Prevalence of age-related maculopathy in the adult population in China: the Beijing eye study

Peripapillary RNFL cross-sectional area and its association with other parameters in a Chinese population

BACKGROUND

Quantitative analysis of retinal nerve fibers is important for the diagnosis and treatment of optic nerve diseases. Peripapillary retinal nerve fiber layer (RNFL) cross-sectional area may give a more accurate quantitative assessment of retinal nerve fibers than RNFL thickness but there have been no previous reports of the peripapillary RNFL cross-sectional area or other parameters. The purpose of the current study was to determine peripapillary RNFL cross-sectional area and its association with other factors in an adult Chinese population.

METHODS

RNFL cross-sectional area was measured during peripapillary circular optical coherence tomography (OCT) scan with a diameter of 12° centered on the optic disc. Correlation between RNFL cross-sectional area and other parameters was evaluated by linear regression analysis in a cross-sectional study of an adult Chinese population.

RESULTS

A total of 2404 eyes from 2404 subjects were examined. Multivariate linear regression analysis showed that larger RNFL cross-sectional area correlated with younger age (p < 0.001), female gender (p = 0.001), no history of diabetes (p = 0.012) and larger optic disc area (p < 0.001).

CONCLUSIONS

Peripapillary RNFL cross-sectional area is correlated positively with optic disc area, suggesting that eyes with larger optic discs have thicker RNFL. Further studies are needed to confirm whether this correlation is due to differences in the numbers of retinal nerve fibers or other factors.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Epidemiology, health policy and public health implications of visual impairment and age-related eye diseases in mainland China

The prevalence of visual impairment (VI) and age-related eye diseases has increased dramatically with the growing aging population in mainland China. However, there is limited comprehensive evidence on the progress of ophthalmic epidemiological research in mainland China to enhance our awareness of the prevention of eye diseases to inform public health policy. Here, we conducted a literature review of the population-based epidemiology of VI and age-related eye diseases in mainland China from the 1st of January 1946 to the 20th of October 2021. No language restrictions were applied. There was significant demographic and geographic variation in the epidemic of VI and age-related eye diseases. There are several factors known to be correlated to VI and age-related eye diseases, including age, gender, family history, lifestyle, biological factors, and environmental exposures; however, evidence relating to genetic predisposition remains unclear. In addition, posterior segment eye diseases, including age-related macular degeneration and diabetic retinopathy, are amongst the major causes of irreversible visual impairments in the senile Chinese population. There remains a significant prevention gap, with only a few individuals showing awareness and achieving optimal medical care with regards to age-related eye diseases. Multiple challenges and obstacles need to be overcome, including the accelerated aging of the Chinese population, the lack of structured care delivery in many underdeveloped regions, and unequal access to care. Despite the progress to date, there are few well-conducted multi-center population-based studies following a single protocol in mainland China, which findings can hopefully provide valuable cues for governmental decision-making and assist in addressing and halting the incidence of VI and age-related eye diseases in China.

The frequency of early age-related macular degeneration and its relationship with dietary pattern in Hunan, China: a cross-sectional study

PURPOSE

To estimate the frequency of age-related macular degeneration (AMD) among people who underwent health examination in Hunan, China and to determine the relationship between dietary pattern and the risk of AMD.

METHODS

The Questionnaire was used to collect dietary data from 56,775 study participants of ≥ 50 years old who underwent health examination at the Department of Health Management, the Third Xiangya Hospital of Central South University between January 2017 and December 2019. The diagnosis of AMD was based on the results of color fundus photography (CFP), spectral-domain optical coherence tomography (OCT) and multispectral imaging (MSI). After excluding participants with incomplete records or other ocular disease that may affect the results of fundus examination, a total of 43,672 study participants were included. The univariate and multivariate logistic regression analyses were used to determine the relationship between dietary pattern and the frequency of AMD.

RESULTS

Among the 43,672 study participants, 1080 (2.5%) had early AMD: the frequencies were 2.6% (n = 674) in men and 2.3% (n = 406) in women; the frequencies were 1.0% (n = 289), 3.6% (n = 401), 9.1% (n = 390) in 50-59, 60-69, ≥ 70 years old, respectively. And the age-standard frequency was 6.6% over the 60 years old in Hunan China. The high-salt intake increased the risk of early AMD [odds ratio (OR) = 1.61, 95% confidence interval (CI) = 1.54-1.68], whereas the intake of meat decreased the risk (OR = 0.90, 95% CI = 0.81-0.99).

CONCLUSION

In Hunan China, there was a high frequency of early AMD detected through health examination over the 60 years old. And high-salt intake increases the risk of early AMD, whereas intake of meat decreases the risk. Modulating the dietary pattern and reducing the salt intake as an AMD prevention strategy warrant further study.

Discovering the Potential of Natural Antioxidants in Age-Related Macular Degeneration: A Review

Age-related macular degeneration (AMD) is a multifactorial disease associated with anatomical changes in the inner retina. Despite tremendous advances in clinical care, there is currently no cure for AMD. This review aims to evaluate the published literature on the therapeutic roles of natural antioxidants in AMD. A literature search of PubMed, Web of Science and Google Scholar for peer-reviewed articles published between 1 January 2011 and 31 October 2021 was undertaken. A total of 82 preclinical and 18 clinical studies were eligible for inclusion in this review. We identified active compounds, carotenoids, extracts and polysaccharides, flavonoids, formulations, vitamins and whole foods with potential therapeutic roles in AMD. We evaluated the integral cellular signaling pathways including the activation of antioxidant pathways and angiogenesis pathways orchestrating their mode of action. In conclusion, we examined the therapeutic roles of natural antioxidants in AMD which warrant further study for application in clinical practice. Our current understanding is that natural antioxidants have the potential to improve or halt the progression of AMD, and tailoring therapeutics to the specific disease stages may be the key to preventing irreversible vision loss.

Relationship between shift work and age-related macular degeneration: a cross-sectional analysis of data from the 5th Korea National Health and Nutrition Examination Survey (2010-2012)

Background

Age-related macular degeneration (AMD) is the leading cause of blindness. Shift work has well-known adverse effects on health. However, few studies have investigated the relationship between shift work and AMD. This study was conducted to investigate the relationship between shift work and AMD.

Methods

This study used aggregated data from the 2010-2012 cycles of the Korea National Health and Nutrition Examination Survey. The work schedules were classified into 2 types: day work and shift work. AMD was determined using fundus photographs. The χ² test and multiple logistic regression analysis were used to assess sex-stratified relationship between shift work and AMD.

Results

The odds ratio (OR) of AMD in male shift workers was higher (1.54 [95% confidence interval, CI: 1.01-2.36]) than that in male day workers after adjusting for covariates. After dividing into subgroups of the shift work pattern, the OR of AMD in male night shift workers was higher (1.75 [95% CI: 1.07-2.85]) than that in male day workers after adjusting for covariates. However, results of the female worker group were not significant.

Conclusions

The results of this study provide limited support for the hypothesis that shift work is related to AMD. Further prospective studies are needed to define the relationship between shift work and AMD.

Regional differences in the global burden of age-related macular degeneration

Background

Age-related Macular Degeneration (AMD) is the leading cause of blindness. This study aims to analyze regional differences on the global burden of AMD and help direct related policy making.

Methods

Disability-adjusted life years (DALY) data were collected from the Global Burden of Disease Study (GBD) 2017 to estimate the AMD burden. Mean education years, human development index (HDI) and Public Health Expenditure were extracted from the Human Development Report 2018, and latitude data were obtained from the Google Earth. These four factors were analyzed to see their importance in regional differences of AMD burden, using Kruskal-Wallis test, Dunn’s multiple comparisons test as well as regression analysis.

Results

Global age-standardized DALY rates have decreased since 2011. Based on the WHO region system, age-standardized DALY rates in African and Eastern Mediterranean region were significantly lower than those of other four regions. Linear regression analysis indicated that age-standardized DALY rates were inversely related to HDI and mean education years.

Conclusions

The age-standardized AMD burden had a decreasing tendency recently. Lower socioeconomic status and fewer education years were associated with higher AMD burden. The finding of this study may highlight the importance of national development and education on relieving AMD burden.

Thickness of individual layers at the macula and associated factors: the Beijing Eye Study 2011

BACKGROUND

Diagnosis and follow-up of retinal diseases may be improved if the thickness of the various retinal layers, in addition to the total retinal thickness, is taken into account. Here we measured the thickness of the macular retinal layers in a population-based study group to assess the normative values and their associations.

METHODS

Using spectral-domain optical coherence tomographic images (Spectralis®, wavelength: 870 nm; Heidelberg Engineering Co, Heidelberg, Germany), we measured the thickness of the macular retinal layers in participants of the population-based Beijing Eye Study without ocular diseases and without systematic diseases, such as arterial hypertension, hyperlipidemia, diabetes mellitus, cardiovascular diseases, previous myocardial infarction, cerebral trauma and stroke. Segmentation and measurement of the retinal layers was performed automatically in each of the horizontal scans.

RESULTS

The study included 384 subjects (mean age:60.0 ± 8.0 years). The mean thickness of the whole retina, outer plexiform layer, outer nuclear layer,retinal pigment epithelium, inner retinal layer and photoreceptor layer was 259.8 ± 18.9 μm, 19.4 ± 3.9 μm, 93.4 ± 9.6 μm, 17.6 ± 1.9 μm, 169.8 ± 18.6 μm, and 90.0 ± 4.2 μm, respectively. In multivariable analysis, the thickness of the foveola and of all retinal layers in the foveal, parafoveal and perifoveal region decreased with older age (all P < 0.05), except for the thickness of the parafoveal outer plexiform layer which increased with age. Men as compared to women had higher thickness measurements of the photoreceptor layer and outer nuclear layer in all areas, and of all layers between the retinal nerve fiber layer and inner nuclear layer in the parafoveal area (all P < 0.05). The associations between the macular retinal layers thickness and axial length were not consistent. The inner plexiform layer was thicker, and the ganglion cell layer and inner nuclear layer were thinner, in the temporal areas than in the nasal areas, CONCLUSIONS: The associations between decreasing thickness of most retinal layers with older age and the correlation of a higher thickness of some retinal layers with male gender may clinically be taken into account.

Design and baseline data of a population-based metabonomics study of eye diseases in eastern China: the Yueqing Ocular Diseases Investigation

Background

China is undergoing a massive transition toward an urban and industrial economy. These changes will restructure the demographics and economy which will eventually influence the future patterns of disease. The risk factors of vision-impairing eye diseases remain ambiguous and poorly understood. Metabolomics is an ideal tool to understand and shed light on the ocular disease mechanisms for earlier treatment. This article aims to describe the design, methodology and baseline data of the Yueqing Ocular Diseases Investigation (YODI), a developed county population-based study to determine the prevalence and primary causes of visual impairment; also with metabonomics analysis we aimed to identify, predict and suggest some preventive biomarkers that cause blindness.

Methods

A population-based, cross-sectional study. Randomized clustering sampling was used to identify adults aged 50 years and older in Xiangyang Town, Yueqing county-level City. The interviews covered demographic, behavioral, ocular risk factors and mental health state. The ocular examination included visual acuity, autorefraction, intraocular pressure, anterior and posterior segment examinations, fundus photography, retinal tomography and angiography, and visual field testing. Anthropometric measurements included height and weight, waist and hip circumference, blood pressure, pulse rate, electrocardiogram, and abdominal ultrasound scan. A venous blood sample was collected for laboratory tests and metabonomics studies.

Results

Of the 5319 individuals recruited for the YODI, 4769 (89.7%) subjects were enrolled for analyses. The median age was 62.0 years, and 45.6% were male. The educational level of illiteracy or semi-illiteracy, primary, middle and high school or above was 29.8%, 45.5%, 20.1%, and 3.3%, respectively. Majority of the participants were female, younger, and less educated when compared with nonparticipants. The average body mass index and waist-hip ratios were 24.4 ± 3.4 kg/m² and 0.9 ± 0.1 respectively. Blood sample collection reached a sample size of 1909 (479 from subjects with self-reported diabetes and 1430 from one-third of the 4290 subjects without self-reported diabetes).

Conclusions

The YODI provides population-based data with a high response rate (89.7%) on the prevalence and primary causes of major vision-impairing eye diseases in developed county areas in eastern China. Metabonomics analysis from YODI will provide further association of metabolic characteristics with the visual impairment eye diseases. The risk prediction model could be created and has the potential to be generalized to developed eastern areas in China for prevention.

Singapore Chinese Eye Study: key findings from baseline examination and the rationale, methodology of the 6-year follow-up series

BACKGROUND/AIMS

In order to address the eye care needs of the increasing numbers of elderly Chinese globally, there is a need for comprehensive understanding on the longitudinal trends of age-related eye diseases among Chinese. We herein report the key findings from the baseline Singapore Chinese Eye Study (SCES-1), and describe the rationale and methodology of the 6-year follow-up study (SCES-2).

METHODS

3353 Chinese adults who participated in the baseline SCES-1 (2009-2011) were invited for the 6-year follow-up SCES-2 (2015-2017). Examination procedures for SCES-2 included standardised ocular, systemic examinations and questionnaires identical to SCES-1. SCES-2 further included new examinations such as optical coherence tomography angiography, and questionnaires to evaluate health impact and economic burden of eye diseases.

RESULTS

In SCES-1, the age-adjusted prevalence of best-corrected low vision (VA<6/12, better-seeing eye) and blindness (VA<6/60, better-seeing eye) were 3.4% and 0.2%, respectively. The prevalence rates for glaucoma, age related macular degeneration, and diabetic retinopathy (among diabetics) were 3.2%, 6.8%, 26.2%, respectively. Of the 3033 eligible individuals from SCES-1, 2661 participated in SCES-2 (response rate=87.7%). Comparing with those who did not attend SCES-2, those attended were younger, had higher SES (all p<0.001), but less likely to be a current smoker, to have diabetes, hypertension, hyperlipidaemia (all p≤0.025).

CONCLUSIONS

Building on SCES-1, SCES-2 will be one of the few longitudinal population-based eye studies to report incidence, progression, and risk factors of major age-related eye diseases. Findings from this cohort may offer new insights, and provide useful reference information for other Chinese populations elsewhere.

Ten-Year Progression of Myopic Maculopathy: The Beijing Eye Study 2001-2011

PURPOSE

To investigate the progression pattern of myopic maculopathy and associated factors in a population-based study.

DESIGN

Population-based longitudinal study.

PARTICIPANTS

The Beijing Eye Study including 4439 participants in 2001 was repeated in 2011, with 2695 individuals (66.4%) being re-examined in 2011.

METHODS

The study participants underwent detailed ophthalmic and general examinations. Using fundus photographs obtained in 2001 and 2011, we assessed the progression of myopic maculopathy in highly myopic eyes with a refractive error ≥-6 diopters in 2001. Myopic maculopathy was differentiated into tessellated fundus (category 1), diffuse chorioretinal atrophy (category 2), patchy chorioretinal atrophy (category 3), and macular atrophy (category 4), with lacquer cracks and choroidal neovascularization as additional plus signs.

MAIN OUTCOME MEASURES

Progression pattern of myopic maculopathy.

RESULTS

Of 110 highly myopic eyes (70 individuals) at baseline, 39 eyes (35.5%) showed progression observed in 15 of 79 eyes (19%) with tessellated fundus at baseline, in 17 of 24 eyes (71%) with diffuse chorioretinal atrophy, in all 6 eyes with patchy chorioretinal atrophy, and the 1 eye with macular atrophy. Lacquer cracks detected in 2 eyes in 2001 developed into a small patchy atrophy (1 eye) or widened during the follow-up (1 eye). Five eyes demonstrated new lacquer cracks. In binary regression analysis, progression of myopic maculopathy was associated with longer axial length (P < 0.001; odds ratio [OR], 7.13; 95% confidence interval [CI], 2.49-20.4), older age (P = 0.001; OR, 1.25; 95% CI, 1.10-1.42), higher prevalence of staphylomas (P = 0.03; OR, 24.3; 95% CI, 2.89-204), smaller parapapillary γ-zone in 2011 (P = 0.01; OR, 0.61; 95% CI, 0.41-0.91), and female gender (P = 0.04; OR, 9.78; 95% CI, 1.06-90.6).

CONCLUSIONS

The 10-year progression rate of myopic maculopathy in this elderly Chinese population was 35.5%, increasing from 15 of 79 eyes (19%) in category 1 of myopic maculopathy at baseline to 17 of 24 eyes (71%) in category 2 and 6 of 6 eyes (100%) in category 3. Risk factors for myopic maculopathy progression were longer axial length, pre-existing staphylomata, smaller parapapillary γ-zone, older age, and female gender.

Prevalence and factors associated with age-related macular degeneration in a southwestern island population of Japan: the Kumejima Study

AIMS

To evaluate the prevalence of and factors associated with age-related macular degeneration (AMD) in a rural population of southwestern Japan.

METHODS

This population-based cross-sectional study of all residents aged 40 years or older was conducted on the island of Kumejima, Okinawa, Japan. Of 4632 eligible residents, 3762 completed a comprehensive questionnaire and underwent ocular examination (participant rate, 81.2%). A non-mydriatic fundus photograph was used to grade AMD lesions according to the Wisconsin protocol. Prevalence of AMD was calculated and factors associated with AMD were identified by logistic regression.

RESULTS

Of 3068 subjects with gradable photographs, 469 had early AMD and 4 had late AMD. Age-adjusted prevalence was 13.4% for any AMD, 13.3% for early AMD and 0.09% for late AMD. In multivariate analysis, any AMD was positively associated with age (OR 1.04 per year, 95% CI 1.03 to 1.05), male sex (OR 1.42, 95% CI 1.14 to 1.75) and history of cataract surgery (OR 1.35, 95% CI 1.00 to 1.82) and was negatively associated with longer axial length (OR 0.85 per millimetre, 95% CI 0.74 to 0.96). Early AMD similarly showed significant associations with these same factors.

CONCLUSIONS

Prevalence of early or late AMD in a southwestern island population of Japan was 13.4% or 0.09%. Our data suggest relatively high prevalence for early AMD and low prevalence for late AMD in this sample of rural Japanese population. Significant factors associated with any or early AMD were mostly similar to that of previous studies.

Prevalence of age-related macular degeneration in rural southern China: the Yangxi Eye Study

PURPOSE

To describe the prevalence of age-related macular degeneration (AMD) among older adults in rural southern mainland China.

METHODS

Eligible persons aged 50 years or over were identified by geographically defined cluster sampling from Yangxi County, Guangdong Province, China. Participants underwent a standardised interview and comprehensive eye examinations from August to November in 2014. Digital retinal photographs were graded for AMD lesions using the Clinical Classification of Age-Related Macular Degeneration developed by the Beckman Initiative for Macular Research Classification Committee. Age-standardised prevalence of AMD and AMD lesions was calculated using the 2010 world population data and compared with those of other populations.

RESULTS

Of 5825 subjects who participated (90.7% response rate), 4881 (83.8%) had fundus photographs gradable for AMD. Early, intermediate and late AMD were present in 2003 (41.0%), 879 (18.0%) and 42 (0.86%) participants. The age-standardised prevalence of early, intermediate and late AMD was 40.4% (95% CI 39.6% to 41.2%), 17.6% (95% CI 17.0% to 18.2%) and 0.79% (95% CI 0.65% to 0.95%), respectively. Total AMD was more prevalent in men than in women (62.8% vs 57.1%).

CONCLUSIONS

AMD is an important public health concern for rural southern China, and the prevalence of AMD was higher in men than in women.

An epidemiological investigation of age-related macular degeneration in aged population in China: the Hainan study

Purpose

The aim of this study was to investigate the prevalence of age-related macular degeneration (AMD) and the risk factors in the residents aged ≥50 years in Hainan Province.

Methods

Random sampling was carried out in four separated cities in Hainan Province in 2015. All the subjects accomplished the standard questionnaire and ocular examinations. The diagnosis of AMD was performed based on the criteria proposed by Beckman Initiative for Macular Research Classification Committee.

Results

Three hundred and fifty-seven subjects (15.6%) were diagnosed with AMD, including 267 (11.7%) of early AMD, 64 (2.80%) of intermediate AMD and 24 (1.1%) of late AMD, respectively. The factors associated with the prevalence of AMD included age, educational level, smoking, outdoor activities and diet. The prevalence of AMD increased with age, lower educational level, smoking or less outdoor activities. The prevalence of AMD in those with a diet of meat or eggs was higher compared with a diet of vegetables or fish. The prevalence of early, intermediate and late AMD in the aged population in Hainan Province was 11.7, 2.8 and 1.1%, respectively.

Conclusions

Age and smoking were the risk factors for AMD, while the educational level and outdoor activities were the protective factors. Early AMD mostly occurred in those aged 50–59 years and 60–69 years, while intermediate and late AMD occurred in 70–79 years and older than 80 years.

Prevalence of age-related macular degeneration in an elderly UK Caucasian population-The Bridlington Eye Assessment Project: a cross-sectional study

ImportanceThere is paucity of data on prevalence and disease asymmetry of age-related macular degeneration (AMD), particularly the earlier stages, in the UK population.Objective and PurposeTo determine the prevalence of age-related macular degeneration in an elderly Caucasian UK population.DesignCross-sectional population study, 2002-2006.ParticipantsResidents in the study area of Bridlington aged 65 years and older.MethodsFull-ophthalmic examination was undertaken in 3549 participants, of eligible 6319 Caucasian population (response rate of 56%). Non-stereoscopic Colour fundus photographs (30°) were graded masked using a modified Rotterdam Classification for 3475 (98%) participants with gradable images. Prevalence for different AMD grades were calculated. Demographic details were analysed then integrated with the AMD gradings for full analysis. Prevalence rates for the different AMD Grades were calculated, as well as the age-specific prevalences.ResultsAMD prevalence in the worst eye were 38.5% grade 0, 41.4% grade 1, 12.8% grade 2, 2.8% grade 3, and 4.6% grade 4. Geographic atrophy (grade 4a) occurred in 2.5%, and neovascular AMD (grade 4b) in 1.8%. Prevalence increased with age such that grade 4 (advanced) AMD was 2.2% in the 65-69 years group, 15.8% for the 85-90, and 21.2% for over 90 years. There was significant asymmetry between the two eyes of individuals with advanced AMD (P<0.001), such that vision loss was unilateral. Persons with more advanced AMD grades were more likely to be dissatisfied with their vision.ConclusionsAdvanced AMD occurs more commonly in the UK Caucasian population than previously reported. Significant asymmetry between the two eyes occurs in individuals with unilateral advanced AMD so that visual impairment statistics do not represent true prevalence of advanced AMD. Persons with more advanced AMD were more likely to be dissatisfied with their vision.

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.

Risk Factors for Progression of Early Age-Related Macular Degeneration in Koreans

PURPOSE

To identify risk factors for the progression of early age-related macular degeneration (AMD) in Koreans.

METHODS

This study was conducted at a health-screening center and followed a prospective cohort study design. Of 10,890 participants older than 50 years, 318 (2.92%) presented with early AMD. Among these 318 participants, we re-examined 172 participants after a mean duration of 4.4 years. Progression was defined by the Age-Related Eye Disease Study (AREDS) simplified AMD severity scale. Multivariable logistic regression was used to examine associations between AMD progression and baseline physical, demographic, behavioral, and ocular characteristics.

RESULTS

Of the 172 participants with early AMD who were re-examined, 34 (19.8%) had progression. Multivariable analyses revealed that current smoking (odds ratio, OR, 7.0, 95% confidence interval, CI, 1.4-34.4, adjusted for age, alcohol consumption, body mass index, BMI, blood pressure, BP, total cholesterol, and high density lipoprotein, HDL, cholesterol) and hypertension (OR 10.3, 95% CI 1.9-55.7, adjusted for age, smoking status, alcohol consumption, BMI, total cholesterol, and HDL cholesterol) were independently associated with progression of early AMD. Additionally, the presence of a central drusen lesion within one-third disc diameter of the macula (age-adjusted OR 4.8, 95% CI 1.3-17.6) and 20 or more drusen (age adjusted OR 7.8, 95% CI 2.5-24.0) were independently associated with progression of early AMD.

CONCLUSION

Current smoking, hypertension, central drusen location, and increasing number of drusen were associated with an increased risk of early AMD progression in Koreans.

Assessment of Choroidal Microstructure and Subfoveal Thickness Change in Eyes With Different Stages of Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is a major cause of irreversible blindness. Choroidal structural changes seem to be inevitable in AMD pathogenesis. Our study revealed associated choroidal microstructural changes in AMD eyes.The aim of the study was to compare choroidal microstructural changes in eyes with AMD of different stages.The study was a retrospective, cross-sectional case series.The participants comprised of 32 age-matched normal eyes as controls, and 26 fellow uninvolved eyes of intermediate/late AMD, 29 of early AMD, 28 of intermediate AMD, and 39 of late AMD.All subjects underwent comprehensive ophthalmologic examination. The choroid images, including subfoveal choroidal thickness, percentage of Sattler layer area, and en face images of the choroid, were obtained using spectral-domain optical coherence tomography.The main outcome measures were subfoveal choroidal thickness changes, percentage of Sattler layer area changes, and en face images of the choroid in AMD eyes.One hundred fifty-four eyes of 96 individuals with mean age of 67.1±9.2 years were included. The mean subfoveal choroidal thickness was 295.4 ± 56.8 μm in age-matched normal eyes, 306.7 ± 68.4 μm in fellow uninvolved eyes with AMD, 293.8 ± 80.4 μm in early AMD, 215.6 ± 80.4 μm in intermediate AMD, and 200.4 ± 66.6 μm in late AMD (F = 14.2, all P < 0.001). Choroidal thickness was greater in early AMD eyes than in intermediate/late AMD eyes (P < 0.001). Mean percentage of Sattler layer area in each group showed a similar tendency. Microstructure of the choroid showed reduced vascular density of Sattler layer areas in late AMD eyes compared with normal eyes.Decreasing subfoveal choroidal thickness and percentage of Sattler layer area were demonstrated in the progression of AMD. The choroidal change was related to atrophy of the microstructural changes of underlying capillaries and medium-sized vessels.

The prevalence and risk factors for age-related macular degeneration in rural-urban India, Sankara Nethralaya Rural-Urban Age-related Macular degeneration study, Report No. 1

PurposeTo report the age- and gender-adjusted prevalence rates of early and late age-related maculopathy (ARM) and associated risk factors in rural and urban Indian population.MethodsA population-based cross-sectional study was carried out in South India between 2009 and 2011. Of the 6617 subjects ≥60 years enumerated ones, 5495 (83.04%) participated in the eye examination. A detailed history including data on demographic, socioeconomic, and ocular history was obtained. Participants underwent detailed ophthalmic evaluation including 30° 3-field photograph as per Age-Related Eye Disease Study protocol. The ARM was graded according to the International ARM Epidemiological Study Group.ResultsAge- and gender-adjusted prevalence of early ARM was 20.91% (20.86-20.94) in the rural population and 16.37% (16.32-16.42) in the urban population. Similarly, the prevalence of late ARM was 2.26% (2.24-2.29) and 2.32% (2.29-2.34) in the rural and urban population, respectively. In both rural and urban populations, risk factors that were related to both early and late ARM were age, per year increase (OR, range 1.00-1.08); middle socioeconomic status (OR, range 1.05-1.83); and smokeless tobacco (OR, range 1.11-2.21). Protective factor in both was the presence of diabetes mellitus in all ARM (OR, range 0.34-0.83). Risk factors, only in the rural arm, were female gender (OR, range 1.06-1.64), past smoker (OR, 1.14), and serum low-density lipoprotein cholesterol level (OR, 1.03).ConclusionsThe study reports smokessless tobacco as a risk factor for both early and late ARM and identified a higher prevalence of early ARM in the rural population compared with urban population.

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.

Measurement of macular pigment optical density among healthy Chinese people and patients with early-stage age-related macular degeneration

AIM

To measure the macular pigment optical density (MPOD) in healthy Chinese people and patients with early age-related macular degeneration (AMD).

METHODS

Cross-sectional population based study. Demographic and lifestyle characteristics were ascertained by questionnaire. A food frequency questionnaire was completed for all participants. Participants underwent general physical and ophthalmic examinations and MPOD was measured by heterochromatic flicker photometry. Foveal architecture was measured by optical coherence tomography.

RESULTS

MPOD of 225 participants (122 healthy and 103 early AMD) was 0.48±0.18. Patients with early AMD (0.52±0.19) tended to have higher MPOD levels than healthy people (0.47±0.17), but the difference was not statistically significant (P=0.06). Participants with carrot or corn oil intake every week tended to have higher levels of MPOD (P=0.002 and 0.008 respectively) while those with corn intake had relatively lower level of MPOD (P=0.01). MPOD increased with the center foveal thickness (P=0.01).

CONCLUSION

Our findings show that there is no statistically significant association between MPOD and early AMD in the studied population. MPOD is related to center foveal thickness and diets would influence MPOD levels.

Ancestry of the Timorese: age-related macular degeneration associated genotype and allele sharing among human populations from throughout the world

We observed that the third leading cause of blindness in the world, age-related macular degeneration (AMD), occurs at a very low documented frequency in a population-based cohort from Timor-Leste. Thus, we determined a complete catalog of the ancestry of the Timorese by analysis of whole exome chip data and haplogroup analysis of SNP genotypes determined by sequencing the Hypervariable I and II regions of the mitochondrial genome and 17 genotyped YSTR markers obtained from 535 individuals. We genotyped 20 previously reported AMD-associated SNPs in the Timorese to examine their allele frequencies compared to and between previously documented AMD cohorts of varying ethnicities. For those without AMD (average age > 55 years), genotype and allele frequencies were similar for most SNPs with a few exceptions. The major risk allele of HTRA1 rs11200638 (10q26) was at a significantly higher frequency in the Timorese, as well as 3 of the 5 protective CFH (1q32) SNPs (rs800292, rs2284664, and rs12066959). Additionally, the most commonly associated AMD-risk SNP, CFH rs1061170 (Y402H), was also seen at a much lower frequency in the Korean and Timorese populations than in the assessed Caucasian populations (C ~7 vs. ~40%, respectively). The difference in allele frequencies between the Timorese population and the other genotyped populations, along with the haplogroup analysis, also highlight the genetic diversity of the Timorese. Specifically, the most common ancestry groupings were Oceanic (Melanesian and Papuan) and Eastern Asian (specifically Han Chinese). The low prevalence of AMD in the Timorese population (2 of 535 randomly selected participants) may be due to the enrichment of protective alleles in this population at the 1q32 locus.

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.

Analysis of short-term change in subfoveal choroidal thickness in eyes with age-related macular degeneration using optical coherence tomography

BACKGROUND AND OBJECTIVE

To measure the subfoveal choroidal thickness in patients with age-related macular degeneration (AMD) over 6 months.

PATIENTS AND METHODS

A retrospective, observational study of patients with AMD followed up for 6 months at the New England Eye Center. Baseline and 6-month follow-up subfoveal choroidal thickness was measured using spectral-domain OCT and compared.

RESULTS

For the entire cohort, there was statistically significant thinning of the subfoveal choroidal thickness at 6 months compared to baseline that was driven by the cohort of patients with neovascular AMD (181.2 ± 75 μm to 173.4 ± 63 μm; P = .049).

CONCLUSION

There was a statistically significant decrease in subfoveal choroidal thickness observed in this cohort of patients with AMD over 6 months, but it was driven by the subgroup of patients with neovascular age-related macular degeneration.

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.

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.

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.

Snoring and glaucoma

Purpose

To examine a potential association between snoring and glaucoma in a population-based setting.

Methods

The population-based Beijing Eye Study 2011 included 3468 subjects with an age of 50+ years. The participants underwent a detailed ophthalmic examination. Glaucoma was determined according to the ophthalmoscopic appearance of the optic nerve head. Snoring assessed in an interview was graded into “severe snoring”, “moderate snoring”, and “no snoring”.

Results

Data on snoring and glaucoma were available for 3146 subjects. Snoring was reported for 1787 (66.8%) subjects, with moderate snoring reported for 1384 (44.0%) subjects and severe snoring for 403 (12.8%) subjects. In multivariate analysis, prevalence of severe snoring was significantly associated with male gender (P = 0.002; regression coefficient B: 0.36; Odds ratio (OR): 1.44 (95% confidence interval (CI): 1.14, 1.81)), higher body mass index (P<0.001; B: 0.12; OR: 1.13 (95%CI: 1.09, 1.16)), higher systolic blood pressure (P<0.001; B: 0.01; OR: 1.01 (95%CI: 1.005, 1.02)), younger age (P = 0.007; B: −0.018; OR: 0.98 (95%CI: 0.97, 0.995)), and higher cognitive function (P = 0.03; B: 0.04; OR: 1.04 (95%CI: 1.004, 1.08)), however it was not significantly associated with the prevalence of open-angle glaucoma (P = 0.10; B: −0.63; OR: 0.53 (95%CI: 0.25, 1.12)). Prevalence of severe snoring was neither significantly associated with the prevalence of angle-closure glaucoma (P = 0.65), retinal vein occlusions (P = 0.24), neuroretinal rim area (P = 0.19), retinal nerve fiber layer thickness (P = 0.16) nor vertical cup/disc ratio (P = 0.64).

Conclusions

Severe snoring was not significantly associated with the prevalence of open-angle glaucoma, angle-closure glaucoma or retinal vein occlusions after adjustment for age, gender, body mass index, systolic blood pressure and cognitive function score. Our population-based study did not reveal that snoring was a risk factor for glaucoma and thus did not provide a reason to assess or to treat snoring in patients with glaucoma.

Retinal nerve fibre layer thickness measured by Spectralis spectral-domain optical coherence tomography: The Beijing Eye Study

PURPOSE

The aim of this study was to measure retinal nerve fibre layer thickness (RNFLT) and its associated factors in a population-based setting.

METHODS

The population-based Beijing Eye Study 2011 included 3468 individuals. The study participants underwent spectral-domain optical coherence tomography (Spectralis(®) ; Spectralis OCT)-assisted measurement of the RNFLT. For this study, exclusion criteria were glaucoma, pseudoexfoliation, best-corrected visual acuity of >0.5 logMAR, macular diseases, previous ocular surgery and known neurological diseases. The only inclusion criterion was an age of 50+ years.

RESULTS

The inclusion criteria were fulfilled by 2548 participants. Mean RNFLT was 102 ± 11 μm. RNFLT was significantly (p < 0.001) thicker in the temporal inferior sector (153 ± 21 μm) than in the temporal superior sector (138 ± 21 μm), nasal inferior sector (118 ± 24 μm), nasal superior sector (106 ± 21 μm), temporal sector (76 ± 13 μm) and nasal sector (73 ± 15 μm). The mean intereye difference in RNFLT was 4.4 ± 6.0 μm. In multivariate analysis, thicker RNFLT was associated with younger age (p < 0.001), female gender (p < 0.001), urban region (p = 0.003), larger optic disc size (p < 0.001), larger neuroretinal rim area (p < 0.001), hyperopic refractive error (p < 0.001), larger beta zone of parapapillary atrophy (p = 0.008) and thicker subfoveal choroidal thickness (p = 0.02). RNFLT decreased by about 0.2 μm (0.2%) per year of life and by 1 μm (1%) per dioptre of myopia.

CONCLUSION

Mean RNFLT (measured by Spectralis(®) OCT; 102 ± 11 μm) was associated with younger age, female gender, urban region of habitation, larger optic disc, larger rim, hyperopic refractive error, larger parapapillary beta zone and thicker subfoveal choroidal thickness. Independent of age and refractive error, the RNFL was thickest temporal inferiorly and thinnest temporally and nasally.

Parapapillary atrophy in patients with intracranial tumours

PURPOSE

To examine size and frequency of parapapillary atrophy (beta zone) in patients with intrasellar or perisellar tumours and a glaucoma-like appearance of the intrapapillary optic disc region.

METHODS

Thirty-four Chinese subjects with intrasellar or perisellar tumours and a glaucoma-like appearance of the intrapapillary optic disc region and 129 age-matched subjects randomly selected from the population-based Beijing Eye Study were enrolled. Beta zone was measured on fundus photographs. Size and location of the tumours were assessed on neuroradiological images.

RESULTS

Beta zone was significantly more common (79 ± 7% versus 46 ± 4%; p = 0.001), and it was significantly larger in the tumour group than in the control group (circumferential extent: 135 ± 99 versus 57 ± 72; p < 0.001; relative area: 1856 ± 1923 versus 759 ± 1390; p = 0.002). The width of the intracerebral tumours was significantly associated with the circumferential extent of beta zone (r = 0.36, p = 0.039) and with the area of beta zone (r = 0.37, p = 0.032). Tumour width, height and depth were significantly (p = 0.001; p = 0.012; and p < 0.001, respectively) larger in the group of patients with beta zone than in the subgroup of patients without beta zone of parapapillary atrophy.

CONCLUSIONS

Patients with large intrasellar or perisellar tumours and a glaucoma-like appearance of the intrapapillary region as compared with a population-based control group had a significantly larger and more frequently occurring beta zone of parapapillary atrophy. It suggests that large parasellar or suprasellar tumours can be associated with typical glaucomatous abnormalities in the parapapillary and intrapapillary region of the optic nerve head. It may give hints for the pathogenesis of glaucomatous optic neuropathy.

Localized retinal nerve fiber layer defects detected by optical coherence tomography: the Beijing eye study

Objective

To assess the prevalence of localized retinal nerve fiber layer defects (LRNFLD) and associated factors in adult Chinese.

Methods

The population-based Beijing Eye Study 2011 included 3468 individuals (mean age: 64.6±9.8 years (range: 50–93 years)). The study participants underwent a detailed ophthalmological examination including spectral-domain optical coherence tomography (Spectralis^R-OCT) assisted measurement of the RNFL. A LRNFLD was defined as a sector in which the RNFL contour line dipped into the red zone for a length of <180°.

Results

Readable OCT images were available for 3242 (93.5%) subjects. LRNFLDs were detected in 640 eyes (9.9±0.4%) of 479 subjects (14.8±0.6%). In the age groups of 50–59 years, 60–69 years, 70–79 years, and 80+ years, the prevalence of LRNFLD per person increased from 9.9±0.9%, 11.6±1.0% and 20.6±1.4% to 33.0±3.2%, respectively. In multivariate analysis, prevalence of LRNFLDs was significantly associated with older age (P = 0.001; Odds Ratio (OR): 1.03; 95% Confidence Interval (CI): 1.01,1.05), myopic refractive error (P<0.001;OR:0.79;95%CI:0.74,0.85), larger beta zone of parapapillary atrophy (P<0.001; OR:1.34;95%CI:1.20,1.50), presence of glaucomatous optic neuropathy (P<0.001;OR:7.02;95%CI:3.87,12.7), presence of non-glaucomatous optic nerve damage (P = 0.001;OR:43.3;95%CI:8.24,227.1), and presence of diabetic retinopathy (P = 0.003;OR:2.79;95%CI:1.43,5.44).

Conclusions

OCT-defined LRNFLDs were present in a prevalence of 14.8±0.6% in a population-based study sample of subjects aged 50+ years. Prevalence of LRNFLDs increased with higher age, myopic refractive error, and larger parapapillary beta zone. Major ocular diseases associated with LRNFLs were glaucoma, non-glaucomatous optic nerve damage and diabetic retinopathy. These data may be helpful for a semiautomatic assessment of the RNFL.

Retinal nerve fiber layer thickness. The Beijing Eye Study 2011

PURPOSE

To measure retinal nerve fiber layer (RNFL) thickness in a population-based setting.

METHODS

In the population-based Beijing Eye Study 2011 with 3468 individuals, RNFL thickness was measured in a subgroup of 1654 (47.7%) study participants by spectral domain optical coherence tomography (iVue SD-OCT).

RESULTS

Mean RNFL thickness was significantly (P<0.001) higher in the inferior sector (131.4±20.6 µm) than the superior sector (126.1±19.1 µm), where it was higher than in the temporal sector (79.8±12.2 µm;P<0.001), where it was higher than in the nasal sector (75.1±12.6 µm;P<0.001). In multivariate analysis, mean global RNFL thickness (103.2±12.6 µm) increased significantly with younger age (standardized correlation coefficient beta:-0.30;P<0.001), larger neuroretinal rim area (beta:0.26;P<0.001), shorter axial length (beta:-0.21;P<0.001), thicker subfoveal choroidal thickness (beta:0.15;P<0.001), larger optic disc area (beta:0.10;P<0.001), less refractive lens power (beta:0.10;P<0.001), flatter anterior cornea (beta:0.07;P = 0.01) and female gender (beta:0.05;P = 0.03). In this population with an age of 50+ years, the age-related decline in RNFL thickness was 0.5 µm per year of life or 0.36% of an original RNFL thickness of 137 µm at baseline of the study at 50 years of age. Mean global RNFL thickness decreased by 2.4 µm for each mm enlargement of axial length.

CONCLUSIONS

The RNFL profile shows a double hump configuration with the thickest part in the inferior sector, followed by the superior sector, temporal sector and nasal sector. Factors influencing global RNFL thickness were younger age, larger neuroretinal rim, shorter axial length, thicker subfoveal choroid, larger optic disc, less refractive lens power, flatter anterior cornea and female gender. Beyond an age of 50+ years, RNFL decreased by about 0.3% per year of life at an age of 50+ years and by 2.4 µm per mm of axial elongation. These findings may be of interest for the knowledge of the normal anatomy of the eye and may be of help to diagnose diseases affecting the RNFL.

Ocular perfusion pressure and choroidal thickness in eyes with polypoidal choroidal vasculopathy, wet-age-related macular degeneration, and normals

PURPOSE

To measure the choroidal thickness and ocular perfusion pressure in eyes with polypoidal choroidal vasculopathy (PCV), wet-age-related macular degeneration (AMD), and age-matched normal subjects, and look for a possible association between the two.

METHODS

This was a prospective study including 22 eyes with PCV, 33 eyes with wet-AMD, and 35 age-matched normal eyes. Choroidal thickness was measured using enhanced depth imaging (EDI) with spectral-domain optical coherence tomography (SD OCT). Mean ocular perfusion pressure (MOPP) was calculated using the mathematical formula 2/3[DBP+1/3{SBP × DBP}]-IOP (DBP-diastolic blood pressure, SBP-systolic blood pressure, IOP-intraocular pressure). Analyses were carried out using SPSS 14 software and comparisons of mean made using't' tests.

RESULTS

Eyes with PCV showed increased (285.9 μm; subfoveal) choroidal thickness, whereas eyes with wet-AMD (119.4 μm; subfoveal) showed reduced choroidal thickness in comparison with normal eyes (186.77 μm; subfoveal). MOPP in the PCV group was 57.85 mm Hg (P value 0.00), in the wet-AMD group was 52.1 mm Hg (P-value 0.12), and in the normal group was 49.79 mm Hg.

CONCLUSION

It is postulated that higher MOPP in eyes with PCV could have an etiologic implication in disease manifestation and progression. Larger studies with longer follow-up may help validate these findings.

Ophthalmoscopic assessment of the retinal nerve fiber layer. The Beijing Eye Study

Purpose

To examine the retinal nerve fiber layer (RNFL) ophthalmoscopically, to search for localized RNFL defects, and to assess factors associated with RNFL visibility in a population-based setting.

Methods

The population-based cross-sectional Beijing Eye Study 2006 included 3251 subjects. Using color fundus photographs, RNFL visibility was assessed in grades from 0 to 8 in 8 fundus sectors. Localized RNFL defects were defined as wedge-shaped defects running towards the optic disc.

Results

After exclusion of subjects with optic media opacities, 2602 subjects (mean age:58.1±9.0 years) were included. RNFL visibility score was highest (P<0.001) in the temporal inferior region, followed by the temporal superior region, nasal superior region, and nasal inferior region. In multivariate analysis, higher RNFL visibility score was associated with younger age (P<0.001;standardized coefficient beta:−0.44;regression coefficient B: −0.22; 95%CI: −0.24, −0.20), female gender (P<0.001;beta:0.11;B:1.00;95%CI:0.67,1.32), higher blood concentration of low-density lipoproteins (P = 0.002;beta:0.07;B:0.34;95%CI:0.13,0.56), absence of dyslipidemia (P = 0.001;beta: −0.07;B: −0.58;95%CI: −0.93, −0.24), lower blood glucose concentration (P = 0.006;beta: −0.05;B: −0.14;95%CI: −0.24, −0.04), hyperopic refractive error (P<0.001;beta:0.15;B:0.45;95%CI:0.34,0.56), smaller optic disc size (P<0.001;beta: −0.08; B:−0.72;95% CI:−1.04, −0.40), absence of glaucomatous optic neuropathy (P<0.001;beta: −0.06;B: −2.69;95%CI:–4.18, −1.21) and absence of non-glaucomatous optic nerve damage (P = 0.001;beta: −0.06;B: −4.80;95%CI:0. −7.64, −1.96). Localized RNFL defects were detected in 96 subjects (prevalence:3.7±0.45% (95% confidence interval(CI):3.0,4.4). In multivariate analysis, prevalence of localized RNFL defects was associated with higher blood pressure (P<0.001; odds ratio (OR):1.07;95%CI:1.03,1.10), higher concentration of low-density lipoproteins (P = 0.01;OR:1.42;95%CI:1.08,1.85), higher prevalence of glaucomatous optic neuropathy (P<0.001;OR:46.8;95%CI:19.4,113) and diabetic retinopathy (P = 0.002;OR:3.20;95%CI:1.53,6.67), and lower total RNFL visibility (P<0.001;OR:0.92;95%CI:0.88,0.96).

Conclusions

In Chinese aged 45+ years, a decreased RNFL visibility was associated with older age, male gender, dyslipidemia, hyperglycemia, myopia, larger optic disc, and glaucomatous or non-glaucomatous optic neuropathy. Localized RNFL defects (prevalence:3.7±0.45%) were correlated mainly with higher blood pressure, higher concentration of low-density lipoproteins, glaucomatous optic neuropathy and diabetic retinopathy. These data are helpful for the routine ophthalmoscopic examination of the RNFL.

Dietary sources of lutein and zeaxanthin carotenoids and their role in eye health

The eye is a major sensory organ that requires special care for a healthy and productive lifestyle. Numerous studies have identified lutein and zeaxanthin to be essential components for eye health. Lutein and zeaxanthin are carotenoid pigments that impart yellow or orange color to various common foods such as cantaloupe, pasta, corn, carrots, orange/yellow peppers, fish, salmon and eggs. Their role in human health, in particular the health of the eye, is well established from epidemiological, clinical and interventional studies. They constitute the main pigments found in the yellow spot of the human retina which protect the macula from damage by blue light, improve visual acuity and scavenge harmful reactive oxygen species. They have also been linked with reduced risk of age-related macular degeneration (AMD) and cataracts. Research over the past decade has focused on the development of carotenoid-rich foods to boost their intake especially in the elderly population. The aim of this article is to review recent scientific evidences supporting the benefits of lutein and zexanthin in preventing the onset of two major age-related eye diseases with diets rich in these carotenoids. The review also lists major dietary sources of lutein and zeaxanthin and refers to newly developed foods, daily intake, bioavailability and physiological effects in relation to eye health. Examples of the newly developed high-lutein functional foods are also underlined.

Asian Age-Related Macular Degeneration: Current Concepts and Gaps in Knowledge

Data on the epidemiology and treatment of age-related macular degeneration (AMD) in Asian populations have been scarce. Recently, significant advances in the current knowledge of AMD in Asia have been made, but deficiencies in important areas remain. Epidemiological data on AMD in those 80 years or older are lacking.There are also few incidence data on AMD or polypoidal choroidal vasculopathy (PCV), an important variant of AMD that seems to be more common in Asia. The risk factors for PCV have not been clearly defined to the extent that those for AMD have. No trials of nutritional supplementation for AMD prevention in Asia exist, and there is also a lack of long-term clinical trial data on combination therapy for PCV and indeed very few trial data on PCV. These represent opportunities for future research. With aging populations in Asia, increased data on the prevalence, risk factors, prevention, and treatment of AMD and PCV in Asian populations will be needed to formulate evidence-based public health and clinical guidelines.

Prevalence and risk factors of early-stage age-related macular degeneration in patients examined at a health promotion center in Korea

We evaluated the prevalence and risk factors for early age-related macular degeneration (AMD) in Koreans 50 yr of age or older who were examined at a single health promotion center. We retrospectively reviewed the records of 10,449 subjects who visited the center over a 6-month period. Fundus photography was performed on all subjects, and systematic risk factor analysis was conducted using a structured questionnaire. All patients (n = 322) were initially diagnosed with drusen or early AMD using fundoscopy; the control group (n = 10,127) were those yielding normal fundoscopy findings. The age- and gender-adjusted prevalence of early AMD was 3.08%. Advanced age, male gender, smoking status, hyperlipidemia, working outdoors, and residence in rural areas were all significantly associated with an increased risk for development of early AMD. Higher-level ingestion of fruit or herbal medication and an increased amount of exercise were associated with a lower risk of early AMD development. In our Korean cohort, consisting principally of relatively healthy, middle-class urban adults, the prevalence of early AMD was 3.08% that is similar to that reported in earlier epidemiological studies. Several modifiable risk factors such as smoking and hyperlipidemia are associated with the prevalence of early AMD in our cohort.

Evaluation of new and established age-related macular degeneration susceptibility genes in the Women's Health Initiative Sight Exam (WHI-SE) Study

PURPOSE

To assess whether established and newly reported genetic variants, independent of known lifestyle factors, are associated with the risk of age-related macular degeneration (AMD) among women participating in the Women's Health Initiative Sight Exam (WHI-SE) Genetic Ancillary Study.

DESIGN

Multicenter case-control study.

METHODS

One hundred and forty-six women with intermediate and late stages of AMD and 1269 subjects without AMD underwent ocular examinations and fundus photography to determine stage of AMD. Fourteen polymorphisms at or near 11 genes, including previously confirmed genes CFH, ARMS2/HTRA1, C2, C3, and CFI; recently reported AMD genes in the high-density lipoprotein cholesterol (HDL) pathway LIPC, ABCA1, CETP, and LPL; TIMP3/SYN3, a known ocular gene recently linked with AMD; and APOE, were assessed using logistic regression analysis.

RESULTS

After adjustment for demographic, behavioral, and other genetic factors, a protective effect was detected among TT carriers compared with non-carriers for the HDL pathway gene, LIPC rs493258, for intermediate and late AMD (OR [95% confidence interval]: 0.3 [0.2-0.7], P = .003). Variants in CFH rs1410996, ARMS2/HTRA1 A69S, and C3 R102G were significantly associated with an increased risk of AMD. Individuals with the homozygous CFI rs10033900 TT genotype had a 2.9 [1.2-7.2]-fold increased risk, and those with the CFH Y402H GG genotype had a 2.2 [1.0-4.8]-fold higher risk of developing AMD compared with non-carriers. APOE4 carriers may have a reduced risk of intermediate/late AMD (OR = 0.5 [0.3-0.9], P = .015. Suggestive associations were seen between AMD and the HDL pathway genes CETP and LPL.

CONCLUSION

In this unique national cohort of women, we found associations with established AMD-related genetic factors and the recently reported LIPC gene in the HDL pathway. These findings may help develop novel therapeutic targets to treat or delay the onset of the disease.

Prevalence of eye diseases in South Korea: data from the Korea National Health and Nutrition Examination Survey 2008-2009

PURPOSE

The aim of this study is to report on preliminary data regarding the prevalence of major eye diseases in Korea.

METHODS

We obtained data from the Korea National Health and Nutrition Examination Survey, a nation-wide cross-sectional survey and examinations of the non-institutionalized civilian population in South Korea (n = 14,606), conducted from July 2008 to December 2009. Field survey teams included an ophthalmologist, nurses, and interviewers, traveled with a mobile examination unit and performed interviews and ophthalmologic examinations.

RESULTS

The prevalence of visual impairment, myopia, hyperopia and astigmatism in participants over 5 years of age was 0.4 ± 0.1%, 53.7 ± 0.6%, 10.7 ± 0.4%, and 58.0 ± 0.6%, respectively. The prevalence of strabismus and blepharoptosis in participants over 3 years of age was 1.5 ± 0.1% and 11.0 ± 0.8%, respectively. In participants over 40 years of age, the prevalence of cataract, pterygium, early and late age-related macular degeneration, diabetic retinopathy and glaucoma was 40.2 ± 1.3%, 8.9 ± 0.5%, 5.1 ± 0.3%, 0.5 ± 0.1%, 13.4 ± 1.5%, and 2.1 ± 0.2%, respectively.

CONCLUSIONS

This is the first nation-wide epidemiologic study conducted in South Korea for assessment of the prevalence of eye diseases by both the Korean Ophthalmologic Society and the Korea Center for Disease Control and Prevention. This study will provide preliminary information for use in further investigation, prevention, and management of eye diseases in Korea.

Dyslipidemia and eye diseases in the adult Chinese population: the Beijing eye study

To determine associations between dyslipidemia and ocular diseases, the population-based Beijing Eye Study 2006 examined 3251 subjects (age≥45 years) who underwent a detailed ophthalmic examination and biochemical blood analysis. Dyslipidemia was defined as any of the following: hypercholesterolemia (total cholesterol concentration≥5.72 mmol/L (220 mg/dL)) or hypertriglyceridemia (triglyceride concentration≥1.70 mmol/L (150 mg/dL)) or low high-density lipoprotein-cholesterol (HDL-C concentration≤0.91 mmol/L (35 mg/dL)). Biochemical blood examinations were available for 2945 (90.6%) subjects. After adjustment for age, gender, habitation region, body mass index, self reported income, blood glucose concentration, diastolic blood pressure and smoking, dyslipidemia was significantly associated with higher intraocular pressure (P<0.001) and beta zone of parapapillary atrophy (P = 0.03). Dyslipidemia was not significantly associated with the prevalence of glaucoma (P = 0.99), retinal vein occlusions (P = 0.92), diabetic retinopathy (P = 0.49),presence of retinal vascular abnormalities such as focal or general arteriolar narrowing, age-related macular degeneration(P = 0.27), nuclear cataract (P = 0.14), cortical cataract (P = 0.93), and subcapsular cataract (P = 0.67). The results make one conclude that, controlled for systemic and socioeconomic parameters, dyslipidemia was not associated with common ophthalmic disorders including glaucoma and age-related macular degeneration.

Analysis of choroidal thickness in age-related macular degeneration using spectral-domain optical coherence tomography

PURPOSE

To understand the relationship between choroidal thickness and various disease factors in patients with age-related macular degeneration (AMD) using spectral-domain optical coherence tomography.

DESIGN

Cross-sectional, retrospective analysis.

METHODS

Fifty-seven eyes of 47 patients with wet and dry AMD seen between November 2009 and January 2010 at the New England Eye Center, Boston, Massachusetts, were analyzed. Choroidal thickness was measured by 2 independent observers at 11 sites with high-definition horizontal 1-line raster scans through the foveal center. A retrospective chart review was performed to obtain data concerning duration of disease, number of intravitreal anti-vascular endothelial growth factor injections, visual acuity, lens status, and concomitant retinal pathologic features. The Pearson correlation and Student t test were used for statistical analysis for assessment of choroidal thickness changes in wet and dry AMD.

RESULTS

The choroid in eyes with wet and dry AMD demonstrated a wide range of thicknesses above and below the normal mean (range, 77.5 to 399.5 μm; standard deviation [SD], 90.2). Nearly one third (33.3%) of the eyes with AMD measured less than 1 SD below the mean. Eyes with wet AMD demonstrated a mean subfoveal choroidal thickness of 194.6 μm (SD, 88.4; n = 40) compared with 213.4 μm (SD, 92.2; n = 17) in the dry AMD group. The choroidal thickness in eyes with dry AMD was correlated inversely with age (r = -0.703; P = .002); however, analysis of the number of intravitreal anti-vascular endothelial growth factor injections, number of years of disease, and visual acuity failed to demonstrate any significant correlations with choroidal thickness.

CONCLUSIONS

This study demonstrated that choroidal thickness can be measured by spectral-domain optical coherence tomography and that variable choroidal thickness exists among patients with the clinical diagnosis of wet and dry AMD. However, it is unclear at this time why in some eyes, choroidal thickness either increases or decreases with the disease. Further studies need to be carried out to understand the significance of choroidal thickness with respect to visual function and disease progression over time.