High-sensitivity C-reactive protein, other markers of inflammation, and the incidence of macular degeneration in women

Relationship between Claims-Based Frailty Index and Eye Care Utilization among Medicare Beneficiaries with Glaucoma

PURPOSE

To determine differences in eye care utilization by frailty levels among Medicare beneficiaries with glaucoma.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Medicare fee-for-service beneficiaries over 65 years of age with glaucoma, identified using International Classification of Diseases codes before July 1, 2014.

METHODS

By using a validated claims-based frailty index (range, 0-1), beneficiaries were classified as nonfrail/prefrail (0-0.19), mildly frail (0.20-0.29), and moderate-to-severely frail (≥ 0.30). Negative binomial regression analyses were used to estimate incident rate ratios (IRRs) of eye care utilization by frailty levels between July 1, 2014, and December 31, 2016.

MAIN OUTCOME MEASURES

Current Procedural Terminology codes for eye examinations and eye care-related office visits; eye care-related inpatient and emergency department (ED) encounters; eye care-related nursing facility and home-visit encounters; visual field (VF) and retinal nerve fiber layer (RNFL) OCT tests; and selective laser trabeculoplasties (SLTs) and glaucoma surgeries.

RESULTS

Among 76 260 Medicare beneficiaries with glaucoma, the mean age was 78.9 years (standard deviation, 7.8), female beneficiaries constituted 60.5%, and 78.7% of beneficiaries self-identified as non-Hispanic White. According to a claims-based frailty index, 79.5% of beneficiaries were nonfrail/prefrail, 17.1% were mildly frail, and 3.4% were moderate-to-severely frail. Moderate-to-severely frail beneficiaries were less likely than nonfrail/prefrail beneficiaries to have outpatient encounters (IRR, 0.85, 95% confidence interval [CI], 0.83-0.88); VF tests (IRR, 0.64, 95% CI, 0.60-0.67); RNFL OCT tests (IRR, 0.77, 95% CI, 0.73-0.81); SLT (IRR, 0.74, 95% CI, 0.60-0.92); and glaucoma surgery (IRR, 0.74, 95% CI 0.55-0.99), after adjusting for age, gender, glaucoma severity, race, and socioeconomic status. Compared with nonfrail/prefrail beneficiaries, moderate-to-severely frail beneficiaries had higher rates of inpatient/ED encounters (IRR, 5.03, 95% CI, 2.36-10.71) and nursing facility/home-visit encounters (IRR, 34.89, 95% CI, 14.82-82.13).

CONCLUSIONS

Compared with nonfrail/prefrail Medicare beneficiaries with glaucoma, beneficiaries with moderate-to-severe frailty had lower rates of eye care utilization in the outpatient setting and higher rates of utilization in acute care settings. This suggests that frail patients may receive less disease monitoring and fewer interventions for their glaucoma management.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Etiopathogenesis of non-exudative age-related macular degeneration (literature review)

The article presents an overview of modern publications on epidemiology, risk factors, and the main links of the etiology and pathogenesis of age-related macular degeneration (AMD). The nonexudative or “dry” form of age-related macular degeneration is a multifactorial progressive pathological process caused by hereditary predisposition, general and local disorders of lipid metabolism, negative changes in  the blood supply to the eye, age-related destruction of the Bruch’s membrane and retinal pigment epithelium, the appearance of signs of local and systemic inflammation, the development of oxidative stress with the impact of toxic lipoperoxidation products on the structures of the posterior segment of the eye. Recent studies have discovered new ways of retinal pigment epithelial cell death in response to oxidative stress in AMD, in particular necroptosis, which, in addition to classical apoptosis, is considered the main mechanism of this process. It is noted that the development of AMD may be associated with an age-related decrease in the level of estrogen in women. The analysis of the data on the etiopathogenesis of age-related macular degeneration presented in the modern literature indicates the need for further research and generalization of local and general pathological processes developing in the dynamics of retinal visual function disorders by specialists of various scientific disciplines. 

Synergistic associations of visual and self-reported hearing acuity with low handgrip strength in older adults: a population-based cross-sectional study

BACKGROUND

It is unclear whether visual and hearing acuity are independently or synergistically associated with muscle strength. We aimed to examine the associations of visual and self-reported hearing acuity with low handgrip strength and the additive interaction between visual and hearing acuity on low handgrip strength in people over 60 years.

METHOD

Data of 3,075 individuals aged over 60 years from the 2017 and 2018 Korea National Health and Nutrition Examination Survey were used for this cross-sectional study. Low handgrip strength was defined based on the 20th percentile of the study population (< 30.4 kg for male and < 17.7 kg for female). Visual and self-reported hearing acuity were each divided into three categories: good, moderate, and impaired. Multiple logistic regression and relative excess risk due to interaction (RERI) were performed.

RESULTS

Of the 3,075 participants, 993 (32.3 %) demonstrated low handgrip strength. Low handgrip strength was more prevalent in participants with moderate (adjusted odds ratio [AOR] = 1.54, 95 % confidence interval [CI] = 1.12-2.12) and impaired visual acuity (AOR = 2.00, 95 % CI = 1.34-2.96). Both moderate and impaired self-reported hearing acuity were significantly associated with low handgrip strength (moderate: AOR = 1.25, 95 % CI = 1.01-1.55; impaired: AOR = 1.66, 95 % CI = 1.15-2.38). The more severe the sensory function decline, the higher the association with muscle weakness. Moreover, combined sensory impairments were associated with deteriorating low handgrip strength (AOR = 8.38), with significantly strong additive interactions (RERI = 2.61, 95 % CI = 2.52-2.70).

CONCLUSIONS

Awareness is needed regarding the risk of reduced muscle strength in individuals with moderate and impaired sensory function. Older people with sensory function decline in clinical settings may benefit from programs such as exercise prescription to prevent muscle weakness.

Associations between seven-year C-reactive protein trajectory or pack-years smoked with choroidal or retinal thicknesses in young adults

Inflammation and cigarette smoking predispose to macular diseases, and choroidal and retinal thinning. We explored the choroidal and retinal thicknesses in young adults against their 7-year C-reactive protein (CRP) level trajectory and pack-years smoked. Participants from the Raine study, a longitudinal cohort study, had serum CRP levels analysed at the 14-, 17-, and 20-year follow-ups. Group-based trajectory modelling was used to classify participants according to their 7-year CRP levels. At the 20-year follow-up (at 18–22 years old), participants completed questionnaires on their smoking history, and underwent optical coherence tomography imaging to obtain their choroidal and retinal thicknesses at the macula. Three CRP trajectories were identified: consistently low CRP levels (78% of sample), increasing (11%), or consistently high (11%). 340 and 1035 participants were included in the choroidal and retinal thickness analyses, respectively. Compared to those in the “Low” trajectory group, participants in the “Increasing” and “High” groups had 14–21 μm thinner choroids at most macular regions. Every additional pack-year smoked was linked with a 0.06–0.10 μm thinner retina at the inner and outer macular rings, suggesting a dose-dependent relationship between smoking and thinner retinas. These associations may suggest that an increased risk of future visual impairment or eye disease associated with these risk factors may be present since young adulthood.

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.

Periodontal Diseases and Age-Related Macular Degeneration: Is There a Link? A Review

BACKGROUND

Age-related macular degeneration (AMD) induces irreversible loss of vision in older people. The exact physiopathology remains unclear, but numerous studies highlight the role of inflammation and multiple risk factors. Recent data show an altered periodontal condition subject to AMD. Periodontal diseases lead to the destruction of tooth-supporting tissues, mainly caused by the periodontal infection inducing a chronic inflammation. Periodontal diseases are known to be associated with several extraoral diseases such as diabetes, polyarthritis (rheumatoid arthritis), cardiovascular disease, and preeclampsia.

OBJECTIVES

To assess emerging evidence suggesting an association between periodontitis and AMD.

METHODS

To support this review, we performed a literature search using PubMed, Cochrane, and Google Scholar databases, completed by manual searches in periodontology journals. We included only the original studies published before July 2017 reporting data on periodontal diseases and AMD. No restrictions were made on the language.

RESULTS

Persons with AMD showed more periodontal diseases, fewer teeth, and more alveolar bone loss than those without AMD. Also, a significant association was observed between periodontal diseases and AMD, but only in the youngest individuals studied.

CONCLUSION

According to the studies included in this review, periodontal disease may be a plausible risk factor for AMD and may have a potential role in the earlier stages of this eye disease. Further studies should be encouraged for better understanding of this potential new relationship.

Adverse childhood experiences and neuroinflammatory biomarkers-The role of sex

Despite the growing interest in adverse childhood experiences and biomarkers, less attention has been paid to multiple biomarkers as representing interrelated systems among college students. Guided by the neuroinflammatory pathway hypothesis, the current project takes the initial step in examining the link between three types of childhood adversity and biomarkers of neuroplasticity (brain-derived neurotropic factor [BDNF]) and low-grade inflammation (C-reactive protein [CRP]) in an overarching model and whether this link may differ in men and women. Undergraduate students (n = 85) were recruited through multiple departments from a state university. The participants responded to the detailed online survey questionnaire on childhood adversity and provided one blood sample via venous blood draw. Given that CRP and BDNF represent two interrelated systems, structural equation models were considered the most suitable for the analyses. The findings partially support neural and inflammatory pathways, such that childhood adversity and particularly family dysfunction have a significant positive effect on BDNF (b = 30.41, p < .01). The link between family dysfunction and CRP was stronger in female students (b = 0.57, p < .05). Results suggest that interventions for college students with family dysfunctions may need to target different physiological and behavioral outcomes for male and female students.

Effect of Statins, Metformin, Angiotensin-Converting Enzyme Inhibitors, and Angiotensin II Receptor Blockers on Age-Related Macular Degeneration

PURPOSE

Statins, metformin, angiotensin-converting enzyme (ACE) inhibitors, and angiotensin receptor blockers (ARBs) have been suggested for treating age-related macular degeneration (AMD) due to their pleiotropic effects. Therefore, we investigated whether these drugs prevent AMD.

MATERIALS AND METHODS

We conducted a nested case-control study using the Korean National Health Insurance Service database. Using risk-set sampling of age, sex, cohort entry date, and follow-up duration, we identified incident patients with AMD and 10 matching controls in cohorts with diabetes mellitus or cardiovascular diseases. Exposure was assessed within one year before the index date using patient prescription records. We conducted conditional logistic regression to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) to evaluate the association between cardiovascular medications and AMD.

RESULTS

Our study included 2330 cases and 23278 controls from a cohort of 231274 patients. The ORs (95% CI) for AMD occurrence in users prescribed with statins, metformin, ACE inhibitors, and ARBs were 1.12 (0.94-1.32), 1.15 (0.91-1.45), 0.90 (0.61-1.34), and 1.21 (1.05-1.39), respectively. A duration-response was not observed.

CONCLUSION

Statins, metformin, ACE inhibitors, and ARBs did not inhibit AMD in elderly patients. The absence of a duration-response supports the lack of a causal relationship.

On the origin of proteins in human drusen: The meet, greet and stick hypothesis

Retinal drusen formation is not only a clinical hallmark for the development of age-related macular degeneration (AMD) but also for other disorders, such as Alzheimer's disease and renal diseases. The initiation and growth of drusen is poorly understood. Attention has focused on lipids and minerals, but relatively little is known about the origin of drusen-associated proteins and how they are retained in the space between the basal lamina of the retinal pigment epithelium and the inner collagenous layer space (sub-RPE-BL space). While some authors suggested that drusen proteins are mainly derived from cellular debris from processed photoreceptor outer segments and the RPE, others suggest a choroidal cell or blood origin. Here, we reviewed and supplemented the existing literature on the molecular composition of the retina/choroid complex, to gain a more complete understanding of the sources of proteins in drusen. These "drusenomics" studies showed that a considerable proportion of currently identified drusen proteins is uniquely originating from the blood. A smaller, but still large fraction of drusen proteins comes from both blood and/or RPE. Only a small proportion of drusen proteins is uniquely derived from the photoreceptors or choroid. We next evaluated how drusen components may "meet, greet and stick" to each other and/or to structures like hydroxyapatite spherules to form macroscopic deposits in the sub-RPE-BL space. Finally, we discuss implications of our findings with respect to the previously proposed homology between drusenogenesis in AMD and plaque formation in atherosclerosis.

Recent developments in age-related macular degeneration: a review

Background

Visual impairment in elderly people is a considerable health problem that significantly affects quality of life of millions worldwide. The magnitude of this issue is becoming more evident with an aging population and an increasing number of older individuals.

Objective

The objective of this article was to review the clinical and pathological aspects of age-related macular degeneration (AMD), diagnostic tools, and therapeutic modalities presently available or underway for both atrophic and wet forms of the disease.

Methods

An online review of the PubMed database was performed, searching for the key words. The search was limited to articles published since 1980 to date.

Results

Several risk factors have been linked to AMD, such as age (>60 years), lifestyle (smoking and diet), and family history. Although the pathogenesis of AMD remains unclear, genetic factors have been implicated in the condition. Treatment for atrophic AMD is mainly close observation, coupled with nutritional supplements such as zinc and antioxidants, whereas treatment of wet AMD is based on targeting choroidal neovascular membranes.

Conclusion

Identification of modifiable risk factors would improve the possibilities of preventing the progression of AMD. The role of anti-vascular endothelial growth factor (anti-VEGF) agents has transformed the therapeutic approach of the potentially blinding disease “wet AMD” into a more favorable outcome.

Self-reported vision impairment and incident prefrailty and frailty in English community-dwelling older adults: findings from a 4-year follow-up study

Background

Little is known about vision impairment and frailty in older age. We investigated the relationship of poor vision and incident prefrailty and frailty.

Methods

Cross-sectional and longitudinal analyses with 4-year follow-up of 2836 English community-dwellers aged ≥60 years. Vision impairment was defined as poor self-reported vision. A score of 0 out of the 5 Fried phenotype components was defined as non-frail, 1–2 prefrail and ≥3 as frail. Participants non-frail at baseline were followed-up for incident prefrailty and frailty. Participants prefrail at baseline were followed-up for incident frailty.

Results

49% of participants (n=1396) were non-frail, 42% (n=1178) prefrail and 9% (n=262) frail. At follow-up, there were 367 new cases of prefrailty and frailty among those non-frail at baseline, and 133 new cases of frailty among those prefrail at baseline. In cross-sectional analysis, vision impairment was associated with frailty (age-adjustedandsex-adjusted OR 2.53, 95% CI 1.95 to 3.30). The association remained after further adjustment for wealth, education, cardiovascular disease, diabetes, falls, cognition and depression. In longitudinal analysis, compared with non-frail participants with no vision impairment, non-frail participants with vision impairment had twofold increased risks of prefrailty or frailty at follow-up (OR 2.07, 95% CI 1.32 to 3.24). The association remained after further adjustment. Prefrail participants with vision impairment did not have greater risks of becoming frail at follow-up.

Conclusion

Non-frail older adults who experience poor vision have increased risks of becoming prefrail and frail over 4 years. This is of public health importance as both vision impairment and frailty affect a large number of older adults.

Exploring the cross talk between ER stress and inflammation in age-related macular degeneration

Increasing evidence demonstrates that inflammation and endoplasmic reticulum (ER) stress is implicated in the development and progression of age-related macular degeneration (AMD), a multifactorial neurodegenerative disease. However the cross talk between these cellular mechanisms has not been clearly and fully understood. The present study investigates a possible intersection between ER stress and inflammation in AMD. In this study, we recruited two collections of involved protein markers to retrieve their interaction information from IMEx-curated databases, which are the most well- known protein-protein interaction collections, allowing us to design an intersection network for AMD that is unprecedented. In order to find expression activated subnetworks, we utilized AMD expression profiles in our network. In addition, we studied topological characteristics of the most expressed active subnetworks to identify the hubs. With regard to topological quantifications and expressional activity, we reported a list of the most pivotal hubs which are potentially applicable as probable therapeutic targets. Furthermore, we introduced MAPK signaling pathway as a significantly involved pathway in the association between ER stress and inflammation, leading to promising new directions in discovering AMD formation mechanisms and possible treatments.

Systemic and ocular fluid compounds as potential biomarkers in age-related macular degeneration

Biomarkers can help unravel mechanisms of disease and identify new targets for therapy. They can also be useful in clinical practice for monitoring disease progression, evaluation of treatment efficacy, and risk assessment in multifactorial diseases, such as age-related macular degeneration (AMD). AMD is a highly prevalent progressive retinal disorder for which multiple genetic and environmental risk factors have been described, but the exact etiology is not yet fully understood. Many compounds have been evaluated for their association with AMD. We performed an extensive literature review of all compounds measured in serum, plasma, vitreous, aqueous humor, and urine of AMD patients. Over 3600 articles were screened, resulting in more than 100 different compounds analyzed in AMD studies, involved in neovascularization, immunity, lipid metabolism, extracellular matrix, oxidative stress, diet, hormones, and comorbidities (such as kidney disease). For each compound, we provide a short description of its function and discuss the results of the studies in relation to its usefulness as AMD biomarker. In addition, biomarkers identified by hypothesis-free techniques, including metabolomics, proteomics, and epigenomics, are covered. In summary, compounds belonging to the oxidative stress pathway, the complement system, and lipid metabolism are the most promising biomarker candidates for AMD. We hope that this comprehensive survey of the literature on systemic and ocular fluid compounds as potential biomarkers in AMD will provide a stepping stone for future research and possible implementation in clinical practice.

The association of enzymatic and non-enzymatic antioxidant defense parameters with inflammatory markers in patients with exudative form of age-related macular degeneration

There are evidence that oxidative stress and inflammation are involved in the pathogenesis of the age-related macular degeneration (AMD). The aim of this study was to analyze the antioxidant defense parameters and inflammatory markers in patients with exudative form of AMD (eAMD), their mutual correlations and association with the specific forms of AMD. The cross-sectional study, included 75 patients with the eAMD, 31 patients with the early form, and 87 aged-matched control subjects. Significantly lower SOD, TAS and albumin values and higher GR, CRP and IL-6 were found in the eAMD compared to the early form (p<0.05). Significant negative correlations were found between GPx and fibrinogen (r = -0.254), TAS and IL-6 (r = -0.999) and positive correlations between uric acid and CRP (r = 0.292), IL-6 and uric acid (r = 0.398) in the eAMD. A significant association of CRP (OR: 1.16, 95% CI: 1.03-1.32, p = 0.018), fibrinogen (OR: 2.21, 95% CI: 1.14-4.85, p = 0.021), TAS (OR: 7.45, 95% CI: 3.97-14.35, p = 0.0001), albumin (OR: 1.25, 95% CI: 1.11-1.41, p = 0.0001) and uric acid (OR: 1.006, 95% CI: 1.00-1.02, p = 0.003) was found with the eAMD. In conclusion it may be suggested, there is a significant impairment of antioxidant and inflammatory parameter levels in eAMD patients. In addition, significant association exists between the tested inflammatory markers and antioxidant parameters with late-eAMD.

Serum vascular endothelial growth factor receptor-2 and adropin levels in age-related macular degeneration

AIM

To investigate the serum levels of vascular endothelial growth factor receptor-2 (VEGFR-2) and adropin in age-related macular degeneration (AMD) patients.

METHODS

Ninety-eight AMD patients were included in the study. Seventy-eight age- and sex-matched healthy volunteers were recruited as the control group. Fundus florescein angiography and optical coherence tomography were performed to assess the posterior segment details. Serum VEGFR-2 and adropin levels were measured using enzyme-linked immunosorbent assays and compared between the study groups.

RESULTS

AMD group had significantly increased foveal retinal thickness, serum LDL and HDL levels and significantly decreased subfoveal choroidal thickness (P =0.01, 0.047, 0.025 and <0.001, respectively). Serum VEGFR-2 level revealed a significant decrease in AMD patients compared to controls (26.48±6.44 vs 30.42±7.92 ng/mL, P<0.001). There was an insignificant increase in serum adropin level in AMD patients (6.17±3.19 vs 5.79±2.71 ng/mL, P=0.4). Serum level of VEGFR-2 in AMD patients had a significant negative correlation with foveal retinal thickness (r=-0.226, P=0.025) and a significant positive correlation with subfoveal choroidal thickness (r=0.2, P=0.048).

CONCLUSION

The current study demonstrated that the decreased serum VEGFR-2 level may be considered in the development of AMD. Adropin does not seem to play a role in the pathogenesis of AMD.

Inflammation and its role in age-related macular degeneration

Inflammation is a cellular response to factors that challenge the homeostasis of cells and tissues. Cell-associated and soluble pattern-recognition receptors, e.g. Toll-like receptors, inflammasome receptors, and complement components initiate complex cellular cascades by recognizing or sensing different pathogen and damage-associated molecular patterns, respectively. Cytokines and chemokines represent alarm messages for leukocytes and once activated, these cells travel long distances to targeted inflamed tissues. Although it is a crucial survival mechanism, prolonged inflammation is detrimental and participates in numerous chronic age-related diseases. This article will review the onset of inflammation and link its functions to the pathogenesis of age-related macular degeneration (AMD), which is the leading cause of severe vision loss in aged individuals in the developed countries. In this progressive disease, degeneration of the retinal pigment epithelium (RPE) results in the death of photoreceptors, leading to a loss of central vision. The RPE is prone to oxidative stress, a factor that together with deteriorating functionality, e.g. decreased intracellular recycling and degradation due to attenuated heterophagy/autophagy, induces inflammation. In the early phases, accumulation of intracellular lipofuscin in the RPE and extracellular drusen between RPE cells and Bruch's membrane can be clinically detected. Subsequently, in dry (atrophic) AMD there is geographic atrophy with discrete areas of RPE loss whereas in the wet (exudative) form there is neovascularization penetrating from the choroid to retinal layers. Elevations in levels of local and systemic biomarkers indicate that chronic inflammation is involved in the pathogenesis of both disease forms.

Age-related macular degeneration and polypoidal choroidal vasculopathy in Asians

Age-related macular degeneration (AMD) is the leading cause of irreversible blindness in elderly people globally. It is estimated that there will be more Asians with AMD than the rest of the world combined by 2050. In Asian populations, polypoidal choroidal vasculopathy (PCV) is a common subtype of exudative AMD, while choroidal neovascularization secondary to AMD (CNV-AMD) is the typical subtype in Western populations. The two subtypes share many common clinical features and risk factors, but also have different epidemiological and clinical characteristics, natural history and treatment outcomes that point to distinct pathophysiological processes. Recent research in the fields of genetics, proteomics and imaging has provided further clarification of differences between PCV and CNV-AMD. Importantly, these differences have manifested as disparity in response to intravitreal injections of anti-vascular endothelial growth factor (anti-VEGF) treatment between PCV and CNV-AMD, emphasizing the need for accurate diagnosis of PCV and in distinguishing PCV from CNV-AMD, particularly in Asian patients. Current clinical trials of intravitreal anti-VEGF therapy and photodynamic therapy will provide clearer perspectives of evidence-based management of PCV and may lead to paradigm shifts in therapeutic strategies away from those currently employed in the treatment of CNV-AMD. Further research is needed to clarify the relative contribution of specific pathways in inflammation, complement activation, extracellular matrix dysregulation, lipid metabolism and angiogenesis to the pathogenesis of PCV. Findings from this research, together with improved diagnostic technology and new therapeutics, will facilitate more optimal management of Asian AMD.

The Association of Statin Use with Age-Related Macular Degeneration Progression: The Age-Related Eye Disease Study 2 Report Number 9

PURPOSE

To evaluate the association of statin use with progression of age-related macular degeneration (AMD).

DESIGN

Preplanned, prospective cohort study within a controlled clinical trial of oral supplementation for age-related eye diseases.

PARTICIPANTS

Age-Related Eye Disease Study 2 (AREDS2) participants, aged 50 to 85 years.

METHODS

Factors, including age, gender, smoking status, aspirin use, and history of diabetes, hypertension, heart disease, angina, and stroke-all known to be associated with statin use-were included in a logistic regression model to estimate propensity scores for each participant. Age-adjusted proportional hazards regression models, with and without propensity score matching, were performed to evaluate the association of statin use with progression to late AMD. Analyses adjusting for the competing risk of death were also performed.

MAIN OUTCOME MEASURES

Baseline and annual stereoscopic fundus photographs were assessed centrally by masked graders for the development of late AMD, either neovascular AMD or geographic atrophy (GA).

RESULTS

Of the 3791 participants (2462 with bilateral large drusen and 1329 with unilateral late AMD at baseline), 1659 (43.8%) were statin users. The overall analysis, with no matching of propensity scores and no adjustment for death as a competing risk, showed that statin use was not associated with progression to late AMD (hazard ratio [HR], 1.08; 95% confidence interval [CI], 0.83-1.41; P = 0.56). When matched for propensity scores and adjusted for death as a competing risk, the result was not statistically significant (HR, 0.81; 95% CI, 0.55-1.20; P = 0.29). Furthermore, subgroup analyses of persons with or without late AMD at baseline and the various components of late AMD (neovascular AMD, central GA, or any GA) also showed no statistically significant association of statin use with progression to AMD.

CONCLUSIONS

Statin use was not statistically significantly associated with progression to late AMD in the AREDS2 participants, and these findings are consistent with findings in the majority of previous studies. Statins have been demonstrated to reduce the risk of cardiovascular disease, but our data do not provide evidence of a beneficial effect on slowing AMD progression.

Polypoidal Choroidal Vasculopathy in Asians

Age related macular degeneration (AMD) in Asians has been suggested to differ from their Western counterparts in terms of epidemiology, pathogenesis, clinical presentation and treatment. In particular, polypoidal choroidal vasculopathy (PCV) appears to be the predominant subtype of exudative AMD in Asian populations, in contrast to choroidal neovascularization secondary to AMD (CNV-AMD) in Western populations. Epidemiological data on PCV has been largely limited to hospital-based studies and there are currently no data on the incidence of PCV. Similarities and differences in risk factor profile between PCV and CNV-AMD point to some shared pathogenic mechanisms but also differential underlying mechanisms leading to the development of each phenotype. Serum biomarkers such as CRP, homocysteine and matrix metalloproteinases suggest underlying inflammation, atherosclerosis and deranged extracellular matrix metabolism as possible pathogenic mechanisms. In addition, recent advances in genome sequencing have revealed differences in genetic determinants of each subtype. While the standard of care for CNV-AMD is anti-vascular endothelial growth factor (VEGF) therapy, photodynamic therapy (PDT) has been the mainstay of treatment for PCV, although long-term visual prognosis remains unsatisfactory. The optimal treatment for PCV requires further clarification, particularly with different types of anti-VEGF agents and possible benefits of reduced fluence PDT.

Interactions between C-reactive protein genotypes with markers of nutritional status in relation to inflammation

Inflammation, as indicated by C-reactive protein concentrations (CRP), is a risk factor for chronic diseases. Both genetic and environmental factors affect susceptibility to inflammation. As dietary interventions can influence inflammatory status, we hypothesized that dietary effects could be influenced by interactions with single nucleotide polymorphisms (SNPs) in the CRP gene. We determined 12 CRP SNPs, as well as various nutrition status markers in 2010 black South Africans and analyzed their effect on CRP. Interactions were observed for several genotypes with obesity in determining CRP. Lipid intake modulated the pro-inflammatory effects of some SNPs, i.e., an increase in both saturated fatty acid and monounsaturated fatty acid intake in those homozygous for the polymorphic allele at rs2808630 was associated with a larger increase in CRP. Those harboring the minor alleles at rs3093058 and rs3093062 presented with significantly higher CRP in the presence of increased triglyceride or cholesterol intake. When harboring the minor allele of these SNPs, a high omega-6 to -3 ratio was, however, found to be anti-inflammatory. Carbohydrate intake also modulated CRP SNPs, as HbA1C and fasting glucose levels interacted with some SNPs to influence the CRP. This investigation highlights the impact that nutritional status can have on reducing the inherent genetic susceptibility to a heightened systemic inflammatory state.

Markers of inflammation, oxidative stress, and endothelial dysfunction and the 20-year cumulative incidence of early age-related macular degeneration: the Beaver Dam Eye Study

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

Age-related macular degeneration and the incidence of cardiovascular disease: a systematic review and meta-analysis

IMPORTANCE

Research has indicated some shared pathogenic mechanisms between age-related macular degeneration (AMD) and cardiovascular disease (CVD). However, results from prior epidemiologic studies have been inconsistent as to whether AMD is predictive of future CVD risk.

OBJECTIVE

To systematically review population-based cohort studies of the association between AMD and risk of total CVD and CVD subtypes, coronary heart disease (CHD) and stroke.

DATA SOURCES

A systematic search of the PubMed and EMBASE databases and reference lists of key retrieved articles up to December 20, 2012 without language restriction.

DATA EXTRACTION

Two reviewers independently extracted data on baseline AMD status, risk estimates of CVD and methods used to assess AMD and CVD. We pooled relative risks using random or fixed effects models as appropriate.

RESULTS

Thirteen cohort studies (8 prospective and 5 retrospective studies) with a total of 1,593,390 participants with 155,500 CVD events (92,039 stroke and 62,737 CHD) were included in this meta-analysis. Among all studies, early AMD was associated with a 15% (95% CI, 1.08-1.22) increased risk of total CVD. The relative risk was similar but not significant for late AMD (RR, 1.17; 95% CI, 0.98-1.40). In analyses restricted to the subset of prospective studies, the risk associated with early AMD did not appreciably change; however, there was a marked 66% (95% CI, 1.31-2.10) increased risk of CVD among those with late AMD.

CONCLUSION

Whereas the results from all cohort studies suggest that both early and late AMD are predictive of a small increase in risk of future CVD, subgroup analyses limited to prospective studies demonstrate a markedly increased risk of CVD among people with late AMD. Retrospective studies using healthcare databases may have inherent methodological limitations that obscure such association. Additional prospective studies are needed to further elucidate the associations between AMD and specific CVD outcomes.

Prospective study of common variants in CX3CR1 and risk of macular degeneration: pooled analysis from 5 long-term studies

IMPORTANCE

The CX3CR1 gene is implicated as a candidate gene for age-related macular degeneration (AMD) through several lines of evidence. There is uncertainty, however, as to whether common genetic variants in CX3CR1 alter risk of AMD, since prior studies have been inconsistent and mostly limited to evaluation of 2 nonsynonymous variants, T280M (rs3732378) and V249I (rs3732379).

OBJECTIVE

To determine if common variants in CX3CR1 predict future risk of AMD.

DESIGN, SETTING, AND PARTICIPANTS

Prospective nested case-control study within 5 large study populations with long-term follow-up. We measured genotypes for T280M, V249I, and 13 other common single-nucleotide polymorphisms (SNPs) of the CX3CR1 gene among people who developed AMD (n = 1110, including 369 with neovascular AMD) and 2532 age- and sex-matched controls.

MAIN OUTCOMES AND MEASURES

We determined the incidence rate ratios (RR) and 95% CIs for incidence of AMD for each variant and examined interactions with other AMD-associated variants and modifiable risk factors.

RESULTS

In additive genetic models, we identified nonsignificant associations with AMD for T280M (RR, 0.87; P = .07) and 3 other SNPs, rs2853707 (RR, 0.88; P = .07), rs12636547 (RR, 0.85; P = .10), and rs1877563 (RR, 0.84; P = .06), 1 of which, rs2853707, is positioned in the CX3CR1 promoter region and was associated with neovascular AMD (RR, 0.75; P = .03). We observed that a recessive model was a better fit to the data for some SNPs, with associations between rs11715522 and AMD (RR, 1.27; P = .03) and between rs2669845 (RR, 3.10; P = .04), rs2853707 (RR, 0.48; P = .050), and rs9868689 (RR, 0.31; P = .02) and neovascular AMD. Moreover, in exploratory analyses, we identified a number of possible interactions including between V249I and rs2669845 and dietary intake of ω-3 fatty acids (P = .004 and P = .009, respectively) for AMD; between rs2669845 and obesity (P = .03) for neovascular AMD; between T280M and complement component 3 (C3) R102G for AMD (P = .03); between rs2669845 and Y402H in complement factor H for AMD (P = .04); and between rs2669845, rs2853707, and V249I and C3 R102G for neovascular AMD (P = .008; .04; and .002, respectively).

CONCLUSIONS AND RELEVANCE

This study failed to identify significant associations between common CX3CR1 variants and AMD after considering the number of SNPs analyzed and multiple comparisons. However, we observed evidence consistent with recessive modes of association and that an effect of CX3CR1 variants may depend on other factors including dietary intake of ω-3 fatty acids, obesity, and genotypes at CFH Y402H and C3 R102G. If replicated in other populations, these findings would support a role for CX3CR1 in AMD but also suggest that its role may involve mechanisms that are independent of the T280M/V249I variations.

Impairment of the ubiquitin-proteasome pathway in RPE alters the expression of inflammation related genes

The ubiquitin-proteasome pathway (UPP) plays an important role in regulating gene expression. Retinal pigment epithelial cells (RPE) are a major source of ocular inflammatory cytokines. In this work we determined the relationship between impairment of the UPP and expression of inflammation-related factors. The UPP could be impaired by oxidative stress or chemical inhibition. Impairment of the UPP in RPE increased the expression of several inflammatory cytokines, such as IL-6 and IL-8. However, the expression of monocyte chemoattractant protein-1 (MCP-1) and complement factor H (CFH) and was reduced upon impairment of the UPP. These data suggest that impairment of the UPP in RPE may be one of the causes of retinal inflammation and abnormal functions of monocyte and the complement system during the pathogenesis of age-related macular degeneration.

Nature and nurture- genes and environment- predict onset and progression of macular degeneration

Age-related macular degeneration (AMD) is a common cause of irreversible visual loss and the disease burden is rising world-wide as the population ages. Both environmental and genetic factors contribute to the development of this disease. Among environmental factors, smoking, obesity and dietary factors including antioxidants and dietary fat intake influence onset and progression of AMD. There are also several lines of evidence that link cardiovascular, immune and inflammatory biomarkers to AMD. The genetic etiology of AMD has been and continues to be an intense and fruitful area of investigation. Genome-wide association studies have revealed numerous common variants associated with AMD and sequencing is increasing our knowledge of how rare genetic variants strongly impact disease. Evidence for interactions between environmental, therapeutic and genetic factors is emerging and elucidating the mechanisms of this interplay remains a major challenge in the field. Genotype-phenotype associations are evolving. The knowledge of non-genetic, modifiable risk factors along with information about heritability and genetic risk variants for this disease acquired over the past 25 years have greatly improved patient management and our ability to predict which patients will develop or progress to advanced forms of AMD. Personalized medicine and individualized prevention and treatment strategies may become a reality in the near future.

The Relationship between Neovascular Age-Related Macular Degeneration and Erectile Dysfunction

Purpose. To evaluate association between erectile dysfunction (ED) and neovascular age-related macular degeneration (AMD). Methods. 195 men enrolled in this cross-sectional study. 90 of them had neovascular AMD and 105 of them were healthy volunteers. The International Index of Erectile Function (IIEF) questionnaire's erectile function (EF) domain was used to assess ED. The patients in the study and control groups were statistically compared according to visual acuity, EF score, and body mass index. Results. The mean ages were 62 (54.5–73) and 60 (54–68), in the neovascular AMD and control groups, respectively. The total EF scores were 9 (6–16) in neovascular AMD and 18 (9.5–27) in control group. The results of IIEF questionnaire on neovascular AMD patients revealed that 85 men (94.4%) had some degree of ED, whereas 68 men (64.8%) had some degree of ED on control group. Patients with neovascular AMD had a significantly higher incidence of ED than control patients (P < 0.01). There was a significant association between ED and neovascular AMD (P < 0.01). Conclusions. Our results suggested that neovascular AMD has a high association with ED.

Rationale and design of the Cardiovascular Inflammation Reduction Trial: a test of the inflammatory hypothesis of atherothrombosis

BACKGROUND

Inflammation plays a fundamental role in atherothrombosis. Yet, whether direct inhibition of inflammation will reduce the occurrence of adverse cardiovascular outcomes is not known.

DESIGN

The Cardiovascular Inflammation Reduction Trial (CIRT) (ClinicalTrials.govNCT01594333) will randomly allocate 7,000 patients with prior myocardial infarction (MI) and either type 2 diabetes or the metabolic syndrome to low-dose methotrexate (target dose 15-20 mg/wk) or placebo over an average follow-up period of 3 to 5 years. Low-dose methotrexate is a commonly used anti-inflammatory regimen for the treatment of rheumatoid arthritis and lacks significant effects on lipid levels, blood pressure, or platelet function. Both observational and mechanistic studies suggest that low-dose methotrexate has clinically relevant antiatherothrombotic effects. The CIRT primary end point is a composite of nonfatal MI, nonfatal stroke, and cardiovascular death. Secondary end points are all-cause mortality, coronary revascularization plus the primary end point, hospitalization for congestive heart failure plus the primary end point, all-cause mortality plus coronary revascularization plus congestive heart failure plus the primary end point, incident type 2 diabetes, and net clinical benefit or harm. CIRT will use standardized central methodology designed to ensure consistent performance of all dose adjustments and safety interventions at each clinical site in a manner that protects the blinding to treatment but maintains safety for enrolled participants.

SUMMARY

CIRT aims to test the inflammatory hypothesis of atherothrombosis in patients with prior MI and either type 2 diabetes or metabolic syndrome, conditions associated with persistent inflammation. If low-dose methotrexate reduces cardiovascular events, CIRT would provide a novel therapeutic approach for the secondary prevention of heart attack, stroke, and cardiovascular death.

C-reactive protein and the incidence of macular degeneration: pooled analysis of 5 cohorts

IMPORTANCE

This study adds to the evidence that elevated levels of high-sensitivity C-reactive protein (hsCRP) predict future risk of age-related macular degeneration (AMD). This information might shed light on underlying pathological mechanisms involving inflammation and could be of clinical utility in the identification of persons at high risk of AMD who may benefit from increased adherence to lifestyle recommendations, eye examination schedules, and therapeutic protocols.

OBJECTIVE

To investigate the relationship between hsCRP and future risk of AMD in US men and women.

DESIGN

Pooled analysis of prospective nested case-control data from the Women's Health Study and 4 other cohorts, the Physicians' Health Study, Women's Antioxidant and Folic Acid Cardiovascular Study, Nurses' Health Study, and Health Professionals Follow-up Study.

SETTING

A prospective nested case-control study within 5 large cohorts.

PARTICIPANTS

Patients were initially free of AMD. We prospectively identified 647 incident cases of AMD and selected age- and sex-matched controls for each AMD case (2 controls for each case with dry AMD or 3 controls for each case of neovascular AMD). MAIN OUTCOME MEASURES We measured hsCRP in baseline blood samples. We used conditional logistic regression models to examine the relationship between hsCRP and AMD and pooled findings using meta-analytic techniques.

RESULTS

After adjusting for cigarette smoking status, participants with high (>3 mg/L) compared with low (<1 mg/L) hsCRP levels had cohort-specific odds ratios (ORs) for incident AMD ranging from 0.94 (95% CI, 0.58-1.51) in the Physicians' Health Study to 2.59 (95% CI, 0.58-11.67) in the Women's Antioxidant and Folic Acid Cardiovascular Study. After testing for heterogeneity between studies (Q = 5.61; P = .23), we pooled findings across cohorts and observed a significantly increased risk of incident AMD for high vs low hsCRP levels (OR, 1.49; 95% CI, 1.06-2.08). Risk of neovascular AMD was also increased among those with high hsCRP levels (OR, 1.84; 95% CI, 1.14-2.98).

CONCLUSIONS AND RELEVANCE

Overall, these pooled findings from 5 prospective cohorts add further evidence that elevated levels of hsCRP predict greater future risk of AMD. This information might shed light on underlying mechanisms and could be of clinical utility in the identification of persons at high risk of AMD who may benefit from increased adherence to lifestyle recommendations, eye examination schedules, and therapeutic protocols.

Inflammatory cytokines protect retinal pigment epithelial cells from oxidative stress-induced death

Purpose

To investigate the effects of inflammatory factors and oxidative stress on cell survival of the human retinal pigment epithelial (RPE) cell line, ARPE-19.

Methods

Confluent RPE cells were treated with peripheral blood mononuclear cells-conditioned medium (PCM), H₂O₂, NaIO₃, interferon (IFN)-γ, tumor necrosis factor (TNF)-α, or combinations of these. Cell viability was determined by viability assays and by light microscopy. Effector molecules of cell death were investigated by immunofluorescence microscopy and flow cytometry. Microarrays were performed to screen for differential expression of anti-oxidative enzymes, and protein expression was validated by immunoblotting.

Results

Viability of RPE cells was reduced by exposure to inflammatory agents (PCM, IFNγ+/-TNFα) or to oxidative agents (H₂O₂ or NaIO₃). Unexpectedly, cells treated with either H₂O₂ or NaIO₃ were partially protected from cell death by the addition of PCM. This protection was conferred, at least in part, by IFNγ and TNFα. Cell death induced by H₂O₂ or NaIO₃ was preceded by mitochondrial dysfunction and by p62 upregulation, both of which were attenuated by PCM and/or by IFNγ+TNFα. RPE cells co-cultured with activated T cells, or treated with cytokines showed increased expression of anti-oxidative genes, with upregulation of superoxide dismutase 2 protein following PCM treatment.

Conclusion

Oxidative stress-induced cell death was reduced by concomitant inflammatory stress. This is likely due to the cytokine-mediated induction of the anti-oxidative stress response, upregulating protective anti-oxidant pathway(s). These findings suggest caution for the clinical use of anti-inflammatory agents in the management of immune-associated eye diseases such as age-related macular degeneration.

Alterations of choroidal blood flow regulation in young healthy subjects with complement factor H polymorphism

A common polymorphism in the complement factor H gene (rs1061170, Y402H) is associated with a high risk of age-related macular degeneration (AMD). In the present study we hypothesized that healthy young subjects homozygous for the high-risk haplotype (CC) show abnormal choroidal blood flow (ChBF) regulation decades before potentially developing the disease. A total of 100 healthy young subjects were included in the present study, of which 4 subjects were excluded due to problems with genotyping or blood flow measurements. ChBF was measured continuously using laser Doppler flowmetry while the subjects performed isometric exercise (squatting) for 6 minutes. The increase in ChBF was less pronounced than the response in ocular perfusion pressure (OPP), indicating for some degree of choroidal blood flow regulation. Eighteen subjects were homozygous for C, 47 subjects were homozygous for T and 31 subjects were heterozygous (CT). The increase in OPP during isometric exercise was not different between groups. By contrast the increase in ChBF was more pronounced in subjects homozygous for the high risk C allele (p = 0.041). This was also evident from the pressure/flow relationship, where the increase in ChBF in homozygous C carriers started at lower OPPs as compared to the other groups. Our data indicate that the regulation of ChBF is abnormal in rs1061170 CC carriers. So far this polymorphism has been linked to age related macular degeneration (AMD) mainly via inflammatory pathways associated with the complement system dysfunction. Our results indicate that it could also be related to vascular factors that have been implicated in AMD pathogenesis.

Complement system activation and endothelial dysfunction in patients with age-related macular degeneration (AMD): possible relationship between AMD and atherosclerosis

Age-related macular degeneration (AMD) shares several pathological and epidemiological similarities with systemic atherosclerosis (AS). First, an association between AS and AMD is apparent from the analyses of the histological and biochemical structure of atherosclerotic plaques in the vascular walls and retinal drusen, the hallmark of AMD. Second, there is considerable evidence implicating endothelial dysfunction in the pathogenesis of both disorders, and cellular oxidative stress appears to be a common denominator underlying this process. Moreover, there are observations that the complement system (CS) triggering inflammatory response contributes to the onset and advancement of both diseases. The CS plays a role in the generation of drusen and neovascularization in AMD as well as in vascular endothelium activation, cell damage and ultimately atherosclerotic plaque formation in the course of systemic arteriosclerosis. It is widely recognized that both AMD and AS are not only related to local stimulation of the CS, but also result in its systemic activation. In addition, a specific Y402H polymorphism of the complement inhibitor factor H has been found to be associated with the incidence of both AMD and AS. Here, we propose a linking hypothesis between CS activation, endothelial dysfunction and the pathogenesis of two common and age-related pathological processes, AS and AMD. We also discuss the potential therapeutic value of pharmacological modulation of CS activation in these disorders.

Lutein and zeaxanthin supplementation reduces photooxidative damage and modulates the expression of inflammation-related genes in retinal pigment epithelial cells

Oxidative damage and inflammation are related to the pathogenesis of age-related macular degeneration (AMD). Epidemiologic studies suggest that insufficient dietary lutein and zeaxanthin intake or lower serum zeaxanthin levels are associated with increased risk for AMD. The objective of this work is to test the protective effects of lutein and zeaxanthin against photooxidative damage to retinal pigment epithelial cells (RPE) and oxidation-induced changes in expression of inflammation-related genes. To mimic lipofuscin-mediated photooxidation in vivo, we used ARPE-19 cells that accumulated A2E, a lipofuscin fluorophore and photosensitizer, as a model system to investigate the effects of lutein and zeaxanthin supplementation. The data show that supplementation with lutein or zeaxanthin in the medium resulted in accumulation of lutein or zeaxanthin in the RPE cells. The concentrations of lutein and zeaxanthin in the cells were 2- to 14-fold of that detected in the medium, indicating that ARPE-19 cells actively take up lutein or zeaxanthin. As compared with untreated cells, exposure of A2E-containing RPE to blue light resulted in a 40-60% decrease in proteasome activity, a 50-80% decrease in expression of CFH and MCP-1, and an~20-fold increase in expression of IL-8. The photooxidation-induced changes in expression of MCP-1, IL-8, and CFH were similar to those caused by chemical inhibition of the proteasome, suggesting that inactivation of the proteasome is involved in the photooxidation-induced alteration in expression of these inflammation-related genes. Incubation of the A2E-containing RPE with lutein or zeaxanthin prior to blue light exposure significantly attenuated the photooxidation-induced inactivation of the proteasome and photooxidation-induced changes in expression of MCP-1, IL-8, and CFH. Together, these data indicate that lutein or zeaxanthin modulates inflammatory responses in cultured RPE in response to photooxidation. Protecting the proteasome from oxidative inactivation appears to be one of the mechanisms by which lutein and zeaxanthin modulate the inflammatory response. Similar mechanisms may explain salutary effects of lutein and zeaxanthin in reducing the risk for AMD.

The role of CRP and inflammation in the pathogenesis of age-related macular degeneration

Age-related macular degeneration (AMD) is a complex, degenerative and progressive disease involving the multiple genetic and environmental factors that can result in severe visual loss. The etiology of AMD is not well understood. Many theories exist and feature mechanisms of oxidative stress, atherosclerotic-like changes, genetic predisposition and inflammation. The most recent clinical studies appointed to a great role of inflammation and C-reactive protein (CRP) in the pathogenesis of AMD. There is a large body of evidence indicating the association of CRP with endothelial dysfunction, oxidative stress and production of reactive oxygen species (ROS), as well as with lipid status disorder in AMD patients. According to recent studies, CRP is definitely not only the inflammatory marker but also a mediator of development of the vascular disorders in the retinal circulation. The results obtained from the present studies may help our understanding the pathogenesis of the retinal vascular disease associated with high levels of CRP.

Regulation of VEGF expression in human retinal cells by cytokines: implications for the role of inflammation in age-related macular degeneration

Chronic inflammation is implicated in the pathogenesis of age-related macular degeneration (AMD). Choroidal neovascularization (CNV) observed in exudative form of AMD results in vision loss. Human retinal pigment epithelial cell (HRPE) layer and choroidal tissue are the primary pathological sites in AMD. Pathological and therapeutic evidences have strongly indicated the vascular endothelial growth factor (VEGF) molecules as critical components in CNV pathogenesis. In these studies, we used human primary HRPE and choroidal fibroblast cells (HCHF) prepared from adult donor eyes. The effects of inflammatory cytokine (IFN-γ+ TNF-α+IL-1β) mix (ICM) on global gene expression profiles in HRPE cells, revealed 10- and 9-fold increase in VEGF-A and VEGF-C expression, respectively. The microarray results were validated by quantitative RT-PCR and secretion of VEGFs proteins. IL-1β is the most potent in inducing VEGFs secretion followed by IFN-γ and TNF-α, and the secretion was more effective in the presence of 2 and 3 cytokines. NF-κB and JAK-STAT pathway, but not HIF-1α, Sp-1, Sp-3, and STAT-3, transcription factors were upregulated and translocated to nucleus by ICM treatment. The mRNA levels of VEGF-A and VEGF-C and secretion of these proteins were also significantly enhanced by ICM in HCHF cells. The secretion of other angiogenic molecules, PEDF, SDF-1α, endostatin, and angiopoietins was not affected by ICM. Our results show that the inflammatory cytokines enhance secretion of VEGF-A and VEGF-C by HRPE and HCHF cells. These studies indicate that VEGFs secreted by these cells initiate and promote pathological choroidal and retinal noevascularization processes in AMD.

The influence of genetics on response to treatment with ranibizumab (Lucentis) for age-related macular degeneration: the Lucentis Genotype Study (an American Ophthalmological Society thesis)

PURPOSE

Age-related macular degeneration (AMD) has a complex etiology arising from genetic and environmental influences. This past decade have seen several genes associated with the disease. Variants in five genes have been confirmed to play a major role. The objective of this study was to evaluate whether genes influence treatment response to ranibizumab for neovascular AMD. The hypothesis was that an individual's genetic variation will determine treatment response.

METHODS

The study was a two-site prospective open-label observational study of patients newly diagnosed with exudative (neovascular) AMD receiving intravitreal ranibizumab therapy. Treatment-naïve patients were enrolled at presentation and received monthly "as needed" therapy. Clinical data was collected monthly and DNA extracted. Genotyping was performed using the Illumina (San Diego, California) 660-Quad single-nucleotide polymorphism (SNP) chip. Regression analyses were performed to identify SNPs associated with treatment-response end points.

RESULTS

Sixty-five patients were enrolled. No serious adverse events were recorded. The primary outcome measure was change in ETDRS visual acuity at 12 months. A SNP in the CFH gene was found to be associated with less improvement in visual acuity while receiving ranibizumab therapy. The C3 gene, among others, was associated with reduced thickening and improved retinal architecture. VEGFA, FLT1, and CFH were associated with requiring fewer ranibizumab injections over the 12-month study.

CONCLUSIONS

This study is one of the first prospective pharmacogenetic study of intravitreal ranibizumab. Although preliminary, the results identify a number of putative genetic variants, which will be further examined by replication and functional studies to elucidate the complete pharmacogenetic architecture of therapy for AMD.

Statin use and the risk of age related macular degeneration in a large health organization in Israel

OBJECTIVE

To investigate the association between persistent use of statins and the risk of age-related macular degeneration (AMD).

DESIGN

A population-based retrospective cohort among adults who began statin therapy between 1998 and 2006 in a large health organization in Israel. The organization's central computerized databases were used to collect data on incident AMD cases diagnosed by ophthalmologists.

RESULTS

A total of 108,973 individuals aged 55 or older were identified. During the study follow-up period 409,113 person-years, there were 2,732 incident AMD cases (6.68 per 1,000 person-years). The crude incidence density rate of AMD among patients at the lowest quintile of persistence with statins (7.18 per 1,000) was comparable to that of highest persistence quintile (7.13 per 1,000). After adjustment for potential confounders, patients in the highest quintile of persistence with statins had a hazard ratio of 0.99 (95% Confidence Interval: 0.78-1.26) for AMD compared with patients in the lowest proportion of days covered (PDC) quintile. In addition to age, AMD was found to associate with past smoking, asthma, diabetes and frequent visits to ophthalmologists or primary physicians prior to index date.

CONCLUSIONS

Our study agrees with previous studies that showed no association between persistent use of statins and reduced risk of AMD. These results suggest that the early reports on a strong protective effect of statins against AMD development were probably a result of a small study effect.

The prevalence and analysis of risk factors for age-related macular degeneration: 18-year follow-up data from the Speedwell eye study, United Kingdom

AIMS/PURPOSE

To determine the prevalence of age-related maculopathy (ARM) and age-related macular degeneration (AMD) in men aged 65-83 years living in the Speedwell region of Bristol, United Kingdom and identify modifiable risk factors.

METHODS

A total of 2348 men recruited to the Speedwell prospective cohort study in 1979 were followed up in 1997 with an eye questionnaire and had retinal photographs that were assessed using the International Classification System for ARM.

RESULTS

In all, 934 men (66.8% response rate) attended with a mean of 17.9 years (15.3-20.6 years) follow-up. Early ARM (grades 2-3) was found in 9.2% (95% confidence interval (CI) 7.4%, 11.4%) and late age-related maculopathy (grade 4, AMD) in 0.5% (95% CI 0.2%, 1.2%). The risk of ARM (grades 2-4) was increased with raised C-reactive protein and consumption of lard and solid fats, whereas triglyceride levels were associated with a lower risk. The latter were confirmed in multivariable analyses and in addition, haemodynamic measures also predicted risk (eg mean arterial pressure odds ratio (OR) per z-score 1.37, 95% CI 1.04, 1.79).

CONCLUSIONS

In a representative cohort of men aged 65-83 from Bristol, United Kingdom, many had macular changes that put them at higher risk of developing AMD. Various modifiable exposures were associated with an increased risk ARM/AMD. Opportunities for screening and undertaking secondary prevention interventions need to be explored to prevent progression of the disease and blindness.

A review and meta-analysis of the association between C-reactive protein and age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of blindness in people over 60 in western countries. Inflammatory markers have been implicated in the development and progression of AMD. C-reactive protein (CRP) is an inflammatory marker known to be associated with cardiovascular disease, and a link between AMD and CRP has been suggested. In this systematic review we summarize the currently available evidence from clinic-based and population-based studies investigating this association. A meta-analysis of evidence from eleven studies (41,690 study participants) shows that high serum levels (>3 mg/L) of CRP are associated with a two-fold likelihood of late onset AMD, compared to low levels (<1mg/L). Sub-group meta-analyses show a higher association in studies using ophthalmoscopic examination, compared to those using photographic grading (pooled odds ratio 3.83 vs 1.36), to determine AMD status, or in clinic-based samples compared to population-based studies.

The association of lipoprotein parameters and C-reactive protein in patients with age-related macular degeneration

BACKGROUND

Age-related macular degeneration (AMD) is the most common cause of visual impairment in individuals over 50 years of age, with the prevalence of 0.05% before the age of 50 rising to 30% after 74 years of age. An elevated concentration of plasma lipoproteins is considered to be one of the risk factors of AMD development. The aim of our study was to analyze the concentration of serum lipoproteins - total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), non-LDL cholesterol and triglycerides - as well as apolipoproteins - apoA1, apoB and Lp(a) - along with C-reactive protein (CRP) in patients with AMD in order to explore the possible association of lipid and inflammatory parameters with the pathogenesis of AMD.

MATERIAL AND METHODS

In the cross-sectional study in the University clinical setting, 79 patients with AMD, aged 71.47 ± 7.02 years, and 84 aged-matched control subjects were included. The patients underwent complete ophthalmological examination including visual acuity assessment, color fundus photography and fluorescein angiography.

RESULTS

Statistical processing data revealed significantly higher total (p = 0.0002), LDL (p = 0.023), non-HDL cholesterol (p = 0.0014) and CRP (p = 0.049) values in AMD patients compared to control subjects.

CONCLUSIONS

Based on the obtained results, it may be concluded that lipid status disorder and inflammation could play an important role in the development of AMD in elderly people.

Retinal pigment epithelial cells upregulate expression of complement factors after co-culture with activated T cells

In this study we examined the effect of T cell-derived cytokines on retinal pigment epithelial (RPE) cells with respect to expression of complement components. We used an in vitro co-culture system in which CD3/CD28-activated human T cells were separated from the human RPE cell line (ARPE-19) by a membrane. Differential gene expression in the RPE cells of complement factor genes was identified using gene arrays, and selected gene transcripts were validated by q-RT-PCR. Protein expression was determined by ELISA and immunoblotting. Co-culture with activated T cells increased RPE mRNA and/or protein expression of complement components C3, factors B, H, H-like 1, CD46, CD55, CD59, and clusterin, in a dose-dependent manner. Soluble factors derived from activated T cells are capable of increasing expression of complement components in RPE cells. This is important for the further understanding of inflammatory ocular diseases such as uveitis and age-related macular degeneration.

Prospective study of common variants in the retinoic acid receptor-related orphan receptor α gene and risk of neovascular age-related macular degeneration

OBJECTIVES

The retinoic acid receptor (RAR)-related orphan receptor α gene (RORA) is implicated as a candidate for age-related macular degeneration (AMD) through a previous microarray expression study, linkage data, biological plausibility, and 2 clinic-based cross-sectional studies. We aimed to determine if common variants in RORA predict future risk of neovascular AMD.

METHODS

We measured genotypes for 18 variants in intron 1 of the RORA gene among 164 cases who developed neovascular AMD and 485 age- and sex-matched controls in a prospective, nested, case-control study within the Nurses' Health Study and the Health Professionals Follow-up Study. We determined the incidence rate ratios and 95% confidence intervals (CI) for neovascular AMD for each variant and examined interactions with other AMD-associated variants and modifiable risk factors.

RESULTS

We identified one single-nucleotide polymorphism (rs12900948) that was significantly associated with increased incidence of neovascular AMD. Participants with 1 and 2 copies of the G allele were 1.73 (CI, 1.32-2.27) and 2.99 (CI, 1.74-5.14) times more likely to develop neovascular AMD. Individuals homozygous for both the G allele of rs12900948 and ARMS2 A69S had a 40.8-fold increased risk of neovascular AMD (CI, 10.1-164; P = .017). Cigarette smokers who carried 2 copies of the G allele had a 9.89-fold risk of neovascular AMD but the interaction was not significant (P = .08). We identified a significant AMD-associated haplotype block containing the single-nucleotide polymorphisms rs730754, rs8034864, and rs12900948, with P values for ACA = 1.16 × 10(-9), ACG = 5.85 × 10(-12), and GAA = .0001 when compared with all other haplotypes.

CONCLUSIONS

Common variants and haplotypes within the RORA gene appear to act synergistically with the ARMS2 A69S polymorphism to increase risk of neovascular AMD. These data add further evidence of a high level of complexity linking genetic and modifiable risk factors to AMD development and should help efforts at risk prediction.

C-reactive protein and CFH, ARMS2/HTRA1 gene variants are independently associated with risk of macular degeneration

PURPOSE

Genetic variants CFH and ARMS2/HTRA1 gene regions as well as high-sensitivity C-reactive protein (CRP) levels are related to age-related macular degeneration (AMD). We evaluated their independent and combined effects on risk of AMD, as well as their interactions.

DESIGN

Case-control study.

PARTICIPANTS

Subjects with AMD (n = 244) or no or minimal maculopathy (n = 209) in the Age Related Eye Disease Ancillary Study.

METHODS

Risk factors, genotypes, and biomarkers were assessed by questionnaire, direct measurement, and analyses of blood specimens. The independent and joint effects of serum CRP and CFH (rs1061170) and ARMS2/HTRA1 (rs10490924) genotypes were assessed using logistic regression analyses, adjusting for age, gender, education, smoking, body mass index, and vitamin/mineral supplementation.

MAIN OUTCOME MEASURES

We defined AMD as large drusen, geographic atrophy, or neovascular disease.

RESULTS

Higher CRP levels were associated with a higher risk of AMD, controlling for genotype and demographic and behavioral risk factors, with odds ratio 2.6 for levels of 3.0 mg/L and above versus below 1.0 mg/L (95% confidence interval, 1.01-6.7). Single nucleotide polymorphisms (SNPs) in both genes were also independently associated with risk of AMD, controlling for the level of CRP and other factors. Presence of both highest level of CRP together with risk genotypes for both SNPs, conferred the highest risk of AMD (OR 5.4, 95% CI 1.4-21.1).

CONCLUSIONS

High-sensitivity CRP and polymorphisms in the CFH and ARMS2/HTRA1 genes are independently associated with risk of AMD. Higher CRP level tends to confer a higher risk of AMD within most genotype groups.

C-reactive protein levels and complement factor H polymorphism interaction in age-related macular degeneration and its progression

PURPOSE

To determine the effect of elevated level of C-reactive protein (CRP) and its joint effect with the complement factor H (CFH) polymorphism on prevalent age-related macular degeneration (AMD) and its progression.

DESIGN

Two-arm case-control study: (a) Study on prevalent AMD cases and population-based controls; (b) longitudinal study on AMD progression, comparing those in whom AMD progressed with those with no progression.

PARTICIPANTS

(a) A cross-sectional sample of 544 participants, of whom 312 had features of early or late AMD and 232 were controls; (b) a sample of 254 early AMD cases, followed for 7 years.

METHODS

The study was conducted in Melbourne, Australia. Macular stereo photographs were graded for AMD according to the International Classification and Grading System. High-sensitivity CRP was measured in fresh serum, and genotyping was performed through the Australian Genome Research Facility. The association of CRP with outcomes was tested using multivariate logistic regression analysis adjusted for age, smoking, anti-inflammatory medications, and the CC genotype of the CFH gene. Risk factor interaction was explored using an additive model.

MAIN OUTCOME MEASURES

Prevalent early AMD, prevalent late AMD, progressed AMD, and measures of risk factor interaction.

RESULTS

Elevated CRP levels were associated with late AMD: odds ratio (OR), 3.12; 95% confidence interval (CI), 1.38-7.07. An association of elevated CRP with AMD progression was weaker: OR, 1.90 (95% CI, 0.88-4.10). A combination of elevated CRP and the CC (Y402H) genotype resulted in a super-additivity of the risks, with odds ratios of 19.3 (95% CI, 2.8-134) for late AMD, and 6.8 (95% CI, 1.2-38.8) for AMD progression, with the attributable proportion of risk owing to CRP-CFH interaction calculated at 26% for prevalent late AMD and 22% for AMD progression.

CONCLUSIONS

Synergistic influence of CRP levels and the at risk genotype of the CFH gene resulted in a super-additive risk for prevalent late AMD and AMD progression. Testing for the combination of these 2 risk factors to predict a high risk of AMD and its progression would allow for targeted trials of new intervention strategies.

A population-based assessment of blood lead levels in relation to inflammation

BACKGROUND

Some experimental and observational research suggests that inflammation may be an important mediator of lead toxicity. However, lead-induced inflammation has not been well-studied in non-occupationally exposed populations.

METHODS

Using data for 9,145 individuals >or=40 years of age from the National Health and Nutrition Examination Survey 1999-2004, we assessed the association between blood lead levels (BLLs) and C-reactive protein (CRP), fibrinogen, and white blood cell (WBC) count via ordinal logistic regression. We also examined the interaction between BLL and gender in relation to the inflammatory markers.

RESULTS

No evidence for an association between lead exposure and inflammatory markers was observed with odds ratios around or below the null. Although men but not women appeared to be at increased risk of lead-induced inflammation, no consistent dose-response patterns were observed across BLL quintiles.

CONCLUSION

Inflammation does not appear to be an important mediator of lead toxicity.

Effects of vitrectomy on age-related macular degeneration

PURPOSE

To determine whether vitrectomy alters the long-term progression of age-related macular degeneration (AMD).

DESIGN

Retrospective case-control study.

PARTICIPANTS

Forty-four eyes of 22 patients with AMD who underwent vitrectomy in 1 eye were included in the study. The progression of AMD at follow-up in the 22 eyes that underwent vitrectomy was compared with the 22 fellow, nonvitrectomized eyes.

METHODS

The charts and photographs of subjects with Age-Related Eye Disease Study category 3 AMD in both eyes who previously underwent vitrectomy surgery for an epiretinal membrane or macular hole were reviewed. Subjects were excluded if they had had a vitrectomy in both eyes, had <2 years of follow-up, had previous choroidal neovascularization (CNV), retinal detachment, diabetic retinopathy, angioid streaks, high myopia, vascular occlusions, or extensive macular scarring in either eye, or insufficient hospital records or photographs to determine the extent of AMD. Clinical notes throughout the follow-up interval were reviewed. Two vitreoretinal specialists independently graded pre- and postvitrectomy fundus photographs of all eyes in a masked fashion.

MAIN OUTCOME MEASURES

The development or progression of geographic atrophy of the retinal pigment epithelium and the development of CNV.

RESULTS

Twenty-two patients were included. The average follow up interval was 5.5 years (range, 2-15). Choroidal neovascularization developed in 5 control eyes and in 2 vitrectomized eyes, and atrophy developed in 7 control and 4 vitrectomized eyes. The difference between vitrectomized eyes and fellow eyes for the combined end points of RPE geographic atrophy or CNV was significant (P = 0.02).

CONCLUSIONS

In this pilot study, we did not detect that vitrectomy increased the progression of AMD. In fact, it was associated with a reduced progression to geographic atrophy or CNV. Additional studies are needed to confirm or refute this association.

FINANCIAL DISCLOSURE(S)

The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Age-related accumulation of 3-nitrotyrosine and nitro-A2E in human Bruch's membrane

Age-related macular degeneration (AMD) is a disease leading to severe visual loss and legal blindness in the elderly population. The pathophysiology of AMD is complex and may include genetic predispositions, accumulation of lipofuscin and drusen, local inflammation and neovascularization. Recently four independent research groups have identified a commonly inherited variant (Y402H) of the complement factor H gene in the genome from different groups of AMD patients. The Y402H variant of CFH significantly increases the risk of AMD and links the genetics of the disease with inflammation. During inflammation there is activation of inducible nitric oxide synthase and release of nitric oxide, which in principal could lead to non-enzymatic nitration within extracellular deposits and/or intrinsic extracellular matrix protein components of human Bruch's membrane. We have identified two biomarkers for non-enzymatic nitration in aged human Bruch's membrane, indicative of inflammation, that include 3-nitrotyrosine identified in Bruch's membrane preparations and nitrated A2E from the lipid soluble extract of the Bruch's membrane preparation. Approximately 30-40 times more A2E is observed in samples of the organic soluble extract of lipofuscin compared to the extract of Bruch's membrane. It is of interest to note that although A2E is a major constituent of RPE lipofuscin, nitrated A2E could not be detected in RPE extracts. We show here that nitro-A2E is a specific biomarker of nitrosative stress in Bruch's membrane and its concentration correlates directly with tissue age.