Age-related Macular Degeneration

Age-related Macular Degeneration (AMD) Publications

Rodriguez JD, Wallstrom G, Narayanan D, Welch D, Abelson MB. An Alternative Psychophysical Diagnostic Indicator of the Aging Eye. J Ophthalmol 2019;2019:2036192.Abstract
Purpose: Impaired adaptation to changes in lighting levels as well as mesopic visual function is a common complaint in those over the age of 65. The use of photostress is a well-established method to test the adaption rate and the response of the visual cycle. In this study, we test visual function recovery to mesopic luminance stimuli following a long duration photostress in young and elderly subjects. If successful in strongly differentiating aging macular function, these methods may also be useful in the study of pathologies such as age-related macular degeneration. Methods: A group of 12 older normal subjects (mean age 75.1 ± 4.79) and a control group of 5 younger normal subjects (mean age 26.2 ± 4.19) were subjected to macular photostress using the OraLux photostress system. The OraLux system provides a diffuse light source bleaching 84% of cone photopigment while maintaining an exposure safety factor of 200 times less than the maximum safe exposure. After each photostressing session, macular recovery was tracked using a foveal, variable contrast, flickering stimulus of mean luminance in the high mesopic range. Recovery was tracked for 300 seconds. The endpoint was time to recovery to each individual's baseline sensitivity as determined by two static sensitivity trials prior to photostress. Results: Proportional hazards analysis of recovery time yielded a statistically significant difference between the older group and the young group (HR = 0.181; =0.0289). The estimated hazard ratio of 0.181 indicates that older subjects return to baseline at less than one-fifth the rate of younger subjects. The hazards ratio remained statistically significant after adjusting for visual acuity (HR = 0.093; =0.0424). Conclusion: Photostress recovery of flicker sensitivity under mesopic conditions is a strong differentiator of aging macular function. This agrees with subject-reported complaints in reduced luminance conditions after exposure to bright lights such as night driving. The qualitative similarity between the aging retina and changes in early AMD suggests that flicker recovery following photostress may be useful as a surrogate endpoint in AMD clinical trials.
Menon M, Mohammadi S, Davila-Velderrain J, Goods BA, Cadwell TD, Xing Y, Stemmer-Rachamimov A, Shalek AK, Love JC, Kellis M, Hafler BP. Single-cell transcriptomic atlas of the human retina identifies cell types associated with age-related macular degeneration. Nat Commun 2019;10(1):4902.Abstract
Genome-wide association studies (GWAS) have identified genetic variants associated with age-related macular degeneration (AMD), one of the leading causes of blindness in the elderly. However, it has been challenging to identify the cell types associated with AMD given the genetic complexity of the disease. Here we perform massively parallel single-cell RNA sequencing (scRNA-seq) of human retinas using two independent platforms, and report the first single-cell transcriptomic atlas of the human retina. Using a multi-resolution network-based analysis, we identify all major retinal cell types, and their corresponding gene expression signatures. Heterogeneity is observed within macroglia, suggesting that human retinal glia are more diverse than previously thought. Finally, GWAS-based enrichment analysis identifies glia, vascular cells, and cone photoreceptors to be associated with the risk of AMD. These data provide a detailed analysis of the human retina, and show how scRNA-seq can provide insight into cell types involved in complex, inflammatory genetic diseases.
Miller JW. Developing Therapies for Age-related Macular Degeneration: The Art and Science of Problem-solving: The 2018 Charles L. Schepens, MD, Lecture. Ophthalmol Retina 2019;3(10):900-909.Abstract
PURPOSE: To review the roles of analytic and innovative thought in advancing knowledge, using past examples in ophthalmology, and to explore potential strategies to improve our understanding of age-related macular degeneration (AMD) and develop new therapies. DESIGN: Presented as the 2018 Charles L. Schepens, MD, Lecture at the American Academy of Ophthalmology Retina Subspecialty Day, Chicago, Illinois, on October 26, 2018. PARTICIPANTS: None. METHODS: Review of published literature and sources on creativity and innovation. MAIN OUTCOME MEASURES: Recommendations for future AMD research. RESULTS: Innovative solutions to problems often seem intuitively obvious in hindsight. Yet, some problems seem impossible to solve. In the 1990s, AMD was a significant unmet need, with only destructive therapies for neovascular disease. This changed with the development of 2 therapies: (1) verteporfin photodynamic therapy (PDT) and (2) anti-vascular endothelial growth factor (VEGF) therapies, which are now administered to millions of people annually around the world. Now, we are frustrated by the lack of therapies for early and intermediate AMD and geographic atrophy. Photodynamic therapy and anti-VEGF drug development occurred through a combination of analytic thought and creative disruption through innovation. To get past our current impasse in understanding and treating AMD, we need to harness both analysis and innovation. We have many important building blocks in place-information on genetics, clinical findings, imaging, and histology-and have identified key pathways and potential therapeutic targets. Perhaps we need additional investigation, analysis, and integration to improve our understanding through work on structure/function and genotype/phenotype correlations and development of imaging and systemic biomarkers. We likely also need an innovative disruption. This innovation might be the concept that there are subtypes of early and intermediate AMD characterized by specific clinical phenotypes, genotype, functional characteristics, and biomarkers that are dependent on particular pathways and treatable with a specific agent. We need to encourage innovation in each of us within our research and clinical community. CONCLUSIONS: Although we have accumulated extensive knowledge about AMD, we are currently at an impasse in the development of new treatments. We need to continue the analytic process, but at the same time encourage innovative disruption to develop successful AMD therapies.
Handa JT, Bowes Rickman C, Dick AD, Gorin MB, Miller JW, Toth CA, Ueffing M, Zarbin M, Farrer LA. A systems biology approach towards understanding and treating non-neovascular age-related macular degeneration. Nat Commun 2019;10(1):3347.Abstract
Age-related macular degeneration (AMD) is the most common cause of blindness among the elderly in the developed world. While treatment is effective for the neovascular or "wet" form of AMD, no therapy is successful for the non-neovascular or "dry" form. Here we discuss the current knowledge on dry AMD pathobiology and propose future research directions that would expedite the development of new treatments. In our view, these should emphasize system biology approaches that integrate omic, pharmacological, and clinical data into mathematical models that can predict disease onset and progression, identify biomarkers, establish disease causing mechanisms, and monitor response to therapy.
Parikh R, Avery RL, Saroj N, Thompson D, Freund BK. Incidence of New Choroidal Neovascularization in Fellow Eyes of Patients With Age-Related Macular Degeneration Treated With Intravitreal Aflibercept or Ranibizumab. JAMA Ophthalmol 2019;Abstract
Importance: Incidence of conversion to neovascular age-related macular degeneration (nAMD) in untreated fellow eyes of patients who are treated for nAMD in 1 eye with anti-vascular endothelial growth factor agents provides important prognostic information to clinically manage patients. Objective: To investigate the association of treatment assignment (intravitreal aflibercept vs ranibizumab) and baseline characteristics with fellow eye conversion to nAMD in the VEGF (Vascular Endothelial Growth Factor) Trap-Eye: Investigation of Efficacy and Safety in Wet AMD (VIEW) studies. Design, Setting, and Participants: This post hoc analysis of the VIEW 1 and VIEW 2 studies (randomized, double-masked, active-controlled, multicenter, 96-week, phase 3 trials comparing the efficacy and safety of intravitreal aflibercept in 2457 patients with treatment-naive eyes with nAMD) analyzed a subgroup of participants treated for nAMD in 1 eye who had untreated fellow eyes without neovascularization at baseline. All participants in the VIEW studies were included in 1 of 4 groups: ranibizumab, 0.5 mg, every 4 weeks; aflibercept, 2 mg, every 4 weeks; aflibercept, 0.5 mg, every 4 weeks; or aflibercept, 2 mg, every 8 weeks after 3 injections at 4-week intervals. Data collection in the VIEW studies occurred from July 2007 to August 2011; the data analysis presented in this report took place from April 2016 to November 2018. Interventions: Patients received no treatment in the fellow eyes unless after conversion to nAMD, when any treatment approved by heath authorities was given per the investigators' discretion. Main Outcomes and Measures: Incidence of conversion to nAMD in patients with untreated fellow eyes that had not had clinical signs of neovascularization at baseline. Results: A total of 1561 participants were included in this analysis. At 96 weeks, 375 patients (24.0%) experienced cases of conversion to neovascular disease in the fellow eye, including 107 of the 399 individuals who received ranibizumab, 0.5 mg, every 4 weeks; 93 of the 387 individuals who received aflibercept, 2 mg, every 4 weeks; 84 of the 387 individuals who received aflibercept, 0.5 mg, every 4 weeks; and 91 of the 388 individuals who received aflibercept, 2 mg, every 8 weeks after 3 doses at 4-week intervals. The rates were 18.1, 16.2, 14.7, and 16.0 per 100 patient-years at risk at week 96, respectively. On multivariate analysis, fellow eye conversion was associated with increasing patient age (per 10 years) at baseline (hazard ratio [HR], 1.20 [95% CI, 1.05-1.36]), female sex (HR, 1.32 [95% CI, 1.06-1.63]), intraretinal fluid in the study eye at baseline (HR, 1.28 [95% CI, 1.02-1.61]), and increasing choroidal neovascularization lesion size (per 10 mm2) in the study eye at baseline (HR, 1.29 [95% CI, 1.06-1.57]). Rates of fellow eye conversion were similar with either of the treatments. Conclusions and Relevance: In this secondary analysis of randomized clinical trial data, patients with active nAMD in 1 eye appeared to have a high risk for fellow eye conversion. Such patients should be monitored closely.
Laíns I, Chung W, Kelly RS, Gil J, Marques M, Barreto P, Murta JN, Kim IK, Vavvas DG, Miller JB, Silva R, Lasky-Su J, Liang L, Miller JW, Husain D. Human Plasma Metabolomics in Age-Related Macular Degeneration: Meta-Analysis of Two Cohorts. Metabolites 2019;9(7)Abstract
The pathogenesis of age-related macular degeneration (AMD), a leading cause of blindness worldwide, remains only partially understood. This has led to the current lack of accessible and reliable biofluid biomarkers for diagnosis and prognosis, and absence of treatments for dry AMD. This study aimed to assess the plasma metabolomic profiles of AMD and its severity stages with the ultimate goal of contributing to addressing these needs. We recruited two cohorts: Boston, United States ( = 196) and Coimbra, Portugal ( = 295). Fasting blood samples were analyzed using ultra-high performance liquid chromatography mass spectrometry. For each cohort, we compared plasma metabolites of AMD patients versus controls (logistic regression), and across disease stages (permutation-based cumulative logistic regression considering both eyes). Meta-analyses were then used to combine results from the two cohorts. Our results revealed that 28 metabolites differed significantly between AMD patients versus controls (false discovery rate (FDR) -value: 4.1 × 10-1.8 × 10), and 67 across disease stages (FDR -value: 4.5 × 10-1.7 × 10). Pathway analysis showed significant enrichment of glycerophospholipid, purine, taurine and hypotaurine, and nitrogen metabolism (-value ≤ 0.04). In conclusion, our findings support that AMD patients present distinct plasma metabolomic profiles, which vary with disease severity. This work contributes to the understanding of AMD pathophysiology, and can be the basis of future biomarkers and precision medicine for this blinding condition.
Papadopoulos Z. Aflibercept: A review of its effect on the treatment of exudative age-related macular degeneration. Eur J Ophthalmol 2019;29(4):368-378.Abstract
Considerable improvement has been achieved in the way in which exudative age-related macular degeneration is conventionally treated and in the associated visual outcomes and prognosis, thanks to the agents with effects against vascular endothelial growth factor (anti-VEGF). By comparison to earlier treatment approaches that involved the use of lasers, the anti-VEGF agents have made it possible to accomplish more positive visual and anatomical outcomes in cases of exudative age-related macular degeneration. Indeed, owing to their positive effects, anti-VEGF agents have quickly come to be considered the gold standard for the treatment of wet age-related macular degeneration. Aflibercept, the most recently approved intravitreally administered anti-VEGF, seems to mark another milestone in the treatment of wet age-related macular degeneration. This anti-VEGF agent presents a series of singular pharmacodynamic and pharmacokinetic attributes that provide it a number of biological benefits in relation to the treatment of choroidal neovascularization compared to other agents. These attributes include high level of affinity for the VEGF-A factor, an intravitreal half-life of great length, as well as the ability to serve as an antagonist for other growth factors besides VEGF. The impact of Aflibercept on the manner in which exudative age-related macular degeneration is managed was demonstrated by thoroughly reviewing the related literature. The present review article highlights the pharmacology, pharmacokinetics, safety and effectiveness of this anti-VEGF agent as well as the landmark clinical studies that have been carried out to establish this drug as a gold standard in the therapy of neovascular age-related macular degeneration. In addition, studies regarding the outcomes and effectiveness of the various dosage regimens, either as monotherapy or in combination with other agents, are also reviewed.
McHugh KJ, Li D, Wang JC, Kwark L, Loo J, Macha V, Farsiu S, Kim LA, Saint-Geniez M. Computational modeling of retinal hypoxia and photoreceptor degeneration in patients with age-related macular degeneration. PLoS One 2019;14(6):e0216215.Abstract
Although drusen have long been acknowledged as a primary hallmark of dry age-related macular degeneration (AMD) their role in the disease remains unclear. We hypothesize that drusen accumulation increases the barrier to metabolite transport ultimately resulting in photoreceptor cell death. To investigate this hypothesis, a computational model was developed to evaluate steady-state oxygen distribution in the retina. Optical coherence tomography images from fifteen AMD patients and six control subjects were segmented and translated into 3D in silico representations of retinal morphology. A finite element model was then used to determine the steady-state oxygen distribution throughout the retina for both generic and patient-specific retinal morphology. Oxygen levels were compared to the change in retinal thickness at a later time point to observe possible correlations. The generic finite element model of oxygen concentration in the retina agreed closely with both experimental measurements from literature and clinical observations, including the minimal pathological drusen size identified by AREDS (64 μm). Modeling oxygen distribution in the outer retina of AMD patients showed a substantially stronger correlation between hypoxia and future retinal thinning (Pearson correlation coefficient, r = 0.2162) than between drusen height and retinal thinning (r = 0.0303) indicating the potential value of this physiology-based approach. This study presents proof-of-concept for the potential utility of finite element modeling in evaluating retinal health and also suggests a potential link between transport and AMD pathogenesis. This strategy may prove useful as a prognostic tool for predicting the clinical risk of AMD progression.
Rong SS, Lee BY, Kuk AK, Yu XT, Li SS, Li J, Guo Y, Yin Y, Osterbur DL, Yam JCS, Cheung CY, Chen LJ, Wong TY, Ng DS-C. Comorbidity of dementia and age-related macular degeneration calls for clinical awareness: a meta-analysis. Br J Ophthalmol 2019;Abstract
AIM: To determine the association between dementia and age-related macular degeneration (AMD) using meta-analysis. METHODS: We searched in the MEDLINE, EMBASE, Web of Knowledge, PsycInfo and Cochrane database of systematic reviews for studies published from March 1959 to March 2018. We included cross-sectional, case-control and cohort studies that evaluated the association of dementia/Alzheimer's disease (AD) with AMD (as outcome) and the association of AMD with dementia/AD (as outcome). Studies that compared cognitive functions between AMD and controls were also included. The summary outcomes, namely odds ratio (OR), relative risk, mean differences and corresponding 95% CIs, were estimated using random effects models. We performed sensitivity analysis based on study quality and individual study effect to control for potential biases. RESULTS: Among 2159 citation records, we identified 21 studies consisting of 7 876 499 study subjects for meta-analysis. Patients with dementia (p≤0.017, OR≥1.24, I≤9%) or AD (p=0.001, OR=2.22, I=50%) were at risk for AMD, particularly for late AMD (p<0.001, OR=1.37, I=0). AMD was also significantly associated with increased risk of AD/cognitive impairment (p=0.037, OR=2.42, I=38%). Moreover, patients with AMD had poorer cognitive functions when compared with controls, including Mini-Mental State Examination (p<0.001, I≤79%) and Trail Making Test A (p<0.001, I=0). Sensitivity analysis and Egger's test indicated our results were less likely biased. CONCLUSIONS: A significant association between dementia/AD and AMD calls for greater clinical awareness. The cost-effectiveness of routine screening for the other condition in patients with primary diagnosis of dementia/AD or AMD requires further study.
Owen LA, Shakoor A, Morgan DJ, Hejazi AA, McEntire WM, Brown JJ, Farrer LA, Kim I, Vitale A, Deangelis MM. The Utah Protocol for Postmortem Eye Phenotyping and Molecular Biochemical Analysis. Invest Ophthalmol Vis Sci 2019;60(4):1204-1212.Abstract
Purpose: Current understanding of local disease pathophysiology in AMD is limited. Analysis of the human disease-affected tissue is most informative, as gene expression, expressed quantitative trait loci, microenvironmental, and epigenetic changes can be tissue, cell type, and location specific. Development of a novel translational treatment and prevention strategies particularly for earlier forms of AMD are needed, although access to human ocular tissue analysis is challenging. We present a standardized protocol to study rapidly processed postmortem donor eyes for molecular biochemical and genomic studies. Methods: We partnered with the Utah Lions Eye Bank to obtain donor human eyes, blood, and vitreous, within 6 hours postmortem. Phenotypic analysis was performed using spectral-domain optical coherence tomography (SD-OCT) and color fundus photography. Macular and extramacular tissues were immediately isolated, and the neural retina and retinal pigment epithelium/choroid from each specimen were separated and preserved. Ocular disease phenotype was analyzed using clinically relevant grading criteria by a group of four ophthalmologists incorporating data from SD-OCT retinal images, fundus photographs, and medical records. Results: The use of multimodal imaging leads to greater resolution of retinal pathology, allowing greater phenotypic rigor for both interobserver phenotype and known clinical diagnoses. Further, our analysis resulted in excellent quality RNA, which demonstrated appropriate tissue segregation. Conclusions: The Utah protocol is a standardized methodology for analysis of disease mechanisms in AMD. It uniquely allows for simultaneous rigorous phenotypic, molecular biochemical, and genomic analysis of both systemic and local tissues. This better enables the development of disease biomarkers and therapeutic interventions.
Farinha CVL, Cachulo ML, Alves D, Pires I, Marques JP, Barreto P, Nunes S, Costa J, Martins A, Sobral I, Laíns I, Figueira J, Ribeiro L, Cunha-Vaz J, Silva R. Incidence of Age-Related Macular Degeneration in the Central Region of Portugal: The Coimbra Eye Study - Report 5. Ophthalmic Res 2019;:1-10.Abstract
PURPOSE: To describe the 6.5-year incidence and progression of age-related macular degeneration (AMD) in a coastal town of central Portugal. METHODS: Population-based cohort study. Participants underwent standardized interviews and ophthalmological examination. Color fundus photographs were graded according to the International Classification and Grading System for AMD and ARM. The crude and age-standardized incidence of early and late AMD was calculated, and progression was analyzed. RESULTS: The 6.5-year cumulative incidence of early AMD was 10.7%, and of late AMD it was 0.8%. The incidence of early AMD was 7.2, 13.1 and 17.7% for participants aged 55-64, 65-74 and 75-84 years (p < 0.001). The late AMD incidence was 0.3, 0.9 and 2.8% for the corresponding age groups (p = 0.003). The age-standardized incidence was 10.8% (95% CI, 10.74-10.80%) for early and 1.0% (95% CI, 1.00-1.02%) for late AMD. The incidence of both neovascular AMD and geographic atrophy was 0.4%. Progression occurred in 17.2% of patients. CONCLUSION: The early AMD incidence in a coastal town of central Portugal was found to be similar to that of major epidemiological studies of European-descent populations; however, the incidence of late AMD was lower, and further analysis on risk factors will be conducted.
Wang Y, Liu C-H, Ji T, Mehta M, Wang W, Marino E, Chen J, Kohane DS. Intravenous treatment of choroidal neovascularization by photo-targeted nanoparticles. Nat Commun 2019;10(1):804.Abstract
Choroidal neovascularization (CNV) is the major cause of vision loss in wet age-related macular degeneration (AMD). Current therapies require repeated intravitreal injections, which are painful and can cause infection, bleeding, and retinal detachment. Here we develop nanoparticles (NP-[CPP]) that can be administered intravenously and allow local drug delivery to the diseased choroid via light-triggered targeting. NP-[CPP] is formed by PEG-PLA chains modified with a cell penetrating peptide (CPP). Attachment of a DEACM photocleavable group to the CPP inhibits cellular uptake of NP-[CPP]. Irradiation with blue light cleaves DEACM from the CPP, allowing the CPP to migrate from the NP core to the surface, rendering it active. In mice with laser-induced CNV, intravenous injection of NP-[CPP] coupled to irradiation of the eye allows NP accumulation in the neovascular lesions. When loaded with doxorubicin, irradiated NP-[CPP] significantly reduces neovascular lesion size. We propose a strategy for non-invasive treatment of CNV and enhanced drug accumulation specifically in diseased areas of the eye.
Roh M, Laíns I, Shin HJ, Park DH, Mach S, Vavvas DG, Kim IK, Miller JW, Husain D, Miller JB. Microperimetry in age-related macular degeneration: association with macular morphology assessed by optical coherence tomography. Br J Ophthalmol 2019;Abstract
BACKGROUND/AIMS: Microperimetry is a technique that is increasingly used to assess visual function in age-related macular degeneration (AMD). In this study, we aimed to evaluate the relationship between retinal sensitivity measured with macular integrity assessment (MAIA) microperimetry and optical coherence tomography (OCT)-based macular morphology in AMD. METHODS: Prospective, cross-sectional study. All participants were imaged with colour fundus photographs used for AMD staging (Age-Related Eye Disease Study scale), spectral-domain OCT (Spectralis, Heidelberg, Germany) and swept-source OCT (Topcon, Japan). Threshold retinal sensitivity of the central 10° diameter circle was assessed with the full-threshold, 37-point protocol of the MAIA microperimetry device (Centervue, Italy). Univariable and multivariable multilevel mixed-effect linear regression models were used for analysis. RESULTS: We included 102 eyes with AMD and 46 control eyes. Multivariable analysis revealed that older age (p<0.0001), advanced AMD stage (p<0.0001) and reduced retinal thickness (p<0.0001) were associated with decreased mean retinal sensitivity. No associations were found between choroidal thickness and retinal sensitivity within the macula. Within the 10° diameter circle of the macula, the presence of ellipsoid disruption, subretinal fluid, atrophy and fibrosis, and outer retinal tubulation on OCT images was also associated with decreased retinal sensitivity (all p<0.05). CONCLUSIONS: There is an association between TRS as determined by MAIA microperimetry and several OCT structural parameters across various stages of AMD. This study highlights the relevance of microperimetry as a functional outcome measure for AMD.
Laíns I, Duarte D, Barros AS, Martins AS, Carneiro TJ, Gil JQ, Miller JB, Marques M, Mesquita TS, Barreto P, Kim IK, da Luz Cachulo M, Vavvas DG, Carreira IM, Murta JN, Silva R, Miller JW, Husain D, Gil AM. Urine Nuclear Magnetic Resonance (NMR) Metabolomics in Age-Related Macular Degeneration. J Proteome Res 2019;18(3):1278-1288.Abstract
Biofluid biomarkers of age-related macular degeneration (AMD) are still lacking, and their identification is challenging. Metabolomics is well-suited to address this need, and urine is a valuable accessible biofluid. This study aimed to characterize the urinary metabolomic signatures of patients with different stages of AMD and a control group (>50 years). It was a prospective, cross-sectional study, where subjects from two cohorts were included: 305 from Coimbra, Portugal (AMD patients n = 252; controls n = 53) and 194 from Boston, United States (AMD patients n = 147; controls n = 47). For all participants, we obtained color fundus photographs (for AMD staging) and fasting urine samples, which were analyzed using H nuclear magnetic resonance (NMR) spectroscopy. Our results revealed that in both cohorts, urinary metabolomic profiles differed mostly between controls and late AMD patients, but important differences were also found between controls and subjects with early AMD. Analysis of the metabolites responsible for these separations revealed that, even though distinct features were observed for each cohort, AMD was in general associated with depletion of excreted citrate and selected amino acids at some stage of the disease, suggesting enhanced energy requirements. In conclusion, NMR metabolomics enabled the identification of urinary signals of AMD and its severity stages, which might represent potential metabolomic biomarkers of the disease.

Pages