Johan H. Seland

Sunlight exposure, antioxidants, and age-related macular degeneration

OBJECTIVE To examine the association of sunlight exposure and antioxidant level with age-related macular degeneration (AMD). METHODS Four thousand seven hundred fifty-three participants aged 65 years or older in the European Eye Study underwent fundus photography, were interviewed for adult lifetime sunlight exposure, and gave blood for antioxidant analysis. Blue light exposure was estimated by combining meteorologic and questionnaire data. RESULTS Data on sunlight exposure and antioxidants were available in 101 individuals with neovascular AMD, 2182 with early AMD, and 2117 controls. No association was found between blue light exposure and neovascular or early AMD. Significant associations were found between blue light exposure and neovascular AMD in individuals in the quartile of lowest antioxidant level-vitamin C, zeaxanthin, vitamin E, and dietary zinc-with an odds ratio of about 1.4 for 1 standard deviation unit increase in blue light exposure. Higher odds ratios for blue light were observed with combined low antioxidant levels, especially vitamin C, zeaxanthin, and vitamin E (odds ratio, 3.7; 95% confidence interval, 1.6-8.9), which were also associated with early stages of AMD. CONCLUSIONS Although it is not possible to establish causality between sunlight exposure and neovascular AMD, our results suggest that people in the general population should use ocular protection and follow dietary recommendations for the key antioxidant nutrients.

Evidence of association of APOE with age‐related macular degeneration ‐ a pooled analysis of 15 studies

Age‐related macular degeneration (AMD) is the most common cause of incurable visual impairment in high‐income countries. Previous studies report inconsistent associations between AMD and apolipoprotein E (APOE), a lipid transport protein involved in low‐density cholesterol modulation. Potential interaction between APOE and sex, and smoking status has been reported. We present a pooled analysis (n = 21,160) demonstrating associations between late AMD and APOε4 (odds ratio [OR] = 0.72 per haplotype; confidence interval [CI]: 0.65–0.74; P = 4.41×10−11) and APOε2 (OR = 1.83 for homozygote carriers; CI: 1.04–3.23; P = 0.04), following adjustment for age group and sex within each study and smoking status. No evidence of interaction between APOE and sex or smoking was found. Ever smokers had significant increased risk relative to never smokers for both neovascular (OR = 1.54; CI: 1.38–1.72; P = 2.8×10−15) and atrophic (OR = 1.38; CI: 1.18–1.61; P = 3.37×10−5) AMD but not early AMD (OR = 0.94; CI: 0.86–1.03; P = 0.16), implicating smoking as a major contributing factor to disease progression from early signs to the visually disabling late forms. Extended haplotype analysis incorporating rs405509 did not identify additional risks beyond ε2 and ε4 haplotypes. Our expanded analysis substantially improves our understanding of the association between the APOE locus and AMD. It further provides evidence supporting the role of cholesterol modulation, and low‐density cholesterol specifically, in AMD disease etiology. 32:1407–1416, 2011. ©2011 Wiley Periodicals, Inc.

DNA-based eye colour prediction across Europe with the IrisPlex system.

The ability to predict Externally Visible Characteristics (EVCs) from DNA, also referred to as Forensic DNA Phenotyping (FDP), is an exciting new chapter in forensic genetics holding great promise for tracing unknown individuals who are unidentifiable via standard forensic short tandem repeat (STR) profiling. For the purpose of DNA-based eye colour prediction, we previously developed the IrisPlex system consisting of a multiplex genotyping assay and a prediction model based on genotype and phenotype data from 3804 Dutch Europeans. Recently, we performed a forensic developmental validation study of the highly sensitive IrisPlex assay, which currently represents the only validated tool available for DNA-based prediction of eye colour in forensic applications. In the present study, we validate the IrisPlex prediction model by extending our initially described model towards genotype and phenotype data from multiple European populations. We performed IrisPlex analysis on 3840 individuals from seven sites across Europe as part of the European Eye (EUREYE) study for which DNA and high-resolution eye images were available. The accuracy rate of correctly predicting an individuals eye colour as being blue or brown, above the empirically established probability threshold of 0.7, was on average 94% across all seven European populations, ranging from 91% to 98%, despite the large variation in eye colour frequencies between the populations. The overall prediction accuracies expressed by the area under the receiver characteristic operating curves (AUC) were 0.96 for blue and 0.96 for brown eyes, which is considerably higher than those established before. The IrisPlex prediction model parameters generated from this multi-population European dataset, and thus its prediction capabilities, were highly comparable to those previously established. Therefore, the increased information regarding eye colour phenotype and genotype distributions across Europe, and the systems ability to provide eye colour predictions across Europe accurately, both highlight additional evidence for the utility of the IrisPlex system in forensic casework.

Variations in Apolipoprotein E Frequency With Age in a Pooled Analysis of a Large Group of Older People

Variation in the apolipoprotein E gene (APOE) has been reported to be associated with longevity in humans. The authors assessed the allelic distribution of APOE isoforms ε2, ε3, and ε4 among 10,623 participants from 15 case-control and cohort studies of age-related macular degeneration (AMD) in populations of European ancestry (study dates ranged from 1990 to 2009). The authors included only the 10,623 control subjects from these studies who were classified as having no evidence of AMD, since variation within the APOE gene has previously been associated with AMD. In an analysis stratified by study center, gender, and smoking status, there was a decreasing frequency of the APOE ε4 isoform with increasing age (χ(2) for trend = 14.9 (1 df); P = 0.0001), with a concomitant increase in the ε3 isoform (χ(2) for trend = 11.3 (1 df); P = 0.001). The association with age was strongest in ε4 homozygotes; the frequency of ε4 homozygosity decreased from 2.7% for participants aged 60 years or less to 0.8% for those over age 85 years, while the proportion of participants with the ε3/ε4 genotype decreased from 26.8% to 17.5% across the same age range. Gender had no significant effect on the isoform frequencies. This study provides strong support for an association of the APOE gene with human longevity.

Methods for a population-based study of the prevalence of and risk factors for age-related maculopathy and macular degeneration in elderly european populations: the EUREYE study.

PURPOSE The aims of the EUREYE study are to evaluate the prevalence of age-related maculopathy (ARM), including macular degeneration (AMD), in elderly European populations, to investigate risk factors for ARM and AMD, especially solar radiation and diet, and to measure the impact of these conditions on vision-related quality of life. METHODS A population-based cross-sectional study with retrospective and current exposure measurements. Risk factor assessment is via questionnaires (for lifestyle factors such as smoking and alcohol, dietary risk factors, outdoor exposure) and blood analysis. Participants are people aged 65 and over. The study is carried out in 7 centres with locations spanning north to south Europe. The main outcome measure is grading of fundus photographs (for stage and type of ARM, using the International ARM Epidemiological Study Group grading system).

Visual impairment and quality of life in the older European population, the EUREYE study

Purpose:  To determine the prevalence of visual impairment (VI) in populations 65 year or older from six European countries and describe the association with vision‐related quality of life. VI was defined according to WHO as best corrected visual acuity <6/18/log MAR >0,48 (World Health Organization (1992): International Statistical Classification of Diseases and Related Health Problems, 10th revised ed. Vol 1. Geneva).

ULTRASTRUCTURAL CHANGES IN THE NORMAL HUMAN LENS CAPSULE FROM BIRTH TO OLD AGE

Ten normal lens capsules have been studied by means of transmission electron microscopy. A surface layer containing fibres (lamina zonularis) is present on the whole of the ant. capsule at birth. This layer disappears from the ant. pole in the first or second decade of life. A laminar architecture of the proper capsule has been confirmed and age dependant loss of lamination has been observed. The appearance of electron dense formed elements in the capsule seems to be a specific ageing phenomenon and three types of elements are described. “Hassall‐Henle”‐like bodies have been demonstrated in the peripheral part of the capsule.

Associations between aspirin use and aging macula disorder: The European eye study

OBJECTIVE To study associations between aspirin use and early and late aging macula disorder (AMD). DESIGN Population-based cross-sectional European Eye Study in 7 centers from northern to southern Europe. PARTICIPANTS In total, 4691 participants 65 years of age and older, collected by random sampling. METHODS Aspirin intake and possible confounders for AMD were ascertained by a structured questionnaire. Ophthalmic and basic systemic measurements were performed in a standardized way. The study classified AMD according to the modified International Classification System on digitized fundus images at 1 grading center. Nonfasting blood samples were analyzed in a single laboratory. Associations were analyzed by logistic regression. MAIN OUTCOME MEASURES Odds ratios (ORs) for AMD in aspirin users. RESULTS Early AMD was present in 36.4% of the participants and late AMD was present in 3.3% of participants. Monthly aspirin use was reported by 1931 (41.2%), at least once weekly by 7%, and daily use by 17.3%. For daily aspirin users, the ORs, adjusted for potential confounders, showed a steady increase with increasing severity of AMD grades. These were: grade 1, 1.26 (95% confidence interval [CI], 1.08-1.46; P<0.001); grade 2, 1.42 (95% CI, 1.18-1.70), and wet late AMD, 2.22 (95% CI, 1.61-3.05). CONCLUSIONS Frequent aspirin use was associated with early AMD and wet late AMD, and the ORs rose with increasing frequency of consumption. This interesting observation warrants further evaluation of the associations between aspirin use and AMD. FINANCIAL DISCLOSURE(S) The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Association of diabetes with age-related macular degeneration in the EUREYE study

Objective: To examine the association between self-reported diabetes history and early or late age-related macular degeneration (AMD) in the European population. Methods: Participants aged 65 years and over in the cross-sectional population-based EUREYE study underwent an eye examination including digital retinal photography. The images were graded at a single centre. A structured questionnaire was administered by trained field workers for putative risk factors for AMD including history of diabetes mellitus. Logistic regression models were used to examine the association between diabetes and stages of AMD, taking account of potential demographic, behavioural, dietary and medical (history of cardiovascular disease) confounders. Main outcome measures: Photographic images were graded according to the modified International Classification System for AMD and stratified into five exclusive stages from no signs of AMD (AMD stage 0), early AMD (Stages 1–3) and late AMD (Stage 4). Late AMD was subdivided in neovascular AMD (NV-AMD) or geographic atrophy (GA). Results: Data on diabetes history and potential confounders were available in 2117 control subjects without AMD, 2182 with early AMD, 49 with GA and 101 with NV-AMD. Of all participants, 13.1% reported a history of diabetes. After adjusting for potential confounders, subjects with neovascular AMD compared with controls had increased odds for diabetes (odds ratio 1.81; 95% confidence interval, 1.10 to 2.98, p = 0.02). Subjects with AMD grades 1 to 3 or GA had no increased odds for diabetes compared with those without AMD. Conclusions: In the EUREYE study, after multiple adjustments, positive association of diabetes mellitus with neovascular AMD was found. The hypothesis that diabetes is associated with neovascular AMD but not with geographic atrophy may suggest a different pathogenesis of the two advanced forms of the disease and needs to be further evaluated.

THE ULTRASTRUCTURAL CHANGES IN THE EXFOLIATION SYNDROME

Abstract. Exfoliation fibrils have a characteristic ultramicroscopi appearance. They are 20–30 nm thick with 10 nm subunits and may be 800 or 900 nm long. They sometimes have a characteristic banding periodicity of about 50 nm. The fibrils have been located in the lens capsule, zonular threads, iris, ciliary body and trabecular meshwork. Extraocular locations have also been found in conjunctival vessels and retroorbital tissue.