Proteomic Profiles in Advanced Age-Related Macular Degeneration Using an Aptamer-Based Proteomic Technology

Sigma-2 receptor modulator CT1812 alters key pathways and rescues retinal pigment epithelium (RPE) functional deficits associated with dry age-related macular degeneration (AMD)

Trafficking defects in retinal pigmented epithelial (RPE) cells contribute to RPE atrophy, a hallmark of geographic atrophy (GA) in dry age-related macular degeneration (AMD). Dry AMD pathogenesis is multifactorial, including amyloid-β (Aβ) accumulation and oxidative stress-common features of Alzheimer's disease (AD). The Sigma-2 receptor (S2R) regulates lipid and protein trafficking, and S2R modulators reverse trafficking deficits in neurodegeneration in vitro models. Given overlapping mechanisms contributing to AD and AMD, S2R modulator effects on RPE function were investigated. The S2R modulator CT1812 is in clinical trials for AD, dementia with Lewy bodies, and GA. Leveraging AD trials testing CT1812, unbiased analyses of patient biofluid proteomes revealed that proteins altered by CT1812 associated with GA and macular degeneration disease ontologies and overlapped with proteins altered in dry AMD. Differential expression analysis of RPE transcripts from APP-Swedish/London mutant transgenic mice, a model featuring Aβ accumulation, revealed reversal of autophagy/trafficking transcripts in S2R modulator-treated animals versus vehicle toward healthy control levels. Photoreceptor outer segment (POS) trafficking in human RPE cells showed deficits in response to Aβ1-42 or hydrogen peroxide compared to vehicle. S2R modulators normalized stressor-induced POS trafficking deficits, resembling healthy control. Taken together, S2R modulation may provide a novel therapeutic strategy for dry AMD.

Applications of artificial intelligence and bioinformatics methodologies in the analysis of ocular biofluid markers: a scoping review

PURPOSE

This scoping review summarizes the applications of artificial intelligence (AI) and bioinformatics methodologies in analysis of ocular biofluid markers. The secondary objective was to explore supervised and unsupervised AI techniques and their predictive accuracies. We also evaluate the integration of bioinformatics with AI tools.

METHODS

This scoping review was conducted across five electronic databases including EMBASE, Medline, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Web of Science from inception to July 14, 2021. Studies pertaining to biofluid marker analysis using AI or bioinformatics were included.

RESULTS

A total of 10,262 articles were retrieved from all databases and 177 studies met the inclusion criteria. The most commonly studied ocular diseases were diabetic eye diseases, with 50 papers (28%), while glaucoma was explored in 25 studies (14%), age-related macular degeneration in 20 (11%), dry eye disease in 10 (6%), and uveitis in 9 (5%). Supervised learning was used in 91 papers (51%), unsupervised AI in 83 (46%), and bioinformatics in 85 (48%). Ninety-eight papers (55%) used more than one class of AI (e.g. > 1 of supervised, unsupervised, bioinformatics, or statistical techniques), while 79 (45%) used only one. Supervised learning techniques were often used to predict disease status or prognosis, and demonstrated strong accuracy. Unsupervised AI algorithms were used to bolster the accuracy of other algorithms, identify molecularly distinct subgroups, or cluster cases into distinct subgroups that are useful for prediction of the disease course. Finally, bioinformatic tools were used to translate complex biomarker profiles or findings into interpretable data.

CONCLUSION

AI analysis of biofluid markers displayed diagnostic accuracy, provided insight into mechanisms of molecular etiologies, and had the ability to provide individualized targeted therapeutic treatment for patients. Given the progression of AI towards use in both research and the clinic, ophthalmologists should be broadly aware of the commonly used algorithms and their applications. Future research may be aimed at validating algorithms and integrating them in clinical practice.

Elevated tumor necrosis factor alpha and vascular endothelial growth factor in intermediate age-related macular degeneration and geographic atrophy

Introduction

Tumor necrosis factor alpha (TNF-α) is an inflammatory cytokine implicated in pathological changes to the retinal pigment epithelium that are similar to changes in geographic atrophy (GA), an advanced form of age related macular degeneration (AMD). TNF-α also modulates expression of other cytokines including vascular endothelial growth factor (VEGF), leading to choroidal atrophy in models of AMD. The purpose of this study was to investigate systemic TNF-α and VEGF in patients with GA and intermediate AMD (iAMD) compared to controls without AMD.

Methods

We examined plasma levels of TNF-α and VEGF in patients with GA, iAMD, and controls without AMD from the University of Colorado AMD registry (2014 to 2021). Cases and controls were characterized by multimodal imaging. TNF-α and VEGF were measured via multiplex immunoassay and data were analyzed using a non-parametric rank based linear regression model fit to plasma biomarkers.

Results

There were 97 GA, 199 iAMD patients and 139 controls. TNF-α was significantly increased in GA (Median:9.9pg/ml, IQR:7.3-11.8) compared to iAMD (Median:7.4, IQR:5.3-9.1) and in both GA and iAMD compared to controls (Median:6.4, IQR:5.3-7.8), p<0.01 for all comparisons. VEGF was significantly increased in iAMD (Median:8.9, IQR:4.8-14.3) compared to controls (Median:7.7, IQR:4.6-11.1), p<0.01. There was a significant positive correlation between TNF-α and VEGF in GA (0.46, p<0.01), and iAMD (0.20, p=0.01) with no significant interaction between TNF-α and VEGF in any group.

Discussion

These findings suggest TNF-α and VEGF may contribute to systemic inflammatory processes associated with iAMD and GA. TNF-α and VEGF may function as systemic biomarkers for disease development.

Discovery of Aptamers and the Acceleration of the Development of Targeting Research in Ophthalmology

Aptamers are widely applied to diagnosis and therapy because of their targeting. However, the current progress of research into aptamers for the treatment of eye disorders has not been well-documented. The current literature on aptamers was reviewed in this study. Aptamer-related drugs and biochemical sensors have been evaluated for several eye disorders within the past decade; S58 targeting TGF-β receptor II and pegaptanib targeting vascular endothelial growth factor (VEGF) are used to prevent fibrosis after glaucoma filtration surgery. Anti-brain-derived neurotrophic factor aptamer has been used to diagnose glaucoma. The first approved aptamer drug (pegaptanib) has been used to inhibit angiogenesis in age-related macular degeneration (AMD) and diabetic retinopathy (DR), and its efficacy and safety have been demonstrated in clinical trials. Aptamers, including E10030, RBM-007, AS1411, and avacincaptad pegol, targeting other angiogenesis-related biomarkers have also been discovered and subjected to clinical trials. Aptamers, such as C promoter binding factor 1, CD44, and advanced end products in AMD and DR, targeting other signal pathway proteins have also been discovered for therapy, and biochemical sensors for early diagnosis have been developed based on aptamers targeting VEGF, connective tissue growth factor, and lipocalin 1. Aptamers used for early detection and treatment of ocular tumors were derived from other disease biomarkers, such as CD71, nucleolin, and high mobility group A. In this review, the development and application of aptamers in eye disorders in recent years are systematically discussed, which may inspire a new link between aptamers and eye disorders. The aptamer development trajectory also facilitates the discovery of the pathogenesis and therapeutic strategies for various eye disorders.

Systemic Blood Proteome Patterns Reflect Disease Phenotypes in Neovascular Age-Related Macular Degeneration

There is early evidence of extraocular systemic signals effecting function and morphology in neovascular age-related macular degeneration (nAMD). The prospective, cross-sectional BIOMAC study is an explorative investigation of peripheral blood proteome profiles and matched clinical features to uncover systemic determinacy in nAMD under anti-vascular endothelial growth factor intravitreal therapy (anti-VEGF IVT). It includes 46 nAMD patients stratified by the level of disease control under ongoing anti-VEGF treatment. Proteomic profiles in peripheral blood samples of every patient were detected with LC-MS/MS mass spectrometry. The patients underwent extensive clinical examination with a focus on macular function and morphology. In silico analysis includes unbiased dimensionality reduction and clustering, a subsequent annotation of clinical features, and non-linear models for recognition of underlying patterns. The model assessment was performed using leave-one-out cross validation. The findings provide an exploratory demonstration of the link between systemic proteomic signals and macular disease pattern using and validating non-linear classification models. Three main results were obtained: (1) Proteome-based clustering identifies two distinct patient subclusters with the smaller one (n = 10) exhibiting a strong signature for oxidative stress response. Matching the relevant meta-features on the individual patient's level identifies pulmonary dysfunction as an underlying health condition in these patients. (2) We identify biomarkers for nAMD disease features with Aldolase C as a putative factor associated with superior disease control under ongoing anti-VEGF treatment. (3) Apart from this, isolated protein markers are only weakly correlated with nAMD disease expression. In contrast, applying a non-linear classification model identifies complex molecular patterns hidden in a high number of proteomic dimensions determining macular disease expression. In conclusion, so far unconsidered systemic signals in the peripheral blood proteome contribute to the clinically observed phenotype of nAMD, which should be examined in future translational research on AMD.

RANTES (CCL5) in Patients With Geographic Atrophy Age-Related Macular Degeneration

Purpose

A previous study from our research group showed significantly lower levels of RANTES (Regulated upon Activation, Normal T Cell Expressed and Secreted) in patients with intermediate age-related macular degeneration (AMD) compared to control patients with no AMD. The primary aim of this study was to assess levels of RANTES in a cohort of patients with a more advanced form of the disease, geographic atrophy (GA), in comparison with controls.

Methods

The study was conducted on a cohort of patients with GA recruited into a Colorado AMD registry. Cases and controls were defined with multimodal imaging. Plasma levels of the chemokine RANTES were measured using a multiplex assay. A nonparametric (rank-based) regression model was fit to RANTES with a sex by AMD category interaction.

Results

The plasma levels of RANTES were significantly higher in the control group in comparison to the GA AMD group (median [interquartile range]): 10,204 [5799-19,554] pg/mL vs. 5435 [3420-9177] pg/mL, respectively, P < 0.01). When moderated by sex, there was no statistical difference between the male and female GA AMD or the male and female controls.

Conclusions

We found lower level of RANTES in patients with GA AMD compared with controls. This finding is consistent with the findings from our previous intermediate AMD study. However, in contrast to the results of our previous research, when moderated by sex there was no statistical difference between male and female GA patients.

Translational Relevance

The biomarker RANTES is significantly lower in GA AMD patients compared to controls.

Recent Advances in Proteomics-Based Approaches to Studying Age-Related Macular Degeneration: A Systematic Review

Age-related macular degeneration (AMD) is a common ocular disease characterized by degeneration of the central area of the retina in the elderly population. Progression and response to treatment are influenced by genetic and non-genetic factors. Proteomics is a powerful tool to study, at the molecular level, the mechanisms underlying the progression of the disease, to identify new therapeutic targets and to establish biomarkers to monitor progression and treatment effectiveness. In this work, we systematically review the use of proteomics-based approaches for the study of the molecular mechanisms underlying the development of AMD, as well as the progression of the disease and on-treatment patient monitoring. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) reporting guidelines were followed. Proteomic approaches have identified key players in the onset of the disease, such as complement components and proteins involved in lipid metabolism and oxidative stress, but also in the progression to advanced stages, including factors related to extracellular matrix integrity and angiogenesis. Although anti-vascular endothelial growth factor (anti-VEGF)-based therapy has been crucial in the treatment of neovascular AMD, it is necessary to deepen our understanding of the underlying disease mechanisms to move forward to next-generation therapies for later-stage forms of this multifactorial disease.

Artificial Intelligence Analysis of Biofluid Markers in Age-Related Macular Degeneration: A Systematic Review

This systematic review explores the use of artificial intelligence (AI) in the analysis of biofluid markers in age-related macular degeneration (AMD). We detail the accuracy and validity of AI in diagnostic and prognostic models and biofluid markers that provide insight into AMD pathogenesis and progression. This review was conducted in accordance with the Preferred Reporting Items for a Systematic Review and Meta-analysis guidelines. A comprehensive search was conducted across 5 electronic databases including Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, EMBASE, Medline, and Web of Science from inception to July 14, 2021. Studies pertaining to biofluid marker analysis using AI or bioinformatics in AMD were included. Identified studies were assessed for risk of bias and critically appraised using the Joanna Briggs Institute Critical Appraisal tools. A total of 10,264 articles were retrieved from all databases and 37 studies met the inclusion criteria, including 15 cross-sectional studies, 15 prospective cohort studies, five retrospective cohort studies, one randomized controlled trial, and one case–control study. The majority of studies had a general focus on AMD (58%), while neovascular AMD (nAMD) was the focus in 11 studies (30%), and geographic atrophy (GA) was highlighted by three studies. Fifteen studies examined disease characteristics, 15 studied risk factors, and seven guided treatment decisions. Altered lipid metabolism (HDL-cholesterol, total serum triglycerides), inflammation (c-reactive protein), oxidative stress, and protein digestion were implicated in AMD development and progression. AI tools were able to both accurately differentiate controls and AMD patients with accuracies as high as 87% and predict responsiveness to anti-VEGF therapy in nAMD patients. Use of AI models such as discriminant analysis could inform prognostic and diagnostic decision-making in a clinical setting. The identified pathways provide opportunity for future studies of AMD development and could be valuable in the advancement of novel treatments.

A proteogenomic signature of age-related macular degeneration in blood

Age-related macular degeneration (AMD) is one of the most common causes of visual impairment in the elderly, with a complex and still poorly understood etiology. Whole-genome association studies have discovered 34 genomic regions associated with AMD. However, the genes and cognate proteins that mediate the risk, are largely unknown. In the current study, we integrate levels of 4782 human serum proteins with all genetic risk loci for AMD in a large population-based study of the elderly, revealing many proteins and pathways linked to the disease. Serum proteins are also found to reflect AMD severity independent of genetics and predict progression from early to advanced AMD after five years in this population. A two-sample Mendelian randomization study identifies several proteins that are causally related to the disease and are directionally consistent with the observational estimates. In this work, we present a robust and unique framework for elucidating the pathobiology of AMD.

Sex and Age-Related Differences in Complement Factors Among Patients With Intermediate Age-Related Macular Degeneration

Purpose

Age-related macular degeneration (AMD) is an acquired degenerative disease of the retina classified into early, intermediate, and advanced AMD. A key factor in the pathogenesis of AMD is the complement system. The interaction of age and sex with the complement system may affect the risk of developing AMD. The purpose of this study was to determine if there were sex-specific differences in levels of complement factors among patients with the intermediate phenotype of AMD (iAMD) and explore the correlation between age and complement proteins.

Methods

We studied complement factors in patients with iAMD and controls without AMD. Nonparametric, rank-based linear regressions including a sex by AMD interaction were used to compare levels for each analyte. Correlations between age and complement proteins were evaluated using the Spearman rank correlation coefficient.

Results

We found significantly higher levels of factor B and factor I in females compared with males with iAMD, whereas no differences were seen in complement levels in male and female controls. The ratios of Ba/factor B, C3a/C3, C4b/C4, and C5a/C5 were not different in males and females with iAMD.

Conclusions

We demonstrate disparities in a subset of systemic complement factors between females and males with iAMD, but apparent complement turnover as measured by ratios of activation fragments to intact molecules was not different between these groups. The results suggest that complement system levels, including complement regulator factor I, exhibits sex-related differences in patients with iAMD and highlights that stratification by sex might be helpful in the interpretation of clinical trials of anticomplement therapy.

Association of Systemic Inflammatory Factors with Progression to Advanced Age-related Macular Degeneration

PURPOSE

Age-related macular degeneration (AMD) is a leading cause of vision loss in the elderly. The role of systemic inflammation in AMD remains unclear specifically in patients with intermediate AMD (iAMD). We sought to determine whether systemic inflammation was associated with future iAMD progression.

METHODS

Combinations of 27 circulating inflammatory markers including complement factors, cytokines, chemokines, and high-sensitivity C-reactive protein (hsCRP) were evaluated in iAMD patients recruited into a Colorado AMD registry. Systemic inflammatory markers were combined using principal component analysis. Risk factors for AMD progression were evaluated using Cox regression models.

RESULTS

This study included 99 subjects with iAMD, 21 of which progressed to advanced AMD. Two principal components (PCs) were identified that contributed to the risk of progression to advanced AMD, after adjusting for age and bilateral reticular pseudodrusen. The strongest associated PC was explained largely by the pro-inflammatory cytokine TNFα and the anti-inflammatory IL1ra antagonist of IL1. The additional PC was largely explained by IL6, IL8, C3 and factor D in the positive direction and CRP, MCP1, factor B and factor I in the negative direction.

CONCLUSION

When evaluated through multivariate analyses, combinations of biomarkers distinguished patients who did and did not progress to future advanced AMD. Increased risk could result from different combinations of analyte levels indicating a complex relationship rather than a simple increase in a few markers. This suggests that studying systemic inflammation in iAMD can provide insights into early pathologic events and potentially identify patients at highest risk for the development of severe AMD.

Sex Differences in RANTES (CCL5) in Patients With Intermediate Age-Related Macular Degeneration (AMD) and Controls With no AMD

Purpose

To determine if there are sex differences in levels of regulated upon activation, normal T cell expressed and secreted (RANTES) in patients with intermediate age-related macular degeneration (iAMD) and in controls with no AMD.

Methods

Patients with iAMD and controls defined by multi-modal imaging were recruited into a Colorado AMD registry. Plasma levels of the chemokine RANTES were measured using a multiplex assay. A nonparametric (rank-based) regression model was fit to RANTES with a sex by AMD category interaction.

Results

The plasma level of RANTES was significantly higher in the control group in comparison with the iAMD group. When moderated by sex, RANTES was significantly lower (P = 0.005) in males (median, 4525.6 pg/mL; interquartile range, 2589–7861 pg/mL) compared with females (median, 6686 pg/mL; interquartile range, 3485–12488 pg/mL) within the iAMD cohort. No significant difference was found in levels of RANTES between males and females in the control group.

Conclusions

We found that levels of RANTES were moderated by sex in cases with iAMD with lower levels in males compared with females. The findings illustrate the importance of including sex as a biological variable in AMD research. There is a need for further studies of RANTES, stratified by sex, in the advanced phenotypes of AMD.

Translational Relevance

The biomarker RANTES identified in the plasma of patients with iAMD reflects systemic alterations when stratified by sex.

Novel Possible Protein Targets in Neovascular Age-Related Macular Degeneration: A Pilot Study Experiment

Age-related macular degeneration (AMD) is among the world's leading causes of blindness. In its neovascular form (nAMD), around 25% of patients present further anatomical and visual deterioration due to persistence of neovascular activity, despite gold-standard treatment protocols using intravitreal anti-VEGF medications. Thus, to comprehend, the molecular pathways that drive choroidal neoangiogenesis, associated with the vascular endothelial growth factor (VEGF), are important steps to elucidate the mechanistic events underneath the disease development. This is a pilot study, a prospective, translational experiment, in a real-life context aiming to evaluate the protein profiles of the aqueous humor of 15 patients divided into three groups: group 1, composed of patients with nAMD, who demonstrated a good response to anti-VEGF intravitreal injections during follow-up (good responsive); group 2, composed of patients with anti-VEGF-resistant nAMD, who demonstrated choroidal neovascularization activity during follow-up (poor/non-responsive); and group 3, composed of control patients without systemic diseases or signs of retinopathy. For proteomic characterization of the groups, mass spectrometry (label-free LC-MS/MS) was used. A total of 2,336 proteins were identified, of which 185 were distinctly regulated and allowed the differentiation of the clinical conditions analyzed. Among those, 39 proteins, including some novel ones, were analyzed as potential disease effectors through their pathophysiological implications in lipid metabolism, oxidative stress, complement system, inflammatory pathways, and angiogenesis. So, this study suggests the participation of other promising biomarkers in neovascular AMD, in addition to the known VEGF.

Plasma C-C Chemokine Concentrations in Intermediate Age-Related Macular Degeneration

Purpose: To determine the relationship between plasma concentrations of the C-C chemokines CCL2, CCL3, CCL4, and CCL5 and intermediate age-related macular degeneration (iAMD) patients compared with control inidividuals to further define the inflammatory pathways associated with age-related macular degeneration.

Methods: The concentrations of CCL2, CCL3, CCL4, and CCL5 were measured using multiplex assays in plasma collected from 210 patients with iAMD and 102 control individuals with no macular degeneration as defined by multi-modal imaging. Non-inflammatory data included in the analysis were: age, sex, family history of AMD, history of smoking, body mass index, presence of reticular pseudo-drusen and cardiovascular disease. Median concentrations as well as a cutoff value for each chemokine were compared between the two groups.

Results: The median concentrations of CCL2 and CCL4 did not differ between control and iAMD groups, however, CCL2 was elevated in iAMD when a cutoff comparison was used (p < 0.05). Median CCL3 and CCL5 concentrations were significantly decreased in the macular degeneration group compared with controls (p < 0.001) as well as when a cutoff value comparison was used. CCL3 and CCL5 were negatively correlated in cases and positively correlated in controls.

Conclusions: Plasma CCL3 and CCL5 concentrations were significantly decreased and CCL2 concentrations were increased in patients with iAMD compared with controls, suggesting a role for C-C chemokines in the systemic inflammatory processes associated with disease development.

Biomarkers for Nonexudative Age-Related Macular Degeneration and Relevance for Clinical Trials: A Systematic Review

TOPIC

The purpose of the review was to identify structural, functional, blood-based, and other types of biomarkers for early, intermediate, and late nonexudative stages of age-related macular degeneration (AMD) and summarize the relevant data for proof-of-concept clinical trials.

CLINICAL RELEVANCE

AMD is a leading cause of blindness in the aging population, yet no treatments exist for its most common nonexudative form. There are limited data on the diagnosis and progression of nonexudative AMD compared to neovascular AMD. Our objective was to provide a comprehensive, systematic review of recently published biomarkers (molecular, structural, and functional) for early AMD, intermediate AMD, and geographic atrophy and to evaluate the relevance of these biomarkers for use in future clinical trials.

METHODS

A literature search of PubMed, ScienceDirect, EMBASE, and Web of Science from January 1, 1996 to November 30, 2020 and a patent search were conducted. Search terms included "early AMD," "dry AMD," "intermediate AMD," "biomarkers for nonexudative AMD," "fundus autofluorescence patterns," "color fundus photography," "dark adaptation," and "microperimetry." Articles were assessed for bias and quality with the Mixed-Methods Appraisal Tool. A total of 94 articles were included (61,842 individuals).

RESULTS

Spectral-domain optical coherence tomography was superior at highlighting detailed structural changes in earlier stages of AMD. Fundus autofluorescence patterns were found to be most important in estimating progression of geographic atrophy. Delayed rod intercept time on dark adaptation was the most widely recommended surrogate functional endpoint for early AMD, while retinal sensitivity on microperimetry was most relevant for intermediate AMD. Combinational studies accounting for various patient characteristics and machine/deep-learning approaches were best suited for assessing individualized risk of AMD onset and progression.

CONCLUSION

This systematic review supports the use of structural and functional biomarkers in early AMD and intermediate AMD, which are more reproducible and less invasive than the other classes of biomarkers described. The use of deep learning and combinational algorithms will gain increasing importance in future clinical trials of nonexudative AMD.

Plasma Biomarkers of Reticular Pseudodrusen and the Risk of Progression to Advanced Age-Related Macular Degeneration

Purpose

To determine, using an aptamer-based technology in patients with intermediate age-related macular degeneration (AMD), (1) if there is a difference in plasma levels of 4979 proteins in patients with and without reticular pseudodrusen (RPD), and (2) if plasma levels of proteins are related to time to conversion to advanced AMD.

Methods

Patients with intermediate AMD and RPD were identified from an AMD registry. Relative concentrations of each protein were log (base 2) transformed and compared between patients with and without RPD using linear regression. A Cox proportional hazards survival model was fit to each aptamer to quantify associations with time to conversion. A pathway analysis was conducted in converters versus non-converters using the Reactome database.

Results

Of the 109 intermediate AMD patients, 39 had bilateral RPD (36%). Two proteins, TCL1A and CNDP1, were lower in patients in the intermediate AMD group with RPD. Twenty-one patients converted to advanced AMD with a median time to conversion of 25.2 months (range, 2.3-48.5 months) and median follow-up time in non-converters of 26.4 months (range, 0.03-49.7 months). Several proteins (lysozyme C, TFF3, RNAS6, and SAP3) distinguished patients who converted from those who did not convert to advanced AMD. The top conversion pathways included tumor necrosis factors bind their physiological receptors, digestion and absorption, signaling by activin, and signaling by TGF-β family members.

Conclusions

We identified a protein signature related to RPD, as well as to conversion to advanced AMD. The pathway analysis suggests that dysfunction of critical systemic pathways may have links to conversion to advanced AMD.

Translational Relevance

Biomarkers identified in plasma likely reflect systemic alterations in protein expression in patients with intermediate AMD.

Hormone Therapy as a Protective Factor for Age-Related Macular Degeneration

Purpose: The purpose of this study was to determine if the use of menopausal hormone therapy (HT) is related to the development of neovascular (NV) age-related macular degeneration (AMD), geographic atrophy (GA) and/or early/intermediate AMD.Methods: A case-control study was conducted from patients prospectively recruited from July 2014 to June 2019. Cases were females with AMD recruited into a registry and controls were females with age-related cataract and no AMD. Age-related macular degeneration was categorized into NV-AMD, GA, and early/intermediate. Hormone therapy (historic and current) was self-reported by the patient and categorized as ever/never use. Adjusted odds ratios (ORs) from multinomial logistic regressions are presented for each AMD group.Results: Female AMD case patients (n = 409) and controls (n = 132) were included in the analytic database. Almost half (45.5%) of the female AMD patients had NV-AMD, 14.9% had GA, and 39.6% had early/intermediate AMD. Among all study participants, 285 (52.7%) reported historic and/or current use of HT. Controls were significantly more likely to have any HT use (71.2%), compared to 43.0% (p ≤ 0.001) of NV-AMD patients, 47.5% (p = .002) of GA patients, and 50.6% (p ≤ 0.001) of early/intermediate AMD patients. Adjusted for potential confounders of age and Caucasian race, cases were significantly more likely to have lower HT use compared to controls: NV-AMD, OR = 0.31 (95%CI: 0.18-0.54), GA, OR = 0.40 (95%CI: 0.20-0.80), and early/intermediate AMD, OR = 0.36 (95%CI: 0.22-0.61).Conclusion: Our case-control study found that the use of HT was associated with a lower odds of all AMD stages studied: NV-AMD, GA and early/intermediate.

Complement factors and reticular pseudodrusen in intermediate age-related macular degeneration staged by multimodal imaging

Objective

Systemic activation of the complement system in intermediate age-related macular degeneration (AMD) is understudied. Moreover, links between the presence of reticular pseudodrusen (RPD) and systemic complement dysregulation have not been studied. The aim of this study was to determine if there is a difference in plasma complement factor levels in intermediate AMD compared with controls, and if complement levels are related to the presence of RPD.

Methods and analysis

Levels of complement factors C1q (µg/mL), C4 (µg/mL), C2 (µg/mL), Mannose Binding Lectin (ng/mL), C4b (µg/mL), C3 (µg/mL), factor B (µg/mL), factor D (µg/mL), properdin (µg/mL), C3a (ng/mL), iC3b/C3b (ng/mL), Ba (ng/mL), factor H (µg/mL), factor I (µg/mL), C5 (µg/mL), C5a (pg/mL) and SC5b-9 (ng/mL) were measured in plasma.

Results

109 cases and 65 controls were included in the study. Thirty-nine (36%) cases had RPD. Significantly lower systemic levels of: C1q (OR 0.96, 95% CI 0.94 to 0.98), factor B (OR 0.98, 95% CI 0.96 to 0.99), iC3b/C3b (OR 0.97, 95% CI 0.95 to 0.98), factor H (OR 0.99, 95% CI 0.98 to 0.99), factor I (OR 0.83, 95% CI 0.77 to 0.89) and C5 (OR 0.94, 95% CI 0.90 to 0.98) were found in cases versus controls. Significantly elevated levels of: C2 (OR 1.29, 95% CI 1.07 to 1.59), C3a (OR 1.03, 95% CI 1.01 to 1.05) Ba (OR 1.03, 95% CI 1.01 to 1.05) and C5a (OR 1.04, 95% CI 1.02 to 1.07) were found in cases versus controls. Systemic levels of complement factors measured were not related to the presence of RPD.

Conclusions

Levels of several systemic complement pathway factors were found to be altered in intermediate AMD. Systemic levels of complement factors were not related to RPD.