Systemic Evidence for Mitochondrial Dysfunction in Age-Related Macular Degeneration as Revealed by mtDNA Copy Number Measurements in Peripheral Blood.

Mitochondrial dysfunction is a common occurrence in the aging process and is observed in diseases such as age-related macular degeneration (AMD). Increased levels of reactive oxygen species lead to damaged mitochondrial DNA (mtDNA), resulting in dysfunctional mitochondria, and, consequently, mtDNA causes further harm in the retinal tissue. However, it is unclear whether the effects are locally restricted to the high-energy-demanding retinal pigment epithelium or are also systematically present. Therefore, we measured mtDNA copy number (mtDNA-CN) in peripheral blood using a qPCR approach with plasmid normalization in elderly participants with and without AMD from the AugUR study (n = 2262). We found significantly lower mtDNA-CN in the blood of participants with early (n = 453) and late (n = 170) AMD compared to AMD-free participants (n = 1630). In regression analyses, we found lower mtDNA-CN to be associated with late AMD when compared with AMD-free participants. Each reduction of mtDNA-CN by one standard deviation increased the risk for late AMD by 24%. This association was most pronounced in geographic atrophy (OR = 1.76, 95% CI 1.19-2.60, p = 0.004), which has limited treatment options. These findings provide new insights into the relationship between mtDNA-CN in blood and AMD, suggesting that it may serve as a more accessible biomarker than mtDNA-CN in the retina.

[Awareness for glaucoma in the general population]. / Bewusstsein für eine Glaukomerkrankung in der Bevölkerung.

BACKGROUND: Glaucoma is not a rare entity but because very few symptoms occur and visual field defects are frequently first recognized at a late stage, a large proportion of glaucoma diseases remain undetected. The aim of this study was to identify the proportion of undiagnosed glaucoma in German population-based cohort studies and to contextualize them in the context of the literature. MATERIAL AND METHODS: The prevalence of glaucoma in the Gutenberg Health Study (GHS) and the age-related investigations on health of the University of Regensburg (AugUR) was evaluated based on visual field examinations and optic disc color photography according to the ISGEO criteria. Furthermore, the self-reported glaucoma diagnoses were collected and the proportion of undiagnosed glaucoma was determined. RESULTS: The proportion of undiagnosed glaucoma was 55% in the GHS, and 53% in the AugUR study. The results correlate with results from previous studies from other countries in which the proportion of unrecognized glaucoma ranged from 33% to 78%. In the GHS and the AugUR study the proportion of undiagnosed glaucoma was higher in younger age groups and in women. DISCUSSION: Roughly every second case of glaucoma is undetected. As the symptoms are often nonspecific or take a long time to appear, there is a risk of advanced glaucomatous visual field defects or blindness due to a lack of glaucoma awareness. Studies have shown that a systematic screening can halve this risk.

Baseline characteristics and progression of neovascular age-related macular degeneration in patients receiving over 60 intravitreal injections of anti-vascular endothelial growth factor.

Objective: Age-related macular degeneration (AMD) is the leading cause of vision loss in older populations of industrialized countries. Antibody-based therapy inhibiting the vascular endothelial growth factor (VEGF) has been very successful in the treatment of the neovascular form of AMD. This retrospective clinical study investigates the baseline characteristics and progression of neovascular age-related macular degeneration (nAMD) in patients who received over 60 anti-VEGF intravitreal injections. Methods: Retrospective analysis of 6812 eyes of 5678 patients undergoing anti-VEGF treatment at our clinic between November 2006 and December 2017 yielded 12 eyes of 12 patients who had received more than 60 intravitreal injections into one eye. We re-evaluated the baseline characteristics of visual acuity, intraocular pressure, optical coherence tomography, fluorescein angiography, as well as autofluorescence and analyzed the documented disease progress as monitored in our daily clinical practice. Data on the fellow eye were also analyzed. Results: Each of our 12 patients had the injected anti-VEGF agent (bevacizumab, ranibizumab, or aflibercept) changed at least once during treatment. After initial improvement, visual acuity decreased in most patients over time. The 2 patients with the best visual acuity at the beginning also showed the best visual acuity at the end of the study. No significant change was observed in the intraocular pressure. Conclusions: After the initial improvement, visual acuity decreased over time. Good visual acuity at the beginning of the study increased the chances of maintaining the same level throughout the treatment. Intravitreal treatment did not affect intraocular pressure. Abbreviations: AMD = age-related macular degeneration, nAMD = neovascular age-related macular degeneration, VEGF = vascular endothelial growth factor, OCT = optical coherence tomography, VA = visual acuity, PDT = photodynamic therapy.

Genetic Risk Score Analysis Supports a Joint View of Two Classification Systems for Age-Related Macular Degeneration.

Purpose: The purpose of this study was to evaluate the utility of combining the Clinical Classification (CC) and the Three Continent age-related macular degeneration (AMD) Consortium Severity Scale (3CACSS) for classification of AMD. Methods: In two independent cross-sectional datasets of our population-based AugUR study (Altersbezogene Untersuchungen zur Gesundheit der Universität Regensburg), we graded AMD via color fundus images applying two established classification systems (CC and 3CACSS). We calculated the genetic risk score (GRS) across 50 previously identified variants for late AMD, its association via logistic regression, and area under the curve (AUC) for each AMD stage. Results: We analyzed 2188 persons aged 70 to 95 years. When comparing the two classification systems, we found a distinct pattern: CC "age-related changes" and CC "early AMD" distinguished individuals with 3CACSS "no AMD"; 3CACSS "mild/moderate/severe early AMD" stages, and distinguished CC "intermediate AMD". This suggested a 7-step scale combining the 2 systems: (i) "no AMD", (ii) "age-related changes", (iii) "very early AMD", (i.e. CC "early"), (iv) "mild early AMD", (v) "moderate early AMD", (vi) "severe early AMD", and (vii) "late AMD". GRS association and diagnostic accuracy increased stepwise by increased AMD severity in the 7-step scale and by increased restriction of controls (e.g. for CC "no AMD without age-related changes": AUC = 55.1%, 95% confidence interval [CI] = 51.6, 58.6, AUC = 62.3%, 95% CI = 59.1, 65.6, AUC = 63.8%, 95% CI = 59.3, 68.3, AUC = 78.1%, 95% CI = 73.6, 82.5, AUC = 82.2%, 95% CI = 78.4, 86.0, and AUC = 79.2%, 95% CI = 75.4, 83.0). A stepwise increase was also observed by increased drusen size and area. Conclusions: The utility of a 7-step scale is supported by our clinical and GRS data. This harmonization and full data integration provides an immediate simplification over using either CC or 3CACSS and helps to sharpen the control group.

Age-Related Macular Degeneration in an Ageing Society - Current Epidemiological Research. / Altersbedingte Makuladegeneration in einer alternden Gesellschaft ­ aktuelle epidemiologische Forschungsansätze und Erkenntnisse.

Epidemiological studies on age-related macular degeneration (AMD) provide crucial data on the frequency of early and late forms as well as associated risk factors. The increasing number of population-based cross-sectional and longitudinal cohort studies in Germany and Europe with published data is making prevalence and incidence estimators for AMD more robust, although they show mostly method-related fluctuations. This review article brings together the latest published epidemiological measures for AMD from Germany and Central as well as Western Europe. Based on this data and population figures for Germany and Europe, prevalence is projected, and future trends are forecasted. The epidemiological evidence for AMD-associated risk factors is also improving, especially through meta-analyses within large consortia with correspondingly high case numbers. This review article summarizes the latest findings and resulting recommendations for prevention approaches. Additionally, it discusses treatment options and future challenges.

Polygenic scores for estimated glomerular filtration rate in a population of general adults and elderly - comparative results from the KORA and AugUR study.

BACKGROUND: Polygenic scores (PGSs) combining genetic variants found to be associated with creatinine-based estimated glomerular filtration rate (eGFRcrea) have been applied in various study populations with different age ranges. This has shown that PGS explain less eGFRcrea variance in the elderly. Our aim was to understand how differences in eGFR variance and the percentage explained by PGS varies between population of general adults and elderly. RESULTS: We derived a PGS for cystatin-based eGFR (eGFRcys) from published genome-wide association studies. We used the 634 variants known for eGFRcrea and the 204 variants identified for eGFRcys to calculate the PGS in two comparable studies capturing a general adult and an elderly population, KORA S4 (n = 2,900; age 24-69 years) and AugUR (n = 2,272, age ≥ 70 years). To identify potential factors determining age-dependent differences on the PGS-explained variance, we evaluated the PGS variance, the eGFR variance, and the beta estimates of PGS association on eGFR. Specifically, we compared frequencies of eGFR-lowering alleles between general adult and elderly individuals and analyzed the influence of comorbidities and medication intake. The PGS for eGFRcrea explained almost twice as much (R2 = 9.6%) of age-/sex adjusted eGFR variance in the general adults compared to the elderly (4.6%). This difference was less pronounced for the PGS for eGFRcys (4.7% or 3.6%, respectively). The beta-estimate of the PGS on eGFRcrea was higher in the general adults compared to the elderly, but similar for the PGS on eGFRcys. The eGFR variance in the elderly was reduced by accounting for comorbidities and medication intake, but this did not explain the difference in R2-values. Allele frequencies between general adult and elderly individuals showed no significant differences except for one variant near APOE (rs429358). We found no enrichment of eGFR-protective alleles in the elderly compared to general adults. CONCLUSIONS: We concluded that the difference in explained variance by PGS was due to the higher age- and sex-adjusted eGFR variance in the elderly and, for eGFRcrea, also by a lower PGS association beta-estimate. Our results provide little evidence for survival or selection bias.

Cardiovascular Risk Factor Control in 70- to 95-Year-Old Individuals: Cross-Sectional Results from the Population-Based AugUR Study.

Cardiovascular risk factors such as high glucose, LDL-cholesterol, blood pressure, and impaired kidney function are particularly frequent in old-aged individuals. However, population-based data on the extent of cardiovascular risk factor control in the old-aged population is limited. AugUR is a cohort of the mobile "70+"-year-old population of/near Regensburg, recruited via population registries. We conducted cross-sectional analyses assessing the proportion of AugUR participants with LDL-cholesterol, HbA1c, or blood pressure beyond recommended levels and their association with impaired creatinine- and cystatin-based estimated glomerular filtration rate (eGFR, <60 mL/min/1.73 m2) or urine albumin-creatinine ratio (UACR, ≥30 mg/g). Among 2215 AugUR participants, 74.7% were taking lipid-, glucose-, blood-pressure-lowering, or diuretic medication. High LDL-cholesterol at ≥116 mg/dL was observed for 76.1% (51.1% among those with prior cardiovascular events). We found HbA1c ≥ 7.0% for 6.3%, and high or low systolic blood pressure for 6.8% or 26.5%, respectively (≥160, <120 mmHg). Logistic regression revealed (i) high HbA1c levels associated with increased risk for impaired kidney function among those untreated, (ii) high blood pressure with increased UACR, and (iii) low blood pressure with impaired eGFR, which was confined to individuals taking diuretics. Our results provide important insights into cardiovascular risk factor control in individuals aged 70-95 years, which are understudied in most population-based studies.

Photostress Recovery Time as a Potential Predictive Biomarker for Age-Related Macular Degeneration.

Purpose: The purpose of this study was to assess recovery time following photostress and its association with age-related macular degeneration (AMD) cross-sectionally and longitudinally in an elderly population-based cohort. Methods: We analyzed photostress recovery time (PRT) and AMD in >1800 AugUR study participants aged 70+ years. On color fundus images from baseline and 3-year follow-up, presence of AMD was graded manually (Three Continent AMD Consortium Severity Scale). Visual acuity (VA) was assessed via Early Treatment Diabetic Retinopathy Study (ETDRS) charts. After a 30-second bleaching of the macular region via direct ophthalmoscope, PRT was measured as the seconds to regain VA. Results: First, we analyzed 1208 AugUR participants cross-sectionally (288 with early AMD, and 78 with late AMD). Prolonged PRT was associated with early and late AMD versus no AMD (median PRT = 119.5, 198.0 versus 80.0 seconds, respectively; logistic regression odds ratio [OR] = 1.109-1.165 per 10 seconds, P values < 0.0001). Sensitivity analyses using alternative models or restricting to participants after cataract surgery revealed similar ORs. Second, the association was confirmed in an independent cross-sectional AugUR sample (n = 486). Third, in longitudinal analysis of 233 AugUR participants without AMD, prolonged PRT was associated with incident AMD ascertained 3 years later (follow-up time = 3.2 ± 0.2 years, OR = 1.112-1.162 per 10 seconds, P < 0.05). Overall, we demonstrate a significant association of prolonged PRT with AMD cross-sectionally and longitudinally in elderly individuals. Conclusions: Prolonged PRT might capture retinal function impairment after cell damage before early AMD is visible via color fundus imaging. Translational Relevance: Our results suggest PRT as quantitative predictive biomarker for incident AMD, making it potentially worthwhile also for clinical care.

Association of lipid-lowering drugs and antidiabetic drugs with age-related macular degeneration: a meta-analysis in Europeans.

BACKGROUND/AIMS: To investigate the association of commonly used systemic medications with prevalent age-related macular degeneration (AMD) in the general population. METHODS: We included 38 694 adults from 14 population-based and hospital-based studies from the European Eye Epidemiology consortium. We examined associations between the use of systemic medications and any prevalent AMD as well as any late AMD using multivariable logistic regression modelling per study and pooled results using random effects meta-analysis. RESULTS: Between studies, mean age ranged from 61.5±7.1 to 82.6±3.8 years and prevalence ranged from 12.1% to 64.5% and from 0.5% to 35.5% for any and late AMD, respectively. In the meta-analysis of fully adjusted multivariable models, lipid-lowering drugs (LLD) and antidiabetic drugs were associated with lower prevalent any AMD (OR 0.85, 95% CI=0.79 to 0.91 and OR 0.78, 95% CI=0.66 to 0.91). We found no association with late AMD or with any other medication. CONCLUSION: Our study indicates a potential beneficial effect of LLD and antidiabetic drug use on prevalence of AMD across multiple European cohorts. Our findings support the importance of metabolic processes in the multifactorial aetiology of AMD.

Self-report of chronic diseases in old-aged individuals: extent of agreement with general practitioner medical records in the German AugUR study.

BACKGROUND: To estimate prevalence and incidence of diseases through self-reports in observational studies, it is important to understand the accuracy of participant reports. We aimed to quantify the agreement of self-reported and general practitioner-reported diseases in an old-aged population and to identify socio-demographic determinants of agreement. METHODS: This analysis was conducted as part of the AugUR study (n=2449), a prospective population-based cohort study in individuals aged 70-95 years, including 2321 participants with consent to contact physicians. Self-reported chronic diseases of participants were compared with medical data provided by their respective general practitioners (n=589, response rate=25.4%). We derived overall agreement, over-reporting/under-reporting, and Cohen's kappa and used logistic regression to evaluate the dependency of agreement on participants' sociodemographic characteristics. RESULTS: Among the 589 participants (53.1% women), 96.9% reported at least one of the evaluated chronic diseases. Overall agreement was >80% for hypertension, diabetes, myocardial infarction, stroke, cancer, asthma, bronchitis/chronic obstructive pulmonary disease and rheumatoid arthritis, but lower for heart failure, kidney disease and arthrosis. Cohen's kappa was highest for diabetes and cancer and lowest for heart failure, musculoskeletal, kidney and lung diseases. Sex was the primary determinant of agreement on stroke, kidney disease, cancer and rheumatoid arthritis. Agreement for myocardial infarction and stroke was most compromised by older age and for cancer by lower educational level. CONCLUSION: Self-reports may be an effective tool to assess diabetes and cancer in observational studies in the old and very old aged. In contrast, self-reports on heart failure, musculoskeletal, kidney or lung diseases may be substantially imprecise.

Relative Telomere Length Is Associated With Age-Related Macular Degeneration in Women.

Purpose: Relative telomere length (RTL) is a biomarker for physiological aging. Premature shortening of telomeres is associated with oxidative stress, which is one possible pathway that might contribute to age-related macular degeneration (AMD). We therefore aimed to investigate the association between RTL and AMD in a well-characterized group of elderly individuals. Methods: We measured RTL in participants of the AugUR study using a multiplex quantitative PCR-based assay determining the ratio between the telomere product and a single-copy gene product (T/S ratio). AMD was assessed by manual grading of color fundus images using the Three Continent AMD Consortium Severity Scale. Results: Among the 2262 individuals 70 to 95 years old (627 with AMD and 1635 without AMD), RTL was significantly shorter in individuals with AMD compared to AMD-free participants. In age- and sex-adjusted logistic regression analyses, we observed an 8% higher odds for AMD per 0.1 unit shorter RTL (odds ratio [OR] = 1.08; 95% confidence interval [CI], 1.02-1.14; P = 0.005). The estimates remained stable when adjusted for smoking, high-density lipoprotein cholesterol, cardiovascular disease, diabetes, and hypertension. Interestingly, this association was only present in women (OR = 1.14; 95% CI, 1.06-1.23; P < 0.001), but not in men (OR = 1.01; 95% CI, 0.93-1.10; P = 0.76). A significant sex-by-RTL interaction on AMD was detected (P = 0.043). Conclusions: Our results show an association of RTL with AMD that was restricted to women. This is in line with altered reactive oxygen species levels and higher telomerase activity in women and provides an indication for a sex-differential pathway for oxidative stress and AMD.

Incidence, progression and risk factors of age-related macular degeneration in 35-95-year-old individuals from three jointly designed German cohort studies.

OBJECTIVE: To estimate age-related macular degeneration (AMD) incidence/progression across a wide age range. METHODS AND ANALYSIS: AMD at baseline and follow-up (colour fundus imaging, Three Continent AMD Consortium Severity Scale, 3CACSS, clinical classification, CC) was assessed for 1513 individuals aged 35-95 years at baseline from three jointly designed population-based cohorts in Germany: Kooperative Gesundheitsforschung in der Region Augsburg (KORA-Fit, KORA-FF4) and Altersbezogene Untersuchungen zur Gesundheit der Universität Regensburg (AugUR) with 18-year, 14-year or 3-year follow-up, respectively. Baseline assessment included lifestyle, metabolic and genetic markers. We derived cumulative estimates, rates and risk factor association for: (1) incident early AMD, (2) incident late AMD among no AMD at baseline (definition 1), (3) incident late AMD among no/early AMD at baseline (definition 2), (4) progression from early to late AMD. RESULTS: Incidence/progression increased by age, except progression in 70+-year old. We observed 35-55-year-old with 3CACSS-based early AMD who progressed to late AMD. Predominant risk factor for incident late AMD definition 2 was early AMD followed by genetics and smoking. When separating incident late AMD definition 1 from progression (instead of combined as incident late AMD definition 2), estimates help judge an individual's risk based on age and (3CACSS) early AMD status: for example, for a 65-year old, 3-year late AMD risk with no or early AMD is 0.5% or 7%, 3-year early AMD risk is 3%; for an 85-year old, these numbers are 0.5%, 21%, 12%, respectively. For CC-based 'early/intermediate' AMD, incidence was higher, but progression was lower. CONCLUSION: We provide a practical guide for AMD risk for ophthalmology practice and healthcare management and document a late AMD risk for individuals aged <55 years.

Changes in healthcare seeking and lifestyle in old aged individuals during COVID-19 lockdown in Germany: the population-based AugUR study.

BACKGROUND: Containment measures in the COVID-19 pandemic protected individuals at high risk, particularly individuals at old age, but little is known about how these measures affected health-related behavior of old aged individuals. We aimed to investigate the impact of the spring 2020 lockdown in Germany on healthcare-seeking and health-related lifestyle in the old aged and to identify susceptible subgroups. METHODS: We conducted a follow-up survey among the pre-pandemically well-characterized participants of our AugUR cohort study, residents in/around Regensburg aged 70+ years and relatively mobile. A self-completion questionnaire on current behavior, perceived changes, and SARS-Cov-2 infection was mailed in May 2020, shortly before contact restrictions ended. Pre-pandemic lifestyle and medical conditions were derived from previous study center visits. RESULTS: Among 1850 survey participants (73-98 years; net-response 89%), 74% were at increased risk for severe COVID-19 according to medical conditions; four participants reported SARS-CoV-2 infection (0.2%). Participants reported changes in behavior: 29% refrained from medical appointments, 14% increased TV consumption, 26% reported less physical activity, but no systematic increase of smoking or alcohol consumption. When comparing during- and pre-lockdown reports of lifestyle within participant, we found the same pattern as for the reported perceived changes. Women and the more educated were more susceptible to changes. Worse QOL was perceived by 38%. CONCLUSIONS: Our data suggest that the spring 2020 lockdown did not affect the lifestyle of a majority of the mobile old aged individuals, but the substantial proportions with decreased physical activity and healthcare-seeking are markers of collateral damage.

Physical Activity, Incidence, and Progression of Age-Related Macular Degeneration: A Multicohort Study.

PURPOSE: To investigate the impact of physical activity (PA) on the incidence or progression of age-related macular degeneration (AMD) in the general population. DESIGN: Meta-analysis of longitudinal cohort studies. METHODS: We included 14,630 adults with no or early AMD at baseline from 7 population-based studies and examined associations of PA with AMD incidence and progression using multistate models (MSM) per study and subsequent random effects meta-analysis. Age effects were assessed using meta-regression. The main outcome measure was the hazard ratio (HR) for incident early or progression to late AMD. RESULTS: At baseline, mean age was 60.7 ± 6.9 to 76.4 ± 4.3 years, and prevalence of early AMD was 7.7% (range, 3.6%-16.9%) between cohorts. During follow-up, 1461 and 189 events occurred for early and late AMD, respectively. In meta-analyses, no or low to moderate PA (high PA as reference) was associated with an increased risk for incident early AMD (HR, 1.19; 95% CI, 1.01-1.40; P = .04), but not for late AMD. In subsequent meta-regression, we found no association of age with the effect of PA on incident AMD. CONCLUSIONS: Our study suggests high levels of PA to be protective for the development of early AMD across several population-based cohort studies. Our results establish PA as a modifiable risk factor for AMD and inform further AMD prevention strategies to reduce its public health impact.

Distribution and specificity of high-sensitivity cardiac troponin T in older adults without acute cardiac conditions: cross-sectional results from the population-based AugUR study.

OBJECTIVE: European guidelines recommended a uniform upper reference limit of high-sensitivity cardiac troponin T (hsTnT) to rule out non-ST segment elevation myocardial infarction. Our study aimed to provide a hsTnT reference distribution and to assess the specificity of the 14 ng/L cut-off value in the mobile population ≥70 years of age. DESIGN: A cross-sectional analysis was performed in the German AugUR study (Altersbezogene Untersuchungen zur Gesundheit der University of Regensburg). SETTING: Study population was the mobile population aged 70+ years living in the city and county of Regensburg, Germany. PARTICIPANTS: A random sample was derived from the local population registries of residence. Of the 5644 individuals invited, 1133 participated (response ratio=20.1%). All participants came to the study centre and were mentally and physically mobile to conduct the protocol (face-to-face interview, blood draw and standardised transthoracic echocardiography). None of the participants was in an acute state of myocardial infarction. RESULTS: Among the 1129 individuals with hsTnT measurements (overall median=10.0 ng/L(25th, 75th percentile)=(7.0, 15.0 ng/L)), hsTnT was higher among the older individuals and higher among men (men 70-74 years median=9.6 ng/L (7.2, 13.1 ng/L); men 90-95 years median=21.2 ng/L (14.6, 26.0 ng/L); women 70-74 years median=6.3 ng/L (4.7, 8.7 ng/L); and women 90-95 years median=18.0 ng/L (11.0, 21.0 ng/L)). In participants with impaired kidney function (eGFRcrea <60 mL/min/1.73 m2), hsTnT was elevated (median=13.6 ng/L (9.4, 20.6 ng/L)).Specificity of recommended upper reference limit, 14 ng/L, is 68%. Most false positives were among men aged >79 years (specificity=34%). In a healthy subgroup (n=96, none of the following: overt heart disease, impaired renal function, blood pressure >160/100 mm Hg, left ventricular hypertrophy and diastolic/systolic dysfunction), specificity was 90%. CONCLUSION: In the elderly population without acute myocardial infarction, hsTnT further increases with age showing different levels for men and women. The specificity of the 14 ng/L cut-off is considerably lower than 99%, even in healthy subjects.

Genome-wide association meta-analysis for early age-related macular degeneration highlights novel loci and insights for advanced disease.

BACKGROUND: Advanced age-related macular degeneration (AMD) is a leading cause of blindness. While around half of the genetic contribution to advanced AMD has been uncovered, little is known about the genetic architecture of early AMD. METHODS: To identify genetic factors for early AMD, we conducted a genome-wide association study (GWAS) meta-analysis (14,034 cases, 91,214 controls, 11 sources of data including the International AMD Genomics Consortium, IAMDGC, and UK Biobank, UKBB). We ascertained early AMD via color fundus photographs by manual grading for 10 sources and via an automated machine learning approach for > 170,000 photographs from UKBB. We searched for early AMD loci via GWAS and via a candidate approach based on 14 previously suggested early AMD variants. RESULTS: Altogether, we identified 10 independent loci with statistical significance for early AMD: (i) 8 from our GWAS with genome-wide significance (P < 5 × 10- 8), (ii) one previously suggested locus with experiment-wise significance (P < 0.05/14) in our non-overlapping data and with genome-wide significance when combining the reported and our non-overlapping data (together 17,539 cases, 105,395 controls), and (iii) one further previously suggested locus with experiment-wise significance in our non-overlapping data. Of these 10 identified loci, 8 were novel and 2 known for early AMD. Most of the 10 loci overlapped with known advanced AMD loci (near ARMS2/HTRA1, CFH, C2, C3, CETP, TNFRSF10A, VEGFA, APOE), except two that have not yet been identified with statistical significance for any AMD. Among the 17 genes within these two loci, in-silico functional annotation suggested CD46 and TYR as the most likely responsible genes. Presence or absence of an early AMD effect distinguished the known pathways of advanced AMD genetics (complement/lipid pathways versus extracellular matrix metabolism). CONCLUSIONS: Our GWAS on early AMD identified novel loci, highlighted shared and distinct genetics between early and advanced AMD and provides insights into AMD etiology. Our data provide a resource comparable in size to the existing IAMDGC data on advanced AMD genetics enabling a joint view. The biological relevance of this joint view is underscored by the ability of early AMD effects to differentiate the major pathways for advanced AMD.

Chances and challenges of machine learning-based disease classification in genetic association studies illustrated on age-related macular degeneration.

Imaging technology and machine learning algorithms for disease classification set the stage for high-throughput phenotyping and promising new avenues for genome-wide association studies (GWAS). Despite emerging algorithms, there has been no successful application in GWAS so far. We establish machine learning-based phenotyping in genetic association analysis as misclassification problem. To evaluate chances and challenges, we performed a GWAS based on automatically classified age-related macular degeneration (AMD) in UK Biobank (images from 135,500 eyes; 68,400 persons). We quantified misclassification of automatically derived AMD in internal validation data (4,001 eyes; 2,013 persons) and developed a maximum likelihood approach (MLA) to account for it when estimating genetic association. We demonstrate that our MLA guards against bias and artifacts in simulation studies. By combining a GWAS on automatically derived AMD and our MLA in UK Biobank data, we were able to dissect true association (ARMS2/HTRA1, CFH) from artifacts (near HERC2) and identified eye color as associated with the misclassification. On this example, we provide a proof-of-concept that a GWAS using machine learning-derived disease classification yields relevant results and that misclassification needs to be considered in analysis. These findings generalize to other phenotypes and emphasize the utility of genetic data for understanding misclassification structure of machine learning algorithms.

[Mutation-Dependent Mechanisms and Their Impact on Targeted Therapeutic Strategies with Reference to Bestrophin 1 and the Bestrophinopathies]. / Mutationsabhängige Mechanismen und deren Bedeutung für zielgerichtete Behandlungsstrategien am Beispiel von Bestrophin 1 und den Bestrophinopathien.

Bestrophin 1 (BEST1) encodes an integral membrane protein localized in the basolateral aspect of the retinal pigment epithelium. Mutations in BEST1 are associated with distinct retinal dystrophies, the so-called "bestrophinopathies", often causing visual impairment, even in early childhood. The clinical entities of the bestrophinopathies can be distinguished by phenotypic characteristics and mode of inheritance of the respective gene defect. While the autosomal dominant inheritance pattern with one altered copy of BEST1 is common, heterozygous carriers of the autosomal recessive bestrophinopathy are generally but not consistently symptom-free. This review highlights the significance of understanding the underlying molecular mechanisms that contribute to disease pathogenesis of autosomal dominant and autosomal recessive bestrophinopathies. This knowledge is deemed crucial and needs to be considered in future planning of treatment strategies.

Mutation-Dependent Pathomechanisms Determine the Phenotype in the Bestrophinopathies.

Best vitelliform macular dystrophy (BD), autosomal dominant vitreoretinochoroidopathy (ADVIRC), and the autosomal recessive bestrophinopathy (ARB), together known as the bestrophinopathies, are caused by mutations in the bestrophin-1 (BEST1) gene affecting anion transport through the plasma membrane of the retinal pigment epithelium (RPE). To date, while no treatment exists a better understanding of BEST1-related pathogenesis may help to define therapeutic targets. Here, we systematically characterize functional consequences of mutant BEST1 in thirteen RPE patient cell lines differentiated from human induced pluripotent stem cells (hiPSCs). Both BD and ARB hiPSC-RPEs display a strong reduction of BEST1-mediated anion transport function compared to control, while ADVIRC mutations trigger an increased anion permeability suggesting a stabilized open state condition of channel gating. Furthermore, BD and ARB hiPSC-RPEs differ by the degree of mutant protein turnover and by the site of subcellular protein quality control with adverse effects on lysosomal pH only in the BD-related cell lines. The latter finding is consistent with an altered processing of catalytic enzymes in the lysosomes. The present study provides a deeper insight into distinct molecular mechanisms of the three bestrophinopathies facilitating functional categorization of the more than 300 known BEST1 mutations that result into the distinct retinal phenotypes.

Response misclassification in studies on bilateral diseases.

Misclassification in binary outcomes can severely bias effect estimates of regression models when the models are naively applied to error-prone data. Here, we discuss response misclassification in studies on the special class of bilateral diseases. Such diseases can affect neither, one, or both entities of a paired organ, for example, the eyes or ears. If measurements are available on both organ entities, disease occurrence in a person is often defined as disease occurrence in at least one entity. In this setting, there are two reasons for response misclassification: (a) ignorance of missing disease assessment in one of the two entities and (b) error-prone disease assessment in the single entities. We investigate the consequences of ignoring both types of response misclassification and present an approach to adjust the bias from misclassification by optimizing an adequate likelihood function. The inherent modelling assumptions and problems in case of entity-specific misclassification are discussed. This work was motivated by studies on age-related macular degeneration (AMD), a disease that can occur separately in each eye of a person. We illustrate and discuss the proposed analysis approach based on real-world data of a study on AMD and simulated data.