The Diagnosis and Treatment of Age-Related Macular Degeneration

Melatonin and Risk of Age-Related Macular Degeneration

Importance

Melatonin has been shown to oppose several processes that are known to mediate age-related macular degeneration (AMD), but whether melatonin can confer benefits against AMD remains unclear.

Objective

To examine the association between melatonin supplementation and the risk of the development or progression of AMD.

Design, Setting, and Participants

This retrospective cohort study accessed data from TriNetX, a national database of deidentified electronic medical records from both inpatient and outpatient health care organizations across the US, between December 4, 2023, and March 19, 2024. Patients aged 50 years or older, 60 years or older, and 70 years or older with no history of AMD (AMD-naive group) and with a history of nonexudative AMD (nonexudative AMD group) were queried for instances of melatonin medication codes between November 14, 2008, and November 14, 2023. Patients were then classified into either a melatonin group or a control group based on the presence of medication codes for melatonin. Propensity score matching (PSM) was performed to match the cohorts based on demographic variables, comorbidities, and nonmelatonin hypnotic medication use.

Exposure

The presence of at least 4 instances of melatonin records that each occurred at least 3 months apart.

Main Outcomes and Measures

After PSM, the melatonin and the control cohorts were compared to evaluate the risk ratios (RRs) and the 95% CIs of having an outcome. For the AMD-naive group, the outcome was defined as a new diagnosis of any AMD, whereas for the nonexudative AMD group, the outcome was progression to exudative AMD.

Results

Among 121 523 patients in the melatonin-naive group aged 50 years or older (4848 in the melatonin cohort [4580 after PSM; mean (SD) age, 68.24 (11.47) years; 2588 female (56.5%)] and 116 675 in the control cohort [4580 after PSM; mean (SD) age, 68.17 (10.63) years; 2681 female (58.5%)]), melatonin use was associated with a reduced risk of developing AMD (RR, 0.42; 95% CI, 0.28-0.62). Among 66 253 patients aged 50 years or older in the nonexudative AMD group (4350 in the melatonin cohort [4064 after PSM; mean (SD) age, 80.21 (8.78) years; 2482 female (61.1%)] and 61 903 in the control cohort [4064 patients after PSM; mean (SD) age, 80.31 (8.03) years; 2531 female (62.3%)]), melatonin was associated with a reduced risk of AMD progression to exudative AMD (RR, 0.44; 95% CI, 0.34-0.56). The results were consistent among subsets of individuals aged 60 years or older (AMD-naive cohort: RR, 0.36 [95% CI, 0.25-0.54]; nonexudative AMD cohort: RR, 0.38 [95% CI, 0.30-0.49]) and 70 years or older (AMD-naive cohort: RR, 0.35 [95% CI, 0.23-0.53]; nonexudative AMD cohort: RR, 0.40 [95% CI, 0.31-0.51]).

Conclusions and Relevance

Melatonin use was associated with a decreased risk of development and progression of AMD. Although lifestyle factors may have influenced this association, these findings provide a rationale for further research on the efficacy of using melatonin as a preventive therapy against AMD.

Challenges and opportunities of developing small-molecule therapies for age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of vision loss in senior adults. The disease can be categorized into two types: wet AMD and dry AMD. Wet AMD, also known as exudative or neovascular AMD, is less common but more severe than dry AMD and is responsible for 90% of the visual impairment caused by AMD and affects 20 million people worldwide. Current treatment options mainly involve biologics that inhibit the vascular endothelial growth factor or complement pathways. However, these treatments have limitations such as high cost, injection-related risks, and limited efficacy. Therefore, new therapeutic targets and strategies have been explored to improve the outcomes of patients with AMD. A promising approach is the use of small-molecule drugs that modulate different factors involved in AMD pathogenesis, such as tyrosine kinases and integrins. Small-molecule drugs offer advantages, such as oral administration, low cost, good penetration, and increased specificity for the treatment of wet and dry AMD. This review summarizes the current status and prospects of small-molecule drugs for the treatment of wet AMD. These advances are expected to support the development of effective and targeted treatments for patients with AMD.

Exploring gellan gum-based hydrogels for regenerating human embryonic stem cells in age-related macular degeneration therapy: A literature review

Age-related macular degeneration (AMD) is a progressive ocular disease marked by the deterioration of retinal photoreceptor cells, leading to central vision decline, predominantly affecting the elderly population worldwide. Current treatment modalities, such as anti-VEGF agents, laser therapy, and photodynamic therapy, aim to manage the condition, with emerging strategies like stem cell replacement therapy showing promise. However, challenges like immune rejection and cell survival hinder the efficacy of stem cell interventions. Regenerative medicine faces obstacles in maximizing stem cell potential due to limitations in mimicking the dynamic cues of the extracellular matrix (ECM) crucial for guiding stem cell behaviour. Innovative biomaterials like gellan gum hydrogels offer tailored microenvironments conducive to enhancing stem cell culture efficacy and tissue regeneration. Gellan gum-based hydrogels, renowned for biocompatibility and customizable mechanical properties, provide crucial support for cell viability, differentiation, and controlled release of therapeutic factors, making them an ideal platform for culturing human embryonic stem cells (hESCs). These hydrogels mimic native tissue mechanics, promoting optimal hESC differentiation while minimizing immune responses and facilitating localized delivery. This review explores the potential of Gellan Gum-Based Hydrogels in regenerative AMD therapy, emphasizing their role in enhancing hESC regeneration and addressing current status, treatment limitations, and future directions.

Real-World Outcomes of Faricimab Treatment for Neovascular Age-Related Macular Degeneration and Diabetic Macular Edema

Purpose

The purpose of this study was to assess preliminary real-world outcomes in neovascular age-related macular degeneration (nAMD) and diabetic macular edema (DME) treated with intravitreal faricimab.

Patients and Methods

This was a retrospective, observational consecutive-case real-world study of patients with nAMD or DME initiated on intravitreal faricimab between November 2022 and April 2023. Treatment-naïve patients and patients previously treated with alternate anti-vascular endothelial growth factor (anti-VEGF) agents were initiated on an intended treatment plan of four monthly faricimab injections as a loading regime. Efficacy was assessed across four treatment groups. Primary outcomes assessed for both cohorts were changes in best corrected visual acuity (BCVA) and central subfield thickness (CST) on optical coherence tomography (OCT). Secondary outcomes were alterations in OCT-defined structural features.

Results

From 127 patients, 146 eyes received at least one dose of faricimab. Mean BCVA, measured in Early Treatment of Diabetic Retinopathy Study (ETDRS) letters, from baseline to fifth visit increased from: 59.0±12.8 to 62.2±14.3 in treatment-naïve nAMD; 61.1±17.6 to 63.5±14.8 in previously-treated nAMD; 61.1±13.0 to 72.8±11.5 in treatment-naïve DME; and 60.8±14.6 to 63.3±15.6 in previously-treated DME. Mean CST reduced in all four treatment groups between initiation to final loading dose, from: 442.8±172.0µm to 305.2±117.0µm (p<0.0001) in treatment-naïve nAMD; 355.2±115.1µm to 297.9±92.54µm (p<0.0001) in previously-treated nAMD; 465.8±109.1µm to 343.1±100.3µm (p<0.0001) in treatment-naïve DME; and 492.5±133.1µm to 388.5±131.4µm (p<0.0001) in previously-treated DME.

Conclusion

Real-world outcomes showed some improvement in BCVA and CST for nAMD and DME following faricimab administration, including in patients previously treated with other anti-VEGF agents. Further work involving larger cohorts over longer periods is required to determine whether improvement is maintained, and if intervals can be extended to match those observed in clinical trials.

Sequential Fabrication of a Three-Layer Retina-like Structure

Tissue engineering is considered a promising approach to treating advanced degenerative maculopathies such as nonexudative age-related macular degeneration (AMD), the leading cause of blindness worldwide. The retina consists of several hierarchical tissue layers, each of which is supported by a layer underneath. Each of these layers has a different morphology and requires distinct conditions for proper assembly. In fact, a prerequisite step for the assembly of each of these layers is the organization of the layer underneath. Advanced retinal degeneration includes degeneration of the other retina layers, including the choroid, the retinal pigmented epithelium (RPE), and the photoreceptors. Here, we report a step-by-step fabrication process of a three-layer retina-like structure. The process included the 3D printing of a choroid-like structure in an extracellular matrix (ECM) hydrogel, followed by deposition of the RPE monolayer. After the formation of the blood vessel-RPE interface, the photoreceptor cells were deposited to interact with the RPE layer. At the end of the fabrication process, each layer was characterized for its morphology and expression of specific markers, and the integration of the three-layer retina was evaluated. We envision that such a retina-like structure may be able to attenuate the deterioration of a degenerated retina and improve engraftment and regeneration. This retinal implant may potentially be suitable for a spectrum of macular degenerative diseases for which there are currently no cures and may save millions from complete blindness.

Association between ambient air pollution and age-related macular degeneration: a meta-analysis

BACKGROUND

Several epidemiological studies have investigated the association between ambient air pollution and age-related macular degeneration (AMD). However, a consensus has not yet been reached. Our meta-analysis aimed to clarify this association.

METHODS

Databases, including PubMed, EMBASE, and Web of Science, were searched for relevant studies from 01 January 2000 to 30 January 2024. English-language, peer-reviewed studies using cross-sectional, prospective, or retrospective cohorts and case-control studies exploring this relationship were included. Two authors independently extracted data and assessed study quality. A random-effects model was used to calculate pooled covariate-adjusted odds ratios. Heterogeneity across studies was also tested.

RESULTS

We identified 358 relevant studies, of which eight were included in the meta-analysis. Four studies evaluated the association between particulate matter less than 2.5 μm in diameter (PM2.5) and AMD, and three studies explored the relationship between nitrogen dioxide (NO2) or ozone (O3) and AMD. The pooled odds ratios were 1.16 (95% confidence interval [CI]: 1.11-1.21), 1.17 (95% CI: 1.09-1.25), and 1.06 (95% CI: 1.05-1.07), respectively.

CONCLUSION

Current evidence suggests a concomitant positive but not causal relationship between PM2.5, NO2, or O3 and AMD risk.

An overview of retinal light damage models for preclinical studies on age-related macular degeneration: identifying molecular hallmarks and therapeutic targets

Age-related macular degeneration (AMD) is a complex, multifactorial disease leading to progressive and irreversible retinal degeneration, whose pathogenesis has not been fully elucidated yet. Due to the complexity and to the multiple features of the disease, many efforts have been made to develop animal models which faithfully reproduce the overall AMD hallmarks or that are able to mimic the different AMD stages. In this context, light damage (LD) rodent models of AMD represent a suitable and reliable approach to mimic the different AMD forms (dry, wet and geographic atrophy) while maintaining the time-dependent progression of the disease. In this review, we comprehensively reported how the LD paradigms reproduce the main features of human AMD. We discuss the capability of these models to broaden the knowledge in AMD research, with a focus on the mechanisms and the molecular hallmarks underlying the pathogenesis of the disease. We also critically revise the remaining challenges and future directions for the use of LD models.

Epidemiology of Diagnosed Age-related Macular Degeneration in Germany: An Evaluation of the Prevalence Using AOK PLUS Claims Data

INTRODUCTION

Epidemiologic data on age-related macular degeneration (AMD) are mainly based on cohort studies, including both diagnosed and undiagnosed cases. Using health claims data allows estimating epidemiological data of diagnosed subjects with AMD within the health care system using diagnosis codes from a regional claims database (AOK PLUS) to estimate the prevalence and incidence of non-exudative and exudative AMD in Germany.

METHODS

Patients with AMD were identified among AOK PLUS insured patients based on at least two outpatient, ophthalmologic or one inpatient H35.3 diagnoses for the years 2012 to 2021. Patients without continuous observation in a calendar year were excluded. Prevalence was assessed, and 1-year cumulative incidence was determined by the number of newly diagnosed patients divided by the number of individuals at risk. For 2020 and 2021, the AMD stage was assessed by diagnostic subcodes for non-exudative and exudative AMD, respectively. For 2012 to 2019, patient numbers were estimated based on the average proportions of non-exudative AMD and exudative AMD, respectively, in 2020 and 2021. Incidence and prevalence numbers were then extrapolated to Germany.

RESULTS

Between 2012 to 2021, the prevalence of diagnosed AMD cases remained relatively stable among approximately 3.27 million AOK PLUS insured persons, ranging from 0.96% (minimum in 2021) to 1.31% (maximum in 2014) for non-exudative AMD, about twice as high as for exudative AMD (min-max: 0.53-0.72%). The age- and sex-adjusted projections amounted to 644,153 diagnosed non-exudative and 367,086 diagnosed German patients with exudative AMDs in 2021. The 1-year cumulative incidence for non-exudative and exudative AMD, respectively, ranged from 122,427-142,932 to 46,092-86,785 newly diagnosed cases.

CONCLUSION

The number of diagnosed cases with AMD in Germany has increased slightly over the past decade. For the first time, patient counts with non-exudative and exudative AMD were approximated for Germany based on a representative, large-scale database study.

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.

Progress in clinical research and applications of retinal vessel quantification technology based on fundus imaging

Retinal blood vessels are the only directly observed blood vessels in the body; changes in them can help effective assess the occurrence and development of ocular and systemic diseases. The specificity and efficiency of retinal vessel quantification technology has improved with the advancement of retinal imaging technologies and artificial intelligence (AI) algorithms; it has garnered attention in clinical research and applications for the diagnosis and treatment of common eye and related systemic diseases. A few articles have reviewed this topic; however, a summary of recent research progress in the field is still needed. This article aimed to provide a comprehensive review of the research and applications of retinal vessel quantification technology in ocular and systemic diseases, which could update clinicians and researchers on the recent progress in this field.

Translating color fundus photography to indocyanine green angiography using deep-learning for age-related macular degeneration screening

Age-related macular degeneration (AMD) is the leading cause of central vision impairment among the elderly. Effective and accurate AMD screening tools are urgently needed. Indocyanine green angiography (ICGA) is a well-established technique for detecting chorioretinal diseases, but its invasive nature and potential risks impede its routine clinical application. Here, we innovatively developed a deep-learning model capable of generating realistic ICGA images from color fundus photography (CF) using generative adversarial networks (GANs) and evaluated its performance in AMD classification. The model was developed with 99,002 CF-ICGA pairs from a tertiary center. The quality of the generated ICGA images underwent objective evaluation using mean absolute error (MAE), peak signal-to-noise ratio (PSNR), structural similarity measures (SSIM), etc., and subjective evaluation by two experienced ophthalmologists. The model generated realistic early, mid and late-phase ICGA images, with SSIM spanned from 0.57 to 0.65. The subjective quality scores ranged from 1.46 to 2.74 on the five-point scale (1 refers to the real ICGA image quality, Kappa 0.79-0.84). Moreover, we assessed the application of translated ICGA images in AMD screening on an external dataset (n = 13887) by calculating area under the ROC curve (AUC) in classifying AMD. Combining generated ICGA with real CF images improved the accuracy of AMD classification with AUC increased from 0.93 to 0.97 (P < 0.001). These results suggested that CF-to-ICGA translation can serve as a cross-modal data augmentation method to address the data hunger often encountered in deep-learning research, and as a promising add-on for population-based AMD screening. Real-world validation is warranted before clinical usage.

High-accuracy 3D segmentation of wet age-related macular degeneration via multi-scale and cross-channel feature extraction and channel attention

Wet age-related macular degeneration (AMD) is the leading cause of visual impairment and vision loss in the elderly, and optical coherence tomography (OCT) enables revolving biotissue three-dimensional micro-structure widely used to diagnose and monitor wet AMD lesions. Many wet AMD segmentation methods based on deep learning have achieved good results, but these segmentation results are two-dimensional, and cannot take full advantage of OCT's three-dimensional (3D) imaging characteristics. Here we propose a novel deep-learning network characterizing multi-scale and cross-channel feature extraction and channel attention to obtain high-accuracy 3D segmentation results of wet AMD lesions and show the 3D specific morphology, a task unattainable with traditional two-dimensional segmentation. This probably helps to understand the ophthalmologic disease and provides great convenience for the clinical diagnosis and treatment of wet AMD.

A concentrated machine learning-based classification system for age-related macular degeneration (AMD) diagnosis using fundus images

The increase in eye disorders among older individuals has raised concerns, necessitating early detection through regular eye examinations. Age-related macular degeneration (AMD), a prevalent condition in individuals over 45, is a leading cause of vision impairment in the elderly. This paper presents a comprehensive computer-aided diagnosis (CAD) framework to categorize fundus images into geographic atrophy (GA), intermediate AMD, normal, and wet AMD categories. This is crucial for early detection and precise diagnosis of age-related macular degeneration (AMD), enabling timely intervention and personalized treatment strategies. We have developed a novel system that extracts both local and global appearance markers from fundus images. These markers are obtained from the entire retina and iso-regions aligned with the optical disc. Applying weighted majority voting on the best classifiers improves performance, resulting in an accuracy of 96.85%, sensitivity of 93.72%, specificity of 97.89%, precision of 93.86%, F1 of 93.72%, ROC of 95.85%, balanced accuracy of 95.81%, and weighted sum of 95.38%. This system not only achieves high accuracy but also provides a detailed assessment of the severity of each retinal region. This approach ensures that the final diagnosis aligns with the physician's understanding of AMD, aiding them in ongoing treatment and follow-up for AMD patients.

Dysregulation of histone deacetylases in ocular diseases

Ocular diseases are a growing global concern and have a significant impact on the quality of life. Cataracts, glaucoma, age-related macular degeneration, and diabetic retinopathy are the most prevalent ocular diseases. Their prevalence and the global market size are also increasing. However, the available pharmacotherapy is currently limited. These diseases share common pathophysiological features, including neovascularization, inflammation, and/or neurodegeneration. Histone deacetylases (HDACs) are a class of enzymes that catalyze the removal of acetyl groups from lysine residues of histone and nonhistone proteins. HDACs are crucial for regulating various cellular processes, such as gene expression, protein stability, localization, and function. They have also been studied in various research fields, including cancer, inflammatory diseases, neurological disorders, and vascular diseases. Our study aimed to investigate the relationship between HDACs and ocular diseases, to identify a new strategy for pharmacotherapy. This review article explores the role of HDACs in ocular diseases, specifically focusing on diabetic retinopathy, age-related macular degeneration, and retinopathy of prematurity, as well as optic nerve disorders, such as glaucoma and optic neuropathy. Additionally, we explore the interplay between HDACs and key regulators of fibrosis and angiogenesis, such as TGF-β and VEGF, highlighting the potential of targeting HDAC as novel therapeutic strategies for ocular diseases.

Minocycline and Diacetyl Minocycline Eye Drops Reduce Ocular Neovascularization in Mice

Purpose

To evaluate the efficacy of minocycline and a novel, modified minocycline analogue that lacks antimicrobial action, diacetyl minocycline (DAM), on choroidal neovascularization (CNV) in mice of both sexes.

Methods

CNV was induced via laser injury in female and male C57BL/6J mice. Minocycline, DAM, or saline was administered via topical eye drops twice a day for 2 weeks starting the day after laser injury. CNV volume was measured using immunohistochemistry labeling and confocal microscopy.

Results

Minocycline reduced lesion volume by 79% (P ≤ 0.0004) in female and male mice. DAM reduced lesion volume by 73% (P ≤ 0.001) in female and male mice. There was no significant difference in lesion volume between minocycline and DAM treatment groups or between female and male mice.

Conclusions

Both minocycline and DAM eye drops significantly reduced laser-induced CNV lesion volume in female and male mice. While oral tetracyclines have been shown to mitigate pathologic neovascularization in both preclinical studies and clinical trials, the present data are the first to suggest that tetracycline derivatives may be effective to reduce pathologic CNV when administered via topical eye drops. However, the action is unrelated to antimicrobial action. Targeted delivery of these medications via eye drops may reduce the potential for systemic side effects.

Translational Relevance

Topical administration of minocycline and/or DAM via eye drops may represent a novel therapeutic strategy for disorders involving pathologic CNV.

Cigarette smoke causes a bioenergetic crisis in RPE cells involving the downregulation of HIF-1α under normoxia

Age-related macular degeneration (AMD) is the most common blinding disease in the elderly population. However, there are still many uncertainties regarding the pathophysiology at the molecular level. Currently, impaired energy metabolism in retinal pigment epithelium (RPE) cells is discussed as one major hallmark of early AMD pathophysiology. Hypoxia-inducible factors (HIFs) are important modulators of mitochondrial function. Moreover, smoking is the most important modifiable risk factor for AMD and is known to impair mitochondrial integrity. Therefore, our aim was to establish a cell-based assay that enables us to investigate how smoking affects mitochondrial function in conjunction with HIF signaling in RPE cells. For this purpose, we treated a human RPE cell line with cigarette smoke extract (CSE) under normoxia (21% O2), hypoxia (1% O2), or by co-treatment with Roxadustat, a clinically approved HIF stabilizer. CSE treatment impaired mitochondrial integrity, involving increased mitochondrial reactive oxygen species, disruption of mitochondrial membrane potential, and altered mitochondrial morphology. Treatment effects on cell metabolism were analyzed using a Seahorse Bioanalyzer. Mitochondrial respiration and ATP production were impaired in CSE-treated cells under normoxia. Surprisingly, CSE-treated RPE cells also exhibited decreased glycolytic rate under normoxia, causing a bioenergetic crisis, because two major metabolic pathways that provide ATP were impaired by CSE. Downregulation of glycolytic rate was HIF-dependent because HIF-1α, the α-subunit of HIF-1, was downregulated by CSE on the protein level, especially under normoxia. Moreover, hypoxia incubation and treatment with Roxadustat restored glycolytic flux. Taken together, our in vitro model provides interesting insights into HIF-dependent regulation of glycolysis under normoxic conditions, which will enable us to investigate signaling pathways involved in RPE metabolism in health and disease.

Chimpanzee adenovirus-mediated multiple gene therapy for age-related macular degeneration

Neovascular age-related macular degeneration AMD (nAMD) is characterized by choroidal neovascularization (CNV) and could lead to irreversible blindness. However, anti-vascular endothelial growth factor (VEGF) therapy has limited efficacy. Therefore, we generated a chimpanzee adenoviral vector (AdC68-PFC) containing three genes, pigment endothelial-derived factor (PEDF), soluble fms-like tyrosine kinase-1 (sFlt-1), and soluble forms of CD59 (sCD59), to treat nAMD. The results showed that AdC68-PFC mediated a strong onset of PEDF, sFlt-1, and sCD59 expression both in vivo and in vitro. AdC68-PFC showed preventive and therapeutic effects following intravitreal (IVT) injection in the laser-induced CNV model and very low-density lipoprotein receptor-deficient (Vldlr-/-) mouse model. In vitro assessment indicated that AdC68-PFC had a strong inhibitory effect on endothelial cells. Importantly, the safety test showed no evidence of in vivo toxicity of adenovirus in murine eyes. Our findings suggest that AdC68-PFC may be a long-acting and safe gene therapy vector for future nAMD treatments.

A treatment within sight: challenges in the development of stem cell-derived photoreceptor therapies for retinal degenerative diseases

Stem cell therapies can potentially treat various retinal degenerative diseases, including age-related macular degeneration (AMD) and inherited retinal diseases like retinitis pigmentosa. For these diseases, transplanted cells may include stem cell-derived retinal pigmented epithelial (RPE) cells, photoreceptors, or a combination of both. Although stem cell-derived RPE cells have progressed to human clinical trials, therapies using photoreceptors and other retinal cell types are lagging. In this review, we discuss the potential use of human pluripotent stem cell (hPSC)-derived photoreceptors for the treatment of retinal degeneration and highlight the progress and challenges for their efficient production and clinical application in regenerative medicine.

Age-Related Macular Degeneration in an Ageing Society - Current Epidemiological Research

Epidemiological studies on age-related macular degeneration (AMD) provide crucial data on the frequency of early and late forms as well as associated risk factors. The increasing number of population-based cross-sectional and longitudinal cohort studies in Germany and Europe with published data is making prevalence and incidence estimators for AMD more robust, although they show mostly method-related fluctuations. This review article brings together the latest published epidemiological measures for AMD from Germany and Central as well as Western Europe. Based on this data and population figures for Germany and Europe, prevalence is projected, and future trends are forecasted. The epidemiological evidence for AMD-associated risk factors is also improving, especially through meta-analyses within large consortia with correspondingly high case numbers. This review article summarizes the latest findings and resulting recommendations for prevention approaches. Additionally, it discusses treatment options and future challenges.

Circulating MicroRNAs as Biomarker for Vessel-Associated Retinal Diseases

INTRODUCTION

Vessel-associated retinal diseases are a major cause of blindness and severe visual impairment. The identification of appropriate biomarkers is of great importance to better anticipate disease progression and establish more targeted treatment options. MicroRNAs (miRNAs) are short, single-stranded, noncoding ribonucleic acids that are involved in the posttranscriptional regulation of gene expression through hybridization with messenger RNA. The expression of certain miRNAs can be different in patients with pathological processes and can be used for the detection and differentiation of various diseases. In this study, we investigate to what extent previously in vitro identified miRNAs are present as cell-free circulating miRNAs in the serum and vitreous of human patients with and without vessel-associated retinal diseases.

METHODS

Relative quantification by quantitative real-time polymerase chain reaction was used to analyze miRNA expression in patients with vessel-associated retinal diseases such as age-related macular degeneration (AMD), diabetic retinopathy (DR), and retinal vein occlusion compared with control patients.

RESULTS

In serum samples, miR-29a-3p and miR-192-5p showed increased expression in patients with neovascular AMD relative to control patients. Similarly, miR-335-5p, miR-192-5p, and miR-194-5p showed increased expression in serum from patients with proliferative DR. In vitreous samples, miR-100-5p was decreased in patients with proliferative DR. Differentially expressed miRNAs showed good diagnostic accuracy in receiver operating characteristic (ROC) and area under the ROC curve analysis.

CONCLUSION

The miRNAs investigated in this study may have the potential to serve as biomarkers for vessel-associated retinal diseases. Combining multiple miRNAs may enhance the predictive power of the analysis.

Electrochemical nano-biosensor based on electrospun indium zinc oxide nanofibers for the determination of complement component 3 protein

Age-related macular degeneration (AMD) is a progressive chronic neurodegenerative retinal disease leading to vision loss, irreversible blindness, and visual impairment in older adults worldwide. Complement component 3 (C3) protein has been identified as the most predominant biomarker towards early diagnosis of AMD; therefore, there is an utmost requirement for non-invasive detection of C3 protein in the tear fluids of AMD patients. Considering this, we report an insightful electrochemical sensor capable of detecting clinically relevant concentrations ranging from 10 fg/mL to 1 μg/mL using electrospun indium-doped zinc oxide (InZnO) nanofibers as the transducing layer. The InZnO nanofibers have facilitated high anti-C3 antibody loading of 3.42 × 10^-9 mol/cm² and enhanced the overall charge transport mechanism at the sensor interface. The biofunctionalization process of the biosensor was investigated thoroughly using X-ray photoelectron spectroscopy (XPS) as well as different electrochemical techniques. The target C3 proteins were captured on the fabricated biosensor surface and determined through changes in charge transfer resistance (R_CT) while executing electrochemical impedance spectroscopy (EIS) and peak current (I_p) in the case of cyclic voltammetry (CV) and differential pulse voltammetry (DPV), respectively. The InZnO nanofiber-based nano-biosensor demonstrated a very low limit of detections (LODs) of 5.214 fg/mL and 0.241 fg/mL with an excellent sensitivity of 4.6709 (ΔR/R) (g/mL)^-1 cm^-2 and 54.4939 (ΔI_p/I_p)% (g/mL)^-1 cm^-2 for EIS and DPV techniques, respectively. By virtue of high antibody loading, ultrasensitive and ultra-selective capability, the indium-doped ZnO nanofibers show huge potential to be used as a high-performance diagnostic platform for AMD diagnosis.

Purinergic signaling via P2X receptors and mechanisms of unregulated ATP release in the outer retina and age-related macular degeneration

Age-related macular degeneration (AMD) is a chronic and progressive inflammatory disease of the retina characterized by photoceptor loss and significant central visual impairment due to either choroidal neovascularization or geographic atrophy. The pathophysiology of AMD is complex and multifactorial, driven by a combination of modifiable and non-modifiable risk factors, molecular mechanisms, and cellular processes that contribute to overall disease onset, severity, and progression. Unfortunately, due to the structural, cellular, and pathophysiologic complexity, therapeutic discovery is challenging. While purinergic signaling has been investigated for its role in the development and treatment of ocular pathologies including AMD, the potential crosstalk between known contributors to AMD, such as the complement cascade and inflammasome activation, and other biological systems, such as purinergic signaling, have not been fully characterized. In this review, we explore the interactions between purinergic signaling, ATP release, and known contributors to AMD pathogenesis including complement dysregulation and inflammasome activation. We begin by identifying what is known about purinergic receptors in cell populations of the outer retina and potential sources of extracellular ATP required to trigger purinergic receptor activation. Next, we examine evidence in the literature that the purinergic system accelerates AMD pathogenesis leading to apoptotic and pyroptotic cell death in retinal cells. To fully understand the potential role that purinergic signaling plays in AMD, more research is needed surrounding the expression, distribution, functions, and interactions of purinergic receptors within cells of the outer retina as well as potential crosstalk with other systems. By determining how these processes are affected in the context of purinergic signaling, it will improve our understanding of the mechanisms that drive AMD pathogenesis which is critical in developing treatment strategies that prevent or slow progression of the disease.

Deep Learning Classification of Drusen, Choroidal Neovascularization, and Diabetic Macular Edema in Optical Coherence Tomography (OCT) Images

Background Age-related macular degeneration (AMD), diabetic retinopathy (DR), drusen, choroidal neovascularization (CNV), and diabetic macular edema (DME) are significant causes of visual impairment globally. Optical coherence tomography (OCT) imaging has emerged as a valuable diagnostic tool for these ocular conditions. However, subjective interpretation and inter-observer variability highlight the need for standardized diagnostic approaches. Methods This study aimed to develop a robust deep learning model using artificial intelligence (AI) techniques for the automated detection of drusen, CNV, and DME in OCT images. A diverse dataset of 1,528 OCT images from Kaggle.com was used for model training. The performance metrics, including precision, recall, sensitivity, specificity, F1 score, and overall accuracy, were assessed to evaluate the model's effectiveness. Results The developed model achieved high precision (0.99), recall (0.962), sensitivity (0.985), specificity (0.987), F1 score (0.971), and overall accuracy (0.987) in classifying diseased and healthy OCT images. These results demonstrate the efficacy and efficiency of the model in distinguishing between retinal pathologies. Conclusion The study concludes that the developed deep learning model using AI techniques is highly effective in the automated detection of drusen, CNV, and DME in OCT images. Further validation studies and research efforts are necessary to evaluate the generalizability and integration of the model into clinical practice. Collaboration between clinicians, policymakers, and researchers is essential for advancing diagnostic tools and management strategies for AMD and DR. Integrating this technology into clinical workflows can positively impact patient care, particularly in settings with limited access to ophthalmologists. Future research should focus on collecting independent datasets, addressing potential biases, and assessing real-world effectiveness. Overall, the use of machine learning algorithms in conjunction with OCT imaging holds great potential for improving the detection and management of drusen, CNV, and DME, leading to enhanced patient outcomes and vision preservation.

Combinations of Photodynamic Therapy with Other Minimally Invasive Therapeutic Technologies against Cancer and Microbial Infections

The rapid rise in research and development following the discovery of photodynamic therapy to establish novel photosensitizers and overcome the limitations of the technology soon after its clinical translation has given rise to a few significant milestones. These include several novel generations of photosensitizers, the widening of the scope of applications, leveraging of the offerings of nanotechnology for greater efficacy, selectivity for the disease over host tissue and cells, the advent of combination therapies with other similarly minimally invasive therapeutic technologies, the use of stimulus-responsive delivery and disease targeting, and greater penetration depth of the activation energy. Brought together, all these milestones have contributed to the significant enhancement of what is still arguably a novel technology. Yet the major applications of photodynamic therapy still remain firmly located in neoplasms, from where most of the new innovations appear to launch to other areas, such as microbial, fungal, viral, acne, wet age-related macular degeneration, atherosclerosis, psoriasis, environmental sanitization, pest control, and dermatology. Three main value propositions of combinations of photodynamic therapy include the synergistic and additive enhancement of efficacy, the relatively low emergence of resistance and its rapid development as a targeted and high-precision therapy. Combinations with established methods such as chemotherapy and radiotherapy and demonstrated applications in mop-up surgery promise to enhance these top three clinical tools. From published in vitro and preclinical studies, clinical trials and applications, and postclinical case studies, seven combinations with photodynamic therapy have become prominent research interests because they are potentially easily applied, showing enhanced efficacy, and are rapidly translating to the clinic. These include combinations with chemotherapy, photothermal therapy, magnetic hyperthermia, cold plasma therapy, sonodynamic therapy, immunotherapy, and radiotherapy. Photochemical internalization is a critical mechanism for some combinations.

Polypharmacology: promises and new drugs in 2022

Polypharmacology is an emerging strategy of design, synthesis, and clinical implementation of pharmaceutical agents that act on multiple targets simultaneously. It should not be mixed up with polytherapy, which is based on the use of multiple selective drugs and is considered a cornerstone of current clinical practice. However, this 'classic' approach, when facing urgent medical challenges, such as multifactorial diseases, increasing resistance to pharmacotherapy, and multimorbidity, seems to be insufficient. The 'novel' polypharmacology concept leads to a more predictable pharmacokinetic profile of multi-target-directed ligands (MTDLs), giving a chance to avoid drug-drug interactions and improve patient compliance due to the simplification of dosing regimens. Plenty of recently marketed drugs interact with multiple biological targets or disease pathways. Many offer a significant additional benefit compared to the standard treatment regimens. In this paper, we will briefly outline the genesis of polypharmacology and its differences to polytherapy. We will also present leading concepts for obtaining MTDLs. Subsequently, we will describe some successfully marketed drugs, the mechanisms of action of which are based on the interaction with multiple targets. To get an idea, of whether MTDLs are indeed important in contemporary pharmacology, we also carefully analyzed drugs approved in 2022 in Germany: 10 out of them were found multi-targeting, including 7 antitumor agents, 1 antidepressant, 1 hypnotic, and 1 drug indicated for eye disease.

Recent advances of exosomes in age-related macular degeneration

Exosomes are 30-150 nm extracellular vesicles that are secreted by almost all types of cells. Exosomes contain a variety of biologically active substances, such as proteins, nucleic acids, and lipids, and are important in the intercellular communication of biological mediators involved in nerve injury and repair, vascular regeneration, immune response, fibrosis formation, and many other pathophysiological processes. Although it has been extensively studied in the field of cancer, the exploration of ocular diseases has only just begun. Here, we discuss the latest developments in exosomes for age-related macular degeneration (AMD), including the pathogenesis of exosomes in age-related macular degeneration, their potential as diagnostic markers, and therapeutic vectors of the disease. Finally, the study of exosomes in age-related macular degeneration is still relatively few, and more detailed basic research and clinical trials are needed to verify its application in treatment and diagnosis, so as to adopt more personalized diagnosis and treatment strategies to stop the progression of age-related macular degeneration.

In-depth mining of single-cell transcriptome reveals the key immune-regulated loops in age-related macular degeneration

Introduction

Age-related macular degeneration (AMD), an ever-increasing ocular disease, has become one of the leading causes of irreversible blindness. Recent advances in single-cell genomics are improving our understanding of the molecular mechanisms of AMD. However, the pathophysiology of this multifactorial disease is complicated and still an ongoing challenge. To better understand disease pathogenesis and identify effective targets, we conducted an in-depth analysis of the single-cell transcriptome of AMD.

Methods

The cell expression specificity of the gene (CESG) was selected as an index to identify the novel cell markers. A computational framework was designed to explore the cell-specific TF regulatory loops, containing the interaction of gene pattern signatures, transcription factors regulons, and differentially expressed genes.

Results

Three potential novel cell markers were DNASE1L3 for endothelial cells, ABCB5 for melanocytes, and SLC39A12 for RPE cells detected. We observed a notable change in the cell abundance and crosstalk of fibroblasts cells, melanocytes, schwann cells, and T/NK cells between AMD and controls, representing a complex cellular ecosystem in disease status. Finally, we identified six cell type related and three disease-associated ternary loops and elaborated on the robust association between key immune-pathway and AMD.

Discussion

In conclusion, this study facilitates the optimization of screening for AMD-related receptor ligand pathways and proposes to further improve the interpretability of disease associations from single-cell data. It illuminated that immune-related regulation paths could be used as potential diagnostic markers for AMD, and in the future, also as therapeutic targets, providing insights into AMD diagnosis and potential interventions.

Age-Related Macular Degeneration: An Exponentially Emerging Imminent Threat of Visual Impairment and Irreversible Blindness

Age-related macular degeneration (AMD) is a significant cause of blindness globally. With the exponential rise in the aging population, AMD is the third leading cause of visual impairment worldwide. Neovascular AMD (nAMD; Wet AMD) and geographical atrophy (GA, late-stage dry AMD) are the advanced AMD accountable for substantial cases of visual deterioration among the elderly. Our review of the literature depicted that notable risk factors include cigarette smoking, nutritional elements, cardiovascular disorders, and genetic markers, including genes regulating complement, lipid, and angiogenic pathways. Some studies have suggested a relative decline in the proportion of AMD cases in the last two decades attributable to novel diagnostic and therapeutic modalities. Accurate diagnosis is the result of a combination of clinical examination and imaging techniques, including retinal photography, angiography, and optical coherence tomography. The incorporation of dietary antioxidant supplements, explicitly lutein, slows the progression of the disease in advanced stages. The induction of vascular endothelial growth factor (VEGF) inhibitors in the treatment of neovascular AMD, often combined with other modalities, has shown an immensely favorable prognosis. Research to integrate gene therapy and regenerative techniques using stem cells is underway to further mitigate AMD-associated morbidity. It is imperative to establish screening and therapeutic guidelines for AMD to curtail the future social and financial burden and improve the diminishing quality of life among the elderly.

Comparison of vegetable oils on the uptake of lutein and zeaxanthin by ARPE-19 cells

AIM

To compare the effect of vegetable oils on the uptake of lutein and zeaxanthin by adult retinal pigment epithelial (ARPE)-19 cells in vitro.

METHODS

ARPE-19 cells were cultured in Dulbecco's Modified Eagle Medium-F-12 supplemented with 10% foetal bovine serum and 1% penicillin-streptomycin in a humidified 5% CO₂ incubator maintained at 37°C. Cells were treated with 247 µmol/L lutein, 49 µmol/L zeaxanthin and 1% (v/v) of either coconut oil, corn oil, peanut oil, olive oil, sunflower oil, soybean oil, castor oil, or linseed oil for 48h. Lutein and zeaxanthin concentration in the cells were quantified by high performance liquid chromatography.

RESULTS

Among the oils tested, the highest lutein and zeaxanthin uptake was observed with coconut oil while the lowest was observed with linseed oil.

CONCLUSION

ARPE-19 uptake of lutein and zeaxanthin are found to be dependent on the type of oils.

Reverse engineering for reconstructing baseline features of dry age-related macular degeneration in optical coherence tomography

Age-related macular degeneration (AMD) is the most widespread cause of blindness and the identification of baseline AMD features or biomarkers is critical for early intervention. Optical coherence tomography (OCT) imaging produces a 3D volume consisting of cross sections of retinal tissue while fundus fluorescence (FAF) imaging produces a 2D mapping of retina. FAF has been a good standard for assessing dry AMD late-stage geographic atrophy (GA) while OCT has been used for assessing early AMD biomarkers beyond as well. However, previous approaches in large extent defined AMD features subjectively based on clinicians' observation. Deep learning-an objective artificial intelligence approach, may enable to discover 'true' salient AMD features. We develop a novel reverse engineering approach which bases on the backbone of a fully convolutional neural network to objectively identify and visualize AMD early biomarkers in OCT from baseline exams before significant atrophy occurs. Utilizing manually annotated GA regions on FAF from a follow-up visit as ground truth, we segment GA regions and reconstruct early AMD features in baseline OCT volumes. In this preliminary exploration, compared with ground truth, we achieve baseline GA segmentation accuracy of 0.95 and overlapping ratio of 0.65. The reconstructions consistently highlight that large druse and druse clusters with or without mixed hyper-reflective focus lesion on baseline OCT cause the conversion of GA after 12 months. However, hyper-reflective focus lesions and subretinal drusenoid deposit lesions alone are not seen such conversion after 12 months. Further research with larger dataset would be needed to verify these findings.

A hypothetical therapeutic effect of light peripheral panretinal photocoagulation in neovascular age-related macular degeneration

Background

Vascular endothelial growth factor (VEGF) is a significant modulator of ocular angiogenesis, including that of neovascular age-related macular degeneration (nAMD). Intravitreal injection of anti-VEGF is the benchmark treatment for most retinal vascular diseases, including nAMD, diabetic maculopathy, and macular edema secondary to retinal venous occlusion. Anti-VEGF treatment is a high-frequency, time-consuming, non-cost-effective therapy, especially in countries and regions with limited resources. This treatment is easily restricted, and in practice, maintaining long-term periodic care is challenging for patients.

Hypothesis

Light peripheral panretinal photocoagulation (PPRP) is applied in a mild form (barely visible mild light gray mark) anterior to the equator so as not to jeopardize the visual field. PPRP lessens the ischemia that causes neovascularization and decreases the metabolic demand in the peripheral retina. PPRP reduces serum angiopoietin-2 and VEGF levels in patients with type 2 diabetes mellitus with proliferative diabetic retinopathy. We propose using light PPRP to suppress VEGF secretion, aiming to attenuate the VEGF drive and halt choroidal neovascular growth in eyes with nAMD. Our regimen is based on two concepts: first, nAMD is a diffuse or generalized disease that affects the posterior segment; and second, PPRP is very effective in regressing diabetic retinopathy. PPRP has reportedly been successful in cases of macular edema (diabetic or following venous occlusion) resistant to VEGF antagonists. Light PPRP may be used as prophylaxis, adjunctive treatment, or monotherapy in nAMD when intravitreal injections of VEGF antagonists are not feasible.

Conclusions

The established light PPRP therapy could be promising as a one-time, cost-effective therapy or prophylaxis in patients with nAMD or at high risk. This proposed modality could be suitable for patients who have injection phobia or prefer a one-time affordable therapy to the long-term monthly visits to retinologists. Future trials are necessary to verify the safety and efficacy of this proposed treatment modality in selected patients with nAMD.

The Effect of Dietary Supplementations on Delaying the Progression of Age-Related Macular Degeneration: A Systematic Review and Meta-Analysis

Purpose: Age-related macular degeneration (AMD) is a neurodegenerative ophthalmic disease. The purpose of this systematic review (SR) and meta-analysis was to evaluate if dietary supplementation alone or in combinations might delay the progression of any of the stages of AMD. Methods: A SR and meta-analysis identifying cohort studies and randomized controlled trials (RCTs) evaluating the effect of supplements in patients diagnosed with AMD. PubMed, Scopus, Web of Science, CINHAL, and Cochrane were searched through 8th October 2021. Results: Twenty studies, examining 5634 participants ranging from 55 to 80 years, were included in the SR. Eight studies were selected for meta-analysis (414 and 216 subjects in the intervention and control groups). Lutein and zeaxanthin plus n-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA) supplementation showed significant improvements in best-corrected visual acuity (BCVA) (SMD: −1.99, 95% CI: −3.33, −0.65) compared to the control group. Multifocal electroretinogram results (mfERG) were significantly improved overall (SMD: 4.59, 95% CI: 1.75, 7.43) after L plus Z supplementation. Conclusions: Combinations of lutein and zeaxanthin with n-3 LC-PUFA might be beneficial in preventing AMD progression and deterioration of visual function. Our results encourage initiating further studies with combinations of n-3 LC-PUFA, lutein, and zeaxanthin especially in early AMD patients.

Head-mounted digital metamorphopsia suppression as a countermeasure for macular-related visual distortions for prolonged spaceflight missions and terrestrial health

During long-duration spaceflight, astronauts are exposed to various risks including spaceflight-associated neuro-ocular syndrome, which serves as a risk to astronaut vision and a potential physiological barrier to future spaceflight. When considering exploration missions that may expose astronauts to longer periods of microgravity, radiation exposure, and natural aging processes during spaceflight, more severe changes to functional vision may occur. The macula plays a critical role in central vision and disruptions to this key area in the eye may compromise functional vision and mission performance. In this article, we describe the development of a countermeasure technique to digitally suppress monocular central visual distortion with head-mounted display technology. We report early validation studies with this noninvasive countermeasure in individuals with simulated metamorphopsia. When worn by these individuals, this emerging wearable countermeasure technology has demonstrated a suppression of monocular visual distortion. We describe the considerations and further directions of this head-mounted technology for both astronauts and aging individuals on Earth.

Importance of Bmal1 in Alzheimer's disease and associated aging-related diseases: Mechanisms and interventions

With the aging world population, the prevalence of aging-related disorders is on the rise. Diseases such as Alzheimer's, type 2 diabetes mellitus (T2DM), Parkinson's, atherosclerosis, hypertension, and osteoarthritis are age-related, and most of these diseases are comorbidities or risk factors for AD; however, our understandings of molecular events that regulate the occurrence of these diseases are still not fully understood. Brain and muscle Arnt-like protein-1 (Bmal1) is an irreplaceable clock gene that governs multiple important physiological processes. Continuous research of Bmal1 in AD and associated aging-related diseases is ongoing, and this review picks relevant studies on a detailed account of its role and mechanisms in these diseases. Oxidative stress and inflammation turned out to be common mechanisms by which Bmal1 deficiency promotes AD and associated aging-related diseases, and other Bmal1-dependent mechanisms remain to be identified. Promising therapeutic strategies involved in the regulation of Bmal1 are provided, including melatonin, natural compounds, metformin, d-Ser2-oxyntomodulin, and other interventions, such as exercise, time-restricted feeding, and adiponectin. The establishment of the signaling pathway network for Bmal1 in aging-related diseases will lead to advances in the comprehension of the molecular and cellular mechanisms, shedding light on novel treatments for aging-related diseases and promoting aging-associated brain health.

Advances in Optical Coherence Tomography Imaging Technology and Techniques for Choroidal and Retinal Disorders

Optical coherence tomography (OCT) imaging has played a pivotal role in the field of retina. This light-based, non-invasive imaging modality provides high-quality, cross-sectional analysis of the retina and has revolutionized the diagnosis and management of retinal and choroidal diseases. Since its introduction in the early 1990s, OCT technology has continued to advance to provide quicker acquisition times and higher resolution. In this manuscript, we discuss some of the most recent advances in OCT technology and techniques for choroidal and retinal diseases. The emerging innovations discussed include wide-field OCT, adaptive optics OCT, polarization sensitive OCT, full-field OCT, hand-held OCT, intraoperative OCT, at-home OCT, and more. The applications of these rising OCT systems and techniques will allow for a closer monitoring of chorioretinal diseases and treatment response, more robust analysis in basic science research, and further insights into surgical management. In addition, these innovations to optimize visualization of the choroid and retina offer a promising future for advancing our understanding of the pathophysiology of chorioretinal diseases.

Automated segmentation and feature discovery of age-related macular degeneration and Stargardt disease via self-attended neural networks

Age-related macular degeneration (AMD) and Stargardt disease are the leading causes of blindness for the elderly and young adults respectively. Geographic atrophy (GA) of AMD and Stargardt atrophy are their end-stage outcomes. Efficient methods for segmentation and quantification of these atrophic lesions are critical for clinical research. In this study, we developed a deep convolutional neural network (CNN) with a trainable self-attended mechanism for accurate GA and Stargardt atrophy segmentation. Compared with traditional post-hoc attention mechanisms which can only visualize CNN features, our self-attended mechanism is embedded in a fully convolutional network and directly involved in training the CNN to actively attend key features for enhanced algorithm performance. We applied the self-attended CNN on the segmentation of AMD and Stargardt atrophic lesions on fundus autofluorescence (FAF) images. Compared with a preexisting regular fully convolutional network (the U-Net), our self-attended CNN achieved 10.6% higher Dice coefficient and 17% higher IoU (intersection over union) for AMD GA segmentation, and a 22% higher Dice coefficient and a 32% higher IoU for Stargardt atrophy segmentation. With longitudinal image data having over a longer time, the developed self-attended mechanism can also be applied on the visual discovery of early AMD and Stargardt features.

Terrestrial health applications of visual assessment technology and machine learning in spaceflight associated neuro-ocular syndrome

The neuro-ocular effects of long-duration spaceflight have been termed Spaceflight Associated Neuro-Ocular Syndrome (SANS) and are a potential challenge for future, human space exploration. The underlying pathogenesis of SANS remains ill-defined, but several emerging translational applications of terrestrial head-mounted, visual assessment technology and machine learning frameworks are being studied for potential use in SANS. To develop such technology requires close consideration of the spaceflight environment which is limited in medical resources and imaging modalities. This austere environment necessitates the utilization of low mass, low footprint technology to build a visual assessment system that is comprehensive, accessible, and efficient. In this paper, we discuss the unique considerations for developing this technology for SANS and translational applications on Earth. Several key limitations observed in the austere spaceflight environment share similarities to barriers to care for underserved areas on Earth. We discuss common terrestrial ophthalmic diseases and how machine learning and visual assessment technology for SANS can help increase screening for early intervention. The foundational developments with this novel system may help protect the visual health of both astronauts and individuals on Earth.

Fast and Efficient Method for Optical Coherence Tomography Images Classification Using Deep Learning Approach

The use of optical coherence tomography (OCT) in medical diagnostics is now common. The growing amount of data leads us to propose an automated support system for medical staff. The key part of the system is a classification algorithm developed with modern machine learning techniques. The main contribution is to present a new approach for the classification of eye diseases using the convolutional neural network model. The research concerns the classification of patients on the basis of OCT B-scans into one of four categories: Diabetic Macular Edema (DME), Choroidal Neovascularization (CNV), Drusen, and Normal. Those categories are available in a publicly available dataset of above 84,000 images utilized for the research. After several tested architectures, our 5-layer neural network gives us a promising result. We compared them to the other available solutions which proves the high quality of our algorithm. Equally important for the application of the algorithm is the computational time, which is reduced by the limited size of the model. In addition, the article presents a detailed method of image data augmentation and its impact on the classification results. The results of the experiments were also presented for several derived models of convolutional network architectures that were tested during the research. Improving processes in medical treatment is important. The algorithm cannot replace a doctor but, for example, can be a valuable tool for speeding up the process of diagnosis during screening tests.

Associations of Tumor Necrosis Factor-Alpha Gene Polymorphisms (TNF)-α TNF-863A/C (rs1800630), TNF-308A/G (rs1800629), TNF-238A/G (rs361525), and TNF-Alpha Serum Concentration with Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is a neurodegenerative disease leading to irreversible central vision loss among the elderly in developed countries. While the disease accounts for 9% of all cases of vision loss, the prevalence of AMD is likely to increase due to the exponential aging of the population. Due to this reason, our study aimed to determine the associations of tumor necrosis factor-alpha (TNF-α) gene single-nucleotide polymorphisms (SNPs) TNF-863A/C (rs1800630), TNF-308A/G (rs1800629), TNF-238A/G (rs361525), and TNF-α serum concentration with age-related macular degeneration. Analysis of TNF-α rs1800630, rs1800629, and rs361525 polymorphisms showed that the TNF-α rs1800630 A allele was statistically significantly more frequent in the exudative AMD group compared to the control group (p = 0.029). Additionally, the TNF-α rs1800630 A allele was more frequent in females with exudative AMD than in the control group of healthy females (p = 0.027). The TNF-α rs1800630 A allele was more frequent in females with exudative AMD than in females with early AMD (p = 0.014). TNF-α rs1800630, rs1800629, and rs361525 haplotype A-A-G were associated with decreased odds of exudative AMD (p < 0.0001), and haplotype A-G-G was associated with 24-fold increased exudative AMD occurrence (p < 0.0001). TNF-α protein levels were lower in subjects with exudative AMD compared to the control group (p < 0.001). The study showed significant associations between inflammatory cytokine TNF-α single-nucleotide polymorphisms and serum level with AMD pathogenesis. Analysis of TNF-α genotypes and serum concentration may be helpful for the AMD diagnosis.

Changes in best-corrected visual acuity in patients with dry age-related macular degeneration after stem cell transplantation: systematic review and meta-analysis

Background

Stem cell transplantation may improve visual acuity in patients with dry age-related macular degeneration. Herein, we aimed to summarise the evidence on the risks and benefits of stem cell transplantation for improving visual acuity, including the risk of adverse events.

Methods

Data were obtained from the PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials databases, and each database was interrogated from the date of inception until 19 March 2022. The rates of visual acuity outcomes and adverse events associated with stem cell transplantation were examined. All statistical analyses were conducted using Review Manager 5.4. The study was registered with PROSPERO (CRD 42022322902).

Results

The analysis examined 10 studies (102 patients), including one and three, randomised and non-randomised clinical trials, and one and five, multicentre prospective and prospective clinical trials, respectively. Meta-analysis showed changes in best-corrected visual acuity in the study eyes after stem cell transplantation (6 months: risk ratio [RR] = 17.00, 95% confidence interval [CI] 6.08–47.56, P < 0.00001; 12 months: RR = 11.00, 95% CI 2.36–51.36, P = 0.002). Subgroup analysis showed that different stem cell types achieved better best-corrected visual acuity at post-operative 6 months, compared to that observed at baseline. Four cases of related ocular adverse events and no related systemic adverse events were reported.

Conclusion

This meta-analysis suggests that stem cell transplantation may improve best-corrected visual acuity in dry age-related macular degeneration, based on small sample sizes and fewer randomised controlled trials.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02931-y.

nAMD: optimization of patient care and patient-oriented information with the help of an internet-based survey

PURPOSE

This survey was conducted to identify factors that influence how patients with neovascular age-related macular degeneration (nAMD) deal with their disease and information that are considered useful from a patient's point of view.

METHODS

A total of 5035 patients with nAMD living in Germany were interviewed via internet-based cross-sectional survey, where the following information was collected: personal data, disease awareness, and patients' needs. In addition, a Quality of Life questionnaire (SF-12v2) could be completed.

RESULTS

Out of the 5035 participants, more males than females participated (55% vs 45%), and most participants were in the age groups 76 to 85 years (37%) and 66 to 75 years (35%). Seventy-three percent of patients rated their understanding of the disease as at least sufficient, and more than two-thirds of the patients (68%) were aware that their disease needs to be controlled on a regular basis and treated on an "as needed" basis. Regarding potential risk factors for AMD, most participants were aware of age (89%), but only 39% of hereditary load and 33% of smoking as evidence-based risk factors, indicating a need for further information. The doctor remains the major source of information (93%), with internet (29%), brochures (14%), opticians (13%), or patient support groups (4%) with only limited contribution. Distance to the treatment center was identified as one of the factors, which had the greatest influence on patients' compliance. A "treat as needed" regime turned out to be the preferred control and treatment schedule in contrast to a "fixed appointment" every 4 weeks.

CONCLUSION

This internet-based survey appears to be representative for nAMD patients. To increase patients' compliance, proximity to the treatment center and a "treat as needed" regime turned out to be important factors as well as patients' awareness of their disease. In this regard, the reported desire for more information indicates that patients' knowledge still needs to be improved. Our results will help to further optimize patient care and patient-oriented information.

The Efficacy and Safety of Brolucizumab for the Treatment of nAMD: A Systematic Review and Meta-Analysis

Introduction: As demonstrated in pivotal clinical trials, brolucizumab can be used to treat neovascular age-related macular degeneration (nAMD) because it antagonizes vascular endothelial growth factor (VEGF) in the vitreous. However, brolucizumab may cause retinal vasculitis obliterans in the presence of inflammation in the eyes. In the present study, a meta-analysis of randomized controlled trials (RCTs) was conducted to evaluate the efficacy and safety of brolucizumab.

Methods:ClinicTrail.gov., Embase, Cochrane Library, and PubMed were retrieved from inception until 31 December 2021 for RCTs assessing the efficacy and safety of brolucizumab. Changes in best corrected visual acuity (BCVA) and central sub-field thickness (CSFT) and incidence of adverse events, serious adverse events, and serious ocular adverse events were extracted from eligible RCTs. A meta-analysis was performed using RevMan 5.4.1.

Results: A total of six RCTs with 3,574 participants were finally involved in this meta-analysis. The changes of best corrected visual acuity (BCVA) showed no statistically significant difference between the brolucizumab-treated group and aflibercept-treated group. Brolucizumab induced higher central sub-field thickness (CSFT) reduction than the control agent (aflibercept). The incidence of adverse events was similar between the brolucizumab group and control group (OR 0.63, 95% CI 0.37 to 1.08, p = 0.09), and brolucizumab caused fewer serious adverse events (OR 0.78, 95% CI 0.63 to 0.95, p = 0.01). However, brolucizumab could lead to more serious ocular adverse events than Lucentis and aflibercept (OR 2.15, 95% CI 1.11 to 4.16, p = 0.02).

Conclusion: Brolucizumab was non-inferior to other anti-VEGF agents in improving BCVA and decreasing CSFT. But it caused more serious ocular adverse events which is worthy of special attention by ophthalmologists.

The Relationship between Statin and Risk of Age-Related Macular Degeneration: A Systematic Review and Meta-Analysis

Introduction and Aim. Age-related macular degeneration (AMD) is one of the leading causes of blindness and visual defect, particularly in elderly people across the world. This meta-analysis aimed at investigating the relationship between statin and the risk of AMD. Methods. Web of Science, PubMed, and Scopus databases were searched for articles that addressed the relationship between statin consumption and risk of AMD. The pooled odds ratio (OR) and 95% confidence interval (CI) were calculated using a random-effects model. Subgroup analyses and sensitivity analyses were also conducted. Cochran’s Q test and the I2 statistic were used to evaluate the heterogeneity. To assess potential publication bias, Begg’s test was used. Results. In total, 22 studies were reviewed in the meta-analysis that included 2063195 participants and 313702 (15.20%) AMD patients compared to individuals not receiving statins. The OR of AMD in statin-receiving participants was 0.93 (95% CI; 0.83–1.05, $P=0.225$ ). The OR of AMD in those that received statins was 0.92 (95% CI; 0.75–1.13, $P=0.440$ ) in case-control studies, 0.95 (95% CI; 0.82–1.09, $P=0.458$ ) in cohort studies, 0.951 (95% CI; 0.59–1.53, $P=0.831$ ) in cross-sectional studies, 0.94 (95% CI; 0.80–1.10, $P=0.468$ ) in North America, 0.81 (95% CI; 0.54–1.21, $P=0.308$ ) in Europe, 1.05 (95% CI; 0.94–1.18, $P=0.362$ ) in Asia, and 0.52 (95% CI; 0.26–1.04, $P=0.125$ ) in Australia. No publication bias was observed in this study ( $P=0.114$ ). Conclusion. According to the results of this study, taking statins does not increase or decrease the risk of AMD development. Therefore, this drug group cannot be considered a protective or risk factor for the occurrence of AMD.

Biomarkers as Predictive Factors of Anti-VEGF Response

Age-related macular degeneration is the main cause of irreversible vision in developed countries, and intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections are the current gold standard treatment today. Although anti-VEGF treatment results in important improvements in the course of this disease, there is a considerable number of patients not responding to the standardized protocols. The knowledge of how a patient will respond or how frequently retreatment might be required would be vital in planning treatment schedules, saving both resource utilization and financial costs, but today, there is not an ideal biomarker to use as a predictive response to ranibizumab therapy. Whole blood and blood mononuclear cells are the samples most studied; however, few reports are available on other important biofluid samples for studying this disease, such as aqueous humor. Moreover, the great majority of studies carried out to date were focused on the search for SNPs in genes related to AMD risk factors, but miRNAs, proteomic and metabolomics studies have rarely been conducted in anti-VEGF-treated samples. Here, we propose that genomic, proteomic and/or metabolomic markers could be used not alone but in combination with other methods, such as specific clinic characteristics, to identify patients with a poor response to anti-VEGF treatment to establish patient-specific treatment plans.

Können digitale Instrumente wie die Makula-App die AMD-Therapie unterstützen?

Hintergrund Eine lang andauernde und kontinuierliche Anti-VEGF-Therapie ist bei der neovaskulären altersabhängigen Makuladegeneration (nAMD) der therapeutische „Goldstandard“, um individuell das bestmögliche Sehvermögen zu erhalten. Das Management der Erkrankung bedeutet für Betroffene und Angehörige eine große Herausforderung. Dabei bleiben Real-Life-Ergebnisse von Patienten unter der Anti-VEGF-Therapie (IVOM-Therapie) oft hinter denen aus randomisierten klinischen Studien zurück. Das Ziel der vorliegenden Studie war es, zu untersuchen, ob digitale Instrumente, wie die vom AMD-Netz entwickelte Makula-App 1.0, dies unterstützen können.

Patienten und Methoden Die Ergebnisse einer in die Makula-App 1.0 integrierten Nutzerbefragung (n = 110) sowie einer zusätzlichen direkten Befragung zum Thema „Digitales Terminmanagement in der IVOM-Therapie“ von Augenärzten (n = 54) und Patienten (n = 60) werden bez. Nutzung und Akzeptanz der Makula-App analysiert.

Ergebnisse Die Befragungen ergaben, dass 79% der Nutzer den Informationen der Makula-App 1.0 vertrauen, 71% finden die App sowie das Terminmanagement hilfreich für den Alltag und 80% der Nutzer würden die App weiterempfehlen. 52% der Augenärzte und 65% der Patienten sehen einen deutlichen Nutzen zukünftiger digitaler Tools für die Patientenadhärenz. Eine digitale Terminmanagementfunktion bewerten auch 82% der Ärzte als wichtig.

Schlussfolgerungen Dem Einsatz der Makula-App 1.0 besonders beim Terminmanagement, aber auch als Informationstool, standen die Nutzer mehrheitlich positiv gegenüber, ebenso wie möglichen Weiterentwicklungen. Auch Augenärzte sehen in digitalen Tools wie der Makula-App 1.0 ein wichtiges Instrument zur Verbesserung des Terminmanagements und der Patientenadhärenz. Diese positiven Einschätzungen unterstützen die Sinnhaftigkeit der Entwicklung einer interaktiven Plattform Makula-App 2.0, die einen direkten Austausch zwischen Patienten und Augenarzt ermöglichen kann.

Exudative versus Nonexudative Age-Related Macular Degeneration: Physiopathology and Treatment Options

Age-related macular degeneration (AMD) is an eye disease typically associated with the aging and can be classified into two types—namely, the exudative and the nonexudative AMD. Currently available treatments for exudative AMD use intravitreal injections, which are associated with high risk of infection that can lead to endophthalmitis, while no successful treatments yet exist for the nonexudative form of AMD. In addition to the pharmacologic therapies administered by intravitreal injection already approved by the Food and Drug Administration (FDA) in exudative AMD, there are some laser treatments approved that can be used in combination with the pharmacological therapies. In this review, we discuss the latest developments of treatment options for AMD. Relevant literature available from 1993 was used, which included original articles and reviews available in PubMed database and also information collected from Clinical Trials Gov website using “age-related macular degeneration” and “antiangiogenic therapies” as keywords. The clinical trials search was limited to ongoing trials from 2015 to date.

Automatic Detection of Age-Related Macular Degeneration Based on Deep Learning and Local Outlier Factor Algorithm

Age-related macular degeneration (AMD) is a retinal disorder affecting the elderly, and society’s aging population means that the disease is becoming increasingly prevalent. The vision in patients with early AMD is usually unaffected or nearly normal but central vision may be weakened or even lost if timely treatment is not performed. Therefore, early diagnosis is particularly important to prevent the further exacerbation of AMD. This paper proposed a novel automatic detection method of AMD from optical coherence tomography (OCT) images based on deep learning and a local outlier factor (LOF) algorithm. A ResNet-50 model with L2-constrained softmax loss was retrained to extract features from OCT images and the LOF algorithm was used as the classifier. The proposed method was trained on the UCSD dataset and tested on both the UCSD dataset and Duke dataset, with an accuracy of 99.87% and 97.56%, respectively. Even though the model was only trained on the UCSD dataset, it obtained good detection accuracy when tested on another dataset. Comparison with other methods also indicates the efficiency of the proposed method in detecting AMD.

Patient Preferences in the Management of Wet Age-Related Macular Degeneration: A Conjoint Analysis

INTRODUCTION

To identify patient preference drivers related to the management of wet age-related macular degeneration (wet AMD).

METHODS

In this cross-sectional study, a self-explicated 'conjoint analysis' survey was administered online to eligible patients with wet AMD (receiving anti-vascular endothelial growth factor [VEGF] treatment for at least 12 months) from the USA, Canada, UK, France, Spain, Germany, Italy, Japan, Taiwan, and Australia. The survey consisted of six domains with 21 attributes, which were selected on the basis of a literature review, social media listening, and tele-interviews/discussions with patients, clinical experts, and patient groups. Utility and relative importance scores were generated for each attribute and utility difference significance testing was performed using 'unequal variances t tests'. The Patient Activation Measure (PAM-13) questionnaire was administered to assess patients' knowledge, skill, and confidence in self-management.

RESULTS

A total of 466 patients (mean age, 68 years; women, 54%; binocular wet AMD, 28%) with an average anti-VEGF treatment duration of 3.9 years completed the survey. The most important preference domains were 'treatment effects on vision' (non-significant) and 'vision-related symptom burdens' (p < 0.001), followed by 'treatment risk' (p < 0.05), 'impact on daily activities' (p < 0.05), 'burden of clinic/hospital visits' (p < 0.001), and 'impact on psychological well-being'. The five most important attributes in order of importance were clarity of vision, treatment effect on symptoms, quality of vision, time to treatment effect, and time to re-administration. The two most important attributes globally were also in the top three attributes across countries. The majority of participants in the study were level 3 or level 4 of the PAM-13 questionnaire.

CONCLUSIONS

This study identified the most important disease and treatment attributes to patients using patient-centred methods. The data showed the degree of harmonization of preferences across geographies and that participants actively adopt behaviours required for improved treatment outcomes. The identified preference drivers may inform future clinical development.