis had a change of -0.53 D. The amount of change was also related to diabetes and weakly related to baseline refractive error, but was unrelated to gender and education. In addition to the longitudinal changes observed, there was a birth cohort effect. In comparing people of the same age across examinations, those born in more recent years had more myopia than those born in earlier years.

CONCLUSIONS

Significant changes in spherical equivalent in adults occur over a 10-year period. Younger people became more hyperopic, whereas older people became more myopic. These data provide evidence of a longitudinal change in refraction in adults, which may explain the refractive patterns observed in cross-sectional studies.

Reactive oxygen species activity, mucosal lipoperoxidation and glutathione in Helicobacter pylori-infected gastric mucosa

BACKGROUND AND AIM

Helicobacter pylori is considered as the major pathogen in Helicobacter pylori-associated gastroduodenal disease, but the mechanism of its action has not been fully explained. This study was performed to assess the reactive oxygen species activity and the damage in Helicobacter pylori-infected gastric mucosa.

METHODS

Gastric biopsy specimens were obtained from 308 patients undergoing endoscopy. Gastric mucosal damage was assessed by using luminol enhanced chemiluminescence, thiobarbituric acid-reactive substance, and mucosal glutathione.

RESULTS

The chemiluminescence and thiobarbituric acid-reactive substance-equivalent levels in the mucosa of patients with Helicobacter pylori-positive gastric mucosa (43.8 +/- 134.9 c.p.m./microg tissue, 157.0 +/- 96.2 nmol/g tissue, respectively) were significantly higher than in those with Helicobacter pylori-negative mucosa (6.8 +/- 20.3 c.p.m./microg tissue, 110.0 +/- 51.6 nmol/g tissue, respectively; P=0.000, P=0.016, respectively). The glutathione levels in the mucosa of patients with Helicobacter pylori-positive gastric mucosa (159.3 +/- 76.6 nmol/microg tissue) were significantly lower than in those with Helicobacter pylori-negative gastric mucosa (212.3 +/- 134.3 nmol/microg tissue; P=0.008). After the data were divided according to the presence of Helicobacter pylori, there were no significant differences in chemiluminescence, thiobarbituric acid-reactive substance, and glutathione among the different macroscopic findings within Helicobacter pylori-positive and -negative gastric mucosa.

CONCLUSIONS

Helicobacter pylori infection plays a pathological role in many gastrointestinal diseases through excessive mucosal-reactive oxygen species production, pronounced membrane damage, and the depletion of gastric anti-oxidants.

Aggregation of refractive error and 5-year changes in refractive error among families in the Beaver Dam Eye Study

OBJECTIVE

To examine aggregation of refraction, myopia, hyperopia, and astigmatism, as well as the 5-year change in each of these measures, among adult family members.

DESIGN

Geographically defined, population-based cohort study in Beaver Dam, Wis. Participants were all 43 to 84 years of age in 1988. Family relationships among participants of the study were identified through interviews. The main outcome measures were noncycloplegic refractions. Aggregation was assessed by Pearson correlations and odds ratios (ORs) that both members of a pair were affected.

RESULTS

Age-adjusted sibling correlation of refraction was 0.37 and the OR for a sibling to be myopic was 4.18, whereas the OR for being hyperopic was 2.87 (all statistically significant, P<.05). Correlations and ORs for parent-child and cousin relationships were smaller, and those for spousal relationships were not significant. Correlations and ORs for cylinder power and astigmatism were not statistically significant for most relationships considered. There were no statistically significant correlations or ORs for changes in any measure of refractive error.

CONCLUSIONS

The strong aggregation of refractive error, including myopia and hyperopia, among siblings along with weaker associations among parent-child and cousin pairs and no associations among spouses suggest a potential genetic influence on refractive error. There is no such suggestion for a genetic influence on the changes in refraction or in cylinder power and astigmatism.

Changes in visual acuity in a population over a 10-year period : The Beaver Dam Eye Study

PURPOSE

To describe the change in visual acuity in a 10-year period.

DESIGN

Population-based cohort study.

PARTICIPANTS

Included 3684 persons 43 to 86 years of age at the time of a baseline examination in 1988 to 1990, living in Beaver Dam, Wisconsin, at a follow-up examination in 1993 to 1995 and/or 1998 to 2000.

METHODS

Best-corrected visual acuity was measured, after refraction, with logarithm of the minimum angle of resolution charts using a modification of the Early Treatment Diabetic Retinopathy Study protocol.

MAIN OUTCOMES MEASURES

Doubling of the visual angle and incidence of visual impairment.

RESULTS

The change in the mean number of letters read correctly over the 10-year period varied in the right eye from -0.9 (standard deviation [SD] = 5.5) and in the left eye from -1.2 (SD = 6.6) in people between 43 and 54 years of age to -11.0 (SD = 20.0) in the right eye and -12.6 (SD = 20.4) in the left eye in people 75 years of age or older (n = 184) at baseline. Over the 10-year period, 5.9% of the population had impaired vision (20/40 or worse in the better eye) develop, 0.8% had severe visual impairment (20/200 or worse in the better eye) develop, 4.8% had doubling of the visual angle, and 3.9% had improved vision. People who were 75 years of age or older at baseline were 15.0 times (95% confidence interval [CI], 10.9-20.6; P < 0.001) as likely to have impaired vision develop, 9.3 times (95% CI, 6.5-13.3; P < 0.001) as likely to have doubling of the visual angle, and 19.8 times as likely (95% CI, 8.4-46.4; P < or = 0.001) to have severe visual impairment develop than people younger than 75 years of age at baseline. For the 82 persons 75 years of age or older, currently residing in a nursing or group home at follow-up, they were 2.6 times (95% CI, 1.45-4.52) as likely to have impaired vision develop, 1.6 times (95% CI, 0.47-5.62) as likely to have severely impaired vision develop, and 3.6 times (95% CI, 1.96-6.78) as likely to have had a doubling of the visual angle than those not residing in a nursing or group home at follow-up.

CONCLUSIONS

These data provide precise population-based estimates of the 10-year incidence of loss of vision over a wide spectrum of ages and show that decreased visual acuity in people 75 years of age after 10 years is a common finding, especially in those who are admitted to nursing or group homes.

Measures of obesity and age-related eye diseases

OBJECTIVE

To compare body mass index with waist-to-hip ratio as correlates of age-related eye disease.

DESIGN

Population-based cross-sectional study.

PARTICIPANTS

Participants of the Beaver Dam Eye Study at 5-year follow-up examinations.

METHODS

Body mass index was computed from weight and height, and waist-to-hip ratio was computed from measurements all done at the 5-year examination. Presence of ocular lesions was based on gradings of standard photographs of the retina and lens.

MAIN OUTCOME MEASURES

Presence of early and late age-related maculopathy and nuclear, cortical, and posterior subcapsular cataracts.

RESULTS

In women, early age-related maculopathy was significantly associated with both body mass index and waist-to-hip ratio. The relationship between waist-to-hip ratio and late age-related maculopathy was of borderline significance. When analyzed as continuous measures, waist-to-hip ratio was more strongly associated with nearly every outcome compared to body mass index. In men, there was little difference between body mass index and waist-to-hip ratio as correlates of age-related eye diseases. The reason for differences between men and women is not clear, but is unlikely to be due to current exposure to estrogen.

CONCLUSIONS

In women in our analyses, waist-to-hip ratio is more strongly associated with age-related eye disease than is body mass index. When adiposity is considered as a risk factor itself, or as a confounder of risk factors for age-related ocular disease, waist-to-hip ratio may be the better measure to use in women.

Medication use and the 5-year incidence of early age-related maculopathy: the Beaver Dam Eye Study

OBJECTIVE

To evaluate incident early age-related maculopathy (ARM) after a 5-year interval with respect to medication use.

DESIGN

Population-based incidence study.

SETTING

Participants were adults aged 43 to 86 years living in Beaver Dam, Wis, when first examined in 1988-1990 (n = 4926); they were reexamined in 1993-1995 (n = 3684).

METHODS

All participants were examined and interviewed and stereoscopic color fundus photographs were taken. All procedures were done by standard protocol at both examinations. Incidence of ARM was based on grading using the Wisconsin ARM Grading System. All prescribed and over-the-counter medications in current use were brought to the examination site and the names were recorded at that time.

RESULTS

There were 678 drug preparations (active ingredients) being used at the baseline examination. No relations were found between most antihypertensive drugs, most central nervous system medications, aspirin and other nonsteroidal anti-inflammatory agents, estrogens, lipid-lowering agents, and incident early ARM over the 5-year period. Age- and sex-adjusted logistic regression analyses suggested possible associations (P<.10) between the use of phenothiazine antidopaminergics (odds ratio [OR], 2.83; 95% confidence interval [CI], 0.97-8.23; P =.06), desiccated thyroid hormones (OR, 2.32; 95% CI, 0.89-6.07; P =.09), and calcium channel blockers (OR, 1.70; 95% CI, 0.93-3.12; P =.08) with incident ARM. When additional information on past use was included in the regression model, the association remained for calcium channel blockers, but not for phenothiazines and desiccated thyroid hormones. A lower incidence of early ARM occurred in those who took antidepressants (OR, 0.34; 95% CI, 0.12-0.94; P =.04) at the baseline examination.

CONCLUSION

Although many different medications were being used at the baseline examination in the Beaver Dam Eye Study cohort, there were no striking associations with the 5-year incidence of early ARM.

Drug use and five-year incidence of age-related cataracts: The Beaver Dam Eye Study

OBJECTIVE

To evaluate incident cataract after a 5-year interval with respect to medication use.

DESIGN

Population-based incidence study.

MAIN OUTCOME

Incident cataract judged from standard photographs.

SETTING

Study subjects were adults 43 to 86 years of age in 1988 to 1990 and again in 1993 to 1995. All participants were examined and interviewed, and photographs were taken. All procedures and grading were done by protocols at both examinations. All medications in current use, prescribed as well as over-the-counter, were brought to the examination site, and the names were recorded at that time.

RESULTS

There were 678 drug preparations (active ingredients) being used at the baseline examination. Significantly lower incidences of nuclear cataracts 5 years later occurred in those who took thiazide diuretics (odds ratio [OR] = 0.79, 95% confidence interval [CI] 0.63, 1.00) and aspirin (OR = 0.76, 95% CI 0.61, 0.95) at the baseline examination. There were significantly more incident cortical cataracts in those taking oral steroids (OR = 2.59, 95% CI 1.45, 4.62), amitriptyline (OR = 2.03, 95% CI 1.09, 3.79), oral hypoglycemic agents (OR 2.06, 95% CI 1.23, 3.44), and insulin (OR = 3.38, 95% CI 1.61, 7.08). There were significantly more incident posterior subcapsular cataracts in those taking potassium-sparing diuretics (OR = 2.13, 95% CI 1.42, 3.18) and oral hypoglycemic agents (OR = 2.89, 95% CI 1.57, 5.33). Considering past use with never and current use did not alter the patterns of associations. We were not able to separate the effects of antihypertensive or diuretic agents from that of hypertension. However, hypoglycemic agents were no longer associated with any cataract type after stratifying by diabetes status.

CONCLUSIONS

Although many different medications were being used at the baseline examination in the Beaver Dam Eye Study cohort, few were associated with incident cataract. However, with the high frequency of use of medications and the possibility that effects of current exposure may occur in the future, it is reasonable to follow this and other older cohorts for the development of cataract.

Risk of incident age-related eye diseases in people with an affected sibling : The Beaver Dam Eye Study

The purpose of this investigation was to determine whether age-related cataract and maculopathy in older siblings predicts development of the same in younger siblings. A population-based study of age-related eye diseases was conducted in 1988--1990 in Beaver Dam, Wisconsin, and a follow-up examination was performed 5 years later. Diagnoses of age-related eye diseases were assigned on the basis of gradings of study photographs. There were 1,088 people from 488 sibships with at least two siblings who could contribute information for these analyses. The authors computed odds ratios and 95% confidence intervals for developing the specific lesion and identifying it 5 years later if an older sibling had it at baseline. The odds ratios were 1.65 (95% confidence interval (CI): 0.91, 2.99) for nuclear cataract, 1.62 (95% CI: 0.92, 2.85) for cortical cataract, 1.95 (95% CI: 0.48, 7.95) for posterior subcapsular cataract, 1.82 (95% CI: 0.91, 3.66) for soft drusen, 8.18 (95% CI: 3.34, 20.08) for retinal pigment epithelium depigmentation, 3.59 (95% CI: 1.71, 7.57) for increased retinal pigment, and 10.32 (95% CI: 0.83, 128.58) for exudative age-related maculopathy. These findings suggest that strong family determinants of lesions of age-related maculopathy are likely, less so for age-related cataract, which confer risk of the same lesion in a younger sibling.

Synchronization of single motor units during voluntary contractions in the upper and lower extremities

OBJECTIVE

To investigate motor unit synchronization in the time and frequency domains and compare the amount and nature of this synchronization between upper and lower extremity muscles in human subjects.

METHODS

A total of 120 motor unit pairs from biceps brachii (BB), first dorsal interosseous (1DI), vastus medialis (VM), and tibialis anterior (TA) on the dominant side were analyzed and compared. Pairs of motor unit spike trains were recorded from two concentric needle electrodes inserted within these muscles in healthy volunteers. Subjects were instructed to maintain a weak isometric contraction of these muscles so that an individual motor unit recorded from each concentric needle discharged at a steady rate of approximately 10 impulses/s. Pairs of motor unit spike trains were cross-correlated in the time domain, and coherence analysis in the frequency domain was performed on the same spike train data.

RESULTS

Synchronization was seen in all the muscles studied. Strength of motor unit synchronization, expressed as synchronization index (SI), was greater in 1DI muscles compared to other muscles (P<0.01). Coherence analysis revealed significant association between motor unit firings in the 1--5 and 25--30 Hz frequency ranges in all the muscles studied. The incidence of 25--30 Hz coherence peaks were found to be greater for 1DI muscles compared to other muscles.

CONCLUSION

The above results suggest a possible role for corticospinal projections in producing pre-synaptic inputs responsible for synchronization of motor unit firings and 25--30 Hz coherence peaks.

Clinical Features and Prognosis of Lung Cancer with Brain Metastasis

PURPOSE

Brain metastasis is estimated to occur in 20~40% of solid tumor patients and the most common primary tumor is lung cancer. Even though the prognosis of brain metastasis is grave and the 1-year survival rate is only 15%, symptom palliations are made with whole brain radiation therapy. We retrospectively evaluated the clinical features and prognostic factors of lung cancer with brain metastasis.

MATERIALS AND METHODS

From January 1987 to October 1999, 50 lung cancer patients with brain metastasis underwent whole brain radiation therapy. We reviewed the improvement in neurologic symptoms and survival according to the following parameters; performance status, histological type, presence of brain metastasis at the initial diagnosis of lung cancer, presence of extracranial metastasis, multiplicity of brain lesion, presence of primary lung symptom and treatment modalities.

RESULTS

The most frequent symptom with brain metastasis was a headache (50%). Palliation of the headache and other symptoms was achieved in 81% of the patients. Median overall survival after brain metastasis was 21 weeks and the 1 year survival rate was 15%. Patients without extracranial metastasis had a longer median survival than those with, 38 weeks versus 15 weeks, respectively (p=0.01).

CONCLUSION

In lung cancer with brain metastasis, neurologic symptoms can be palliated with whole brain radiation therapy, and in this study among such patients, absence of extracranial metastasis can be a good prognostic factor.

Refractive errors and incident cataracts: the Beaver Dam Eye Study

PURPOSE

To describe the relation between refractive errors and incident age-related cataracts in a predominantly white US population.

METHODS

All persons aged 43 to 84 years of age in Beaver Dam, Wisconsin, were invited for a baseline examination from 1988 through 1990 and a follow-up examination 5 years later from 1993 through 1995. At both examinations, participants had refraction and photographic assessment of cataract, according to a standardized protocol. Myopia was defined as a spherical equivalent of -1.0 diopters (D) or less, hyperopia as +1.0 D or more. The relations between refractive errors at baseline and cataract at baseline (prevalent cataract), 5-year incident cataract, and incident cataract surgery were analyzed by using generalized estimating equations.

RESULTS

When age and gender were controlled for, myopia was related to prevalent nuclear cataract (odds ratio [OR], 1.67; 95% confidence interval [CI], 1.23-2.27), but not to cortical and posterior subcapsular cataracts. Myopia was not related to 5-year incident nuclear, cortical, and posterior subcapsular cataracts, but was related to incident cataract surgery (OR 1.89; CI 1.18-3.04). Hyperopia was related to incident nuclear (OR 1.56; CI 1.25-1.95) and possibly cortical (OR 1.25; CI 0.96-1.63) cataracts, but not to posterior subcapsular cataract or cataract surgery. After further adjustment for diabetes, smoking, and education, the association between myopia and incident cataract surgery was attenuated (OR 1.60; CI 0.96-2.64), but the associations between hyperopia and incident nuclear and cortical cataracts were unchanged.

CONCLUSIONS

These data support the cross-sectional association between myopia and nuclear cataract seen in other population-based studies, but provide no evidence of a relationship between myopia and 5-year incident cataract. Hyperopia may be related weakly to incident nuclear and cortical cataract.

Reproductive exposures, incident age-related cataracts, and age-related maculopathy in women: the beaver dam eye study

PURPOSE

To evaluate the relationship of reproductive exposures and incident age-related cataract and maculopathy in women.

METHODS

This was a population-based cohort study including all adults 43 to 84 years of age living in Beaver Dam, Wisconsin (a representative midwestern community) who were identified during a census in 1987 to 1988. They were evaluated initially in 1988 to 1990 and at follow-up in 1993 to 1995. Evaluations included medical histories and both fundus and lens photography. All procedures were done according to protocols that were the same at both examinations. All photographs were graded by trained observers using defined grading schemes. The severities of age-related cataracts and maculopathy were determined by grading of photographs. Information on hormone exposures was ascertained from structured interviews.

RESULTS

After adjusting for age, the only significant finding for lens end points was a trend indicating a possible protective effect of increasing number of live births and incident posterior subcapsular cataract. There were no significant associations of any reproductive exposure with lesions of early or late age-related maculopathy.

CONCLUSIONS

In these population-based data, there is little evidence of association of hormone exposures with incident age-related eye disease in women 5 years later. Longer follow-up of this population, whose mean age is approaching that of heightened incidence, may disclose significant relationships.

Nipah viral encephalitis or Japanese encephalitis? MR findings in a new zoonotic disease

BACKGROUND AND PURPOSE

An epidemic of suspected Japanese encephalitis occurred in Malaysia in 1998-1999 among pig farmers. In neighboring Singapore, an outbreak occurred among pig slaughterhouse workers. It was subsequently established that the causative agent in the outbreak was not the Japanese encephalitis virus but a previously unknown Hendra-like paramyxovirus named Nipah virus.

METHODS

The brain MR images of eight patients with Nipah virus infection were reviewed. All patients tested negative for acute Japanese encephalitis virus. Seven patients had contrast-enhanced studies and six had diffusion-weighted examinations.

RESULTS

All patients had multiple small bilateral foci of T2 prolongation within the subcortical and deep white matter. The periventricular region and corpus callosum were also involved. In addition to white matter disease, five patients had cortical lesions, three had brain stem involvement, and a single thalamic lesion was detected in one patient. All lesions were less than 1 cm in maximum diameter. In five patients, diffusion-weighted images showed increased signal. Four patients had leptomeningeal enhancement and four had enhancement of parenchymal lesions.

CONCLUSION

The brain MR findings in patients infected with the newly discovered Nipah paramyxovirus are different from those of patients with Japanese encephalitis. In a zoonotic epidemic, this striking difference in the appearance and distribution of lesions is useful in differentiating these diseases. Diffusion-weighted imaging was advantageous in increasing lesion conspicuity.

Molecular detection of TEL-AML1 transcripts as a diagnostic tool and for monitoring of minimal residual disease in B-lineage childhood acute lymphoblastic leukemia

The chromosomal translocation t(12;21) (p12;q22) which results in the TEL-AML1 fusion gene is the most frequent genetic rearrangement in childhood B-lineage acute lymphoblastic leukemia (ALL). The rearrangement in this locus, however, is only rarely observed by routine karyotypic analysis. We established a nested-reverse transcriptase-polymerase chain reaction (nested-RT-PCR) technique for the detection of the TEL-AML1 transcript, and used this to investigate the incidence of the rearrangement, and to characterize the disease present in TEL-AML1-positive B-lineage ALL patients. The TEL-AML1 fusion transcript was detected in nine of fourteen patients. These patients were relatively homogeneous in that they were young and had low presenting leukocyte counts, both features of which are associated with a favorable prognosis. Furthermore, we could detect the TEL-AML1 transcript in the peripheral blood of t(12;21)-positive patients and we used this to assess minimal residual disease (MRD) in patients during chemotherapy. The data demonstrate that nested-RT-PCR is a suitable tool for diagnosing t(12;21)-positive ALL, that these patients constitute a clinically distinct subgroup of ALL patients, and that the method could also be used to monitor MRD in these patients.

Incident cataract after a five-year interval and lifestyle factors: the Beaver Dam eye study

CONTEXT

A population-based study to investigate risk factors for age-related eye disease was begun in 1987 in a representative American community. Incidence of cataract was subsequently evaluated.

SPECIFIC OBJECTIVES

To examine the relationships of cigarette smoking, alcohol, and caffeine intakes to incidence of age-related cataracts five years later.

DESIGN

Observational epidemiologic incidence study of an adult population.

PARTICIPANTS AND INTERVENTION

Adults 43-84 years of age were identified during a census in 1987-1988, and examined at baseline (1988-1990) and after a five-year interval (1993-1995).

MAIN OUTCOME MEASURE

Standardized protocols were used at the baseline and follow-up evaluations for exposures and for objective identification of cataracts.

RESULTS

Cumulative incidence of nuclear cataract in right eyes was about 12%, cortical cataract about 8%, and posterior subcapsular cataract about 3%. In multivariable analyses of the general estimating equations type, there were significant associations between nuclear cataract and: pack-years smoked (odds ratio [OR] 1.05, 95% confidence interval [CI] 1.01, 1.09 per 10 pack-years); and current alcohol intake (OR 1.01, 95% CI 1.00, 1.02 per 10 grams ethanol/week). Cigarette smokers were more likely to have had cataract surgery in the interval between baseline and follow-up examinations.

CONCLUSIONS

Cigarette smoking and alcohol consumption were associated with modestly increased risks of incident nuclear cataract over a five-year interval.

Comparison of the grade of CIN in colposcopically directed biopsies with that in outpatient loop electrosurgical excision procedure (LEEP) specimens--a retrospective review

BACKGROUND

It has been suggested that LEEP should be the standard for the diagnosis of cervical dysplasia, rather than colposcopically directed biopsy as traditionally so, since it is both diagnostic and therapeutic.

PATIENTS

Seventy-eight patients who underwent LEEP at the Gynaecological Cancer Centre, KK Hospital from 1 January 1995 to 31 December 1997 for cervical dysplasia diagnosed by colposcopically directed biopsy were retrospectively reviewed. The mean age of the patients was 40.3 years (SD 8.4), with 78.2% of them with CIN I or CIN II. The mean operating time was 11.8 minutes (SD 4.9) and 53.8% (42/78) were given prophylactic antibiotics, with the only complication being moderate postoperative haemorrhage in 3.8% (3/78). The mean follow-up period was 19.1 months (SD 9.3) with the cure rate being 97.4% (76/78).

RESULTS

Only half of the patients had corresponding histologies on biopsy and LEEP, with 28.2% (22/78) undergraded and 21.8% (17/78) overgraded.

CONCLUSION

Significant discrepancies may be found between the results of colposcopically directed biopsy and loop excision, and LEEP, which is safe and effective may be the choice procedure for the diagnosis of cervical dysplasia.

Correlates of urinary symptom scores in men

OBJECTIVES

This study determined the prevalence of urinary symptoms and their relationship to characteristics of a cohort of men in Beaver Dam, Wis, from 1993 to 1995.

METHODS

A standardized questionnaire concerning urinary symptoms (the American Urological Association Urinary Symptom Questionnaire) was administered.

RESULTS

All outcomes were associated with age and history of enlarged prostate. Urinary frequency (57%) and nocturia (65%) were the most common individual symptoms. Diuretic usage, diabetes, history of cardiovascular disease, and smoking were related to specific symptoms.

CONCLUSIONS

While urinary symptoms are associated with age and history of enlarged prostate, symptoms may also be attributable to other diseases and exposures.

Outbreak of Nipah-virus infection among abattoir workers in Singapore

BACKGROUND

In March 1999, an outbreak of encephalitis and pneumonia occurred in workers at an abattoir in Singapore. We describe the clinical presentation and the results of investigations in these patients.

METHODS

Clinical and laboratory data were collected by systemic review of the case records. Serum and cerebrospinal fluid (CSF) samples were tested for IgM antibodies to Nipah virus with an IgM capture ELISA. Reverse-transcriptase PCR was done on the CSF and tissue samples from one patient who died.

FINDINGS

Eleven patients were confirmed to have acute Nipah-virus infection based on raised IgM in serum. Nipah virus was identified by reverse transcriptase PCR in the CSF and tissue of the patient who died. The patients were all men, with a median age of 44 years. The commonest presenting symptoms were fever, headache, and drowsiness. Eight patients presented with signs of encephalitis (decreased level of consciousness or focal neurological signs). Three patients presented with atypical pneumonia, but one later developed hallucinations and had evidence of encephalitis on CSF examination. Abnormal laboratory findings included a low lymphocyte count (nine patients), low platelet count, low serum sodium, and high aspartate aminostransferase concentration (each observed in five patients). The CSF protein was high in eight patients and white-blood-cell count was high in seven. Chest radiography showed mild interstitial shadowing in eight patients. Magnetic resonance imaging (MRI) showed focal areas of increased signal intensity in the cortical white marker in all eight patients who were scanned. The nine patients with encephalitis received empirical treatment with intravenous aciclovir and eight survived.

INTERPRETATION

Infection with Nipah virus caused an encephalitis illness with characteristic focal areas of increased intensity seen on MRI. Lung involvement was also common, and the disease may present as an atypical pneumonia.

The neurological manifestations of Nipah virus encephalitis, a novel paramyxovirus

A novel Hendra-like paramyxovirus named Nipah virus (NiV) was the cause of an outbreak among workers from one abattoir who had contact with pigs. Two patients had only respiratory symptoms, while 9 patients had encephalitis, 7 of whom are described in this report. Neurological involvement was diverse and multifocal, including aseptic meningitis, diffuse encephalitis, and focal brainstem involvement. Cerebellar signs were relatively common. Magnetic resonance imaging scans of the brain showed scattered lesions. IgM antibodies against Hendra virus (HeV) were present in the serum of all patients. Two patients recovered completely. Five had residual deficits 8 weeks later.