Efficacy and safety of intravitreal HLX04-O,an anti-VEGF monoclonal antibody,for the treatment of wet age-related macular degeneration

·AIM:To evaluate the efficacy and safety of HLX04-O,an investigational ophthalmic formulation of HLX04(bevacizumab biosimilar)for intravitreal injection,as a treatment for wet age-related macular degeneration(wAMD)in a phase 1/2 clinical trial(NCT04993352).·METHODS:Eligible patients with wAMD were enrolled to receive HLX04-O intravitreal injections at a dose of1.25 mg/0.05 mL every four weeks.Efficacy and adverse events were evaluated every month during study visits.·RESULTS:A 76-year-old male with wAMD in his left eye participated in the trial and completed six cycles of HLX04-O intravitreal injections.Changes were observed in macular center point thickness(baseline vs last study visit,437 vs 255μm)and best-corrected visual acuity letter score(baseline vs last study visit,36 vs 77)of the affected eye,which indicated an improvement in wAMD over treatment.No adverse events were reported by the data cutoff date.·CONCLUSION:HLX04-O at 1.25 mg/0.05 mL every four weeks is well tolerated in this patient,demonstrating promising safety and efficacy in wAMD treatment.Largescale studies are required to confirm the outcomes.

Biomaterial engineering strategies for modeling the Bruch's membrane in age-related macular degeneration

Age-related macular degeneration,a multifactorial inflammatory degenerative retinal disease,ranks as the leading cause of blindness in the elderly.Strikingly,there is a scarcity of curative therapies,especially for the atrophic advanced form of age-related macular degeneration,likely due to the lack of models able to fully recapitulate the native structure of the outer blood retinal barrier,the prime to rget tissue of age-related macular degeneration.Standard in vitro systems rely on 2D monocultures unable to adequately reproduce the structure and function of the outer blood retinal barrier,integrated by the dynamic interaction of the retinal pigment epithelium,the Bruch's membrane,and the underlying choriocapillaris.The Bruch's membrane provides structu ral and mechanical support and regulates the molecular trafficking in the outer blood retinal barrier,and therefo re adequate Bruch's membrane-mimics are key for the development of physiologically relevant models of the outer blood retinal barrie r.In the last years,advances in the field of biomaterial engineering have provided novel approaches to mimic the Bruch's membrane from a variety of materials.This review provides a discussion of the integrated properties and function of outer blood retinal barrier components in healt hy and age-related macular degeneration status to understand the requirements to adequately fabricate Bruch's membrane biomimetic systems.Then,we discuss novel materials and techniques to fabricate Bruch's membrane-like scaffolds for age-related macular degeneration in vitro modeling,discussing their advantages and challenges with a special focus on the potential of Bruch's membrane-like mimics based on decellularized tissue.

NLRP3 and autophagy in retinal ganglion cell inflammation in age-related macular degeneration:potential therapeutic implications

Retinal degenerative diseases were a large group of diseases characterized by the primary death of retinal ganglion cells(RGCs).Recent studies had shown an interaction between autophagy and nucleotide-binding oligomerization domain-like receptor 3(NLRP3)inflammasomes,which may affect RGCs in retinal degenerative diseases.The NLRP3 inflammasome was a protein complex that,upon activation,produces caspase-1,mediating the apoptosis of retinal cells and promoting the occurrence and development of retinal degenerative diseases.Upregulated autophagy could inhibit NLRP3 inflammasome activation,while inhibited autophagy can promote NLRP3 inflammasome activation,which leaded to the accelerated emergence of drusen and lipofuscin deposition under the neurosensory retina.The activated NLRP3 inflammasome could further inhibit autophagy,thus forming a vicious cycle that accelerated the damage and death of RGCs.This review discussed the relationship between NLRP3 inflammasome and autophagy and its effects on RGCs in age-related macular degeneration,providing a new perspective and direction for the treatment of retinal diseases.

HCSP-Net:A Novel Model of Age-Related Macular Degeneration Classification Based on Color Fundus Photography

Age-related macular degeneration(AMD)ranks third among the most common causes of blindness.As the most conventional and direct method for identifying AMD,color fundus photography has become prominent owing to its consistency,ease of use,and good quality in extensive clinical practice.In this study,a convolutional neural network(CSPDarknet53)was combined with a transformer to construct a new hybrid model,HCSP-Net.This hybrid model was employed to tri-classify color fundus photography into the normal macula(NM),dry macular degeneration(DMD),and wet macular degeneration(WMD)based on clinical classification manifestations,thus identifying and resolving AMD as early as possible with color fundus photography.To further enhance the performance of this model,grouped convolution was introduced in this study without significantly increasing the number of parameters.HCSP-Net was validated using an independent test set.The average precision of HCSPNet in the diagnosis of AMD was 99.2%,the recall rate was 98.2%,the F1-Score was 98.7%,the PPV(positive predictive value)was 99.2%,and the NPV(negative predictive value)was 99.6%.Moreover,a knowledge distillation approach was also adopted to develop a lightweight student network(SCSP-Net).The experimental results revealed a noteworthy enhancement in the accuracy of SCSP-Net,rising from 94%to 97%,while remarkably reducing the parameter count to a quarter of HCSP-Net.This attribute positions SCSP-Net as a highly suitable candidate for the deployment of resource-constrained devices,which may provide ophthalmologists with an efficient tool for diagnosing AMD.

Regulatory factors of Nrf2 in age-related macular degeneration pathogenesis

Age-related macular degeneration(AMD)is a complicated disease that causes irreversible visual impairment.Increasing evidences pointed retinal pigment epithelia(RPE)cells as the decisive cell involved in the progress of AMD,and the function of anti-oxidant capacity of PRE plays a fundamental physiological role.Nuclear factor erythroid 2 related factor 2(Nrf2)is a significant transcription factor in the cellular anti-oxidant system as it regulates the expression of multiple anti-oxidative genes.Its functions of protecting RPE cells against oxidative stress(OS)and ensuing physiological changes,including inflammation,mitochondrial damage and autophagy dysregulation,have already been elucidated.Understanding the roles of upstream regulators of Nrf2 could provide further insight to the OS-mediated AMD pathogenesis.For the first time,this review summarized the reported upstream regulators of Nrf2 in AMD pathogenesis,including proteins and miRNAs,and their underlying molecular mechanisms,which may help to find potential targets via regulating the Nrf2 pathway in the future research and further discuss the existing Nrf2 regulators proved to be beneficial in preventing AMD.

Subretinal fibrosis secondary to neovascular age-related macular degeneration:mechanisms and potential therapeutic targets

Subretinal fibrosis is the end-stage sequelae of neovascular age-related macular degeneration.It causes local damage to photoreceptors,retinal pigment epithelium,and choroidal vessels,which leads to permanent central vision loss of patients with neovascular age-related macular degeneration.The pathogenesis of subretinal fibrosis is complex,and the underlying mechanisms are largely unknown.Therefore,there are no effective treatment options.A thorough understanding of the pathogenesis of subretinal fibrosis and its related mechanisms is important to elucidate its complications and explore potential treatments.The current article reviews several aspects of subretinal fibrosis,including the current understanding on the relationship between neovascular age-related macular degeneration and subretinal fibrosis;multimodal imaging techniques for subretinal fibrosis;animal models for studying subretinal fibrosis;cellular and non-cellular constituents of subretinal fibrosis;pathophysiological mechanisms involved in subretinal fibrosis,such as aging,infiltration of macrophages,different sources of mesenchymal transition to myofibroblast,and activation of complement system and immune cells;and several key molecules and signaling pathways participating in the pathogenesis of subretinal fibrosis,such as vascular endothelial growth factor,connective tissue growth factor,fibroblast growth factor 2,platelet-derived growth factor and platelet-derived growth factor receptor-β,transforming growth factor-βsignaling pathway,Wnt signaling pathway,and the axis of heat shock protein 70-Toll-like receptors 2/4-interleukin-10.This review will improve the understanding of the pathogenesis of subretinal fibrosis,allow the discovery of molecular targets,and explore potential treatments for the management of subretinal fibrosis.

Influence of CFH,HTRA1 and ARMS2 polymorphisms in the response to intravitreal ranibizumab treatment for wet age-related macular degeneration in a Spanish population

AIM：To determine whether gene polymorphisms of the major genetic risk loci for age-related macular degeneration（AMD）：ARMS2（rs10490923）,the complement factor H（CFH）（rs1410996） and HTRA1（rs11200638） influence the response to a treatment regimen with ranibizumab for exudative AMD.METHODS：This study included 100 patients（100 eyes）with exudative AMD.Patients underwent a treatment with ranibizumab injections monthly during three months.Reinjections were made when the best corrected visual acuity（BCVA） decrease five letters（ETDRS） or central subfield retinal thickness gained 100 pm in optical coherence tomography image.Genotypes（rs10490923,rs1410996 and rs11200638） were analyzed using TaqMan probes or polymerase chain reaction-restricted fragment length polymorphisms analysis.RESULTS：There were no statistically significant differences in allelic distribution of CFH（rs1410996）,ARMS2（rs10490923） and HTRA1（rs11200638）polymorphisms regarding to response to ranibizumab treatment.CONCLUSION：Ranibizumab treatment response is not related to CFH（rs1410996）,ARMS2（rs10490923） and HTRA1（rs11200638） poymorphisms.

Temporal pattern of resolution/recurrence of choroidal neovascularization during bevacizumab therapy for wet age-related macular degeneration

AIMTo characterize temporal pattern of resolution and recurrence of naive choroidal neovascularization (CNV) secondary to wet age-related macular degeneration (AMD) treated with intravitreal bevacizumab on as needed regimen, and to analyze baseline risk factors for CNV resolution or recurrence.

Recent Developments in the Treatment of Wet Age-related Macular Degeneration

Age-related macular degeneration(AMD)is the most common cause of irreversible blindness and visual impairment in individuals over the age of 50 years in western societies.More than 25 million people currently suffer from this illness in the world,with an additional 500000 every year,approximately.It is a multifactorial ocular disease that affects the maculae due to a late-onset progressive neurodegeneration and dysfunction of photoreceptors and retinal pigment epithelium(RPE).There are many subtypes of AMD but basically two broad forms:the nonneovascular(dry,nonexudative)and neovascular(wet,exudative).Exudative AMD is the less common form(about 15%)but tends to progress more rapidly.At the moment,wet AMD is treated primarily on the basis of anti-vascular endothelial growth factor(VEGF)agents,which have led to massive improvement in the prognosis of the disease since they were first introduced.This article focuses on the latest treatment approaches to neovascular AMD.An extensive literature review was performed in order to illustrate the effectiveness of current and future anti-VEGF agents as well as the landmark clinical studies that have been carried out to establish these drugs as a gold standard in the therapy of wet AMD.

Observation on the quality of life before and after the injection of antiangiogenic drug in the vitreous cavity of patients with wet age-related macular degeneration

Objective: To explore the vision-related quality of life ( VRQL) before and after the injection of antiangiogenic drug into the vitreous cavity of patients with wet age-related macular degeneration ( AMD) . Methods: The 2000 edition of the Visual Functioning Questionnaire 25 that was issued by the Na-tional Eye Institute was applied, and the VRQL evaluation was conducted on the initially diagnosed patients with wet-AMD before and after the injection of ranibizumab into the vitreous cavity. Results: Among the wet-AMD patients, patients with better distance visual acuity before the in-travitreal injection had a lower VFQ-25 score. After the vitreous cavity injection, the VFQ-25 questionnaire score was related to patient care and education from the doctors and nurses; specific-ally, the better the nursing, the higher the score. Conclusions: Before the vitreous cavity injection, the degree of distance visual acuity is an im-portant factor affecting the VRQL of wet-AMD patients. In addition, patient care and education from the doctors and nurses toward patients during the pre-, intra-and post-operation of the intrav-itreal injection are also important factors affecting the VRQL.

Health resource utilization and the economic burden of patients with wet age-related macular degeneration in Thailand

AIM: To determine healthcare resource utilization and the economic burden associated with wet age-related macular degeneration(AMD) in Thailand ·METHODS: This study included patients diagnosed with wet AMD that were 60 years old or older,and had best corrected visual acuity(BCVA) measured at least two times during the follow-up period. We excluded patients having other eye diseases. Two separate sub-studies were conducted. The first sub-study was a retrospective cohort study; electronic medical charts were reviewed to estimate the direct medical costs. The second sub-study was a cross-sectional survey estimating the direct non-medical costs based on face-to-face interviews using a structured questionnaire. For the first sub-study,direct medical costs,including the cost of drugs,laboratory,procedures,and other treatments were obtained. For the second sub-study,direct non-medical costs,e.g. transportation,food,accessories,home renovation,and caregiver costs,were obtained from face-to-face interviews with patients and/ or caregivers. ·RESULTS: For the first sub-study,sixty-four medical records were reviewed. The annual average number of medical visits was 11.1 ±6.0. The average direct medical costs were $3 604 ±4 530 per year. No statistically-significant differences of the average direct medical costs among the BCVA groups were detected(P =0.98). Drug costs accounted for 77% of total direct medical costs. For direct non-medical costs,67 patients were included. Forty-eight patients(71.6%) required the accompaniment of a person during the out-patient visit. Seventeen patients(25.4%) required a caregiver at home. The average direct non-medical cost was $2 927 ±6 560 per year. There were no statistically-significant differences in the average costs among the BCVA groups(P =0.74). Care-giver cost accounted for 87% of direct non-medical costs.·CONCLUSION: Our study indicates that wet AMD is associated with a substantial economic burden,especially concerning drug and care-giver costs.

Matrix γ-carboxyglutamate protein and Fetuin-A, in wet type age-related macular degeneration

AIM: To evaluate the high sensitivity C-reactive protein(hs CRP), Fetuin-A and matrix γ-carboxyglutamate protein(MGP) as the main factors for vascular calcification and inflammation in serum of patients with advanced age-related macular degeneration(ARMD) in comparison to healthy controls. METHODS: The subjects were 40 patients with choroidal neovascularization(CNV) having a mean age of70.9 ±9.1y and a matched group of 49 apparently healthy control subjects. The ARMD was diagnosed using a slitlamp with superfield lens, fundus photography and fluorescein angiography. Measurement of hs CRP was done by nephelometry method. Levels of Fetuin-A and MGP were measured by enzyme-linked immunosorbent assay(ELISA) technique.RESULTS: hs CRP [0.45(0.07-2.63) mg/L vs 0.25(0.03-1.2) mg/L, P =0.02)] and Fetuin-A levels(50.27 ±5.04 vs44.99±10.28 ng/m L, P =0.009) were higher in the patients than in the control groups. We could not find significant difference in MGP level between two groups(P =0.08).There was not a significant correlation between MGP with Fetuin-A and hs CRP among the patients(P =0.7, P =0.9respectively). A significant negative correlation of hs CRP with Fetuin-A was observed in both case and control groups(P =0.004, r =-0.33 and P =0.001, r =-0.54,respectively).CONCLUSION: Although our study shows that serum hs CRP and Fetuin-A is increased in CNV patients as well as negatively correlated with both study groups, their direct role on pathogenesis of ARMD required future studies.

Therapeutic effect of Ranibizumab combined with Triamcinolone Acetonide on wet age-related macular degeneration and its effect on interleukin

Objective:To observe the clinical efficacy of ranibizumab combined with triamcinolone acetonide on wet age-related macular degeneration(AMD)and explore the effect of this method on the levels of IL-1β,IL-2,IL-6 and IL-8.Methods:Prospective study was conducted in this research.86 cases of patients with wet AMD(102 eyes)admitted in Baogang Hospital of Inner Mongolia from November 2017 to October 2018 were chosen and randomly divided into the ranibizumab group(43 cases,50 eyes)and the combination group(43 cases,52 eyes).The ranibizumab group of patients were given intravitreal injection of ranibizumab,and the combination group was additionally given triamcinolone acetonide on the basis of the ranibizumab group.The intraocular pressure values of the two groups before treatment,in 2 weeks,1 month and 3 months after treatment were compared.The central macular thickness(CMT)and visual acuity of the two groups before treatment as well as in 1 month,3 months and 6 months after treatment were compared.The levels of IL-1β,IL-2,IL-6 and IL-8 in the serum were compared between the two groups before treatment and in 1 month after treatment.The incidences of complications during treatment in the two groups were recorded and compared.The data were analyzed by use of t-test,repeated measures ANOVA andχ^(2) test.Results:There were no statistically significant differences in intraocular pressure value between the two groups(Fgroups=1.275,p=.496;Ftime=1.810,p=.211;Finteraction=1.772,p=.335).There were no statistically significant differences in CMT and visual acuity before treatment between the two groups(t=0.042,p=.967;t=0.720,p=.473).In one month,three months and six months after treatment,CMT in the combined group was lower than that in the ranibizumab group(t=2.086,p=.039;t=3.398,p=.001;t=2.987,p=.004),and the visual acuity of the combined group was higher than that of the ranibizumab group(t=3.265,p=.001;t=2.217,p=.029;t=2.519,p=.013).CMT showed a decreasing tendency(tbefore treatment vs.t1 month after treatment=6.210,4.218,p<.001;t1 month after treatment vs.t3months after treatment=16.772,15.865,p<.001;t3 months after treatment vs.t6 months after treatment=4.472,4.848,p<.001)and the visual acuity showed an increasing trend(tbefore treatment vs.t1 month after treatment=4.527,8.395,p<.001;t1 month after treatment vs.t3 months after treatment=5.369,5.349,p<.001;t3 months after treatment vs.t6 months after treatment=3.335,3.730,p<.001)with the time going by in the two groups.Compared with the indicators before treatment,the levels of IL-1β,IL-6 and IL-8 in the serum in 1 month after treatment were lower in both two groups(tcombination group=10.544,32.169,33.156,all p<.001;tranibizumab group=8.996,25.687,30.754,all p<.001),and these indicators in the combination group were lower than those in the ranibizumab group(t=2.894,p=.005;t=5.997,p<.001;t=3.934,p<.001).Compared with the indicators before treatment,the levels of IL-2 in the serum in 3 months after treatment in the two groups were higher(t=20.067,9.091,all p<.001),and the indicator in the combination group was higher than that in the ranibizumab group(t=7.705,p<.001).There were no statistically significant differences in the incidences of bleeding,intraocular foreign body sensation and transient high IOP and the total incidence of complications between the two groups(correctionχ^(2)=0.001,p=.972;correctionχ^(2)=0.221,p=.638;Fisher’s exact test p=.116;correctionχ^(2)=0.004,p=.951).Conclusions:Intravitreal injection of ranibizumab combined with triamcinolone acetonide can effectively improve the visual function of wet AMD,reduce CMT and the levels of IL-1β,IL-6 and IL-8 in the serum,increase the level of IL-2 in the serum and relieve the degree of inflammatory responses.

Mechanism of Mingjing Granules in Treating Wet Age-Related Macular Degeneration Based on Network Pharmacology and Experimental Verification

Objective:To analyze the potential mechanism of Mingjing granules in the treatment of wet age-related macular degeneration(wAMD)based on the research methods of network pharmacology and molecular docking approach and to provide a new reference for the currently limited treatment of wAMD.Materials and Methods:We searched TCMSP,GeneCards,OMIM,PharmGkb,TTD,and DrugBank database to screen the main active ingredients of Mingjing granules and their therapeutic targets of wAMD.The network of active components and targets was constructed using Cytoscape3.6.1 software,which was also used for the topological analysis of target genes.The network of Protein-Protein Interactions(PPI)was mapped using the String platform.We also used R language to do the Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway for additional analysis.Molecular docking studies were finished by Chemoffice,Autodock,and Pymol.Finally,the efficacy of the Mingjing granules was examined in animal experiments,in which we used enzyme-linked immunosorbent assay to the contents of vascular endothelial growth factor(VEGF)and matrix metalloproteinase-9(MMP-9)levels in peripheral blood.Results:Active compounds,including quercetin,lignocaine,and kaempferol,were found.PPI network analysis showed that tumor necrosis factor(TNF),MMP-9,epidermal growth factor(EGF),prostaglandin-endoperoxide synthase 2(PTGS2),and caspase-3(CASP3)were related to both Mingjing granules and wAMD.GO and KEGG pathway analysis showed that these targets were mainly involving lipids and atherosclerosis,TNF,and interleukin-17(IL-17)signaling pathways.Docking studies suggested that quercetin and luteolin can fit in the binding pocket of four target proteins(CASP3,EGF,PTGS2,and TNF).In the vivo experiment,the Mingjing granules were found to be effective on the expression of VEGF and MMP-9 in peripheral blood.Conclusions:This study initially reveals the multi-constituent,multi-target,and multi-pathway mechanism of action of Mingjing granules in the treatment of wAMD and implies the inhibition of choroidal neovascularization may be related to the expression of VEGF and MMP-9.

Oxidative stress in retinal pigment epithelium degeneration:from pathogenesis to therapeutic targets in dry age-related macular degeneration

Age-related macular degeneration is a primary cause of blindness in the older adult population. Past decades of research in the pathophysiology of the disease have resulted in breakthroughs in the form of anti-vascular endothelial growth factor therapies against neovascular age-related macular degeneration;however, effective treatment is not yet available for geographical atrophy in dry agerelated macular degeneration or for preventing the progression from early or mid to the late stage of age-related macular degeneration. Both clinical and experimental investigations involving human agerelated macular degeneration retinas and animal models point towards the atrophic alterations in retinal pigment epithelium as a key feature in age-related macular degeneration progression. Retinal pigment epithelium cells are primarily responsible for cellular-structural maintenance and nutrition supply to keep photoreceptors healthy and functional. The retinal pigment epithelium constantly endures a highly oxidative environment that is balanced with a cascade of antioxidant enzyme systems regulated by nuclear factor erythroid-2-related factor 2 as a main redox sensing transcription factor. Aging and accumulated oxidative stress triggers retinal pigment epithelium dysfunction and eventually death. Exposure to both environmental and genetic factors aggravates oxidative stress damage in aging retinal pigment epithelium and accelerates retinal pigment epithelium degeneration in age-related macular degeneration pathophysiology. The present review summarizes the role of oxidative stress in retinal pigment epithelium degeneration, with potential impacts from both genetic and environmental factors in age-related macular degeneration development and progression. Potential strategies to counter retinal pigment epithelium damage and protect the retinal pigment epithelium through enhancing its antioxidant capacity are also discussed, focusing on existing antioxidant nutritional supplementation, and exploring nuclear factor erythroid-2-related factor 2 and its regulators including REV-ERBα as therapeutic targets to protect against age-related macular degeneration development and progression.

Volumetric fluid analysis of fixed monthly anti-VEGF treatment in patients with neovascular age-related macular degeneration

·AIM:To evaluate visual outcomes and changes in fluid after administering monthly anti-vascular endothelial growth factor(VEGF)injections to treat neovascular agerelated macular degeneration(n AMD)with subretinal fluid(SRF)and pigment epithelial detachment(PED).·METHODS:This prospective study included eyes with n AMD previously treated with as-needed anti-VEGF injections.The patients were treated with six monthly intravitreal injections of ranibizumab.Quantitative volumetric segmentation analyses of the SRF and PED were performed.The main outcome measures included best-corrected visual acuity(BCVA),and SRF and PED volumes.·RESULTS:Twenty eyes of 20 patients were included in this study.At the 6-month follow-up,BCVA and PED volume did not change significantly(P=0.110 and 0.999,respectively)but the mean SRF volume decreased from 0.53±0.82 mm3 at baseline to 0.08±0.23 mm3(P=0.002).The absorption rate of the SRF volume was negatively correlated with the duration of previous antiVEGF treatment(P=0.029).Seven of the 20 eyes(35%)showed a fluid-free macula and significant improvement in BCVA(P=0.036)by month 6.·CONCLUSION:Quantifying the SRF can precisely determine the patient’s responsiveness to anti-VEGF treatment of n AMD.

Extracellular vesicles as a potential therapeutic for age-related macular degeneration

Age-related macular degeneration is a major global cause of central visual impairment and seve re vision loss.With an aging population,the already immense economic burden of costly anti-vascular endothelial growth fa ctor treatment is likely to increase.In addition,current conventional treatment is only available for the late neovascular stage of age-related macular degeneration,and injections can come with potentially devastating complications,introducing the need for more economical and ris kfree treatment.In recent years,exosomes,which are nano-sized extracellular vesicles of an endocytic origin,have shown immense potential as diagnostic biomarkers and in the therapeutic application,as they are bestowed with characte ristics including an expansive cargo that closely resembles their parent cell and exceptional ability of intercellular communication and targeting neighboring cells.Exosomes are currently undergoing clinical trials for various conditions such as type 1 diabetes and autoimmune diseases;however,exosomes as a potential therapy for seve ral retinal diseases have just begun to undergo scrutinizing investigation with little literature on age-related macular degeneration specifically.This article will focus on the limited literature availa ble on exosome transplantation treatment in age-related macular degeneration animal models and in vitro cell cultures,as well as briefly identify future research directions.Current literature on exosome therapy using agerelated macular degeneration rodent models includes laser retinal injury,N-methyl-N-nitrosourea,and royal college of surgeon models,which mimic inflammatory and degenerative aspects of agerelated macular degeneration.These have shown promising results in preserving retinal function and morphology,as well as protecting photoreceptors from apoptosis.Exosomes from their respective cellular origins may also act by regulating the expression of various inflammatory cyto kines,mRNAs,and proteins involved in photo receptor degeneration pathways to exert a therapeutic effect.Various findings have also opened exciting prospects for the involvement of cargo components in remedial effects on the damaged macula or retina.

Development of Knowledge,Attitude and Practice Questionnaire for age-related macular degeneration patients

AIM:To develop and validate a questionnaire to evaluate knowledge,attitude and practice of patients diagnosed with age-related macular degeneration(AMD)who have undergone intravitreal injection treatment.METHODS:This study was conducted among patients diagnosed with AMD in Kuala Lumpur.The generation of the instrument included four phases which included item and domains development,content,face validity and exploratory factor analysis.Content validity and modified Kappa was used for validation of knowledge domain.Exploratory factor analysis was used for validation of both attitude and practice domains.Face validity was conducted in 12 patients,content validity was ascertained in 120 patients and test-retest reliability was determined in 39 patients with AMD.RESULTS:Content validity index(CVI)and modified kappa showed excellent values for most items in the knowledge domain with CVI for item(I-CVI)values between 0.78-1.0 and Kappa values of>0.74.The Kaiser-MeyerOlkin(KMO)sampling adequacy showed acceptable scores of 0.70 and 0.75 for both attitude and practice domains respectively and Bartlett’s Test of sphericity were significant(χ^(2)=0.00,P<0.001).Factor analysis resulted in five factors with thirty items for attitude domain and four factors with twenty items for practice domain.The Cronbach’s alpha showed acceptable values for all items in knowledge,attitude and practice domain with values>0.70 and good test-retest reliability.The final version of the questionnaire consisted of 93 items from four sections consisting of demographic details,knowledge,attitude and practice.CONCLUSION:The findings of this validation and reliability study show that the developed questionnaire has a satisfactory psychometric property for measuring KAP of patients diagnosed with AMD undergoing intravitreal injection treatment.

Circular RNA expression and the competitive endogenous RNA network in pathological,age-related macular degeneration events:A cross-platform normalization study

Age-related macular degeneration(AMD)causes irreversible blindness in people aged over 50 worldwide.The dysfunction of the retinal pigment epithelium is the primary cause of atrophic AMD.In the current study,we used the ComBat and Training Distribution Matching method to integrate data obtained from the Gene Expression Omnibus database.We analyzed the integrated sequencing data by the Gene Set Enrichment Analysis.Peroxisome and tumor necrosis factor-α(TNF-α)signaling and nuclear factor kappa B(NF-κB)were among the top 10 pathways,and thus we selected them to construct AMD cell models to identify differentially expressed circular RNAs(circRNAs).We then constructed a competing endogenous RNA network,which is related to differentially expressed circRNAs.This network included seven circRNAs,15 microRNAs,and 82 mRNAs.The Kyoto Encyclopedia of Genes and Genomes analysis of mRNAs in this network showed that the hypoxia-inducible factor-1(HIF-1)signaling pathway was a common downstream event.The results of the current study may provide insights into the pathological processes of atrophic AMD.

Gene Therapy Activates Retinal Pigment Epithelium Cell Proliferation for Age-related Macular Degeneration in a Mouse Model

Objective Age-related macular degeneration(AMD)is a degenerative retinal disease.The degeneration or death of retinal pigment epithelium(RPE)cells is implicated in the pathogenesis of AMD.This study aimed to activate the proliferation of RPE cells in vivo by using an adeno-associated virus(AAV)vector encodingβ-catenin to treat AMD in a mouse model.Methods Mice were intravitreally injected with AAV2/8-Y733F-VMD2-β-catenin for 2 or 4 weeks,andβ-catenin expression was measured using immunofluorescence staining,real-time quantitative reverse transcription polymerase chain reaction(PCR),and Western blotting.The function ofβ-catenin was determined using retinal flat mounts and laser-induced damage models.Finally,the safety of AAV2/8-Y733F-VMD2-β-catenin was evaluated by multiple intravitreal injections.Results AAV2/8-Y733F-VMD2-β-catenin induced the expression ofβ-catenin in RPE cells.It activated the proliferation of RPE cells and increased cyclin D1 expression.It was beneficial to the recovery of laser-induced damage by activating the proliferation of RPE cells.Furthermore,it could induce apoptosis of RPE cells by increasing the expression of Trp53,Bax and caspase3 while decreasing the expression of Bcl-2.Conclusion AAV2/8-Y733F-VMD2-β-catenin increasedβ-catenin expression in RPE cells,activated RPE cell proliferation,and helped mice heal from laser-induced eye injury.Furthermore,it could induce the apoptosis of RPE cells.Therefore,it may be a safe approach for AMD treatment.