16 research outputs found

    Age-related Macular Degeneration in Older Populations: Long-Term Incidence, Progression and Associations

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    Purpose: To assess the long-term incidence and progression of age-related macular degeneration (AMD) and its associated factors. Methods: The Blue Mountains Eye Study is a population-based cohort study of older Australians (n=3654) with 15-year follow-up. The presence and characteristics of AMD lesions were assessed from fundus photographs taken at each visit using the Wisconsin Age-Related Maculopathy Grading System. Results: After adjusting for competing risk of death, the 15-year incidence of early and late AMD were 15.1% and 4.1%, respectively. Larger macular areas involved by, and central location of early AMD lesions, and the co-presence of two lesion types, predicted increased progression to late AMD. A milder spectrum of early AMD was found in Singaporeans compared to Australians. Smoking was consistently found associated with incidences of late AMD, geographic atrophy and reticular drusen, and with the progression from unilateral to bilateral involvement in 5 years. Weekly fish consumption and high intake of dietary lutein-zeaxanthin were associated with reduced risks of late AMD, after controlling for other risk factors. Conclusion: This thesis work provides in-depth knowledge of long-term trajectory of AMD lesions and factors associated with their progression, including modifiable factors that could be intervened to prevent blindness from this condition

    Association of dietary nitrate intake with the 15-year incidence of age-related macular degeneration

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    Background Dietary nitrate, found predominantly in green leafy vegetables and beetroot, is a precursor of nitric oxide. Under- or overproduction of nitric oxide is implicated in the etiology of several eye diseases. However, the potential influence of dietary nitrate intake on age-related macular degeneration (AMD) risk has not been assessed. Objective To investigate the temporal association between dietary nitrate intake (from both vegetable and nonvegetable sources) and the 15-year incidence of AMD, independent of potential confounders. Design A longitudinal cohort study conducted from 1992-1994 to 2007-2009. Participants/setting The Blue Mountains Eye Study is a population-based study of adults aged 49+ at baseline, from a region west of Sydney, Australia. At baseline, 2,856 participants with complete dietary data and AMD information were examined, and of these, 2,037 participants were re-examined 15 years later and thus included in incidence analysis. Main outcomes measured Incidence of AMD (main outcome) was assessed from retinal photographs. Dietary intake was assessed using a semiquantitative food-frequency questionnaire. Nitrate intake from vegetables and nonvegetable sources was calculated by use of a validated comprehensive database. Results After adjusting for age, sex, smoking, energy intake, fish consumption, and AMD risk alleles (complement factor H and age-related maculopathy susceptibility-2 single nucleotide polymorphisms), participants in the third quartile compared with those in the first quartile (reference group) of total nitrate and total vegetable nitrate intake had reduced risk of incident early AMD: odds ratio (OR) 0.61 (95% CI 0.41 to 0.90) and OR 0.65 (95% CI 0.44 to 0.96), respectively. Significant associations were not observed between the fourth vs first quartile of total nitrate and vegetable nitrate intake with incident early AMD: OR 0.74 (95% CI 0.51 to 1.08) and OR 0.69 (95% CI 0.47 to 1.00), respectively. Nonsignificant associations were also observed with 15-year incidence of late AMD and total nonvegetable nitrate intake. Conclusions These novel findings could have important implications, if the association between total nitrate intake and vegetable nitrate intake and 15-year incidence of early AMD is confirmed in other observational or intervention studies

    Dietary flavonoids and the prevalence and 15-y incidence of age-related macular degeneration

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    Background: The majority of research performed to date has examined the effects of commonly known antioxidants such as vitamins C, E, and A and carotenoids on age-related macular degeneration (AMD) risk and progression. To date, there is limited research on promising phytochemicals with antioxidant and anti-inflammatory properties, including flavonoids. Objective: In this exploratory study, we aimed to assess the independent associations between dietary intake of total flavonoids and common flavonoid classes with the prevalence and 15-y incidence of AMD. Design: In this population-based cohort study, 2856 adults aged ≥49 y at baseline and 2037 followed up 15 y later were included in prevalence and incidence analyses, respectively. Dietary intake was assessed by using a semiquantitative food-frequency questionnaire (FFQ). Estimates of the flavonoid content of foods in the FFQ were assessed by using the USDA Flavonoid, Isoflavone, and Proanthocyanidin databases. AMD was assessed from retinal photographs. Results: In cross-sectional analysis, each 1-SD increase in total overall flavonoid intake was associated with a reduced likelihood of any AMD (multivariable-adjusted OR: 0.76; 95% CI: 0.58, 0.99). Each 1-SD increase in dietary intake of total flavonols and total flavanones was associated with reduced odds of the prevalence of any AMD [multivariable-adjusted OR (95% CI): 0.75 (0.58, 0.97) and 0.77 (0.60, 0.99), respectively]. A marginally significant trend (P = 0.05) was observed between increasing the intake of total flavanone and hesperidin (from the first to the fourth quartile) and reduced likelihood of incident late AMD, after multivariable adjustment. Participants who reported ≥1 serving of oranges/d compared with those who never consumed oranges at baseline had a reduced risk of late AMD 15 y later (multivariable-adjusted OR: 0.39; 95% CI: 0.18, 0.85). Conclusions: Our findings suggest an independent and protective association between dietary intake of flavonoids and the likelihood of having AMD. Additional prospective cohort studies are needed to validate these findings

    A Deep Learning Model for Segmentation of Geographic Atrophy to Study Its Long-Term Natural History

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    __Purpose:__ To develop and validate a deep learning model for the automatic segmentation of geographic atrophy (GA) using color fundus images (CFIs) and its application to study the growth rate of GA. __Design:__ Prospective, multicenter, natural history study with up to 15 years of follow-up. __Participants:__ Four hundred nine CFIs of 238 eyes with GA from the Rotterdam Study (RS) and Blue Mountain Eye Study (BMES) for model development, and 3589 CFIs of 376 eyes from the Age-Related Eye Disease Study (AREDS) for analysis of GA growth rate. __Methods:__ A deep learning model based on an ensemble of encoder–decoder architectures was implemented and optimized for the segmentation of GA in CFIs. Four experienced graders delineated, in consensus, GA in CFIs from the RS and BMES. These manual delineations were used to evaluate the segmentation model using 5-fold cross-validation. The model was applied further to CFIs from the AREDS to study the growth rate of GA. Linear regression analysis was used to study associations between structural biomarkers at baseline and the GA growth rate. A general estimate of the progression of GA area over time was made by combining growth rates of all eyes with GA from the AREDS set. __Main Outcome Measures:__ Automatically segmented GA and GA growth rate. __Results:__ The model obtained an average Dice coefficient of 0.72±0.26 on the BMES and RS set while comparing the automatically segmented GA area with the graders’ manual delineations. An intraclass correlation coefficient of 0.83 was reached between the automatically estimated GA area and the graders’ consensus measures. Nine automatically calculated structural biomarkers (area, filled area, convex area, convex solidity, eccentricity, roundness, foveal involvement, perimeter, and circularity) were significantly associated with growth rate. Combining all growth rates indicated that GA area grows quadratically up to an area of approximately 12 mm2, after which growth rate stabilizes or decreases. __Conclusions:__ The deep learning model allowed for fully automatic and robust segmentation of GA on CFIs. These segmentations can be used to extract structural characteristics of GA that predict its growth rate

    Clinical and Epidemiologic Research Ethnic Variation in Early Age-Related Macular Degeneration Lesions Between White Australians and Singaporean Asians

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    Citation: Joachim N, Mitchell P, Younan C, et al. Ethnic variation in early age-related macular degeneration lesions between white Australians and Singaporean Asians. Invest Ophthalmol Vis Sci. 2014;55:4421-4429. DOI:10.1167/iovs.14-14476 PURPOSE. We compared early age-related macular degeneration (AMD) lesion characteristics between white Australians and Singaporean Asians. METHODS. Participants of the Blue Mountains Eye Study (BMES; whites, n ¼ 3508) and the Singapore Epidemiology of Eye Disease Study (SEED; Malay, n ¼ 3280, Indian, n ¼ 3400, and Chinese, n ¼ 3353) underwent examinations, including retinal photography. The AMD lesions were assessed following the Wisconsin AMD grading protocol by the same photographic grader. Prevalence and characteristics of early AMD lesions were compared between the BMES and the SEED. The associations between ethnicity and early AMD lesion types were analyzed using logistic regression models adjusting for age, sex, smoking status, lipids, and genetic polymorphisms associated with AMD. RESULTS. After age-standardization to the BMES population, the prevalence of distinct soft drusen was significantly higher in Singaporeans compared to Australians (23.9%, 95% confidence interval [CI] 22.9-25.0 vs. 6.2%, 95% CI 5.3-7.0), with an adjusted odds ratio (OR) of 4.6 (95% CI 3.4-6.0). In contrast, the prevalence of indistinct soft or reticular drusen was significantly lower in Singaporeans compared to Australians (6.5%, 95% CI 5.9-7.1 vs. 8.3%, 95% CI 7.4-9.3, with nonsignificant adjusted OR of 1.2, 95% CI 0.8-1.7). Soft drusen of any type were present frequently at the inner and outer macula (within a zone ‡500 to <3000 lm radius from the foveal center) among Singaporeans, while among Australians soft drusen were present more frequently at the central macula (<500 lm radius). CONCLUSIONS. Singaporean Asians had a milder spectrum of early AMD lesions and lesion characteristics (predominantly distinct soft drusen and noncentral location) compared to white Australians

    Intravitreal ranibizumab for neovascular age-related macular degeneration in clinical practice : five-year treatment outcomes

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    Background: Intravitreal anti-vascular endothelial growth factor (anti-VEGF) agents are the established standard of care for neovascular age-related macular degeneration (nAMD). However, data on long-term outcomes of this therapy are limited. The purpose of this study was to assess the visual and anatomical outcomes and safety profile of intravitreal ranibizumab in treating nAMD over a period of five years. Methods: 208 patients (208 eyes) were included in this retrospective case series study. Intervention was an "as-needed" treatment model. Visual acuity (VA), central macular thickness (CMT), ophthalmic examination, and adverse events (AEs) were assessed in each visit. Snellen VA was converted to Early Treatment Diabetic Retinopathy Study letters for analysis. Results: The average VA improved by 1.9 letters after one year (p = 0.017), and decreased by 2.4 letters over five years of treatment (p = 0.043). At the end of year five, 11.1 % of patients (23/208) had improved VA by more than 15 letters and 68.8 % (143/208) had VA improvement or loss less than or equal to 15 letters, while 20.2 % of patients (42/208) had a loss of more than 15 letters. Patients with VA of less than 35 letters at baseline showed significant VA improvement after five years of treatment. There was a positive relationship between injection numbers and VA improvement over the five-year period, after adjusting for age and baseline VA (p < 0.0005). Mean CMT decreased by 28.3 μm (p < 0.0005) over five years. Ocular AEs, serious adverse events (SAEs), and systemic SAEs occurred in 4.6 %, 0.48 %, and 2 % of patients, respectively, during the follow-up period. Conclusions: The use of intravitreal ranibizumab in an as-needed treatment regimen over a five-year period was effective in maintaining vision in patients with nAMD and in reducing macular thickness, with a relatively low rate of adverse and serious adverse events.9 page(s

    Enlargement of Geographic Atrophy from First Diagnosis to End of Life

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    Importance: Treatments for geographic atrophy (GA), a late stage of age-related macular degeneration (AMD), are currently under development. Understanding the natural course is needed for optimal trial design. Although enlargement rates of GA and visual acuity (VA) in the short term are known from clinical studies, knowledge of enlargement in the long term, life expectancy, and visual course is lacking. Objective: To determine long-term enlargement of GA. Design, Setting, and Participants: In this study, participant data were collected from 4 population-based cohort studies, with up to 25 years of follow-up and eye examinations at 5-year intervals: the Rotterdam Study cohorts 1, 2, and 3 and the Blue Mountains Eye Study. Data were collected from 1990 to 2015, and data were analyzed from January 2019 to November 2020. Main Outcomes and Measures: Area of GA was measured pixel by pixel using all available imaging. Area enlargement and enlargement of the square root-transformed area, time until GA reached the central fovea, and time until death were assessed, and best-corrected VA, smoking status, macular lesions according to the Three Continent AMD Consortium classification, a modified version of the Wisconsin age-related maculopathy grading system, and AMD genetic variants were covariates in Spearman, Pearson, or Mann-Whitney analyses. Results: Of 171 included patients, 106 (62.0%) were female, and the mean (SD) age at inclusion was 82.6 (7.1) years. A total of 147 of 242 eyes with GA (60.7%) were newly diagnosed in our study. The mean area of GA at first presentation was 3.74 mm2(95% CI, 3.11-4.67). Enlargement rate varied widely between persons (0.02 to 4.05 mm2per year), with a mean of 1.09 mm2per year (95% CI, 0.89-1.30). Stage of AMD in the other eye was correlated with GA enlargement (Spearman ρ = 0.34; P =.01). Foveal involvement was already present in incident GA in 55 of 147 eyes (37.4%); 23 of 42 eyes (55%) developed this after a mean (range) period of 5.6 (3-12) years, and foveal involvement did not develop before death in 11 of 42 eyes (26%). After first diagnosis, 121 of 171 patients with GA (70.8%) died after a mean (SD) period of 6.4 (5.4) years. Visual function was visually impaired (less than 20/63) in 47 of 107 patients (43.9%) at last visit before death. Conclusions and Relevance: In this study, enlargement of GA appeared to be highly variable in the general population. More than one-third of incident GA was foveal at first presentation; those with extrafoveal GA developed foveal GA after a mean of 5.6 years. Future intervention trials should focus on recruiting those patients who have a high chance of severe visual decline within their life expectancy.
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