Risk factors for progression of age-related macular degeneration

Potential Efficacy of Metformin for Age-Related Macular Degeneration: A Systematic Review and Meta-Analysis

Topic

Metformin, a widely used diabetes medication, has shown potential for treating age-related macular degeneration (AMD) due to its antioxidative, anti-inflammatory, and antiangiogenic properties. This study aims to systematically review and analyze the efficacy of metformin in reducing AMD prevalence.

Clinical Relevance

Metformin's potential to serve as a treatment for AMD could significantly reduce the burden of vision loss, offering a cost-effective and widely accessible solution.

Methods

A systematic search was conducted in OVID Embase, OVID MEDLINE, Cochrane Library, and Web of Science databases on May 2, 2024. Both observational and interventional studies were included if they involved oral metformin use before AMD diagnosis. Data were extracted and analyzed using a random-effects model meta-analysis, with subgroup analyses based on study design, AMD subtype, sex, and metformin dosage.

Results

Eighteen observational studies were identified, which together included a total of 2 683 234 individuals. Nine studies had a case-control design, 7 were retrospective cohort studies, and 2 were cross-sectional studies. The meta-analysis revealed a significant reduction in the odds of AMD among metformin users (pooled odds ratio [OR] = 0.86, 95% confidence interval = 0.79-0.93, P = 0.0002, I2 = 90%). The association was significant in both patients with diabetes (pooled OR = 0.89) and without diabetes (pooled OR = 0.70), although only 2 studies reported nondiabetic ORs. Dose-response analysis revealed significant protective effects at low doses. Sensitivity analysis indicated that the removal of an outlier study did not alter the overall effect. Bias analysis using the Risk of Bias in Nonrandomized Studies of Interventions tool revealed significant risks of bias, particularly due to confounding.

Conclusion

Although the current evidence suggests a potential protective role of metformin in AMD, all studies showing an effect of metformin have been observational and thus subject to bias. Randomized clinical trials are needed to determine the effectiveness of metformin for preventing the onset of AMD.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

OCT predictors of retinal atrophy in neovascular age-related macular degeneration treated with aflibercept

AIM

To identify optical coherence tomography (OCT) features present at the diagnosis of neovascular age-related macular degeneration (nAMD) that could predict retinal atrophy (RA) and visual performance in patients treated with intravitreal aflibercept.

METHODS

OCT data collected at the time of nAMD diagnosis (T0), after the first (T1) and third (T2) intravitreal aflibercept injection, and 5y post-diagnosis (T3) were analyzed. The study included 46 eyes from patients undergoing treatment. The association of OCT features with RA and visual acuity (VA) development over time were evaluated.

RESULTS

Patients with RA at T3 exhibited worse VA (35.19±5.7 vs 8.90±2.3, P<0.001) and a lower rate of improvement or stability at T2 (90.48% vs 56.00%, P=0.019) and T3 (85.71% vs 8.00%, P<0.001). The development of RA at T3 was linked with type 2 macular neovascularization (MNV; 4.76% vs 36.00%, P=0.013), thinner outer nuclear layer (ONL, 88.89±7.82 µm vs 71.38±14.14 µm, P=0.033), presence of intraretinal fluid (IRF, 42.86% vs 80.00%, P=0.014), presence of IRF without subretinal fluid at T0 (SRF, 4.76% vs 32.00%, P=0.027), and reduced central foveal thickness at T3 (CFT, 190.14±22.79 µm vs 124.32±14.35 µm, P<0.001). The presence of SRF with or without IRF at the diagnosis was comparable between the two groups (90.48% vs 68.00%; P=0.084).

CONCLUSION

Type 2 MNV, reduces ONL and CFT, and IRF presence at baseline may signal a higher risk of RA in treatment-naive nAMD patients, underscoring the importance of these OCT features in early risk assessment and management strategies.

Novel Therapeutic Approaches for Treatment of Diabetic Retinopathy and Age-Related Macular Degeneration

Retina, a light-sensitive layer of tissue of the eye, requires high levels of oxygen for its physiology. Retinal ischemia occurs due to inadequate supply of blood to the retina and choroid. Retinal ischemia is implicated in the development or progression of many ocular diseases, such as diabetic retinopathy (DR) and age-related macular degeneration (AMD). To date, anti-vascular endothelial growth factor (VEGF) treatment has been widely used to manage neovascular diseases associated with retinal ischemia. Nonetheless, a substantial number of patients with DR or AMD still suffer from incomplete response and adverse effects related to its therapy with limitations. Therefore, research scientists have been developing and finding novel treatments to protect against or prevent vision loss in those diseases. In this review article, we summarize the recent novel therapeutic approaches for the treatment of ischemic retinopathy (e.g., cell therapy, advanced molecular targeting, or drug delivery). This summary enables further research to obtain more solid evidence of novel effective drug development in retinal ischemic diseases.

Age-Related Macular Degeneration Pathophysiology and Therapeutic Potential of Tocotrienols: An Update

Age-related macular degeneration (AMD) poses a significant threat to visual health among the elderly, necessitating urgent preventive measures as the global population ages. Extensive research has implicated oxidative stress (OS)-induced retinal damage as a primary contributor to AMD pathogenesis, prompting investigations into potential therapeutic interventions. Among the various nutrients studied for their potential in AMD risk reduction, antioxidants have shown promise, with initial findings from the Age-Related Eye Disease Study suggesting a correlation between antioxidant supplementation and decreased AMD progression. This article explores the scientific foundation supporting the therapeutic efficacy of tocotrienol-rich fraction (TRF) as a viable candidate for slowing AMD progression, based on interventional studies. AMD is characterized by OS, inflammation, dysregulated lipid metabolism, and angiogenesis, all of which TRF purportedly addresses through its potent anti-inflammatory, lipid-lowering, antiangiogenic, and antioxidant properties. The review underscores TRF's promising attributes, aiming to deepen understanding of AMD pathogenesis and advocate for TRF-based pharmacological interventions to enhance therapeutic outcomes. Given the pressing need for effective AMD treatments, TRF represents a promising avenue for intervention, offering hope for improved vision outcomes and enhanced quality of life for individuals affected by this debilitating condition.

Relationship Between Chronic Stress Measured by Allostatic Load and Age-Related Macular Degeneration in the All of Us Research Program

PURPOSE

To assess the longitudinal relationship between age-related macular degeneration (AMD) and allostatic load (AL), an established framework for quantifying the physiologic effects of chronic stress through measurements of systemic biomarkers.

DESIGN

Retrospective case-control study.

METHODS

Participants of the National Institutes of Health All of Us (AoU) Research Program with complete AL biomarker data between February 1985 to May 2022 and with (cases) or without (controls) AMD were identified. AL scores were calculated using the adapted Seeman AL scale consisting of 10 systemic biomarkers: body mass index, systolic blood pressure, diastolic blood pressure, total cholesterol, triglycerides, glomerular filtration rate, albumin, C-reactive protein, and homocysteine. AL score was defined as the number of biomarkers with measurements in the highest risk quartiles. Age was calculated as the median age at time of earliest or latest biomarker measurements. The main outcome was AMD status (AMD or non-AMD). Logistic regression models assessed the association between AL score and AMD after standardization of age and sex and adjustment for race/ethnicity and pack-years of cigarette smoking. Mediation analysis estimated the relationship between race/ethnicity and AMD as mediated by AL score.

RESULTS

Among 1530 participants (221 cases, 1309 controls) with complete biomarker data, there were 44.6% males, 76.1% non-Hispanic Whites (NHWs), 18.6% other specified race/ethnicity (Asian, Black, or Hispanic race/ethnicity), and 5.3% unspecified race/ethnicity. AL scores measured a median of 9.0 (IQR=5.0-14.0) years prior to diagnosis were higher among cases compared to controls (Median [IQR] = 2 [2-4] versus 2 [1-3]; P = .02). On multivariable analysis, higher baseline AL score (OR=1.11) and greater pack-years (OR=1.15 per 10 pack-years) conferred higher risk of AMD (P ≤ .02). Mediation analysis revealed a significant indirect effect that increased risk of AMD among other specified race/ethnicity participants compared to NHW participants through higher AL score (OR=1.07 per unit [1.01-1.15]).

CONCLUSION

All of Us participants diagnosed with AMD had greater AL score 9.0 years prior to AMD diagnosis. Chronic stress appears to increase risk for AMD and may contribute to racial/ethnic differences in disease prevalence.

Molecular Mechanisms of Vitamin E in Ocular Neurodegenerative Disorders: An Update on the Emerging Evidence and Therapeutic Implications

Vitamin E is renowned for its potent antioxidant properties, crucial for shielding cells against oxidative stress and damage. Deficiency in this vitamin can lead to various health issues, including neurodegenerative diseases, due to its pivotal role in preserving cell membrane integrity and combating cellular oxidative damage. While its importance for overall health, including neurodegeneration, is acknowledged, the specific correlation between vitamin E deficiency and distinct ocular neurodegenerative disorders need to be further explored. This review delves into the molecular mechanisms of vitamin E in ocular neurodegenerative disorders; diabetic retinopathy, age-related macular degeneration, glaucoma, and cataracts, and emphasising the therapeutic implications drawn from existing evidence. Relationship between vitamin E and ocular neurodegenerative disorders is widely researched on, with its primary protective mechanisms attributed to its antioxidant and anti-inflammatory properties. However, studies on the supplementation of vitamin E among human subjects present mixed results, suggesting its complexities and variability depending on factors such as the specific disorder, disease stage, genetic differences, and form of vitamin E utilized. In conclusion, while vitamin E holds promise in mitigating ocular neurodegeneration through its antioxidant and anti-inflammatory properties, its supplementation's efficacy remains nuanced and context dependent. More research works are essential to elucidate its precise role and therapeutic potential in combating various ocular neurodegenerative disorders.

CLINICAL COURSE AND PROGNOSTIC FACTORS IN NONNEOVASCULAR AGE-RELATED MACULAR DEGENERATION WITH SUBRETINAL FLUID

PURPOSE

To investigate the clinical course and prognostic factors of age-related macular degeneration without macular neovascularization (MNV) in patients presenting with pigment epithelial detachment (PED) and the associated subretinal fluid (SRF).

METHODS

Morphological characteristics of spectral-domain optical coherence tomography images were analyzed to determine anatomic outcomes. Factors associated with the progression to late AMD, defined as complete retinal pigment epithelium and outer retinal atrophy (cRORA) or MNV, were investigated.

RESULTS

Fifty eyes of 41 patients were included in this study. The most common SRF location was the angle of the PED (56%), and there was a significant decrease in SRF thickness and PED height and width over the follow-up period. Eleven (22%) eyes developed cRORA, and seven (14%) eyes developed MNV during a mean period of 52.1 months. Multivariate analysis revealed that hyperreflective foci and MNV in the fellow eye were associated with the development of cRORA, and higher PED height was a significant factor associated with the development of MNV.

CONCLUSION

In patients with AMD, SRF can be accompanied by PED in the absence of MNV. Notably, patients with this characteristic entity can progress to late AMD, including cRORA and MNV, in a significant proportion of cases.

Association of systemic inflammatory biomarkers with ocular disease: a large population-based cross-sectional study

BACKGROUND

The aim of this study was to explore the association of systemic inflammatory biomarkers (systemic immune-inflammation (SII) index and systemic inflammatory response index (SIRI)) with the prevalence of ocular disease in the general population of the United States (U.S.).

METHODS

We conducted a cross-sectional study of subjects in the National Health and Nutrition Examination Survey 2005-2008 years. For the analysis of the association of SII index, and SIRI with the prevalence of ocular disease (glaucoma, cataract, age-related macular degeneration (ARMD), and diabetic retinopathy), the restricted cubic spline (RCS) plot, multivariable logistic regression models, and subgroup analysis were performed.

RESULTS

There was a total of 5377 individuals. As shown by the RCS plot, SII index and SIRI were linked with ARMD risk in a U-shaped pattern. Additionally, the SII index and SIRI were linearly positive with glaucoma and cataract. Finally, the risk of diabetic retinopathy was associated with the L-shaped and N-shaped curves of the SII index and SIRI, respectively.

CONCLUSIONS

Two new systemic inflammatory biomarkers, SII index and SIRI, are closely related to the risk of eye disease. There are different associations between SII index and different ocular diseases. This should raise more concerns and lead to better prevention strategies for systemic inflammation.

The Role of the Ubiquitin System in Eye Diseases

The ubiquitin-proteasome system (UPS) is a fundamental process that regulates various biological functions, including immune response, cell cycle, oxidative stress, migration, and cellular proliferation. This system is responsible for the degradation of proteins, while proteasomes play a significant role in mechanisms involved in health and human diseases. The participation of the UPS in immune response is particularly relevant, leading to the involvement of immunoproteasomes. This specialized proteasome is involved in the processing and presentation of antigenic peptides, making it crucial for proper immune function. Moreover, the impact of the UPS is considered essential in understanding several diseases, such as neurodegenerative disorders, infections, and vascular diseases. The dysregulation of the UPS may contribute to the pathogenesis of these conditions, highlighting its importance as a potential therapeutic target. Interestingly, the UPS is also related to ocular structures, playing a role in visual perception and ocular homeostasis. This involvement in the regulation of various ocular processes suggests its potential impact on both anterior and posterior eye pathologies. This review aims to discuss the general considerations of the UPS and provide information about its participation in anterior and posterior eye pathologies. By understanding its role in ocular health and disease, researchers and clinicians may explore novel therapeutic strategies targeting the UPS for the treatment of various eye conditions. In conclusion, the UPS is a crucial player in biological processes, with far-reaching implications in health and disease, including the anterior and posterior segments of the eye. Further research in this field may lead to the development of innovative therapies and a better understanding of the complex mechanisms underlying various eye disorders.

Exposure assessments of cadmium and lead with age-related eye disease: A systematic review and meta-analysis

BACKGROUND

Age-related eye diseases, such as macular degeneration, cataracts, and glaucoma, are significant causes of vision loss in older adults. Emerging evidence suggests that environmental exposure to heavy metals, particularly Cadmium and lead, may play an essential role in the onset and progression of these conditions.

METHODS

This systematic review and meta-analysis aimed to evaluate the association between Cadmium and lead exposure and the risk of age-related eye diseases. A comprehensive literature search was conducted across multiple databases, including PubMed, Embase, Scopus, and Web of Science, covering studies published up to July 2024. The review included observational studies on the relationship between Cadmium or lead exposure and specific eye conditions. Data extraction and quality assessment were performed independently by two reviewers. The meta-analysis utilized a random effects model to analyze cadmium and lead levels in patient and control groups, with subgroup analyses based on the type of eye disease and study design.

RESULTS

The results revealed a significant association between cadmium exposure and an increased risk of eye diseases, particularly cataracts and glaucoma. Lead exposure was also linked to a higher risk of cataracts and macular degeneration. The study found substantial heterogeneity among the included studies, highlighting the variability in exposure assessment and population characteristics.

CONCLUSIONS

Despite these variations, the findings underscore the importance of addressing environmental exposures to toxic metals as potential risk factors for age-related eye diseases. Further research is needed to clarify the underlying mechanisms and to develop targeted interventions for reducing these risks.

Predictors of Visual Response After Lapse in Treatment Among Patients With Neovascular Age-related Macular Degeneration

BACKGROUND AND OBJECTIVE

This study aimed to analyze baseline predictors of visual response in patients with neovascular age-related macular degeneration (nAMD) who have undergone lapses in treatment with anti-VEGF therapy. The mainstay treatment option for nAMD is intravitreal vascular endothelial growth factor inhibitor (anti-VEGF) therapy. Given the chronic nature of nAMD, patients who undergo lapses in treatment with these agents can have progression of their disease.

PATIENTS AND METHODS

This retrospective, comprehensive chart review included 261 adults aged 18 years or older who were diagnosed with nAMD between January 2012 and June 2020 and had undergone at least one anti-VEGF injection prior to an unintended lapse in follow-up of 3 months or greater. Following exclusion criteria, in which individuals were not administered an anti-VEGF injection at the pre-lapse visit, a total of 163 patients were analyzed. Patients were separated into "vision loss" and "stable vision" categories and classified based on degree of vision loss. A stepwise backward logistic regression was used to analyze baseline medical and ophthalmic factors between each group to determine which factors were more likely to be associated with more significant vision loss.

RESULTS

Out of 261 nAMD patients reviewed, 163 patients were investigated in the main analysis. Higher cube volume (1.24 ± 0.24, P = 0.22), and lapse length (2.89 ± 0.056, P = 0.004) increased the likelihood of vision loss, while lack of smoking history (-2.07 ± 0.46, P = 0.038) decreased the likelihood. The two groups were significantly different in post-lapse ophthalmologic continuous variables, including cube volume (9.69 ± 0.98 and 10.2 ± 1.39 in the stable vision and unstable vision groups, respectively, P = 0.01) and cube average thickness (269 ± 27.3 and 282 ± 38.4 in the stable vision and unstable vision groups, respectively, P = 0.02). The main model had an area under the curve (AUC) of 58% and predictive accuracy of 78.1%.

CONCLUSION

The calculated AUC was not high enough to establish reliable predictability in this study. However, additional factors may need to be considered for greater predictability. [Ophthalmic Surg Lasers Imaging Retina 2025;56:XX-XX.].

Modifiable Lifestyle Risk Factors and Strategies for Slowing the Progression of Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is a multifactorial disorder influenced by genetic, lifestyle, nutritional, and systemic health factors that contribute to increased oxidative stress and chronic inflammation in the retina. This article reviews the recent literature on modifiable lifestyle risk factors for the development and progression of AMD. Smoking (current and former), physical inactivity, prolonged sunlight exposure, as well as conditions such as diabetes, hypertension, cardiovascular disease, and obesity have all been associated with an increased risk of early AMD and its progression. The Age-Related Eye Disease Studies (AREDS and AREDS2) have shown that a specific combination of vitamins E and C, zinc, copper, lutein, and zeaxanthin can significantly reduce the risk of AMD progressing from dry to wet form. Additionally, adherence to a Mediterranean diet, rich in vegetables, fruits, legumes, whole grains, and nuts, has been linked to a lower risk of both early and late AMD. Emerging evidence suggests that these benefits may be influenced by the gut microbiota, as well as genetic and epigenetic factors. Further research into the interactions between these risk factors could pave the way for targeted therapies aimed at preventing or slowing AMD progression.

Lipid profile in the aqueous humor of diabetic macular edema patients

Diabetic macular edema (DME) has become a global public health focus due to its increasing prevalence and significant impact on central vision. The aim of this study is to analyze the lipid profile characteristics of aqueous humor in DME patients and to identify differential lipid compounds that may serve as potential biomarkers for the pathogenesis and therapeutic intervention. A non-targeted lipidomics approach based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to analyze the lipid profiles of aqueous humor from patients with diabetic macular edema (DME group, 11 cases), diabetic cataracts (DC group, 14 cases), and age-related cataract (ARC group, 15 cases). The validation of identified lipid compounds through Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA) was conducted to examine possible varied lipid markers, setting the parameters of VIP > 1 and p < 0.05. Additionally, correlation network analysis, community classification, and functional enrichment analysis were performed on the differential lipids. 90 lipid compounds were identified, encompassing a range of 13 lipid categories. There were significant differences in the lipid profiles of the aqueous humor in DME. The lipid profile characteristics of aqueous humor in patients with DME are described for the first time. Compared to the control group. Various lipid metabolic disorders, such as sphingolipids particularly ceramide, phospholipids, and triglycerides, are involved in the pathogenesis of DME, and can be further studied as potential diagnostic and therapeutic lipid biomarkers.

The AMD-associated genetic polymorphism CFH Y402H confers vulnerability to Hydroquinone-induced stress in iPSC-RPE cells

Introduction

Age-related macular degeneration (AMD), a degenerative disease of the macula, is caused by an interplay of diverse risk factors (genetic predisposition, age and lifestyle habits). One of the main genetic risks includes the Y402H polymorphism in complement Factor H (FH), an inhibitor of complement system activation. There has been, and continues to be, much discussion around the functional consequences of this Y402H polymorphism, whether the soluble FH protein confers its risk association, or if the cells expressing the protein themselves are affected by the genetic alteration. In our study, we examined the cell characteristics of the retinal pigment epithelium (RPE) cells, which play a major role in retinal homeostasis and stability and which are synonymously linked to AMD.

Methods

Here, we employ RPE cells derived from induced pluripotent stem cells (iPSC) generated from donors, carrying either homozygous 402Y (low risk) or 402H (high risk) variants of the CFH gene. RPE cells were treated with Hydroquinone (HQ), a component of cigarette smoke, to induce oxidative damage.

Results

Intriguingly, RPE cells carrying high genetic risk proved more vulnerable to oxidative insult when exposed to HQ, as demonstrated by increased cytotoxicity and caspase activation, compared to the low-risk RPE cells. The exposure of RPE cells to RPE conditioned medium, normal human serum (NHS) and inactivated NHS (iNHS) had minimal impact on cell cytotoxicity and caspase activation, nor did the presence of purified soluble FH rescue the observed effects. Considering the known connection of oxidative stress to proteotoxic stress and degrading processes, we investigated the unfolded protein response (UPR) and autophagy. When exposed to HQ, RPE cells showed an increase in autophagy markers; however, iPSC-RPE cells carrying high genetic risk showed an overall reduced autophagic flux.

Discussion

Our findings suggest that the degree of cellular susceptibility to oxidative stress is not conferred by soluble FH protein and other complement sources, but intercellularly because of the corresponding genetic risk predisposition. Our data support the hypothesis that RPE cells carrying high genetic risk are less resilient to oxidative stress.

Photosensitizer formulations in photodynamic therapy of age-related macular degeneration

Age-related macular degeneration (AMD) is a progressive degenerative disease that leads to visual impairment, predominantly affecting the elderly. Despite significant advancements in treatment, a definitive cure remains elusive. Current therapeutic strategies only slow down disease progression, inhibiting abnormal blood vessels growth, and preserving or improving vision. Among these strategies, photodynamic therapy (PDT) has emerged as a promising treatment, particularly for neovascular form, the most severe form of the disease. Although several photosensitizers (PS) have been developed, only one has received clinical approval for use in AMD. This treatment involves the intravenous administration of a photosensitizing agent that preferentially accumulates in the abnormal blood vessels beneath the macula. Upon activation by targeted laser light, the PS triggers photochemical reactions, leading to vascular occlusion and the reduction of choroidal neovascularization. This review provides a comprehensive overview of both experimental and clinical studies on PDT for AMD, discussing the current state of research, challenges in treatment optimization, and potential future directions to enhance this therapeutic approach.

The Spectrum of Functional, Structural, and Patient-Reported Outcomes in Intermediate Age-Related Macular Degeneration: A MACUSTAR Study Report

INTRODUCTION

There is an unmet medical need for therapies in intermediate age-related macular degeneration (iAMD). The prospective European multicenter cohort study MACUSTAR validates structural, functional, and patient-reported iAMD endpoints for use in future trials. The multiplicity of assessments allows characterizing iAMD in more dimensions than previously available. We describe the heterogeneity of assessments in the iAMD baseline cohort of the MACUSTAR study.

METHODS

A wide range of assessments was administered across 20 European study sites in accordance with established guidelines. These assessments encompassed multiple structural evaluations, such as color fundus photography, fundus autofluorescence, and optical coherence tomography. Additionally, functional tests were conducted, including assessments of best-corrected and low-luminance visual acuity (VA), Moorfields acuity, contrast sensitivity, reading speed, mesopic and scotopic microperimetry, and dark adaptometry. Moreover, patient-reported outcome assessments, specifically the Vision Impairment in Low Luminance questionnaire, were also incorporated into the evaluation process. Associations between variables were investigated using Phi coefficients, Pearson correlation coefficients and age-corrected regression models.

RESULTS

Five-hundred eighty-five individuals with iAMD (66% women; mean (standard deviation) age: 72 ± 7 years) were included in the MACUSTAR study. Forty-nine percent had pigmentary abnormalities, 27% had reticular pseudodrusen; 10% and 9% had incomplete and complete retinal pigment epithelium and outer retinal atrophy at baseline, respectively. Mean best-corrected VA, low-luminance VA and mesopic average threshold on microperimetry at baseline were 0.03 ± 0.11 logMAR, 0.24 ± 0.16 logMAR, and 23.3 ± 3.7 dB. Mean Vision Impairment in Low Luminance (VILL) subscale scores at baseline were 2 ± 2 to 2 ± 3 logits. Phi coefficients between structural assessments ranged between 0.17 and 0.22 (median 0.21); correlation coefficients between function tests ranged between 0.07 and 0.69 (median 0.34) and between VILL scores ranged between 0.21 and 0.68 (median 0.23).

CONCLUSION

The findings from this broad and comprehensive spectrum of assessments of structure, function, and patient-reported outcomes in iAMD suggest that the disease spectrum is diverse and heterogeneous and that further efforts are necessary to fully understand and characterize iAMD in all its complexities. A further in-depth characterization will enable novel enrichment strategies for clinical trials in iAMD.

High Levels of C5a Are Associated With Reduced Macular Sensitivity in Patients With Myeloproliferative Neoplasms

Purpose

Previous findings indicate that patients with myeloproliferative neoplasms (MPN) exhibit elevated levels of inflammatory biomarkers and have a high prevalence of AMD. In this study, we aim to determine whether drusen and systemic inflammation in patients with MPN affect macular sensitivity in the same manner as in patients with AMD.

Methods

The study was conducted as a prospective cross-sectional study. A total of 139 study eyes of 71 patients were included in this study. We measured macular sensitivity using microperimetry and extracted blood samples to evaluate systemic inflammation markers.

Results

Multilevel linear mixed-effect analysis did not show any difference in macular sensitivity when comparing eyes of MPN patients with AMD to those without drusen (β = -0.254, P = 0.657). However, higher levels of the complement system fragment C5a were significantly correlated with decreased total macular sensitivity (β = -0.561, P = 0.027), irrespective of the presence of drusen.

Conclusions

We found that high levels of the systemic inflammation marker C5a are associated with reduced macular sensitivity, regardless of the presence of visible degenerative changes in the macular area. These findings suggest an early contribution of the complement system to macular sensitivity.

"Advances in biomarker discovery and diagnostics for alzheimer's disease"

BACKGROUND

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by intracellular neurofibrillary tangles with tau protein and extracellular β-amyloid plaques. Early and accurate diagnosis is crucial for effective treatment and management.

OBJECTIVE

The purpose of this review is to investigate new technologies that improve diagnostic accuracy while looking at the current diagnostic criteria for AD, such as clinical evaluations, cognitive testing, and biomarker-based techniques.

METHODS

A thorough review of the literature was done in order to assess both conventional and contemporary diagnostic methods. Multimodal strategies integrating clinical, imaging, and biochemical evaluations were emphasised. The promise of current developments in biomarker discovery was also examined, including mass spectrometry and artificial intelligence.

RESULTS

Current diagnostic approaches include cerebrospinal fluid (CSF) biomarkers, imaging tools (MRI, PET), cognitive tests, and new blood-based markers. Integrating these technologies into multimodal diagnostic procedures enhances diagnostic accuracy and distinguishes dementia from other conditions. New technologies that hold promise for improving biomarker identification and diagnostic reliability include mass spectrometry and artificial intelligence.

CONCLUSION

Advancements in AD diagnostics underscore the need for accessible, minimally invasive, and cost-effective techniques to facilitate early detection and intervention. The integration of novel technologies with traditional methods may significantly enhance the accuracy and feasibility of AD diagnosis.

Investigating the Link between Psychological Well-Being and Early-Stage Age-Related Macular Degeneration: A Mendelian Randomization Analysis

PURPOSE

While some studies have started to focus on the link between psychological well-being and age-related macular degeneration (AMD), the relationship remains uncertain. Our research aims to provide new insights into this association, laying a foundation for future interventions and addressing existing knowledge gaps.

METHODS

We utilized the "TwoSampleMR" package in R for a bidirectional Mendelian randomization analysis of psychological well-being (subjective well-being, depression, neuroticism, and Sensitivity to Environmental Stress and Adversity) and early-stage AMD. Causal effects were estimated using the inverse-variance weighted method, and additional methods included weighted median and MR-Egger regression. Sensitivity analyses included Cochran's Q test, MR-Egger intercept analysis, MR-PRESSO, and leave-one-out analysis.

RESULTS

The study found that the population with genetic predisposition to neuroticism had a 39.7% lower risk of early-stage AMD (OR = 0.603, 95% CI = 0.385-0.945, p = 0.027). Conversely, the population with genetic predisposition to subjective well-being had a 3.2% increased risk of early-stage AMD (OR = 1.032, 95% CI = 1.003-1.063, p = 0.029). No significant causal relationships were found from depression or Sensitivity to Environmental Stress and Adversity to early-stage AMD, nor from early-stage AMD to psychological well-being.

CONCLUSION

This study provides preliminary evidence that the relationship between psychological well-being and early-stage AMD may be complex and multifaceted. It suggests that moderate neuroticism levels might reduce early-stage AMD risk through health behaviors, pathophysiological mechanisms, and other factors, while high subjective well-being levels might increase this risk similarly. However, these findings are insufficient for preventive strategies due to a lack of substantial evidence and still require extensive experimental research for further validation.

Artificial intelligence in assessing progression of age-related macular degeneration

The human population is steadily growing with increased life expectancy, impacting the prevalence of age-dependent diseases, including age-related macular degeneration (AMD). Health care systems are confronted with an increasing burden with rising patient numbers accompanied by ongoing developments of therapeutic approaches. Concurrent advances in imaging modalities provide eye care professionals with a large amount of data for each patient. Furthermore, with continuous progress in therapeutics, there is an unmet need for reliable structural and functional biomarkers in clinical trials and practice to optimize personalized patient care and evaluate individual responses to treatment. A fast and objective solution is Artificial intelligence (AI), which has revolutionized assessment of AMD in all disease stages. Reliable and validated AI-algorithms can aid to overcome the growing number of patients, visits and necessary treatments as well as maximize the benefits of multimodal imaging in clinical trials. Therefore, there are ongoing efforts to develop and validate automated algorithms to unlock more information from datasets allowing automated assessment of disease activity and disease progression. This review aims to present selected AI algorithms, their development, applications and challenges regarding assessment and prediction of AMD progression.

Associations between co-exposure to multiple heavy metals and age-related macular degeneration: A cross-sectional study

BACKGROUND & AIMS

Accumulating evidence suggests that exposure to single heavy metal can facilitate the progression of age-related macular degeneration (AMD). However, the effects of exposure to mixtures of heavy metals on AMD remain largely unexplored. This study aims to investigate both the joint and individual impacts of arsenic (As), mercury (Hg), cadmium (Cd), and lead (Pb) on AMD within a co-exposure framework.

METHODS

Data from subjects participating the US National Health and Nutrition Examination Survey (NHANES, 2005-2008) were analyzed. Concentrations of As, Hg, Cd, and Pb were determined in urine by inductively coupled plasma dynamic reaction cell mass spectrometry (ICP-DRC-MS) for As and Hg, and inductively coupled plasma mass spectrometry (ICP-MS) for Cd and Pb. The weighted quantile sum (WQS) and Bayesian kernel machine regression (BKMR) models were employed to assess the effects of heavy metal mixtures on AMD risk.

RESULTS

Both WQS and BKMR analyses consistently revealed a significant overall association between heavy metal mixtures and the risk of all types of AMD. The combined effect was more evident among patients with early AMD compared to those with late AMD. Cd and Hg were the main contributors driving these combined effects within the context of metal mixtures. Elevated urinary levels of Cd were positively correlated with an increased risk for all types as well as early AMD. Higher exposure to Hg corresponded with an elevated risk for early AMD. Furthermore, BKMR analysis indicated that the influence of Cd on early AMD exhibited a non-linear pattern.

CONCLUSIONS

Our findings suggest that co-exposure to As, Hg, Cd, and Pb is associated with an elevated risk for developing AMD, particularly in its early stages. Furthermore, excessive exposure to Cd and Hg has been identified as key contributing factors in this process.

A comprehensive review on early detection of drusen patterns in age-related macular degeneration using deep learning models

Age-related Macular Degeneration (AMD) is a leading cause of visual impairment and blindness that affects the eye from the age of fifty-five and older. It impacts on the retina, the light-sensitive layer of the eye. In early AMD, yellowish deposits called drusen, form under the retina, which could result in distortion and gradual blurring of vision. The presence of drusen is the first sign of early dry AMD. As the disease progresses, more and larger deposits develop, and blood vessels grow up from beneath the retina leading to leakage of blood, that damages the retina. In advanced AMD, peripheral vision may remain, but the straight vision is lost. Detecting AMD early is crucial, but treatments are limited, and nutritional supplements like AREDS2 formula may slow disease progression. AMD diagnosis is primarily achieved through drusen identification, a process involving fundus photography by ophthalmologists, but the early stages of AMD make this task challenging due to ambiguous drusen regions. Furthermore, the existing models have difficulty in correctly predicting the drusen regions because of the resolution of fundus images, for which a solution is proposed as a model based on deep learning. Performance can be optimized by employing both local and global knowledge when AMD issues are still in the early phases. The area of the retina where drusen forms were identified by image segmentation, and then these deposits were automatically recognized through pattern recognition techniques.

Neurodegeneration and choroidal vascular features on OCT in the progression to advanced age-related macular degeneration

AIM

To quantify and compare longitudinal thickness changes of the ganglion cell complex (GCC) and the choroid in patients with different patterns of age-related macular degeneration (AMD) progression.

METHODS

Retrospective cohort analysis of anonymized data from participants aged 50y or more and diagnosed with early/intermediate AMD in at least one eye (with no evidence of advanced AMD). A total of 64 participants were included from the Instituto de Retina de Lisboa (IRL) study (IPL/2022/MetAllAMD_ESTeSL) and divided into 4 groups according to the Rotterdam classification for AMD. Spectral domain optical coherence tomography (SD-OCT) was used to assess and quantify GCC and choroid thickness at two time points (first visit vs last visit) with a minimum interval of 3y.

RESULTS

In the GCC inner ring, a thinner thickness (P=0.001) was observed in the atrophic AMD group (51.3±21.4 µm) compared to the early AMD (84.3±11.5 µm), intermediate AMD (77.6±16.1 µm) and neovascular AMD (88.9±16.3 µm) groups. Choroidal thickness quantification showed a generalized reduction in the central circle (P=0.002) and inner ring (P=0.001). Slight reductions in retinal thickness were more accentuated in the inner ring in the atrophic AMD (-13%; P<0.01).

CONCLUSION

The variation of the analyzed structures could be an indicator of risk of progression with neurodegenerative (GCC) or vascular (choroid) pattern in the intermediate and atrophic AMD. The quantification of both structures can provide important information about the risk of disease progression in the early and intermediate stages but also for the evolution pattern into late stages (atrophic or neovascular).

Real world pharmacovigilance assessment of drug related macular degeneration risks

Macular degeneration is a leading cause of irreversible vision loss, significantly impacting quality of life. To enhance clinical practice and reduce the risk of drug-related macular degeneration, we analyzed drug-related trends using real-world data. Disproportionality analysis of adverse event reports from the FDA Adverse Event Reporting System (FAERS, 2004-2023) identified 67,683 cases involving 1402 drugs. Among these, 42 drugs were linked to significant risks, including treatments for breast cancer (tamoxifen, raloxifene, anastrozole, letrozole) and diabetes (insulin lispro, insulin human). The BCPNN algorithm revealed that 45.2% (19/42) of these drugs had the strongest associations with macular degeneration, with pentosan polysulfate sodium, travoprost, and tolterodine being the highest-risk drugs. Lifitegrast, nicotine, and travoprost were associated with the shortest onset times for ocular adverse events. Among drug classes, glucocorticosteroids were linked to the most rapid onset of ocular side effects (P < 0.001), typically occurring within two months compared to other drugs. Drug-related macular degeneration was more common in women (70.4%) and predominantly affected those aged 60-80. The incidence of drug-related macular degeneration has steadily increased in recent years. This study offers valuable pharmacovigilance insights, highlighting drugs and demographic factors linked to macular degeneration.

Association of Hyperautofluorescence Signals with Geographic Atrophy Progression in the METformin for the MINimization of Geographic Atrophy Progression Trial

Purpose

To investigate the association between rim area focal hyperautofluorescence (RAFH) signals and geographic atrophy (GA) growth rates, as well as the impact of oral metformin on the longitudinal change of RAFH.

Design

Secondary analysis of a randomized controlled trial.

Participants

Seventy-one eyes from 44 participants with GA and ≥6 months of follow-up in the METformin for the MINimization of geographic atrophy progression study.

Methods

Fundus autofluorescence images were captured using a 488 nm excitation wavelength. Two masked graders identified and measured RAFH lesions using proprietary semiautomatic segmentation software and ImageJ. We calculated RAFH by dividing the areas of hyperautofluorescence within a 450-μm rim circumscribing the GA by the total area enclosed within this rim.

Main Outcome Measures

Longitudinal changes in RAFH and GA area.

Results

Baseline RAFH was positively associated with the baseline square root of GA area 0.065/year (P < 0.001). In the entire study cohort, higher baseline RAFH was associated with a faster GA area growth rate in mm2/year (Spearman's ρ = 0.53; P < 0.001). The association became weaker in square root-transformed GA area growth (ρ = 0.19, P = 0.11) and perimeter-adjusted GA growth rate (ρ = 0.28, P = 0.02), achieving statistical significance only in the latter. When this analysis was stratified into 3 baseline GA tertiles, the first and second tertiles showed weak to moderate association with statistical significance in all 3 modes of GA growth rates. Rim area focal hyperautofluorescence increased slightly but significantly over time at 0.020/year (P < 0.01). Rim area focal hyperautofluorescence increased slightly but significantly over time at 0.020/year (P < 0.01). The use of oral metformin was not significantly associated with the change in RAFH over time compared with the observation group (0.023/year vs. 0.016/year; P = 0.29).

Conclusions

Increased baseline RAFH is associated with faster GA area progression. However, the effect size of this association may depend on the baseline GA lesion size such that small to medium-sized GA lesions display this relationship regardless of the mode of the calculation of GA growth rate.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Dry and neovascular "wet" age-related macular degeneration: Upcoming therapies

The age-related macular degeneration (AMD) field is witnessing promising advancements in therapeutic options. Breakthrough drugs such as pegcetacoplan and avacincaptad have been FDA-approved for dry AMD, marking a significant development as there were no treatment options until August 2023. While several antivascular endothelial growth factor (VEGF) inhibitors have been approved for wet AMD, challenges persist with the need for frequent dosing. New treatments such as gene therapy, cell therapy, WNT pathway agonists, complement inhibitors, and anti-VEGF combination drugs are under development to address these issues. These developments are exciting and hold promise for transforming the field of medicine, offering hope for improved outcomes and enhanced patient care in managing AMD.

Ranibizumab treatment improves the reading speed of patients with neovascular age-related macular degeneration: A nonrandomized clinical trial using the Radner reading chart

PURPOSE

Intravitreal injections with anti-vascular endothelial growth factor (VEGF) drugs can slow progression in neovascular age-related macular degeneration (nAMD). Best spectacle-corrected visual acuity (BSCVA) and/or central retinal thickness (CRT) are common barometers of efficacy of this treatment. However, BSCVA does not accurately measure reading ability, which is often severely impacted by nAMD. Since most studies on the effect of intravitreal anti-VEGF injections on reading ability in nAMD have limitations, we conducted an open-label nonrandomized non-blinded self-controlled clinical trial using Radner Charts, a standardized, validated tool for measuring reading ability.

METHODS

Patients newly diagnosed with active nAMD and scheduled to undergo induction ranibizumab treatment (monthly treatments for 3months) were recruited by convenience sampling in 2010-2013 at a university hospital. The primary outcome was change in Radner Chart-determined reading speed (maximum words/minute [wpm]) at 3months (1month post-third injection) relative to baseline. Secondary outcome measures were 3-month change in BSCVA and CRT. Treatment-induced effects on wpm, BSCVA, and CRT were determined with Wilcoxon tests. Spearman correlations between these variables were evaluated.

RESULTS

The injections significantly improved wpm (48 to 75), BSCVA (+9 letters), and CRT (357 to 224μm) (all P<0.0001). BSCVA, but not CRT, correlated with wpm at baseline and 3months (P=0.0004 and 0.03, respectively). BSCVA and CRT were not correlated, unless change in these variables was considered, possibly because of a non-linear relationship.

CONCLUSION

Anti-VEGF treatment significantly improved reading ability. Whether BSCVA can serve as a clinically meaningful assessment of reading ability requires further research. Baseline variables may not help to identify patients with poor reading speed responses to treatment.

Nanocarrier-Based, ocular drug delivery: Challenges, prospects, and the therapeutic landscape in the United Arab Emirates

Human eyes have the most complex and advanced physiological defense barriers. Due to these barriers, efficient delivery of ocular drugs is a major challenge in the treatment of eye diseases and disorders. Posterior eye diseases such as retinopathy are the leading causes of impaired vision and blindness globally. The topical and systemic administration of drugs such as eye drops, ointments, intravitreal injections, intraocular implants, contact lenses, and emulsions are the perennial approaches employed to treat ocular diseases. However, these modalities are inefficient due to the low bioavailability of the active drug and the potential for drug-related cytotoxicity to the ocular tissue. In this review, the conventional approaches in ocular drug delivery systems (DDSs) are explored and the limitations associated with each technique are elucidated. A comparison between the different DDSs is presented, showing the most effective treatment techniques available to date. In addition, this review presents recent advances in the field of nanocarriers and microcarriers used in ocular drug delivery systems such as nanoparticles, nano-suspensions, nanofibers, nanogels, nano-liposomes, nano micelles, dendrimers, contact lens, microneedle, and implants. Further, this review identifies the utility of nano-carriers in enabling the development of new-generation ocular DDSs with low toxicity, high efficiency, and high stability of targeted drug delivery systems to overcome the limitations observed with conventional ocular DDSs. In addition, this manuscript sheds light on the incidence and unique landscape of ocular diseases in the United Arab Emirates (UAE), and the potential for employing novel ocular DDSs for targeted treatment of conditions such as diabetic retinopathy in the UAE. It also discusses the putative role genetic variants of the VEGF gene may play in predisposing the local population in the UAE to developing posterior eye segment diseases such as retinopathy.

Association between Obstructive Sleep Apnea and Age-related Macular Degeneration Development and Progression

OBJECTIVE

To evaluate the risk of age-related macular degeneration (AMD) development and progression in individuals with diagnosed obstructive sleep apnea (OSA).

DESIGN

Retrospective cohort study.

SUBJECTS

Before propensity score matching (PSM), 60 652 and 1 173 723 individuals with OSA or not, respectively, were included in the study. After PSM and applying inclusion/exclusion criteria, 58 700 individuals in each cohort were subsequently analyzed.

METHODS

Data were collected using TriNetX, a deidentified electronic health records research network. Individuals with an International Classification of Diseases, 10th Revision, code for OSA confirmed with polysomnography and an additional code for continuous positive airway pressure use were compared with individuals without diagnosed OSA (control cohort) for the development of main outcome measures at 5 years. Secondary analyses were included to assess nonadvanced AMD progression in individuals with and without diagnosed OSA at 5 years.

MAIN OUTCOME MEASURES

The main outcome measures were the incidence of AMD, macular hemorrhage, legal blindness, and requiring anti-VEGF intervention at 5 years. Individuals with nonadvanced AMD with and without an OSA diagnosis were separately analyzed for progression to late AMD and the development of macular hemorrhage, legal blindness, and requiring anti-VEGF therapy at 5 years.

RESULTS

At 5 years, individuals with diagnosed OSA had a significantly elevated risk of nonexudative AMD (hazard ratio [HR], 2.64; 95% confidence interval [CI], 2.37-2.96; P < 0.001), exudative AMD (HR, 2.48; 95% CI, 1.99-3.11; P = 0.002), and requiring anti-VEGF therapy (HR, 2.85; 95% CI, 2.26-3.59; P < 0.001) compared with the control cohort. In the secondary analysis, individuals with nonadvanced AMD with diagnosed OSA were associated with an elevated risk of geographic atrophy (HR, 7.00; 95% CI, 4.47-11.0; P = 0.03), exudative AMD (HR, 2.87; 95% CI, 2.37-3.48; P = 0.03), and requiring anti-VEGF injections (HR, 4.72; 95% CI, 3.59-6.22; P = 0.02) compared with those with nonadvanced AMD without diagnosed OSA.

CONCLUSIONS

In a large, heterogeneous database, an elevated risk of developing AMD and progression to later stages of the disease was observed among individuals with diagnosed OSA.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Different Therapeutic Approaches for Dry and Wet AMD

Age-related macular degeneration (AMD) is the most common cause of irreversible loss of central vision in elderly subjects, affecting men and women equally. It is a degenerative pathology that causes progressive damage to the macula, the central and most vital part of the retina. There are two forms of AMD depending on how the macula is damaged, dry AMD and wet or neovascular AMD. Dry AMD is the most common form; waste materials accumulate under the retina as old cells die, not being replaced. Wet AMD is less common, but can lead to vision loss much more quickly. Wet AMD is characterized by new abnormal blood vessels developing under the macula, where they do not normally grow. This frequently occurs in patients who already have dry AMD, as new blood vessels are developed to try to solve the problem. It is not known what causes AMD to develop; however, certain risk factors (i.e., age, smoking, genetic factors) can increase the risk of developing AMD. There are currently no treatments for dry AMD. There is evidence that not smoking, exercising regularly, eating nutritious food, and taking certain supplements can reduce the risk of acquiring AMD or slow its development. The main treatment for wet AMD is inhibitors of VEGF (vascular endothelial growth factor), a protein that stimulates the growth of new blood vessels. VEGF inhibitors can stop the growth of new blood vessels, preventing further damage to the macula and vision loss. In most patients, VEGF inhibitors can improve vision if macular degeneration is diagnosed early and treated accordingly. However, VEGF inhibitors cannot repair damage that has already occurred. Current AMD research is trying to find treatments for dry AMD and other options for wet AMD. This review provides a summary of the current evidence regarding the different treatments aimed at both forms of AMD with particular and greater attention to the dry form.

Enhancing Ophthalmic Care: The Transformative Potential of Digital Twins in Healthcare

This literature review explores the emerging role of digital twin (DT) technology in ophthalmology, emphasizing its potential to revolutionize personalized medicine. DTs integrate diverse data sources, including genetic, environmental, and real-time patient data, to create dynamic, predictive models that enhance risk assessment, surgical planning, and postoperative care. The review highlights vital case studies demonstrating the application of DTs in improving the early detection and management of diseases such as glaucoma and age-related macular degeneration. While implementing DTs presents challenges, including data integration and privacy concerns, the potential benefits, such as improved patient outcomes and cost savings, position DTs as a valuable tool in the future of ophthalmic care. The review underscores the need for further research to address these challenges and fully realize the potential of DTs in clinical practice.

Nutritional Genomics: Implications for Age-Related Macular Degeneration

Background: Age-related macular degeneration (AMD) is a leading cause of vision loss in older individuals, driven by a multifactorial etiology involving genetic, environmental, and dietary factors. Nutritional genomics, which studies gene-nutrient interactions, has emerged as a promising field for AMD prevention and management. Genetic predispositions, such as variants in CFH, C3, C2/CFB, APOE, and oxidative stress pathways, significantly affect the risk and progression of AMD. Methods: This narrative review synthesizes findings from randomized controlled trials and recent advances in nutritional genomics research. It examines the interplay between genetic predispositions and dietary interventions, exploring how personalized nutritional strategies can optimize AMD management. Results and Discussion: The AREDS and AREDS2 trials demonstrated that supplements, including vitamins C, E, zinc, copper, lutein, and zeaxanthin, can reduce the progression to advanced AMD. Nutritional interventions tailored to genetic profiles show promise: CFH risk alleles may enhance zinc supplementation's anti-inflammatory effects, while APOE variants influence the response to omega-3 fatty acids. Adjusting carotenoid intake, such as lutein and zeaxanthin, based on genetic susceptibility exemplifies emerging precision nutritional approaches. Ongoing research seeks to integrate nutrigenomic testing into clinical settings, enabling clinicians to tailor interventions to individual genetic profiles. Conclusions: Further studies are needed to assess the long-term effects of personalized interventions, investigate additional genetic variants, and develop tools for clinical implementation of nutrigenomics. Advancing these strategies holds the potential to improve patient outcomes, optimize AMD management, and pave the way for precision nutrition in ophthalmology.

A Comprehensive Health Screening Program Reveals the Prevalence of and Risk Factors for Age-Related Macular Degeneration: A Cross-Sectional Analysis

Background/Objectives: We investigated the prevalence of age-related macular degeneration (AMD) and associated risk factors in Korean subjects who underwent comprehensive health screening examinations. Methods: This single health screening center-based cross-sectional study included a total of 73,574 consecutive participants older than 30 years who underwent a health screening examination, including fundus photography, between October 2003 and December 2010. Weighted prevalence and risk factors for AMD were evaluated. Logistic regression was used to identify AMD risk factors. Results: The weighted prevalence of AMD was 15.42%, with a prevalence of 3.34% among people in their 30s. Advanced age significantly increased the risk for both early/intermediate AMD (p < 0.001 across the age groups of 40, 50, 60, and 70+ years) and advanced AMD (p <0.001 for the age groups of 60 and 70+ years). The male sex was strongly associated with an increased risk of both early/intermediate and advanced AMD (p < 0.001 for both). Retinal arteriosclerosis, whether low- or high-grade, was linked to early/intermediate AMD (p < 0.001 for both grades), whereas only high-grade arteriosclerosis was linked to advanced AMD (p < 0.001). Additionally, hypertension (p < 0.001), the hepatitis B carrier status (p < 0.001), elevated mean corpuscular volume (p < 0.001), and lower serum uric acid levels (p = 0.014) were associated with early/intermediate AMD. Higher education levels protected against early/intermediate AMD (p = 0.004 for high school graduates, p < 0.001 for ≥college graduates). Higher serum inorganic phosphate levels (p = 0.002) and lower total serum ALB levels (p = 0.005) were significant risk factors for advanced AMD. Conclusions: Korean individuals as young as 30 years old are at risk of AMD. This study newly identified associations between retinal arteriosclerosis and both early/intermediate and advanced AMD, as well as associations between serum inorganic phosphate levels and total ALB levels with advanced AMD.

Blue Light-Induced Mitochondrial Oxidative Damage Underlay Retinal Pigment Epithelial Cell Apoptosis

Reactive oxygen species (ROS) play a pivotal role in apoptosis. We reported that Blue Light (BL) induced oxidative stress in human retinal pigment epithelial (RPE) cells in vitro and increased drusen deposition and RPE cell apoptosis in human eyes. Here, we investigated the mechanisms underlying BL-induced damage to RPE cells. Cells were exposed to BL with or without the antioxidant N-acetylcysteine. Cells were analyzed for levels of ROS, proliferation, viability, and mitochondria membrane potential (ΔΨM) fluctuation. We performed proteomic analyses to search for differentially expressed proteins. ROS levels increased following RPE cell exposure to BL. While ROS production did not affect RPE cell proliferation, it was accompanied by decreased ΔΨM and increased cell apoptosis due to the caspase cascade activation in a ROS-dependent manner. Proteomic analyses revealed that BL decreased the levels of ROS detoxifying enzymes in exposed cells. We conclude that BL-induced oxidative stress is cytotoxic to RPE cells. These findings bring new insights into the involvement of BL on RPE cell damage and its role in the progression of age-related macular degeneration. The use of antioxidants is an avenue to block or delay BL-mediated RPE cell apoptosis to counteract the disease progression.

Protective effect of zinc against A2E-induced toxicity in ARPE-19 cells: Possible involvement of lysosomal acidification

A key pathogenic mechanism of dry age-related macular degeneration (AMD) is lysosomal dysfunction in retinal pigment epithelium (RPE) cells, which results in the accumulation of lipofuscins such as A2E (N-retinylidene-N-retinylethanolamine) that further compromises lysosomal function. This vicious cycle leads to cell death and poor visual acuity. Here, we established an in vitro model of AMD by treating a human RPE cell line (ARPE-19) with A2E and examined whether raising zinc levels confers protective effects against lysosomal dysfunction and cytotoxicity. MTT assay showed that A2E induced apoptosis in ARPE-19 cells. pHrodo™ Red fluorescence staining showed that lysosomal pH increased in A2E-treated ARPE-19 cells. Treatment with a zinc ionophore (clioquinol) reduced A2E accumulation, restored lysosomal pH to the acidic range, and reduced A2E-induced cell death, all of which were reversed by the addition of a zinc chelator (TPEN). Consistent with the in vitro results, subretinal injections of A2E in mouse eyes resulted in the death of RPE cells as well as lysosomal dysfunction, all of which were reversed by co-treatment with clioquinol. Our results suggest that restoring the levels of intracellular zinc, especially in lysosomes, would be helpful in mitigating A2E-induced cytotoxic changes including lysosomal dysfunction in RPE cells in the pathogenesis of AMD.

Levodopa is associated with reduced development of new-onset geographic atrophy in patients with age-related macular degeneration

BACKGROUND

Geographic atrophy (GA) is a significant cause of vision loss in patients with age-related macular degeneration (AMD). Current treatments are limited to anti-complement drugs, which have limited efficacy to delay progression with significant risk of complications. Levodopa (L-DOPA) is a byproduct of melanin synthesis that is associated with reduced development of neovascular AMD. In this study, we determined if L-DOPA was associated with a reduced likelihood of new-onset GA.

METHODS

We performed a retrospective analysis in the Vestrum Health Retina Database. We included eyes with non-neovascular AMD without GA and 1-5 years of follow-up. Eyes were divided into two groups. Exposed to L-DOPA before or on the date of non-neovascular AMD without GA diagnosis, and eyes not exposed to L-DOPA. We extracted age, sex, AREDS2 status, dry AMD stage, smoking history, and conversion rate to GA at years 1 through 5. Propensity score matching was used to match L-DOPA and control groups. Cox proportional hazard regression, adjusting for age, sex, AMD severity, AREDS2 use, smoking status, and L-DOPA use was employed to calculate hazard ratios for new-onset GA detection.

RESULTS

We identified 112,089 control and 844 L-DOPA exposed eyes with non-neovascular AMD without GA. After propensity score matching, 2532 control and 844 L-DOPA exposed eyes remained that were well-matched for age, sex, AMD severity, AREDS2 use, and smoking status. We found that L-DOPA exposure was associated with a significantly reduced likelihood (HR = 0.68, 95% CI: 0.48-0.95, P = 0.025) of new-onset GA detection.

CONCLUSION

L-DOPA use was associated with reduced detection of new-onset GA.

Knowledge, attitudes, and practices of patients with age-related macular degeneration (AMD) towards Anti-VEGF treatment under one-stop intravitreal injection model

To evaluate the knowledge, attitudes, and practices (KAP) of patients with age-related macular degeneration (AMD) regarding anti-VEGF treatment within a one-stop intravitreal injection service model. A cross-sectional study was conducted from July 1, 2023, to January 31, 2024, at the One-stop Intravitreal Injection Center at Tianjin Medical University Eye Hospital. Data were collected using a specially designed KAP questionnaire. The study successfully enrolled 493 participants. Of these, 214 (43.4%) were aged between 70 and 79 years, and 226 (45.8%) had been diagnosed with AMD for 1-3 years. The median knowledge, attitude, and practice scores were 6.00 [3.00, 8.00] (possible range: 0-9), 42.00 [37.00, 48.00] (possible range: 11-55), and 23.00 [18.00, 27.00] (possible range: 6-30), respectively. Multivariate logistic regression for practice showed that knowledge score (OR = 1.329, P < 0.001), attitude score (OR = 1.150, P < 0.001), aged 60-69 years (OR = 0.398, P = 0.022) were independently associated with proactive practice. Mediating effect significance showed that knowledge directly affected attitude (β = 0.625), knowledge (β = 0.398) and attitude (β = 0.503) directly affected practice (P < 0.001). Meanwhile, knowledge also indirectly affected practice through attitude (β = 0.315, P < 0.001). Regarding the factors impacting their selection of anti-VEGF treatment, 63.5% of patients emphasized the crucial role of its effectiveness. Additionally, over 40% of patients considered both family circumstances and insurance coverage to be highly significant in their decision-making process. This study found that patients with AMD exhibit suboptimal knowledge yet hold positive attitudes and engage actively in practices concerning anti-VEGF treatment within a one-stop intravitreal injection service model. It is recommended that healthcare providers enhance educational interventions at intravitreal injection centers to boost patient knowledge, which is likely to further improve attitudes and proactive management practices among AMD patients.

Intravitreal Metformin Protects Against Choroidal Neovascularization and Light-Induced Retinal Degeneration

Neovascular age-related macular degeneration (nAMD), a leading cause of blindness in older adults, presents a challenging pathophysiology involving choroidal neovascularization (CNV) and retinal degeneration. Current treatments relying on intravitreal (IVT) administration of anti-angiogenic agents are costly and of moderate effectiveness. Metformin, the common anti-diabetic drug, has been associated with decreased odds of developing AMD. Studies have shown that metformin can mitigate cellular aging, neoangiogenesis, and inflammation across multiple diseases. This preclinical study assessed metformin's impact on vessel growth using choroidal explants before exploring IVT metformin's effects on laser-induced CNV and light-induced retinal degeneration in C57BL/6J and BALB/cJ mice, respectively. Metformin reduced new vessel growth in choroidal explants in a dose-dependent relationship. Following laser induction, IVT metformin suppressed CNV and decreased peripheral infiltration of IBA1+ macrophages/microglia. Furthermore, IVT metformin protected against retinal thinning in response to light-induced degeneration. IVT metformin downregulated genes in the choroid and retinal pigment epithelium which are associated with angiogenesis and inflammation, two key processes that drive nAMD progression. These findings underscore metformin's capacity as an anti-angiogenic and neuroprotective agent, demonstrating this drug's potential as an accessible option to help manage nAMD.

Can salivary and skin microbiome become a biodetector for aging-associated diseases? Current insights and future perspectives

Growth and aging are fundamental elements of human development. Aging is defined by a decrease in physiological activities and higher illness vulnerability. Affected by lifestyle, environmental, and hereditary elements, aging results in disorders including cardiovascular, musculoskeletal, and neurological diseases, which accounted for 16.1 million worldwide deaths in 2019. Stress-induced cellular senescence, caused by DNA damage, can reduce tissue regeneration and repair, promoting aging. The root cause of many age-related disorders is inflammation, encouraged by the senescence-associated secretory phenotype (SASP). Aging's metabolic changes and declining immune systems raise illness risk via promoting microbiome diversity. Stable, individual-specific skin and oral microbiomes are essential for both health and disease since dysbiosis is linked with periodontitis and eczema. Present from birth to death, the human microbiome, under the influence of diet and lifestyle, interacts symbiotically with the body. Poor dental health has been linked to Alzheimer's and Parkinson's diseases since oral microorganisms and systemic diseases have important interactions. Emphasizing the importance of microbiome health across the lifetime, this study reviews the understanding of the microbiome's role in aging-related diseases that can direct novel diagnosis and treatment approaches.

Advancements in Ocular Therapy: A Review of Emerging Drug Delivery Approaches and Pharmaceutical Technologies

Eye disorders affect a substantial portion of the global population, yet the availability of efficacious ophthalmic drug products remains limited. This can be partly ascribed to a number of factors: (1) inadequate understanding of physiological barriers, treatment strategies, drug and polymer properties, and delivery systems; (2) challenges in effectively delivering drugs to the anterior and posterior segments of the eye due to anatomical and physiological constraints; and (3) manufacturing and regulatory hurdles in ocular drug product development. The present review discusses innovative ocular delivery and treatments, encompassing implants, liposomes, nanoparticles, nanomicelles, microparticles, iontophoresis, in situ gels, contact lenses, microneedles, hydrogels, bispecific antibodies, and gene delivery strategies. Furthermore, this review also introduces advanced manufacturing technologies such as 3D printing and hot-melt extrusion (HME), aimed at improving bioavailability, reducing therapeutic dosages and side effects, facilitating the design of personalized ophthalmic dosage forms, as well as enhancing patient compliance. This comprehensive review lastly offers insights into digital healthcare, market trends, and industry and regulatory perspectives pertaining to ocular product development.

Evaluation of inflammatory hyperreflective foci and plasma EPA as diagnostic and predictive markers for age-related macular degeneration

Objectives

To detect the plasma polyunsaturated fatty acids (PUFAs) concentrations in age-related macular degeneration (AMD) patients and healthy controls. Additionally, advanced studies were conducted to investigate the relationship between PUFAs concentrations and ophthalmological characteristics, including hyperreflective foci (HRF), visual acuity, and anti-vascular endothelial growth factor (anti-VEGF) response in patients with AMD.

Methods

This prospective, single-site study recruited a total of 315 participants, consisting of 105 individuals with dry AMD (early-stage AMD group), 105 individuals with neovascular AMD (late-stage AMD group), and 105 elderly individuals without any fundus diseases (healthy controls). The levels of omega-3 and omega-6 PUFAs in plasma were detected using gas chromatography. Retinal thickness, choroidal thickness, and macular volume were quantified using optical coherence tomography angiography (OCTA) scan with a 6 × 6 mm macular area, and the amounts of HRF were analyzed with OCTA scanning data.

Results

Compared to the control group, AMD patients exhibited significantly lower plasma concentrations of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and alpha linolenic acid. HRF were observed in various retinal layers of AMD patients, particularly those with late-stage AMD. The correlation coefficient matrix and multiple linear regression models demonstrated that HRF played a crucial role in best corrected visual acuity for both early (p < 0.001) and late-stage AMD patients (p = 0.006), while EPA had an inverse effect on the logarithm of the minimum angle of resolution (logMAR) value in patients with early-stage AMD (p < 0.001). As compared to patients with good responses to anti-VEGF therapy, those with poor responses had significantly lower baseline logMAR (p < 0.001), central retina thickness (p = 0.002), macular volume (p = 0.027), HRF (p = 0.024), and plasma EPA (p < 0.001). This study used a ROC curve analysis to identify the combination of HRF and EPA as a potential biomarker for predicting the response to anti-VEGF treatment in late-stage AMD patients, with an area under the curve (AUC) value of 0.775.

Conclusions

Reduced plasma EPA was detected in AMD cases and the lower EPA concentration was related to poorer visual acuity. Additionally, the quantity of HRF combined with concentration of plasma EPA may serve as the prognostic indicator for predicting the effect of anti-VEGF treatment in late-stage AMD patients.

Label-Free Assessment of Key Biological Autofluorophores: Material Characteristics and Opportunities for Clinical Applications

Autofluorophores are endogenous fluorescent compounds that naturally occur in the intra and extracellular spaces of all tissues and organs. Most have vital biological functions - like the metabolic cofactors NAD(P)H and FAD+, as well as the structural protein collagen. Others are considered to be waste products - like lipofuscin and advanced glycation end products - which accumulate with age and are associated with cellular dysfunction. Due to their natural fluorescence, these materials have great utility for enabling non-invasive, label-free assays with direct ties to biological function. Numerous technologies, with different advantages and drawbacks, are applied to their assessment, including fluorescence lifetime imaging microscopy, hyperspectral microscopy, and flow cytometry. Here, the applications of label-free autofluorophore assessment are reviewed for clinical and health-research applications, with specific attention to biomaterials, disease detection, surgical guidance, treatment monitoring, and tissue assessment - fields that greatly benefit from non-invasive methodologies capable of continuous, in vivo characterization.

Translational Research and Therapies for Neuroprotection and Regeneration of the Optic Nerve and Retina: A Narrative Review

Most retinal and optic nerve diseases pose significant threats to vision, primarily due to irreversible retinal neuronal cell death, a permanent change, which is a critical factor in their pathogenesis. Conditions such as glaucoma, retinitis pigmentosa, diabetic retinopathy, and age-related macular degeneration are the top four leading causes of blindness among the elderly in Japan. While standard treatments-including reduction in intraocular pressure, anti-vascular endothelial growth factor therapies, and retinal photocoagulation-can partially delay disease progression, their therapeutic effects remain limited. To address these shortcomings, a range of neuroprotective and regenerative therapies, aimed at preventing retinal neuronal cell loss, have been extensively studied and increasingly integrated into clinical practice over the last two decades. Several of these neuroprotective therapies have achieved on-label usage worldwide. This narrative review introduces several neuroprotective and regenerative therapies for retinal and optic nerve diseases that have been successfully translated into clinical practice, providing foundational knowledge and success stories that serve as valuable references for researchers in the field.

Analysis of prognostic and predictive factors in neovascular age-related macular degeneration Kuopio cohort

PURPOSE

The aim of the study was to explore factors affecting the progression of neovascular age-related macular degeneration (nAMD) and identify predictive factors that can estimate the duration of intravitreal treatments.

METHODS

This retrospective real-world study included 421 nAMD patients treated at the Kuopio University Hospital during years 2007-2021. The collected data included background demographics, treatment history, visual acuity and retinal biomarker analysis. Impact of baseline factors on age at diagnosis, treatment duration, received treatment intensity and visual acuity gains were analysed.

RESULTS

Heavy smoking and high body mass index (BMI) were associated with an earlier onset, while the use of anticoagulation and anti-aggregation medication were associated with a later onset of nAMD. A low number of injections during the first year of treatment and the presence of intraretinal fluid (IRF) at baseline were associated with shorter treatment duration. Interestingly, when IRF only patients were compared to subretinal fluid (SRF) only patients, IRF patients showed higher occurrences of subretinal drusenoid deposits (43.5% vs. 15%, p = 0.04). In addition, when all patients with IRF were compared to SRF only patients, more hyperreflective foci (HRF) and complete RPE and outer retinal atrophy (cRORA; 20.7% vs. 5%, p = 0.02) were observed in patients with IRF.

CONCLUSIONS

Our results reveal that heavy smoking and high BMI are accelerating factors for earlier emergence of nAMD, while the presence of IRF results in a fast-progressing disease. More intriguingly, the link between IRF and appearance of subretinal drusenoid deposits, HRF, and increased retinal atrophy was observed.

Carbon quantum dots for the diagnosis and treatment of ophthalmic diseases

Carbon quantum dots (CQDs), an emerging nanomaterial, are gaining attention in ophthalmological applications due to their distinctive physical, chemical, and biological characteristics. For example, their inherent fluorescent capabilities offer a novel and promising alternative to conventional fluorescent dyes for ocular disease diagnostics. Furthermore, because of the excellent biocompatibility and minimal cytotoxicity, CQDs are well-suited for therapeutic applications. In addition, functionalized CQDs can effectively deliver drugs to the posterior part of the eyeball to inhibit neovascularization. This review details the use of CQDs in the management of ophthalmic diseases, including various retinal diseases, and ocular infections. While still in its initial phases within ophthalmology, the significant potential of CQDs for diagnosing and treating eye conditions is evident.

Macular neovascularization

Neovascularization of the macula, a common complication of many chorioretinal diseases such as neovascular age-related macular degeneration, polypoidal choroidal vasculopathy, and pathologic myopia, results from increased synthesis of vascular endothelial growth factor (VEGF) by the retinal pigment epithelium and/or Müller cells because of localized ischemia and inflammation. The Consensus on Neovascular AMD Nomenclature (CONAN) study group acknowledged that these vessels may originate from either the choriocapillaris or the retinal microvasculature, prompting them to propose the term 'macular neovascularization' (MNV) to include intraretinal, subretinal, and sub-pigment epithelial neovascularization localized to the macula. MNV frequently appears as a grey-green macular lesion with overlying intraretinal thickening and/or subretinal exudation, causing metamorphopsia, reduced central vision, relative central scotoma, decreased reading speed, and problems with color recognition. Multimodal imaging with optical coherence tomography (OCT), OCT angiography, dye-based angiographies, fundus autofluorescence, and multiwavelength photography help establish the diagnosis and aid in selecting an appropriate treatment. The standard of care for MNV is usually intravitreal anti-vascular endothelial growth factor injections, though thermal laser photocoagulation, verteporfin photodynamic therapy, and vitreoretinal surgery are occasionally used. We discuss the etiology and clinical features of MNV, the role of multimodal imaging in establishing the diagnosis, and the available therapeutic options.

Exploring the role of granzyme B in subretinal fibrosis of age-related macular degeneration

Age-related macular degeneration (AMD), a prevalent and progressive degenerative disease of the macula, is the leading cause of blindness in elderly individuals in developed countries. The advanced stages include neovascular AMD (nAMD), characterized by choroidal neovascularization (CNV), leading to subretinal fibrosis and permanent vision loss. Despite the efficacy of anti-vascular endothelial growth factor (VEGF) therapy in stabilizing or improving vision in nAMD, the development of subretinal fibrosis following CNV remains a significant concern. In this review, we explore multifaceted aspects of subretinal fibrosis in nAMD, focusing on its clinical manifestations, risk factors, and underlying pathophysiology. We also outline the potential sources of myofibroblast precursors and inflammatory mechanisms underlying their recruitment and transdifferentiation. Special attention is given to the potential role of mast cells in CNV and subretinal fibrosis, with a focus on putative mast cell mediators, tryptase and granzyme B. We summarize our findings on the role of GzmB in CNV and speculate how GzmB may be involved in the pathological transition from CNV to subretinal fibrosis in nAMD. Finally, we discuss the advantages and drawbacks of animal models of subretinal fibrosis and pinpoint potential therapeutic targets for subretinal fibrosis.

Identification of the CDH18 gene associated with age-related macular degeneration using weighted gene co-expression network analysis

Purpose: Age-related macular degeneration (AMD) is a chronic and progressive macular degenerative disease that culminates in a gradual deterioration of central vision. Despite its prevalence, the key biomarkers for AMD have not yet been fully elucidated. In this study, we aimed to efficiently identify biomarkers crucial for diagnosing AMD. Methods: Three datasets pertaining to retinal pigment epithelium (RPE)/choroid tissues associated with AMD were selected from the GEO database. The GSE50195 dataset was utilized to conduct weighted gene co-expression network analysis (WGCNA) for identifying module genes linked to AMD. KEGG and GO enrichment analyses were subsequently conducted on these module genes. GSE29801 and GSE135092 datasets were subjected to differential expression analysis to pinpoint the DEGs intersecting with the module genes. Subsequently, wet AMD (wAMD) and dry AMD (dAMD) mouse models were developed, from which RPE/choroid tissues were harvested to validate the hub genes via RT-qPCR and Western blot. Results: Using the WGCNA, we selected the "antiquewhite4" module (r = 0.91 and p = 7e-07), which contains a total of 325 genes. Through the intersection of module genes with DEGs, nine hub genes were identified. Pathways involved in complement and coagulation cascades, ECM-receptor interactions, unsaturated fatty acid biosynthesis, and fatty acid elongation play important roles in AMD. Notably, CDH18 demonstrated notable variance across all three datasets. Post validation using RT-qPCR experiments revealed a significant downregulation of CDH18 in both dAMD and wAMD. EGLN3 was expressed at low levels in wAMD. In dAMD, EYA2, LTB, and PODXL were significantly downregulated, whereas APOC1 was notably upregulated. Western blot confirmed that CDH18 was lowly expressed in dAMD and wAMD mouse models. Conclusion: CDH18 was identified as the key gene involved in the pathogenesis of AMD. An imbalance of the complement and coagulation cascades is a potential mechanism of AMD. This study provides a novel idea for diagnosing and treating AMD in the future.

Genetic and Epigenetic Biomarkers Linking Alzheimer's Disease and Age-Related Macular Degeneration

Alzheimer's disease (AD) represents a prominent neurodegenerative disorder (NDD), accounting for the majority of dementia cases worldwide. In addition to memory deficits, individuals with AD also experience alterations in the visual system. As the retina is an extension of the central nervous system (CNS), the loss in retinal ganglion cells manifests clinically as decreased visual acuity, narrowed visual field, and reduced contrast sensitivity. Among the extensively studied retinal disorders, age-related macular degeneration (AMD) shares numerous aging processes and risk factors with NDDs such as cognitive impairment that occurs in AD. Histopathological investigations have revealed similarities in pathological deposits found in the retina and brain of patients with AD and AMD. Cellular aging processes demonstrate similar associations with organelles and signaling pathways in retinal and brain tissues. Despite these similarities, there are distinct genetic backgrounds underlying these diseases. This review comprehensively explores the genetic similarities and differences between AMD and AD. The purpose of this review is to discuss the parallels and differences between AMD and AD in terms of pathophysiology, genetics, and epigenetics.