Senolytic and senomorphic agent procyanidin C1 alleviates structural and functional decline in the aged retina.

Increased cellular senescence burden contributes in part to age-related organ dysfunction and pathologies. In our study, using mouse models of natural aging, we observed structural and functional decline in the aged retina, which was accompanied by the accumulation of senescent cells and senescence-associated secretory phenotype factors. We further validated the senolytic and senomorphic properties of procyanidin C1 (PCC1) both in vitro and in vivo, the long-term treatment of which ameliorated age-related retinal impairment. Through high-throughput single-cell RNA sequencing (scRNA-seq), we comprehensively characterized the retinal landscape after PCC1 administration and deciphered the molecular basis underlying the senescence burden increment and elimination. By exploring the scRNA-seq database of age-related retinal disorders, we revealed the role of cellular senescence and the therapeutic potential of PCC1 in these pathologies. Overall, these results indicate the therapeutic effects of PCC1 on the aged retina and its potential use for treating age-related retinal disorders.

Options for Topical Treatment of Oxidative Eye Diseases with a Special Focus on Retinopathies.

Antioxidants, usually administered orally through the systemic route, are known to counteract the harmful effects of oxidative stress on retinal cells. The formulation of these antioxidants as eye drops might offer a new option in the treatment of oxidative retinopathies. In this review, we will focus on the use of some of the most potent antioxidants in treating retinal neuropathies. Melatonin, known for its neuroprotective qualities, may mitigate oxidative damage in the retina. N-acetyl-cysteine (NAC), a precursor to glutathione, enhances the endogenous antioxidant defense system, potentially reducing retinal oxidative stress. Idebenone, a synthetic analogue of coenzyme Q10, and edaravone, a free radical scavenger, contribute to cellular protection against oxidative injury. Epigallocatechin-3-gallate (EGCG), a polyphenol found in green tea, possesses anti-inflammatory and antioxidant effects that could be beneficial in cases of retinopathy. Formulating these antioxidants as eye drops presents a localized and targeted delivery method, ensuring effective concentrations reach the retina. This approach might minimize systemic side effects and enhance therapeutic efficacy. In this paper, we also introduce a relatively new strategy: the alkylation of two antioxidants, namely, edaravone and EGCG, to improve their insertion into the lipid bilayer of liposomes or even directly into cellular membranes, facilitating their crossing of epithelial barriers and targeting the posterior segment of the eye. The synergistic action of these antioxidants may offer a multifaceted defense against oxidative damage, holding potential for the treatment and management of oxidative retinopathies. Further research and clinical trials will be necessary to validate the safety and efficacy of these formulations, but the prospect of antioxidant-based eye drops represents a promising avenue for future ocular therapies.

Smart Nanocarriers for the Treatment of Retinal Diseases.

Retinal diseases, such as age-related macular degeneration, diabetic retinopathy, and retinoblastoma, stand as the leading causes of irreversible vision impairment and blindness worldwide. Effectively administering drugs for retinal diseases poses a formidable challenge due to the presence of complex ocular barriers and elimination mechanisms. Over time, various approaches have been developed to fabricate drug delivery systems for improving retinal therapy including virus vectors, lipid nanoparticles, and polymers. However, conventional nanocarriers encounter issues related to the controllability, efficiency, and safety in the retina. Therefore, the development of smart nanocarriers for effective or more invasive long-term treatment remains a desirable goal. Recently, approaches have surfaced for the intelligent design of nanocarriers, leveraging specific responses to external or internal triggers and enabling multiple functions for retinal therapy such as topical administration, prolonged drug release, and site-specific drug delivery. This Review provides an overview of prevalent retinal pathologies and related pharmacotherapies to enhance the understanding of retinal diseases. It also surveys recent developments and strategies employed in the intelligent design of nanocarriers for retinal disease. Finally, the challenges of smart nanocarriers in potential clinical retinal therapeutic applications are discussed to inspire the next generation of smart nanocarriers.

Systemic medications for sickle cell disease and potential applications for sickle cell retinopathy.

PURPOSE OF REVIEW: To review the literature evaluating systemic medications for treatment of sickle cell disease (SCD) and their applications for sickle cell retinopathy. RECENT FINDINGS: Prior studies have demonstrated the efficacy of traditional systemic therapies in reducing the risk of development of sickle cell retinopathy. Since 2017, several new and promising disease-modifying therapies for sickle cell disease have been approved for clinical use, including the first genetic therapies such as exagamglogene autotemcel (exa-cel) and lovotibeglogene autotemcel (lovo-cel). These treatments have shown promising results for systemic management but are not widely utilized due to limited access and high cost. The efficacy of these therapies for the prevention of sickle cell retinopathy remains unknown and opens the door to new avenues for research. Furthermore, the role of systemic therapy for the management of hemoglobin SC (HbSC) disease, which has milder systemic effects but higher likelihood of causing retinopathy, remains poorly understood. SUMMARY: Hydroxyurea has been a mainstay of systemic management of SCD with prior work suggesting its ability to reduce the likelihood of developing retinopathy. There are several new and potentially curative systemic therapies for SCD, though their role in retinopathy prevention and management has not been studied extensively. Future studies are necessary to understand the implications of these emerging therapies for sickle cell retinopathy.

Evidence-Based Use of Bevacizumab in the Management of Neovascular Age-Related Macular Degeneration.

Indicated for colorectal cancer for decades, bevacizumab has been widely used off label to treat retinal diseases, and the benefits of its use, specifically in neovascular age-related macular degeneration, have been demonstrated in multiple clinical trials. The intravitreal delivery of bevacizumab requires it to be aseptically repackaged into individual syringes by compounding pharmacies for use in the eye. Although the repackaging process is permitted by the US Food and Drug Administration, the resultant product does not meet the specific standards of products approved for use as ophthalmic injectables nor is the parenteral innovator solution compliant with ophthalmic standards. Studies have also demonstrated variability in the quality and quantity of repackaged bevacizumab. This narrative review summarizes the evidence and discusses the role of off-label bevacizumab in the treatment and management of retinal diseases, its mechanism of action, current challenges and provides a critical appraisal of current evidence, clinical implications, and future directions. [Ophthalmic Surg Lasers Imaging Retina 2024;55:155-162.].

[Iatrogenic retinal defects after intravitreal operative drug injections]. / Iatrogene Netzhautdefekte nach intravitrealer operativer Medikamenteneingabe.

BACKGROUND: Intravitreal operative drug injections represent one of the most frequently performed medical interventions. The risk profile is low. In addition to intraocular pressure elevation, the most frequent complications include exogenous endophthalmitis, vitreous hemorrhage and rhegmatogenous retinal detachment. Furthermore, isolated cases of lens injuries, macular holes associated with vitreoretinal traction and peripheral retinal defects have been described. In the present case series sharp iatrogenic macular and retinal defects are described. METHODS: Retrospective multicenter case collection of patients with iatrogenic retinal defects after intravitreal injections from 2016 to 2023. RESULTS: Iatrogenic retinal trauma after intravitreal injections for treatment of neovascular age-related macular degeneration was identified in 9 cases (72 years ± 8.1, 3 eyes pseudophakic). While sharp injuries within the macula occurred in six cases, extramacular lesions were detected in the other cases. CONCLUSION: Iatrogenic retinal and macular injuries are rare complications of intravitreal injections and when correctly carried out are preventable, especially with respect to use of cannulas and the choice of the distance from the limbus.

Crystalline Retinopathy Following Intravitreal Clindamycin.

This case report describes a 74-year-old woman who developed a crystalline retinopathy following intravitreal injection of clindamycin. The patient presented with ocular toxoplasmosis in the left eye but was allergic to sulfa medications, so she was treated with intravitreal clindamycin. Subsequently, fine refractile yellow-white crystals were observed on examination of the left macula. Optical coherence tomography localized the crystals to the posterior hyaloid. Intravitreal clindamycin should be considered in the differential diagnosis of crystalline retinopathy. [Ophthalmic Surg Lasers Imaging Retina 2024;55:168-170.].

The Effect of S-Allyl L-Cysteine on Retinal Ischemia: The Contributions of MCP-1 and PKM2 in the Underlying Medicinal Properties.

Retinal ischemia plays a vital role in vision-threatening retinal ischemic disorders, such as diabetic retinopathy, age-related macular degeneration, glaucoma, etc. The aim of this study was to investigate the effects of S-allyl L-cysteine (SAC) and its associated therapeutic mechanism. Oxidative stress was induced by administration of 500 µM H2O2 for 24 h; SAC demonstrated a dose-dependent neuroprotective effect with significant cell viability effects at 100 µM, and it concurrently downregulated angiogenesis factor PKM2 and inflammatory biomarker MCP-1. In a Wistar rat model of high intraocular pressure (HIOP)-induced retinal ischemia and reperfusion (I/R), post-administration of 100 µM SAC counteracted the ischemic-associated reduction of ERG b-wave amplitude and fluorogold-labeled RGC reduction. This study supports that SAC could protect against retinal ischemia through its anti-oxidative, anti-angiogenic, anti-inflammatory, and neuroprotective properties.

Nanotechnology in Retinal Disease: Current Concepts and Future Directions.

The retina is one of the most complex and extraordinary human organs affected by genetic, metabolic, and degenerative diseases, resulting in blindness for ∼1.3 million people in the United States and over 40 million people worldwide. This translates into a huge loss of productivity, especially among younger patients with inherited retinal diseases (IRDs) and diabetic retinopathy. Age-related macular degeneration accounts for 90% of all blindness cases worldwide. The prevalence of this condition is projected to reach over 5 million individuals over the next 3 decades. There are also >20 IRD phenotypes, affecting >2 million people worldwide. Nanobiotechnology uses nanotechnology for biological applications, making use of biological materials either conceptually or directly in the fabrication of new materials. Bionanotechnology, on the other hand, uses molecular biology for the purpose of creating nanostructures (ie, structures with at least 1 dimension <100 nm). Retinal applications of these technologies are developing at a rapid pace. This review includes the most current nanotechnological applications in retinal diagnostics, theranostics, drug delivery, and targeting, including the potential for nonviral vehicles such as liposomes, micelles, and dendrimers, which pose advantages over viral vectors in retinal drug delivery. Furthermore, we discuss current and future applications as surgical adjuncts and in regenerative medicine as they pertain to retinal disease. Structure and function of nanoparticles such as carbon nanotubules, quantum dots, and magnetic nanoparticles, as well as diagnostic technologies such as next-generation DNA sequencing and single-molecule bionanosensing, will also be discussed.

Extracellular vesicles in degenerative retinal diseases: A new therapeutic paradigm.

Nanoscale extracellular vesicles (EVs), consisting of exomers, exosomes and microvesicles/ectosomes, have been extensively investigated in the last 20 years, although their biological role is still something of a mystery. EVs are involved in the transfer of lipids, nucleic acids and proteins from donor to recipient cells or distant organs as well as regulating cell-cell communication and signaling. Thus, EVs are important in intercellular communication and this is not limited to sister cells, but may also mediate the crosstalk between different cell types even over long distances. EVs play crucial functions in both cellular homeostasis and the pathogenesis of diseases, and since their contents reflect the status of the donor cell, they represent an additional valuable source of information for characterizing complex biological processes. Recent advances in isolation and analytical methods have led to substantial improvements in both characterizing and engineering EVs, leading to their use either as novel biomarkers for disease diagnosis/prognosis or even as novel therapies. Due to their capacity to carry biomolecules, various EV-based therapeutic applications have been devised for several pathological conditions, including eye diseases. In the eye, EVs have been detected in the retina, aqueous humor, vitreous body and also in tears. Experiences with other forms of intraocular drug applications have opened new ways to use EVs in the treatment of retinal diseases. We here provide a comprehensive summary of the main in vitro, in vivo, and ex vivo literature-based studies on EVs' role in ocular physiological and pathological conditions. We have focused on age-related macular degeneration, diabetic retinopathy, glaucoma, which are common eye diseases leading to permanent blindness, if not treated properly. In addition, the putative use of EVs in retinitis pigmentosa and other retinopathies is discussed. Finally, we have reviewed the potential of EVs as therapeutic tools and/or biomarkers in the above-mentioned retinal disorders. Evidence emerging from experimental disease models and human material strongly suggests future diagnostic and/or therapeutic exploitation of these biological agents in various ocular disorders with a good possibility to improve the patient's quality of life.

Acute posterior multifocal placoid pigment epitheliopathy: clinical presentation and risk of stroke and transient ischaemic attack.

BACKGROUND/AIMS: Acute posterior multifocal placoid pigment epitheliopathy is a rare but important disease that can be associated with life-threatening complications due to cerebral vasculitis. The primary objective was to determine the incidence of neurological complications and risk factors for stroke and transient ischaemic attack (TIA) associated with acute posterior multifocal placoid pigment epitheliopathy. Secondary objectives included the clinical presentation, visual outcomes and recurrence rates. METHODS: This was a multicentre retrospective case series including 111 eyes from 60 subjects presenting from January 2009 to June 2020. RESULTS: Median age at presentation was 29 years (IQR 24.7-35.1) and 36 subjects (60.0%) were male. 20 subjects (33.3%) reported a viral prodrome. Stroke and TIA were observed in seven subjects (11.7%). Older age was the only significant risk factor for stroke/TIA (p=0.042). Vision loss occurred in seven eyes, with four eyes (3.6%) having final visual acuity 6/15-6/60 and three eyes (2.7%) having visual acuity of 6/60 or worse. Recurrence occurred in 10 subjects (16.7%). CONCLUSIONS: The presence of headache cannot reliably predict those at risk of stroke/TIA. Individuals presenting with acute posterior multifocal pigment epitheliopathy should therefore undergo a clinical neurological review and work-up for cerebral vasculitis as deemed appropriate by the treating ophthalmologist and collaborating neurologist.

Effects of hydroxychloroquine therapy on choroidal volume and choroidal vascularity index.

PURPOSE: To determine changes in choroidal volume (CV) and choroidal vascularity index (CVI) in patients on hydroxychloroquine (HCQ) therapy. METHODS: Retrospective analysis of patients on HCQ therapy. CV and CVI were assessed below the central foveal region on spectral-domain optical coherence tomography using an automatic denoising and localization algorithm. CV and CVI were compared with age-matched controls. Regression analyses were performed to generate associations between CV and CVI with demographics and HCQ treatment parameters. Associations were assessed using a generalized estimating equation model adjusted for intra-subject inter-eye correlations. RESULTS: A total of 137 adult patients (23 males and 114 females) were included. Mean age was 45.6 ± 13.7 years and most patients identified as Caucasian (79%). Total duration of HCQ therapy ranged from 3 months to 20 years. Daily HCQ intake varied from 150-600 mg (mean = 304 mg), while cumulative doses ranged from 18-2,800 g. At presentation, the median CV was 0.51 (IQR:0.356-0.747) mm, and median CVI was 0.559 (IQR:0.528-0.578). Increased cumulative HCQ dose was associated with decreased CV (p = 0.006). Compared to age-matched controls, CV, CVI, and luminal area were significantly lower in the study group (p = 0.0003, 0.0001, and 0.0002). CONCLUSION: In this study, we present a novel analysis of key biomarkers which predate the occurrence of HCQ retinopathy. Choroidal volume and vascularity index are significantly reduced in patients on HCQ therapy, especially at higher cumulative doses. These findings suggest new tools to guide medical decision-making for patients receiving HCQ therapy for rheumatologic diseases.

N-Acetylserotonin Alleviates Retinal Autophagy via TrkB/AKT/Nrf2 Signaling Pathway in Retinal Ischemia-Reperfusion Injury Rats.

INTRODUCTION: The objective of this study was to investigate the impact of N-acetylserotonin (NAS) on the autophagy of retinal cells in rats with retinal ischemia-reperfusion injury (RIRI) and to explore the mechanisms by which NAS administration can alleviate RIRI through the tropomyosin-related kinase receptor B (TrkB)/protein kinase B (Akt)/nuclear factor erythroid-derived factor 2-related factor (Nrf2) signaling pathway. METHODS: Healthy adult male rats were randomly assigned to four groups: sham, RIRI, RIRI+NAS, and RIRI+NAS+ANA-12. The RIRI group was induced by elevating intraocular pressure, and changes in retinal structure and edema were assessed using H&E staining. The RIRI+NAS and RIRI+NAS+ANA-12 groups received intraperitoneal injections of NAS before and after modeling. The RIRI+NAS+ANA-12 group was also administered ANA-12, a TrkB antagonist. Immunohistochemical staining and Western blot analysis were used to evaluate phosphorylated TrkB (p-TrkB), phosphorylated Akt (p-Akt), Nrf2, sequestosome 1 (P62), and microtubule-associated protein 1 light chain 3 (LC3-II) levels in the retinas of each group. Electroretinogram was recorded to detect retinal function in each group of rats 24 h after modeling. RESULTS: The RIRI+NAS group had a thinner retina and more retinal ganglion cells (RGCs) than RIRI and RIRI+NAS+ANA-12 groups (p < 0.05). Immunohistochemical staining and Western blot results showed that p-TrkB, p-Akt, n-Nrf2, and P62 levels in the RIRI+NAS group were higher compared with those in RIRI and RIRI+NAS+ANA-12 groups (p < 0.05). Also, lower LC3-II levels were observed in the RIRI+NAS group compared with that in RIRI and RIRI+NAS+ANA-12 groups (p < 0.05). Electroretinogram recording results showed that 24 h after retinal ischemia-reperfusion, the magnitude of b-wave changes was attenuated in the RIRI+NAS group compared with the RIRI group (p < 0.05). CONCLUSION: The administration of NAS activates the TrkB/Akt/Nrf2 signaling pathway, reduces autophagy, alleviates retinal edema, promotes the survival of retinal ganglion cells (RGCs), and provides neuroprotection against retinal injury.

Setanaxib mitigates oxidative damage following retinal ischemia-reperfusion via NOX1 and NOX4 inhibition in retinal ganglion cells.

Glaucoma, a prevalent cause of permanent visual impairment worldwide, is characterized by the progressive degeneration of retinal ganglion cells (RGCs). NADPH oxidase (NOX) 1 and NOX4 are pivotal nodes in various retinal diseases. Setanaxib, a potent and highly selective inhibitor of NOX1 and NOX4, can impede the progression of various diseases. This study investigated the efficacy of setanaxib in ameliorating retinal ischemia-reperfusion (I/R) injury and elucidated its underlying mechanisms. The model of retinal I/R induced by acute intraocular hypertension and the oxygen-glucose deprivation/reoxygenation (OGD/R) model of primary RGCs were established. By suppressing NOX1 and NOX4 expression in RGCs, setanaxib mitigated I/R-induced retinal neuronal loss, structural disruption, and dysfunction. Setanaxib reduced TUNEL-positive cells, upregulated Bcl-2, and inhibited Bax, Bad, and cleaved-caspase-3 overexpression after I/R injury in vitro and in vivo. Moreover, setanaxib also significantly reduced cellular senescence, as demonstrated by downregulating SA-ß-gal-positive and p16-INK4a expression. Furthermore, setanaxib significantly suppressed ROS production, Hif-1α and FOXO1 upregulation, and NRF2 downregulation in damaged RGCs. These findings highlight that the setanaxib effectively inhibited NOX1 and NOX4, thereby regulating ROS production and redox signal activation. This inhibition further prevents the activation of apoptosis and senescence related factors in RGCs, ultimately protecting them against retinal I/R injury. Consequently, setanaxib exhibits promising potential as a therapeutic intervention for glaucoma.

Framboesiform Facial Lesions and Chorioretinopathy as Presenting Signs of Syphilis in an Immunocompetent Patient.

ABSTRACT: Syphilis has long been considered the "great masquerader," notorious for its varying presentations and ability to affect most organ systems in the body. We report the case of a 41-year-old immunocompetent man who presented to ophthalmology with rapidly progressive visual complaints from bilateral panuveitis and concomitant verrucous facial lesions initially disregarded by the patient as acne. Serum testing for syphilis was positive, and he was admitted for 14 days of intravenous (IV) penicillin with multiservice care from dermatology, ophthalmology, and infectious disease. We present photographic documentation showing his stepwise resolution of his facial and retinal involvement with penicillin treatment course. This case is unusual in the concomitant presentation of ocular and facial syphilitic findings in an immunocompetent patient and highlights the need to include syphilis in the differential for unusual appearances.

Tamoxifen retinopathy: A comprehensive review.

Tamoxifen is a selective estrogen receptor modulator used mainly for the treatment of breast cancer. Based on the case reports and studies performed to date on the retinal toxicity of tamoxifen, retinopathy appears to occur in as many as 12% of patients taking 20 mg tamoxifen a day for over 2 years. Of this 12%, as many as half develop symptomatic changes in visual acuity. Retinal changes consist primarily of crystalline deposits, cystoid macular edema, hyperreflective deposits in the inner retinal layers, and telangiectasia. Tamoxifen retinopathy is currently managed by discontinuing tamoxifen therapy as the cancer prognosis permits; however, discontinuing therapy demonstrates little to no improvement in visual acuity once visual changes have taken place. Intravitreal injections of steroids or antivascular endothelial growth factor therapy have been performed, but require further studying before conclusions can be made. Until then, optical coherence tomography screening for retinal changes should be performed every 6 months for patients who have been on tamoxifen therapy for 2 years or more. This way, patients can become aware of retinal changes, and their physicians can consider adjusting tamoxifen therapy before they risk developing changes in visual acuity.