Cardiovascular Risk Factors and the Long-term Incidence of Age-Related Macular Degeneration

Circulating Anti-Endothelial Cell Antibodies in Patients with Geographic Atrophy Related to Dry Age-Related Macular Degeneration

Background and Objectives: Age-related macular degeneration (AMD) is one of the leading causes of central vision loss among elderly patients, and its dry form accounts for the majority of cases. Although several causes and mechanisms for the development and progression of AMD have previously been identified, the pathogenesis of this complex disease is still not entirely understood. As inflammation and immune system involvement are strongly suggested to play a central role in promoting the degenerative process and stimulating the onset of complications, we aimed to analyze the frequency of serum anti-retinal (ARAs) and anti-endothelial cell antibodies (AECAs) in patients with dry AMD and to determine their relationship with the clinical features of the disease, notably the area of geographic atrophy (GA). Materials and Methods: This study included 41 patients with advanced-stage dry AMD and 50 healthy controls without AMD, matched for gender and age. ARAs were detected by indirect immunofluorescence using monkey retina as an antigen substrate, and the presence of AECAs was determined using cultivated human umbilical vein endothelial cells and primate skeletal muscle. Results: ARAs were detected in 36 (87.8%) AMD patients (titers ranged from 1:20 to 1:320) and in 16 (39.0%) (titers ranged from 1:10 to 1:40) controls (p = 0.0000). Twenty of the forty-one patients (48.8%) were positive for AECAs, while in the control group, AECAs were present only in five sera (10.0%). The titers of AECAs in AMD patients ranged from 1:100 to 1:1000, and in the control group, the AECA titers were 1:100 (p = 0.0001). There were no significant correlations between the presence of AECAs and disease activity. Conclusions: This study demonstrates a higher prevalence of circulating AECAs in patients with dry AMD; however, no correlation was found between the serum levels of these autoantibodies and the area of GA.

Hypertension facilitates age-related diseases. ~ Is hypertension associated with a wide variety of diseases?~

Hypertension, a disease whose prevalence increases with age, induces pathological conditions of ischemic vascular disorders such as cerebral infarction and myocardial infarction due to accelerated arteriosclerosis and circulatory insufficiency of small arteries and sometimes causes hemorrhagic conditions such as cerebral hemorrhage and ruptured aortic aneurysm. On the other hand, as it is said that aging starts with the blood vessels, impaired blood flow associated with vascular aging is the basis for the development of many pathological conditions, and ischemic changes in target organs associated with vascular disorders result in tissue dysfunction and degeneration, inducing organ hypofunction and dysfunction. Therefore, we hypothesized that hypertension is associated with all age-related vascular diseases, and attempted to review the relationship between hypertension and diseases for which a relationship has not been previously well reported. Following our review, we hope that a collaborative effort to unravel age-related diseases from the perspective of hypertension will be undertaken together with experts in various specialties regarding the relationship of hypertension to all pathological conditions.

Association of age at diagnosis of diabetes with subsequent risk of age-related ocular diseases and vision acuity

BACKGROUND

The importance of age on the development of ocular conditions has been reported by numerous studies. Diabetes may have different associations with different stages of ocular conditions, and the duration of diabetes may affect the development of diabetic eye disease. While there is a dose-response relationship between the age at diagnosis of diabetes and the risk of cardiovascular disease and mortality, whether the age at diagnosis of diabetes is associated with incident ocular conditions remains to be explored. It is unclear which types of diabetes are more predictive of ocular conditions.

AIM

To examine associations between the age of diabetes diagnosis and the incidence of cataract, glaucoma, age-related macular degeneration (AMD), and vision acuity.

METHODS

Our analysis was using the UK Biobank. The cohort included 8709 diabetic participants and 17418 controls for ocular condition analysis, and 6689 diabetic participants and 13378 controls for vision analysis. Ocular diseases were identified using inpatient records until January 2021. Vision acuity was assessed using a chart.

RESULTS

During a median follow-up of 11.0 years, 3874, 665, and 616 new cases of cataract, glaucoma, and AMD, respectively, were identified. A stronger association between diabetes and incident ocular conditions was observed where diabetes was diagnosed at a younger age. Individuals with type 2 diabetes (T2D) diagnosed at < 45 years [HR (95%CI): 2.71 (1.49-4.93)], 45-49 years [2.57 (1.17-5.65)], 50-54 years [1.85 (1.13-3.04)], or 50-59 years of age [1.53 (1.00-2.34)] had a higher risk of AMD independent of glycated haemoglobin. T2D diagnosed < 45 years [HR (95%CI): 2.18 (1.71-2.79)], 45-49 years [1.54 (1.19-2.01)], 50-54 years [1.60 (1.31-1.96)], or 55-59 years of age [1.21 (1.02-1.43)] was associated with an increased cataract risk. T2D diagnosed < 45 years of age only was associated with an increased risk of glaucoma [HR (95%CI): 1.76 (1.00-3.12)]. HRs (95%CIs) for AMD, cataract, and glaucoma associated with type 1 diabetes (T1D) were 4.12 (1.99-8.53), 2.95 (2.17-4.02), and 2.40 (1.09-5.31), respectively. In multivariable-adjusted analysis, individuals with T2D diagnosed < 45 years of age [β 95%CI: 0.025 (0.009,0.040)] had a larger increase in LogMAR. The β (95%CI) for LogMAR associated with T1D was 0.044 (0.014, 0.073).

CONCLUSION

The younger age at the diagnosis of diabetes is associated with a larger relative risk of incident ocular diseases and greater vision loss.

Prevalence and Risk Factors of Age-Related Macular Degeneration in South Korea: Korea National Health and Nutrition Examination Survey

PURPOSE

To evaluate the prevalence and risk factors of age-related macular degeneration (AMD) in the Korean population.

METHODS

In this cross-sectional study based on the Korea National Health and Nutrition Examination Survey (2017-2020) data 13,737 participants aged ≥ 40 years with assessable fundus images were included. The prevalence and risk factors of AMD were evaluated. The prevalence of early AMD, geographic atrophy (GA), and neovascular AMD were also assessed. Logistic regression analyses were used to identify risk factors.

RESULTS

The prevalence (95% confidence interval [CI]) of AMD was 13.94% (13.15-14.72). The prevalence (95% CI) of early AMD, GA, and neovascular AMD was 13.07% (12.29-13.85), 0.26% (0.17-0.35), and 0.61% (0.47-0.75), respectively. The prevalence increased with age; it was 3.61%, 11.33%, 20.31%, 31.37%, and 33.98% in participants in their 40s, 50s, 60s, 70s, and ≥ 80 years, respectively. In multivariate analysis, AMD was positively associated with older age (p < 0.001; odds ratio [OR], 1.08; 95% CI, 1.07-1.09), male sex (p = 0.014; OR, 1.27; 95% CI, 1.05-1.53), and lower degree of education (p < 0.001; OR, 1.36 (for junior high school graduates); 95% CI, 1.12-1.65).

CONCLUSIONS

AMD was detected in approximately one-third of individuals aged ≥ 70 years, thus indicating that AMD is a common disease among older Koreans. Regular fundus examinations in populations with risk factors for AMD as well as education on methods to prevent or delay AMD progression, such as the Mediterranean diet, are necessary.

Retinal vessel diameters in intermediate age-related macular degeneration using en face optical coherence tomography

CLINICAL RELEVANCE

Clinical assessment of age-related macular degeneration (AMD) relies on biomarkers that do not necessarily reflect the contributions of vascular dysfunction. Validation of clinically accessible methods of measuring retinal vascular integrity could provide a more holistic understanding of AMD-related changes to facilitate appropriate care.

BACKGROUND

There is conflicting evidence if retinal vessel calibre is significantly altered in the early stages of AMD. This study examined the outer and inner diameters of first order retinal vessels in intermediate AMD eyes using en face optical coherence tomography (OCT).

METHODS

Retinal en face (6 × 6 mm) OCT images were examined in a single eye of participants with intermediate AMD (n = 46) versus normal macula (n = 43) for arterioles (all identifiable) and venules (40/46 and 39/43 identifiable). All participants were aged ≥50 years without diabetes mellitus, hypertension, or other systemic vascular disease.

RESULTS

Intra- and inter-grader agreement was good-to-excellent for all en face OCT measurements of arteriole and venule diameters (intraclass correlation coefficient = 0.87 to 0.99). Arteriolar outer diameters (82.3 ± 19.8 µm vs 73.8 ± 16.1 µm; p < 0.05) and inner diameters (35.1 ± 8.4 µm vs 31.5 ± 8.1 µm; p < 0.05) were significantly greater in AMD eyes compared to normal eyes. Venular inner diameter was significantly greater (43.1 ± 9.5 µm vs 39.2 ± 10.1 µm; p < 0.05), but outer diameter remained unchanged (p = 0.17) in AMD eyes compared to normal eyes.

CONCLUSION

Arteriolar dilation and altered venular inner diameter were observed in intermediate AMD eyes. These results support further investigation of vascular contributions to AMD in the early stages of disease, possibly using the en face OCT imaging modality.

Age-related macular degeneration and cardiovascular disease in US population: an observational study

BACKGROUND

As far as we know, age-related macular degeneration (AMD) has become one of the predominant causes of visual impairments. Previous studies have revealed that AMD and many cardiovascular diseases (CVDs) share the same pathologic and genotypic factors, making the connection between AMD and CVD a hot topic. However, the conclusions of the available studies on the relationship between them are somewhat divergent.

METHODS

We screened 5523 eligible participants from the National Health and Nutrition Examination Survey (NHANES) database from 2005 through 2008 for an observational clinical study design. Binary logistic regression modelling was used to estimate the relations between AMD and various CVDs with and without adjustment for demographics, health status, and behaviours related to health.

RESULTS

Binary logistic regression analyses showed that AMD was able to increase the risk of CVDs in patients both unadjusted and after adjusting for confounding variables.

CONCLUSIONS

Within this study, preventing the development of AMD might cut down the incidence of several CVDs, in particular, significantly lowering the stroke risk. These findings indicate that interventions to prevent AMD may also help to prevent CVDs. In general, late AMD has a more severe impact on the risk of CVDs compared with early AMD. These results could help clinical ophthalmology and cardiovascular medicine in their clinical education and interventions.

Epidemiology of geographic atrophy and its precursor features of intermediate age-related macular degeneration

Globally age-related macular degeneration (AMD) is a leading cause of blindness with a significant impact on quality of life. Geographic atrophy (GA) is the atrophic late form of AMD and its prevalence increases markedly with age with around 1 in 5 persons aged 85 and above having GA in at least one eye. Bilateral GA leads to severe visual impairment thus posing a significant burden on patients, careers and health providers. The incidence and prevalence of GA varies across different geographic regions, with the highest rates in those of European ancestry. Although heterogeneity in definitions of GA and reporting strategy can explain some of the discrepancies, the data overall are consistent in showing a lower prevalence in other ethnicities such as those of Asian heritage. This is at present unexplained but thought to be due to the existence of protective factors such as differences in eye pigmentation, diet, environmental exposures and genetic variability. This review covers key aspects of the prevalence and incidence of the ocular precursor features of GA (large drusen, pigmentary abnormalities and reticular pseudo-drusen), the late stage of GA and factors that have been known to be associated with modifying risk including systemic, demographic, environment, genetic and ocular. Understanding the global epidemiology scenario is crucial for the prevention of and management of patients with GA.

The role of TLR2 in exercise-induced immunomodulation in normal weight individuals

Toll-like receptors (TLRs) have been targeted for therapeutic drug development for several disorders, including cardiovascular diseases (CVD), and diabetes mellitus. Daily levels physical activity (PA) has been purported to influence the systemic circulation of cytokines, affecting the overall activation of TLRs and influencing the inflammatory milieu. Objective and self-reported daily PA was tracked in 69 normal-weight adults. Freedson's cut-offs categorized daily PA intensity into the 25th lowest, medium, and top percentiles. Monocytic TLR2 expression was quantified by flow cytometry in fresh whole blood. Cross-sectional associations between flow cytometry measured TLR2⁺ subsets and clinical biomarkers were evaluated. PA increased circulation of TLR2⁺ monocytes. TLR2 expression was adversely corelated with reduced diastolic blood pressure (DBP), triglyceride (TG), and matrix metallopeptidase 9 (MMP9) levels. However, regression analysis indicated that only TG levels were independently linked with TLR2⁺ subsets in circulation in active participants. Higher daily levels of physical activity are associated with improved cardiovascular blood markers and elevated circulatory monocytic TLR2⁺ subsets. These findings suggest that TLR2 may play a role in modulating CVD risk factors in individuals leading physically active lifestyles.

Age-Related Macular Degeneration With Visual Disability Is Associated With Cardiovascular Disease Risk in the Korean Nationwide Cohort

Background Age-related macular degeneration (AMD) is the leading cause of visual disability. AMD shares some risk factors with the pathogenesis of cardiovascular disease (CVD). However, previous studies examining the association between AMD and the risk of CVD provide conflicting results. Hence, we investigated the association between AMD, visual disability, and the risk of CVD. Methods and Results This is a nationwide cohort study using data from the Korean National Health Insurance System database (2009-2019) on subjects who underwent a national health screening program in 2009. A total of 3 789 963 subjects were categorized by the presence of AMD and visual disability. Visual disability was defined as a best-corrected visual acuity of ≤20/100 by validated documentation from a specialist physician. Cox regression hazard model was used to examine the hazard ratios (HRs) of CVD, including myocardial infarction and ischemic stroke, after adjusting for potential confounders. During a mean 9.77 years of follow-up, AMD was associated with a 5% higher risk of myocardial infarction (adjusted HR [aHR], 1.05 [95% CI, 1.01-1.10]) but not associated with increased risk of overall CVD (aHR, 1.02 [95% CI, 1.00-1.05]) or ischemic stroke (aHR, 1.02 [95% CI, 0.98-1.06]). However, when AMD was accompanied by visual disability, there was increased risk of CVD (aHR, 1.17 [95% CI, 1.06-1.29]), myocardial infarction (aHR, 1.18 [95% CI, 1.01-1.37]), and ischemic stroke (aHR, 1.20 [95% CI, 1.06-1.35]). These trends were more evident in women and subjects with cardiometabolic comorbidities. Conclusions AMD with visual disability, but not all AMD, was associated with an increased risk of CVD. Patients with AMD who have visual disability should be targeted for CVD prevention.

Association between glycemic status and age-related macular degeneration: A nationwide population-based cohort study

AIM

The risk of dry and wet age-related macular degeneration (AMD) based on fasting glucose levels and disease duration of type 2 diabetes was investigated.

METHODS

Using a health insurance claims database and the results of health examinations in South Korea, we conducted a retrospective, population-based cohort study of 2,103,604 adults ≥ 45 years of age who were AMD-free based on health checkups in 2009 and observed from January 1, 2011, to December 31, 2018. Glycemic status was classified into five groups: normal, impaired fasting glucose, new-onset diabetes (fasting glucose level ≥ 126 mg/dl but no diabetes diagnosis or diabetes medication), diabetes diagnosis < 5 years, and diabetes ≥ 5 years. According to the presence and absence of choroidal neovascularization, AMD was classified as wet AMD and dry AMD, respectively. Adjusted hazard ratios (HRs) of AMD occurrence were estimated in each category.

RESULTS

For dry AMD (n = 36,271, 1.72%), the HR was 1.192 (1.141-1.245) among subjects with diabetes < 5 years and 1.294 (1.242-1.349) among subjects with diabetes ≥ 5 years compared with subjects with normal glycemic status after adjusting for age, sex, body mass index, lifestyle, and medical history. For wet AMD (n = 12,912, 0.61%), the HR was 1.103 (1.011-1.203) among subjects with new-onset diabetes, 1.252 (1.167-1.344) among subjects with diabetes < 5 years, and 1.506 (1.413-1.605) among subjects with diabetes ≥ 5 years. The HR of AMD was significantly increased among participants ≤ 65 years old and those who did not have hypertension.

CONCLUSIONS

The incidence of dry and wet AMD increased among diabetes patients compared to the normal glycemic status group. These risks increased when the duration of diabetes was 5 years or more. The risk of wet AMD was increased among new-onset diabetes patients. These results suggest that high blood glucose levels without treatment might induce the vision-threatening condition of wet AMD, emphasizing the importance of early blood glucose management.

Prevalence and Associated Risk Factors of Age-Related Macular Degeneration in the Retina Clinic at a Tertiary Center in Makkah Province, Saudi Arabia: A Retrospective Record Review

Background Age-related macular degeneration (AMD) is a progressive disease involving the macular region of the retina and is considered a significant cause of vision loss worldwide. With the increase in life expectancy in various countries, this problem has become more apparent. We retrospectively evaluated the prevalence of AMD among patients visiting the retina clinic at King Abdulaziz University Hospital (Jeddah, Makkah Province, Saudi Arabia) to identify the commonly associated risk factors of AMD. Methods The records of 3,067 individuals from 2017 to 2021 were reviewed. Of these, 1,935 were enrolled in the study. Results The prevalence of AMD among the patients was 4%. Regarding non-modifiable risk factors, age and having a family history of AMD showed a significant association (p = 0.001 and 0.043, respectively). However, sex and nationality were not significantly associated. As for modifiable risk factors, smoking and hypertension demonstrated a significant relationship (p < 0.001 and p = 0.002, respectively). However, the association with diabetes mellitus and dyslipidemia was not significant. Conclusion Our study shows that AMD is widely prevalent in Saudi Arabia and is associated with age, family history, smoking, and hypertension. Therefore, patients at risk of AMD must be screened and managed promptly before disease progression.

Influence of Clinical and Genetic Factors on the Progression of Age-Related Macular Degeneration: A 3-Year Follow-Up

The aim of the present study was to analyze the relationship of age-related macular degeneration (AMD) progression with clinical characteristics, demographic, and environmental risk factors that would affect disease development. In addition, the influence of three genetic AMD polymorphisms (CFH Y402H, ARMS2 A69S, and PRPH2 c.582-67T>A) on AMD progression was investigated. In total, 94 participants with previously diagnosed early or intermediate AMD in at least one eye were recalled for an updated re-evaluation after 3 years. The initial visual outcomes, medical history, retinal imaging data, and choroidal imaging data were collected to characterize the AMD disease status. Among the AMD patients, 48 demonstrated AMD progression, and 46 showed no disease worsening at 3 years. Disease progression was significantly associated with worse initial visual acuity (OR = 6.74, 95% CI = 1.24-36.79, p = 0.03) and the presence of the wet AMD subtype in fellow eyes (OR = 3.79, 95%CI = 0.94-15.2, p = 0.05). In addition, a higher risk of AMD progression appeared in the patients with active thyroxine supplementation (OR = 4.77, CI = 1.25-18.25, p = 0.002). The CC variant of CFH Y402H was associated with AMD advancement compared to the TC+TT phenotype (OR = 2.76, 95% CI: 0.98-7.79, p = 0.05). Identifying risk factors of AMD progression may lead to earlier intervention and better outcomes, preventing the expansion of the late stage of the disease.

Associations of systemic health and medication use with the enlargement rate of geographic atrophy in age-related macular degeneration

BACKGROUND

The associations of geographic atrophy (GA) progression with systemic health status and medication use are unclear.

METHODS

We manually delineated GA in 318 eyes in the Age-Related Eye Disease Study. We calculated GA perimeter-adjusted growth rate as the ratio between GA area growth rate and mean GA perimeter between the first and last visit for each eye (mean follow-up=5.3 years). Patients' history of systemic health and medications was collected through questionnaires administered at study enrolment. We evaluated the associations between GA perimeter-adjusted growth rate and 27 systemic health factors using univariable and multivariable linear mixed-effects regression models.

RESULTS

In the univariable model, GA perimeter-adjusted growth rate was associated with GA in the fellow eye at any visit (p=0.002), hypertension history (p=0.03), cholesterol-lowering medication use (p<0.001), beta-blocker use (p=0.02), diuretic use (p<0.001) and thyroid hormone use (p=0.03). Among the six factors, GA in the fellow eye at any visit (p=0.008), cholesterol-lowering medication use (p=0.002), and diuretic use (p<0.001) were independently associated with higher GA perimeter-adjusted growth rate in the multivariable model. GA perimeter-adjusted growth rate was 51.1% higher in patients with versus without cholesterol-lowering medication use history and was 37.8% higher in patients with versus without diuretic use history.

CONCLUSIONS

GA growth rate may be associated with the fellow eye status, cholesterol-lowering medication use, and diuretic use. These possible associations do not infer causal relationships, and future prospective studies are required to investigate the relationships further.

Increased end-stage renal disease risk in age-related macular degeneration: a nationwide cohort study with 10-year follow-up

Common etiologies between age-related macular degeneration (AMD) and kidney disease advocate a close link between AMD and end-stage renal disease (ESRD). However, the risk of ESRD in people with AMD was not reported. Here, we investigated the association between AMD and the risk of ESRD by using a nationwide, population-based cohort data in Korea. 4,206,862 participants aged 50 years or older were categorized by presence of AMD and visual disability. Risk of ESRD was the primary outcome. Cox regression hazard model was used to examine the hazard ratios (HRs) with adjustment for potential confounders. Stratified analyses by age, sex, baseline kidney function, and cardiometabolic comorbidities were performed. During the mean 9.95 years of follow-up, there were 21,759 incident ESRD events (0.52%). AMD was associated with 33% increased risk of ESRD (adjusted HR [aHR] 1.33, 95% confidence interval [CI] 1.24-1.44), and the risk was even higher when accompanied by visual disability (aHR 2.05, 95% CI 1.68-2.50) than when not (aHR 1.26, 95% CI 1.17-1.37). Age, baseline kidney function, and cardiometabolic comorbidities significantly interact between AMD and the risk of ESRD. Our findings have clinical implications on disease prevention and risk factor management of ESRD in patients with AMD.

Mendelian randomization analyses in ocular disease: a powerful approach to causal inference with human genetic data

Ophthalmic epidemiology is concerned with the prevalence, distribution and other factors relating to human eye disease. While observational studies cannot avoid confounding factors from interventions, human eye composition and structure are unique, thus, eye disease pathogenesis, which greatly impairs quality of life and visual health, remains to be fully explored. Notwithstanding, inheritance has had a vital role in ophthalmic disease. Mendelian randomization (MR) is an emerging method that uses genetic variations as instrumental variables (IVs) to avoid confounders and reverse causality issues; it reveals causal relationships between exposure and a range of eyes disorders. Thus far, many MR studies have identified potentially causal associations between lifestyles or biological exposures and eye diseases, thus providing opportunities for further mechanistic research, and interventional development. However, MR results/data must be interpreted based on comprehensive evidence, whereas MR applications in ophthalmic epidemiology have some limitations worth exploring. Here, we review key principles, assumptions and MR methods, summarise contemporary evidence from MR studies on eye disease and provide new ideas uncovering aetiology in ophthalmology.

Association between Age-Related Macular Degeneration and the Risk of Diabetes Mellitus: A Nationwide Cohort Study

Age-related macular degeneration (AMD) is a degenerative and progressive disease of the macula, the part of the retina that is responsible for central vision. AMD shares some risk factors with diabetes mellitus (DM), but little is known about the risk of DM in individuals with AMD. With the goal of establishing novel perspectives, this study aimed to investigate the association between AMD and the risk of DM using the Korean Nationwide Health Insurance Database. Individuals aged ≥ 50 years who underwent a national health screening program in 2009 were enrolled. Participants were categorized by the presence of AMD and visual disability (VD). The Cox hazard regression model was used to examine hazard ratios (HRs) of DM with adjustment for potential confounders. Stratified analyses by age, sex, and comorbidities (hypertension or dyslipidemia) were also performed. During a mean follow-up of 8.61 years, there were 403,367 (11.76%) DM incidences among the final 3,430,532 participants. The crude HR (95% confidence interval (CI)) was 1.16 (1.13–1.20) for AMD. After adjusting for potential confounders, AMD was associated with a 3% decreased risk of DM (aHR 0.97, 95% CI 0.95–1.00), but no significant association with the risk of DM was found in AMD with VD (aHR 1.03, 95% CI 0.93–1.14). In summary, we did not find an increased risk of DM in individuals with AMD. A 3% decreased risk of DM in patients with AMD is not clinically meaningful. Our study suggests that the association between AMD and the risk of DM is weak, considering the potential confounders. Further studies examining this association are needed to extend our knowledge.

Cardiovascular Disease Risk Factors in US Adults With Vision Impairment

INTRODUCTION

Adults with vision impairment (VI) have a higher prevalence of cardiovascular disease (CVD) compared with those without VI. We estimated the prevalence of CVD and CVD risk factors by VI status in US adults.

METHODS

We used nationally representative data from the 2018 National Health Interview Survey (N = 22,890 adults aged ≥18 years). We estimated the prevalence of self-reported diagnosis of CVD (coronary heart disease [including angina and myocardial infarction], stroke, or other heart disease) by VI status. We used separate logistic regression models to generate adjusted prevalence ratios (aPRs), controlling for sociodemographic covariates, for those with VI (reference group, no VI) for CVD and CVD risk factors: current smoking, physical inactivity, excessive alcohol intake, obesity, hypertension, high cholesterol, and diabetes.

RESULTS

Overall, 12.9% (95% CI, 12.3-13.5) of the sample had VI. The prevalence of CVD was 26.6% (95% CI, 24.7-28.6) in people with VI versus 12.2% (95% CI, 11.7-12.8) in those without VI (aPR = 1.65 [95% CI, 1.51-1.80]). Compared with adults without VI, those with VI had a higher prevalence of all risk factors examined: current smoking (aPR = 1.40 [95% CI, 1.27-1.53]), physical inactivity (aPR = 1.14 [95% CI, 1.06-1.22]), excessive alcohol intake (aPR = 1.29 [95% CI, 1.08-1.53]), obesity (aPR = 1.28 [95% CI, 1.21-1.36]), hypertension (aPR = 1.29 [95% CI, 1.22-1.36]), high cholesterol (aPR = 1.21 [95% CI, 1.14-1.29]), and diabetes (aPR = 1.54 [95% CI, 1.38-1.72]).

CONCLUSION

Adults with VI had a higher prevalence of CVD and CVD risk factors compared with those without VI. Effective clinical and lifestyle interventions, adapted to accommodate VI-related challenges, may help reduce CVD risk in adults with VI.

Bioengineering approaches for modelling retinal pathologies of the outer blood-retinal barrier

Alterations of the junctional complex of the outer blood-retinal barrier (oBRB), which is integrated by the close interaction of the retinal pigment epithelium, the Bruch's membrane, and the choriocapillaris, contribute to the loss of neuronal signalling and subsequent vision impairment in several retinal inflammatory disorders such as age-related macular degeneration and diabetic retinopathy. Reductionist approaches into the mechanisms that underlie such diseases have been hindered by the absence of adequate in vitro models using human cells to provide the 3D dynamic architecture that enables expression of the in vivo phenotype of the oBRB. Conventional in vitro cell models are based on 2D monolayer cellular cultures, unable to properly recapitulate the complexity of living systems. The main drawbacks of conventional oBRB models also emerge from the cell sourcing, the lack of an appropriate Bruch's membrane analogue, and the lack of choroidal microvasculature with flow. In the last years, the advent of organ-on-a-chip, bioengineering, and stem cell technologies is providing more advanced 3D models with flow, multicellularity, and external control over microenvironmental properties. By incorporating additional biological complexity, organ-on-a-chip devices can mirror physiologically relevant properties of the native tissue while offering additional set ups to model and study disease. In this review we first examine the current understanding of oBRB biology as a functional unit, highlighting the coordinated contribution of the different components to barrier function in health and disease. Then we describe recent advances in the use of pluripotent stem cells-derived retinal cells, Bruch's membrane analogues, and co-culture techniques to recapitulate the oBRB. We finally discuss current advances and challenges of oBRB-on-a-chip technologies for disease modelling.

Correlation between genetic and environmental risk factors for age-related macular degeneration in Brazilian patients

PURPOSE

To analyze the correlations between age-related macular degeneration (AMD) and genetic and environmental risk factors for in a Brazilian population.

DESIGN

Cross-sectional study with a control group.

METHODS

We collected data on 236 participants 50 years of age or older (141 with AMD and 95 controls without the disease). Data was obtained using a questionnaire and included information on demographics, ocular and medical history, family history of AMD, lifestyle, and smoking and drinking habits. Genetic evaluations included direct sequencing for the LOC387715 (rs10490924) variant, as well as PCR and enzymatic digestion for the CFH Y402H (rs1061170) and HTRA1 (rs11200638) variants. We performed a risk assessment of environmental risk factors and genetic variants associated with AMD and determined correlations between AMD and the data collected using multiple linear regression analysis.

RESULTS

Of the 141 AMD cases, 99 (70%) had advanced AMD in at least one eye (57% neovascular AMD and 13% geographic atrophy), and 42 (30%) had not-advanced AMD. Family history of AMD (OR: 6.58; 95% CI: 1.94-22.31), presence of cardiovascular disease (CVD) (OR: 2.39; 95% CI: 1.08-5.28), low physical activity level (OR: 1.39; 95% CI: 0.82-2.37), and high serum cholesterol (OR: 1.49; 95% CI: 0.84-2.65) were associated with an increased risk for AMD. There was a significant association between CVD and incidence of advanced AMD (OR: 2.29; 95% CI 0.81-6.44). The OR for the risk allele of the LOC387715 gene, the CFH gene and the HTRA1 gene were 2.21 (95% CI: 1.47-3.35), 2.27 (95% CI: 1.52-3.37), and 2.76 (95% CI: 1.89-4.03), respectively. In the stepwise multiple linear regression analyses, the HTRA1 and CFH risk alleles, family history of AMD, the LOC387715 risk allele, and CVD were associated with an increased risk of AMD for a total of 25.6% contribution to the AMD phenotype.

CONCLUSIONS

The analysis correlating environmental and genetic risk factors such as family history of AMD, and CVD and the variants of HTRA1, CFH, and LOC387715 genes showed an expressive contribution for the development of AMD among this admixed population.

Association between Cataract Surgery and Age-Related Macular Degeneration: A Systematic Review and Meta-Analysis

Purpose

We performed a systematic review and meta-analysis to evaluate the association between cataract surgery and the development and progression of AMD.

Methods

This meta-analysis was registered at PROSPERO (CRD42017077962). We conducted a systematic literature search in August 2020 in Embase and PubMed and included cohort studies, case-control studies, or randomized controlled trials (RCTs) if they examined the association between cataract surgery and AMD. Odds ratio (OR) was used as a measure of the association with a random effect model. The analysis was further stratified by factors that could affect the outcomes.

Results

15 studies were included in this study. In the overall analysis, cataract surgery was significantly associated with the incidence of late AMD (OR, 1.80; 95% CI, 1.26–2.56; P = 0.001), particularly geographic atrophy (OR, 3.20; 95% CI, 1.90–5.39; P ≤ 0.001). No significant associations were observed between cataract surgery and the incidence of early AMD. Subgroup analysis showed that the OR for incidence of early and late AMD was significantly higher for cataract surgery performed more than 5 years compared with less than 5 years. We also found an increased risk of progression of AMD after cataract surgery performed more than 5 years (OR, 1.97; 95% CI, 1.29–3.01; P = 0.002).

Conclusions

Our results suggest that cataract surgery may be associated with an increased risk of late AMD development and AMD progression. In addition, increasing the follow-up time since cataract surgery may further increase the risk for the development and progression of AMD. In the future, prospective multicenter studies with well-designed RCTs are required to confirm our findings.

Unilateral Cilioretinal Artery and Advanced Age-Related Macular Degeneration: A Retrospective Cross-Sectional Study

PURPOSE

To investigate the association between the presence of a cilioretinal artery (CRA) and advanced age-related macular degeneration (AMD), including the prevalence of choroidal neovascularization (CNV) and geographic atrophy (GA).

DESIGN

Retrospective cross-sectional study.

METHODS

This was a single-center study. A total of 738 patients with AMD who underwent optical coherence tomography angiography (OCTA) were included in the study. Fundus photographs were reviewed to determine the presence of the CRA. In patients with a unilateral CRA, paired tests were performed between eyes with and without the CRA to compare AMD severity and prevalence of CNV and GA. The main outcomes of interest were AMD stage and prevalence of CNV and GA. Macular vasculature, including vessel density, perfusion density, and foveal avascular zone, were examined using OCTA.

RESULTS

A total of 174 eyes from 87 patients with a unilateral CRA were examined. A total of 27.8% and 8.1% of patients had a CRA in 1 eye and both eyes, respectively. Eyes with a CRA showed lower AMD stage (4-step AREDS category; P = .037) and a lower prevalence of CNV (23.0% vs 41.4%; P = .024) than those without a CRA. The prevalence of GA and macular vessel density, perfusion density, and foveal avascular zone measured by OCTA were similar in both groups.

CONCLUSIONS

In the eyes with a CRA, AMD stage and prevalence of CNV were lower than those in the eyes without a CRA. However, the effect of the CRA on the macular vascular system remains unclear.

Association of neovascular age-related macular degeneration with migraine

Patients with early onset vascular pathology have been reported to manifest neovascular age-related macular degeneration (AMD). While the blood vessels involved in pathogenesis of migraine remains controversial, it is generally accepted that a major contributor is blood vessel pathology. This study aimed to examine the association between migraine and AMD using a nationwide population-based dataset. Retrospective claims data were collected from the Taiwan National Health Insurance Research Database. We identified 20,333 patients diagnosed with neovascular AMD (cases), and we selected 81,332 propensity score-matched controls from the remaining beneficiaries in Taiwan's National Health Insurance system. We used Chi-square tests to explore differences in the prevalence of migraine prior to the index date between cases and controls. We performed multiple logistic regressions to estimate the odds of prior migraine among neovascular AMD patients vs. controls after adjusting for age, sex, monthly income, geographic location, residential urbanization level, hyperlipidemia, diabetes, coronary heart disease, hypertension, and previous cataract surgery. A total of 5184 of sample patients (5.1%) had a migraine claim before the index date; 1215 (6.1%) among cases and 3969 (4.9%) among controls (p < 0.001), with an unadjusted OR of 1.239 (95% CI 1.160~1.324, p < 0.001) for prior migraine among cases relative to controls. Furthermore, the adjusted OR was 1.201 (95% CI 1.123~1.284; p < 0.001) for AMD cases relative to controls. The study offers population-based evidence that persons with migraine have 20% higher risk of subsequently being diagnosed with neovascular AMD.

Associations between systemic medications and development of wet age-related macular degeneration

PURPOSE

To examine whether systemic medications are associated with the subsequent development of wet age-related macular degeneration (AMD).

METHODS

A retrospective study of 259 562 individuals based on registry data, from January 1, 2001, to December 31, 2017. End-point event was the International Classification of Diseases (ICD)-10 diagnosis for wet AMD. Association between use of systemic medication covering 85 generic drugs categorized according to Anatomical Therapeutic Chemical (ATC) codes and the incidence of wet AMD was evaluated using multivariate Poisson regression model (adjusted for age, sex, diabetes, cancer and socioeconomic group) and nested case-control design.

RESULTS

The mean length of follow-up was 9.84 years. The number of cases with wet AMD was 2947 and incidence rate was 1.15 per 1000 person-years. After adjustment, we observed an increased risk for the development of wet AMD for patients exposed to amlodipine (IRR 1.33, 95% CI 1.16-1.53), or felodipine (1.24, 95% CI 1.02-1.50). Similarly, an increased risk of wet AMD was associated with the use of bicalutamide (2.14, 95% CI 1.14-4.02), estradiol (1.20, 95% CI 1.03-1.40) and atorvastatin (1.22, 95% CI 1.05-1.43). Of note, digoxin (0.72, 95% CI 0.57-0.91), and ramipril (0.80, 95% CI 0.65-0.99) users had a lower incidence of wet AMD.

CONCLUSIONS

Our findings suggest that the use of second-generation calcium channel blockers could be associated with an increased risk for wet AMD development. Of note, the incidence of wet AMD seemed to be lower in patients using ramipril and digoxin. More studies are needed to elucidate the associations further.

Intravitreal anti-VEGF therapy is not associated with a higher risk of all-cause mortality in patients with macular oedema caused by posterior segment vascular diseases

PURPOSE

To examine whether real-world clinical patients with macular oedema (MO) receiving intravitreal antivascular endothelial growth factor (VEGF) therapy have a higher mortality compared with a matched reference population.

METHODS

A population-based, retrospective cohort study of 26 386 patients from Finland, from January 1, 2001, to December 31, 2017. Index patients were identified through the Caring Epidemiology Project database, receiving at least one intravitreal anti-VEGF injection for wet age-related macular degeneration (AMD, n = 2243, 48.61%), diabetic MO (n = 744, 16.12%), MO due to retinal vascular occlusion (n = 589, 12.77%), or other MO (n = 1038, 22.5%). For each individual treated with intravitreal injection (n = 4614), five age- , sex- , calendar year- and hospital district- matched control individuals (n = 21 772) were chosen. Baseline data of chronic conditions were available. All-cause and cause-specific mortality was analysed using Cox´s proportional hazards model.

RESULTS

In general, the anti-VEGF treated patients had a higher prevalence of systemic conditions, including diabetes (60.1% vs. 46.8%, p < 0.001), chronic hypertension (38.4% vs. 34.6%, p < 0.001), in hospital-treated ischaemic heart disease (23.1% vs. 21.5%, p = 0.014), and glaucoma (11.1% vs. 6.3%, p < 0.001) than controls. There was no difference in all-cause mortality between the anti-VEGF treated patients and matched controls (p = 0.62). In unadjusted Kaplan-Meier analysis of wet AMD subgroup, all-cause mortality was lower in anti-VEGF treated patients than matched controls (p = 0.015), but adjusted Cox´s proportional hazards model showed no difference in the risk of all-cause mortality (HR 0.85, 95% CI 0.66-1.09).

CONCLUSIONS

Intravitreal anti-VEGF therapy was not associated with an increase in the risk of mortality in patients with MO compared with age- and sex-matched controls.

Obesity and risk of age-related eye diseases: a systematic review of prospective population-based studies

BACKGROUND

Obesity is a public health challenge worldwide. The relationship between obesity and age-related eye diseases including cataract, glaucoma, age-related macular degeneration (AMD) and diabetic retinopathy (DR) have remained elusive.

DESIGN AND METHODS

We conducted a systematic review of three electronic databases for longitudinal population-based studies that described associations between measures of obesity including body mass index (BMI), waist-circumference (WC), and waist-to-hip ratio (WHR), and age-related eye diseases.

RESULTS

Our search yielded 1731 articles, of which 14, 10, 16 and 8 articles met our eligibility criteria for cataract, glaucoma, AMD and DR, respectively. BMI-defined obesity was positively associated with incident cataract, incident AMD and incident DR in Western populations, but in Asian populations associations for incident AMD were not significant and associations for incident DR were inverse. WC-defined obesity was associated with incident glaucoma in non-Western populations. WHR-defined obesity but not BMI-defined obesity was associated with the incidence or progression of AMD in two Western studies.

CONCLUSIONS

Overall, we found strong evidence supporting associations between obesity and age-related eye diseases. Further research on the association of abdominal obesity and effect of weight loss and physical activity on age-related eye diseases is warranted to support clinical and public health recommendations.

The impact of vascular risk factors on the thickness and volume of the choroid in AMD patients

Disturbances in choroidal microcirculation may lead to the onset and progression of age-related macular degeneration (AMD). We aimed to assess changes in the choroidal volume and thickness in the macular region in AMD eyes and to investigate whether coexisting vascular risk factors alter choroidal status. We enrolled 354 AMD patients (175 dry, 179 wet AMD) and 121 healthy controls. All participants underwent a complete ophthalmologic examination and assessment of choroidal thickness and volume. A multivariate analysis adjusted for age, sex, and smoking status revealed that wet AMD was an independent factor associated with higher average thickness of the central ring area (ATC) and average volume of the central ring area (AVC) and lower choroidal vascularity index (CVI) compared to controls (β =  + 0.18, p = 0.0007, β =  + 0.18, p = 0.0008, respectively) and to dry AMD (β =  + 0.17, p = 0.00003 for both ATC and AVC and β =  - 0.30 p < 0.0001 for CVI). ATC, AVC and average volume (AV) were lower in AMD patients with hypertension and ischaemic heart disease (IHD). The duration of hypertension was inversely correlated with ATC, AVC and AV (Rs =  - 0.13, p < 0.05; Rs =  - 0.12; p < 0.05, Rs =  - 0.12; p < 0.05, respectively) while IHD duration negatively correlated with AV (Rs =  - 0.15, p < 0.05). No such associations were observed in the control group. Our findings show that the choroidal vascular system in eyes with AMD is much more susceptible to damage in the presence than in the absence of systemic vascular disease.

Interlink between Inflammation and Oxidative Stress in Age-Related Macular Degeneration: Role of Complement Factor H

Age-related macular degeneration (AMD) heads the list of legal blindness among the elderly population in developed countries. Due to the complex nature of the retina and the variety of risk factors and mechanisms involved, the molecular pathways underlying AMD are not yet fully defined. Persistent low-grade inflammation and oxidative stress eventually lead to retinal pigment epithelium dysfunction and outer blood-retinal barrier (oBRB) breakdown. The identification of AMD susceptibility genes encoding complement factors, and the presence of inflammatory mediators in drusen, the hallmark deposits of AMD, supports the notion that immune-mediated processes are major drivers of AMD pathobiology. Complement factor H (FH), the main regulator of the alternative pathway of the complement system, may have a key contribution in the pathogenesis of AMD as it is able to regulate both inflammatory and oxidative stress responses in the oBRB. Indeed, genetic variants in the CFH gene account for the strongest genetic risk factors for AMD. In this review, we focus on the roles of inflammation and oxidative stress and their connection with FH and related proteins as regulators of both phenomena in the context of AMD.

Physics-based modeling of Age-related Macular Degeneration-A theoretical approach to quantify retinal and choroidal contributions to macular oxygenation

We developed a mathematical model to characterize how macular oxygenation may be affected by abnormalities in the retinal and choroidal oxygen supplies. The macular region is modeled as a layered structure including: ganglion cell and nerve fiber layers, inner plexiform layer, inner nuclear layer, outer plexiform layer, outer nuclear layer, inner segment of photoreceptors layer and retinal pigmented epithelium. Each layer is characterized by specific levels of oxygen consumption. The vitreous and the choroid are located at the macula boundary and provide oxygen via boundary conditions of Dirichlet type. The three capillary plexi (superficial, intermediate, and deep) of the retinal circulation pierce the macular layers and provide oxygen via a volumetric source that depends on the retinal blood flow. Oxygen profiles through the macular tissue are calculated by simulating the balance among oxygen supply, consumption and diffusion in: (a) physiological baseline conditions; (b) retinal blood flow reduced by 10%, 30% and 50% with respect to baseline; (c) choroidal oxygen level diminished by 10%, 30% and 50% with respect to baseline. Model simulations predict that: (1) the oxygenation of the foveal avascular zone is not affected by reduction in retinal blood flow; (2) a reduction in choroidal oxygen supply significantly affects the outer layers, especially the photoreceptors and outer nuclear layers; (3) the impact of reduction in choroidal oxygen supply is larger in the region more proximal to the macular center; (4) the impact of reduction in retinal blood flow is larger in the region more proximal to the macular periphery. The proposed mathematical model suggests that changes in retinal and choroidal oxygen supplies impact the oxygenation of the macular tissue differentially. These results may help better understand the pathogenesis of macular degeneration.

The Relationship between Age-Related Macular Degeneration and Cardiovascular Disease: A Meta-Analysis

Background:

Age-related macular degeneration (AMD) and cardiovascular disease (CVD) share pathogenic mechanisms, and their lead-lag relationship remains unclear. We performed a meta-analysis of data from longitudinal studies to evaluate the interactive association between age-related macular degeneration (AMD) and cardiovascular disease (CVD).

Methods:

A literature search was performed in PubMed, Embase, and Cochrane Library up to Feb 2019. Estimates were pooled by study quality and type of AMD and CVD. Publication bias was assessed by Begg’s test.

Results:

We identified nine studies for the risk of AMD in CVD and ten studies for the risk of CVD in AMD. Overall, evidence for the risk of CVD in AMD patients was most robust. Both early and late AMD preceded CVD, but more solid significance existed in late AMD. Among the types of CVD, stroke was more tightly associated with AMD than coronary heart disease. Publication bias was not significant in either direction.

Conclusion:

AMD is a risk factor for CVD, which is primarily driven by the increased risk of stroke in patients with late AMD. Moreover, these results suggested that AMD treatment and screening for CVD in AMD patients may have unexplored clinical benefits.

RETINAL ARTERIAL DILATION IS IMPAIRED IN EYES WITH DRUSEN AND RETICULAR PSEUDODRUSEN

PURPOSE

To analyze static characteristics and dynamic functionality of retinal vessels in eyes with drusen and reticular pseudodrusen (RPD) using dynamic vessel analyzer.

METHODS

Patients with clinical diagnosis of isolated RPD or medium-large drusen and healthy controls were enrolled in the study between July 2016 and May 2018. Participants underwent complete ophthalmologic examination, including enhanced depth imaging structural optical coherence tomography, dynamic retinal vessel analysis, and static retinal vessel analysis.

RESULTS

Twenty-eight eyes of 23 patients with drusen (9 men, mean age 77 ± 6 years), 22 eyes of 16 patients with RPD (7 men, mean age: 76 ± 6 years), and 22 eyes of 22 control subjects (11 men, mean age of 75 ± 6 years) were enrolled. Static retinal vessel analysis did not show any significant difference between the three groups for the central retinal artery equivalent (P = 0.11), the central retinal vein equivalent (P = 0.27), and the arteriovenous ratio (P = 0.30). Dynamic vessel analysis showed significantly reduced arterial dilation in eyes with drusen (P = 0.0001) and RPD (P = 0.015) compared with control subjects. No significant difference was seen between drusen and RPD groups (P = 0.32). Dynamic vessel analysis of retinal veins showed no differences between the three groups (P = 0.10).

CONCLUSION

Dynamic vessel analysis in eyes with drusen and RPD revealed an impaired retinal arterial dilation in response to flicker light stimulation, which further supports the relationship between cardiovascular risk and age-related macular degeneration.

Macular Function in Early and Intermediate Age-related Macular Degeneration: Correlation with the Simplified Thea Risk Assessment Scale (STARS)

Purpose

Early detection of retinal dysfunction in age-related macular degeneration (AMD) may be important for both prevention and treatment. The aim of this study was to evaluate in early and intermediate AMD the correlation of macular function, assessed by the focal electroretinogram (fERG), with the Simplified Thea Risk Assessment Scale (STARS), a simple 13-item self-administered questionnaire.

Methods

We recorded a fERG (18°, 41 Hz) in 84 patients with AMD (40 male and 44 female, age 55–87 years, visual acuity 20/40–20/20), who had undergone a 5-year clinical ophthalmic and general follow-up. Sixty-six patients had early and 17 patients intermediate AMD. Fifty healthy subjects, in a comparable age range, served as controls. The fERG amplitude (in microVolts) was the main outcome variable. STARS was calculated for each patient.

Results

Compared with controls, fERG amplitudes were significantly reduced, on average, in both early and intermediate patients with AMD (P < 0.01). In both groups, fERG amplitudes tended to decrease with age and to increase with visual acuity and were negatively correlated with STARS (early r = –0.6, P < 0.01; intermediate, r = –0.50, P < 0.05). fERG losses were greatest in patients with a STARS score of greater than 20.

Conclusions

In early and intermediate AMD, STARS robustly predicted central retinal function, as assessed by fERG, supporting the combined use of both parameters to estimate the clinical risk of visual function loss.

Translational Relevance

The STARS may predict macular function in AMD and could be used in the daily clinical practice to estimate the risk of visual function loss in early disease stages.

High-Density Lipoprotein Cholesterol in Age-Related Ocular Diseases

There is limited understanding of the specific role of high-density lipoprotein cholesterol (HDL-C) in the development of various age-related ocular diseases, despite it being a common measurable biomarker in lipid profiles. This literature review summarizes current knowledge of the role of HDL-C, if any, in pathogenesis and progression of four age-related ocular diseases, namely age-related macular degeneration (AMD), age-related cataract, glaucoma, and diabetic retinopathy (DR), and will primarily discuss epidemiological and genetic evidence.

Risk factors for progression of age-related macular degeneration

Purpose

Age‐related macular degeneration (AMD) is a degenerative disease of the macula, often leading to progressive vision loss. The rate of disease progression can vary among individuals and has been associated with multiple risk factors. In this review, we provide an overview of the current literature investigating phenotypic, demographic, environmental, genetic, and molecular risk factors, and propose the most consistently identified risk factors for disease progression in AMD based on these studies. Finally, we describe the potential use of these risk factors for personalised healthcare.

Recent findings

While phenotypic risk factors such as drusen and pigment abnormalities become more important to predict disease progression during the course of the disease, demographic, environmental, genetic and molecular risk factors are more valuable at earlier disease stages. Demographic and environmental risk factors such as age and smoking are consistently reported to be related to disease progression, while other factors such as sex, body mass index (BMI) and education are less often associated. Of all known AMD variants, variants that are most consistently reported with disease progression are rs10922109 and rs570618 in CFH, rs116503776 in C2/CFB/SKIV2L, rs3750846 in ARMS2/HTRA1 and rs2230199 in C3. However, it seems likely that other AMD variants also contribute to disease progression but to a lesser extent. Rare variants have probably a large effect on disease progression in highly affected families. Furthermore, current prediction models do not include molecular risk factors, while these factors can be measured accurately in the blood. Possible promising molecular risk factors are High‐Density Lipoprotein Cholesterol (HDL‐C), Docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), zeaxanthin and lutein.

Summary

Phenotypic, demographic, environmental, genetic and molecular risk factors can be combined in prediction models to predict disease progression, but the selection of the proper risk factors for personalised risk prediction will differ among individuals and is dependent on their current disease stage. Future prediction models should include a wider set of genetic variants to determine the genetic risk more accurately, and rare variants should be taken into account in highly affected families. In addition, adding molecular factors in prediction models may lead to preventive strategies and personalised advice.

Central Role of Oxidative Stress in Age-Related Macular Degeneration: Evidence from a Review of the Molecular Mechanisms and Animal Models

Age-related macular degeneration (AMD) is a common cause of visual impairment in the elderly. There are very limited therapeutic options for AMD with the predominant therapies targeting vascular endothelial growth factor (VEGF) in the retina of patients afflicted with wet AMD. Hence, it is important to remind readers, especially those interested in AMD, about current studies that may help to develop novel therapies for other stages of AMD. This study, therefore, provides a comprehensive review of studies on human specimens as well as rodent models of the disease, to identify and analyze the molecular mechanisms behind AMD development and progression. The evaluation of this information highlights the central role that oxidative damage in the retina plays in contributing to major pathways, including inflammation and angiogenesis, found in the AMD phenotype. Following on the debate of oxidative stress as the earliest injury in the AMD pathogenesis, we demonstrated how the targeting of oxidative stress-associated pathways, such as autophagy and nuclear factor erythroid 2-related factor 2 (Nrf2) signaling, might be the futuristic direction to explore in the search of an effective treatment for AMD, as the dysregulation of these mechanisms is crucial to oxidative injury in the retina. In addition, animal models of AMD have been discussed in great detail, with their strengths and pitfalls included, to assist inform in the selection of suitable models for investigating any of the molecular mechanisms.

Choroidal Neovascularization: Mechanisms of Endothelial Dysfunction

Many conditions affecting the heart, brain, and even the eyes have their origins in blood vessel pathology, underscoring the role of vascular regulation. In age-related macular degeneration (AMD), there is excessive growth of abnormal blood vessels in the eye (choroidal neovascularization), eventually leading to vision loss due to detachment of retinal pigmented epithelium. As the advanced stage of this disease involves loss of retinal pigmented epithelium, much less attention has been given to early vascular events such as endothelial dysfunction. Although current gold standard therapy using inhibitors of vascular endothelial growth factor (VEGF) have achieved initial successes, some drawbacks include the lack of long-term restoration of visual acuity, as well as a subset of the patients being refractory to existing treatment, alluding us and others to hypothesize upon VEGF-independent mechanisms. Against this backdrop, we present here a nonexhaustive review on the vascular underpinnings of AMD, implications with genetic and systemic factors, experimental models for studying choroidal neovascularization, and interestingly, on both endothelial-centric pathways and noncell autonomous mechanisms. We hope to shed light on future research directions in improving vascular function in ocular disorders.

Hypertension, antihypertensive medications use and risk of age-related macular degeneration in California Teachers Cohort

Sustained and inadequately controlled hypertension can promote the development of age-related macular degeneration (AMD) through multiple biologic pathways. Epidemiologic studies of high blood pressure, antihypertensive therapies, and the risk of AMD thus far have been inconclusive. However, few studies evaluated risks according to the use of different classes of antihypertensive drugs or took combinations of use into account. We performed a prospective cohort study by linking the California Teachers Study (CTS) cohort (N = 88 481) to statewide hospital discharge records up to December 31, 2012. History of high blood pressure, regular use of antihypertensive medications, and comprehensive risk factor information was collected via self-administered questionnaires at baseline in 1995-1996, and information on specific classes of antihypertensive drugs was provided by a subsample of CTS participants who completed a follow-up questionnaire in 2000. We identified 1762 female teachers with AMD during 14.8 years of follow-up on average. Applying Cox proportional hazard regression, we estimated increased risks of AMD among women treated for hypertension at baseline (HR = 1.15, 95% CI: 1.03, 1.30); the magnitude of the association increased with longer duration of antihypertensive treatment. In the subsample with more specific information on type of medication use, we estimated a 45% increased risk of AMD among women receiving diuretics as monotherapy compared to women with medications more potent than diuretics (HR = 1.45, 95% CI 1.10, 1.90). In women treated with a combination of antihypertensive drugs, we observed no increased risk of AMD for any individual class of drugs.

Associations between CYP2J2 (-76G>T) rs890293 polymorphism and age-related macular degeneration

Backgroung. Age-related macular degeneration (AMD) is a disease of the macula, which significantly affects the eyesight and leads to irreversible central vision loss. The etiopathogenesis of AMD is still not absolutely clear. It is thought that age-related macular degeneration has a multifactorial etiology, the development of which may be caused by interrelation of environmental with innate factors, while genetic factors also have an impact. Macular degenerative changes occur due to the formation of drusen, about 40% of which is lipids. As the CYP2J2 gene is involved in the metabolism of lipids, it was selected for investigation in this study.

PURPOSE

To determine the relation between early stage and exudative AMD and CYP2J2 (-76G>T) gene rs890293 polymorphism in a Lithuanian population.

METHODS

The study enrolled 204 patients with early AMD, 197 patients with exudative AMD and 198 healthy controls. Samples of DNA from peripheral white blood cells were purified using commercial kits. The genotyping was carried out using a real-time PCR method.

RESULTS

The CYP2J2 (-76G>T) rs890293 TT genotype in patients with early AMD was statistically significantly less frequent than in the control group: 0% vs. 2.5% (P=0.028). There were no significant differences in rs890293 gene polymorphisms between the exudative AMD and control groups. Also, the CYP2J2 (-76G>T) rs890293 TT genotype was statistically significantly less frequent in older early AMD patients (≥65 years) compared to control group persons (≥65 years): 0% vs. 5.4% (P=0.03).

CONCLUSION

The CYP2J2 (-76G>T) TT genotype may be associated with reduced manifestation of early stage AMD; therefore, a larger sample size is required for further analysis.

INCREASED INCIDENCE OF CUTANEOUS KERATINOCYTIC AND MELANOCYTIC MALIGNANCIES IN PATIENTS WITH AGE-RELATED MACULAR DEGENERATION

PURPOSE

The relationship between age-related macular degeneration (AMD) and malignancy, especially cutaneous malignancies, is not well studied. We investigated a possible association between AMD and cutaneous malignancies.

METHODS

A retrospective, consecutive review of all patients who had received at least 1 intravitreal injection for wet AMD between January 1, 2004, and December 31, 2013, was conducted using the Rochester Epidemiology Project in Olmsted County, Minnesota. Age- and sex-matched control groups included 473 pre-anti-vascular endothelial growth factor era wet AMD patients, 504 concurrent time dry AMD patients, and 504 patients with no AMD. The rates of AMD and overall malignancy, cutaneous malignancies, and specific types of cutaneous malignancies were compared between groups of patients.

RESULTS

Patients with wet AMD incurred an increased rate of overall malignancies compared to patients with dry AMD {52.8% wet AMD (confidence interval [CI]: 48.3-57.2) vs. 43.7% dry AMD (CI: 39.3-48.1); P= 0.003} or those without AMD (52.8% wet AMD [CI: 48.3-57.2] vs. 35.3% no AMD [CI: 31.1-39.7]; P = <0.001). Patients with dry AMD also had higher rates of malignancy than those without AMD (43.7% dry AMD [CI: 39.3-48.1] vs. 35.3% no AMD [CI: 31.1-39.7]; P = 0.007). Rate of cutaneous malignancies was increased in patients with wet AMD compared to patients with dry AMD (24.4% wet AMD [CI: 20.7-28.4] vs. 14.6% dry AMD [CI: 11.5-17.9]; P = <0.001) and those with no AMD (24.4% wet AMD [CI: 20.7-28.4] vs. 9.7% no AMD [CI: 7.3-12.7]; P = <0.001).

CONCLUSION AND RELEVANCE

To the best of our knowledge, this is the first report to establish an association between AMD and cutaneous malignancies, supporting a possible discussion of the association when a patient presents with one of the two conditions.

The Contribution of Fluoride to the Pathogenesis of Eye Diseases: Molecular Mechanisms and Implications for Public Health

This study provides diverse lines of evidence demonstrating that fluoride (F) exposure contributes to degenerative eye diseases by stimulating or inhibiting biological pathways associated with the pathogenesis of cataract, age-related macular degeneration and glaucoma. As elucidated in this study, F exerts this effect by inhibiting enolase, τ-crystallin, Hsp40, Na⁺, K⁺-ATPase, Nrf2, γ -GCS, HO-1 Bcl-2, FoxO1, SOD, PON-1 and glutathione activity, and upregulating NF-κB, IL-6, AGEs, HsP27 and Hsp70 expression. Moreover, F exposure leads to enhanced oxidative stress and impaired antioxidant activity. Based on the evidence presented in this study, it can be concluded that F exposure may be added to the list of identifiable risk factors associated with pathogenesis of degenerative eye diseases. The broader impact of these findings suggests that reducing F intake may lead to an overall reduction in the modifiable risk factors associated with degenerative eye diseases. Further studies are required to examine this association and determine differences in prevalence rates amongst fluoridated and non-fluoridated communities, taking into consideration other dietary sources of F such as tea. Finally, the findings of this study elucidate molecular pathways associated with F exposure that may suggest a possible association between F exposure and other inflammatory diseases. Further studies are also warranted to examine these associations.

Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency and Late-stage Age-Related Macular Degeneration

Purpose: Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly in Western Countries. Evidence indicates that Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency, a common genetic abnormality, may protect against ischemic heart and cerebrovascular disease, ocular vascular disorders, and colorectal cancer. This study was undertaken to ascertain whether G6PD deficiency may protect against AMD. Materials and Methods: 79 men with late-stage AMD and 79 male, age-matched cataract controls without AMD were recruited in March-December 2016. Smoking status, clinical history, and drug use were recorded. A blood sample was taken from each participant. Complete blood count, hemoglobin, glucose, creatinine, cholesterol, triglycerides, transaminases, bilirubin, and erythrocyte G6PD activity were measured. Stepwise logistic regression was used to investigate the association between G6PD deficiency and AMD. Results: G6PD deficiency was found in 7 (8.9%) AMD patients and 8 (10.1%) controls, a not statistically significant difference. Stepwise logistic regression disclosed that AMD was significantly associated with increased diastolic blood pressure (OR=1.09, 95% CI=1.03-1.15, P=0.02) and LDL-cholesterol (OR=1.02, 95% CI=1.0001-1.03, P=0.049) and lower values of white blood cell (WBC) count (OR=0.71, 95% CI=0.56-0.88, P=0.02) and aspartate aminotransferase (AST) (OR=0.92, 95% CI=0.85-0.99, P=0.044). Conclusion: Results suggest that G6PD deficiency has no protective effect on nor is a risk factor for AMD. Larger studies are necessary to confirm whether increased diastolic blood pressure and LDL-cholesterol and lower values of WBC count and AST are risk factors for AMD.

HDL-cholesterol levels and risk of age-related macular degeneration: a multiethnic genetic study using Mendelian randomization

Background

Dyslipidemia, particularly high-density lipoprotein cholesterol (HDL-C), has recently been implicated in the pathogenesis of age-related macular degeneration (AMD), the leading cause of vision loss. However, epidemiological studies have yielded conflicting results.

Methods

We investigated the causal role of plasma lipid levels in AMD in multiethnic populations comprising 16 144 advanced AMD cases and 17 832 controls of European descent, together with 2219 cases and 5275 controls of Asian descent, using Mendelian randomization in three models. Model 1 is a conventional meta-analysis which does not account for pleiotropy of instrumental variable (IV) effects. Model 2 is a univariate, inverse variance weighted regression analysis that accounts for potential unbalanced pleiotropy using MR-Egger method. Finally, Model 3 is a multivariate regression analysis that addresses pleiotropy by MR-Egger method and by adjusting for effects on other lipid traits.

Results

A 1 standard deviation (SD) higher HDL-cholesterol level was associated with an odds ratio (OR) for AMD of 1.17 (95% confidence interval: 1.07–1.29) in Europeans (P = 6.88 × 10^–4) and of 1.58 (1.24–2.00) in Asians (P = 2.92 × 10^–4) in Model 3. The corresponding OR estimates were 1.30 (1.09–1.55) in Europeans (P = 3.18 × 10^–3) and 1.42 (1.11—1.80) in Asians (P = 4.42 × 10^–3) in Model 1, and 1.21 (1.11–1.31) in Europeans (P = 3.12 × 10^–5) and 1.51 (1.20–1.91) in Asians (P = 7.61 × 10^–4) in Model 2. Conversely, neither LDL-C (Europeans: OR = 0.96, P = 0.272; Asians: OR = 1.02, P = 0.874; Model 3) nor triglyceride levels (Europeans: OR = 0.91, P = 0.102; Asians: OR = 1.06, P = 0.613) were associated with AMD. We also assessed the association between lipid levels and polypoidal choroidal vasculopathy (PCV) in Asians, a subtype of AMD, and found a similar trend for association of PCV with HDL-C levels.

Conclusions

Our study shows that high levels of plasma HDL-C are causally associated with an increased risk for advanced AMD in European and Asian populations, implying that strategies reducing HDL-C levels may be useful to prevent and treat AMD.

Evaluation of serum sphingolipids and the influence of genetic risk factors in age-related macular degeneration

Sphingolipids are bioactive molecules associated with oxidative stress, inflammation, and neurodegenerative diseases, but poorly studied in the context of age-related macular degeneration (AMD), a prevalent sight-threatening disease of the ageing retina. Here, we found higher serum levels of hexosylceramide (HexCer) d18:1/16:0 in patients with choroidal neovascularization (CNV) and geographic atrophy (GA), two manifestations of late stage AMD, and higher ceramide (Cer) d18:1/16:0 levels in GA patients. A sensitivity analysis of genetic variants known to be associated with late stage AMD showed that rs1061170 (p.Y402H) in the complement factor H (CFH) gene influences the association of Cer d18:1/16:0 with GA. To understand the possible influence of this genetic variant on ceramide levels, we established a cell-based assay to test the modulation of genes in the ceramide metabolism by factor H-like protein 1 (FHL-1), an alternative splicing variant of CFH that also harbors the 402 residue. We first showed that malondialdehyde-acetaldehyde adducts, an oxidation product commonly found in AMD retinas, induces an increase in ceramide levels in WERI-Rb1 cells in accordance with an increased expression of ceramide synthesis genes. Then, we observed that cells exposed to the non-risk FHL-1:Y402, but not the risk associated variant FHL-1:H402 or full-length CFH, downregulated ceramide synthase 2 and ceramide glucosyltransferase gene expression. Together, our findings show that serum ceramide and hexosylceramide species are altered in AMD patients and that ceramide levels may be influenced by AMD associated risk variants.

C-Reactive Protein as a Therapeutic Target in Age-Related Macular Degeneration

Age-related macular degeneration (AMD), a retinal degenerative disease, is the leading cause of central vision loss among the elderly population in developed countries and an increasing global burden. The major risk is aging, compounded by other environmental factors and association with genetic variants for risk of progression. Although the etiology of AMD is not yet clearly understood, several pathogenic pathways have been proposed, including dysfunction of the retinal pigment epithelium, inflammation, and oxidative stress. The identification of AMD susceptibility genes encoding complement factors and the presence of complement and other inflammatory mediators in drusen, the hallmark deposits of AMD, support the concept that local inflammation and immune-mediated processes play a key role in AMD pathogenesis that may be accelerated through systemic immune activation. In this regard, increased levels of circulating C-reactive protein (CRP) have been associated with higher risk of AMD. Besides being a risk marker for AMD, CRP may also play a role in the progression of the disease as it has been identified in drusen, and we have recently found that its monomeric form (mCRP) induces blood retinal barrier disruption in vitro. In this review, we will address recent evidence that links CRP and AMD pathogenesis, which may open new therapeutic opportunities to prevent the progression of AMD.

Gonadal Hormones and Retinal Disorders: A Review

AIM

Gonadal hormones are essential for reproductive function, but can act on neural and other organ systems, and are probably the cause of the large majority of known sex differences in function and disease. The aim of this review is to provide evidence for this hypothesis in relation to eye disorders and to retinopathies in particular.

METHODS

Epidemiological studies and research articles were reviewed.

RESULTS

Analysis of the biological basis for a relationship between eye diseases and hormones showed that estrogen, androgen, and progesterone receptors are present throughout the eye and that these steroids are locally produced in ocular tissues. Sex hormones can have a neuroprotective action on the retina and modulate ocular blood flow. There are differences between the male and the female retina; moreover, sex hormones can influence the development (or not) of certain disorders. For example, exposure to endogenous estrogens, depending on age at menarche and menopause and number of pregnancies, and exposure to exogenous estrogens, as in hormone replacement therapy and use of oral contraceptives, appear to protect against age-related macular degeneration (both drusenoid and neurovascular types), whereas exogenous testosterone therapy is a risk factor for central serous chorioretinopathy. Macular hole is more common among women than men, particularly in postmenopausal women probably owing to the sudden drop in estrogen production in later middle age. Progestin therapy appears to ameliorate the course of retinitis pigmentosa. Diabetic retinopathy, a complication of diabetes, may be more common among men than women.

CONCLUSION

We observed a correlation between many retinopathies and sex, probably as a result of the protective effect some gonadal hormones may exert against the development of certain disorders. This may have ramifications for the use of hormone therapy in the treatment of eye disease and of retinal disorders in particular.

Review of the association between retinal microvascular characteristics and eye disease

Computerized retinal imaging technologies enable the static and dynamic measurement of a range of retinal microvascular parameters. Large population-based studies have reported associations between these microvascular indices and various ophthalmic diseases including diabetes, age-related macular degeneration, retinal artery embolism, retinal vein occlusion, glaucoma and non-glaucomatous optic neuropathies. Increasingly, sophisticated imaging and analysis techniques have the potential to provide relevant clinical information regarding disease risk and progression; however, further studies are required to verify associations and strengthen the predictive power of these techniques. We summarize the current state of knowledge regarding retinal microvascular characteristics and eye disease.

Neovascular age-related macular degeneration is not associated with coronary heart disease in a Chinese Population: a population-based study

PURPOSE

This case-control study aimed to explore the association between prior coronary heart disease (CHD) and neovascular age-related macular degeneration (AMD) using a population-based data set in Taiwan.

METHODS

We analysed data sourced from the Taiwan Longitudinal Health Insurance Database 2005. The study consisted of 1970 patients with neovascular AMD as cases and 5910 age- and sex-matched controls. We performed a conditional logistic regression to examine the odds ratio (OR) and its corresponding 95% confidence interval (CI) for previously diagnosed CHD between cases and controls.

RESULTS

Of the 7880 sampled patients, 24.5% had a prior history of CHD; CHD was found in 25.7% of cases and in 22.7% of controls (p = 0.008). The conditional logistic regression analysis indicated that the OR for prior CHD for cases was 1.17 [95% confidence interval (CI): 1.04-1.32] compared to the controls. However, after adjusting for patient's monthly income, geographic location, urbanization level, age, hyperlipidaemia, diabetes and hypertension, we failed to observe an association between prior CHD and AMD (OR = 1.03, 95% CI = 0.91-1.17). Additionally, the medical comorbidities of hyperlipidaemia (adjusted OR = 1.29, 95% CI = 1.15-1.45), hypertension (adjusted OR = 1.20, 95% CI = 1.05-1.37) and diabetes (adjusted OR = 1.47, 95% CI = 1.32-1.65) were significantly associated with AMD.

CONCLUSIONS

This study presented no significant difference in the odds of prior CHD between patients with AMD and those without AMD after adjusting for comorbidities and sociodemographic characteristics in a Chinese population.

Early Age-related Macular Degeneration with Cardiovascular and Renal Comorbidities: An Analysis of the National Health and Nutrition Examination Survey, 2005-2008

PURPOSE

A cross sectional study was designed to examine the relationship of early age-related macular degeneration (AMD) with comorbidities of cardiovascular and renal conditions in the representative population using National Health and Nutrition Examination Survey (NHANES), 2005-2008.

METHODS

Participants (≥40 years) who underwent retinal photography were included. Early AMD was defined by the retinal digital images. The comorbidities were self-reported stroke and heart disease (HD), including angina pectoris (AP), coronary heart disease (CHD), congestive heart failure (CHF), and myocardial infarction (MI). Chronic kidney disease (CKD) was determined based on self-report, estimation of glomerular filtration rate (GFR), or the level of urine albumin.

RESULTS

The age-adjusted odds ratio (OR) and 95% CI for having early AMD for persons with the selected conditions were: 2.6 (1.9, 3.6) for any type of HD. When the conditions were considered separately, ORs (95% CIs) were: 2.0 (1.2, 3.4) for AP; 2.5 (1.6, 3.8) for CHD; 2.4 (1.6, 3.6) for MI; 2.3 (1.3, 3.9) for CHF; 3.3 (2.2, 5.0) for stroke; and 2.4 (1.8, 3.2) for CKD. Covariable-adjusted ORs (AOR) were attenuated for all examined conditions, but remained statistically significant. Having any single condition (AOR [95%CI]: 2.7 [1.5, 4.8]) was significantly associated with early AMD, as was having ≥ 2 conditions (AOR [95%CI]: 5.2 [3.0, 9.0]). The strongest association was between early AMD and the combination of HD and stroke (AOR [95% CI]: 6.3 [2.9, 13.8]).

CONCLUSION

Cardiovascular and renal comorbidities are associated with early AMD in a representative sample of the US general population.

Age-Related Macular Degeneration in Patients With Chronic Myeloproliferative Neoplasms

Importance

It has been suggested that systemic inflammation increases the risk of age-related macular degeneration (AMD). Given that chronic immune modulation is present in patients with myeloproliferative neoplasms (MPNs), the risk of AMD in these patients may be increased.

Objective

To compare the risk of AMD in patients with MPNs with the risk of AMD in matched controls from the general population.

Design, Setting, and Participants

A nationwide population-based cohort study using Danish registers was conducted of all patients in Denmark who received a diagnosis between January 1, 1994, and December 31, 2013, of essential thrombocythemia, polycythemia vera, myelofibrosis, or unclassifiable MPNs. For each patient, 10 age- and sex-matched controls were included. All patients without prior AMD were followed up from the date of diagnosis (or corresponding entry date for the controls) until the first AMD diagnosis, death or emigration, or December 31, 2013, whichever occurred first. Data analysis was performed from April 1, 2015, to October 31, 2016.

Main Outcomes and Measures

Incidence of AMD recorded in specialized hospital-based care. The rates and absolute risk of AMD were calculated. Using Cox proportional hazards regression models, smoking and risk-time adjusted hazard ratios (HRs) between patients and controls were calculated. In addition, HRs of neovascular AMD after 2006 were calculated since antivascular endothelial growth factor treatment was introduced nationwide at hospitals thereafter.

Results

A total of 7958 patients with MPNs (4279 women [53.8%] and 3679 men [46.2%]; mean [SD] age at diagnosis, 66.4 [14.3] years) were included in the study. The rate of AMD per 1000 person-years at risk was 5.2 (95% CI, 4.6-5.9) for patients with MPNs (2628 with essential thrombocythemia, 3063 with polycythemia vera, 547 with myelofibrosis, and 1720 with unclassifiable MPNs) and 4.3 (95% CI, 4.1-4.4) for the 77 445 controls, while the 10-year risk of AMD was 2.4% (95% CI, 2.1%-2.8%) for patients with MPNs and 2.3% (95% CI, 2.2%-2.4%) for the controls. The risk of AMD was increased overall for patients with MPNs (adjusted HR, 1.3; 95% CI, 1.1-1.5), with adjusted HRs for the subtypes of 1.2 (95% CI, 1.0-1.6) for essential thrombocythemia, 1.4 (95% CI, 1.2-1.7) for polycythemia vera, 1.7 (95% CI, 0.8-4.0) for myelofibrosis, and 1.5 (95% CI, 1.1-2.1) for unclassifiable MPNs. In addition, patients with MPNs had a higher risk of neovascular AMD (adjusted HR, 1.4; 95% CI, 1.2-1.6).

Conclusions and Relevance

Our results suggest that patients with MPNs are at increased risk of AMD, supporting the possibility that systemic inflammation is involved in the pathogenesis of AMD.