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

Prevalence and characteristics of age-related macular degeneration in the Japanese population: the Nagahama study

PURPOSE

To estimate the age- and sex-specific prevalence of early age-related macular degeneration (AMD; drusen and retinal pigment abnormalities) and late AMD (exudative AMD and geographic atrophy) in the Japanese population.

DESIGN

Community-based, cross-sectional study.

METHODS

The study was held in Nagahama, Japan, and included 6065 Japanese individuals (aged ≥50 years) recruited in 2008-2010. We graded fundus photographs of both eyes for the AMD phenotype based on drusen size, the presence of retinal pigment abnormalities, and late AMD. The associations between smoking and AMD phenotypes were also evaluated.

RESULTS

We assessed 5595 subjects (women, 65%) with a gradable macular condition. Early and late AMD prevalence increased from 16.1% and 0.27% at 50-59 years to 31.2% and 0.98%, respectively, at 70-74 years and was predominant in male subjects in each age group. Smoking was associated with both early and late AMD stages and retinal pigment abnormalities (P < .0001), but not with drusen (P = .305). The prevalence of retinal pigment abnormalities was significantly higher in men (P < .0001), which was associated with high rates of cigarette smoking. We found no sex difference for the prevalence of large drusen (P = .264).

CONCLUSIONS

The prevalence of early AMD among adult Japanese persons was similar to the rates in white populations. The prevalence of late AMD in Japanese people aged <70 years was similar to that observed in white populations, whereas that in Japanese people aged ≥70 years was relatively lower.

Is household air pollution a risk factor for eye disease?

In developing countries, household air pollution (HAP) resulting from the inefficient burning of coal and biomass (wood, charcoal, animal dung and crop residues) for cooking and heating has been linked to a number of negative health outcomes, mostly notably respiratory diseases and cancers. While ocular irritation has been associated with HAP, there are sparse data on adverse ocular outcomes that may result from acute and chronic exposures. We consider that there is suggestive evidence, and biological plausibility, to hypothesize that HAP is associated with some of the major blinding, and painful, eye conditions seen worldwide. Further research on this environmental risk factor for eye diseases is warranted.

The chinese american eye study: design and methods

PURPOSE

To summarize the study design, operational strategies and procedures of the Chinese American Eye Study (CHES), a population-based assessment of the prevalence of visual impairment, ocular disease, and visual functioning in Chinese Americans.

METHODS

This population-based, cross-sectional study included 4570 Chinese participants aged 50 years and older, residing in the city of Monterey Park, California. Each eligible participant completed a detailed interview and eye examination. The interview included an assessment of demographic, behavioral and ocular risk factors and health-related and vision-related quality of life. The eye examination included measurements of visual acuity, intraocular pressure, visual fields, fundus and optic disc photography, a detailed anterior and posterior segment examination, and measurements of blood pressure, glycosylated hemoglobin levels, and blood glucose levels.

RESULTS

The objectives of the CHES are to obtain prevalence estimates of visual impairment, refractive error, diabetic retinopathy, open-angle and angle-closure glaucoma, lens opacities, and age-related macular degeneration in Chinese Americans. In addition, outcomes include effect estimates for risk factors associated with eye diseases. Lastly, CHES will investigate the genetic determinants of myopia and glaucoma.

CONCLUSION

The CHES will provide information about the prevalence and risk factors of ocular diseases in one of the fastest growing minority groups in the United States.

A systematic review of overweight, obesity, and type 2 diabetes among Asian American subgroups

This systematic review synthesizes data published between 1988 and 2009 on mean BMI and prevalence of overweight, obesity, and type 2 diabetes among Asian subgroups in the U.S. We conducted systematic searches in Pub- Med for peer-reviewed, English-language citations that reported mean BMI and percent overweight, obesity, and diabetes among South Asians/Asian Indians, Chinese, Filipinos, Koreans, and Vietnamese. We identified 647 database citations and 23 additional citations from hand-searching. After screening titles, abstracts, and full-text publications, 97 citations remained. None were published between 1988 and 1992, 28 between 1993 and 2003, and 69 between 2004 and 2009. Publications were identified for the following Asian subgroups: South Asian (n=8), Asian Indian (n=20), Chinese (n=44), Filipino (n=22), Korean (n= 8), and Vietnamese (n=3). The observed sample sizes ranged from 32 to 4245 subjects with mean ages from 24 to 78 years. Among samples of men and women, the lowest reported mean BMI was in South Asians (22.1 kg/m(2)), and the highest was in Filipinos (26.8 kg/m(2)). Estimates for overweight (12.8-46.7%) and obesity (2.1-59.0%) were variable. Among men and women, the highest rate of diabetes was reported in Asian Indians with BMI ≥ 30 kg/m(2) (32.9%, age and sex standardized). This review suggests heterogeneity among U.S. Asian populations in cardiometabolic risk factors, yet comparisons are limited due to variability in study populations, methods, and definitions used in published reports. Future efforts should adopt standardized methods to understand overweight, obesity and diabetes in this growing U.S. ethnic population.

Genetic loci for retinal arteriolar microcirculation

Narrow arterioles in the retina have been shown to predict hypertension as well as other vascular diseases, likely through an increase in the peripheral resistance of the microcirculatory flow. In this study, we performed a genome-wide association study in 18,722 unrelated individuals of European ancestry from the Cohorts for Heart and Aging Research in Genomic Epidemiology consortium and the Blue Mountain Eye Study, to identify genetic determinants associated with variations in retinal arteriolar caliber. Retinal vascular calibers were measured on digitized retinal photographs using a standardized protocol. One variant (rs2194025 on chromosome 5q14 near the myocyte enhancer factor 2C MEF2C gene) was associated with retinal arteriolar caliber in the meta-analysis of the discovery cohorts at genome-wide significance of P-value <5×10⁻⁸. This variant was replicated in an additional 3,939 individuals of European ancestry from the Australian Twins Study and Multi-Ethnic Study of Atherosclerosis (rs2194025, P-value = 2.11×10⁻¹² in combined meta-analysis of discovery and replication cohorts). In independent studies of modest sample sizes, no significant association was found between this variant and clinical outcomes including coronary artery disease, stroke, myocardial infarction or hypertension. In conclusion, we found one novel loci which underlie genetic variation in microvasculature which may be relevant to vascular disease. The relevance of these findings to clinical outcomes remains to be determined.

Prevalence and risk factors for age-related macular degeneration in Indians: a comparative study in Singapore and India

PURPOSE

To compare the prevalence and risk factors for age-related macular degeneration (AMD) in 2 Indian populations, 1 living in urban Singapore and 1 in rural central India.

DESIGN

Population-based, cross-sectional studies of Indians aged 40+ years.

METHODS

Our analysis included 3337 Singapore-residing participants and 3422 India-residing participants. All participants underwent comprehensive systemic and ocular examinations and retinal photography. AMD was graded from retinal photographs according to the Wisconsin Age-Related Maculopathy Grading System. Systemic and ocular risk factors were assessed for association with AMD.

RESULTS

Singapore-residing participants were older (mean age 57.8 years vs 53.8 years) and, after adjusting for age and sex, were more likely to have previous cataract surgery, higher body mass index, hypertension, diabetes, previous myocardial infarction, higher cholesterol, and lower creatinine levels, but less likely to be current smokers, than India-residing participants. The age-standardized prevalence of early and late AMD was 4.45% and 0.34%, respectively, in Singapore and 5.80% and 0.16%, respectively, in India. Shorter axial length was associated with early AMD in both Singapore and India, whereas previous cataract surgery, higher body mass index, hypertension, and lower cholesterol were associated with early AMD in Singapore but not in India.

CONCLUSION

The prevalence of AMD was similar among Indian adults living in urban Singapore and rural India, despite differences in cardiovascular risk factor profile and demographics.

Should Posterior Vitrectomy be Made a Priority in Ophthalmic Facilities of Sub Sahara Africa?

BACKGROUND

Posterior vitrectomy facilities are lacking in Sub Sahara Africa due to paucity of trained personnel in vitreo retinal subspecialty. More cases are seen needing vitrectomy, especially cases with vitreous opacities and complications of cataract surgery as more residents are being trained. The review will aim to determine whether vitrectomy facility should be a priority as part of ophthalmic facility in the region.

METHOD

A 3 year review was carried out. All cases of posterior vitrectomy performed at the retinal unit of the University College Hospital, Ibadan, Africa between 2008 and 20011 were retrieved. Indications, and visual outcome were documented. Proportions and percentages were used to analyse the data.

RESULTS

Sixty six posterior vitrectomies were performed during the period. The most common indication for vitrectomy was vitreous hemorrhage n=30 [45.5%].Complication of cataract surgery such as dropped intraocular lens 7 [10.7%], sclera fixated intra ocular lens 6 [9.2%], and dropped nucleus 5 [7.5%] were emerging indications. Other indications noted include complicated retinal detachments 4 (6.1%), membranectomy for posterior capsule opacity from pediatric cataract surgery 3 (4.5%) and congenital lens subluxation 2 (3.0%). Improved visual outcome was noted after surgery. Forty nine [75%] eyes were blind [visual acuity of < 3/60] before vitrectomy. This proportion dropped to 24 [37%] after vitrectomy with an additional 24% regaining navigational vision [visual acuity of 3/60 to Counting fingers at 1meter] .

CONCLUSION

Vitrectomy should be an integral part of eye care and its availability should be made a priority in ophthalmic facilities of Sub Sahara Africa, especially those involved in ophthalmology training.

Argon laser with and without anti-vascular endothelial growth factor therapy for extrafoveal polypoidal choroidal vasculopathy

PURPOSE

To describe the clinical characteristics and outcome of eyes with extrafoveal polypoidal choroidal vasculopathy (PCV) treated with argon laser.

DESIGN

Prospective cohort, noninterventional study.

METHODS

A prospective study of Asian patients with extrafoveal PCV, confirmed on indocyanine green angiography and treated with argon laser with and without anti-vascular endothelial growth factor (VEGF) therapy. Patients were followed-up over 12 months with visual, angiographic, and structural outcomes recorded.

RESULTS

Of the 93 eyes with PCV at baseline, 33 eyes (35.5%) in 31 patients had extrafoveal involvement and were treated with argon laser. Foveal involvement with fluid or blood at baseline was apparent in 23 eyes (69.7%), despite the extrafoveal location of 1 or more polyps. Of these 33 eyes, 12 (36.4%) also received anti-VEGF injections (median, 2.5 injections) over the 12-month period. Two eyes received photodynamic therapy rescue during subsequent follow-up and were excluded for visual outcome analysis. In the remaining 31 eyes, mean visual acuity improved from 0.57 logarithm of the minimal angle of resolution (logMAR) units (range, 0.00 to 2.0 logMAR; standard deviation, 0.51 logMAR) at baseline to 0.39 logMAR (range, 0.00 to 2.0 logMAR; standard deviation, 0.43 logMAR) at month 12 (P = .01), with a mean gain in visual acuity of 9.0 letters at month 12. Stable or improved vision (defined as losing 5 letters or fewer) was achieved in 28 eyes (90.3%). Use of anti-VEGF was associated with significantly thicker central subfield at baseline (347.6 vs 258.1 μm; P = .02) and resulted in similar vision and OCT results at month 3 and 12 compared with eyes that did not receive anti-VEGF.

CONCLUSIONS

Argon laser treatment with selected use of anti-VEGF therapy achieves stable or improved visual outcome in most eyes with extrafoveal PCV, including eyes with fluid or blood affecting the fovea at presentation.

Association between polymorphisms of complement pathway genes and age-related macular degeneration in a Chinese population

PURPOSE

We assessed the association between complement pathway genes and age-related macular degeneration (AMD) in a Chinese population.

METHODS

In a case-control study, 165 AMD patients and 216 unrelated controls were recruited from two hospitals in central China. We selected and genotyped six single nucleotide polymorphisms (SNPs) of four complement pathway genes, including rs800292 and rs1410996 of complement H (CFH), rs9332739 of complement 2 (C2), rs4151667 of complement factor B (CFB), and rs2241394 and rs2230199 of complement 3 (C3). The associations between SNPs and AMD, adjusted by age and sex, were assessed by using logistic regression models and haplotype association analysis.

RESULTS

In our study, two SNPs of CFH and their haplotypes were associated significantly with AMD, and the adjusted odd ratios (ORs) were 2.45 (95% confidence interval [CI] 1.25-4.79) for rs800292 (genotype GG versus AA), 2.49 (95% CI 1.24-5.00) for rs1410996 (genotype TT versus CC), and 4.45 (95% CI 2.32-8.55) for haplotype block of rs800292-rs1410996 (haplotype G-C versus A-C), respectively. The haplotype of C2/CFB also was associated significantly with AMD, and the adjusted OR was 8.86 (95% CI 1.88-41.69) for the haplotype block of rs9332739-rs4151667 (haplotype G-A versus G-T), though no relationship was found in genotype association analysis of the two SNPs of C2/CFB. With the sample size of our study, no relationship was found for AMD and the two SNPs of C3.

CONCLUSIONS

Gene variants in CFH and C2/CFB contribute to AMD in the Chinese population.

Genetic studies of age-related macular degeneration: lessons, challenges, and opportunities for disease management

BACKGROUND

Age-related macular degeneration (AMD) is a common cause of visual impairment in individuals >55 years of age worldwide. The varying clinical phenotypes of AMD result from contributions of genetic, epigenetic, and nongenetic (environmental) factors. Genetic studies of AMD have come of age as a direct result of tremendous gains from the human genome project, genome-wide association studies, and identification of numerous susceptibility loci. These findings have implicated immune response, high-density lipoprotein cholesterol metabolism, extracellular matrix, and angiogenesis signaling pathways in disease pathophysiology.

MAIN OUTCOME MEASURES

Herein, we address how the wealth of genetic findings in AMD is expected to impact the practice of medicine, providing opportunities for improved risk assessment, molecular diagnosis, preventive, and therapeutic intervention.

CONCLUSIONS

We propose that the potential of using genetic variants for monitoring treatment response (pharmacogenetics) may usher in a new era of personalized medicine in the clinical management of AMD.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosures may be found after the references.

Prospective study of particulate air pollution exposures, subclinical atherosclerosis, and clinical cardiovascular disease: The Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air)

The Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air) was initiated in 2004 to investigate the relation between individual-level estimates of long-term air pollution exposure and the progression of subclinical atherosclerosis and the incidence of cardiovascular disease (CVD). MESA Air builds on a multicenter, community-based US study of CVD, supplementing that study with additional participants, outcome measurements, and state-of-the-art air pollution exposure assessments of fine particulate matter, oxides of nitrogen, and black carbon. More than 7,000 participants aged 45-84 years are being followed for over 10 years for the identification and characterization of CVD events, including acute myocardial infarction and other coronary artery disease, stroke, peripheral artery disease, and congestive heart failure; cardiac procedures; and mortality. Subcohorts undergo baseline and follow-up measurements of coronary artery calcium using computed tomography and carotid artery intima-medial wall thickness using ultrasonography. This cohort provides vast exposure heterogeneity in ranges currently experienced and permitted in most developed nations, and the air monitoring and modeling methods employed will provide individual estimates of exposure that incorporate residence-specific infiltration characteristics and participant-specific time-activity patterns. The overarching study aim is to understand and reduce uncertainty in health effect estimation regarding long-term exposure to air pollution and CVD.

Genetics of immunological and inflammatory components in age-related macular degeneration

Age-related macular degeneration (AMD), affecting 30 to 50 million elder individuals worldwide, is a disease affecting the macular retina and choroid that can lead to irreversible central vision loss and blindness. Recent findings support a role for immunologic processes in AMD pathogenesis, including generation of inflammatory related molecules in the Bruch's membrane, recruitment of macrophages, complement activation, microglial activation and accumulation in the macular lesions. Pro-inflammatory effects of chronic inflammation and oxidative stress can result in abnormal retinal pigment epithelium, photoreceptor atrophy and choroidal neovascularization. The associations of immunological and inflammatory genes, in particular the genes related to innate immunity with AMD support the involvement of various immunological pathways in the AMD pathogenesis. We review the literature on the involvements of inflammatory genes in AMD, highlight recent genetic discoveries, and discuss the potential application of such knowledge in the management of patients with AMD.

Bevacizumab and ranibizumab for neovascular age-related macular degeneration: a treatment approach based on individual patient needs

OBJECTIVE

To compare the efficacy of intravitreal bevacizumab and ranibizumab for the treatment of neovascular age-related macular degeneration using an as-needed treatment regimen.

DESIGN

Retrospective chart review.

PARTICIPANTS

One hundred and ninety two eyes of 184 patients.

METHODS

Patients received an initial treatment of 3 monthly intravitreal injections of ranibizumab or bevacizumab and retreatment is individually considered for each patient on the basis of optical coherence tomography, angiography, and clinical examination.

RESULTS

Fifty eyes treated with ranibizumab and 142 eyes treated with bevacizumab were included. The average age of the patients at baseline was 76.9 ± 8 years and 76.4 ± 8 years in the ranibizumab and bevacizumab group respectively. Mean visual acuity improved from 0.69 to 0.55 logMAR at 12 months in the ranibizumab group and from 0.70 to 0.67 logMAR in the bevacizumab group. At 12 months, 92% of eyes treated with ranibizumab had lost fewer than 0.3 logMAR, as compared with 83% in the bevacizumab group. The ranibizumab group received a mean of 4.92 injections, compared to 4.75 injections in the bevacizumab group over 12 months. After the first 3 injections, 20% of patients in the ranibizumab group and 26% in the bevacizumab group never needed another injection.

CONCLUSIONS

An approach based on clinical onset and choroidal neovascularization progression at angiography may provide benefit by reducing the number of intravitreal injections required.

Is age-related macular degeneration a problem in Ibadan, Sub-Saharan Africa?

Background

Age-related macular degeneration (AMD) is considered uncommon in black populations including those of Sub-Saharan Africa. The aim of this review was to determine the pattern of presentation of AMD in our hospital located in Ibadan, the largest city in Sub-Saharan Africa.

Methods

A retrospective review of all cases with AMD presenting to the Eye and Retinal Clinic of the University College Hospital, Ibadan, West Africa was undertaken between October 2007 and September 2010.

Results

In the 3 years reviewed, 768 retinal cases were seen in the hospital, 101 (14%) of which were diagnosed with AMD. The peak age was 60–79 years. The male to female ratio was approximately 2:3. More males presented with the advanced form of dry AMD than females (odds ratio = 2.33). However, more females had advanced wet AMD than males (odds ratio = 1.85). Wet AMD was seen in 40 cases (40%).

Conclusion

The review determined that, as AMD is not uncommon and wet AMD is relatively more common in our hospital than has been reported previously, this is probably true of Ibadan in general.

Asian age-related macular degeneration phenotyping study: rationale, design and protocol of a prospective cohort study

BACKGROUND

  Current knowledge of the phenotypic characteristics (e.g. clinical features, risk factors, natural history and treatment response) of age-related macular degeneration (AMD) in Asians remains limited. This report summarizes the rationale and study design of a prospective observational study of Asian neovascular AMD, including polypoidal choroidovasculopathy variant.

DESIGN

  The Asian AMD phenotyping study is a prospective, observational clinical study of Asian patients with neovascular AMD or polypoidal choroidovasculopathy in three tertiary eye centres in Singapore.

PARTICIPANTS

  The study aims to recruit 500 consecutive patients from the retinal clinics of three tertiary eye centres in Singapore.

METHODS

  Standardized examination procedures include interviews, a comprehensive eye examination, digital photography of the retina, fundus fluorescein and indocyanine green angiography and spectral domain optical coherence tomography using a standardized protocol. Blood samples were collected for biochemical analyses and stored for genetic and proteomic studies.

MAIN OUTCOME MEASURES

  The aim of the study was to build a comprehensive database of clinical, angiographic, functional and natural history data of Asian AMD over a 12-month follow-up period.

RESULTS

  This article discusses the methodology and design of this prospective multi-centred study.

CONCLUSION

  This study will provide in-depth longitudinal data of the evolution of clinical features, risk factors, natural history and treatment pattern and response of Asian AMD and polypoidal choroidovasculopathy, allowing unique insights into pathogenesis and the design of new treatment strategies.

Nutritional modulation of age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly worldwide. It affects 30-50 million individuals and clinical hallmarks of AMD are observed in at least one third of persons over the age of 75 in industrialized countries (Gehrs et al., 2006). Costs associated with AMD are in excess of $340 billion US (American-Health-Assistance-Foundation, 2012). The majority of AMD patients in the United States are not eligible for clinical treatments (Biarnes et al., 2011; Klein et al., 2011). Preventive interventions through dietary modulation are attractive strategies because many studies suggest a benefit of micro- and macronutrients with respect to AMD, as well as other age-related debilities, and with few, if any, adverse effects (Chiu, 2011). Preservation of vision would enhance quality of life for millions of elderly people, and alleviate the personal and public health financial burden of AMD (Frick et al., 2007; Wood et al., 2011). Observational studies indicate that maintaining adequate levels of omega-3 fatty acids (i.e. with 2 servings/week of fish) or a low glycemic index diet may be particularly beneficial for early AMD and that higher levels of carotenoids may be protective, most probably, against neovascular AMD. Intervention trials are needed to better understand the full effect of these nutrients and/or combinations of nutrients on retinal health. Analyses that describe effects of a nutrient on onset and/or progress of AMD are valuable because they indicate the value of a nutrient to arrest AMD at the early stages. This comprehensive summary provides essential information about the value of nutrients with regard to diminishing risk for onset or progress of AMD and can serve as a guide until data from ongoing intervention trials are available.

Age-related macular degeneration and incident cardiovascular disease: the Multi-Ethnic Study of Atherosclerosis

OBJECTIVE

To determine whether age-related macular degeneration (AMD) is a risk indicator for coronary heart disease (CHD) and cardiovascular disease (CVD) events independent of other known risk factors in a multi-ethnic cohort.

DESIGN

Population-based prospective cohort study.

PARTICIPANTS

A diverse population sample of 6233 men and women aged 45 to 84 years without known CVD from the Multi-Ethnic Study of Atherosclerosis (MESA).

METHODS

Participants in the MESA had retinal photographs taken between 2002 and 2003. Photographs were evaluated for AMD. Incident CHD and CVD events were ascertained during clinical follow-up visits for up to 8 years after the retinal images were taken.

MAIN OUTCOME MEASURES

Incident CHD and CVD events.

RESULTS

Of the 6814 persons at risk of CHD, there were 893 participants with early AMD (13.1%) and 27 patients (0.5%) at baseline. Over a mean follow-up period of 5.4 years, there was no statistically significant difference in incident CHD or CVD between the AMD and non-AMD groups (5.0% vs. 3.9%, P = 0.13 for CHD and 6.6% vs. 5.5%, P = 0.19 for CVD). In Cox regression models adjusting for CVD risk factors, there was no significant relationship between presence of any AMD and any CHD/CVD events (hazard ratio 0.99; 95% confidence interval, 0.74-1.33; P = 0.97). No significant association was found between subgroups of early AMD or late AMD and incident CHD/CVD events.

CONCLUSIONS

In persons without a history of CVD, AMD was not associated with an increased risk of CHD or CVD.

Changes in blood oxidative and antioxidant parameters in a group of Chinese patients with age-related macular degeneration

OBJECTIVE

To measure the oxidative and antioxidant biochemical parameters in the serum of Chinese patients with age-related macular degeneration (AMD) and in a similar age control group from the same area.

DESIGN

A case-control study.

PARTICIPANTS

56 AMD patients ( 21 early dry, 13 geographic atrophy and 22 wet form) and 34 normal subjects, similar for age and sex were studied.

MEASUREMENTS

Both groups completed a questionnaire about demographic characters and dieatry habit, and the levels of serum lipid peroxidation (malondialdehyde, MDA) and antioxidants parameters (vitamin C and E, the activities of superoxide dismutase--SOD, total antioxidant capacity--TAC ) were determined.

RESULTS

There was a significantly higher frequency of daily intake of fruit and legumes in controls than in AMD patients. There was a significantly increased serum MDA levels and SOD activities, and significantly decreased serum vitamin C and total antioxidant capacity in AMD patients as compared to controls. The intensity of lipid peroxidation was higher with the progression of AMD. There was not difference in serum vitamin E levels between AMD patients and controls.

CONCLUSION

Oxido-reduction disturbance may be involved in the pathogenesis of AMD. There is a significantly decreased antioxidant capacity in AMD patients.

Intravitreal bevacizumab alone versus in combination with photodynamic therapy for the treatment of neovascular maculopathy in patients aged 50 years or older: 1-year results of a prospective clinical study

PURPOSE

To compare the outcomes of treatment with intravitreal bevacizumab alone (BEVA group) or in combination with photodynamic therapy (PDT) (COMB group), in patients aged at least 50 years with neovascular maculopathy.

METHODS

Forty-one patients with neovascular age-related macular degeneration (AMD) (n = 31) or polypoidal choroidal vasculopathy (PCV) (n = 10) were randomized to either the BEVA group (n = 18) or the COMB group (n = 23). A total of three intravitreal bevacizumab injections (1.25 mg/0.05 ml) were given at 6-week intervals. In the COMB group, PDT was included near the time of one injection. Patients underwent best-corrected visual acuity (BCVA) measurement and optical coherence tomography (OCT) at every visit. Fluorescein angiography and indocyanine green angiography were repeated every 3 months.

RESULTS

Overall BCVA (p = 0.001) and central foveal thickness (CFT) (p < 0.001) measured by OCT improved significantly at 12 months, and there was no between-group difference in BCVA or CFT between the BEVA and COMB groups. Whereas AMD patients showed significant improvement in BCVA (p = 0.001) and CFT (p = 0.004), PCV patients failed to improve. The effect of bevacizumab alone on neovascular AMD was similar to that of combination therapy, when measured by both BCVA and CFT. The total number of bevacizumab injections was not reduced when PDT was given, either among all patients or in a subgroup of naïve patients (p > 0.05). No serious complication was noted.

CONCLUSION

The results of our 12-month prospective study indicate that intravitreal bevacizumab alone has similar efficacy and safety to bevacizumab plus PDT for treatment of patients with neovascular AMD, even treatment-naïve patients. The addition of PDT did not assist in reducing the required total number of bevacizumab injections.

Causes of blindness and visual impairment in Latin America

We review what is known in each country of the Latin American region with regards to blindness and visual impairment and make some comparisons to Hispanic populations in the United States. Prevalence of blindness varied from 1.1% in Argentina to 4.1% in Guatemala in people 50 years of age and older, with the major cause being cataract. Diabetic retinopathy and glaucoma are starting to make serious inroads, although epidemiological data are limited, and age-related macular degeneration is now a concern in some populations. Infectious diseases such as trachoma and onchocerciasis are quickly diminishing. Although progress has been made, retinopathy of prematurity remains the major cause of childhood blindness. If VISION 2020 is to succeed, many more epidemiological studies will be needed to set priorities, although some can be of the Rapid Assessment of Avoidable Blindness design. Developing the infrastructure for screening and treatment of ophthalmic disease in Latin America continues to be a challenge.

Rates of nonexudative and exudative age-related macular degeneration among Asian American ethnic groups

PURPOSE

To determine whether the risk for nonexudative and exudative age-related macular degeneration (AMD) varies for Americans of different Asian ethnicities.

METHODS

Claims data from a large national United States managed care network were reviewed to identify Asian Americans age 40 and older who had ≥ 1 eye care visits from 2001 to 2007. International Classification of Disease (ICD-9CM) billing codes were used to identify enrollees with nonexudative and exudative AMD. Incidence and prevalence rates were calculated for nonexudative and exudative AMD and were stratified by Asian ethnicity. Cox regression analyses were performed to determine the relative risk for developing nonexudative and exudative AMD for persons of different Asian ethnicities, with adjustment for sociodemographic factors and ocular and medical conditions.

RESULTS

Of the 44,103 Asian Americans who met the inclusion criteria, 2221 (5.04%) had nonexudative AMD and 217 (0.49%) had exudative AMD. Chinese Americans (adjusted hazard ratio [HR], 1.63; 95% confidence interval [CI], 1.50-1.77) and Pakistani Americans (HR, 1.97, 95% CI, 1.40-2.77) had a significantly increased risk for nonexudative AMD compared with non-Hispanic white Americans. By contrast, Japanese Americans had a 29% decreased risk for nonexudative AMD compared with non-Hispanic white Americans (HR, 0.71; 95% CI, 0.59-0.85). There were no significant differences in risk for exudative AMD for any of the Asian ethnicities compared with white Americans.

CONCLUSIONS

Asian Americans are the second fastest growing racial group in the United States. Eye care providers must be aware of the overall disease burden of AMD within this group and appreciate how disease rates can vary substantially among different Asian ethnicities.

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.

Racial differences in age-related macular degeneration rates in the United States: a longitudinal analysis of a managed care network

PURPOSE

To compare the incidence, prevalence, and hazard of nonexudative and exudative age-related macular degeneration (AMD) among different races throughout the United States.

DESIGN

Retrospective longitudinal cohort study.

METHODS

Billing records of all encounters for 2 259 061 beneficiaries aged ≥40 enrolled in a large, national US managed care network from 2001 through 2007 were reviewed and the incidence and prevalence of nonexudative and exudative AMD were determined and stratified by race. Cox regression analyses determined the hazard of nonexudative and exudative AMD for each race, with adjustment for confounders.

RESULTS

During the study, 113 234 individuals (5.0%) were diagnosed with nonexudative and 17 181 (0.76%) with exudative AMD. After adjustment for confounders, blacks had a significantly reduced hazard of nonexudative (hazard ratio [HR]=0.75, 95% confidence interval [CI]: 0.71-0.79) and exudative AMD (HR=0.70, 95% CI: 0.59-0.83) at age 60 and a reduced hazard of nonexudative (HR=0.56, 95% CI: 0.52-0.60) and exudative AMD (HR=0.45, 95% CI: 0.37-0.54) at age 80 relative to whites. Similar comparisons for Latinos demonstrated an 18% reduced hazard for nonexudative AMD at age 80 (HR=0.82, 95% CI: 0.76-0.88) relative to whites. Asian Americans showed a 28% increased hazard for nonexudative AMD at age 60 (HR=1.28, 95% CI: 1.20-1.36) but a 46% decreased hazard for exudative AMD at age 80 (HR=0.54, 95% CI: 0.40-0.73).

CONCLUSIONS

Racial minorities, including Latinos and Asian Americans, do not appear to have similar risks of developing nonexudative and exudative AMD as whites. Additional studies using other sources should be conducted to determine the generalizability of this study's findings to other groups.

Current and emerging therapies for the treatment of age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of vision loss in the industrialized world. In the last few decades, the mainstay of treatment for choroidal neovascularization (CNV) due to AMD has been thermal laser photocoagulation. In the last decade, photodynamic therapy with verteporfin extended treatment for more patients. While both of these treatments have prevented further vision loss in a subset of patients, improvement in visual acuity is rare. Anti-vascular endothelial growth factor A (VEGF) therapy has revolutionized the treatment of AMD-related CNV. Pegaptanib, an anti-VEGF aptamer prevents vision loss in CNV, although the performance is similar to that of photodynamic therapy. Ranibizumab, an antibody fragment and bevacizumab, a full-length humanized monoclonal antibody against VEGF have both shown promising results with improvements in visual acuity with either agent. VEGF trap, a modified soluble VEGF receptor analogue, binds VEGF more tightly than all other anti-VEGF agents and has also shown promising results in early trials. Other treatment strategies to decrease the effect of VEGF have used small interfering ribonucleic acid (RNA) to inhibit VEGF production and VEGF receptor production. Steroids, including anecortave acetate in the treatment and prevention of CNV, have shown promise in controlled trials. Receptor tyrosine kinase inhibitors, such as vatalanib, inhibit downstream effects of VEGF, and have been effective in the treatment of CNV in early studies. Squalamine lactate inhibits plasma membrane ion channels with downstream effects on VEGF, and has shown promising results with systemic administration. Other growth factors, including pigment epithelium-derived growth factor that has been administered via an adenoviral vector has shown promising initial results. In some patients ciliary neurotrophic factor is currently being studied for the inhibition of progression of geographic atrophy. Combination therapy has been investigated, and may prove to be more effective in the management of AMD-associated CNV. Ongoing and future studies will be crucial for optimizing the treatment of patients with AMD.

Retinopathy signs in people without diabetes: the multi-ethnic study of atherosclerosis

OBJECTIVE

To describe the prevalence of retinopathy and associations with cardiovascular risk factors in persons without diabetes in 4 racial/ethnic groups (white, black, Hispanic, and Chinese).

DESIGN

Population-based, cross-sectional study.

PARTICIPANTS

We included 6176 subjects aged 45-84 years without diabetes, selected from 6 United States communities.

METHODS

Fundus images were taken using 45° digital camera through dark-adapted pupils and were graded for retinopathy as defined by the Early Treatment Diabetic Retinopathy Study severity scale: microaneurysms, hemorrhages, cotton wool spots, intraretinal microvascular abnormalities, hard exudates, venous beading, and new vessels.

MAIN OUTCOME MEASURES

Retinopathy and the association with cardiovascular risk factors.

RESULTS

Prevalence rates of retinopathy in persons without diabetes were 12.5% overall, varying from 11.9% (white), 13.9% (black), 12.6% (Hispanic), to 17.2% (Chinese). Hypertension was strongly associated with retinopathy (odds ratio [OR], 1.47; 95% confidence interval [CI], 1.23-1.75). After adjusting for age, gender, race, and other parameters, smoking (OR, 1.50; 95% CI, 1.09-2.06) and increased internal carotid intima media thickness (OR, 1.22; 95% CI, 1.05-1.41) were associated with retinopathy. A range of serum inflammatory factors were examined, but none were found to be significant.

CONCLUSIONS

Retinopathy in persons without diabetes is common, varies with race/ethnicity, and associated with cardiovascular risk factors, including hypertension, smoking, and carotid artery intima media thickness.

Prevalence of age-related macular degeneration in a rural Chinese population: the Handan Eye Study

PURPOSE

To describe the prevalence of age-related degeneration (AMD) in a rural Chinese population and to assess its associations with age, gender, and smoking.

DESIGN

Population-based cross-sectional.

PARTICIPANTS

Persons aged 30+ years, recruited between October 2006 and October 2007, from Yongnian County, Handan, Hebei Province, China.

METHODS

All participants underwent a standardized interview and comprehensive eye examinations, including digital retinal photography of both eyes. Trained graders assessed the presence and severity of AMD lesions following the modified Wisconsin Age-related Maculopathy Grading System (WARMGS) used in the Blue Mountains Eye Study (BMES). Direct age standardization to the world population (year 2000) was performed to compare the prevalence across different populations.

MAIN OUTCOME MEASURES

AMD and WARMGS.

RESULTS

Of 6830 participates, fundus photographs were gradable for 6581 persons (96.4%), including 4049 aged 50+ years. Early and late AMD prevalence rates were 3.0% and 0.1%, respectively, among participants. The age-standardized prevalence rates among participants aged 50+ years were 4.7% and 0.2%, respectively. After controlling for age, men had a higher prevalence of early (3.9% vs. 2.3%, odds ratio [OR] 1.7; 95% confidence interval [CI], 1.3-2.2) and late AMD (0.1% vs. 0.03%; OR 3.5; CI, 0.4-33.4) compared with women. Older age (sex-adjusted OR 1.7; CI, 1.3-2.2 per decade of age) and current smoking (age-sex-adjusted OR 1.4; CI, 1.0-2.1) were significantly associated with early AMD prevalence. The proportion of current smokers was substantially higher in men (58.7%) than in women (0.3%). The attributable risk of early AMD from smoking among Chinese men was 24.2%. After controlling for current smoking, the excess prevalence of early AMD in men compared with women reduced by 50% (OR 1.4; 95% CI, 0.9-2.0).

CONCLUSIONS

The prevalence of early AMD in this rural Chinese sample was similar to white persons in the BMES and Asian Malays in the Singapore Malay Eye Study. Late AMD prevalence, however, was lower. Higher prevalence rates for early and late AMD in men compared with women were largely attributed to substantially higher proportions of smokers in rural Chinese men than in women.

Impact of AREDS in a developing country 5 years after publication of the study

PURPOSE

The Age-Related Eye Disease Study (AREDS) is the only large-scale study to demonstrate a reduction in the risk of progression to end-stage age-related macular degeneration (AMD) when vitamin supplementation was given to patients with advanced forms of the disease. Our study assesses the impact of this study on vitamin supplementation in patients with advanced AMD from 5 years before publication of the AREDS results until 5 years after.

METHODS

Medical records of patients with AMD presenting between September 1996 and October 2006 were reviewed. Patients were subclassified according to AREDS categories. The proportion of advanced cases on vitamin replacement before October 2001 was compared to that after October 2001. Since October 2001, the different reasons for abstinence were investigated and analyzed.

RESULTS

Only 2403 patients of the 40,000 medical records reviewed met the AREDS AMD criteria. Of these, 137 patients verifying categories 3 and 4 were diagnosed prior to October 2001. Fourteen were on supplements then. Fifty-three patients complied with the represcribed vitamins during subsequent visits after October 2001, raising the percentage significantly to 48.9% (p<0.001). Also, from October 2001 until October 2006, an additional 76 patients verified categories 3 and 4. Fifty-three (69.7%) of them were on vitamins (p=0.001). Financial burden was the principal reason for abstinence in 67.7% of patients prescribed vitamins after October 2001.

CONCLUSIONS

The results of AREDS had an impressive impact on prescribing supplements in AREDS category 3 and 4 patients in Lebanon. The main reason for noncompliance is financial.

Complement in age-related macular degeneration: a focus on function

Age-related macular degeneration (AMD) is an inflammatory disease, which causes visual impairment and blindness in older people. The proteins of the complement system are central to the development of this disease. Local and systemic inflammation in AMD are mediated by the deregulated action of the alternative pathway of the complement system. Variants in complement system genes alter an individual's risk of developing AMD. Recent studies have shown how some risk-associated genetic variants alter the function of the complement system. In this review, we describe the evolution of the complement system and bring together recent research to form a picture of how changes in complement system genes and proteins affect the function of the complement cascade, and how this affects the development of AMD. We discuss the application of this knowledge to prevention and possible future treatments of AMD.

Retinal arteriolar caliber and urine albumin excretion: the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Changes in retinal microvascular caliber, which occur prior to onset of retinopathy, may indicate presence of kidney damage.

METHODS

This study examined the association between retinal arteriolar [central retinal artery equivalent (CRAE)] and venular caliber [central retinal venule equivalent (CRVE)] and presence of albuminuria (micro- or macroalbuminuria) among participants of the Multi-Ethnic Study of Atherosclerosis (MESA), a cohort of adults aged 45-84 years without baseline clinical cardiovascular disease. During the second MESA exam, digital fundus photography was completed in 5897 participants who provided spot urine specimens. Albuminuria was defined by spot urine albumin/creatinine ratios ≥ 30 mg/g. Multivariable adjusted odds of albuminuria by quintiles of CRAE and CRVE were determined using logistic regression. Analyses were repeated after stratifying by presence of type 2 diabetes.

RESULTS

Albuminuria was noted in 11.5% (n = 675) and included 584 subjects with microalbuminuria and 91 with macroalbuminuria. A significant U-shaped pattern was seen with higher prevalence of albuminuria across quintile extremes in CRAE (15.7, 8.8 and 10.6% in CRAE Quintiles 1, 3 and 5, respectively; P <0.0001). After adjustment for covariates, both narrower CRAE [odds ratios (OR) 1.55; 95% confidence interval (CI) 1.17-2.04, Quintile 1 versus 3) and wider CRAE (OR 1.44; 95% CI 1.07-1.93, Quintile 5 versus 3) were significantly associated with albuminuria. Associations appeared substantially stronger in adults with than without type 2 diabetes but the interaction term for diabetes and CRAE on presence of albuminuria did not meet statistical significance (P = 0.3). No association was noted between CRVE quintiles and albuminuria.

CONCLUSIONS

Albuminuria is associated with narrower and wider arteriolar caliber. Future studies should determine whether variation in arteriolar caliber predicts incident albuminuria and whether associations are mediated by hypertension and diabetes. Such information could further clarify early microvascular processes in the pathogenesis of kidney disease.

Cell-deposited matrix improves retinal pigment epithelium survival on aged submacular human Bruch's membrane

PURPOSE

To determine whether resurfacing submacular human Bruch's membrane with a cell-deposited extracellular matrix (ECM) improves retinal pigment epithelial (RPE) survival.

METHODS

Bovine corneal endothelial (BCE) cells were seeded onto the inner collagenous layer of submacular Bruch's membrane explants of human donor eyes to allow ECM deposition. Control explants from fellow eyes were cultured in medium only. The deposited ECM was exposed by removing BCE. Fetal RPE cells were then cultured on these explants for 1, 14, or 21 days. The explants were analyzed quantitatively by light microscopy and scanning electron microscopy. Surviving RPE cells from explants cultured for 21 days were harvested to compare bestrophin and RPE65 mRNA expression. Mass spectroscopy was performed on BCE-ECM to examine the protein composition.

RESULTS

The BCE-treated explants showed significantly higher RPE nuclear density than did the control explants at all time points. RPE expressed more differentiated features on BCE-treated explants than on untreated explants, but expressed very little mRNA for bestrophin or RPE65. The untreated young (<50 years) and African American submacular Bruch's membrane explants supported significantly higher RPE nuclear densities (NDs) than did the Caucasian explants. These differences were reduced or nonexistent in the BCE-ECM-treated explants. Proteins identified in the BCE-ECM included ECM proteins, ECM-associated proteins, cell membrane proteins, and intracellular proteins.

CONCLUSIONS

Increased RPE survival can be achieved on aged submacular human Bruch's membrane by resurfacing the latter with a cell-deposited ECM. Caucasian eyes seem to benefit the most, as cell survival is the worst on submacular Bruch's membrane in these eyes.

Physical activity, television viewing time, and retinal microvascular caliber: the multi-ethnic study of atherosclerosis

Physical activities and sedentary behaviors are 2 broad classes of behavior that may be clearly distinguished from each other and have different patterns of determinants. The authors examined the associations of physical activity and television viewing time with retinal vascular caliber among US adults (n = 5,893) from 4 racial/ethnic groups in the Multi-Ethnic Study of Atherosclerosis (2002-2004) that included non-Hispanic whites, blacks, Hispanics, and Chinese. Physical activity and television viewing time were assessed by using a questionnaire, and vascular calibers (arteriolar and venular) were measured from digital retinal photographs. Those in the lowest quartile of physical activity had wider retinal venular caliber compared with those in the highest quartile in multivariate models adjusted for demographic, cardiovascular, behavioral, and inflammatory risk factors. This was noted in non-Hispanic whites and Hispanics but not in blacks or Chinese. For television viewing time, non-Hispanic whites (but not the other racial/ethnic groups) who were in the highest quartile of television viewing time had wider retinal venular caliber compared with those in the lowest quartile. No associations were noted with arteriolar caliber. Lower levels of physical activity (among non-Hispanic whites and Hispanics) and higher levels of television viewing time (among whites) are associated with wider retinal venules.

Age-related macular degeneration: genetic and environmental factors of disease

Age-related macular degeneration (AMD) is the most common cause of visual impairment among the elderly in developed countries, and its prevalence is thus increasing as the population ages; however, treatment options remain limited because the etiology and pathogenesis of AMD are incompletely defined. Recently, much progress has been made in gene discovery and mechanistic studies, which clearly indicate that AMD involves the interaction of multiple genetic and environmental factors. The identification of genes that have a substantial impact on the risk for AMD is not only facilitating the diagnosis and screening of populations at risk but is also elucidating key molecular pathways of pathogenesis. Pharmacogenetic studies of treatment responsiveness among patients with the "wet" form of AMD are increasingly proving to be clinically relevant; pharmacogenetic approaches hold great promise for both identifying patients with the best chance for vision recovery as well as tailoring individualized therapies.

Race- and sex-related differences in retinal thickness and foveal pit morphology

PURPOSE

To examine sex- and race-associated differences in macular thickness and foveal pit morphology by using spectral-domain optical coherence tomography (SD-OCT).

METHODS

One hundred eighty eyes of 90 healthy patients (43 women, 47 men) underwent retinal imaging with spectral-domain OCT. The lateral scale of each macular volume scan was corrected for individual differences in axial length by ocular biometry. From these corrected volumes, Early Treatment Diabetic Retinopathy Study (ETDRS) grids of retinal thickness were generated and compared between the groups. Foveal morphology was measured with previously described algorithms.

RESULTS

Compared with the Caucasians, the Africans and African Americans had reduced central subfield thickness. Central subfield thickness was also reduced in the women compared with the men, although the women also showed significant thinning in parafoveal regions. There was no difference between the sexes in foveal pit morphology; however, the Africans/African Americans had significantly deeper and broader foveal pits than the Caucasians.

CONCLUSIONS

Previous studies have reported race- and sex-associated differences in macular thickness, and the inference has been that these differences represent similar anatomic features. However, the data on pit morphology collected in the present study reveal an important and significant variation. Between the sexes, the differences are due to global variability in retinal thickness, whereas the variation in thickness observed between the races appears to be driven by differences in foveal pit morphology. These differences have important implications for the use of SD-OCT in detecting and diagnosing retinal disease.

Clinical risk factors for age-related macular degeneration: a systematic review and meta-analysis

BACKGROUND

Age-related macular degeneration (AMD) is the leading cause of blindness in Western countries. Numerous risk factors have been reported but the evidence and strength of association is variable. We aimed to identify those risk factors with strong levels of evidence which could be easily assessed by physicians or ophthalmologists to implement preventive interventions or address current behaviours.

METHODS

A systematic review identified 18 prospective and cross-sectional studies and 6 case control studies involving 113,780 persons with 17,236 cases of late AMD that included an estimate of the association between late AMD and at least one of 16 pre-selected risk factors. Fixed-effects meta-analyses were conducted for each factor to combine odds ratio (OR) and/or relative risk (RR) outcomes across studies by study design. Overall raw point estimates of each risk factor and associated 95% confidence intervals (CI) were calculated.

RESULTS

Increasing age, current cigarette smoking, previous cataract surgery, and a family history of AMD showed strong and consistent associations with late AMD. Risk factors with moderate and consistent associations were higher body mass index, history of cardiovascular disease, hypertension, and higher plasma fibrinogen. Risk factors with weaker and inconsistent associations were gender, ethnicity, diabetes, iris colour, history of cerebrovascular disease, and serum total and HDL cholesterol and triglyceride levels.

CONCLUSIONS

Smoking, previous cataract surgery and a family history of AMD are consistent risk factors for AMD. Cardiovascular risk factors are also associated with AMD. Knowledge of these risk factors that may be easily assessed by physicians and general ophthalmologists may assist in identification and appropriate referral of persons at risk of AMD.

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

PURPOSE

To describe the prevalence and signs of early and late age-related macular degeneration (AMD) in an old cohort.

DESIGN

Population-based cohort study.

PARTICIPANTS

We included 5272 persons aged ≥66 years, randomly sampled from the Reykjavik area.

METHODS

Fundus images were taken through dilated pupils using a 45-degree digital camera and graded for drusen size, type, area, increased retinal pigment, retinal pigment epithelial depigmentation, neovascular lesions, and geographic atrophy (GA) using the modified Wisconsin Age-Related Maculopathy Grading System.

MAIN OUTCOME MEASURES

Age-related macular degeneration in an elderly cohort.

RESULTS

The mean age of participants was 76 years. The prevalence of early AMD was 12.4% (95% confidence interval [CI], 11.0-13.9) for those aged 66 to 74 years and 36% (95% CI, 30.9-41.1) for those aged ≥85 years. The prevalence of exudative AMD was 3.3% (95% CI, 2.8-3.8). The prevalence of pure GA was 2.4% (95% CI, 2.0-2.8). The highest prevalence of late AMD was among those aged ≥85 years: 11.4% (95% CI, 8.2-14.5) for exudative AMD and 7.6% (95% CI, 4.8-10.4) for pure GA.

CONCLUSIONS

Persons aged ≥85 years have a 10-fold higher prevalence of late AMD than those aged 70 to 74 years. The high prevalence of late AMD in the oldest age group and expected increase of elderly people in the western world in coming years call for improved preventive measures and novel treatments.

Nutrition and age-related eye diseases: the Alienor (Antioxydants, Lipides Essentiels, Nutrition et maladies OculaiRes) Study

BACKGROUND

Worldwide, degenerative eye diseases (age-related maculopathy (ARM), cataract, glaucoma) are the main causes of visual impairment and blindness, which contribute to disability in the elderly. Mainly three types of nutritional factors are investigated for their potential protection against eye ageing: antioxidants; lutein and zeaxanthin (carotenoids which accumulate specifically in the eye); omega 3 polyunsaturated fatty acids. Few epidemiological studies have been conducted in this field, particularly in Europe.

OBJECTIVE

The Alienor (Antioxydants, Lipides Essentiels, Nutrition et maladies OculaiRes) Study aims at assessing the associations of eye diseases with nutritional factors, determined from plasma measurements and estimation of dietary intakes.

DESIGN, SETTING AND PARTICIPANTS

Subjects were recruited in Bordeaux (France) from the ongoing population-based 3C study. In 2006-2008, 963 subjects from the 3C Study, aged 73 years or more, had an eye examination and will have follow-up eye examinations every 2 years.

MEASUREMENTS

Vascular, genetic and nutritional factors were assessed at baseline (1999-2001) and follow-up examinations of the 3C Study. Eye diseases were classified according to international classifications.

RESULTS

Nutritional status and vascular disease and risk factors were similar between participants and non participants, except for a slight difference in plasma triglycerides and HDL-cholesterol. As expected, the prevalence of eye diseases was high: early and late ARM (28.4 % and 5.6 %, respectively), open-angle glaucoma and treated ocular hypertension (4.8 % and 10.0 %, respectively), cataract extraction (45.2 %), retinopathy (8.4 %), retinal vein occlusion (1.1 %), epiretinal membrane (3.9 %), current use of artificial tears (17.3 %).

CONCLUSIONS

This study confirms the high prevalence of eye diseases in the elderly. Its main strength is the combination of nutritional, vascular and genetic information, collected over a 7 year period of time before the first eye examination. It may help design future interventional studies, which might be common with other age-related disorders, because of common nutritional factors.

Air Pollution and the microvasculature: a cross-sectional assessment of in vivo retinal images in the population-based multi-ethnic study of atherosclerosis (MESA)

BACKGROUND

Long- and short-term exposures to air pollution, especially fine particulate matter (PM(2.5)), have been linked to cardiovascular morbidity and mortality. One hypothesized mechanism for these associations involves microvascular effects. Retinal photography provides a novel, in vivo approach to examine the association of air pollution with changes in the human microvasculature.

METHODS AND FINDINGS

Chronic and acute associations between residential air pollution concentrations and retinal vessel diameters, expressed as central retinal arteriolar equivalents (CRAE) and central retinal venular equivalents (CRVE), were examined using digital retinal images taken in Multi-Ethnic Study of Atherosclerosis (MESA) participants between 2002 and 2003. Study participants (46 to 87 years of age) were without clinical cardiovascular disease at the baseline examination (2000-2002). Long-term outdoor concentrations of PM(2.5) were estimated at each participant's home for the 2 years preceding the clinical exam using a spatio-temporal model. Short-term concentrations were assigned using outdoor measurements on the day preceding the clinical exam. Residential proximity to roadways was also used as an indicator of long-term traffic exposures. All associations were examined using linear regression models adjusted for subject-specific age, sex, race/ethnicity, education, income, smoking status, alcohol use, physical activity, body mass index, family history of cardiovascular disease, diabetes status, serum cholesterol, glucose, blood pressure, emphysema, C-reactive protein, medication use, and fellow vessel diameter. Short-term associations were further controlled for weather and seasonality. Among the 4,607 participants with complete data, CRAE were found to be narrower among persons residing in regions with increased long- and short-term levels of PM(2.5). These relationships were observed in a joint exposure model with -0.8 µm (95% confidence interval [CI] -1.1 to -0.5) and -0.4 µm (95% CI -0.8 to 0.1) decreases in CRAE per interquartile increases in long- (3 µg/m(3)) and short-term (9 µg/m(3)) PM(2.5) levels, respectively. These reductions in CRAE are equivalent to 7- and 3-year increases in age in the same cohort. Similarly, living near a major road was also associated with a -0.7 µm decrease (95% CI -1.4 to 0.1) in CRAE. Although the chronic association with CRAE was largely influenced by differences in exposure between cities, this relationship was generally robust to control for city-level covariates and no significant differences were observed between cities. Wider CRVE were associated with living in areas of higher PM(2.5) concentrations, but these findings were less robust and not supported by the presence of consistent acute associations with PM(2.5).

CONCLUSIONS

Residing in regions with higher air pollution concentrations and experiencing daily increases in air pollution were each associated with narrower retinal arteriolar diameters in older individuals. These findings support the hypothesis that important vascular phenomena are associated with small increases in short-term or long-term air pollution exposures, even at current exposure levels, and further corroborate reported associations between air pollution and the development and exacerbation of clinical cardiovascular disease. Please see later in the article for the Editors' Summary.