28,000 Cases of age related macular degeneration causing visual loss in people aged 75 years and above in the United Kingdom may be attributable to smoking

Systemic inflammatory response index as a novel biomarker for age-related macular degeneration: a cross-sectional study from NHANES (2005-2008)

Background

Chronic low-grade systemic inflammation plays a significant role in age-related macular degeneration (AMD) pathogenesis. The systemic inflammatory response index (SIRI), a novel inflammatory marker, may predict various diseases. However, data on the relationship between SIRI and AMD are limited. This study examines the relationship between SIRI and AMD and assesses its potential as a predictive biomarker.

Methods

A cross-sectional analysis of the National Health and Nutrition Examination Survey (NHANES) data from 2005 to 2008 was conducted on participants aged ≥40 years with SIRI and AMD status data. Multivariable logistic regression models adjusted for confounders were used to assess the association. Sensitivity and subgroup analyses, along with restricted cubic spline (RCS) curve analysis, were performed.

Results

Among 5,365 participants, 425 (7.9%) had AMD. The median SIRI was higher in AMD patients (1.23 vs. 1.04, p < 0.001). Higher SIRI was independently associated with increased odds (adjusted OR: 1.18, 95% CI:1.07-1.29, p = 0.001). RCS analyses revealed a dose-response relationship (p = 0.002). Subgroup analyses showed a positive association in male participants, individuals with hypertension, individuals with obesity, and non-smokers. Higher SIRI levels were independently associated with increased AMD risk (adjusted OR: 1.27, 95% CI: 1.03-1.56, p = 0.023).

Conclusion

Elevated SIRI is independently associated with increased AMD risk in the U.S. population. SIRI may serve as a biomarker for identifying high-risk individuals, enabling early intervention. The cross-sectional design limits causal inference, and unmeasured confounders may affect the results. SIRI could potentially serve as a non-invasive biomarker for AMD risk, pending further validation through longitudinal studies.

Blue light-induced phototoxicity in retinal cells: implications in age-related macular degeneration

Sunlight exposure is recognized as a risk factor for the development of age-related macular degeneration (AMD), a common neurodegenerative retinal disease in the elderly. Specifically, the blue light wavelengths within sunlight can negatively impact the physiology of light-sensitive retinal cells, including retinal pigmented epithelium (RPE) and photoreceptors. This review explores blue light-induced retinal degeneration, emphasizing the structural and functional impairments in RPE. The initial section provides a brief overview of blue light's effects on photoreceptors, followed by a comprehensive analysis of its detrimental impact on RPE. In vitro studies reveal that blue light exposure induces morphological alterations and functional impairments in RPE, including reduced phagocytic activity, disrupted secretion of neurotrophic factors, and compromised barrier function. Mechanisms of retinal damage, including oxidative stress, inflammation, lipofuscin accumulation, mitochondrial dysfunction and ER stress in RPE, are also explored. The strengths and limitations of in vitro, animal and ex vivo models for studying blue light exposure are discussed, with recommendations for improving reproducibility in future studies.

Translational Research and Therapies for Neuroprotection and Regeneration of the Optic Nerve and Retina: A Narrative Review

Most retinal and optic nerve diseases pose significant threats to vision, primarily due to irreversible retinal neuronal cell death, a permanent change, which is a critical factor in their pathogenesis. Conditions such as glaucoma, retinitis pigmentosa, diabetic retinopathy, and age-related macular degeneration are the top four leading causes of blindness among the elderly in Japan. While standard treatments-including reduction in intraocular pressure, anti-vascular endothelial growth factor therapies, and retinal photocoagulation-can partially delay disease progression, their therapeutic effects remain limited. To address these shortcomings, a range of neuroprotective and regenerative therapies, aimed at preventing retinal neuronal cell loss, have been extensively studied and increasingly integrated into clinical practice over the last two decades. Several of these neuroprotective therapies have achieved on-label usage worldwide. This narrative review introduces several neuroprotective and regenerative therapies for retinal and optic nerve diseases that have been successfully translated into clinical practice, providing foundational knowledge and success stories that serve as valuable references for researchers in the field.

mTOR Signalling Pathway: A Potential Therapeutic Target for Ocular Neurodegenerative Diseases

Recent advances in the research of the mammalian target of the rapamycin (mTOR) signalling pathway demonstrated that mTOR is a robust therapeutic target for ocular degenerative diseases, including age-related macular degeneration (AMD), diabetic retinopathy (DR), and glaucoma. Although the exact mechanisms of individual ocular degenerative diseases are unclear, they share several common pathological processes, increased and prolonged oxidative stress in particular, which leads to functional and morphological impairment in photoreceptors, retinal ganglion cells (RGCs), or retinal pigment epithelium (RPE). mTOR not only modulates oxidative stress but is also affected by reactive oxygen species (ROS) activation. It is essential to understand the complicated relationship between the mTOR pathway and oxidative stress before its application in the treatment of retinal degeneration. Indeed, the substantial role of mTOR-mediated autophagy in the pathogenies of ocular degenerative diseases should be noted. In reviewing the latest studies, this article summarised the application of rapamycin, an mTOR signalling pathway inhibitor, in different retinal disease models, providing insight into the mechanism of rapamycin in the treatment of retinal neurodegeneration under oxidative stress. Besides basic research, this review also summarised and updated the results of the latest clinical trials of rapamycin in ocular neurodegenerative diseases. In combining the current basic and clinical research results, we provided a more complete picture of mTOR as a potential therapeutic target for ocular neurodegenerative diseases.

Biomarkers as Predictive Factors of Anti-VEGF Response

Age-related macular degeneration is the main cause of irreversible vision in developed countries, and intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections are the current gold standard treatment today. Although anti-VEGF treatment results in important improvements in the course of this disease, there is a considerable number of patients not responding to the standardized protocols. The knowledge of how a patient will respond or how frequently retreatment might be required would be vital in planning treatment schedules, saving both resource utilization and financial costs, but today, there is not an ideal biomarker to use as a predictive response to ranibizumab therapy. Whole blood and blood mononuclear cells are the samples most studied; however, few reports are available on other important biofluid samples for studying this disease, such as aqueous humor. Moreover, the great majority of studies carried out to date were focused on the search for SNPs in genes related to AMD risk factors, but miRNAs, proteomic and metabolomics studies have rarely been conducted in anti-VEGF-treated samples. Here, we propose that genomic, proteomic and/or metabolomic markers could be used not alone but in combination with other methods, such as specific clinic characteristics, to identify patients with a poor response to anti-VEGF treatment to establish patient-specific treatment plans.

Dark Adaptation and Its Role in Age-Related Macular Degeneration

Dark adaptation (DA) refers to the slow recovery of visual sensitivity in darkness following exposure to intense or prolonged illumination, which bleaches a significant amount of the rhodopsin. This natural process also offers an opportunity to understand cellular function in the outer retina and evaluate for presence of disease. How our eyes adapt to darkness can be a key indicator of retinal health, which can be altered in the presence of certain diseases, such as age-related macular degeneration (AMD). A specific focus on clinical aspects of DA measurement and its significance to furthering our understanding of AMD has revealed essential findings underlying the pathobiology of the disease. The process of dark adaptation involves phototransduction taking place mainly between the photoreceptor outer segments and the retinal pigment epithelial (RPE) layer. DA occurs over a large range of luminance and is modulated by both cone and rod photoreceptors. In the photopic ranges, rods are saturated and cone cells adapt to the high luminance levels. However, under scotopic ranges, cones are unable to respond to the dim luminance and rods modulate the responses to lower levels of light as they can respond to even a single photon. Since the cone visual cycle is also based on the Muller cells, measuring the impairment in rod-based dark adaptation is thought to be particularly relevant to diseases such as AMD, which involves both photoreceptors and RPE. Dark adaptation parameters are metrics derived from curve-fitting dark adaptation sensitivities over time and can represent specific cellular function. Parameters such as the cone-rod break (CRB) and rod intercept time (RIT) are particularly sensitive to changes in the outer retina. There is some structural and functional continuum between normal aging and the AMD pathology. Many studies have shown an increase of the rod intercept time (RIT), i.e., delays in rod-mediated DA in AMD patients with increasing disease severity determined by increased drusen grade, pigment changes and the presence of subretinal drusenoid deposits (SDD) and association with certain morphological features in the peripheral retina. Specifications of spatial testing location, repeatability of the testing, ease and availability of the testing device in clinical settings, and test duration in elderly population are also important. We provide a detailed overview in light of all these factors.

Association Between Tobacco Consumption and Self-Reported Visual Impairment in Adults of High-Altitude Andean Communities of Peru

To determine the association between tobacco consumption and self-reported visual impairment. We performed a cross-sectional study based on an original cohort study. A non-probabilistic sampling was performed to invite 413 patients of 60 years or more from 11 high-altitude Andean communities (altitude higher than 1500 m above sea level) of Peru between 2013 and 2017. Demographic data and information on tobacco consumption were collected. Associations were determined using a Poisson regression model with 95% confidence intervals (CI). Of the 413 participants, 141 (34.14%) were men and 49 (11.86%) were tobacco users. In the adjusted model, tobacco users presented a high probability of visual impairment with a prevalence ratio of 1.32 (95% CI: 1.18–1.97). We also found that having two or more comorbidities 2.19 (95% CI: 1.53–3.15), receiving health assistance in a pharmacy 3.75 (95% CI: 1.97–7.16), and coffee consumption 1.67 (95% CI: 1.26–2.21) were factors significantly associated with self-reported visual impairment. We determined that in Peruvian high-altitude Andean communities, visual impairment was more frequent in individuals reporting tobacco consumption, taking alternative medicine, going directly to a drug store without primary care physician consultation, having more than one comorbidity, and coffee consumption.

ULTRAWIDEFIELD PSEUDOCOLOR RETINAL IMAGING VERSUS REAL-COLOR FUNDUS PHOTOGRAPHY FOR DETECTION OF INTRARETINAL PIGMENT MIGRATION IN AGE-RELATED MACULAR DEGENERATION

PURPOSE

To compare pseudocolor Optos ultrawidefield (UWF) retinal images with conventional real-color fundus photography (CFP) for detecting macular hyperpigmentary changes in intermediate age-related macular degeneration.

METHODS

This retrospective study included 50 patients diagnosed with intermediate age-related macular degeneration. All patients underwent Optos imaging and CFP. The overall accuracy to visualize hyperpigmentation and its morphologic features was graded by two independent readers using a standardized grid. Structural and en face optical coherence tomography images were correlated with UWF and CFP images to determine spatial correspondence of pigment clumping on fundus images and hyperreflective foci on optical coherence tomography.

RESULTS

One hundred eyes of 50 patients had hyperpigmentary changes on funduscopic examination and were included. The intragraders and intergraders agreements were high for all measurements (P < 0.001). At least one hyperpigmentary changes within the standardized grid was detected in 93% using CFP and 100% using UWF camera (P = 0.02). The total area of hyperpigmentation measured on UWF images was significantly higher than on CFP images (P < 0.001). There was a significant correlation between the presence of hyperpigmentary changes on both CFP and UWF images and hyperreflective foci on structural optical coherence tomography (P < 0.001).

CONCLUSION

Ultrawidefield fundus images allow high detection and accurate quantification of macular hyperpigmentary changes in intermediate age-related macular degeneration compared with conventional CFP.

Smoking, urinary cotinine levels and incidence of visual impairment

The longitudinal relationship between smoking status and risk of developing visual impairment (VI) remains unclear. We examined the relationship of smoking status and urinary cotinine level, an objective measure of smoking, with incidence of VI. This cohort study included 279,069 individuals free of VI who were followed for up to 8.8 years (median 4.8 years). VI was defined as when bilateral visual acuity was worse than 0.5 (cutoffs of 0.3 Logarithm of the Minimum Angle of Resolution). During 1,324,429.8 person-years of follow-up, 7852 participants developed new-onset bilateral VI. Self-reported current smoking status was associated with increased risk of developing VI in both men and women, with a stronger association in women (P for interaction = 0.01). Multivariable adjusted hazard ratios (95% confidence intervals) for incident VI comparing current smokers to never-smokers were 1.14 (1.04–1.25) in men and 1.52 (1.28–1.80) in women. Urinary cotinine levels of ≥ 100 ng/ml were significantly associated with increased risk of incident VI, and these associations remained when introducing changes in urinary cotinine and other confounders during follow-up as time-varying covariates. Cigarette smoking assessed based on self-report and urinary cotinine level was associated with increased incidence of VI. Our findings identify smoking as an independent risk factor for VI.

Treatment regimens for administration of anti-vascular endothelial growth factor agents for neovascular age-related macular degeneration

BACKGROUND

Age-related macular degeneration (AMD) is one of the leading causes of permanent blindness worldwide. The current mainstay of treatment for neovascular AMD (nAMD) is intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) agents: aflibercept, ranibizumab, and off-label bevacizumab. Injections can be given monthly, every two or three months ('extended-fixed'), or as needed (pro re nata (PRN)). A variant of PRN is 'treat-and-extend' whereby injections are resumed if recurrence is detected and then delivered with increasing intervals. Currently, injection frequency varies among practitioners, which underscores the need to characterize an optimized approach to nAMD management.

OBJECTIVES

To investigate the effects of monthly versus non-monthly intravitreous injection of an anti-VEGF agent in people with newly diagnosed nAMD.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, LILACS, and three trials registers from 2004 to October 2019; checked references; handsearched conference abstracts; and contacted pharmaceutical companies to identify additional studies.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that compared different treatment regimens for anti-VEGF agents in people with newly diagnosed nAMD. We considered standard doses only (ranibizumab 0.5 mg, bevacizumab 1.25 mg, aflibercept 2.0 mg, or a combination of these).

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods for trial selection, data extraction, and analysis.

MAIN RESULTS

We included 15 RCTs. The total number of participants was 7732, ranging from 37 to 2457 in each trial. The trials were conducted worldwide. Of these, six trials exclusively took place in the US, and three included centers from more than one country. Eight trials were at high risk of bias for at least one domain and all trials had at least one domain at unclear risk of bias. Seven trials (3525 participants) compared a PRN regimen with a monthly injection regimen, of which five trials delivered four to eight injections using standard PRN and three delivered nine or 10 injections using a treat-and-extend regimen in the first year. The overall mean change in best-corrected visual acuity (BCVA) at one year was +8.8 letters in the monthly injection group. Compared to the monthly injection, there was moderate-certainty evidence that the mean difference (MD) in BCVA change at one year for the standard PRN subgroup was -1.7 letters (95% confidence interval (CI) -2.8 to -0.6; 4 trials, 2299 participants), favoring monthly injections. There was low-certainty evidence of a similar BCVA change with the treat-and-extend subgroup (0.5 letters, 95% CI -3.1 to 4.2; 3 trials, 1226 participants). Compared to monthly injection, there was low-certainty evidence that fewer participants gained 15 or more lines of vision with standard PRN treatment at one year (risk ratio (RR) 0.87, 95% CI 0.76 to 0.99; 4 trials, 2299 participants) and low-certainty evidence of a similar gain with treat-and-extend versus monthly regimens (RR 1.11, 95% CI 0.91 to 1.36; 3 trials, 1169 participants). The mean change in central retinal thickness was a decrease of -166 μm in the monthly injection group; the MD compared with standard PRN was 21 μm (95% CI 6 to 32; 4 trials, 2215 participants; moderate-certainty evidence) and with treat-and extend was 22 μm (95% CI 37 to -81 μm; 2 trials, 635 participants; low-certainty evidence), in favor of monthly injection. Only one trial (498 participants) measured quality of life and reported no evidence of a difference between regimens, but data could not be extracted (low-certainty evidence). Both PRN regimens (standard and 'treat-and-extend') used fewer injections than monthly regimens (standard PRN: MD -4.6 injections, 95% CI -5.4 to -3.8; 4 trials, 2336 participants; treat-and-extend: -2.4 injections, 95% CI -2.7 to -2.1 injections; moderate-certainty evidence for both comparisons). Two trials provided cost data (1105 participants, trials conducted in the US and the UK). They found that cost differences between regimens were reduced if bevacizumab rather than aflibercept or ranibizumab were used, since bevacizumab was less costly (low-certainty evidence). PRN regimens were associated with a reduced risk of endophthalmitis compared with monthly injections (Peto odds ratio (OR) 0.13, 95% CI 0.04 to 0.46; 6 RCTs, 3175 participants; moderate-certainty evidence). Using data from all trials included in this review, we estimated the risk of endophthalmitis with monthly injections to be 8 in every 1000 people per year. The corresponding risk for people receiving PRN regimens was 1 in every 1000 people per year (95% CI 0 to 4). Three trials (1439 participants) compared an extended-fixed regimen (number of injections reported in only one large trial: 7.5 in one year) with monthly injections. There was moderate-certainty evidence that BCVA at one year was similar for extended-fixed and monthly injections (MD in BCVA change compared to extended-fixed group: -1.3 letters, 95% CI -3.9 to 1.3; RR of gaining 15 letters or more: 0.94, 95% CI 0.80 to 1.10). The change in central retinal thickness was a decrease of 137 μm in the monthly group; the MD with the extended-fixed group was 8 μm (95% CI -11 to 27; low-certainty evidence). The frequency of endophthalmitis was lower in the extended-fixed regimen compared to the monthly group, but this estimate was imprecise (RR 0.19, 95% CI 0.03 to 1.11; low-certainty evidence). If we assumed a risk of 8 cases of endophthalmitis in 1000 people receiving monthly injections over one year, then the corresponding risk with extended-fixed regimen was 2 in 1000 people (95% CI 0 to 9). Other evidence comparing different extended-fixed or PRN regimens yielded inconclusive results.

AUTHORS' CONCLUSIONS

We found that, at one year, monthly regimens are probably more effective than PRN regimens using seven or eight injections in the first year, but the difference is small and clinically insignificant. Endophthalmitis is probably more common with monthly injections and differences in costs between regimens are higher if aflibercept or ranibizumab are used compared to bevacizumab. This evidence only applies to settings in which regimens are implemented as described in the trials, whereas undertreatment is likely to be common in real-world settings. There are no data from RCTs on long-term effects of different treatment regimens.

Integrated bioinformatics analysis of aberrantly-methylated differentially-expressed genes and pathways in age-related macular degeneration

Background

Age-related macular degeneration (AMD) represents the leading cause of visual impairment in the aging population. The goal of this study was to identify aberrantly-methylated, differentially-expressed genes (MDEGs) in AMD and explore the involved pathways via integrated bioinformatics analysis.

Methods

Data from expression profile GSE29801 and methylation profile GSE102952 were obtained from the Gene Expression Omnibus database. We analyzed differentially-methylated genes and differentially-expressed genes using R software. Functional enrichment and protein–protein interaction (PPI) network analysis were performed using the R package and Search Tool for the Retrieval of Interacting Genes online database. Hub genes were identified using Cytoscape.

Results

In total, 827 and 592 genes showed high and low expression, respectively, in GSE29801; 4117 hyper-methylated genes and 511 hypo-methylated genes were detected in GSE102952. Based on overlap, we categorized 153 genes as hyper-methylated, low-expression genes (Hyper-LGs) and 24 genes as hypo-methylated, high-expression genes (Hypo-HGs). Four Hyper-LGs (CKB, PPP3CA, TGFB2, SOCS2) overlapped with AMD risk genes in the Public Health Genomics and Precision Health Knowledge Base. KEGG pathway enrichment analysis indicated that Hypo-HGs were enriched in the calcium signaling pathway, whereas Hyper-LGs were enriched in sphingolipid metabolism. In GO analysis, Hypo-HGs were enriched in fibroblast migration, membrane raft, and coenzyme binding, among others. Hyper-LGs were enriched in mRNA transport, nuclear speck, and DNA binding, among others. In PPI network analysis, 23 nodes and two edges were established from Hypo-HGs, and 151 nodes and 73 edges were established from Hyper-LGs. Hub genes (DHX9, MAPT, PAX6) showed the greatest overlap.

Conclusion

This study revealed potentially aberrantly MDEGs and pathways in AMD, which might improve the understanding of this disease.

REAL-COLOR VERSUS PSEUDO-COLOR IMAGING OF FIBROTIC SCARS IN EXUDATIVE AGE-RELATED MACULAR DEGENERATION

PURPOSE

To compare the morphological characteristics of subretinal fibrosis in late age-related macular degeneration using multicolor (MC) imaging, color fundus photography (CFP), and ultra-widefield CFP (UWFCFP).

METHODS

Thirty-two eyes of 31 patients diagnosed with subretinal fibrosis complicating exudative age-related macular degeneration were included. Included eyes were imaged by MC, CFP, and UWFCFP. The overall ability to visualize fibrosis, its margins, and dissimilarity with surrounding atrophy was graded using a score (0: not visible, 1: barely visible, 2: mostly visible, and 3: fully visible) by two readers. Area of fibrosis was calculated. Scaling, lesion colocalization on all three imaging techniques, and area measurements were performed using ImageJ.

RESULTS

Ninety-six images of 32 eyes were graded. The average area of fibrosis was 14.59 ± 8.94 mm for MC, 13.84 ± 8.56 mm for CFP, and 13.76 ± 8.79 mm for UWFCFP. Fibrosis was fully visible in 87.5% of cases using MC and 50% using CFP and UWFCFP. Fibrosis' margins were sharply defined in 40.6% of eyes with MC, 15.6% and 9.4% with CFP and UWFCFP, respectively. Multicolor imaging provided superior distinction between fibrosis and atrophy (100% for MC vs. 13.4% for CFP and 33.3% for UWFCFP). The inter- and intra-reader agreement was high for all measurements (P < 0.0001).

CONCLUSION

Multicolor technology allows for improved visualization and analysis of subretinal fibrosis when compared with CFP and UWFCFP, especially when surrounding atrophy is present.

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.

Optometry Australia's chairside reference for the diagnosis and management of age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of irreversible vision loss in people over the age of 50 years in Australia. Optometry Australia has developed this AMD chairside reference in consultation with a member-based working group comprised of experienced practitioners. It provides an evidence-based approach to current best practice in the diagnosis and management of AMD. Optometrists should be competent in assessing patients with or at risk of developing AMD, so that they are able to provide evidence-based management including appropriate communication, diagnosis and referral when indicated. This AMD chairside reference covers risk factors for the development of AMD or progression to late-stage AMD; the current clinical classification of AMD; common signs and symptoms; optometric assessment including ocular imaging and biomarkers; differential diagnoses; and management of early, intermediate and late AMD. Optometry Australia's chairside reference is intended as a general guide for optometrists, and is not a formal management protocol.

IDENTIFYING FEATURES OF EARLY AND LATE AGE-RELATED MACULAR DEGENERATION: A Comparison of Multicolor Versus Traditional Color Fundus Photography

PURPOSE

To compare multicolor (MC) and traditional color fundus photography (CFP) in their ability to detect features of early and late age-related macular degeneration (AMD).

METHODS

Study design: Observational case series.

PARTICIPANTS

fundus images captured using standard CFP and MC imaging from 33 patients attending hospital clinics and 26 participants from the pilot phase of the Northern Ireland Cohort for the Longitudinal Study of Ageing (NICOLA). Systematic grading of early and late AMD features; (hard drusen, soft drusen, reticular pseudodrusen, pigment clumping, non-geographic atrophy hypopigmentation, atrophy, hemorrhage, and fibrosis) on CFP and MC.

RESULTS

There were 105 eyes with gradable images for comparison. Using CFP as the gold standard, sensitivity values for MC ranged from 100% for atrophy, non-geographic atrophy hypopigmentation, and fibrosis to 69.7% for pigment clumping. Specificity values were high: >80% for all features. On using MC as the comparator, CFP had lower sensitivity for the detection of early AMD features (27.8% for reticular drusen to 77.8% for non-geographic atrophy hypopigmention). Analysis of OCT in discrepant cases showed better agreement with MC for all AMD lesions, except hemorrhage and non-geographic atrophy hypopigmentation. For pigment clumping, CFP and MC were in equal agreement with OCT.

CONCLUSION

Multicolor retinal imaging allowed for improved detection and definition of AMD features.

Complement System and Age-Related Macular Degeneration: Implications of Gene-Environment Interaction for Preventive and Personalized Medicine

Age-related macular degeneration (AMD) is the most common cause of visual loss in developed countries, with a significant economic and social burden on public health. Although genome-wide and gene-candidate studies have been enabled to identify genetic variants in the complement system associated with AMD pathogenesis, the effect of gene-environment interaction is still under debate. In this review we provide an overview of the role of complement system and its genetic variants in AMD, summarizing the consequences of the interaction between genetic and environmental risk factors on AMD onset, progression, and therapeutic response. Finally, we discuss the perspectives of current evidence in the field of genomics driven personalized medicine and public health.

Trends in Blind and Low Vision Registrations in Taipei City

Purpose

To determine the overall reported incidence and causes of registrable blindness and low vision in Taipei, Taiwan, that have occurred in the previous 10 years.

Methods

Study data were obtained from disability identification registration forms completed between January 1995 and December 2004. Definitions of low vision and blindness were defined by WHO criteria: low vision included visual acuity worse than 6/18 (20/60) to a lower limit of 3/60 (20/400). Blindness was defined as visual acuity worse than 3/60 (20/400) in the better eye with best possible correction.

Results

There were 3151 registrations for visual impairment during the study period. A total of 239 registrations were excluded due to insufficient data. Of the remaining 2912 (1518 males and 1394 females), 640 males and 647 females were legally blind (44.20%). A total of 878 males and 747 females were partially sighted. The six leading causes of low vision and blindness, in decreasing frequency, were glaucoma, optic neuropathy, diabetic retinopathy, retinitis pigmentosa, age-related macular degeneration, and myopic macular degeneration.

Conclusions

The proportions of new registrations owing to glaucoma, diabetic retinopathy, age-related macular degeneration, and myopic macular degeneration have changed significantly since 2000; the proportion due to diabetic retinopathy has increased.

Prevalence and the risk factors for visual impairment in age-related macular degeneration

PurposeTo characterize the type, and the causes of visual impairment (VI) in various stages of early and late age-related macular degeneration (AMD) and the factors associated with visual impairment in subjects with AMDMethods6617 subjects ≥60 years were enumerated; 5495 (83.04%) participated in eye examination. Of which, 4791 subjects had gradable fundus images. AMD was graded per International ARM Epidemiological Study Group. Subjects underwent detailed ophthalmic exam. VI was defined per the WHO classification. Mild VI was defined as VA less than 6/12 to 6/18, moderate VI-VA less than 6/18 but up to 6/60, severe VI-VA less than 6/60 but up to 3/60 and legal blindness-VA worse than 3/60. Factors associated with VI in AMD was analyzed with univariate and logistic regression analysis.ResultsNine hundred and eighty-eight subjects were identified as having AMD (893 with early AMD and 95 with late AMD); 85% of the subjects (95% CI: 82.7-87.1) had no VI, 13.1% had mild VI (95% CI: 11.1-15.3), 0.8% had severe VI (95% CI: 0.4-1.6), 1.1% had legal blindness (95% CI: 0.6-1.9). Prevalence of any VI was 13.7% in early AMD and 27.4% in late AMD, P=0.0004; age group 65-70 years (OR=1.89, 95% CI: 1.16-3.08, P=0.011), and those ≥75 years (OR=3.67, 95% CI: 1.95-6.91, P=0.0001) had greater odds of VI compared with age group 60-64 years. Male gender was a protective factor for VI (OR=0.57, CI: 0.36-0.90, P=0.016). Cataract (31.8%) and refractive error (28.4%) accounted for a majority of the VI.ConclusionsCataract and refractive error account for a significant proportion of VI in the south Indian population with AMD. Early AMD is the third leading cause of VI. Greater age and female gender are associated with VI in subjects with AMD.

Risk factors and biomarkers of age-related macular degeneration

A biomarker can be a substance or structure measured in body parts, fluids or products that can affect or predict disease incidence. As age-related macular degeneration (AMD) is the leading cause of blindness in the developed world, much research and effort has been invested in the identification of different biomarkers to predict disease incidence, identify at risk individuals, elucidate causative pathophysiological etiologies, guide screening, monitoring and treatment parameters, and predict disease outcomes. To date, a host of genetic, environmental, proteomic, and cellular targets have been identified as both risk factors and potential biomarkers for AMD. Despite this, their use has been confined to research settings and has not yet crossed into the clinical arena. A greater understanding of these factors and their use as potential biomarkers for AMD can guide future research and clinical practice. This article will discuss known risk factors and novel, potential biomarkers of AMD in addition to their application in both academic and clinical settings.

Genetic Association Analysis of Drusen Progression

PURPOSE

Age-related macular degeneration is a common form of vision loss affecting older adults. The etiology of AMD is multifactorial and is influenced by environmental and genetic risk factors. In this study, we examine how 19 common risk variants contribute to drusen progression, a hallmark of AMD pathogenesis.

METHODS

Exome chip data was made available through the International AMD Genomics Consortium (IAMDGC). Drusen quantification was carried out with color fundus photographs using an automated drusen detection and quantification algorithm. A genetic risk score (GRS) was calculated per subject by summing risk allele counts at 19 common genetic risk variants weighted by their respective effect sizes. Pathway analysis of drusen progression was carried out with the software package Pathway Analysis by Randomization Incorporating Structure.

RESULTS

We observed significant correlation with drusen baseline area and the GRS in the age-related eye disease study (AREDS) dataset (ρ = 0.175, P = 0.006). Measures of association were not statistically significant between drusen progression and the GRS (P = 0.54). Pathway analysis revealed the cell adhesion molecules pathway as the most highly significant pathway associated with drusen progression (corrected P = 0.02).

CONCLUSIONS

In this study, we explored the potential influence of known common AMD genetic risk factors on drusen progression. Our results from the GRS analysis showed association of increasing genetic burden (from 19 AMD associated loci) to baseline drusen load but not drusen progression in the AREDS dataset while pathway analysis suggests additional genetic contributors to AMD risk.

Danish Rural Eye Study: Epidemiology of Adult Visual Impairment

PURPOSE

To examine the frequency and causes of visual impairment (VI) in a select population of Danish adults.

METHODS

A total of 3843 adults aged 20-94 years from the Danish General Suburban Population Study (GESUS) were included in the population-based, cross-sectional ophthalmological study, Danish Rural Eye Study (DRES). All DRES participants received a comprehensive general health examination preceding their eye examination, including measurement of best-corrected visual acuity (BCVA) for each eye, bilateral 45° retinal fundus photographs and further ophthalmological examination where indicated.

RESULTS

Overall, 3826 of 3843 participants (99.6%) had bilateral visual acuity measurements. The overall frequency of VI (BCVA <20/40 in the better-seeing eye) was 0.4% (95% confidence interval, CI, 0.2-0.7%; n = 15) among all DRES participants, 0.6% (95% CI 0.3-1.0%; n = 15) among participants >50 years and 3.7% (95% CI 2.1-6.5%; n = 11) in participants >80 years. The primary causes of VI in the better-seeing eye were age-related macular degeneration (AMD) in 46.7% (7/15) and cataract in 26.7% (4/15). A total of 43.3% (n = 115) of participants >80 years were pseudophakic in one or both eyes. The frequency of diabetes (HbA1c ≥ 48 mmol/mol or self-reported diagnosis) was 5.9% (n = 227), including 1.3% (n = 51) newly diagnosed in the GESUS. Of participants determined to have VI due to exudative AMD, 50% had received anti-vascular endothelial growth factor (VEGF) treatment.

CONCLUSION

We report a relatively low frequency of VI among Danish adults over 59 years of age compared with that observed 10-15 years ago, which is both consistent with other recent Scandinavian studies and reflective of our relatively healthy and mobile population sample.

The self-reported clinical practice behaviors of Australian optometrists as related to smoking, diet and nutritional supplementation

OBJECTIVE

The primary aim of this study was to examine the self-reported, routine clinical practice behaviors of Australian optometrists with respect to advice regarding smoking, diet and nutritional supplementation. The study also sought to assess the potential influence of practitioner age, gender, practice location (major city versus regional), therapeutic-endorsement status and personal nutritional supplementation habits upon management practices in these areas.

METHODS

A survey was electronically distributed to Australian optometrists (n = 4,242). Respondents anonymously provided information about their personal demographics and lifestyle behaviors (i.e., age, gender, practice location, therapeutic-endorsement status, smoking status, nutritional supplement intake) and routine patient management practices with respect to advice across three domains: smoking, diet and nutritional supplementation. Multivariate logistic regression analyses were performed to assess for potential effects of the listed factors on practitioner behavior.

RESULTS

A total of 283 completed surveys were received (completed survey response rate: 6.7%). Fewer than half of respondents indicated routinely asking their patients about smoking status. Younger practitioners were significantly (p < 0.05) less likely to enquire about patients' smoking behaviors, but this did not extend to counseling for smoking cessation. Almost two-thirds of respondents indicated routinely counseling patients about diet. About half of practitioners specified routinely asking their patients about nutritional supplement intake; this form of questioning was significantly more likely if the respondent was female (p < 0.05). Practitioners who recommended nutritional supplements most commonly did so for age-related macular degeneration (91.2%) and dry eye disease (63.9%). The primary source of evidence used to guide practitioners' nutrition-related patient management was reported to be peer-reviewed publications.

CONCLUSIONS

These findings demonstrate that there are no clear predictors of practitioner behavior across the three domains. Overall, this study suggests that there is scope for Australian optometrists to improve their routine engagement by questioning patients, as well as providing evidence-based clinical advice, about smoking status, diet and nutritional supplement behaviors, being key modifiable lifestyle risk factors with long-term implications for eye health.

Genetic predictive biomarkers of anti-VEGF treatment response in patients with neovascular age-related macular degeneration

Anti-vascular endothelial growth factor (anti-VEGF) therapies for neovascular age-related macular degeneration (nAMD) have proven efficacy at a study-population level, although individual patient responses vary, with most of the patients responding well to anti-VEGF therapies, while a few respond poorly. The pathogenesis of AMD is known to have a genetic component, but it is unclear if any particular genotype can predict response to anti-VEGF therapy. With the advent of less expensive genotyping technology, there have been numerous studies within this area. Here we analyze potential biomarker candidates identified that could be used in a clinical setting to predict response to anti-VEGF treatment of nAMD. We analyze single nucleotide polymorphisms (SNPs) identified from 39 publications. The SNPs that appeared to be of most importance fell into two main groups: those previously associated with AMD pathogenesis and those within the signaling pathway targeted by anti-VEGF therapies. A number of small studies found evidence supporting an association between anti-VEGF treatment response and two SNPs, CFH rs1061170 and VEGFA rs699947, but results from randomized controlled trials found no such association. It is possible that, in the future, the cumulative effect of several high-risk SNPs may prove useful in a clinical setting and that other genetic biomarkers may emerge.

Nutrition and age-related macular degeneration: research evidence in practice

Age-related macular degeneration (AMD) is the leading cause of irreversible visual impairment in developed countries. In the absence of effective treatments to slow AMD progression, it is predicted that the prevalence of AMD will double over the next 20 years. One area of significant interest is the potential role that nutrition may play in preventing and/or delaying the progression of AMD. Specifically, is there any benefit in oral antioxidant and/or mineral supplementation? This review critically evaluates the currently available evidence relating to nutrition and AMD, with particular reference to the key findings of two large National Eye Institute-sponsored clinical studies, namely, the Age-Related Eye Disease Study (AREDS) and AREDS2. Topical controversies relating to nutrition and AMD are considered and analyzed in the context of the published literature to guide practitioners through assessing the merit, or otherwise, of common claims. This article provides a foundation for clinicians to provide informed advice to AMD patients based on available research evidence.

'I'd like to know what causes it, you know, anything I've done?' Are we meeting the information and support needs of patients with macular degeneration? A qualitative study

OBJECTIVE

To examine patients' experiences of information and support provision for age-related macular degeneration (AMD) in the UK.

STUDY DESIGN

Exploratory qualitative study investigating patient experiences of healthcare consultations and living with AMD over 18 months.

SETTING

Specialist eye clinics at a Birmingham hospital.

PARTICIPANTS

13 patients diagnosed with AMD.

MAIN OUTCOME MEASURES

Analysis of patients' narratives to identify key themes and issues relating to information and support needs.

RESULTS

Information was accessed from a variety of sources. There was evidence of clear information deficits prior to diagnosis, following diagnosis and ongoing across the course of the condition. Patients were often ill informed and therefore unable to self-advocate and recognise when support was needed, what support was available and how to access support.

CONCLUSIONS

AMD patients have a variety of information needs that are variable across the course of the condition. Further research is needed to determine whether these experiences are typical and identify ways of translating the guidelines into practice. Methods of providing information need to be investigated and improved for this patient group.

Effects of smoking on visual acuity of central serous chorioretinopathy patients

BACKGROUND

The aim of this study was to evaluate the differences, in terms of visual outcome and treatment needs, between smokers and non-smokers central serous chorioretinopathy (CSCR) patients.

METHODS

The files of 252 patients diagnosed with CSCR who had presented to the Retina Unit of the Ophthalmology Clinic at Dicle University Medical School in Turkey were retrospectively evaluated. Eighty-four smokers, with a known history of smoking of at least one pack-year, and 133 non-smokers were included, whereas 35 patients with additional pathologies were excluded from the study.

RESULTS

Of the patients, 192 (88.5%) were male and 25 (11.5%) were female. The mean patient age was 38.8 ± 8.1 years (range: 20-68 years). Visual acuity (VA) of the smoker and non-smoker groups was measured as 0.45 ± 0.35 and 0.24 ± 0.28 logarithm of the minimum angle of resolution (logMar), respectively, at the first visit; 0.19 ± 0.29 and 0.06 ± 0.14 logMar at the sixth month; and 0.07 ± 0.14 and 0.02 ± 0.05 logMar at the ninth month. VA measurements at presentation and during all examinations (1th, 6th and 9th month) were significantly different for the two groups. VA was lower in the smoker group. In 27 patients (12.4%), an additional treatment modality was needed. Of the 27 patients, only 8 (6%) were non-smokers, whereas 19 (22.6%) were smokers. There was no difference between groups in the recurrence rate during follow-up (p = 0.907); 14 (16.7%) smokers and 8 (19.0%) non-smokers experienced a recurrence.

CONCLUSION

This study has shown that patients selected and who are current smokers have poorer vision and need longer treatment.

Advice about diet and smoking for people with or at risk of age-related macular degeneration: a cross-sectional survey of eye care professionals in the UK

Background

In the absence of a cure, there has been considerable interest in attempts to prevent or reduce the progression of age-related macular degeneration (AMD) by targeting particular modifiable risk factors. The aim of this study was to conduct a cross-sectional survey of the current practice of UK eye care professionals in relation to advice given on diet and other lifestyle modifications for patients with or at risk of AMD.

Methods

Optometrists and ophthalmologists on the membership databases of professional organisations for the two professions were invited to participate in an online survey. The survey was open for 12 weeks between July and September 2012.

Results

A total of 1,468 responses were received (96.3% from optometrists and 3.7% from ophthalmologists). The response rate of those receiving the invitation was 16.2% (1,414/8735) for optometrists and 6% (54/1460) for ophthalmologists. A majority of respondents reported that they frequently provide dietary advice to patients with established AMD (67.9%) and those at risk of AMD (53.6%). Typical advice consisted of a recommendation to eat plenty of leafy green vegetables and eat more oily fish. The decision to recommend nutritional supplements was based on the risk of progression to advanced AMD, with approximately 93% of respondents recommending supplementation in a patient with advanced AMD in one eye. However for the majority, the type of supplement recommended did not comply with current best research evidence, based on the findings of the Age-related Eye Disease Study (AREDS). Only one in three optometrists regularly assessed smoking status and advised on smoking cessation.

Conclusions

Within a large sample of eye care professionals, consisting predominantly of optometrists, who responded to a cross-sectional survey, there was active engagement in providing nutritional advice to patients with or at risk of AMD. However, the results demonstrate a need to raise awareness of the evidence underpinning the use of nutritional supplements together with an increased involvement in targeted smoking cessation.

Smoking cessation: promoting the health of older people who smoke

Community nurses are well placed to address smoking behaviour with older people. Smoking cessation can significantly improve the health and wellbeing of older people, and to withhold support for smoking cessation is a form of age discrimination. This paper provides advice to community nurses about how to approach discussions about smoking behaviour with older clients as part of their health education practice. It addresses some of the ethical concerns that have been raised by community nurses, explains how smoking in older people may be reduced using a harm reduction apporoach and through working with the concept of the smoke-free home.

Influence of TIMP3/SYN3 polymorphisms on the phenotypic presentation of age-related macular degeneration

Age-related macular degeneration (AMD) is a leading cause of irreversible central visual loss in the elderly. A recent genome-wide association studies (GWAS) reported that rs9621532 near the tissue inhibitor of metalloproteinase 3 (TIMP3)/synapsin III (SYN3) region of 22q12.3 is associated with AMD. In this study, we characterize its phenotypic influence on AMD using three independent study cohorts: case-control studies from the National Eye Institute Clinical Center (NEI, n=397) and the Age-Related Eye Disease Study (n=523) as well as a nested case-control study from Blue Mountains Eye Study (BMES, n=852). Comparisons between cases and controls show no association between rs9621532 and AMD in the three sample sets. However, stratifying NEI cases uncovers a moderate protective role of rs9621532 in neovascular AMD (nAMD) and the association adhered to a dominant model (odds ratios=0.32; 95% CI: 0.11-0.89; P=0.02). The BMES data followed the same pattern of association with nAMD as that seen in the NEI sample but did not reach statistical significance. Polychotomous logistic regression showed a trend that rs9621532 correlates with less severe disease, for example, with the majority of carriers having intermediate AMD rather than nAMD/geographic atrophy AMD. Functionally, rs9621532 influences TIMP3 mRNA expression in cultured primary human fetal retinal pigment epithelium (hfRPE) cells. In hfRPE donors carrying the protective rs9625132 allele, we measured a reduction in TIMP3 mRNA by quantitative RT-PCR. Our data suggest that rs9621532 carriers have a lower risk of developing nAMD, potentially because of decreased transcription of TIMP3.

Positive impact of Australian 'blindness' tobacco warning labels: findings from the ITC four country survey

BACKGROUND

Smokers with greater knowledge of the health effects of smoking are more likely to quit and remain abstinent. Australia has communicated the causal association of smoking and blindness since the late 1990s. In March 2007, Australia became the first country to include a pictorial warning label on cigarette packages with the message that smoking causes blindness. The current study tested the hypothesis that the introduction of this warning label increased smokers' knowledge of this important health effect.

METHODS

Six waves of the International Tobacco Control Four Country Survey were conducted, as a telephone survey of 17,472 adult smokers in Australia, Canada, United Kingdom and the United States, with three waves before and three waves after the blindness health warning was introduced in Australia. The survey measured adult smokers' knowledge that smoking causes blindness.

RESULTS

Australian smokers were significantly more likely to report that smoking causes blindness, compared to Canadian, UK and US smokers, where there were neither health campaigns nor health warnings labels about blindness. After the introduction of the blindness warning, Australian smokers were more likely than before the blindness warning to report that they know that smoking causes blindness (62 versus 49 per cent; OR = 1.68, 95% CI: 1.03, 2.76, p = 0.04). In Australia, smokers aged over 55 years were less likely than those aged 18 to 24 to report that smoking causes blindness (OR = 0.43; 95% CI: 0.29, 0.62, p < 0.001).

CONCLUSION

While more smokers report that smoking causes blindness in Australia compared to other countries, which have not had national social marketing campaigns, further gains in knowledge were found after pictorial warning labels were introduced in Australia. Findings suggest there is still a need to educate the public about the causal association of smoking and blindness. More education may be needed to redress the knowledge gap in older Australian smokers as the incidence of age-related macular degeneration increases with age.

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.

Nicotine: specific role in angiogenesis, proliferation and apoptosis

Nowadays, tobacco smoking is the cause of ~5-6 million deaths per year, counting 31% and 6% of all cancer deaths (affecting 18 different organs) in middle-aged men and women, respectively. Nicotine is the addictive component of tobacco acting on neuronal nicotinic receptors (nAChR). Functional nAChR, are also present on endothelial, haematological and epithelial cells. Although nicotine itself is regularly not referred to as a carcinogen, there is an ongoing debate whether nicotine functions as a 'tumour promoter'. Nicotine, with its specific binding to nAChR, deregulates essential biological processes like regulation of cell proliferation, apoptosis, migration, invasion, angiogenesis, inflammation and cell-mediated immunity in a wide variety of cells including foetal (regulation of development), embryonic and adult stem cells, adult tissues as well as cancer cells. Nicotine seems involved in fundamental aspects of the biology of malignant diseases, as well as of neurodegeneration. Investigating the biological effects of nicotine may provide new tools for therapeutic interventions and for the understanding of neurodegenerative diseases and tumour biology.

Smoking as a risk factor for choroidal neovascularization secondary to presumed ocular histoplasmosis syndrome

PURPOSE

To investigate the relationship of smoking to choroidal neovascularization (CNV) secondary to presumed ocular histoplasmosis syndrome (POHS).

DESIGN

Retrospective, case-control study.

PARTICIPANTS

A total of 568 patients 18 to 50 years of age, 142 of whom were diagnosed with CNV secondary to POHS in a private retina practice between July 1, 2000, and August 1, 2010. Four hundred twenty-six were controls selected from a private comprehensive ophthalmology practice at the same location.

METHODS

A retrospective medical record review was performed for all participants. Age, gender, zip code, CNV diagnosis date, insurance status, and smoking status at CNV diagnosis date were collected first for the POHS patients. For each of these 142 patients, 3 randomly selected comprehensive clinic patients, whose visit date fell within 3 months of the corresponding POHS patient's CNV diagnosis date, served as controls. Age, gender, zip code, visit date, reason for visit, insurance type, and smoking status were recorded. Descriptive statistics were calculated for cases and controls.

MAIN OUTCOME MEASURES

Logistic regression analyses were performed for both univariate and multivariate models, with CNV secondary to POHS as the main outcome variable and smoking as the main predictor variable, while adjusting for age, gender, insurance type, median household income, and education level.

RESULTS

The mean age of patients with CNV secondary to POHS was 39.0±7.1 years, whereas that of the control patients was 35.7±9.1 years. Of the patients with CNV secondary to POHS, 47.2% were current or former smokers (42.3% current, 4.9% former). Of the control patients, 22.5% were current or former smokers (21.8% current, 0.7% former). Age, insurance type, median income, educational attainment, and smoking status were significant in the univariate models. In the final adjusted logistic regression model, only age (odds ratio [OR], 1.04; 95% confidence interval [CI], 1.02-1.07; P = 0.001), level of educational attainment by zip code (OR, 0.95; 95% CI, 0.92-0.98; P = 0.001) and smoking status (OR, 2.83; 95% CI, 1.86-4.31; P<0.0001) were significant.

CONCLUSIONS

The odds of a smoker having CNV secondary to POHS are almost 3 times that of a nonsmoker. In this study, the odds of having CNV secondary to POHS increased with age and decreased with increasing level of educational attainment.

Update on the role of genetics in the onset of age-related macular degeneration

Age-related macular degeneration (AMD), akin to other common age-related diseases, has a complex pathogenesis and arises from the interplay of genes, environmental factors, and personal characteristics. The past decade has seen very significant strides towards identification of those precise genetic variants associated with disease. That genes encoding proteins of the (alternative) complement pathway (CFH, C2, CFB, C3, CFI) are major players in etiology came as a surprise to many but has already lead to the development of therapies entering human clinical trials. Other genes replicated in many populations ARMS2, APOE, variants near TIMP3, and genes involved in lipid metabolism have also been implicated in disease pathogenesis. The genes discovered to date can be estimated to account for approximately 50% of the genetic variance of AMD and have been discovered by candidate gene approaches, pathway analysis, and latterly genome-wide association studies. Next generation sequencing modalities and meta-analysis techniques are being employed with the aim of identifying the remaining rarer but, perhaps, individually more significant sequence variations, linked to disease status. Complementary studies have also begun to utilize this genetic information to develop clinically useful algorithms to predict AMD risk and evaluate pharmacogenetics. In this article, contemporary commentary is provided on rapidly progressing efforts to elucidate the genetic pathogenesis of AMD as the field stands at the end of the first decade of the 21st century.

Smoking and visual impairment among older adults with age-related eye diseases

INTRODUCTION

Tobacco use is the leading preventable cause of death in the United States. Visual impairment, a common cause of disability in the United States, is associated with shorter life expectancy and lower quality of life. The relationship between smoking and visual impairment is not clearly understood. We assessed the association between smoking and visual impairment among older adults with age-related eye diseases.

METHODS

We analyzed Behavioral Risk Factor Surveillance System data from 2005 through 2008 on older adults with age-related eye diseases (cataract, glaucoma, age-related macular degeneration, and diabetic retinopathy; age ≥50 y, N = 36,522). Visual impairment was defined by self-reported difficulty in recognizing a friend across the street or difficulty in reading print or numbers. Current smokers were respondents who reported having smoked at least 100 cigarettes ever and still smoked at the time of interview. Former smokers were respondents who reported having ever smoked at least 100 cigarettes but currently did not smoke. We used multivariate logistic regressions to examine the association and to adjust for potential confounders.

RESULTS

Among respondents with age-related eye diseases, the estimated prevalence of visual impairment was higher among current smokers (48%) than among former smokers (41%, P < .05) and respondents who had never smoked (42%, P < .05). After adjustment for age, sex, race/ethnicity, education, and general health status, current smokers with age-related eye diseases were more likely to have visual impairment than respondents with age-related eye diseases who had never smoked (odds ratio, 1.16, P < .05). Furthermore, respondents with cataract who were current smokers were more likely to have visual impairment than respondents with cataract who had never smoked (predictive margin, 44% vs 40%, P = .03), and the same was true for respondents with age-related macular degeneration (65% of current smokers vs 57% of never smokers, P = .02). This association did not hold true among respondents with glaucoma or diabetic retinopathy.

CONCLUSION

Smoking is linked to self-reported visual impairment among older adults with age-related eye diseases, particularly cataract and age-related macular degeneration. Longitudinal evaluation is needed to assess smoking cessation's effect on vision preservation.

Prevalence and risks factors of age-related macular degeneration in Oklahoma Indians: the Vision Keepers Study

OBJECTIVE

To determine the prevalence of age-related macular degeneration (AMD) and to identify its risk factors in an Oklahoma Indian population.

DESIGN

Cross-sectional study design.

PARTICIPANTS

Included 1019 Oklahoma Indians who participated in baseline and second examinations of the Strong Heart Study.

METHODS

Retinal photographs of at least 1 eye were obtained and graded for AMD by the University of Wisconsin Ocular Epidemiology Reading Center. Retinal photographs of 986 participants were considered gradable and were included in the study.

MAIN OUTCOME MEASURES

Age-related macular degeneration (early and late).

RESULTS

The overall prevalence of AMD in the study was 35.2%, including a prevalence of 0.81% for late AMD. The prevalence of early AMD increased from 30.6% in those aged 48 to 59 years to 46.1% in those 70 to 82 years of age. When potential risk factors were analyzed individually (univariate analyses), men with hypertension had a significantly higher prevalence of AMD (P = 0.02) than those without hypertension. In women, high-density lipoprotein cholesterol and sun exposure were associated positively with the prevalence of AMD (P = 0.01), whereas a history of using multivitamins was associated with lower AMD prevalence (P = 0.005). When multiple risk factors were analyzed simultaneously using logistic regression, only age showed significant association with AMD in both men (P = 0.02) and women (P<0.0001) and was the only significant risk factor in men. In women, multivitamin use and total cholesterol had a significant inverse association with AMD, whereas sun exposure and high-density lipoprotein cholesterol had a positive association. When men and women were combined, age and high-density lipoprotein cholesterol had significant positive associations, whereas total cholesterol, multivitamin use, and current alcohol use showed a significant inverse association with AMD.

CONCLUSIONS

This study was the first to report a detailed prevalence of AMD in Oklahoma Indians and its risk factors. The prevalence seemed to be relatively high compared with that in other ethnic groups. Some of the modifiable risk factors identified confirmed previous findings and can be used to design preventive programs to reduce the burden of AMD, although longitudinal data are still needed.

LOC387715/HTRA1 gene polymorphisms and susceptibility to age-related macular degeneration: A HuGE review and meta-analysis

PURPOSE

To examine the association of age-related macular degeneration (AMD) with HtrA serine peptidase 1 (HTRA1) gene rs11200638 G→A polymorphism and LOC387715/ ARMS2 gene rs10490924 G→T polymorphisms, and to evaluate the magnitude of the gene effect and the possible genetic mode of action.

METHODS

We searched the US National Library of Medicine's PubMed, Embase, OMIM, ISI Web of Science, and CNKI databases in a systematic manner to retrieve all genetic association studies on the HTRA1 (rs11200638) and LOC387715/ ARMS2 (rs10490924) gene polymorphisms and AMD. We performed a meta-analysis conducted with Stata software, version 9.0.

RESULTS

Individuals who carried the AA and AG genotypes of HTRA1 gene rs11200638 G→A polymorphism had 2.243 and 8.669 times the risk of developing AMD, respectively, when compared with those who carry the GG genotype. Individuals carrying the TT and TG genotypes of LOC387715/ ARMS2 gene rs10490924 G→T polymorphism had 7.512 and 2.353 times the risk of developing AMD, respectively, compared with those who carry GG genotype. These results suggested a "moderate" codominant, multiplicative genetic mode; that is, both HTRA1 rs11200638 G→A polymorphism and LOC387715/ARMS2 rs10490924 G→T polymorphism play important roles in the pathogenesis of AMD. We found no evidence of publication bias. Between-study heterogeneity was found in both allele-based analysis and genotype-based analysis.

CONCLUSIONS

HTRA1 rs11200638 G→A polymorphism and LOC387715/ARMS2 rs10490924 G→T polymorphism play important roles in AMD. Gene-gene and gene-environmental interactions, as well as precise mechanisms underlying common variants in the HTRA1 gene and LOC387715/ ARMS2 gene, potentially increase the risk of AMD and need further exploration.

Predictive, preventive and personalised medicine for age-related macular degeneration

Age-related macular degeneration (AMD) is an ophthalmologic disease which usually affects older adults and represents the leading cause of legal blindness in Europe and the United States of America. The pathogenesis of AMD is complex and, nowadays, the treatments are targeting more the late form of the disease. Age and genetic make-up are the most important risk factors identified to date. There are undoubtedly environmental and other risk factors involved and the adverse effect of smoking is well established. New treatments for AMD have emerged with improved prognostic outcome. This remarkable advances in our understanding of the genetic and biological foundations of this disease were derived from a recent convergence of scientific and clinical data. In the near future we will have several therapeutic options for treatment of AMD at different stages and therefore personalising more and more the treatment.

Metabolomic analysis of human disease and its application to the eye

Metabolomics, the analysis of the metabolite profile in body fluids or tissues, is being applied to the analysis of a number of different diseases as well as being used in following responses to therapy. While genomics involves the study of gene expression and proteomics the expression of proteins, metabolomics investigates the consequences of the activity of these genes and proteins. There is good reason to think that metabolomics will find particular utility in the investigation of inflammation, given the multi-layered responses to infection and damage that are seen. This may be particularly relevant to eye disease, which may have tissue specific and systemic components. Metabolomic analysis can inform us about ocular or other body fluids and can therefore provide new information on pathways and processes involved in these responses. In this review, we explore the metabolic consequences of disease, in particular ocular conditions, and why the data may be usefully and uniquely assessed using the multiplexed analysis inherent in the metabolomic approach.

Smoking history and the incidence of age-related macular degeneration--results from the Muenster Aging and Retina Study (MARS) cohort and systematic review and meta-analysis of observational longitudinal studies

To compare the association of smoking with age-related macular degeneration (AMD) in the Muenster Aging and Retina Study (MARS) cohort with current evidence. Adjusted risk ratios for incident AMD in MARS were compared with findings of a systematic review and meta-analysis of observational prospective studies. 9.6% of MARS participants progressed to AMD over a median of 30.9 months. In MARS the adjusted risk ratio in current versus never smokers was 3.25 (95% confidence interval [1.50-7.06]), and 1.28 [0.70-2.33] in former smokers versus never smokers. The meta-analysis of previous studies showed a pooled adjusted risk ratio of 2.51 [1.09-5.76] in current versus never smokers. Inclusion of the MARS findings removed between-study heterogeneity and accentuated the pooled adjusted risk ratio for current smokers to 2.75 [1.52-4.98]. Specific analyses in MARS revealed a protective effect for time since smoking cessation in former smokers with an adjusted risk ratio=0.50 [0.29-0.89] per log(year). Current smoking nearly triples AMD incidence, while smoking cessation lowers AMD incidence in a non-linear fashion even in the elderly.

Blue-blocking IOLs decrease photoreception without providing significant photoprotection

Violet and blue light are responsible for 45% of scotopic, 67% of melanopsin, 83% of human circadian (melatonin suppression) and 94% of S-cone photoreception in pseudophakic eyes (isoilluminance source). Yellow chromophores in blue-blocking intraocular lenses (IOLs) eliminate between 43 and 57% of violet and blue light between 400 and 500 nm, depending on their dioptric power. This restriction adversely affects pseudophakic photopic luminance contrast, photopic S-cone foveal threshold, mesopic contrast acuity, scotopic short-wavelength sensitivity and circadian photoreception. Yellow IOL chromophores provide no tangible clinical benefits in exchange for the photoreception losses they cause. They fail to decrease disability glare or improve contrast sensitivity. Most epidemiological evidence shows that environmental light exposure and cataract surgery are not significant risk factors for the progression of age-related macular degeneration (AMD). Thus, the use of blue-blocking IOLs is not evidence-based medicine. Most AMD occurs in phakic adults over 60 years of age, despite crystalline lens photoprotection far greater than that of blue-blocking IOLs. Therefore, if light does play some role in the pathogenesis of AMD, then 1) senescent crystalline lenses do not prevent it, so neither can blue-blocking IOLs that offer far less photoprotection, and 2) all pseudophakes should wear sunglasses in bright environments. Pseudophakes have the freedom to remove their sunglasses for optimal photoreception whenever they choose to do so, provided that they are not encumbered permanently by yellow IOL chromophores. In essence, yellow chromophores are placebos for prevention of AMD that permanently restrict a pseudophake's dim light and circadian photoreception at ages when they are needed most. If yellow IOLs had been the standard of care, then colorless UV-blocking IOLs could be advocated now as "premium" IOLs because they offer dim light and circadian photoreception roughly 15-20 years more youthful than blue-blocking IOLs.

Toll-like receptor polymorphisms and age-related macular degeneration: replication in three case-control samples

PURPOSE

Innate immunity appears to play a key role in age-related macular degeneration (AMD). Although two previous studies reported that gene variations in Toll-like receptor (TLR)-3 and -4 are associated with AMD, other studies have not confirmed these associations. In this study, three independent samples (two U.S. clinic-based case-control study samples and one Australian population-based study sample) were used to further assess the association of the polymorphisms rs3775291 in TLR3 and rs4986790 in TLR4 with AMD.

METHODS

AMD cases and unrelated controls were collected from the National Eye Institute Clinical Center (NEI, n = 320), the Age-Related Eye Disease Study (AREDS, n = 483), and the Blue Mountains Eye Study (BMES, n = 852). DNA extracted from subjects was genotyped for rs3775291 and rs4986790, and the associations with AMD were investigated.

RESULTS

Neither of the two polymorphisms rs3775291 and rs4986790 had a statistically significant association with AMD in any of the three sample sets or in combinations of the sets. Analysis of the combined geographic atrophy or neovascular AMD cases in the NEI, AREDS, and BMES sample sets also failed to demonstrate statistically significant associations of those two single nucleotide polymorphisms with advanced AMD.

CONCLUSIONS

Even with previously verified samples sets and adequate study powers, the results did not confirm the reported associations of TLR3 rs3775291 and TLR4 rs4986790 with AMD in the three independent samples, individually or combined.