Prevalence of age-related macular degeneration in 4 racial/ethnic groups in the multi-ethnic study of atherosclerosis

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.

THE ASSOCIATION BETWEEN CUTICULAR DRUSEN AND KIDNEY FUNCTION: A Population-Based Case-Control Study

PURPOSE

To determine the association between cuticular drusen (CD) and kidney function.

DESIGN

observational case-control study.

METHODS

SETTING

Population-based. Patients or Study Population: 53 participants with (CD) and 53 age- and sex-matched controls, selected from the Danish Rural Eye Study. Cuticular drusen participants were diagnosed using fluorescein angiography and controls were excluded if the patients were suspected of having CD on fundus photography or did not have an available estimated glomerular filtration rate.

MAIN OUTCOME MEASURES

creatinine and estimated glomerular filtration rate.

RESULTS

The mean estimated glomerular filtration rate of those with CD was 73.3 mL·min·1.73 m (95% confidence interval [CI]: 70.0-76.6) and 73.4 mL·minute·1.73 m (95% CI: 69.5-77.3) in controls. The difference was not significant (P: 0.970). The mean creatinine among those with CD was 72.8 μmol/L (69.3-76.4) and 73.5 μmol/L (95% CI: 69.3-77.6) among controls. The difference was not significant (P = 0.820).

CONCLUSION

The authors did not find an association between a (CD) diagnosis and decreased kidney function at a population level.

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.

Visual Impairment in White, Chinese, Black, and Hispanic Participants from the Multi-Ethnic Study of Atherosclerosis Cohort

PURPOSE

To describe the prevalence of visual impairment and examine its association with demographic, socioeconomic, and health characteristics in the Multi-Ethnic Study of Atherosclerosis (MESA) cohort.

METHODS

Visual acuity data were obtained from 6134 participants, aged 46-87 years at time of examination between 2002 and 2004 (mean age 64 years, 47.6% male), from six communities in the United States. Visual impairment was defined as presenting visual acuity 20/50 or worse in the better-seeing eye. Risk factors were included in multivariable logistic regression models to determine their impact on visual impairment for men and women in each racial/ethnic group.

RESULTS

Among all participants, 6.6% (n = 421) had visual impairment, including 5.6% of men (n = 178) and 7.5% of women (n = 243). Prevalence of impairment ranged from 4.2% (n = 52) and 6.0% (n = 77) in white men and women, respectively, to 7.6% (n = 37) and 11.6% (n = 44) in Chinese men and women, respectively. Older age was significantly associated with visual impairment in both men and women, particularly in those with lower socioeconomic status, but the effects of increasing age were more pronounced in men. Two-thirds of participants already wore distance correction, and not unexpectedly, a lower prevalence of visual impairment was seen in this group; however, 2.4% of men and 3.5% of women with current distance correction had correctable visual impairment, most notably among seniors.

CONCLUSION

Even in the U.S. where prevalence of refractive correction is high, both visual impairment and uncorrected refractive error represent current public health challenges.

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.

Mining Retrospective Data for Virtual Prospective Drug Repurposing: L-DOPA and Age-related Macular Degeneration

BACKGROUND

Age-related macular degeneration (AMD) is a leading cause of visual loss among the elderly. A key cell type involved in AMD, the retinal pigment epithelium, expresses a G protein-coupled receptor that, in response to its ligand, L-DOPA, up-regulates pigment epithelia-derived factor, while down-regulating vascular endothelial growth factor. In this study we investigated the potential relationship between L-DOPA and AMD.

METHODS

We used retrospective analysis to compare the incidence of AMD between patients taking vs not taking L-DOPA. We analyzed 2 separate cohorts of patients with extensive medical records from the Marshfield Clinic (approximately 17,000 and approximately 20,000) and the Truven MarketScan outpatient and databases (approximately 87 million) patients. We used International Classification of Diseases, 9th Revision codes to identify AMD diagnoses and L-DOPA prescriptions to determine the relative risk of developing AMD and age of onset with or without an L-DOPA prescription.

RESULTS

In the retrospective analysis of patients without an L-DOPA prescription, AMD age of onset was 71.2, 71.3, and 71.3 in 3 independent retrospective cohorts. Age-related macular degeneration occurred significantly later in patients with an L-DOPA prescription, 79.4 in all cohorts. The odds ratio of developing AMD was also significantly negatively correlated by L-DOPA (odds ratio 0.78; confidence interval, 0.76-0.80; P <.001). Similar results were observed for neovascular AMD (P <.001).

CONCLUSIONS

Exogenous L-DOPA was protective against AMD. L-DOPA is normally produced in pigmented tissues, such as the retinal pigment epithelium, as a byproduct of melanin synthesis by tyrosinase. GPR143 is the only known L-DOPA receptor; it is therefore plausible that GPR143 may be a fruitful target to combat this devastating disease.

Incidence of Age-Related Macular Degeneration in a Multi-Ethnic United States Population: The Multi-Ethnic Study of Atherosclerosis

PURPOSE

To describe the incidence of age-related macular degeneration (AMD) and associated risk factors in 4 racial/ethnic groups (white, black, Hispanic, and Chinese) residing in the United States.

DESIGN

Prospective cohort study.

PARTICIPANTS

A total of 3811 participants, aged 46 to 86 years, from the Multi-Ethnic Study of Atherosclerosis (MESA) cohort, with retinal data collected twice, on average, 8 years apart.

METHODS

Fundus images, taken using a digital camera through dark-adapted pupils using a standard protocol and the same equipment at both study visits, were graded centrally for early and late AMD on the basis of drusen size, type and area, increased retinal pigment, retinal pigment epithelial depigmentation, neovascular lesions, and geographic atrophy using the modified Wisconsin Age-Related Maculopathy Grading System. Demographic, clinical, and laboratory measures were included in multivariable regression models to determine their impact on the variation in AMD incidence among racial/ethnic groups.

MAIN OUTCOME MEASURES

Incident early and late AMD.

RESULTS

The overall 8-year age- and sex-standardized incidence of early and late AMD were 4.1% and 2.3%, respectively, with incidence of early and late AMD highest in whites (5.3% and 4.1%, respectively), intermediate in Chinese (4.5% and 2.2%, respectively) and Hispanics (3.3% and 0.8%, respectively), and lowest in blacks (1.6% and 0.4%, respectively). By adjusting for age and sex, blacks had a 70% lower risk of developing early AMD than whites, and this decreased only slightly to a 67% lower risk after multivariable adjustment. By adjusting for age, sex, and race/ethnicity, hyperopia was associated with early AMD (odds ratio [OR], 1.51; 95% confidence interval [CI], 1.04-2.20), as was astigmatism (OR, 1.47; 95% CI, 1.00-2.16), but not myopia (P = 0.29). Age, race/ethnicity, current smoking, hyperopia, and AMD-susceptibility genotypes Complement Factor H (CFH) RS1061170 and Age Related Maculopathy Susceptibility 2 (ARMS2) RS3793917 were independently associated with incident early AMD in multivariable models for the combined sample. However, the only statistically significant factor consistently associated with incident early AMD across the 4 racial/ethnic groups was increasing age. Risk factors for late AMD were not assessed because of its low incidence, particularly across racial/ethnic groups.

CONCLUSIONS

Variation in the incidence of early AMD exists among racial/ethnic groups in the United States and is not explained by the clinical, genetic, and environmental factors included in this study.

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.

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

PURPOSE

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

DESIGN

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Age-Related Macular Degeneration and Coronary Artery Disease in a VA Population

OBJECTIVES

Age-related macular degeneration (AMD) is the leading cause of blindness in the United States. Although AMD shares multiple risk factors with coronary artery disease (CAD), the association between AMD and CAD has not been established. The objective of our study was to demonstrate an association between the diagnosis of AMD and CAD and/or major cardiovascular risk factors.

METHODS

We performed a retrospective chart review of >13,000 patients at the Lexington Veterans Affairs Medical Center. Patients diagnosed as having AMD served as cases, and patients diagnosed with cataract and no AMD served as controls. We examined the prevalence of CAD and associated risk factors in both groups using univariate analysis followed by multivariate analyses to examine the association between AMD and CAD after adjusting for known common risk factors.

RESULTS

We identified 3950 patients with AMD and 9166 controls. Patients with AMD were on average 6 years older than controls (P < 0.001) and had a significantly higher prevalence of CAD (39% vs 34%) and hypertension (88% vs 83%) but lower incidence of diabetes mellitus and smoking. Estimated odds ratio relating CAD to AMD was 1.22 (95% confidence interval 1.13-1.32; P < 0.001). The association between CAD and AMD remained significant in multivariate analyses in older individuals (76 years and older). When we conducted a secondary analysis and matched the AMD and non-AMD groups based on age, the association between CAD and AMD remained significant (39.4% in the AMD group vs 36.6% in the non-AMD group; P = 0.011).

CONCLUSIONS

These findings support the existence of an association between CAD and AMD, particularly in older adult patients in the predominantly male Veterans Affairs population. Such an association between AMD and systemic vascular disease justifies the potential coscreening for these conditions.

Switching to less expensive blindness drug could save medicare part B $18 billion over a ten-year period

The biologic drugs bevacizumab and ranibizumab have revolutionized treatment of diabetic macular edema and neovascular age-related macular degeneration, leading causes of blindness. Ophthalmologic use of these drugs has increased and now accounts for roughly one-sixth of the Medicare Part B drug budget. The two drugs have similar efficacy and potentially minor differences in adverse-event rates; however, at $2,023 per dose, ranibizumab costs forty times more than bevacizumab. Using modeling methods, we predict ten-year (2010-20) population-level costs and health benefits of using bevacizumab and ranibizumab. Our results show that if all patients were treated with the less expensive bevacizumab instead of current usage patterns, savings would amount to $18 billion for Medicare Part B and nearly $5 billion for patients. With an additional $6 billion savings in other health care expenses, the total savings would be almost $29 billion. Altering patterns of use with these therapies by encouraging bevacizumab use and hastening approval of biosimilar therapies would dramatically reduce spending without substantially affecting patient outcomes.

Vitamin D Deficiency in Community-Dwelling Elderly Is Not Associated with Age-Related Macular Degeneration

BACKGROUND

Elderly persons are at elevated risk of vitamin D deficiency, which is involved in various health problems. However, its relation with age-related macular degeneration (AMD) is debated.

OBJECTIVES

We investigated factors associated with plasma 25-hydroxyvitamin D [25(OH)D] deficiency and the associations between plasma 25(OH)D concentrations and AMD in elderly subjects.

METHODS

Antioxydants, Lipides Essentiels, Nutrition et maladies OculaiRes (ALIENOR) is a population-based study on eye diseases performed in elderly residents of Bordeaux, France. Plasma 25(OH)D concentrations were assessed from blood samples and categorized as <25 nmol/L (deficiency), 25-49 nmol/L (insufficiency), or ≥50 nmol/L (sufficiency). AMD was classified as: no AMD, early AMD, and late AMD. Associations between baseline characteristics and plasma 25(OH)D status were examined with multinomial logistic regression analysis. Associations between AMD and plasma 25(OH)D status were estimated using generalized estimating equation logistic regressions.

RESULTS

Six hundred ninety-seven subjects with complete data were included. The prevalence of plasma 25(OH)D deficiency and insufficiency were 27.3% and 55.9%, respectively. In multivariate analysis, 25(OH)D deficiency was significantly associated with older age (P = 0.0007), females (P = 0.0007), absence of physical activity (P = 0.01), absence of vitamin D supplementation (P < 0.0001), higher plasma total cholesterol (P = 0.007), use of fibrates (P < 0.0001), lower alcohol consumption (P = 0.02), and season of blood sampling (P < 0.0001). After adjustment for these covariates and dietary omega-3 polyunsaturated fatty acid intake, smoking, and body mass index, no significant associations were found between early AMD and 25(OH)D insufficiency or deficiency (OR: 0.71, P = 0.12; OR: 0.73, P = 0.23, respectively) or with late AMD (OR: 1.04, P = 0.93; OR: 0.74, P = 0.59, respectively).

CONCLUSION

These findings underline the very high prevalence of plasma 25(OH)D deficiency in this elderly population but do not support a specific role for vitamin D in AMD.

EXTEND II: an open-label phase III multicentre study to evaluate efficacy and safety of ranibizumab in Chinese patients with subfoveal choroidal neovascularization secondary to age-related macular degeneration

PURPOSE

To evaluate the efficacy and safety of monthly ranibizumab 0.5 mg in Chinese patients with subfoveal choroidal neovascularization (CNV) secondary to neovascular age-related macular degeneration (nAMD).

METHODS

A 12-month open-label single-arm multicenter phase III study that included treatment-naïve (study eye) patients with primary/recurrent subfoveal CNV secondary to AMD. Patients (N = 114) aged ≥50 years with best-corrected visual acuity (BCVA) of 73-24 letters were treated with monthly ranibizumab for 12 months. Main outcomes were mean BCVA change from baseline to month 4 (primary endpoint) and over time to month 12, effects of ranibizumab treatment on retinal structure (months 4 and 12), and safety.

RESULTS

Ranibizumab led to significant improvements in mean BCVA ± standard error (SE) at both months 4 and 12 versus baseline (+9.5 ± 1.10 letters, 95 % confidence interval [CI] 7.3-11.7, and +12.7 ± 1.14 letters, 95 % CI 10.4-14.9, respectively, both P < 0.0001). Ranibizumab prevented loss of vision (≥0 letters BCVA gain) in 91.2 % of patients. Mean central retinal thickness ± SE reduced from baseline to month 12 (-119.9 ± 12.97 µm, 95 % CI -145.59 to -94.20, P < 0.0001). No new safety findings were reported in this study.

CONCLUSION

Ranibizumab administered monthly over 12 months was effective in improving BCVA and was well-tolerated in Chinese nAMD patients.

An evaluation of fundus photography and fundus autofluorescence in the diagnosis of cuticular drusen

PURPOSE

To examine non-mydriatic fundus photography (FP) and fundus autofluorescence (FAF) as alternative non-invasive imaging modalities to fluorescein angiography (FA) in the detection of cuticular drusen (CD).

METHODS

Among 2953 adults from the Danish Rural Eye Study (DRES) with gradable FP, three study groups were selected: (1) All those with suspected CD without age-related macular degeneration (AMD) on FP, (2) all those with suspected CD with AMD on FP and (3) a randomly selected group with early AMD. Groups 1, 2 and 3 underwent FA and FAF and group 4 underwent FAF only as part of DRES CD substudy. Main outcome measures included percentage of correct positive and correct negative diagnoses, Cohen's κ and prevalence-adjusted and bias-adjusted κ (PABAK) coefficients of test and grader reliability.

RESULTS

CD was correctly identified on FP 88.9% of the time and correctly identified as not being present 83.3% of the time. CD was correctly identified on FAF 62.0% of the time and correctly identified as not being present 100.0% of the time. Compared with FA, FP has a PABAK of 0.75 (0.60 to 1.5) and FAF a PABAK of 0.44 (0.23 to 0.95).

CONCLUSIONS

FP is a promising, non-invasive substitute for FA in the diagnosis of CD. FAF was less reliable than FP to detect CD.

Prevalence of intermediate-stage age-related macular degeneration in patients with acquired immunodeficiency syndrome

PURPOSE

To evaluate the prevalence of intermediate-stage age-related macular degeneration (AMD) in patients with acquired immunodeficiency syndrome (AIDS).

DESIGN

Cross-sectional study of patients with AIDS enrolled in the Longitudinal Study of the Ocular Complications of AIDS.

METHODS

Intermediate-stage AMD was determined from enrollment retinal photographs by graders at a centralized Reading Center, using the Age-Related Eye Disease Study grading system. Graders were masked as to clinical data.

RESULTS

Of 1825 participants with AIDS and no ocular opportunistic infections, 9.9% had intermediate-stage AMD. Risk factors included age, with an odds ratio (OR) of 1.9 (95% confidence interval [CI] 1.6, 2.3, P < .001) for every decade of age; the prevalence of AMD ranged from 4.0% for participants 30-39 years old to 24.3% for participants ≥60 years old. Other risk factors included the human immunodeficiency virus (HIV) risk groups of injection drug use (OR = 2.4, 95% CI 1.5, 3.9, P < .001) or heterosexual contact (OR = 1.9, 95% CI 1.3, 2.8, P = .001). Compared with the HIV-uninfected population in the Beaver Dam Offspring Study, there was an approximate 4-fold increased age-adjusted prevalence of intermediate-stage AMD.

CONCLUSIONS

Patients with AIDS have an increased age-adjusted prevalence of intermediate-stage AMD compared with that found in a non-HIV-infected cohort evaluated with similar methods. This increased prevalence is consistent with the increased prevalence of other age-related diseases in antiretroviral-treated, immune-restored, HIV-infected persons when compared to non-HIV-infected persons.

Single-site Baseline and Short-term Outcomes of Clinical Characteristics and Life Quality Evaluation of Chinese Wet Age-related Macular Degeneration Patients in Routine Clinical Practice

BACKGROUND

Age-related macular degeneration (AMD) is the leading cause of irreversible vision loss among the older population. In China, treatment of age-related ocular diseases is becoming a priority in eye care services. This study was to investigate the clinical characteristics and quality of life of Chinese patients with wet AMD and current treatment types, to evaluate short-term gains in different treatments, and to investigate associations between visual function and vision-related quality of life (VRQoL).

METHODS

A prospective, observational, noninterventional study was conducted. Basic data were collected from patients with clinical diagnoses of wet AMD before clinical assessments at baseline. VRQoL was measured with the Chinese version of the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25). Correlations of the NEI VFQ-25 subscale scores with best-corrected visual acuity (BCVA) and between-group differences were analyzed.

RESULTS

A total of 80 wet AMD patients were enrolled, with the mean age of 68.40 years. About one-quarter of wet AMD patients received intravitreal (IVT) ranibizumab treatment, and 67% of them were treated on a pro re nata basis. The visual acuity of patients treated with IVT ranibizumab at month 3 after treatment was significantly increased, whereas patients treated with traditional Chinese medicine achieved no significant improvement. Cronbach's α for the NEI VFQ-25 subscales ranged from 0.697 to 0.843. Eight subscale and overall composite scores were moderately correlated with the BCVA of the better-seeing eye. Significant differences in the overall NEI VFQ-25 scores and other subscales were observed between patients with BCVA in the better-seeing eye of less than 50 letters and the others.

CONCLUSIONS

Patients treated with IVT ranibizumab experienced better vision improvement at short-term follow-up. The Chinese version of the NEI VFQ-25 is a valid and reliable tool for assessing the VRQoL of Chinese wet AMD patients.

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.

Retinal thickness in black and Indian myopic students at the University of KwaZulu-Natal

Background: It has been suggested that retinal thickness varies with demographic variables. Understanding the influence of demographic variables on retinal thickness could improve our knowledge of risk factors for retinal pathologies. Previous studies have focused exclusively on white and African-American populations, with limited attention to black and Indian populations.Aim: To compare retinal thickness in black and Indian myopic students at the University of KwaZulu-Natal (UKZN).Methods: A cross-sectional comparative research design was used. The study was conducted at UKZN, Westville campus. Retinal thickness was measured in 80 healthy myopic students using the Fourier/spectral domain iVue 100 optical coherence tomographer. Retinal thickness measurements of the right and left eyes showed significant correlations, therefore data from only the right eyes were analysed. Racial and gender variations in retinal thickness of the nine Early Treatment Diabetic Retinopathy Study (ETDRS) segments were assessed.Results: The mean central foveal thickness in black participants was 238 μm compared with 243 μm in Indian participants (p = 0.06). Indian participants had thicker parafoveal thickness measurements whilst black participants had thicker perifoveal thickness measurements. Male participants had thicker retinal thickness measurements in all nine ETDRS segments than female participants. Central foveal thickness showed no significant correlation with spherical equivalent (r = -0.14, p > 0.05) or axial length (r = 0.09, p > 0.05).Conclusion: The average central foveal thickness was slightly thinner in black and female participants than in Indian and male participants. Optometrists and ophthalmologists should consider these differences when evaluating black and Indian individuals with foveal retinal diseases.

Association between neovascular age-related macular degeneration and dementia: a population-based case-control study in Taiwan

Background

Most available studies focusing on the association between neovascular age-related macular degeneration (AMD) and dementia have conflicting results. This study aimed to investigate the association between previously diagnosed AMD and dementia using a population-based dataset in Taiwan.

Methods

Data for this case-control study were retrospectively collected from the Taiwan National Health Insurance Research Database. We identified 13,402 subjects who had a diagnosis of dementia as cases, and 40,206 subjects without dementia as controls. A conditional logistic regression was used to examine the association of dementia with previously diagnosed neovascular AMD.

Results

We found that of the study sample of 53,608 subjects, 1.01% had previously diagnosed neovascular AMD, 1.35% and 0.90% for cases and the controls, respectively (p<0.001). The conditional logistic regression analysis suggested that the odds ratio of prior neovascular AMD for cases was 1.37 (95% confidence interval: 1.14~1.65) compared to the controls after adjusting for subjects’ age, monthly income, geographic location, urbanization level, and hyperlipidemia, diabetes, hypertension, stroke, ischemic heart disease, and whether or not a subjects underwent cataract surgery prior to index date than controls.

Conclusions

Dementia subjects were associated with a higher proportion of prior neovascular AMD than were the controls.

Nutrient Supplementation for Age-related Macular Degeneration, Cataract, and Dry Eye

There have been enormous advances in the past decade for the treatment of age-related macular degeneration (AMD); however, these treatments are expensive and require frequent follow-up and injections which place a tremendous burden on both the healthcare system and patients. Consequently, there remains considerable interest in preventing or slowing the progression of AMD requiring treatment. Epidemiological studies have shown that diet is a modifiable AMD risk factor, and nutrient modification is a particularly appealing treatment for AMD due to the perceived universal benefit and relatively low expense. Recently, the age-related eye disease study part two (AREDS2) was concluded and demonstrated further benefit with the addition of lutein and zeaxanthin as a replacement for the β-carotene of the previous generation formulation. The addition of omega-3 essential fatty acids did not show an added benefit. This review aims to highlight some of the evidenced based body of knowledge that has been accumulated from recent studies regarding the use of nutritional supplements and their effect on AMD, cataracts, and dry eyes.

Prevalence of age-related macular degeneration in the Republic of Ireland

Background

Age-related macular degeneration (AMD) remains the most common cause of visual loss among subjects over 50 years of age in the developed world. The Irish Longitudinal study on Ageing (TILDA) is a population-based study of subjects aged 50 years or older, designed to investigate factors that influence ageing, and has enabled this investigation of the prevalence of AMD in the Republic of Ireland (ROI).

Methods

Data collected from a nationally representative sample of community-living older adults aged 50 years and over in ROI over the period November 2009 to July 2011. 5035 participants attended the TILDA health centre for assessment. Retinal photographs were obtained in 4859 of these participants. Retinal grading was performed in a masked fashion using a modified version of the International Classification and Grading System for AMD.

Results

Adjusting for lower response rates among older subjects, the estimated overall prevalence of any AMD was 7.2% (95% CI 6.5% to 7.9%) in the population aged 50 years or older. The estimated prevalence of early AMD was 6.6% (95% CI 5.9% to 7.3%), and the estimated prevalence of late AMD was 0.6% (95% CI 0.4% to 0.8%). Statistically significant associations with AMD included increasing age and family history of the condition.

Conclusions

This is the first study to provide prevalence estimates of AMD in ROI and will inform eye care professionals and policymakers involved in the delivery and planning of care for those afflicted with this condition.

The Prevalence of Age-Related Eye Diseases and Cataract Surgery among Older Adults in the City of Lodz, Poland

Purpose. To determine the prevalence of age-related eye diseases and cataract surgery among older adults in the city of Lodz, in central Poland. Material and Methods. The study design was cross-sectional and observational study. A total of 1107 women and men of predominantly Caucasian origin were successfully enumerated and recruited for the study. All selected subjects were interviewed and underwent detailed ophthalmic examinations. Results. Overall 8.04% (95% CI 6.44-9.64) subjects had cataract surgery in either eye. After excluding subjects with bilateral cataract surgery, the prevalence of cataract was 12.10% (95% CI 10.18-14.03). AMD was found in 4.33% (95% CI 3.14-5.54 ) of all subjects. Of them 3.25% (95% CI 2.21-4.30 ) had early AMD and 1.08% (95% CI 0.47-1.69) had late AMD. Various types of glaucoma were diagnosed in 5.51% (95% CI 4.17-6.85) of subjects and 2.62% (95% CI 1.68-3.56) had OHT. The prevalence rates of DR and myopic macular degeneration were 1.72% (95% CI 0.95-2.48) and 0.45% (95% CI 0.06-0.85), respectively. All multiple logistic regression models were only significantly associated with older age. The highest rate of visual impairment was observed among subjects with retinal diseases. Conclusions. The study revealed high prevalence of age-related eye diseases in this older population.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

OBJECTIVE

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

DESIGN

Population-based prospective cohort study.

PARTICIPANTS

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

METHODS

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

MAIN OUTCOME MEASURES

Mortality resulting from all causes and CVD.

RESULTS

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

CONCLUSIONS

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

Lutein and Factor D: two intriguing players in the field of age-related macular degeneration

Age-related macular degeneration (AMD) is a progressive eye disease that impairs central vision among elderly populations in Western, industrialized countries. In this review we will focus on the role of factor D (FD) and lutein in AMD. FD is a rate-limiting enzyme of the alternative complement activation pathway that may play an important role in the development of AMD. Several independent studies have shown a significant increase in the level of a number of complement factors of the alternative pathway, including factor D in the blood of AMD patients as compared to healthy individuals, which suggests a systemic involvement in the pathogenesis of AMD. FD, also called adipsin, is mainly produced by adipose tissue. Besides playing a role in the activation of the alternative pathway, FD is also known to regulate the immune system. Of interest is our preliminary finding that lutein supplementation of early AMD cases was shown to lower the level of systemic FD. If confirmed, these findings provide further support for the application of anti-factor D intervention as a new approach to control the development of this disease.

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

Purpose

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

Methods.

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

Results.

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

Conclusion:

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

Drusen and RPE atrophy automated quantification by optical coherence tomography in an elderly population

PURPOSE

Correlate OCT-derived measures of drusen and retinal pigment epithelium (RPE) atrophy areas (RAs) with demographic features in an elderly population.

PATIENTS AND METHODS

Subjects aged 50 years and older underwent Cirrus OCT scanning. Drusen area and volume were obtained from the macula within a central circle (CC) of 3 mm and a surrounding perifoveal ring (PR) of 3-5 mm, using the RPE analysis software (6.0). RA measurements were generated for the 6 × 6 mm(2) retinal area. Gender, age, smoking status, and systolic blood pressure (SBP) were considered.

RESULTS

A total of 434 eyes were included. RA was larger in women (0.63±0.16 vs 0.26±0.08 mm(2), P=0.05) and with increasing age. The PR drusen area increased with increasing age (P<0.001), whereas the CC drusen area remained stable after the age of 70 years (0.25±0.06 mm(2) for ages 70-79 years and 0.25±0.07 mm(2) for ages >80 years). Drusen volume in the CC was smaller after the age of 80 years (0.009±0.003 mm(3)) compared with the 70- to 79-year-old group (0.02±0.008 mm(3)). Drusen measurements were similar between smokers and nonsmokers, but the PR drusen area (0.29 mm(2), P=0.05) and volume (0.40 mm(3), P=0.005) were correlated with years smoked. RA (0.24 mm(2), P=0.10), PR drusen area (0.29 mm(2), P=0.05), and volume (0.40 mm(3), P=0.005) were found to be directly associated with SBP. There was a high correlation between the eyes of the same subject.

CONCLUSION

OCT-based automated algorithms can be used to analyze and describe drusen and geographic atrophy burden in such population-based studies of elderly patients.

Current knowledge and trends in age-related macular degeneration: genetics, epidemiology, and prevention

PURPOSE

To address the most dynamic and current issues concerning human genetics, risk factors, pharmacoeconomics, and prevention regarding age-related macular degeneration.

METHODS

An online review of the database Pubmed and Ovid was performed, searching for the key words: age-related macular degeneration, AMD, pharmacoeconomics, risk factors, VEGF, prevention, genetics and their compound phrases. The search was limited to articles published since 1985 to date. All returned articles were carefully screened and their references were manually reviewed for additional relevant data. The webpage www.clinicaltrials.gov was also accessed in search of relevant research trials.

RESULTS

A total of 366 articles were reviewed, including 64 additional articles extracted from the references and 25 webpages and online databases from different institutions. At the end, only 244 references were included in this review.

CONCLUSION

Age-related macular degeneration is a complex multifactorial disease that has an uneven manifestation around the world but with one common denominator, it is increasing and spreading. The economic burden that this disease poses in developed nations will increase in the coming years. Effective preventive therapies need to be developed in the near future.

Genomic aspects of age-related macular degeneration

Age-related macular degeneration (AMD) is a major late-onset posterior eye disease that causes central vision to deteriorate among elderly populations. The predominant lesion of AMD is the macula, at the interface between the outer retina and the inner choroid. Recent advances in genetics have revealed that inflammatory and angiogenic pathways play critical roles in the pathophysiology of AMD. Genome-wide association studies have identified ARMS2/HTRA1 and CFH as major AMD susceptibility genes. Genetic studies for AMD will contribute to the prevention of central vision loss, the development of new treatment, and the maintenance of quality of vision for productive aging.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

OBJECTIVE

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

DESIGN

Population-based, prospective, cohort study.

PARTICIPANTS

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

METHODS

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

MAIN OUTCOME MEASURES

We assessed AMD, defined as early or late.

RESULTS

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

CONCLUSIONS

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

A prospective study of treatment patterns and 1-year outcome of Asian age-related macular degeneration and polypoidal choroidal vasculopathy

OBJECTIVE

To study the treatment patterns and visual outcome over one year in Asian patients with choroidal neovascular membrane secondary to age-related macular degeneration (AMD-CNV) and polypoidal choroidal vasculopathy (PCV).

DESIGN

Prospective cohort, non-interventional study.

METHODS

132 treatment-naïve patients who received treatment for AMD-CNV and PCV were included. All patients underwent standardized examination procedures including retinal imaging at baseline and follow-up. AMD-CNV and PCV were defined on fundus fluorescein angiography and indocyanine green angiography at baseline. Patients were treated according to standard of care.We report the visual acuity (VA) and optical coherence tomography (OCT) measurements at baseline, month 3 and month 12 The factors influencing month 12 outcomes were analyzed.

MAIN OUTCOME MEASURE

Type of treatment, number of Anti-vascular endothelial growth factor (VEGF) treatments, visual outcome over one year.

RESULTS

Anti-VEGF monotherapy was the initial treatment in 89.1% of AMD-CNV, but only 15.1% of PCV. The mean number of anti-VEGF injections up to month 12 was 3.97 (4.51 AMD-CNV, 3.43 PCV, p = 0.021). Baseline OCT, month 3 OCT and month 3 VA were significant in determining continuation of treatment after month 3. At month 12, mean VA improved from 0.82 (∼20/132) at baseline to 0.68 (∼20/96) at month 12 (mean gain 6.5 ETDRS letters, p = 0.002). 34.2% of eyes (38/113 eyes) gained ≥15 ETDRS letters and 14.4% (16/113 eyes) lost ≥15 ETDRS letters. There were no significant differences in visual outcome between AMD-CNV and PCV (p = 0.51). Factors predictive of month 12 visual outcome were baseline VA, baseline OCT central macular thickness, month 3 VA and age.

CONCLUSIONS

There is significant variation in treatment patterns in Asian eyes with exudative maculopathy. There is significant visual improvement in all treatment groups at one year. These data highlight the need for high quality clinical trial data to provide evidence-based management of Asian AMD.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Age-related macular degeneration: genetics and biology coming together

Genetic and genomic studies have enhanced our understanding of complex neurodegenerative diseases that exert a devastating impact on individuals and society. One such disease, age-related macular degeneration (AMD), is a major cause of progressive and debilitating visual impairment. Since the pioneering discovery in 2005 of complement factor H (CFH) as a major AMD susceptibility gene, extensive investigations have confirmed 19 additional genetic risk loci, and more are anticipated. In addition to common variants identified by now-conventional genome-wide association studies, targeted genomic sequencing and exome-chip analyses are uncovering rare variant alleles of high impact. Here, we provide a critical review of the ongoing genetic studies and of common and rare risk variants at a total of 20 susceptibility loci, which together explain 40-60% of the disease heritability but provide limited power for diagnostic testing of disease risk. Identification of these susceptibility loci has begun to untangle the complex biological pathways underlying AMD pathophysiology, pointing to new testable paradigms for treatment.

Serum carboxymethyllysine, an advanced glycation end product, and age-related macular degeneration: the Age, Gene/Environment Susceptibility-Reykjavik Study

IMPORTANCE Advanced glycation end products have been implicated in the pathogenesis of age-related macular degeneration (AMD). OBJECTIVE To investigate the relationship between serum carboxymethyllysine (CML), a major circulating advanced glycation end product, and AMD in older adults. DESIGN, SETTING, AND PARTICIPANTS Cross-sectional study of a population-based sample of 4907 older adults (aged ≥66 years) in the Age, Gene/Environment Susceptibility-Reykjavik Study in Iceland. EXPOSURES Serum CML and risk factors for AMD. MAIN OUTCOMES AND MEASURES Early or late AMD, assessed through fundus images taken through dilated pupils using a 45° digital camera and grading for drusen size, type, area, increased retinal pigment, retinal pigment epithelial depigmentation, neovascular lesions, and geographic atrophy using the modified Wisconsin Age-Related Maculopathy Grading System. RESULTS Of the 4907 participants, 1025 (20.9%) had early AMD and 276 (5.6%) had late AMD. Mean (SD) serum CML concentrations among adults with no AMD, early AMD, and late AMD (exudative AMD and pure geographic atrophy) were 618.8 (195.5), 634.2 (206.4), and 638.4 (192.0) ng/mL, respectively (to convert to micromoles per liter, multiply by 0.00489; P = .07). Log serum CML (per 1-SD increase) was not associated with any AMD (early and late AMD) (odds ratio = 0.97; 95% CI, 0.90-1.04; P = .44) or with late AMD (odds ratio = 0.94; 95% CI, 0.82-1.08; P = .36) in respective multivariable logistic regression models adjusting for age, sex, body mass index, smoking, and renal function. CONCLUSIONS AND RELEVANCE Higher serum CML concentration had no significant cross-sectional association with prevalent AMD in this large population-based cohort of older adults in Iceland.

Association study of newly identified age-related macular degeneration susceptible loci SOD2, MBP, and C8orf42 in Han Chinese population

A recent genome-wide association study has reported three newly identified susceptible loci (rs2842992 near the gene SOD2, rs1789110 near the gene MBP and rs722782 near the gene C8orf42) to be associated with the geographic atrophy subtype of age-related macular degeneration in European-descent population. We investigated the correlation between these variants and advanced age-related macular degeneration for the first time in a Han Chinese cohort; however, no evidence supports these previously identified loci contribute to advanced age-related macular degeneration susceptibility in Chinese population.

Prevalence, racial variations, and risk factors of age-related macular degeneration in Singaporean Chinese, Indians, and Malays

OBJECTIVE

To describe the prevalence and risk factors for age-related macular degeneration (AMD) in a multiethnic Asian cohort of Chinese, Malay, and Indian persons.

DESIGN

Population-based cross-sectional study.

PARTICIPANTS

A total of 10 033 persons (3280 Malay, 3400 Indian, and 3353 Chinese; response rate, 75%) 40 years of age or older residing in Singapore.

METHODS

We performed comprehensive systemic and ocular examinations, retinal photography, and laboratory investigations for all participants. We graded early and late AMD signs from retinal photographs using the modified Wisconsin AMD grading scale. We calculated the age-standardized prevalence of AMD using the 2010 Singapore adult population and analyzed risk factors for AMD using logistic regression models.

MAIN OUTCOME MEASURES

Early and late AMD.

RESULTS

Of the 9799 participants with gradable photographs, 588 had early AMD and 60 had late AMD. The age-standardized prevalence was 5.1% (95% confidence interval [CI], 4.6-5.5) for early AMD and 0.5% (95% CI, 0.4-0.6) for late AMD. The prevalence of early AMD was similar between Chinese (5.7%) and Indian (4.5%; P = 0.27) persons and lower in Malays (3.5%; P = 0.002 compared with Chinese; P = 0.09 compared with Indians); in contrast, the prevalence for late AMD was similar across ethnic groups (Chinese, 0.6%; Indian, 0.3%; and Malay, 0.3%; P = 0.20). Risk factors for early AMD were older age (odds ratio [OR], 1.40 per 5-year increase in age; 95% CI, 1.33-1.47), male gender (OR, 1.81; 95% CI, 1.43-2.29), hypertension (OR, 1.28; 95% CI, 1.02-1.61), and hyperopic refraction (OR, 1.17 per 1-diopter increase in spherical equivalent; 95% CI, 1.11-1.24). Risk factors for late AMD include older age (OR, 1.87 per 5-year increase in age; 95% CI, 1.54-2.19), smoking more than 5 packs per week (OR, 3.63; 95% CI, 1.34-9.80), and presence of chronic kidney disease (OR, 2.17; 95% CI, 1.22-3.88).

CONCLUSIONS

Early AMD is more common in Chinese and Indians than in Malays, but there were no racial variations in the prevalence of late AMD.

Elevated high-density lipoprotein cholesterol and age-related macular degeneration: the Alienor study

Background

Lipid metabolism and particularly high-density lipoprotein (HDL) may be involved in the pathogenic mechanism of age-related macular degeneration (AMD). However, conflicting results have been reported in the associations of AMD with plasma HDL and other lipids, which may be confounded by the recently reported associations of AMD with HDL-related genes. We explored the association of AMD with plasma lipid levels and lipid-lowering medication use, taking into account most of HDL-related genes associated with AMD.

Methods

The Alienor study is a population-based study on age-related eye diseases performed in 963 elderly residents of Bordeaux (France). AMD was graded from non mydriatic color retinal photographs in three exclusive stages: no AMD (n = 430 subjects, 938 eyes); large soft distinct drusen and/or large soft indistinct drusen and/or reticular drusen and/or pigmentary abnormalities (early AMD, n = 176, 247); late AMD (n = 40, 61). Associations of AMD with plasma lipids (HDL, total cholesterol (TC), Low-density lipoprotein (LDL), and triglycerides (TG)) were estimated using Generalized Estimating Equation logistic regressions. Statistical analyses included 646 subjects with complete data.

Results

After multivariate adjustment for age, sex, educational level, smoking, BMI, lipid-lowering medication use, cardiovascular disease and diabetes, and for all relevant genetic polymorphisms (ApoE2, ApoE4, CFH Y402H, ARMS2 A69S, LIPC rs10468017, LIPC rs493258, LPL rs12678919, ABCA1 rs1883025 and CETP rs3764261), higher HDL was significantly associated with an increased risk of early (OR = 2.45, 95%CI: 1.54–3.90; P = 0.0002) and any AMD (OR = 2.29, 95%CI: 1.46–3.59; P = 0.0003). Association with late AMD was far from statistical significance (OR = 1.58, 95%CI: 0.48–5.17; p = 0.45). No associations were found for any stage of AMD with TC, LDL and TG levels, statin or fibrate drug use.

Conclusions

This study suggests that elderly patients with high HDL concentration may be at increased risk for AMD and, further, that HDL dysfunction might be implicated in AMD pathogenesis.

Refractive error and risk of early or late age-related macular degeneration: a systematic review and meta-analysis

OBJECTIVE

To summarize relevant evidence investigating the associations between refractive error and age-related macular degeneration (AMD).

DESIGN

Systematic review and meta-analysis.

METHODS

We searched Medline, Web of Science, and Cochrane databases as well as the reference lists of retrieved articles to identify studies that met the inclusion criteria. Extracted data were combined using a random-effects meta-analysis. Studies that were pertinent to our topic but did not meet the criteria for quantitative analysis were reported in a systematic review instead.

MAIN OUTCOME MEASURES

Pooled odds ratios (ORs) and 95% confidence intervals (CIs) for the associations between refractive error (hyperopia, myopia, per-diopter increase in spherical equivalent [SE] toward hyperopia, per-millimeter increase in axial length [AL]) and AMD (early and late, prevalent and incident).

RESULTS

Fourteen studies comprising over 5800 patients were eligible. Significant associations were found between hyperopia, myopia, per-diopter increase in SE, per-millimeter increase in AL, and prevalent early AMD. The pooled ORs and 95% CIs were 1.13 (1.06-1.20), 0.75 (0.56-0.94), 1.10 (1.07-1.14), and 0.79 (0.73-0.85), respectively. The per-diopter increase in SE was also significantly associated with early AMD incidence (OR, 1.06; 95% CI, 1.02-1.10). However, no significant association was found between hyperopia or myopia and early AMD incidence. Furthermore, neither prevalent nor incident late AMD was associated with refractive error. Considerable heterogeneity was found among studies investigating the association between myopia and prevalent early AMD (P = 0.001, I2 = 72.2%). Geographic location might play a role; the heterogeneity became non-significant after stratifying these studies into Asian and non-Asian subgroups.

CONCLUSION

Refractive error is associated with early AMD but not with late AMD. More large-scale longitudinal studies are needed to further investigate such associations.

Age-related macular degeneration-clinical review and genetics update

Age-related macular degeneration (AMD) is the leading cause of central vision impairment in persons over the age of 50 years in developed countries. Both genetic and non-genetic (environmental) factors play major roles in AMD etiology, and multiple gene variants and lifestyle factors such as smoking have been associated with the disease. While dissecting the basic etiology of the disease remains a major challenge, current genetic knowledge has provided opportunities for improved risk assessment, molecular diagnosis and clinical testing of genetic variants in AMD treatment and management. This review addresses the potential of translating the wealth of genetic findings for improved risk prediction and therapeutic intervention in AMD patients. Finally, we discuss the recent advancement in genetics and genomics and the future prospective of personalized medicine in AMD patients.

Health resource utilization and the economic burden of patients with wet age-related macular degeneration in Thailand

AIM

To determine healthcare resource utilization and the economic burden associated with wet age-related macular degeneration (AMD) in Thailand.

METHODS

This study included patients diagnosed with wet AMD that were 60 years old or older, and had best corrected visual acuity (BCVA) measured at least two times during the follow-up period. We excluded patients having other eye diseases. Two separate sub-studies were conducted. The first sub-study was a retrospective cohort study; electronic medical charts were reviewed to estimate the direct medical costs. The second sub-study was a cross-sectional survey estimating the direct non-medical costs based on face-to-face interviews using a structured questionnaire. For the first sub-study, direct medical costs, including the cost of drugs, laboratory, procedures, and other treatments were obtained. For the second sub-study, direct non-medical costs, e.g. transportation, food, accessories, home renovation, and caregiver costs, were obtained from face-to-face interviews with patients and/or caregivers.

RESULTS

For the first sub-study, sixty-four medical records were reviewed. The annual average number of medical visits was 11.1±6.0. The average direct medical costs were $3 604±4 530 per year. No statistically-significant differences of the average direct medical costs among the BCVA groups were detected (P=0.98). Drug costs accounted for 77% of total direct medical costs. For direct non-medical costs, 67 patients were included. Forty-eight patients (71.6%) required the accompaniment of a person during the out-patient visit. Seventeen patients (25.4%) required a caregiver at home. The average direct non-medical cost was $2 927±6 560 per year. There were no statistically-significant differences in the average costs among the BCVA groups (P=0.74). Care-giver cost accounted for 87% of direct non-medical costs.

CONCLUSION

Our study indicates that wet AMD is associated with a substantial economic burden, especially concerning drug and care-giver costs.

Increased risk of Parkinson disease following a diagnosis of neovascular age-related macular degeneration: a retrospective cohort study

PURPOSE

To investigate the risk for Parkinson disease during a 3-year follow-up period after a diagnosis of neovascular age-related macular degeneration (AMD) using a nationwide population-based dataset in Taiwan.

DESIGN

A retrospective matched-cohort study.

METHODS

We identified 877subjects with neovascular AMD as the study cohort and randomly selected 8770 subjects for a comparison cohort. Each subject was individually followed for a 3-year period to identify those who subsequently developed Parkinson disease. Stratified Cox proportional hazard regressions were performed as a means of comparing the 3-year risk of subsequent Parkinson disease between the study and comparison cohorts.

RESULTS

The incidence rate of Parkinson disease was 5.32 (95% confidence interval [CI]: 3.03-8.72) per 1000 person-years in patients with neovascular AMD and 2.09 (95% CI: 1.59-2.70) per 1000 person-years in comparison patients. The log-rank test indicated that subjects with neovascular AMD had a significantly lower 3-year Parkinson disease-free survival rate than comparison subjects (P < .001). After censoring cases in which patients died during the follow-up period and adjusting for monthly income, geographic region, hypertension, diabetes, hyperlipidemia, and coronary heart disease, the hazard ratio of Parkinson disease during the 3-year follow-up period for subjects with neovascular AMD was 2.57 (95% CI: 1.42-4.64) that of comparison subjects.

CONCLUSION

In this study, subjects with neovascular AMD were found to be at a significant risk of Parkinson disease during a 3-year follow-up period after their diagnosis among Taiwanese Chinese. Further study is needed to confirm our findings and explore the underlying pathomechanism.

Improving access to optometry services for people at risk of preventable sight loss: a qualitative study in five UK locations

Background

Reducing preventable sight loss is an increasing priority for public health and health care providers. We examined the factors affecting people's use of optometry services in population groups at increased risk of sight loss.

Methods

This is a qualitative study in five UK locations. In England, participants were from the Pakistani and Black Caribbean communities; in Scotland from the Pakistani community; and in Northern Ireland and Wales from white socio-economically deprived communities. Thirty-four focus groups were conducted (n = 289). The study included people who attend optometry services and people not engaged with services.

Results

Barriers to access included limited awareness of eye health and eye disease, concern about the cost of spectacles and the appropriateness of optometry in a commercial setting. Attendance at the optometrist was primarily symptom led. A positive previous experience or continuing relationship with the optometrist helped to alleviate the barriers and promote attendance.

Conclusion

Addressing the disparity between the broader messages about eye health and the current perception of the function of optometry could help improve access to services. Uptake may be improved through the co-production of interventions that better resonate with local communities. Non-retail service delivery options should be explored.

Global prevalence of age-related macular degeneration and disease burden projection for 2020 and 2040: a systematic review and meta-analysis

BACKGROUND

Numerous population-based studies of age-related macular degeneration have been reported around the world, with the results of some studies suggesting racial or ethnic differences in disease prevalence. Integrating these resources to provide summarised data to establish worldwide prevalence and to project the number of people with age-related macular degeneration from 2020 to 2040 would be a useful guide for global strategies.

METHODS

We did a systematic literature review to identify all population-based studies of age-related macular degeneration published before May, 2013. Only studies using retinal photographs and standardised grading classifications (the Wisconsin age-related maculopathy grading system, the international classification for age-related macular degeneration, or the Rotterdam staging system) were included. Hierarchical Bayesian approaches were used to estimate the pooled prevalence, the 95% credible intervals (CrI), and to examine the difference in prevalence by ethnicity (European, African, Hispanic, Asian) and region (Africa, Asia, Europe, Latin America and the Caribbean, North America, and Oceania). UN World Population Prospects were used to project the number of people affected in 2014 and 2040. Bayes factor was calculated as a measure of statistical evidence, with a score above three indicating substantial evidence.

FINDINGS

Analysis of 129,664 individuals (aged 30-97 years), with 12,727 cases from 39 studies, showed the pooled prevalence (mapped to an age range of 45-85 years) of early, late, and any age-related macular degeneration to be 8.01% (95% CrI 3.98-15.49), 0.37% (0.18-0.77), and 8.69% (4.26-17.40), respectively. We found a higher prevalence of early and any age-related macular degeneration in Europeans than in Asians (early: 11.2% vs 6.8%, Bayes factor 3.9; any: 12.3% vs 7.4%, Bayes factor 4.3), and early, late, and any age-related macular degeneration to be more prevalent in Europeans than in Africans (early: 11.2% vs 7.1%, Bayes factor 12.2; late: 0.5% vs 0.3%, 3.7; any: 12.3% vs 7.5%, 31.3). There was no difference in prevalence between Asians and Africans (all Bayes factors <1). Europeans had a higher prevalence of geographic atrophy subtype (1.11%, 95% CrI 0.53-2.08) than Africans (0.14%, 0.04-0.45), Asians (0.21%, 0.04-0.87), and Hispanics (0.16%, 0.05-0.46). Between geographical regions, cases of early and any age-related macular degeneration were less prevalent in Asia than in Europe and North America (early: 6.3% vs 14.3% and 12.8% [Bayes factor 2.3 and 7.6]; any: 6.9% vs 18.3% and 14.3% [3.0 and 3.8]). No significant gender effect was noted in prevalence (Bayes factor <1.0). The projected number of people with age-related macular degeneration in 2020 is 196 million (95% CrI 140-261), increasing to 288 million in 2040 (205-399).

INTERPRETATION

These estimates indicate the substantial global burden of age-related macular degeneration. Summarised data provide information for understanding the effect of the condition and provide data towards designing eye-care strategies and health services around the world.

FUNDING

National Medical Research Council, Singapore.

Dietary and lifestyle risk factors associated with age-related macular degeneration: a hospital based study

AIM

To establish the frequency, associations and risk factors for age-related macular degeneration (AMD) in hospital population of South India.

MATERIALS AND METHODS

In this cross-sectional hospital based study, 3549 subjects (2090 men and 1459 women) above 45 years of age were screened randomly for AMD. Participants underwent ocular evaluation and were interviewed for lifestyle variables and dietary intake of carotenoids by structured food frequency questionnaire. AMD was defined according to the international classifications and grading system.

RESULTS

Either form of AMD was detected in 77 (2.2%) participants. Of which, early and late AMD was present in 63 (1.8%) and 14 (0.4%) subjects, respectively. Binary logistic analysis showed that the incidence of AMD was significantly higher with increasing age (Odds ratio [OR] 1.17; 95% CI 1.13-1.22) and diabetes (OR 3.97; 95% CI 2.11-7.46). However, AMD was significant among heavy cigarette smokers (OR 5.58; 95% CI 0.88-7.51) and alcoholics (OR 4.85; 95% CI 2.45-12.22). Dietary lutein/zeaxanthin (L/Z) and β-carotene intake were associated (P < 0.001) with the reduction in risk for AMD, with an OR of 0.38 and 0.65, respectively.

CONCLUSIONS

Higher dietary intake of carotenoids, especially L/Z, was associated with lower risk for AMD. Risk of AMD is higher with increasing age and was prevalent among subjects with diabetes. Cessation of smoking and alcohol may reduce the risk of AMD in this population.