Chelsea E. Myers

Markers of Inflammation, Oxidative Stress, and Endothelial Dysfunction and the 20-Year Cumulative Incidence of Early Age-Related Macular Degeneration: The Beaver Dam Eye Study

IMPORTANCE Modifying levels of factors associated with age-related macular degeneration (AMD) may decrease the risk for visual impairment in older persons. OBJECTIVE To examine the relationships of markers of inflammation, oxidative stress, and endothelial dysfunction to the 20-year cumulative incidence of early AMD. DESIGN, SETTING, AND PARTICIPANTS This longitudinal population-based cohort study involved a random sample of 975 persons in the Beaver Dam Eye Study without signs of AMD who participated in the baseline examination in 1988-1990 and up to 4 follow-up examinations in 1993-1995, 1998-2000, 2003-2005, and 2008-2010. EXPOSURES Serum markers of inflammation (high-sensitivity C-reactive protein, tumor necrosis factor-α receptor 2, interleukin-6, and white blood cell count), oxidative stress (8-isoprostane and total carbonyl content), and endothelial dysfunction (soluble vascular cell adhesion molecule-1 and soluble intercellular adhesion molecule-1) were measured. Interactions with complement factor H (rs1061170), age-related maculopathy susceptibility 2 (rs10490924), complement component 3 (rs2230199), and complement component 2/complement factor B (rs4151667) were examined using multiplicative models. Age-related macular degeneration was assessed from fundus photographs. MAIN OUTCOMES AND MEASURES Early AMD defined by the presence of any size drusen and the presence of pigmentary abnormalities or by the presence of large-sized drusen (≥125-μm diameter) in the absence of late AMD. RESULTS The 20-year cumulative incidence of early AMD was 23.0%. Adjusting for age, sex, and other risk factors, high-sensitivity C-reactive protein (odds ratio comparing fourth with first quartile, 2.18; P = .005), tumor necrosis factor-α receptor 2 (odds ratio, 1.78; P = .04), and interleukin-6 (odds ratio, 1.78; P = .03) were associated with the incidence of early AMD. Increased incidence of early AMD was associated with soluble vascular cell adhesion molecule-1 (odds ratio per SD on the logarithmic scale, 1.21; P = .04). CONCLUSIONS AND RELEVANCE We found modest evidence of relationships of serum high-sensitivity C-reactive protein, tumor necrosis factor-α receptor 2, interleukin-6, and soluble vascular cell adhesion molecule-1 to the 20-year cumulative incidence of early AMD independent of age, smoking status, and other factors. It is not known whether these associations represent a cause and effect relationship or whether other unknown confounders accounted for the findings. Even if inflammatory processes are a cause of early AMD, it is not known whether interventions that reduce systemic inflammatory processes will reduce the incidence of early AMD.

Changes in Retinal Vessel Diameter and Incidence and Progression of Diabetic Retinopathy

OBJECTIVE To describe the relationship of change in retinal vessel diameters to the subsequent 6-year incidence and progression of diabetic retinopathy (DR) and incidence of proliferative diabetic retinopathy (PDR) and macular edema (ME) in persons with diabetes mellitus. DESIGN A total of 1098 persons with diabetes who had DR graded from fundus photographs and had computer-assisted measurements of the central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent(CRVE) participated in examinations in 1980-1982, 1984-1986, and 1990-1992. RESULTS During the first 4-year period, the mean change in CRAE and CRVE was −0.37 and 2.54 μm, respectively.The 6-year incidence and progression of DR and the incidence of PDR and ME from 1984-1986 to 1990-1992 were 56%, 39%, 15%, and 11%, respectively. In multivariate analyses, while controlling for duration, diabetes type, and other factors, an increase of 10 μm in CRVE from 1980-1982 to 1984-1986 was associated with increases in the 6-year incidence of DR (odds ratio [OR],1.26; 95% CI, 1.10-1.43), progression of DR (OR, 1.21;95% CI, 1.12-1.30), incidence of PDR (OR, 1.19; 95%CI, 1.07-1.32), and incidence of ME (OR, 1.16; 95% CI,1.03-1.31). No interactions of these associations by diabetes type were found (data not shown). Change in CRAE was unrelated to the incidence or progression of DR (data not shown). CONCLUSIONS Independent of DR severity level, glycemic control, and other factors, widening of the retinal venular but not arteriolar diameter was associated with subsequent incidence and progression of DR. The CRVE may provide additional information regarding the risk of incidence and progression of DR beyond traditional risk factors.

The prevalence of macular telangiectasia type 2 in the Beaver Dam eye study.

PURPOSE To examine the prevalence of macular telangiectasia type 2 and lesions characterizing it. DESIGN Population-based cohort study. METHODS setting: City and township of Beaver Dam, 1988-1990. study population: A total of 4790 people 43-86 years of age. observation procedure(s): Grading from stereoscopic fundus photographs to measure macular telangiectasia type 2. main outcome measure: Prevalent macular telangiectasia type 2. RESULTS Macular telangiectasia type 2 was present at baseline in 0.1% of the population (95% confidence interval [CI] 0.09, 0.1). The frequencies of loss of retinal transparency, crystals in the inner retinal layers, blunted retinal vessels, localized intraretinal pigment migration in the juxtafoveolar region, and presence of yellow deposits and lamellar holes in the foveal area in those without macular telangiectasia type 2 varied from 0.06% for retinal telangiectatic vessels to 1.2% for lamellar holes. Smoking was associated with pigment clumping (odds ratio [OR] per pack year 1.02; 95% CI 1.00, 1.03; P = .02), retinal pigment epithelial (RPE) depigmentation (OR 1.02 per pack year; 95%CI 1.00, 1.04; P = .02), loss of transparency (OR 1.02 per pack year; 95% CI 1.00, 1.03; P = .008), and the presence of a yellow spot in the fovea (OR 2.24 current vs past or never smoker; 95% CI 1.29, 3.89; P = .004), but not with presence of macular telangiectasia type 2 (OR 2.72; 95% CI 0.45, 16.28; P = .27). CONCLUSIONS The prevalence of macular telangiectasia type 2 (0.1%) is higher than previously thought. These data are useful in estimating the burden of this condition in the population. The role of smoking in the development of macular telangiectasia type 2 requires further study.

Prediction of age-related macular degeneration in the general population: the Three Continent AMD Consortium.

PURPOSE Prediction models for age-related macular degeneration (AMD) based on case-control studies have a tendency to overestimate risks. The aim of this study is to develop a prediction model for late AMD based on data from population-based studies. DESIGN Three population-based studies: the Rotterdam Study (RS), the Beaver Dam Eye Study (BDES), and the Blue Mountains Eye Study (BMES) from the Three Continent AMD Consortium (3CC). PARTICIPANTS People (n = 10,106) with gradable fundus photographs, genotype data, and follow-up data without late AMD at baseline. METHODS Features of AMD were graded on fundus photographs using the 3CC AMD severity scale. Associations with known genetic and environmental AMD risk factors were tested using Cox proportional hazard analysis. In the RS, the prediction of AMD was estimated for multivariate models by area under receiver operating characteristic curves (AUCs). The best model was validated in the BDES and BMES, and associations of variables were re-estimated in the pooled data set. Beta coefficients were used to construct a risk score, and risk of incident late AMD was calculated using Cox proportional hazard analysis. Cumulative incident risks were estimated using Kaplan-Meier product-limit analysis. MAIN OUTCOME MEASURES Incident late AMD determined per visit during a median follow-up period of 11.1 years with a total of 4 to 5 visits. RESULTS Overall, 363 participants developed incident late AMD, 3378 participants developed early AMD, and 6365 participants remained free of any AMD. The highest AUC was achieved with a model including age, sex, 26 single nucleotide polymorphisms in AMD risk genes, smoking, body mass index, and baseline AMD phenotype. The AUC of this model was 0.88 in the RS, 0.85 in the BDES and BMES at validation, and 0.87 in the pooled analysis. Individuals with low-risk scores had a hazard ratio (HR) of 0.02 (95% confidence interval [CI], 0.01-0.04) to develop late AMD, and individuals with high-risk scores had an HR of 22.0 (95% CI, 15.2-31.8). Cumulative risk of incident late AMD ranged from virtually 0 to more than 65% for those with the highest risk scores. CONCLUSIONS Our prediction model is robust and distinguishes well between those who will develop late AMD and those who will not. Estimated risks were lower in these population-based studies than in previous case-control studies.

Genetic Susceptibility, Dietary Antioxidants, and Long-Term Incidence of Age-Related Macular Degeneration in Two Populations

OBJECTIVE To examine effect modification between genetic susceptibility to age-related macular degeneration (AMD) and dietary antioxidant or fish consumption on AMD risk. DESIGN Pooled data analysis of population-based cohorts. PARTICIPANTS Participants from the Blue Mountains Eye Study (BMES) and Rotterdam Study (RS). METHODS Dietary intakes of antioxidants (lutein/zeaxanthin [LZ], β-carotene, and vitamin C), long-chain omega-3 polyunsaturated fatty acids, and zinc were estimated from food frequency questionnaires. The AMD genetic risk was classified according to the number of risk alleles of CFH (rs1061170) or ARMS2 (rs10490924) as low (no or 1 risk allele) or high (≥ 2 risk alleles). Interactions between dietary intake and genetic risk levels were assessed. Associations between dietary intake and AMD risk were assessed comparing the highest with the 2 lower intake tertiles by genetic risk subgroups using discrete logistic regression, conducted in each study separately and then using pooled data. Participants without AMD lesions at any visit were controls. We adjusted for age and sex in analyses of each cohort sample and for smoking status and study site in pooled-data analyses. MAIN OUTCOME MEASURES All 15-year incident late AMD cases were confirmed by chief investigators of the Beaver Dam Eye Study, BMES, and RS. Intergrader reproducibility was assessed in an early AMD subsample, with 86.4% agreement between BMES and RS graders, allowing for a 1-step difference on a 5-step AMD severity scale. RESULTS In pooled data analyses, we found significant interaction between AMD genetic risk status and LZ intake (P=0.0009) but nonsignificant interactions between genetic risk status and weekly fish consumption (P=0.05) for risk of any AMD. Among participants with high genetic risk, the highest intake tertile of LZ was associated with a >20% reduced risk of early AMD, and weekly consumption of fish was associated with a 40% reduced risk of late AMD. No similar association was evident among participants with low genetic risk. No interaction was detected between β-carotene or vitamin C and genetic risk status. CONCLUSIONS Protection against AMD from greater LZ and fish consumption in persons with high genetic risk based on 2 major AMD genes raises the possibility of personalized preventive interventions.

Lipids, Lipid Genes, and Incident Age-Related Macular Degeneration: The Three Continent Age-Related Macular Degeneration Consortium

PURPOSE To describe associations of serum lipid levels and lipid pathway genes to the incidence of age-related macular degeneration (AMD). DESIGN Meta-analysis. METHODS setting: Three population-based cohorts. population: A total of 6950 participants from the Beaver Dam Eye Study (BDES), Blue Mountains Eye Study (BMES), and Rotterdam Study (RS). observation procedures: Participants were followed over 20 years and examined at 5-year intervals. Hazard ratios associated with lipid levels per standard deviation above the mean or associated with each additional risk allele for each lipid pathway gene were calculated using random-effects inverse-weighted meta-analysis models, adjusting for known AMD risk factors. main outcome measures: Incidence of AMD. RESULTS The average 5-year incidences of early AMD were 8.1%, 15.1%, and 13.0% in the BDES, BMES, and RS, respectively. Substantial heterogeneity in the effect of cholesterol and lipid pathway genes on the incidence and progression of AMD was evident when the data from the 3 studies were combined in meta-analysis. After correction for multiple comparisons, we did not find a statistically significant association between any of the cholesterol measures, statin use, or serum lipid genes and any of the AMD outcomes in the meta-analysis. CONCLUSION In a meta-analysis, there were no associations of cholesterol measures, history of statin use, or lipid pathway genes to the incidence and progression of AMD. These findings add to inconsistencies in earlier reports from our studies and others showing weak associations, no associations, or inverse associations of high-density lipoprotein cholesterol and total cholesterol with AMD.

Risk Alleles in CFH and ARMS2 and the Long-term Natural History of Age-Related Macular Degeneration: The Beaver Dam Eye Study

OBJECTIVE To describe the relationships of risk alleles in complement factor H (CFH, rs1061170) and age-related maculopathy susceptibility 2 (ARMS2, rs10490924) to the incidence and progression of age-related macular degeneration (AMD) during a 20-year period. METHODS There were 4282 persons aged 43 to 86 years at the baseline examination in 1988-1990 enrolled in a population-based cohort study who participated in at least 1 examination spaced 5 years apart during a 20-year period and had gradable fundus photographs for AMD and genotype information on CFH and ARMS2. Low, intermediate, and high genetic risk for AMD was defined by the presence of 0 to 1, 2, or 3 to 4 risk alleles for CFH and ARMS2, respectively. Multistate models were used to estimate the progression of AMD throughout the entire age range. RESULTS There were 2820 (66%), 1129 (26%), and 333 persons (8%) with low, intermediate, and high genetic risk for AMD, respectively. The 5-year incidences of early and late AMD were 9.1% and 1.6%, respectively, and increased with age but did not differ significantly by sex. Using the multistate model, of persons aged 45 years with no AMD in the low, intermediate, and high AMD genetic risk groups, 33.0%, 39.9%, and 46.5%, respectively, were estimated to develop early AMD, and 1.4%, 5.2%, and 15.3% were estimated to develop late AMD by age 80 years. CONCLUSIONS These population-based data provide estimates of the long-term risk of the incidence and progression of AMD and its lesions by age and genetic risk alleles for CFH and ARMS2. They also show that when early AMD is present, knowing the phenotype contributes more to risk assessment than knowing the genetic risk based on these 2 AMD genes.

The Epidemiology of Vitreoretinal Interface Abnormalities as Detected by Spectral-Domain Optical Coherence Tomography: The Beaver Dam Eye Study

PURPOSE To describe the prevalence and interrelationships of epiretinal membranes (ERMs), vitreomacular traction (VMT), macular cysts, paravascular cysts (PVCs), lamellar macular holes (LMHs), full-thickness macular holes (FTMHs), and visual impairment in a population-based study of older adults. DESIGN Cross-sectional study. PARTICIPANTS There were 1913 participants aged 63 to 102 years at the 20-year Beaver Dam Eye Study follow-up examination in 2008-2010, of whom 1540 (2980 eyes) had gradable spectral-domain optical coherence tomography (SD OCT) scans of the macula in at least 1 eye. METHODS The presence of ERMs and other retinal lesions was determined by standardized grading of macular SD OCT scans and photographs of 3 standard fields. MAIN OUTCOME MEASURES Epiretinal membranes, VMT, macular cysts, PVCs, LMHs, FTMHs, and visual impairment. RESULTS By using SD OCT, the prevalence of ERMs (34.1%), VMT (1.6%), macular cysts (5.6%), PVCs (20.0%), LMHs (3.6%), and FTMHs (0.4%) was estimated. The prevalence of macular cysts (P < 0.001), ERMs (P < 0.001), and VMT (P = 0.005) increased with age; the prevalence of PVCs (P = 0.05) decreased with age; and the prevalence of LMHs was not associated with age (P = 0.70). The prevalence of macular cysts, LMHs, and ERMs was higher in eyes with a history of cataract surgery. Macular cysts and ERMs were more common in eyes with retinal diseases, such as proliferative diabetic retinopathy, retinal vein occlusion, and retinal detachment, than in eyes without these conditions. Macular cysts, ERMs, and FTMHs were associated with visual impairment. While adjusting for age and sex, macular cysts (odds ratio [OR], 3.96; P < 0.0001), PVCs (OR, 1.45, P = 0.007), LMHs (OR, 10.62; P < 0.001), VMT (OR, 2.72, P = 0.01), and visual impairment (OR, 3.23; P < 0.001) were more frequent in eyes with ERMs compared with eyes without ERMs. CONCLUSIONS Epiretinal membranes are associated with macular cysts, PVCs, LMHs, VMT, and visual impairment. Further follow-up will allow better understanding of the natural history of ERMs and VMT and their relationships to the development of macular cysts and LMHs in the aging population.

Supplementation with three different macular carotenoid formulations in patients with early age-related macular degeneration.

Purpose: To investigate the impact of three different macular carotenoid formulations on macular pigment optical density and visual performance in subjects with early age-related macular degeneration. Methods: Fifty-two subjects were supplemented and followed for 12 months, 17 of them were in intervention Group 1 (20 mg/day lutein and 2 mg/day zeaxanthin); 21 in Group 2 (10 mg/day meso-zeaxanthin, 10 mg/day lutein, and 2 mg/day zeaxanthin); and 14 in Group 3 (17 mg/day meso-zeaxanthin, 3 mg/day lutein, and 2 mg/day zeaxanthin). The macular pigment optical density was measured using customized heterochromatic flicker photometry, and visual function was assessed using corrected distance visual acuity and by letter contrast sensitivity. Results: A statistically significant increase in the macular pigment optical density was observed at all measured eccentricities in Group 2 (P ⩽ 0.005) and in Group 3 (P < 0.05, for all), but only at 1.75° in Group 1 (P = 0.018). Statistically significant (P < 0.05) improvements in letter contrast sensitivity were seen at all spatial frequencies (except 1.2 cycles per degree) in Group 3, and at low spatial frequencies in Groups 1 and 2. Conclusion: Augmentation of the macular pigment optical density across its spatial profile and enhancements in contrast sensitivity were best achieved after supplementation with a formulation containing high doses of meso-zeaxanthin in combination with lutein and zeaxanthin.

Harmonizing the classification of age-related macular degeneration in the three-continent AMD consortium

Abstract Purpose: To describe methods to harmonize the classification of age-related macular degeneration (AMD) phenotypes across four population-based cohort studies: the Beaver Dam Eye Study (BDES), the Blue Mountains Eye Study (BMES), the Los Angeles Latino Eye Study (LALES), and the Rotterdam Study (RS). Methods: AMD grading protocols, definitions of categories, and grading forms from each study were compared to determine whether there were systematic differences in AMD severity definitions and lesion categorization among the three grading centers. Each center graded the same set of 60 images using their respective systems to determine presence and severity of AMD lesions. A common 5-step AMD severity scale and definitions of lesion measurement cutpoints and early and late AMD were developed from this exercise. Results: Applying this severity scale changed the age-sex adjusted prevalence of early AMD from 18.7% to 20.3% in BDES, from 4.7% to 14.4% in BMES, from 14.1% to 15.8% in LALES, and from 7.5% to 17.1% in RS. Age-sex adjusted prevalences of late AMD remained unchanged. Comparison of each center’s grades of the 60 images converted to the consortium scale showed that exact agreement of AMD severity among centers varied from 61.0–81.4%, and one-step agreement varied from 84.7–98.3%. Conclusion: Harmonization of AMD classification reduced categorical differences in phenotypic definitions across the studies, resulted in a new 5-step AMD severity scale, and enhanced similarity of AMD prevalence among the four cohorts. Despite harmonization it may still be difficult to remove systematic differences in grading, if present.