Prevalence of age-related macular degeneration in old persons: Age, Gene/environment Susceptibility Reykjavik Study

Aging of the eye: Lessons from cataracts and age-related macular degeneration

Aging is the greatest risk factor for chronic human diseases, including many eye diseases. Geroscience aims to understand the effects of the aging process on these diseases, including the genetic, molecular, and cellular mechanisms that underlie the increased risk of disease over the lifetime. Understanding of the aging eye increases general knowledge of the cellular physiology impacted by aging processes at various biological extremes. Two major diseases, age-related cataract and age-related macular degeneration (AMD) are caused by dysfunction of the lens and retina, respectively. Lens transparency and light refraction are mediated by lens fiber cells lacking nuclei and other organelles, which provides a unique opportunity to study a single aging hallmark, i.e., loss of proteostasis, within an environment of limited metabolism. In AMD, local dysfunction of the photoreceptors/retinal pigmented epithelium/Bruch's membrane/choriocapillaris complex in the macula leads to the loss of photoreceptors and eventually loss of central vision, and is driven by nearly all the hallmarks of aging and shares features with Alzheimer's disease, Parkinson's disease, cardiovascular disease, and diabetes. The aging eye can function as a model for studying basic mechanisms of aging and, vice versa, well-defined hallmarks of aging can be used as tools to understand age-related eye disease.

The Burden of Cardiovascular Diseases Due to COVID-19 Pandemic

The coronavirus disease 2019 (COVID-19) is an infection caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that produces respiratory symptoms and has serious consequences for people's cardiovascular systems (CVS). It is a severe issue and a major task not only for health care experts but also for governments to contain this pandemic. SARS-CoV-2 is the seventh member of the human coronavirus family to be implicated in this zoonotic outbreak. COVID-19's CV interactions are comparable to those of SARS-CoV, Middle East respiratory syndrome (MERS-CoV), and influenza. Those who have COVID-19 and underlying cardiovascular diseases (CVDs) are at a higher risk of serious illness and mortality, and disease has been linked to several direct and indirect CV consequences. COVID-19 causes CVDs such as arrhythmias, cardiac arrest, cardiogenic shock, myocarditis, stress-cardiomyopathy, and acute myocardial damage (AMD) as a consequence of acute coronary syndrome. The provision of CV care may expose health care professionals to risk as they become hosts or vectors of viral transmission. It binds to the angiotensin-converting enzyme receptor, causing constitutional and pulmonary signs in the beginning, and then as the infection advances, it affects other organs such as the gastrointestinal tract, CVS, neurological system, and so on. COVID-19 mortality is increased by underlying CVDs comorbidities.

Prevalence of geographic atrophy in Nordic countries and number of patients potentially eligible for intravitreal complement inhibitor treatment: A systematic review with meta-analyses and forecasting study

We systematically reviewed the literature on the prevalence of geographic atrophy (GA) in Nordic populations, conducted meta-analyses on age-stratified estimates, and calculated current and future number of patients and those potentially eligible for intravitreal complement inhibitor treatment. We followed the PRISMA guidelines, and our protocol was registered in PROSPERO. Ten databases were searched on 22 April 2023 for population-based studies of GA prevalence. Based on clinical descriptive analyses of GA and eligibility criteria of the phase III studies for intravitreal pegcetacoplan (complement C3 and C3b inhibitor), we were able to calculate the proportion of patients with GA potentially eligible for therapy. Finally, we extracted population data for Nordic countries (Denmark, Finland, Iceland, Norway, and Sweden) from Eurostat, applied prevalence statistics to the extracted census and forecasting data to estimate the number of patients with GA, and then applied the proportion eligible for intravitreal pegcetacoplan therapy. We identified six studies with a total of 10 159 individuals. Prevalence of GA was estimated to 0.4% (95% confidence intervals [CI]: 0.2%-0.8%), 1.5% (95% CI: 0.7%-2.6%), and 7.6% (95% CI: 4.6%-11.3%) for individuals aged 60-69, 70-79, and 80+ years, respectively. In Nordic countries, we estimate a total of 166 307 individuals with GA in 2023, increasing to 277 893 in 2050. Of these, 90 803 individuals in 2023, increasing to 151 730 in 2050, are potentially eligible for intravitreal complement inhibitor treatment. Considering these large numbers, our study highlights the importance of this topic in the coming years and its potential to significantly impact our clinical practice, organization, and staffing.

Age-related macular degeneration is associated with probable cerebral amyloid angiopathy: A case-control study

BACKGROUND

Age-related macular degeneration (AMD) is a common retinal degenerative disorder among older individuals. Amyloid deposits, a hallmark of cerebral amyloid angiopathy (CAA), may be involved in the pathogenesis of AMD. Since amyloid deposits may contribute to the development of both AMD and CAA, we hypothesized that patients with AMD have a higher prevalence of CAA.

OBJECTIVE

To compare the prevalence of CAA in patients with or without AMD matched for age.

METHODS

We conducted a cross-sectional, 1:1 age-matched, case-control study of patients ≥40 years of age at the Mayo Clinic who had undergone both retinal optical coherence tomography and brain MRI from 2011 to 2015. Primary dependent variables were probable CAA, superficial siderosis, and lobar and deep cerebral microbleeds (CMBs). The relationship between AMD and CAA was assessed using multivariable logistic regression and was compared across AMD severity (none vs early vs late AMD).

RESULTS

Our analysis included 256 age-matched pairs (AMD 126, no AMD 130). Of those with AMD, 79 (30.9%) had early AMD and 47 (19.4%) had late AMD. The mean age was 75±9 years, and there was no significant difference in vascular risk factors between groups. Patients with AMD had a higher prevalence of CAA (16.7% vs 10.0%, p=0.116) and superficial siderosis (15.1% vs 6.2%, p=0.020), but not deep CMB (5.2% vs 6.2%, p=0.426), compared to those without AMD. After adjusting for covariates, having late AMD was associated with increased odds of CAA (OR 2.83, 95% CI 1.10-7.27, p=0.031) and superficial siderosis (OR 3.40, 95%CI 1.20-9.65, p=0.022), but not deep CMB (OR 0.7, 95%CI 0.14-3.51, p=0.669).

CONCLUSIONS

AMD was associated with CAA and superficial siderosis but not deep CMB, consistent with the hypothesis that amyloid deposits play a role in the development of AMD. Prospective studies are needed to determine if features of AMD may serve as biomarkers for the early diagnosis of CAA.

Incidence and Prevalence of Neovascular Age-Related Macular Degeneration in France between 2008 and 2018

Purpose

This study aimed to estimate the incidence and prevalence of neovascular age-related macular degeneration (nAMD) in the French population between 2008 and 2018.

Design

This was a retrospective, longitudinal population study using health care consumption data from the Système National des Données de Santé (SNDS; the French National Health Information Database), which covers approximately 99% of the French population.

Participants

We identified individuals treated for nAMD from the French population 50 years of age and older. Identification criteria were nAMD diagnosis or reimbursement of nAMD treatments (anti–vascular endothelial growth factor intravitreal injection or dynamic phototherapy with verteporfin). Exclusion criteria were high myopia, diagnosis of other retinal diseases, and other treatments for macular diseases (dexamethasone implant, laser therapy, etc.).

Methods

We calculated incidence and prevalence based on the age-matched general population in France. Adjustment for age and sex was also performed for incidence.

Main Outcome Measures

Incidence and prevalence of nAMD in the French population between 2008 and 2018.

Results

Between 2008 and 2018, we identified 342 961 patients with nAMD (67.5% women). Mean ± standard deviation age at nAMD diagnosis or first treatment increased from 78.8 ± 8.1 years in 2008 to 81.2 ± 7.9 years in 2018. In 2018, annual incidence was 0.149% and prevalence was 1.062% for the French population 50 years of age or older. Incidence was stable over the 10-year period. Annual incidence increased with age (0.223%, 0.380%, and 0.603% in those 60 years of age or older, 70 years of age or older, and 80 years of age or older, respectively), with similar trends for prevalence. No major differences were observed among the 14 regions of France for incidence or prevalence. Neovascular age-related macular degeneration incidence in 2018 was not impacted by the availability of primary or ophthalmology care in patients’ localities.

Conclusions

The LANDSCAPE study provides exhaustive nationwide data on incidence and prevalence of nAMD in France over a 10-year period.

The emerging role of extracellular vesicles in retinal diseases

As a type of nanosized membranous vesicles secreted by living cells, extracellular vesicles (EVs) mediate intercellular communications with excellent physicochemical stability and biocompatibility. By delivering biologically active molecules including proteins, nucleic acids and lipids, EVs participate in many physiological and pathological processes. Increasing studies have suggested that EVs may be biomarkers for liquid biopsy of retinal diseases due to the ability to transfer through the blood-retinal barrier. EVs also represent a novel cell-free strategy to repair tissue damage in regenerative medicine. Evidence has indicated that EVs can be engineered and modified to enhance their efficacy. In this review, an overview of the characteristics, isolation, and identification of EVs is provided. Moreover, recent advances with EVs in the diagnosis and treatment of retinal diseases and the engineering approaches to elevate their effects are introduced, and opportunities and challenges for clinical application are discussed.

Deletion of TSPO Causes Dysregulation of Cholesterol Metabolism in Mouse Retina

Cholesterol dysregulation has been implicated in age-related macular degeneration (AMD), the most common cause of visual impairment in the elderly. The 18 KDa translocator protein (TSPO) is a mitochondrial outer membrane protein responsible for transporting cholesterol from the mitochondrial outer membrane to the inner membrane. TSPO is highly expressed in retinal pigment epithelial (RPE) cells, and TSPO ligands have shown therapeutic potential for the treatment of AMD. Here, we characterized retinal pathology of Tspo knockout (KO) mice using histological, immunohistochemical, biochemical and molecular biological approaches. We found that Tspo KO mice had normal retinal morphology (by light microscopy) but showed elevated levels of cholesterol, triglycerides and phospholipids with perturbed cholesterol efflux in the RPE cells of Tspo KO mice. Expression of cholesterol-associated genes (Nr1h3, Abca1, Abcg1, Cyp27a1 and Cyp46a1) was significantly downregulated, and production of pro-inflammatory cytokines was markedly increased in Tspo KO retinas. Furthermore, microglial activation was also observed in Tspo KO mouse retinas. These findings provide new insights into the function of TSPO in the retina and may aid in the design of new therapeutic strategies for the treatment of AMD.

Effect of a TSPO ligand on retinal pigment epithelial cholesterol homeostasis in high-fat fed mice, implication for age-related macular degeneration

Age-related Macular Degeneration (AMD) is a major cause of sight impairment in the elderly with complex aetiology involving genetics and environment and with limited therapeutic options which have limited efficacy. We have previously shown in a mouse-model of the condition, induced by feeding a high fat diet, that adverse effects of the diet can be reversed by co-administration of the TSPO activator, etifoxine. We extend those observations showing improvements in retinal pigment epithelial (RPE) cells with decreased lipids and enhanced expression of cholesterol metabolism and transport enzymes. Further, etifoxine decreased levels of reactive oxygen species (ROS) in RPE and inflammatory cytokines in RPE and serum. With respect to gut microbiome, we found that organisms abundant in the high fat condition (e.g. in the genus Anaerotruncus and Oscillospira) and implicated in AMD, were much less abundant after etifoxine treatment. The changes in gut flora were associated with the predicted production of metabolites of benefit to the retina including tryptophan and other amino acids and taurine, an essential component of the retina necessary to counteract ROS. These novel observations strengthen earlier conclusions that the mechanisms behind improvements in etifoxine-induced retinal physiology involve an interaction between effects on the host and the gut microbiome.

RNA therapeutics in ophthalmology - translation to clinical trials

The use of RNA interference technology has proven to inhibit the expression of many target genes involved in the underlying pathogenesis of several diseases affecting various systems. First established in in vitro and later in animal studies, small interfering RNA (siRNA) and antisense oligonucleotide (ASO) therapeutics are now entering clinical trials with the potential of clinical translation to patients. Gene-silencing therapies have demonstrated promising responses in ocular disorders, predominantly due to the structure of the eye being a closed and compartmentalised organ. However, although the efficacy of such treatments has been observed in both preclinical studies and clinical trials, there are issues pertaining to the use of these drugs which require more extensive research with regards to the delivery and stability of siRNAs and ASOs. This would improve their use for long-term treatment regimens and alleviate the difficulties experienced by patients with ocular diseases. This review provides a detailed insight into the recent developments and clinical trials that have been conducted for several gene-silencing therapies, including ISTH0036, SYL040012, SYL1001, PF-04523655, Sirna-027, QR-110, QR-1123, QR-421a and IONIS-FB-L_RX in glaucoma, dry eye disease, age-related macular degeneration, diabetic macular oedema and various inherited retinal diseases. Our aim is to explore the potential of these drugs whilst evaluating their associated advantages and disadvantages, and to discuss the future translation of RNA therapeutics in ophthalmology.

Not All Stressors Are Equal: Mechanism of Stressors on RPE Cell Degeneration

Age-related macular degeneration (AMD) is a major cause of irreversible blindness among the elderly population. Dysfunction and degeneration of the retinal pigment epithelial (RPE) layer in the retina underscore the pathogenesis of both dry and wet AMD. Advanced age, cigarette smoke and genetic factors have been found to be the prominent risk factors for AMD, which point to an important role for oxidative stress and aging in AMD pathogenesis. However, the mechanisms whereby oxidative stress and aging lead to RPE cell degeneration are still unclear. As cell senescence and cell death are the major outcomes from oxidative stress and aging, here we review the mechanisms of RPE cell senescence and different kinds of cell death, including apoptosis, necroptosis, pyroptosis, ferroptosis, with an aim to clarify how RPE cell degeneration could occur in response to AMD-related stresses, including H₂O₂, 4-Hydroxynonenal (4-HNE), N-retinylidene-N-retinyl-ethanolamine (A2E), Alu RNA and amyloid β (Aβ). Besides those, sodium iodate (NaIO₃) induced RPE cell degeneration is also discussed in this review. Although NaIO₃ itself is not related to AMD, this line of study would help understand the mechanism of RPE degeneration.

Body size at birth and age-related macular degeneration in old age

PURPOSE

To study associations between body size at birth and age-related macular degeneration (AMD) in old age.

METHODS

The study sample consists of 1497 community-dwelling individuals (56.1% women) aged 67-89 years with birth data and retinal data collected twice in old age 5 years apart. Birth data (weight, length, birth order) were extracted from original birth records. Digital retinal photographs were graded to determine AMD status. Data on covariates were collected at the baseline physical examination in old age. Multivariable regression analyses were used to study the association between birth data and AMD adjusting for known confounding factors, including birth year cohort effects.

RESULTS

The prevalence and 5-year incidence of any AMD were 33.1% and 17.0%, respectively. Men and women born in 1930-1936 were significantly leaner and slightly longer at birth compared to those in earlier birth cohorts. There were no consistent associations between weight, length or ponderal index (PI) at birth and AMD in old age even when stratified by birth cohort. Age-related macular degeneration (AMD) prevalence (39.8%) and 5-year incidence (28.6%) were highest in individuals who were in the highest quartile of PI at birth and who were obese in old age.

CONCLUSION

Body size at birth was not consistently associated with AMD in old age, suggesting that intrauterine growth might have little direct importance in the development of AMD in old age. It is possible that some yet unknown factors related to larger size at birth and obesity in old age may explain differences in the prevalence and incidence of AMD in the ageing population.

Prevalence and incidence of age-related macular degeneration in Europe: a systematic review and meta-analysis

BACKGROUND/AIMS

Age-related macular degeneration (AMD) is the main cause of visual impairment and blindness in Europe. A further increase in the number of affected persons is expected and current European data are needed for healthcare resource planning.

METHODS

We performed a systematic review on the prevalence and incidence of AMD based on the meta-analysis of observational studies in epidemiology guideline. Meta-analysis and meta-regression on time-trends, age, countries, regions, sex and classification systems for AMD were performed. Based on Eurostat population projections, the pooled prevalence estimates were extrapolated to the year 2050.

RESULTS

Twenty-two prevalence and four incidence studies published since 1996 were included. Our pooled prevalence estimate of early or intermediate AMD and any late AMD in those 60 years and older was 25.3% (95% CI 18.0% to 34.4%) and 2.4% (95% CI 1.8% to 3.3%), respectively. A significant increase in prevalence was seen in older populations. In the meta-analysis of incidence, the pooled annual incidence of any late AMD was 1.4 per 1 000 individuals (95% CI 0.8 to 2.6). Overall, the number of EU inhabitants with any AMD is expected to increase from 67 to 77 million until 2050. Incident late AMD is estimated to increase from 400 000 per year today to 700 000 per year in 2050.

CONCLUSIONS

Approximately 67 million people in the EU are currently affected by any AMD and, due to population ageing, this number is expected to increase by 15% until 2050. Monitoring and treatment of people with advanced disease stages will require additional healthcare resources and thorough healthcare planning in the years and decades to come.

Recent theranostic paradigms for the management of Age-related macular degeneration

Degenerative diseases of eye like Age-related macular degeneration (AMD), that affects the central portion of the retina (macula), is one of the leading causes of blindness worldwide especially in the elderly population. It is classified mainly as wet and dry form. With expanding knowledge about the underlying pathophysiology of the disease, various treatment strategies are being employed to halt the course of the disease progression. Hitherto, there is no ideal therapy which can cure the disease completely, and targeting the posterior segment of the eye is yet another challenge. The purpose of this review is to summarize the recent advances in the management and treatment stratagems (therapies, delivery systems and diagnostic tools) pertaining to AMD viz. molecular targeting, stem cell therapy, nanotechnology and exosomes with special reference to newer technologies like artificial intelligence and 3D printing. Furthermore, the role of diet and nutritional supplements in the prevention and treatment of the disease has also been highlighted. The alarming increase in the said disorder around the globe demands exhaustive research and investigations in the treatment zone. This review thus additionally directs the attention towards the challenges and future perspectives of different treatment approaches for AMD.

Molecular Mechanisms of Complement System Proteins and Matrix Metalloproteinases in the Pathogenesis of Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is an eye disorder affecting predominantly the older people above the age of 50 years in which the macular region of the retina deteriorates, resulting in the loss of central vision. The key factors associated with the pathogenesis of AMD are age, smoking, dietary, and genetic risk factors. There are few associated and plausible genes involved in AMD pathogenesis. Common genetic variants (with a minor allele frequency of >5% in the population) near the complement genes explain 40-60% of the heritability of AMD. The complement system is a group of proteins that work together to destroy foreign invaders, trigger inflammation, and remove debris from cells and tissues. Genetic changes in and around several complement system genes, including the CFH, contribute to the formation of drusen and progression of AMD. Similarly, Matrix metalloproteinases (MMPs) that are normally involved in tissue remodeling also play a critical role in the pathogenesis of AMD. MMPs are involved in the degradation of cell debris and lipid deposits beneath retina but with age their functions get affected and result in the drusen formation, succeeding to macular degeneration. In this review, AMD pathology, existing knowledge about the normal and pathological role of complement system proteins and MMPs in the eye is reviewed. The scattered data of complement system proteins, MMPs, drusenogenesis, and lipofusogenesis have been gathered and discussed in detail. This might add new dimensions to the understanding of molecular mechanisms of AMD pathophysiology and might help in finding new therapeutic options for AMD.

Systemic Levels of Interleukin-6 Correlate With Progression Rate of Geographic Atrophy Secondary to Age-Related Macular Degeneration

Purpose

Geographic atrophy (GA) is a clinical phenotype of late age-related macular degeneration (AMD) with no current treatment available. In this study, we investigated markers of chronic inflammation in plasma of patients with GA and how these relate to progression rate.

Methods

We prospectively included 42 patients with GA, 41 patients with neovascular AMD, and 27 healthy controls. We quantified levels of interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor (TNF) receptor 2, and C-reactive protein (CRP). We adapted an inflammation summary score to cluster conceptually related markers of chronic inflammation. Enlargement rate of the atrophic lesion was measured from fundus autofluorescence images performed at baseline and after 1 year.

Results

Patients with GA showed an increase in proinflammatory markers of IL-6 (P = 0.009), TNF receptor 2 (P = 0.013), and CRP (P = 0.017) compared to healthy controls. We found that IL-8 levels were markedly higher in patients with GA when compared to patients with neovascular AMD (P = 0.013). The inflammation summary score was high in patients with neovascular AMD (P = 0.024), but even higher in patients with GA (<0.001), when compared to healthy controls. GA enlargement was measured in 36 patients, who completed follow-up. Plasma levels of IL-6 had a moderate but significant correlation with GA enlargement rate (R2 = 0.23, P = 0.0035).

Conclusions

Markers of chronic inflammation strongly associates with presence of GA secondary to AMD. Plasma IL-6 possesses predictive ability of progression and constitutes the first known plasma biomarker of disease activity in GA. These findings shed light into a poorly understood clinical phenotype of AMD and highlights the important role of chronic inflammation in GA.

Meta-analysis of the rs243865 MMP-2 polymorphism and age-related macular degeneration risk

Purpose

Several researchers have suggested that the rs243865 (16q13-q21) polymorphism in the promoter region of the metalloproteinase-2 (MMP-2) gene could be associated with an increased risk of developing age-related macular degeneration (AMD). However, previous results remain inconclusive. To clarify this controversy, we conducted a meta-analysis of the relationship between rs243865 of MMP-2 and AMD.

Methods

We included 6 independent case-control studies involving 1,682 AMD patients and 2,295 healthy subjects. The association between the rs243865 polymorphism and AMD was examined by the overall odds ratio (OR) with a 95% confidence interval (CI). We used a recessive genetic model analysis, sensitivity analysis, and assessment of bias in our meta-analysis.

Results

Our results showed that there was no significant association between the variant T allele (p-value = 0.10, OR [95%CI] = 0.95 [0.82–1.10]) or the CT+TT genotype (p-value = 0.16, OR [95%CI] = 0.92 [0.76–1.12]) of rs243865 MMP-2 polymorphism and the presence of AMD.

Conclusions

The rs243865 MMP-2 polymorphism was not associated with an increased risk of developing AMD. The MMP-2 (-1306 C>T) promoter variant is unlikely to have a major role in AMD risk susceptibility.

Mechanisms Underlying the Visual Benefit of Cell Transplantation for the Treatment of Retinal Degenerations

The transplantation of retinal cells has been studied in animals to establish proof of its potential benefit for the treatment of blinding diseases. Photoreceptor precursors have been grafted in animal models of Mendelian-inherited retinal degenerations, and retinal pigmented epithelial cells have been used to restore visual function in animal models of age-related macular degeneration (AMD) and recently in patients. Cell therapy over corrective gene therapy in inherited retinal degeneration can overcome the genetic heterogeneity by providing one treatment for all genetic forms of the diseases. In AMD, the existence of multiple risk alleles precludes a priori the use of corrective gene therapy. Mechanistically, the experiments of photoreceptor precursor transplantation reveal the importance of cytoplasmic material exchange between the grafted cells and the host cells for functional rescue, an unsuspected mechanism and novel concept. For transplantation of retinal pigmented epithelial cells, the mechanisms behind the therapeutic benefit are only partially understood, and clinical trials are ongoing. The fascinating studies that describe the development of methodologies to produce cells to be grafted and demonstrate the functional benefit for vision are reviewed.

Serum lipids in adults with late age-related macular degeneration: a case-control study

Background

Lipids are implicated in the pathogenesis of age-related macular degeneration (AMD). The relationship between systemic lipids and AMD has not been well characterized. The objective was to investigate the relationship between serum lipids and AMD in older adults using a lipidomic approach.

Methods

In a case-control study, 240 adults, aged ≥66 years, a third each having geographic atrophy, neovascular AMD, or no signs of AMD, were selected from a population-based sample of participants in the Age Gene/Environment Susceptibility-Reykjavik Study. The exposure was serum lipids and risk factors for AMD. The outcome was late AMD, assessed through fundus images taken through dilated pupils using a 45-degree digital camera and grading for neovascular AMD and geographic atrophy using the modified Wisconsin Age-Related Maculopathy Grading System.

Results

Of 177 serum lipid species measured, there were no significant differences in serum lipids between controls and those with geographic atrophy or neovascular AMD, respectively. Adults with neovascular AMD had higher total serum lysophosphatidylcholine (LPC) (P = 0.004) and serum LPC 18:0 (P = 0.0002) compared to those with geographic atrophy.

Conclusion

Late AMD was not characterized by alterations in systemic lipids compared with normal controls. These findings suggest that there may be differences in the LPC pathway between adults with neovascular AMD and geographic atrophy.

Electronic supplementary material

The online version of this article (10.1186/s12944-018-0954-7) contains supplementary material, which is available to authorized users.

Low incidence of choroidal neovascularization following subthreshold diode micropulse laser (SDM) in high-risk AMD

Purpose

To determine the incidence of new choroidal neovascularization (CNV) in eyes with dry age-related macular degeneration (AMD) following subthreshold diode micropulse laser (SDM).

Method

In an observational retrospective cohort study, the records of all patients active in the electronic medical records database were reviewed to identify eyes with dry AMD treated with SDM. Identified eyes were classified by simplified AREDS categories, and analyzed for the primary endpoint of new CNV after treatment.

Results

The EMR revealed SDM was offered to 373/392 (95%) patients with dry AMD and elected by 363/373 (97%) between 2008–2017. Follow up was available for 354/363 patients (547 eyes, 98%) (range 6–108 mos., avg. 22). CNV risk factors included age (median 84 years, 67% > 80); reticular pseudodrusen (214 eyes, 39%); AREDS category (78% category 3 and 4); and fellow eye CNV (128 eyes, 23%). New CNV developed in 9/547 eyes (1.6%, annualized rate 0.87%). Visual acuity was unchanged. There were no adverse treatment effects.

Summary

In a review of a large group of eyes with exceptionally high-risk AMD, SDM was followed by a very low incidence of new CNV. If confirmed by further study, SDM would offer a new and highly effective treatment to reduce the risk of vision loss from AMD.

On the impact of different approaches to classify age-related macular degeneration: Results from the German AugUR study

While age-related macular degeneration (AMD) poses an important personal and public health burden, comparing epidemiological studies on AMD is hampered by differing approaches to classify AMD. In our AugUR study survey, recruiting residents from in/around Regensburg, Germany, aged 70+, we analyzed the AMD status derived from color fundus images applying two different classification systems. Based on 1,040 participants with gradable fundus images for at least one eye, we show that including individuals with only one gradable eye (n = 155) underestimates AMD prevalence and we provide a correction procedure. Bias-corrected and standardized to the Bavarian population, late AMD prevalence is 7.3% (95% confidence interval = [5.4; 9.4]). We find substantially different prevalence estimates for “early/intermediate AMD” depending on the classification system: 45.3% (95%-CI = [41.8; 48.7]) applying the Clinical Classification (early/intermediate AMD) or 17.1% (95%-CI = [14.6; 19.7]) applying the Three Continent AMD Consortium Severity Scale (mild/moderate/severe early AMD). We thus provide a first effort to grade AMD in a complete study with different classification systems, a first approach for bias-correction from individuals with only one gradable eye, and the first AMD prevalence estimates from a German elderly population. Our results underscore substantial differences for early/intermediate AMD prevalence estimates between classification systems and an urgent need for harmonization.

Pleiotropic Effects of Risk Factors in Age-Related Macular Degeneration and Seemingly Unrelated Complex Diseases

Age-related macular degeneration (AMD) is a complex disease with both environmental and genetic factors influencing disease risk. Genome-wide case-control association studies, candidate gene analyses, and epidemiological studies reinforced the notion that AMD is predominantly a disease of an impaired complement system and an altered high-density lipoprotein (HDL) metabolism. Recent reports demonstrated the pleiotropic role of the complement system and HDL in complex diseases such as cardiovascular disease, autoimmune disorders, cancer, and Alzheimer's disease. In light of these findings, we explore current evidence for a shared genetic and environmental risk of AMD and unrelated complex diseases based on epidemiological studies. Shared risk factors may indicate common pathways in disease pathology and thus may have implications for novel treatment options of AMD pathology.

Suppression of aberrant choroidal neovascularization through activation of the aryl hydrocarbon receptor

The aryl hydrocarbon receptor (AhR) is a ligand activated transcription factor, initially discovered for its role in regulating xenobiotic metabolism. There is extensive evidence supporting a multi-faceted role for AhR, modulating physiological pathways important in cell health and disease. Recently we demonstrated that the AhR plays a role in the pathogenesis of age-related macular degeneration (AMD), the leading cause of vision loss in the elderly. We found that loss of AhR exacerbates choroidal neovascular (CNV) lesion formation in a murine model. Herein we tested the therapeutic impact of AhR activation on CNV lesion formation and factors associated with aberrant neovascularization. We screened a panel of synthetic drugs and endogenous AhR ligands, assessed their ability to activate AhR in choroidal endothelial cells, and inhibit angiogenesis in vitro. Drugs with an anti-angiogenic profile were then administered to a murine model of CNV. Two compounds, leflunomide and flutamide, significantly inhibited CNV formation concurrent with positive modifying effects on angiogenesis, inflammation, extracellular matrix remodeling, and fibrosis. These results validate the role of the AhR pathway in regulating CNV pathogenesis, identify mechanisms of AhR-based therapies in the eye, and argue in favor of developing AhR as a drug target for the treatment of neovascular AMD.

[Qualitative and quantitative study of ophthalmologic consultation in France: A multicenter descriptive survey]

This study aimed to precisely map current ophthalmologic consultation in France through systematic data collection in one consultation day. Nine ophthalmologic centers participated in the survey, performing 1148 observations of patients aged from 2 to 102 years old, with a mean of 55.12years old and a male/female distribution of 43.8 %/56.2 %. In general, the patients came in either spontaneously (28.8 %) or for follow-up (59.6 %). Emergency consultations comprised 5.7 % of all cases. Comorbidities or major risk factors were found. Most the patients already wore visual correction (82.6 %), mainly glasses (77.3 %). At the end of the consultation, 48.2 % received a prescription for new optical correction. During the interview, 53.3 % of patients reported visual symptoms, most frequently blurriness, distortion or loss of vision. 25.3 % of the patients experienced ocular symptoms such as pain, watery eyes or itching. An ophthalmic disease was the reason for the consultation in 77.1 % of all cases. Its management included medicinal and/or surgical treatment (45.6 % and10.5 % respectively). The necessary tests were performed on site the same day and only 2.6 % of the patients were given a prescription for additional testing to be performed elsewhere in a referral center. From a qualitatively and quantitatively representative sample, this survey describes ophthalmologic consultation in France today in terms of age, male/female distribution, reason for the visit, the proportion of visual correction and other diseases, diagnosis and treatment.

Differential associations between retinal signs and CMBs by location: The AGES-Reykjavik Study

OBJECTIVE

To test the hypothesis that age-related macular degeneration (AMD) and retinal microvascular signs are differentially associated with lobar and deep cerebral microbleeds (CMBs).

METHODS

CMBs in lobar regions indicate cerebral amyloid angiopathy (CAA). β-Amyloid deposits are implicated in both CAA and AMD. Deep CMBs are associated with hypertension, a major risk factor for retinal microvascular damage. This population-based cohort study included 2,502 participants in the Age, Gene/Environment Susceptibility (AGES)-Reykjavik Study who undertook binocular digital retinal photographs at baseline (2002-2006) to assess retinal microvascular signs and AMD and brain MRI scan at both baseline and follow-up (2007-2011) to assess CMBs. We assessed retinal microvascular lesion burden by counting the 3 retinal microvascular signs (focal arteriolar narrowing, arteriovenous nicking, and retinopathy) concurrently present in the participant. We used multiple logistic models to examine the association of baseline retinal pathology to incident CMBs detected at follow-up.

RESULTS

During an average 5.2 years of follow-up, 461 people (18.3%) developed new CMBs, including 293 in exclusively lobar regions and 168 in deep regions. Pure geographic atrophy was significantly associated with strictly lobar CMBs (multivariable-adjusted odds ratio 2.59, 95% confidence interval [CI] 1.01-6.65) but not with deep CMBs. Concurrently having ≥2 retinal microvascular signs was associated with a 3-fold (95% CI 1.73-5.20) increased likelihood for deep CMBs but not exclusively lobar CMBs.

CONCLUSIONS

Retinal microvascular signs and pure geographic atrophy may be associated with deep and exclusively lobar CMBs, respectively, in older people. These results have implications for further research to define the role of small vessel disease in cognitive impairment.

Association between PEDF gene polymorphisms and the risk of age-related macular degeneration

OBJECTIVE

Pigment epithelium-derived factor (PEDF) strongly inhibits angiogenesis, and plays an important role in retinoblastoma cells. In this study we detect the association of PEDF gene polymorphisms (rs1136287 and rs12150053) and age-related macular degeneration (AMD) risk.

METHODS

This is a case-control study including 118 AMD patients and 121 healthy controls. PEDF gene polymorphisms were genotyped by TaqMan method. Hardy-Weinberg equilibrium (HWE) was used to detect the representativeness of the cases and controls. Differences of genotype and allele distributions of PEDF polymorphisms were calculated by Chi-square test. Odds ratios (ORs) and corresponding 95% confidence intervals (95% CIs) were used to present the relative risk of AMD.

RESULTS

Genotype and allele distributions in controls were in accordance with HWE. Genotype and allele distributions of rs1136287 had no significant association with the susceptibility of AMD under five contrast models (P<0.05). CC genotype and C allele of rs12150053 were higher in cases than that in controls, and rs12150053 was obviously related to the risk of AMD under T vs. C model (P=0.044, OR=1.499, 95% CI=1.009-2.226).

CONCLUSION

In this study, there was no obvious association between PEDF gene rs1136287 polymorphism and AMD susceptibility, and rs12150053T might act as a susceptible allele in the occurrence of AMD.

[Epidemiology of age-related macular degeneration]

Age-related macular degeneration (AMD) is the main cause of blindness in industrialized societies. Population-based epidemiological investigations generate important data on prevalence, incidence, risk factors, and future trends. This review summarizes the most important epidemiological studies on AMD with a focus on their transferability to Germany including existing evidence for the main risk factors for AMD development and progression. Future tasks, such as the standardization of grading systems and the use of recent retinal imaging technology in epidemiological studies are discussed. In Germany, epidemiological data on AMD are scarce. However, the need for epidemiological research in ophthalmology is currently being addressed by several recently started population-based studies.

Features of Age-Related Macular Degeneration in the General Adults and Their Dependency on Age, Sex, and Smoking: Results from the German KORA Study

Age-related macular degeneration (AMD) is a vision impairing disease of the central retina characterized by early and late forms in individuals older than 50 years of age. However, there is little knowledge to what extent also younger adults are affected. We have thus set out to estimate the prevalence of early AMD features and late AMD in a general adult population by acquiring color fundus images in 2,840 individuals aged 25 to 74 years of the Cooperative Health Research in the Region of Augsburg project (KORA) in South Germany. Among the 2,546 participants with gradable images for each eye, 10.9% (n = 277) had early AMD features (applying the 9-step Age-Related Eye Disease Study Severity Scale), 0.2% (n = 6) had late AMD. Prevalence increased with age, reaching 26.3% for early AMD features and 1.9% for late AMD at the age 70+. However, signs of early AMD were found in subjects as young as 25 years, with the risk for early AMD features increasing linearly by years of age in men, and, less consistent with a linear increase, in women. Risk for early AMD features increased linearly by pack years of smoking in men, not in women, nor was there any association with other lifestyle or metabolic factors. By providing much sought-after prevalence estimates for AMD from Central Europe, our data underscores a substantial proportion of the adult population with signs of early AMD, including individuals younger than 50 years. This supports the notion that early AMD features in the young might be under-acknowledged.

Ex Vivo Confocal Spectroscopy of Autofluorescence in Age-Related Macular Degeneration

Purpose

We investigated the autofluorescence (AF) signature of the microscopic features of retina with age-related macular degeneration (AMD) using 488 nm excitation.

Methods

The globes of four donors with AMD and four age-matched controls were embedded in paraffin and sectioned through the macula. Sections were excited using a 488 nm argon laser, and the AF emission was captured using a laser scanning confocal microscope (496–610 nm, 6 nm resolution). The data cubes were then analyzed to compare peak emission spectra between the AMD and the controls. Microscopic features, including individual lipofuscin and melanolipofuscin granules, Bruch’s Membrane, as well macroscopic features, were considered.

Results

Overall, the AMD eyes showed a trend of blue-shifted emission peaks compared with the controls. These differences were statistically significant when considering the emission of the combined RPE/Bruch’s Membrane across all the tissue cross-sections (p = 0.02).

Conclusions

The AF signatures of ex vivo AMD RPE/BrM show blue-shifted emission spectra (488 nm excitation) compared with the control tissue. The magnitude of these differences is small (~4 nm) and highlights the potential challenges of detecting these subtle spectral differences in vivo.

Age-related macular degeneration in Portugal: prevalence and risk factors in a coastal and an inland town. The Coimbra Eye Study - Report 2

PURPOSE

To determine the age- and sex-specific prevalence of early and late age-related macular degeneration (AMD) in two Portuguese population-based samples and to identify its risk factors.

POPULATION

A population of 6023 adults aged ≥55 years was recruited from two Portuguese primary healthcare units in the central region of Portugal - one from a coastal (n = 3000) and another from an inland town (n = 3023).

METHODS

Cross-sectional population-based study. Participants were enrolled in the two locations between August 2009 and October 2013. Responders underwent standardized interviews and ophthalmologic examination, including digital fundus imaging. All fundus photographs were graded according to an International Classification and Grading System. The main outcome measures consisted of age- and sex-adjusted prevalence of early and late AMD. Potential epidemiologic risk factors were also evaluated using logistic regression analysis.

RESULTS

Of the 6023 subjects enrolled, 5996 had gradable fundus images and were included in the analysis. The crude prevalence of early and late AMD was 6.99 and 0.67%, respectively, for the coastal town and 15.39 and 1.29% for the inland town. Age- and sex-adjusted prevalence of any AMD for the Portuguese population was 12.48% (95% CI: 11.61-13.33) with late AMD accounting for 1.16% (95% CI: 0.85-1.46). Neovascular AMD (NV-AMD) and geographic atrophy (GA) accounted for 0.55% (95% CI: 0.36-0.75) and 0.61% (95% CI: 0.37-0.84) of individuals, respectively. After adjusting for possible confounding factors, prevalence of early and late AMD increased with increasing age (OR = 1.35; 95% CI: 1.23-1.49 for early and OR = 3.01; 95% CI: 2.22-4.08 for late AMD, per each decade of age increase, p < 0.001). After adjustment for age, sex, family history, smoking history, hypertension, diabetes and BMI, subjects from the inland town presented a significantly higher OR of early and late AMD than subjects from the coastal town (OR = 2.57, 95% CI: 2.12-3.12, p < 0.001 for early and OR = 2.06, 95% CI: 1.07-3.95, p = 0.029 for late AMD).

CONCLUSIONS

The prevalence of early and late AMD in this Portuguese population was similar to other large-scale population-based cohorts. After controlling for confounders, age and study site of inclusion were significant independent predictors for both early and late forms of the disease. Further analysis will be needed to completely unravel the underlying reasons for this difference regarding geographic location.

A Revised Hemodynamic Theory of Age-Related Macular Degeneration

Age-related macular degeneration (AMD) afflicts one out of every 40 individuals worldwide, causing irreversible central blindness in millions. The transformation of various tissue layers within the macula in the retina has led to competing conceptual models of the molecular pathways, cell types, and tissues responsible for the onset and progression of AMD. A model that has persisted for over 6 decades is the hemodynamic, or vascular theory of AMD progression, which states that vascular dysfunction of the choroid underlies AMD pathogenesis. Here, we re-evaluate this hypothesis in light of recent advances on molecular, anatomic, and hemodynamic changes underlying choroidal dysfunction in AMD. We propose an updated, detailed model of hemodynamic dysfunction as a mechanism of AMD development and progression.

Hearing in older adults with exfoliation syndrome/exfoliation glaucoma or primary open-angle glaucoma

PURPOSE

To determine whether adults, aged 66-96 years, with exfoliation syndrome (XFS)/exfoliation glaucoma (XFG), or primary open-angle glaucoma (POAG) have poorer hearing than controls of similar age.

METHODS

Case (XFS/XFG and POAG) and control status was diagnosed in the Reykjavik Glaucoma Studies (RGS) using slit-lamp examination, visual field testing and optic disc photographs; the RGS data were merged with the Age, Gene/Environment Susceptibility-Reykjavik Study that collected hearing data using air-conduction, pure-tone thresholds obtained at 0.5, 1, 2, 3, 4, 6 and 8 kHz categorized by better ear and worse ear, based on pure-tone averages (PTAs) calculated separately for low and middle frequencies (PTA512 - mean of thresholds at 0.5, 1 and 2 kHz) and high frequencies (PTA3468 - mean of thresholds at 3, 4, 6 and 8 kHz). Multivariable linear regression was used to test for differences in PTAs between cases and controls.

RESULTS

The mean age for 158 XFS/XFG cases (30.4% male) was 77.4 years, 95 POAG cases (35.8% male) was 77.9 years, and 123 controls (46.3% male) was 76.8 years. Using multivariable linear regression analysis, there were no consistent, statistically significant differences in PTAs between the two case groups and controls in either the low- or high-frequency range, even when stratified by age group.

CONCLUSION

Among the older individuals examined in this study hearing loss is highly prevalent and strongly associated with male gender and increasing age. As we did not find consistent statistically significant difference in hearing between cases and controls the diagnosis of XFS/XFG or POAG does not as such routinely call for audiological evaluation.

Geo-Epidemiology of Age-Related Macular Degeneration: New Clues Into the Pathogenesis

PURPOSE

To evaluate the demographic, geographic, and race-related variables that account for geographic variability in prevalence rates of age-related macular degeneration (AMD).

DESIGN

Systematic review, meta-regression, and decision-tree analysis.

METHODS

A systematic literature review of PubMed, Medline, Web of Science, and Embase databases identified population-based studies on the prevalence of AMD published before May 2014. Only population-based studies that took place in a spatially explicit geographic area that could be geolocalized, and used retinal photographs and standardized grading classifications, were included. Latitude and longitude data (geolocalization) and the mean annual insolation for the area where survey took place were obtained. Age-standardized prevalence rates across studies were estimated using the direct standardization method. Correlations between the prevalence of AMD and longitude and latitude were obtained by regression analysis. A hierarchical Bayesian meta-regression approach was used to assess the association between the prevalence of AMD and other relevant factors. We further investigated the interplay between location and these factors on the prevalence of AMD using regression based on conditional-inference decision trees.

RESULTS

We observed significant inverse correlations between latitude or longitude, and crude or age-standardized prevalence rates, of early and late AMD (P < .001). Metaregression analysis showed that insolation, latitude, longitude, age, and race have a significant effect on the prevalence rates of early and late AMD (P < .001). Decision-tree analysis identified that the most important predictive variable was race for early AMD (P = .002) and insolation for late AMD (P = .001).

CONCLUSIONS

Geographic position and insolation are key factors in the prevalence of AMD.

CX3CR1 polymorphisms and the risk of age-related macular degeneration

BACKGROUND

Age-related macular degeneration (AMD), a most common eye disease, can lead to irreversible visual impairment. Age, genetic and environmental factors have been implicated in AMD. Chemokine (C-X3-C motif) receptor 1 (CX3CR1) gene polymorphisms could influence the susceptibility of AMD.

METHODS

We tested the association between AMD and single nocleotide polymorphisms (SNPs) of CX3CR1 gene (rs3732378 and rs3732379) in 102 cases and 115 controls from China. Genotypes were determined by MassArray genotyping assay method. Association between CX3CR1 gene polymorphisms and AMD were examined by χ(2) test and logistic regression.

RESULTS

Genotype distribution of CX3CR1 gene polymorphisms were in accordance with HWE examination. No obvious differences were observed in the genotypes of rs3732378 polymorphism between case and control groups (P>0.05), but A allele of it could increase the risk of AMD (P=0.025, OR=2.391, 95% CI=1.092-5.237). Both TT genotype and T allele of rs3732379 were significantly associated with the susceptibility of AMD (P=8.663, OR=8.663, 95% CI=1.044-71.874; P=0.021, OR=2.076, 95% CI=1.104-3.903). Age, gender and smoking status were used as common confounders to adjust the association between CX3CR1 gene polymorphism and AMD risk. Then we found that rs3732378 had no obvious association with AMD susceptibility. TT genotype of rs3732379 related to the occurrence of AMD, but the association was not significant (P=0.050, OR=8.274, 95% CI=1.002-69.963). T allele of rs3732379 might increase the susceptibility of AMD (P=0.029, OR=2.033, 95% CI=1.077-3.838).

CONCLUSION

T allele of rs3732379 might have a positive association with the susceptibility of AMD.

Correlation between the interactions of ABCA4 polymorphisms and smoking with the susceptibility to age-related macular degeneration

OBJECTIVE

Our study was aimed to analyze the relationship between retina-specific ATP-binding cassette, sub-family A, member 4 (ABCA4) gene polymorphisms and gene-environment interactions with age-related macular degeneration (AMD) susceptibility.

METHODS

98 AMD patients and 110 healthy controls, matched in age and sex, were enrolled in this study. ABCA4 polymorphisms (2633C>A, 5646G>A and 6389T>A) were determined by direct sequencing. Differences of genotype and allele distributions were analyzed by χ(2) test. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were adopted to represent the relative risk of AMD. Gene-environment interactions were analyzed using crossover analysis.

RESULTS

2633C>A polymorphism had no obvious correlation with AMD risk. Genotype AA and allele A in 5646G>A polymorphism significantly increased the risk of AMD (OR=4.753, 95% CI=1.249-18.085; OR=1.944, 95% CI=1.209-3.126). 6389T>A polymorphism AA genotype had no significant correlation with AMD risk, but the A allele distinctly enhanced the AMD risk (OR=1.681, 95% CI=1.071-2.639). Afterwards, we analyzed the interactions between ABCA4 polymorphisms and smoking on AMD. Smoking had interactions with all of 2633C>A (CC+CA), 5646G>A and 6389T>A polymorphisms, and the interactions were significantly correlated with AMD.

CONCLUSIONS

2633C>A (CC+CA) genotype, 5646G>A and 6389T>A polymorphisms of ABCA4 gene and smoking are susceptible factors for AMD, and the interactions of ABCA4 polymorphisms with smoking increased the risk of AMD.

The genetics of age-related macular degeneration (AMD)--Novel targets for designing treatment options?

Age-related macular degeneration (AMD) is a progressive disease of the central retina and the main cause of legal blindness in industrialized countries. Risk to develop the disease is conferred by both individual as well as genetic factors with the latter being increasingly deciphered over the last decade. Therapeutically, striking advances have been made for the treatment of the neovascular form of late stage AMD while for the late stage atrophic form of the disease, which accounts for almost half of the visually impaired, there is currently no effective therapy on the market. This review highlights our current knowledge on the genetic architecture of early and late stage AMD and explores its potential for the discovery of novel, target-guided treatment options. We reflect on current clinical and experimental therapies for all forms of AMD and specifically note a persisting lack of efficacy for treatment in atrophic AMD. We further explore the current insight in AMD-associated genes and pathways and critically question whether this knowledge is suited to design novel treatment options. Specifically, we point out that known genetic factors associated with AMD govern the risk to develop disease and thus may not play a role in its severity or progression. Treatments based on such knowledge appear appropriate rather for prevention than treatment of manifest disease. As a consequence, future research in AMD needs to be greatly focused on approaches relevant to the patients and their medical needs.

Lens status influences the association between CFH polymorphisms and age-related macular degeneration: findings from two population-based studies in Singapore

Aims

To determine the differential effects of genetic polymorphism in CFH and ARMS2 on risk of age-related macular degeneration (AMD) between phakic vs. pseudophakic/aphakic eyes.

Methods

9,529 eyes of 4,918 participants from the Singapore Malay Eye Study and Singapore Indian Eye Study were analyzed. Participants had detailed eye examinations, including slit-lamp examinations and dilated fundus photography. AMD grading was performed according to the Wisconsin age-related maculopathy grading system. Lens status was defined. Single nucleotide polymorphisms (SNPs) rs10801555 (Y402H) within CFH and rs3750847 in ARMS2 were assessed. The main outcome measure was early AMD or any AMD.

Results

No significant associations between the CFH Y402H genotypes and early AMD were found in phakic individuals. In contrast, among pseudophakic/aphakic individuals, the CFH Y402H risk genotypes were significantly associated with higher odds of early AMD, with an OR of 1.57 (95% CI: 1.07–2.29) for GA genotype and 2.40 (95% CI: 1.25–4.61) for AA genotype, compared to those with GG genotype. There was significant interaction between pseudophakic/aphakic status and CFH Y402H variant on risk of early AMD (p = 0.037), adjusting for age, gender, and the first 5 genetic principal components. No significant interaction was found between lens status and ARMS2 rs3750847.

Conclusions

CFH genetic polymorphism and pseudophakic/aphakic status may have a potential synergistic effect on early AMD, suggesting roles for the complement system and related pathways in the pathogenesis of AMD in eyes after cataract surgery.

Prevalence of Age-Related Macular Degeneration in Portugal: The Coimbra Eye Study - Report 1

PURPOSE

To evaluate the age- and gender-specific prevalence of early and late age-related macular degeneration (AMD) in a Portuguese population-based sample.

METHODS

All patients aged ≥55 years of a Portuguese primary health-care unit were recruited for a cross-sectional population-based study. Responders underwent complete ophthalmological examination and digital fundus imaging. Early and late AMD was defined according to the International Age-Related Macular Epidemiological Study Group Classification, and the adopted staging for AMD was the same as that used in the Rotterdam study. The age- and gender-adjusted prevalence of early and late forms of AMD was calculated.

RESULTS

Of the 4,370 eligible subjects, 3,000 underwent study procedures (68.6% response rate) and 2,975 were included in the analysis; they had a mean age of 68.9 ± 8.6 years. The overall prevalence of early and late AMD was 15.53% (95% CI 14.25-16.88) and 0.67% (95% CI 0.41-1.04), respectively. Neovascular AMD (NV-AMD) and geographic atrophy (GA) accounted for 0.44% (95% CI 0.23-0.75) and 0.27% (95% CI 0.12-0.53) of individuals, respectively. The highest prevalence of advanced AMD was among those aged ≥75 years (1.13% for NV-AMD; 0.63% for GA).

CONCLUSIONS

To our knowledge, this is the first AMD epidemiological study in a Portuguese population. The early forms of the disease had a similar prevalence to that of other large-scale population-based cohorts, but late AMD was less frequent than previously reported.

Age-related macular degeneration and mortality in community-dwelling elders: the age, gene/environment susceptibility Reykjavik study

OBJECTIVE

To investigate the association between age-related macular degeneration (AMD) and mortality in older persons.

DESIGN

Population-based prospective cohort study.

PARTICIPANTS

Participants 67 to 96 years of age (43.1% male) enrolled between 2002 and 2006 in the Age, Gene/Environment Susceptibility-Reykjavik Study.

METHODS

Retinal photographs of the macula were acquired digitally and evaluated for the presence of AMD lesions using the Wisconsin Age-Related Maculopathy grading scheme. Mortality was assessed prospectively through 2013 with cause of death available through 2009. The association between AMD and death, resulting from any cause and specifically cardiovascular disease (CVD), was examined using Cox proportional hazards regression with age as the time scale, adjusted for significant risk factors and comorbid conditions. To address a violation in the proportional hazards assumption, analyses were stratified into 2 groups based on the mean age at death (83 years).

MAIN OUTCOME MEASURES

Mortality resulting from all causes and CVD.

RESULTS

Among 4910 participants, after a median follow-up of 8.6 years, 1742 died (35.5%), of whom 614 (35.2%) had signs of AMD at baseline. Cardiovascular disease was the cause of death for 357 people who died before the end of 2009, of whom 144 (40%) had AMD (101 with early disease and 43 with late disease). After considering covariates, including comorbid conditions, having early AMD at any age or having late AMD in individuals younger than 83 years (n = 4179) were not associated with all-cause or CVD mortality. In individuals 83 years of age and older (n = 731), late AMD was associated significantly with increased risk of all-cause mortality (hazard ratio [HR], 1.76; 95% confidence interval [CI], 1.20-2.57) and CVD-related mortality (HR, 2.37; 95% CI, 1.41-3.98). In addition to having AMD, older individuals who died were more likely to be male and to have low body mass index, impaired cognition, and microalbuminuria.

CONCLUSIONS

Competing risk factors and concomitant conditions are important in determining mortality risk resulting from AMD. Individuals with early AMD are not more likely to die than peers of comparable age. Late AMD becomes a predictor of mortality by the mid-octogenarian years.

Population-based age group specific annual incidence rates of symptomatic age-related macular degeneration

Purpose

To study the population-based annual incidence rates of exudative, dry and all cases of symptomatic age-related macular degeneration (AMD) in different age and sex groups.

Methods.

This is a one year, prospective, population-based study on all consecutive new patients with AMD in the hospital district of Central Finland. The diagnosis was confirmed in all patients with slit lamp biomicroscopy, optical coherence tomography (OCT) using a Spectralis HRA + OCT device, and the Heidelberg Eye Explorer 1.6.2.0 program. Fluorescein angiograms were taken when needed.

Results.

The population-based annual incidence rates of all cases of symptomatic AMD increased from 0.03% (95% CI, 0.01-0.05%) in the age group 50-59 years to 0.82% (95% CI, 0.55-1.09%) in the age group 85-89 years and were 0.2% (95% CI, 0.17-0.24%) in exudative, 0.11% (95% CI, 0.09-0.14%) in dry, and 0.32% (95% CI, 0.28-0.36%) in all cases of AMD in the age group 60 years and older. During the next 20 years in Central Finland the population-based annual incidence rates can be estimated to increase to 0.27% (95% CI, 0.24-0.30%) in exudative, to 0.13% (95% CI, 0.11-0.15%) in dry, and to 0.41% (95% CI, 0.37-0.45%) in all cases of AMD in the age group 60 years and older. The population-based annual incidence of AMD did not show statistically significant differences between males and females (p>0.1).

Conclusion:

The population-based age-group specific annual incidence rates of symptomatic AMD of this study may help to plan health care provision for patients of AMD.

Adipose tissue, muscle, and function: potential mediators of associations between body weight and mortality in older adults with type 2 diabetes

OBJECTIVE

Studies in type 2 diabetes report both increased mortality for normal weight and no evidence of an obesity paradox. We aimed to examine whether adipose tissue, muscle size, and physical function, which are known to vary by weight, mediate associations between BMI and mortality.

RESEARCH DESIGN AND METHODS

The AGES-Reykjavik cohort comprised participants aged 66-96 years with diabetes defined by fasting glucose, medications, or self-report. BMI was determined from measured height and weight and classified as normal (18.5-24.9 kg/m(2), n = 117), overweight (25.0-29.9 kg/m(2), n = 293, referent group) or obese (≥30.0 kg/m(2), n = 227). Thigh muscle area and intermuscular, visceral, and subcutaneous adipose tissues were assessed with computed tomography. Function was assessed from gait speed and knee extensor strength. Hazard ratios (HRs) and 95% CIs were estimated by Cox proportional hazards regression adjusted for demographics and diabetes-related risk factors.

RESULTS

The median follow-up was 6.66 years, and there were 85, 59, and 44 deaths among normal weight, overweight, and obese participants, respectively. There was no mortality risk for obese participants and an increased risk among normal weight compared with overweight participants (HR 1.72 [95% CI 1.12-2.64]). Associations remained with adjustment for adipose tissues and knee extensor strength; however, mortality risk for normal weight was attenuated following adjustment for thigh muscle (HR 1.36 [95% CI 0.87-2.11]) and gait speed (HR 1.44 [95% CI 0.91-2.27]). Linear regression confirmed with bootstrapping indicated that thigh muscle size mediated 46% of the relationship between normal weight and mortality.

CONCLUSIONS

Normal weight participants had elevated mortality risk compared with overweight participants. This paradoxical association was mediated in part by muscle size.

Is renal function associated with early age-related macular degeneration?

PURPOSE

Age-related macular degeneration (AMD) and chronic kidney disease both involve immune dysregulation and may share underlying pathophysiologic changes to systemic homeostasis. Hence, we aim to evaluate associations between impaired kidney function and early AMD, in a search for urinary biomarkers for AMD.

METHODS

A population-based, cross-sectional analysis of persons aged 45 to 84 years was conducted with renal function measured using serum creatinine and cystatin C levels and the estimated glomerular filtration rate (eGFR) calculated. Age-related macular degeneration status was ascertained from retinal photographs.

RESULTS

Of 5874 participants, 221 had early AMD. High serum cystatin C and low eGFR (≤60 ml/min/1.73 m) were not associated with early AMD in our multivariate analyses. Among normotensive persons, however, highest versus other deciles of cystatin C were associated with an increased prevalence of early AMD (odds ratio, 1.80; 95% confidence interval, 1.00 to 3.23).

CONCLUSIONS

Results could not confirm an association between kidney function and early AMD. The borderline association between cystatin C and early AMD in normotensive persons require further verification.

A circulating microrna profile is associated with late-stage neovascular age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of severe vision impairment in Western populations over 55 years. A growing number of gene variants have been identified which are strongly associated with an altered risk to develop AMD. Nevertheless, gene-based biomarkers which could be dysregulated at defined stages of AMD may point toward key processes in disease mechanism and thus may support efforts to design novel treatment regimens for this blinding disorder. Circulating microRNAs (cmiRNAs) which are carried by nanosized exosomes or microvesicles in blood plasma or serum, have been recognized as valuable indicators for various age-related diseases. We therefore aimed to elucidate the role of cmiRNAs in AMD by genome-wide miRNA expression profiling and replication analyses in 147 controls and 129 neovascular AMD patients. We identified three microRNAs differentially secreted in neovascular (NV) AMD (hsa-mir-301-3p, p_corrected = 5.6*10⁻⁵, hsa-mir-361-5p, p_corrected = 8.0*10⁻⁴ and hsa-mir-424-5p, p_corrected = 9.6*10⁻³). A combined profile of the three miRNAs revealed an area under the curve (AUC) value of 0.727 and was highly associated with NV AMD (p = 1.2*10⁻⁸). To evaluate subtype-specificity, an additional 59 AMD cases with pure unilateral or bilateral geographic atrophy (GA) were analyzed for microRNAs hsa-mir-301-3p, hsa-mir-361-5p, and hsa-mir-424-5p. While we found no significant differences between GA AMD and controls neither individually nor for a combined microRNAs profile, hsa-mir-424-5p levels remained significantly higher in GA AMD when compared to NV (p_corrected<0.005). Pathway enrichment analysis on genes predicted to be regulated by microRNAs hsa-mir-301-3p, hsa-mir-361-5p, and hsa-mir-424-5p, suggests canonical TGFβ, mTOR and related pathways to be involved in NV AMD. In addition, knockdown of hsa-mir-361-5p resulted in increased neovascularization in an invitro angiogenesis assay.

Five-year incidence, progression, and risk factors for age-related macular degeneration: the age, gene/environment susceptibility study

OBJECTIVE

To investigate the incidence and progression of age-related macular degeneration (AMD) and associated risk factors.

DESIGN

Population-based, prospective, cohort study.

PARTICIPANTS

We included 2868 participants from the Age Gene/Environment Susceptibility-Reykjavik Study with retinal data at baseline and 5-year follow-up.

METHODS

Digital macular photographs were graded for presence of AMD. Participants completed a questionnaire and extensive clinical battery. Biomarkers were assessed. Risk factors for AMD were analyzed using multivariate regression analysis with odds ratios (ORs) and 95% CIs.

MAIN OUTCOME MEASURES

We assessed AMD, defined as early or late.

RESULTS

Among 2196 participants free of AMD at baseline, 14.9% developed incident AMD. In multivariate models, incident AMD was significantly associated with age (OR per year, 1.14; 95% CI, 1.11-1.17), current smoking (OR, 2.07; 95% CI, 1.38-3.11), former smoking (OR, 1.36; 95% CI, 1.04-1.79), plasma high-density lipoprotein (HDL) cholesterol level (OR, 1.62 per mmol/L; 95% CI, 1.19-2.22), and body mass index (BMI; OR, 1.04 per kg/m(2); 95% CI, 1.01-1.07). Among 563 participants with early AMD at baseline, 22.7% progressed to late AMD (11.0% pure geographic atrophy [GA] and 11.7% exudative AMD). On multivariate analyses, age was significantly associated with progression to GA (OR 1.14; 95% CI, 1.07-1.21) and exudative AMD (OR, 1.08; 95% CI, 1.01-1.14). Adjusting for age, female sex was associated with exudative AMD (OR, 2.10; 95% CI, 1.10-3.98) and plasma HDL cholesterol with GA (OR, 2.03 per mmol/L; 95% CI, 1.02-4.05).

CONCLUSIONS

By age 85, 57.4% of participants had signs of AMD. Age, smoking, plasma HDL cholesterol, BMI, and female sex are associated with AMD. Elevated HDL cholesterol is associated with GA development.

Correlation of platelet activating factor and age-related macular degeneration

OBJECTIVE

To investigate the role of Platelet Activating Factor (PAF) in the pathogenesis and development of Age-Related Macular Degeneration (ARMD).

RESEARCH DESIGN AND METHODS

Fifty six patients with ARMD (24 patients with dry ARMD and 32 patients with wet ARMD) and 25 age-matched control participants underwent ophthalmological examination, including visual acuity measurement and evaluation of the retina. The participants were classified into three groups according to their retinal status, based on indirect fundoscopy, Optical Coherence Tomography and fluorescein angiography findings. In order to evaluate the concentrations of PAF in serum, blood samples were collected from all participants and were analyzed with ELISA technique.

RESULTS

The concentrations of PAF differed significantly according to macular lesions and were found to be lower in patients with ARMD than control participants.

CONCLUSIONS

PAF levels are decreased along with the severity of ARMD. Understanding the role of PAF in pathogenesis of ARMD could be the impetus for the development of new therapies field of treatment of ARMD or even other retinal diseases.

Prevalence and risk factors for age-related macular degeneration in the elderly Chinese population in south-western Taiwan: the Puzih eye study

AIM

This study aimed to ascertain the prevalence of and the risk factors associated with early and late age-related macular degeneration (AMD) among Chinese individuals aged ≥65 years residing in Puzih, Taiwan.

METHODS

This population-based cross-sectional study graded digital colour photographs of the ocular fundus of 673 individuals using the Wisconsin Age-Related Maculopathy Grading System. We compared the characteristics of individuals with early and late AMD using χ(2)-analyses and described risk factors for early and late AMD using odds ratios and 95% confidence intervals.

RESULTS

Individuals with late AMD were significantly older and more likely to have hypertension. Further, their sunlight exposure time was longer than that of those with early AMD, only drusen, or no AMD lesions (P<0.01). A history of hyperlipidaemia for >10 years was a significant risk factor for early AMD, while old age, hypertension for >10 years, and exposure to sunlight for >8 h per day were associated with late AMD.

CONCLUSIONS

The prevalence rate of early AMD in the present study was 15.0%, which is similar to that reported for Caucasians and Japanese included in the European Eye Study and the Hisayama Study, respectively. The late AMD prevalence rate of 7.3% found among our study participants was comparable to that reported by the Greenland Inuit Eye Study and Reykjavik Study, but considerably lower than that reported for Caucasians, indicating that late AMD might be less prevalent among Asians than Caucasians.

Cholesterol in the retina: the best is yet to come

Historically understudied, cholesterol in the retina is receiving more attention now because of genetic studies showing that several cholesterol-related genes are risk factors for age-related macular degeneration (AMD) and because of eye pathology studies showing high cholesterol content of drusen, aging Bruch's membrane, and newly found subretinal lesions. The challenge before us is determining how the cholesterol-AMD link is realized. Meeting this challenge will require an excellent understanding these genes' roles in retinal physiology and how chorioretinal cholesterol is maintained. In the first half of this review, we will succinctly summarize physico-chemical properties of cholesterol, its distribution in the human body, general principles of maintenance and metabolism, and differences in cholesterol handling in human and mouse that impact on experimental approaches. This information will provide a backdrop to the second part of the review focusing on unique aspects of chorioretinal cholesterol homeostasis, aging in Bruch's membrane, cholesterol in AMD lesions, a model for lesion biogenesis, a model for macular vulnerability based on vascular biology, and alignment of AMD-related genes and pathobiology using cholesterol and an atherosclerosis-like progression as unifying features. We conclude with recommendations for the most important research steps we can take towards delineating the cholesterol-AMD link.