ARTICLE | doi:10.20944/preprints202106.0585.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: Triamcinolone acetonide; Liposomes; Neovascular age related macular degeneration; Wet macular degeneration; Adjuvant therapy; Ranibizumab
Online: 23 June 2021 (12:56:55 CEST)
Novel strategies have been developed to reduce or to avoid the intravitreal injections (IVTs) of the antiangiogenic (ranibizumab; RBZ) and the anti-inflammatory (triamcinolone acetonide; TA) agents used to treat vitreoretinal diseases. One of the strategies include liposomes. In this study, it was evaluated the safety and efficacy of topical triamcinolone-loaded liposomes formulation (TALF) as an adjuvant to intravitreal RBZ therapy in treatment-naive patients with neovascular age related macular degeneration (nAMD). Subjects were randomly assigned to the RBZ-TALF or the RBZ-pro re nata (RBZ-PRN) group. Patients from the RBZ-TALF group were instructed to apply TALF for a 12-month period after a single dose of RBZ. Patients from the RBZ-PRN group received three monthly RBZ-IVTs. Retreatment with RBZ was considered in case of nAMD reactivation. Related to safety, non-ocular abnormalities were observed during TALF therapy. Owing to the efficacy, non-significant differences are identified in visual acuity or central foveal thickness when the RBZ-PRN and RBZ-TALF groups are compared. Importantly the average number of RBZ injections was significantly lower in the RBZ-TALF group (2.5 ± 1.4 vs 6.1 ± 1.3 IVTs; p=0004). Therefore, TALF used as an adjuvant to RBZ reduce the number of RBZ-IVTs retreatment with optimal visual and anatomic results.
ARTICLE | doi:10.20944/preprints202010.0009.v1
Subject: Social Sciences, Psychology Keywords: visual search; vision loss; incidental learning; macular degeneration; fovea
Online: 1 October 2020 (09:12:00 CEST)
Foveal vision loss has been shown to reduce efficient visual search guidance due to contextual cueing by incidentally learned contexts. However, previous studies used artificial (T among L-shape) search paradigms that prevent the memorization of a target in a semantically meaningful scene. Here, we investigated contextual cueing in real-life scenes that allow explicit memory of target locations in semantically rich scenes. In contrast to the contextual cueing deficits in artificial scenes, contextual cueing in patients with age-related macular degeneration (AMD) did not differ from age-matched normal-sighted controls. We discuss this in the context of visuospatial working memory demands for which both eye-movement control in the presence of central vision loss and for memory-guided search may compete. Memory-guided search in semantically rich scenes may depend less on visuospatial working memory than search in abstract displays, potentially explaining intact contextual cueing in the former but not the latter. In a practical sense, our findings may indicate that Patients with AMD are less deficient than expected after previous lab experiments. This shows the usefulness of realistic stimuli in experimental clinical research.
REVIEW | doi:10.20944/preprints202211.0350.v2
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Proteomics, Age-related macular degeneration, inflammation, biomarker, oxidative stress.
Online: 21 November 2022 (02:35:09 CET)
Age-related macular degeneration (AMD) is a common ocular disease characterized by the de-generation of the central area of the retina in elderly population. Progression and response to treatment is influenced by genetic and non-genetic factors. Proteomics is a powerful tool to study, at the molecular level, the mechanisms underlaying the progression of the diseases, to identify new therapeutical targets and to establish biomarkers to monitor progression and treatment ef-fectiveness. In this work we pursue to systematically review the use of proteomic-based ap-proaches for the study of the molecular mechanisms underlying the development of AMD, as well as the progression of the disease and the on-treatment patient monitoring. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guidelines were followed. Proteomic approaches have identified key players on the onset of the disease, such as proteins involved in lipid metabolism and oxidative stress, but also in the progression to advanced stages, including factors related to extracellular matrix integrity and angiogenesis. Although an-ti-vascular endothelial growth factor (anti-VEGF)-based therapy has been crucial in the treatment of neovascular AMD it is necessary to get deeper into the underlying disease mechanisms to move forward to next-generation therapies of the later-stage forms of this multifactorial disease.
ARTICLE | doi:10.20944/preprints202205.0224.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: age-related macular degeneration; light-induced photoreceptor degeneration; anti-inflammatory drug; toll-like receptor 4
Online: 17 May 2022 (08:03:11 CEST)
Age-related macular degeneration is a progressive retinal disease that is associated with factors such as oxidative stress, decreased phagocytic activity, and inflammation. In this study, we evaluated the protective effects of SIG-1451, a non-steroidal anti-inflammatory drug developed for treating atopic dermatitis and known to inhibit toll-like receptor 4, on light-induced photoreceptor degeneration. SIG-1451 was intraperitoneally injected into rats once a day before exposure to 1000 lx light for 24 h; one day later, optical coherence tomography showed a decrease in retinal thickness, and electroretinogram (ERG) amplitude was also found to have decreased 3 d after light exposure. Moreover, SIG-1451 protected against this decrease in retinal thickness and increase in ERG am-plitude. One day after light exposure, upregulation of inflammatory response-related genes was observed, and SIG-1451 was found to inhibit this upregulation. Iba-1, a microglial marker, was suppressed in SIG-1451-injected rats. To investigate the molecular mechanism underlying these effects, we used lipopolysaccharide (LPS)-stimulated rat immortalised Müller cells. The upregu-lation of C-C motif chemokine 2 by LPS stimulation was significantly inhibited by SIG-1451 treatment, and western blot analysis revealed a decrease in phosphorylated I-κB levels. These results indicate that SIG-1451 protects photoreceptor cells by attenuating light damage progression through inhibiting inflammatory responses.
ARTICLE | doi:10.20944/preprints202306.0061.v1
Subject: Medicine And Pharmacology, Ophthalmology Keywords: neovascular age-related macular degeneration; visual outcomes; anti-VEGF; visual impairment; population-based cohort
Online: 1 June 2023 (08:10:15 CEST)
Neovascular age-related macular degeneration (nAMD) leads to visual impairment if not treated timely. Intravitreal anti-VEGF drugs have revolutionized nAMD treatment in two decades. We evaluated visual outcomes of anti-VEGF treatment in nAMD. A real-life population-based cohort study. Data included parameters for age, sex, age at the diagnosis, laterality, chronicity, symptoms, visual outcomes, lens status, and history of intravitreal injections. A total of 1088 eyes (827 patients) with nAMD were included. Visual acuity was stable or improved in 984 eyes (90%) after an average 36±25 months follow-up. Bevacitzumab was the first-line drug in 1083 (99.5%) eyes. Vision improved ≥15 ETDRS letters in 377 (35%), > 5 ETDRS letters in 309 (28%) and was stable (±5 ETDRS letters) in 298 (27%) eyes after anti-VEGF treatment. The loss of 5-<15 ETDRS letters in 44 (4%) and ≥15 ETDRS letters in 60 (6%) eyes was noted. At the diagnosis of nAMD, 110 out of 827 patients (13%) fulfilled the criteria of visual impairment, whereas 179 patients (22%) were visually impaired after the follow-up. Improvement or stabilization in vision was noted in 90% of the anti-VEGF-treated eyes with nAMD. In addition, anti-VEGF agents are crucial in diminishing nAMD-related visual impairment.
ARTICLE | doi:10.20944/preprints202211.0392.v2
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: Age-related Macular Degeneration; Artificial Intelligence; Machine Learning; Optical Coherence Tomography; Fundus Autofluorescence; regular fundus photography; Ultra-Widefield Fundus
Online: 8 May 2023 (14:25:29 CEST)
Age-related Macular Degeneration (AMD) is the major cause of elders’ vision loss, early screening and treatment are the most efficient way to reduce the rate of blindness. AI-based methods based on ophthalmic images play great potential for AMD diagnosis. However, low levels of accuracy, robustness, and explainability are challenges for AI approaches applied in clinics. Thus, this study proposed a multi-type of data source fusion method and a multi-model fusion approach for AMD detection. Typical unsupervised (Hierarchical Clustering and K-Means), typical supervised (SVM, VGG-16, and ResNet) methods, and proposed methods (multi-source data fusion-based method and multi-model fusion-based approach) are compared based on Optical Coherence Tomography (OCT), Fundus Autofluorescence (FAF), regular color fundus photography (CFP) and Ultra-Wide field Fundus (UWF) images. Data preprocessing and enhancements of each type of data are discussed. A feature extraction based on unsupervised ML models, feature combination and normalization, and multi-layer perception (MLP) algorithm are involved in the proposed multi-source data fusion-based method. Supervised ML and DL models and a voting mechanism are involved in the multi-model fusion-based approach. Findings show that the proposed methods present a high performance of accuracy and robustness. A real-world UWF database is involved from Shenzhen Aier Hospital. Practical and theoretical contributions are delivered. A reference value for medical diagnosis based on multiple digital images is contributed.
REVIEW | doi:10.20944/preprints201902.0101.v1
Subject: Medicine And Pharmacology, Ophthalmology Keywords: age-related macular degeneration; anti-inflammatory agents; dry AMD; geographic atrophy; intravitreal injection; complement inhibitors; neuroprotective agents; non-exudative AMD
Online: 12 February 2019 (11:00:52 CET)
The present review focuses on recent clinical trials that analyze the efficacy of intravitreal therapeutic agents for the treatment of dry age-related macular degeneration (AMD), such as neuroprotective drugs, and complement inhibitors, also called immunomodulatory or anti-inflammatory. A systematic literature search was performed to identify randomized controlled trials published prior to January 2019. Patients affected by dry AMD treated with intravitreal therapeutic agents were included. The changes in the correct visual acuity and the reduction in geographic atrophy progression were evaluated. Several new drugs have shown some promising results, including those targeting the complement cascade and agents called neuroprotective. The action potential of the two groups of drugs is to block the complement cascade model for immunomodulating agents, and prevent the degeneration and apoptosis of ganglion cells for the neuroprotectors, respectively. To the best of knowledge, and after extensive studies on the matter, there are still many investigations to be carried out on dry AMD in collaboration between researchers. They will have to identify truly effective molecules, understand the practical potential of pluripotent stem cells, and refine gene therapies. Only in-depth clinical trials will be able to allow the most appropriate and personalized treatments for each dry AMD patient.
REVIEW | doi:10.20944/preprints201810.0369.v1
Subject: Medicine And Pharmacology, Dietetics And Nutrition Keywords: Age-Related Macular Degeneration, Gut-retina axis, Gut microbiota, Dietary habits, Micronutrients, Fish oil, omega-3 Polyunsaturated fatty acids, Personalised medicine
Online: 16 October 2018 (17:39:27 CEST)
Age-related macular degeneration (AMD) is a complex multifactorial disease and the primary cause of legal and irreversible blindness among individuals aged >=65 years in developed countries. Globally, it affects 30-50 million individuals, with an estimated increase of approximately 200 million by 2020 and approximately 300 million by 2040. Currently, the neovascular form may be able to be treated with the use of anti-VEGF drugs, while no effective treatments are available for the dry form. Many observational studies, such as AREDS-1 and AREDS 2, have shown a potential role of micronutrient supplementation in lowering the risk of progression of the early stages of AMD. Recently, low-grade inflammation, sustained by dysbiosis and a leaky gut, has been shown to contribute to the development of AMD. Given the ascertained influence of the gut microbiota in systemic low-grade inflammation and its potential modulation by macro- and micro-nutrients, a potential role of diet in AMD has been proposed. This review discusses the role of the gut microbiota in the development of AMD. Using PubMed, Web of Science and Scopus, we searched for recent scientific evidence discussing the impact of dietary habits (high fat and high glucose or fructose diets), micronutrients (vitamins C, E, and D, zinc, beta-carotene, lutein and zeaxanthin) and omega-3 fatty acids on the modulation of the gut microbiota and their relationship with AMD risk and progression.
ARTICLE | doi:10.20944/preprints202305.1080.v1
Subject: Medicine And Pharmacology, Ophthalmology Keywords: diabetic macular edema; diabetes; visual acuity; optical coherence tomography; macular thickness; retinal thickness; anti-VEGF; corticosteroid; deviation
Online: 16 May 2023 (04:43:23 CEST)
The purpose of the study was to determine the “retinal thickness deviation” (RTD) in diabetic macular edema (DME) eyes treated with intravitreal therapy and to establish associations be-tween RTD and best-corrected visual acuity (BCVA). We conducted a retrospective study, in-cluding consecutive DME eyes undergoing intravitreal therapy with two years of follow-up. BCVA and central subfield thickness (CST) were collected at baseline, 12 months and 24 months of follow-up. RTD was calculated as the absolute difference between measured and normative CST values at each time point. Linear regression analyses were performed between RTD and BCVA and between CST and BCVA. One hundred and four eyes were included in the analysis. The RTD was 177.0 (117.2) μm at baseline, 97.0 (99.7) μm at 12 months and 89.9 (75.3) μm at 24 months of follow-up (P < .001). RTD showed a moderate association with BCVA at baseline (R2=0.134, p<0.001) and 12 months (R2=0.197, p<0.001), and a substantial association at 24 months (R2=0.272, p<0.001). The CST showed a moderate association with BCVA at baseline (R2=0.132, p<0.001) and 12 months (R2=0.136, p<0.001), while the association was weak at 24 months (R2=0.065, p=0.009). In conclusion, RTD showed a good association with visual outcome in DME eyes undergoing intravitreal treatment.
ARTICLE | doi:10.20944/preprints202211.0274.v1
Subject: Medicine And Pharmacology, Ophthalmology Keywords: telemedicine; diabetic retinopathy; diabetic macular edema; epidemiology; COVID-19
Online: 15 November 2022 (04:40:58 CET)
(1) Background: Diabetic retinopathy (DR) is a complication of diabetes mellitus (DM) and the COVID-19 pandemic has affected screening programmes. The aim of present study was to determine the impact of the COVID-19 pandemic on the screening of diabetes patients in our Health Care Area (HCA); (2) Methods: A retrospective study of patients with DM who had attended the DR screening programme between January 2015 and June 2022. We studied attendance, DM metabolic control and DR incidence. (3) Results: Screening for DR decreased in the first months of the pandemic. Incidence of mild and moderate DR remained stable throughout the study, and we observed a little increase in severe-DR, proliferative-DR and neovascular glaucoma, during 2021 and 2022. (4) Conclusions: The COVID-19 pandemic caused a reduction in the number of patients screened for DM, although its effect on DR seems limited, with a similar number of patients with DR throughout 2015 to 2022, despite the number of patients with severe-DR and proliferative-DR increased in 2021 and 2022.
ARTICLE | doi:10.20944/preprints201807.0347.v2
Subject: Medicine And Pharmacology, Ophthalmology Keywords: choroidal neovascularization; neovascular age-related macular degeneration; calreticulin anti-angiogenic domain
Online: 18 September 2018 (06:27:47 CEST)
Choroidal neovascularization (CNV) is a key pathological feature of several of the leading causes of vision loss including neovascular age-related macular degeneration. Here we show that a calreticulin anti-angiogenic domain (CAD)-like peptide 27, CAD27, inhibited in vitro angiogenic activities, including tube formation and migration of endothelial cells, and suppressed vascular sprouting from rat aortic ring explants. In rat model of laser-induced CNV, we demonstrate that intravitreal injection of CAD27 significantly attenuated the formation of CNV lesions as measured via fundus fluorescein angiography and choroid flat-mounts (19.5% and 22.4% reductions at 10μg and 20μg of CAD27 injected, respectively). Similarly, the reduction of CNV lesions was observed in the groups of rats that had received topical applications of CAD27 (choroid flat-mounts: 17.9% and 32.5% reductions at 10μg/mL and 20μg/mL of CAD27 installed, respectively). Retinal function was unaffected, as measured using electroretinography in both groups received interareal injection or topical applications of CAD27 at least for 9 days. These findings show that CAD27 can be used as a potential therapeutic alternative for targeting CNV in the diseases such as neovascular age-related macular degeneration.
REVIEW | doi:10.20944/preprints202302.0147.v1
Subject: Medicine And Pharmacology, Ophthalmology Keywords: Ophthalmic imaging; Optical coherence tomography; Age-related macular degeneration; Glaucoma; Retinal conditions
Online: 8 February 2023 (11:28:28 CET)
OCTA is an imaging modality used in the assessment of the retinal vasculature. It operates on the principle of coherence tomography used in standard OCT with the addition of delineating the retinal vascular. This provides a modern non-invasive retinal vascular imaging method compared to conventional dye-based imaging. High quality depth resolution of the superficial and deep capillary networks is possible on OCTA whereas this was not possible prior. OCTA may be limited by image quality degradation from factors such as motion artefact or media opacities, and therefore may not be the investigation of choice for all patient groups. There are multiple potential clinical applications for OCTA in retinal and choroidal vascular disease. Ongoing research is necessary to substantiate the more widespread use of OCTA due to its significant cost burden compared to current modalities.
ARTICLE | doi:10.20944/preprints202206.0170.v1
Subject: Medicine And Pharmacology, Ophthalmology Keywords: Fluid gas exchange; flap closure; idiopathic macular hole; vitrectomy; inverted internal limiting membrane flap technique
Online: 13 June 2022 (05:35:46 CEST)
Purpose: We evaluated the outcomes of fluid-gas exchange (FGE) for long-term flap closure of idiopathic macular hole (MH) after the inverted internal limiting (ILM) flap technique. Methods: We included eyes showed flap closure without complete MH closure, connection of the apart macular tissue, 1 month postoperatively after the inverted ILM flap technique. The eyes stayed at flap closure at 2 months postoperatively further underwent in-office FGE with 16% C3F8. Results: Among 10 eyes, 5 eyes (50%) showed flap closure at 2 months postoperatively further underwent FGE for complete MH closure while the remaining 5 eyes (50%) progressed directly at 2 months postoperatively. The improvement in vision of all flap closure from baseline was significant (p=0.015), with the mean baseline vision was 1.19 [Snellen equivalent (SE), 20/307] ± 0.52 logMAR and the mean final vision being 0.63 (SE, 20/85) ± 0.38 logMAR. The group that underwent FGE showed a better final vision of 0.45 (SE, 20/75) ± 0.23 logMAR than the group that didn’t undergo FGE (0.81 [SE, 20/128] ±0.44 logMAR). All eyes achieved complete MH closure, including the eyes that underwent FGE in a mean period of 5.60 months (range 3-10 months) after the inverted ILM flap technique. The eyes that underwent FGE achieved higher rate of foveal restoration [complete external limiting membrane (ELM): 80%; complete ellipsoid zone (EZ): 60%] than those that didn’t receive FGE (complete ELM: 40%; complete EZ: 10%). Conclusions: Eyes that underwent FGE accelerated complete MH closure and showed better final vision and fovea l restoration.
REVIEW | doi:10.20944/preprints202102.0184.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Retinal degenerative diseases; Age related macular degeneration; Biomaterials, Stem cells, Retinal pigment epithelium; Tissue engineering
Online: 8 February 2021 (10:46:50 CET)
The retina is a complex and fragile photosensitive part of the central nervous system which is prone to degenerative diseases leading to permanent vision loss. No proven treatment strategies exist to treat or reverse the degenerative conditions. Recent investigations demonstrate that cell transplantation therapies to replace the dysfunctional retinal pigment epithelial (RPE) cells and or the degenerating photoreceptors (PRs) are viable options to restore vision. Pluripotent stem cells, retinal progenitor cells and somatic stem cells are the main cell sources used for cell transplantation therapies. The success of retinal transplantation based on cell suspension injection is hindered by limited cell survival and lack of cellular integration. Recent advances in material science helped to develop strategies to grow cells as intact monolayers or as sheets on biomaterial scaffolds for transplantation into the eyes. Such implants are found to be more promising than the bolus injection approach. Tissue engineering techniques are specifically designed to construct biodegradable or non-degradable polymer scaffolds to grow cells as a monolayer and construct implantable grafts. The engineered cell construct along with the extracellular matrix formed, can hold the cells in place to enable easy survival, better integration and improved visual function. This article reviews the advances in the use of scaffolds for transplantation studies in animal models and its application in current clinical trials.
REVIEW | doi:10.20944/preprints201801.0269.v1
Subject: Medicine And Pharmacology, Ophthalmology Keywords: Retinal Pigment Epithelium (RPE); endosomes; phagosomes; lysosomes, autophagy; RPE cultures; Age-related Macular Degeneration (AMD)
Online: 29 January 2018 (08:07:19 CET)
Chronic degeneration of the Retinal Pigment Epithelium (RPE) is a precursor to pathological changes in the outer retina. The RPE monolayer, which lies beneath the neuroretina, daily internalises and digests large volumes of spent photoreceptor outer segments. Impaired cargo handling and processing in the endocytic/phagosome and autophagy pathways leads to the accumulation of lipofuscin and N-retinylidene-N-retinylethanolamine aggregates and chemically-modified compounds such as malondialdehyde and 4-hydroxynonenal within RPE. These contribute to increased proteolytic and oxidative stress, resulting in irreversible damage to post-mitotic RPE cells and development of blinding conditions such as Age-related Macular Degeneration, Stargardt disease and Choroideremia. Here, we review how impaired cargo handling in the RPE results in their dysfunction, discuss new findings from our laboratory and consider how newly discovered roles for lysosomes and the autophagy pathway could provide insights into retinopathies. Studies of these dynamic, molecular events have also been spurred on by recent advances in optics and imaging technology. Mechanisms underpinning lysosomal impairment in other degenerative conditions including storage disorders, a-synuclein pathologies and Alzheimer’s disease are also discussed. Collectively, these findings help transcend conventional understanding of these intracellular compartments as simple waste disposal bags to bring about a paradigm shift in the way lysosomes are perceived.
ARTICLE | doi:10.20944/preprints202104.0066.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: carotenoid; lutein; zexanthin; dehydrolutein; retina; retinal pigment epithelium; singlet oxygen; photosensitized oxidation; age-related macular degeneration.
Online: 2 April 2021 (14:04:44 CEST)
Dehydrolutein accumulates in substantial concentrations in the retina. The aim of this study was to compare antioxidant properties of dehydrolutein with other retinal carotenoids, lutein and zeaxanthin, and their effects on ARPE-19 cells. The time-resolved detection of characteristic singlet oxygen phosphorescence was used to compare the singlet oxygen quenching rate constants of dehydrolutein, lutein, and zeaxanthin. The effects of these carotenoids on photosensitized oxidation were tested in liposomes, where photooxidation was induced by light in the presence of photosensitizers, and monitored by oximetry. To compare the uptake of dehydrolutein, lutein, and zeaxanthin, ARPE-19 cells were incubated with carotenoids for up to 19 days, and carotenoid contents were determined by spectrophotometry in cell extracts. To investigate the effects of carotenoids on phototocytotoxicity, cells were exposed to light in the presence of rose bengal or all-trans-retinal. The results demonstrate that the rate constants for singlet oxygen quenching are 0.77x1010, 0.55x1010, and 1.23x1010 M-1s-1 for dehydrolutein, lutein and zeaxanthin, respectively. Overall, dehydrolutein is similar to lutein or zeaxanthin in protection of lipids against photosensitized oxidation. ARPE-19 cells accumulate substantial amounts of both zeaxanthin and lutein but no detectable amounts of dehydrolutein. Cells pre-incubated with carotenoids are equally susceptible to photosensitized damage as cells without carotenoids. Carotenoids provided to cells together with the extracellular photosensitizers offer partial protection against photodamage. In conclusion, the antioxidant properties of dehydrolutein are similar to lutein and zeaxanthin. The mechanism responsible for its lack of accumulation in ARPE-19 cells deserves further investigation.
ARTICLE | doi:10.20944/preprints202101.0478.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: ocular drug delivery system; topical liposomes; posterior segment of the eye; safety and toler-ability; biologic activity; diabetic macular edema
Online: 25 January 2021 (10:48:51 CET)
Intravitreal injections (IVTs) of corticosteroids as triamcinolone acetonide (TA) are frequently used for the treatment of many vitreous and retinal disorders. However, IVTs are related to severe ocular complications. Lately, a topical ophthalmic TA loaded liposomes formulation (TALF) was designed to transport TA into the posterior segment of the eye when instilled in the ocular surface. To evaluate the safety, tolerability, and biologic activity of TALF, an animal study and a phase I clinical assay was performed. Moreover, four patients with diabetic macular edema (DME) were treated with TALF in order to explore the biologic activity of the formulation. No inflammation, lens opacity, swelling or intraocular pressure rising were recorded after the instillation of TALF in any of the animal or clinical study. Mainly, mild and transient adverse events such as dry eye (30%) and burning (30%) were reported. TALF improves significantly visual acuity and diminishes central foveal thickness in patients with DME. The current data demonstrate the safety, tolerability, and biologic activity of TALF. It seems that TALF can be used topically to treat vitreous and retinal diseases that respond to TA such as DME, avoiding the use of corticosteroids IVTs and its associated hazards.
ARTICLE | doi:10.20944/preprints202305.0723.v1
Subject: Medicine And Pharmacology, Ophthalmology Keywords: retina organ culture; neuroretinal degenerative disease; oxidative stress; antioxidant; age-related macular degeneration (AMD); diabetic retinopathy (DR); Scutellarin; PEDF; GM-CSF; 4R
Online: 10 May 2023 (09:42:33 CEST)
Oxidative stress (OS) is involved in the pathogenesis of retinal neurodegenerative diseases like age-related macular degeneration (AMD) and diabetic retinopathy (DR) and an important target of therapeutic treatments. New therapeutics are tested in vivo despite limits in transferability and ethical concerns. Retina cultures using human tissue can deliver critical information and significantly reduce the number of animal experiments along with increased transferability. We cultured up to 32 retina samples derived from one eye, analyzed models’ quality, induced OS, and tested efficiency of antioxidative therapeutics. Bovine, porcine, rat, and human retinae were cultured in different experimental settings for 3-14 d. OS was induced by high-glucose or hydrogen peroxide (H2O2) and treated by Scutellarin, pigment epithelium-derived factor (PEDF), and/or granulocyte macrophage-colony stimulating factor (GM-CSF). Tissue morphology, cell viability, inflammation, and glutathione level were determined. Retina samples showed only moderate necrosis (23.83±5.05 increased to 27.00±1.66 AU PI-staining over 14 d) after 14 days in culture. OS was successfully induced (reduced ATP content of 288.3±59.9 vs. 435.7±166.8 nM ATP in controls); antioxidants reduced OS-induced apoptosis (from 124.20±51.09 to 60.80±319.66 cells/image after scutellarin-treatment). Enhanced mammalian animal and human retina cultures allow reliable, highly transferable research on OS-triggered age-related diseases and pre-clinical testing during drug development.
ARTICLE | doi:10.20944/preprints202301.0094.v1
Subject: Biology And Life Sciences, Cell And Developmental Biology Keywords: Retinal pigment epithelium of the eye; RPE; AMD (Age-related Macular Degeneration); GPR143; L-DOPA; Melanin; Ocular albinism; Exosome; Photoreceptor outer segment; Cathepsin D.
Online: 5 January 2023 (02:58:31 CET)
Age-related macular degeneration is one of the most common causes of blindness, and the incidence exhibits profound racial bias, occurring most frequently in Caucasians. A primary cell type affected in the disease is the retinal pigment epithelium, but the etiology is unclear. The end 10% of the photoreceptor outer segments are shed each day, and the underlying retinal pigment epithelium engulfs, digests, and recycles molecules back to the sensory retina. In previous work, we showed that GPR143 signaling in response to L-DOPA may be effective in the prevention or delay of age-related macular degeneration. In this study, we explore a novel potential effector of GPR143 signaling, that of outer segment uptake and digestion. Using isolated outer segments, labelled with a pH-sensitive marker to fluoresce in lysosomes, we show that GPR143 signaling does not impact outer segment uptake, but does have a significant effect on subsequent degradation. Interestingly, GPR143 signaling did not affect the digestive capacity of the cells, marked by total proteolytic capacity and cathepsin D activity. Rather, our data suggest GPR143 improved endosomal trafficking efficiency of the phagocytosed outer segments to the lysosome. This result is similar to the effect we previously reported for GPR143 on exosome release from the endosomal compartment. Our data illustrate that GPR143 is active in endosomal traffic A single paragraph of about 200 words maximum. For research articles, abstracts should give a pertinent overview of the work. We strongly encourage authors to use the following style of structured abstracts, but without headings: (1) Background: Place the question addressed in a broad context and highlight the purpose of the study; (2) Methods: briefly describe the main methods or treatments applied; (3) Results: summarize the article’s main findings; (4) Conclusions: indicate the main conclusions or interpretations. The abstract should be an objective representation of the article and it must not contain results that are not presented and substantiated in the main text and should not exaggerate the main conclusions.
REVIEW | doi:10.20944/preprints202303.0500.v1
Subject: Medicine And Pharmacology, Ophthalmology Keywords: Oxidative stress and cell death; Reactive oxygen species; ROS; ROS cell death; autophagy; role of antioxidants; eye disease; cornea; lens; epithelium; retinal ganglion cells; retinal pigment epithelium; macular degeneration; antioxidants in the macula; oxidative stress prevention with antioxidants; lifestyle changes; digital eye strain; glaucoma; cataracts; dry eye disease; computer vision syndrome; digital eye strain; diabetic retinopathy; Vitamin A; Vitamin C; copper; glutathione; zinc; selenium; magnesium; blue light damage; UV light damage; blue light reactive oxygen species; autophagy; ferroptosis; ROS cell death; superoxide dismutase; optic nerve gliomas; food deserts; myopia; free radicals
Online: 29 March 2023 (03:33:55 CEST)
Increased screen time during the COVID-19 pandemic and the accelerated incorporation of technology into daily practices have directly contributed to the increased prevalence of eye disease. The human eye is not built for continual technological use and must adjust to exposure to digital screens. Overexposure to technology can result in eye strain and an increased risk of eye diseases such as myopia with complications later in life, including retinal tears, cataracts, and macular degeneration. As vision and ocular diseases become more prevalent, the study of eye diseases, including their causes and treatments, is especially relevant. There is a need to prevent ocular diseases before they become a burden to individuals, their families, and their communities by better understanding the pathophysiology of ocular diseases. Several ocular diseases are thought to be caused by imbalances in reactive oxygen species (ROS) and autophagy. ROS refers to a class of highly reactive oxygen-containing molecules that can undergo damaging reactions with other molecules in the cell. Autophagy is a cellular process of self-eating whereby damaged, harmful, or dead material in cells is broken down to maintain cellular homeostasis. This paper discusses the role of ROS and autophagy in the pathogenesis of computer vision syndrome (CVS), digital eye strain (DES), myopia, cataracts, glaucoma, diabetic retinopathy (DR), age-related macular degeneration (AMD), optic nerve crush injury (OCN), optic nerve gliomas, and retinoblastoma. Lifestyle changes such as limiting screen time, ensuring adequate exposure to evening sunlight, and using blue light protection measures or protective eyewear are important in the prevention of eye disease. Nutrition also contributes significantly to eye health. A balanced diet rich in vitamins and antioxidants may help to prevent ROS and autophagy imbalance-induced eye disease. Medical and surgical treatments become necessary when preventative measures fail. This paper also addresses how government measures to decrease the onset of eye disease, including targeted programs to increase access to fresh vegetables and fruits in food deserts, are a critical macro-level avenue to reduce eye disease prevalence in the US, which according to the National Eye Institute, costs $139 billion yearly.