Age-Related Macular Degeneration: Epidemiology, Pathophysiology, Diagnosis, and Treatment

Gallic Acid-Encapsulated PAMAM Dendrimers as an Antioxidant Delivery System for Controlled Release and Reduced Cytotoxicity against ARPE-19 Cells

Poly(amidoamine) (PAMAM) dendrimers have gained significant attention in various research fields, particularly in medicinal compound delivery. Their versatility lies in their ability to conjugate with functional molecules on their surfaces and encapsulate small molecules, making them suitable for diverse applications. Gallic acid is a potent antioxidant compound that has garnered considerable interest in recent years. Our research aims to investigate if the gallic acid-encapsulated PAMAM dendrimer generations 4 (G4(OH)-Ga) and 5 (G5(OH)-Ga) could enhance radical scavenging, which could potentially slow down the progression of age-related macular degeneration (AMD). Encapsulation of gallic acid in PAMAM dendrimers is a feasible alternative to prevent its degradation and toxicity. In vitro investigation of antioxidant activity was carried out using the DPPH and ABTS radical scavenging assays, as well as the FRAP assay. The IC50 values for DPPH and ABTS assays were determined through nonlinear dose-response curves, correlating the inhibition percentage with the concentration (μg/mL) of the sample and the concentration (μM) of gallic acid within each sample. G4(OH)-Ga and G5(OH)-Ga possess significant antioxidant activities as determined by the DPPH, ABTS, and FRAP assays. Moreover, gallic acid-encapsulated PAMAM dendrimers inhibit H2O2-induced reactive oxygen species (ROS) production in the human retinal pigment epithelium ARPE-19 cells, thereby improving antioxidant characteristics and potentially retarding AMD progression caused by ROS. In an evaluation of cell viability of ARPE-19 cells using the MTT assay, G4(OH)-Ga was found to reduce cytotoxic effects on ARPE-19 cells.

State of the art CRISPR-based strategies for cancer diagnostics and treatment

Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) technology is a groundbreaking and dynamic molecular tool for DNA and RNA "surgery". CRISPR/Cas9 is the most widely applied system in oncology research. It is a major advancement in genome manipulation due to its precision, efficiency, scalability and versatility compared to previous gene editing methods. It has shown great potential not only in the targeting of oncogenes or genes coding for immune checkpoint molecules, and in engineering T cells, but also in targeting epigenomic disturbances, which contribute to cancer development and progression. It has proven useful for detecting genetic mutations, enabling the large-scale screening of genes involved in tumor onset, progression and drug resistance, and in speeding up the development of highly targeted therapies tailored to the genetic and immunological profiles of the patient's tumor. Furthermore, the recently discovered Cas12 and Cas13 systems have expanded Cas9-based editing applications, providing new opportunities in the diagnosis and treatment of cancer. In addition to traditional cis-cleavage, they exhibit trans-cleavage activity, which enables their use as sensitive and specific diagnostic tools. Diagnostic platforms like DETECTR, which employs the Cas12 enzyme, that cuts single-stranded DNA reporters, and SHERLOCK, which uses Cas12, or Cas13, that specifically target and cleave single-stranded RNA, can be exploited to speed up and advance oncological diagnostics. Overall, CRISPR platform has the great potential to improve molecular diagnostics and the functionality and safety of engineered cellular medicines. Here, we will emphasize the potentially transformative impact of CRISPR technology in the field of oncology compared to traditional treatments, diagnostic and prognostic approaches, and highlight the opportunities and challenges raised by using the newly introduced CRISPR-based systems for cancer diagnosis and therapy.

Outcomes of Anti-VEGF Therapy in Eyes with Diabetic Macular Edema, Vein Occlusion-Related Macular Edema, and Neovascular Age-Related Macular Degeneration: A Systematic Review

Background

Anti-vascular endothelial growth factor (anti-VEGF) therapy has revolutionized the management of various ocular conditions, including diabetic macular edema (DME), retinal vein occlusion (RVO)-related macular edema (ME), and neovascular age-related macular degeneration (nAMD). However, there remains a need to systematically assess its effectiveness across these distinct conditions.

Methodology

A systematic review was conducted to identify studies evaluating the efficacy of anti-VEGF therapy in improving ocular outcomes in patients with DME, RVO-related ME, and nAMD. PubMed, Embase, and Cochrane Library databases were searched for relevant articles published up to 2024. Studies meeting the inclusion criteria were critically appraised, and data on the proportion of patients gaining ≥15 Early Treatment Diabetic Retinopathy Study (ETDRS) letters in best-corrected visual acuity (BCVA), mean change in BCVA (ETDRS letters), and reduction in central macular thickness (CMT) (μm) were extracted and synthesized.

Results

The systematic review identified 18 studies comprising randomized controlled trials, prospective studies, retrospective analyses, and observational studies. Anti-VEGF therapy demonstrated efficacy across all three conditions, with varying proportions of patients experiencing improvements in BCVA and reductions in CMT. Notably, the proportion of patients gaining ≥15 ETDRS letters ranged from 18.1% to 44.8% in DME, while mean changes in BCVA ranged from +4.2 letters to +21.4 letters in RVO-related ME and nAMD. Reductions in CMT ranged from 183.1 μm to 294 μm in DME and RVO-related ME.

Conclusion

Anti-VEGF therapy represents a cornerstone in the management of DME, RVO-related ME, and nAMD, with significant improvements observed in BCVA and reductions in CMT across diverse patient populations. While our findings support the effectiveness of anti-VEGF therapy in improving ocular outcomes, further research is warranted to compare its efficacy with alternative treatment modalities and to elucidate its long-term safety profile.

Intravitreal Faricimab for Previously Treated Neovascular Age-Related Macular Degeneration

Purpose

To report our real-world experience using intravitreal faricimab, a novel anti-vascular endothelial growth factor (anti-VEGF) therapy, in eyes with neovascular age-related macular degeneration (nAMD) previously treated with other anti-VEGF therapy.

Patients and Methods

A retrospective, single-center study of previously treated nAMD eyes treated with faricimab.

Results

In 88 eyes (73 patients), mean baseline best-corrected visual acuity (BCVA) was 20/63 (range 20/20 to CF) with mean anti-VEGF injection interval of 6.1+2.0 weeks. Mean baseline central subfield thickness (CST) was 291+73 µm. During mean follow-up of 30.1+13.5 (range 7.0 to 50.3) weeks on faricimab, the eyes received an average of 5.1+2.4 injections (range 1 to 11). Mean BCVA remained at 20/63 (p=0.11), but injection interval increased to 7.4+2.6 weeks (p<0.001), and CST decreased to 262+63 µm (p<0.001). Multiple linear regression analysis revealed that higher number of different anti-VEGF drugs used at baseline was associated with a lower decrease in CST on faricimab (p=0.04) while total number of anti-VEGF injections at baseline (p=0.56) and time on faricimab (p=0.68) were not associated. Faricimab was discontinued in 23 eyes (26.1%), including 8 eyes for poor response, 2 eyes for persistent new floaters and 4 eyes for new vision decrease which reversed after stopping faricimab.

Conclusion

In previously treated nAMD eyes, intravitreal faricimab was associated with increased mean treatment interval and decreased CST but no improvement in mean BCVA. The benefit of faricimab on CST reduction may be diminished in eyes previously treated with multiple different types of anti-VEGF therapy.

Global Insights from Patients, Providers, and Staff on Challenges and Solutions in Managing Neovascular Age-Related Macular Degeneration

INTRODUCTION

Neovascular age-related macular degeneration is a global public-health concern, associated with a considerable burden to individuals, healthcare systems, and society. The objective of this study was to understand different perspectives on the challenges associated with the clinical management of neovascular age-related macular degeneration, which could elucidate measures to comprehensively improve clinical care and outcomes.

METHODS

A survey was carried out of patients with neovascular age-related macular degeneration, their providers, and clinic staff in 77 clinics across 24 countries on six continents, from a diverse range of healthcare systems, settings, and reimbursement models. Surveys comprised a series of single/multiple-response questions completed anonymously. Data gathered included patient personal characteristics, appointment attendance challenges, treatment experiences, and opportunities to improve support. Provider and clinic staff surveys asked similar questions about their perspectives; clinic characteristics were also captured.

RESULTS

There were 6425 responses; 4558 patients with neovascular age-related macular degeneration, 659 providers, and 1208 clinic staff. Challenges identified included concern about patient burden to family/friends, high frequency of treatment, difficulties in traveling to appointments, long waiting times, and insufficient comprehension of neovascular age-related macular degeneration. Participants identified logistical (improved financial assistance with treatment and out-of-pocket costs, and appointment reminders), operational (addressing clinic set up to reduce waiting times and improving the amount of time providers spend with patients), and educational (improving quality and provision of patient information and expectation-setting) opportunities to improve care.

CONCLUSIONS

The wealth of data generated by this global survey highlights the breadth of challenges associated with clinical management of patients with neovascular age-related macular degeneration. Addressing the opportunities raised could improve patient adherence to treatment and potentially outcomes, reduce appointment burden, and increase clinic capacity.

Bilateral occlusive retinal vasculitis secondary to intravitreal faricimab injection: a case report and review of literature

BACKGROUND

This article describes a rare occurrence of bilateral retinal occlusive vasculitis secondary to intravitreal faricimab injection.

CASE PRESENTATION

A 72-year-old female with age-related macular degeneration presented with bilateral retinal occlusive vasculitis following intravitreal faricimab injections. The patient was treated with 3 days of intravenous methylprednisolone followed by oral prednisolone taper and topical steroid therapy. Resolution of retinal occlusive vasculitis was observed 2 months post treatment.

CONCLUSIONS

Retinal occlusive vasculitis is a rare complication of intravitreal anti-vascular endothelial growth factor (anti-VEGF), particularly with faricimab injections. We also present a review of literature regarding retinal occlusive vasculitis following intravitreal anti-VEGF injections and propose further information regarding its pathophysiology.

Choroidal Control Technology: New Horizons in Maculopathy and Presbyopia

OBJECTIVE

To evaluate changes in choroidal thickness in presbyopes, when reading with regular glasses versus choroidal control glasses, in patients with or without Age-Related Macular Degeneration (AMD).

METHODS

This was a pilot study on short-term axial length (AL) in 33 eyes of 24 presbyopic patients aged 60 to 80 years, assigned to two age-matched groups, with or without AMD. About them, changes in choroidal thickness were evaluated with ocular biometry through indirect measurements of axial length at baseline, after 20' of reading with conventional lenses, and after another 20' of reading with peripheral hyperopic defocus glasses. The differences in axial length between the three different times were analyzed.

RESULTS

In presbyopes without AMD there was a significant axial length shortening of -13.44 microns in the first conventional reading period, which was reversed by 90% with hyperopic defocus lenses, recovering + 12.11 microns by axial lengthening (choroidal thinning, p = 0.03). In patients with AMD, axial shortening was significantly greater than controls, -23.86 microns with conventional lenses (p < 0.001) and they, also increased their axial length with defocus, although this response was smaller in proportion (+ 15.52 microns).

CONCLUSION

Reading with positive lenses produces myopic defocus and choroidal thickening in presbyopes with and without AMD but was significantly greater in the latter. Glasses with Choroidal Control Technology reduced thickening during reading.

KEY MESSAGES

What is known • Presbyopia spectacles for near produce myopic defocus and choroidal thickening. What is new • There are differences in choroidal thickening during reading between normal subjects and those with age related macular degeneration. • Spectacles with Defocus Choroidal Control Technology reduce choroidal thickening during reading in presbyopes.

Usability of the SB11 Pre-filled Syringe (PFS) in Patients with Retinal Diseases

INTRODUCTION

SB11 (Byooviz™; Samsung Bioepis Co., Ltd.) is a ranibizumab (Lucentis®; Genentech, Inc.) biosimilar targeting vascular endothelial growth factor A for the treatment of retinal diseases. The pre-filled syringe (PFS) presentation of SB11 offers an alternative administration method to the vial, with the potential for enhanced safety and efficient syringe preparation. The objective of this study was to assess the ability of healthcare professionals (HCPs) to follow the instructions for use to prepare and administer SB11 PFS intravitreal (IVT) injections to patients with neovascular age-related macular degeneration (nAMD) or macular edema secondary to retinal vein occlusion (RVO).

METHODS

This study was an open-label, single-arm, single-dose clinical study to evaluate the usability of the SB11 PFS in patients with nAMD or macular edema secondary to RVO. Four HCPs prepared and administered 0.5 mg SB11 PFS IVT injections to 34 patients. Product use task completion (12 tasks in total) was assessed by independent observers. Safety was assessed up to 7 days after injection of the investigational product.

RESULTS

A total of 34 patients were enrolled and completed the study. All 12 tasks were successfully completed in 34 (100%) patients without a use-related failure. Most patients (32 patients, 94.1%) experienced no adverse events (AEs), whereas 2 (5.9%) patients experienced three treatment-emergent AEs (TEAEs) which were mild to moderate in severity. There were no severe or serious TEAEs reported during the study.

CONCLUSIONS

This study showed that HCPs were able to successfully prepare and administer the SB11 PFS via IVT injection. No unexpected safety issues were identified. The SB11 PFS is a promising alternative for therapeutic administration of SB11 in patients with retinal disease.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT06176963; EudraCT number 2021-003566-12.

Anti-angiogenic biomolecules in neovascular age-related macular degeneration; therapeutics and drug delivery systems

Blindness in the elderly is often caused by age-related macular degeneration (AMD). The advanced type of AMD known as neovascular AMD (nAMD) has been linked to being the predominant cause of visual impairment in these people. Multiple neovascular structures including choroidal neovascular (CNV) membranes, fluid exudation, hemorrhages, and subretinal fibrosis, are diagnostic of nAMD. These pathological alterations ultimately lead to anatomical and visual loss. It is known that vascular endothelial growth factor (VEGF), a type of proangiogenic factor, mediates the pathological process underlying nAMD. Therefore, various therapies have evolved to directly target the disease. In this review article, an attempt has been made to discuss general explanations about this disease, all common treatment methods based on anti-VEGF drugs, and the use of drug delivery systems in the treatment of AMD. Initially, the pathophysiology, angiogenesis, and different types of AMD were described. Then we described current treatments and future treatment prospects for AMD and outlined the advantages and disadvantages of each. In this context, we first examined the types of therapeutic biomolecules and anti-VEGF drugs that are used in the treatment of AMD. These biomolecules include aptamers, monoclonal antibodies, small interfering RNAs, microRNAs, peptides, fusion proteins, nanobodies, and other therapeutic biomolecules. Finally, we described drug delivery systems based on liposomes, nanomicelles, nanoemulsions, nanoparticles, cyclodextrin, dendrimers, and composite vehicles that are used in AMD therapy.

Urolithin A promotes p62-dependent lysophagy to prevent acute retinal neurodegeneration

BACKGROUND

Age-related macular degeneration (AMD) is the leading cause of blindness in elderly people in the developed world, and the number of people affected is expected to almost double by 2040. The retina presents one of the highest metabolic demands in our bodies that is partially or fully fulfilled by mitochondria in the neuroretina and retinal pigment epithelium (RPE), respectively. Together with its post-mitotic status and constant photooxidative damage from incoming light, the retina requires a tightly-regulated housekeeping system that involves autophagy. The natural polyphenol Urolithin A (UA) has shown neuroprotective benefits in several models of aging and age-associated disorders, mostly attributed to its ability to induce mitophagy and mitochondrial biogenesis. Sodium iodate (SI) administration recapitulates the late stages of AMD, including geographic atrophy and photoreceptor cell death.

METHODS

A combination of in vitro, ex vivo and in vivo models were used to test the neuroprotective potential of UA in the SI model. Functional assays (OCT, ERGs), cellular analysis (flow cytometry, qPCR) and fine confocal microscopy (immunohistochemistry, tandem selective autophagy reporters) helped address this question.

RESULTS

UA alleviated neurodegeneration and preserved visual function in SI-treated mice. Simultaneously, we observed severe proteostasis defects upon SI damage induction, including autophagosome accumulation, that were resolved in animals that received UA. Treatment with UA restored autophagic flux and triggered PINK1/Parkin-dependent mitophagy, as previously reported in the literature. Autophagy blockage caused by SI was caused by severe lysosomal membrane permeabilization. While UA did not induce lysosomal biogenesis, it did restore upcycling of permeabilized lysosomes through lysophagy. Knockdown of the lysophagy adaptor SQSTM1/p62 abrogated viability rescue by UA in SI-treated cells, exacerbated lysosomal defects and inhibited lysophagy.

CONCLUSIONS

Collectively, these data highlight a novel putative application of UA in the treatment of AMD whereby it bypasses lysosomal defects by promoting p62-dependent lysophagy to sustain proteostasis.

Comparative Study on Anti-VEGF in Wet Age-Related Macular Degeneration in the Setting Based on Lean Methodology from the Bari Intravitreal Injection Registry (BIVIR)

INTRODUCTION

Optimizing treatment protocols for wet age-related macular degeneration (wAMD) is an ongoing challenge, as it involves a delicate balance between achieving therapeutic efficacy and minimizing invasive procedures' frequency. This study aimed to apply the Lean methodology and evaluate the effectiveness of this new setting on intravitreal therapy for wAMD, employing different anti-vascular endothelial growth factors (VEGF) drugs (bevacizumab, brolucizumab, aflibercept, ranibizumab), drawing data from the Bari Intravitreal Injections Registry (BIVIR).

METHODS

This was a retrospective, monocentric, nonrandomized, comparative study. Lean methodology was employed to design the new setting and the BIVIR collected information from electronic medical records. Clinical data of four groups, stratified based on the first-line anti-VEGF agents used, were compared. Best-corrected visual acuity (BCVA) and central retinal thickness (CRT) changes were compared between the four groups at 3 and 12 months.

RESULTS

Out of 4990 eyes and 41,323 intravitreal injections (IVs) recorded in BIVIR, 1421 eyes of 1182 patients were included. The mean number of IVs in first year was 6.1 ± 2.5, with no significant differences among the four subgroups. The mean change in BCVA was + 6.2 letters [95% confidence interval (CI) 5.6-6.8] after two IVs, and + 5.9 (95% CI 5.1-6.8) letters after three IVs; at three months, brolucizumab was associated with a greater mean increase in BCVA than bevacizumab (p = 0.050); aflibercept (p = 0.044) and ranibizumab p = 0.047). At the 1-year follow-up, the mean change was + 6.3 letters (95% CI 5.4-7.2), brolucizumab and ranibizumab were associated with a superior improvement in BCVA compared to aflibercept (p = 0.033). Regarding the CRT, a significant reduction was observed in the subgroup treated with brolucizumab at the 3-month follow-up, compared to bevacizumab (p = 0.003), aflibercept (p = 0.015), and ranibizumab (p < 0.001); Aflibercept exhibited a superior effect than ranibizumab (p = 0.001). At 1-year follow-up, aflibercept resulted in a more significant reduction of macular thickness compared to ranibizumab (p = 0.016) while no significant differences were observed among the other drugs.

CONCLUSIONS

Our practical experience showed the effectiveness of the new setting in the treatment of wAMD. This comparative study at 1 year suggested a predominant brolucizumab efficacy on functional outcomes. In addition, brolucizumab and aflibercept appeared to have similar efficacy in fluid control.

Mitochondrial damage and clearance in retinal pigment epithelial cells

Age-related macular degeneration (AMD) is a devastating eye disease that causes permanent vision loss in the central part of the retina, known as the macula. Patients with such severe visual loss face a reduced quality of life and are at a 1.5 times greater risk of death compared to the general population. Currently, there is no cure for or effective treatment for dry AMD. There are several mechanisms thought to underlie the disease, for example, ageing-associated chronic oxidative stress, mitochondrial damage, harmful protein aggregation and inflammation. As a way of gaining a better understanding of the molecular mechanisms behind AMD and thus developing new therapies, we have created a peroxisome proliferator-activated receptor gamma coactivator 1-alpha and nuclear factor erythroid 2-related factor 2 (PGC1α/NFE2L2) double-knockout (dKO) mouse model that mimics many of the clinical features of dry AMD, including elevated levels of oxidative stress markers, damaged mitochondria, accumulating lysosomal lipofuscin and extracellular drusen-like structures in retinal pigment epithelial cells (RPE). In addition, a human RPE cell-based model was established to examine the impact of non-functional intracellular clearance systems on inflammasome activation. In this study, we found that there was a disturbance in the autolysosomal machinery responsible for clearing mitochondria in the RPE cells of one-year-old PGC1α/NFE2L2-deficient mice. The confocal immunohistochemical analysis revealed an increase in autophagosome marker microtubule-associated proteins 1A/1B light chain 3B (LC3B) as well as multiple mitophagy markers such as PTE-induced putative kinase 1 (PINK1) and E3 ubiquitin ligase (PARKIN), along with signs of damaged mitochondria. However, no increase in autolysosome formation was detected, nor was there a colocalization of the lysosomal marker LAMP2 or the mitochondrial marker, ATP synthase β. There was an upregulation of late autolysosomal fusion Ras-related protein (Rab7) in the perinuclear space of RPE cells, together with autofluorescent aggregates. Additionally, we observed an increase in the numbers of Toll-like receptors 3 and 9, while those of NOD-like receptor 3 were decreased in PGC1α/NFE2L2 dKO retinal specimens compared to wild-type animals. There was a trend towards increased complement component C5a and increased involvement of the serine protease enzyme, thrombin, in enhancing the terminal pathway producing C5a, independent of C3. The levels of primary acute phase C-reactive protein and receptor for advanced glycation end products were also increased in the PGC1α/NFE2L2 dKO retina. Furthermore, selective proteasome inhibition with epoxomicin promoted both nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and mitochondrial-mediated oxidative stress, leading to the release of mitochondrial DNA to the cytosol, resulting in potassium efflux-dependent activation of the absent in melanoma 2 (AIM2) inflammasome and the subsequent secretion of interleukin-1β in ARPE-19 cells. In conclusion, the data suggest that there is at least a relative decrease in mitophagy, increases in the amounts of C5 and thrombin and decreased C3 levels in this dry AMD-like model. Moreover, selective proteasome inhibition evoked mitochondrial damage and AIM2 inflammasome activation in ARPE-19 cells.

Role of Oxysterols in Ocular Degeneration Mechanisms and Involvement of P2X7 Receptor

Ocular degeneration, including cataracts, glaucoma, macular degeneration, and diabetic retinopathy, is a major public health challenge, as it affects the quality of life of millions of people worldwide and, in its advanced stages, leads to blindness. Ocular degeneration, although it can affect different parts of the eye, shares common characteristics such as oxysterols and the P2X7 receptor. Indeed, oxysterols, which are cholesterol derivatives, are associated with ocular degeneration pathogenesis and trigger inflammation and cell death pathways. Activation of the P2X7 receptor is also linked to ocular degeneration and triggers the same pathways. In age-related macular degeneration, these two key players have been associated, but further studies are needed to extrapolate this interrelationship to other ocular degenerations.