Investigating the causal link between gut microbiota and dry age-related macular degeneration:a bidirectional Mendelian randomization study

AIM:To assess the causal link between 211 gut microbiota(GM)taxa and dry age-related macular degeneration(dAMD)risk.METHODS:Mendelian randomization using instrumental factors taken from a genome-wide association study(GWAS)were used.Inverse variance weighted(IVW)analysis and sensitivity analysis were performed on the FinnGen project,which included 5095 cases and 222590 controls.RESULTS:The IVW analysis showed substantial genusand family-level relationships between GM taxa and dAMD risk.Specifically,the family Peptococcaceae(P=0.03),genus Bilophila(P=3.91×10^(-3)),genus Faecalibacterium(P=6.55×10^(-3)),and genus Roseburia(P=0.04)were linked to a higher risk of developing dAMD,while the genus Candidatus Soleaferrea(P=7.75×10^(-4)),genus Desulfovibrio(P=0.04)and genus Eubacterium ventriosum group(P=0.04)exhibited a protective effect against dAMD.No significant causal relationships were observed at higher taxonomic levels.Additionally,in the reverse IVW analysis,no meaningful causal effects of the 7 GM taxa.CONCLUSION:These findings give support for the gutretina axis participation in dAMD and shed light on putative underlying processes.Investigations on the connection between GM and dAMD have not yet revealed the underlying mechanism.

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.

Low-fluence photodynamic therapy combinations in the treatment of exudative age-related macular degeneration

AIM:To compare the efficacy of low-fluence photodynamic therapy(PDT) combinations in the treatment of age-related macular degeneration(AMD).· METHODS:Forty-five previously untreated eyes of 45 patients with exudative AMD whose best-corrected visual acuity(BCVA) was ≥0.3(Snellen) were enrolled.15 patients in Group I underwent low-fluence PDT(25J/cm2-300mW/cm2-83sec) and intravitreal pegaptanib combination,15 patients in Group II underwent PDT(50J/cm2-600mW/cm2-83sec) and intravitreal pegaptanib combination while,15 patients in Group III underwent intravitreal pegaptanib monotherapy.Complete ophthalmologic examinations were performed in pre and post treatment visits,and the results were statistically analised.A clinical activity score(CAS) was calculated by using changes in lesion size,amount of hemorrhage,staining pattern in FA and OCT measurement of intra/subretinal fluid.≤3 logMAR lines of decrease in BCVA and decrease in CAS were considered as successful treatment.· RESULTS:The mean age of 19 female(42.2%) and 26 male(57.8%) patients was(72.82±8.02) years.Mean follow-up was(13.93±5.87) months.Lesion type was occult in 28 eyes(62.2%).Treatment success rates according to BCVA assessments were 86.7%,80%,60% and mean BCVA decrease were 0.3,1.0,2.2 logMAR lines in Group I,II and III,respectively(P >0.05).According to the changes in central macular thickness and CAS,no difference was found among the study groups(P =0.850 and P =0.811,respectively).Patients treated with combination regimens had lower intravitreal injection frequencies(P =0.015).· CONCLUSION:Combination regimen with intravitreal pegaptanib and low-fluence PDT seems to be safe and effective in stabilizing the clinical activity and BCVA in exudative AMD.·

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.

RNA-sequencing expression profile and functional analysis of retinal pigment epithelium in atrophic age-related macular degeneration

The retinal pigment epithelium(RPE)is fundamental to sustaining retinal homeostasis.RPE abnormality leads to visual defects and blindness,including age-related macular degeneration(AMD).Although breakthroughs have been made in the treatment of neovascular AMD,effective intervention for atrophic AMD is largely absent.The adequate knowledge of RPE pathology is hindered by a lack of the patients'RPE datasets,especially at the single-cell resolution.In the current study,we delved into a large-scale single-cell resource of AMD donors,in which RPE cells were occupied in a substantial proportion.Bulk RNA-seq datasets of atrophic AMD were integrated to extract molecular characteristics of RPE in the pathogenesis of atrophic AMD.Both in vivo and in vitro models revealed that carboxypeptidase X,M14 family member 2(CPXM2),was specifically expressed in the RPE cells of atrophic AMD,which might be induced by oxidative stress and involved in the epithelial-mesenchymal transition of RPE cells.Additionally,silencing of CPXM2 inhibited the mesenchymal phenotype of RPE cells in an oxidative stress cell model.Thus,our results demonstrated that CPXM2 played a crucial role in regulating atrophic AMD and might serve as a potential therapeutic target for atrophic AMD.

AB023.Characterization of a novel anti-angiogenic protein for the treatment of exudative age-related macular degeneration

Background:Age-related macular degeneration(AMD)is a leading cause of blindness in Canada.The exudative(wet)form of AMD accounts for approximately 15%of AMD patients,but is responsible for the majority of severe vision loss associated with the disease.Wet AMD is characterized by choroidal neovascularization,the abnormal growth of blood vessels from the choroid into the sub-retinal space.Current therapies for exudative AMD directly target and inhibit the vascular endothelial growth factor(VEGF)signaling pathway,a signaling axis that promotes endothelial cell survival.While initially effective at restoring visual acuity,recent studies suggest that chronic use of anti-VEGF therapies can lead to further vision impairment through off-target effects on photoreceptors and other non-vascular tissues.These off-target effects of anti-VEGF therapy highlights the need for alternative treatments for this increasingly common disease.We have recently identified a novel anti-angiogenic protein,AAP1 that inhibits retinal angiogenesis during development.As a regulator of the vasculature,our current work aims to characterize the function of AAP1 in endothelial cells and determine the potential of AAP1 as a therapy for exudative AMD.Methods:To address our aims,we used various in vivo and in vitro models of normal and pathological vascular growth.Mice were injected intravitreally with AAP1 to investigate its effects on developmental and pathological angiogenesis.Using HUVECs,we employed immunofluorescent quantifications to determine the impact of AAP1 on sprouting angiogenesis by measuring cellular proliferation,apoptosis and migration.To investigate the signaling events that mediate the actions of AAP1,we examined key signaling pathways involved in angiogenesis by western blotting and qPCR.Results:We evaluated the role of AAP1 as a regulator of angiogenesis during retinal development and mouse models of AMD.Our pilot data show that AAP1 prevents angiogenesis in vitro and in vivo,and that it can also inhibit pathological neovascularization in experimental models of AMD.In spite of its anti-angiogenic effects,our data show that AAP1 does not adversely affect photoreceptors.Both in vitro and in vivo systems showed a decrease in cellular division,while apoptosis was not affected in response to AAP1 treatment.While cellular migration was reduced in AAP1-treated HUVECs,cellular polarity was not affected.Finally,gene and protein expression of key angiogenic factors were modified in response to AAP1.Conclusions:AAP1 is a potent regulator of angiogenesis.However,in contrast to anti-VEGF agents,our data suggests that AAP1 does not adversely affect the photoreceptors-highlighting the therapeutic potential of this protein.Further data generated from our studies characterizing the mechanism of AAP1 action may lead to a novel treatment option for AMD patients preventing vision loss and improving their quality of life.

Increased serum levels of soluble CD146 and vascular endothelial growth factor receptor 2 in patients with exudative age-related macular degeneration

AIM: To investigate serum levels of soluble CD146(s CD146) and vascular endothelial growth factor receptor 2(VEGFR2) in patients with age-related macular degeneration(AMD). METHODS: Eighty-eight patients with exudative AMD and 45 sex-and age-matched healthy controls were enrolled in this study conducted in China. Serum samples was obtained from the patients with exudative AMD and from the controls. Serum sCD146 and VEGFR2 protein levels were measured using an enzyme-linked immunosorbent assay.RESULTS: We found that serum sCD146 and VEGFR2 protein levels were significantly higher in the patients with exudative AMD group than in the controls(t=3.859, P<0.001 and t=3.829, P<0.001, respectively). Serum sCD146 levels were significantly higher in patients with classic choroidal neovascularization(CNV) than in those with occult CNV(t=9.899, P<0.001). There was a significant difference in the trend for exudative AMD in the highest versus lowest quartile of circulating sCD146 levels(χ2=10.29, P=0.001). The receiver operating characteristic curve analysis showed that the area under the curve was 0.696 for s CD146(95%CI: 0.601-0.791) with an optimum diagnostic cut-off value of 157.16 ng/mL, a sensitivity of 55.7%, and a specificity of 82.2%.CONCLUSION: The serum sCD146 level increases and may be a biomarker for exudative AMD.

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.

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.

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.

Retinal pigment epithelium–Bruch’s membrane volume in grading of age-related macular degeneration

AIM:To assess the agreement of optical coherence tomography(OCT)algorithm-based retinal pigment epithelium–Bruch’s membrane complex volume(RBV)with fundus photograph-based age-related macular degeneration(AMD)grading.METHODS:Digital color fundus photographs(CFPs)and spectral domain OCT images were acquired from 96 elderly subjects.CFPs were graded according to Age-Related Eye Disease Study(AREDS)classification.OCT image segmentation and RBV data calculation were done with OrionTM software.Univariate and multivariate analyses were performed to find out whether AMD lesion features associated with higher RBVs.RESULTS:RBV correlated with AMD grading(rs=0.338,P=0.001),the correlation was slightly stronger in early AMD(n=52;rs=0.432,P=0.001).RBV was higher in subjects with early AMD compared with those with no AMD lesions evident in fundus photographs(1.05±0.20 vs 0.96±0.13 mm3,P=0.023).In multivariate analysis higher RBVs were associated significantly with higher total drusen(β=0.388,P=0.027)and pigmentation areas(β=0.319,P=0.020)in fundus photographs,whereas depigmentation area(β=-0.295,P=0.015)associated with lower RBV.CONCLUSION:RBV correlate with AMD grading status,with a stronger association in patients with moderate,non-late AMD grades.This effect is driven mostly by lesions with drusen or pigmentation.Lesions with depigmentation tend to have lower values.RBV is more comprehensive measurement of the key area of AMD pathogenesis,compared to sole drusen volume analysis.RBV measurements are independent on grader variations and offer a possibility to quantify early and middle grade AMD lesions in a research setting,but may not substitute fundus photograph-based grading in the whole range of AMD spectrum.

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.

Narrative review of risuteganib for the treatment of dry age-related macular degeneration (AMD)

Age-related macular degeneration(AMD)is a leading cause of blindness worldwide.AMD most commonly affects older individuals and is characterized by irreversible degeneration of the retinal pigment epithelium and neurosensory retina.Currently,there are limited treatment options for dry AMD outside of lifestyle modification and nutrient supplementation.Risuteganib[Luminate(ALG-1001),Allegro Ophthalmics,CA,USA]is an intravitreally administered inhibitor of integrin heterodimersαVβ3,αVβ5,α5β1,andαMβ2.It is currently undergoing clinical trials for the treatment of dry AMD and diabetic macular edema(DME).Preclinical studies have shown that risuteganib has an effect on the pathways for angiogenesis,inflammation,and vascular permeability.Ongoing clinical trials have had promising results showing improvements in patient best corrected visual acuity(BCVA)and reduced central macular thickness measured by optical coherence tomography(OCT).There is a pressing need for treatments for dry AMD and while risuteganib appears to have a potential benefit for patients,more data are needed before one can truly evaluate its efficacy.This narrative review provides a concise summary of the most up to date data regarding the proposed mechanism of action of risuteganib in the treatment of nonexudative AMD and DME as well as the results from recent phase 1 and phase 2 clinical trials.

Progress of clinical therapies for dry age-related macular degeneration

Dry age-related macular degeneration(AMD)is a progressive blinding disease that currently affects millions of people worldwide with no successful treatment available.Significant research efforts are currently underway to develop therapies aimed at slowing the progression of this disease or,more notably,reversing it.Here the therapies which have reached clinical trial for treatment of dry AMD were reviewed.A thorough search of Pub Med,Embase,and Clinicaltrials.gov has led to a comprehensive collection of the most recent strategies being evaluated.This review also endeavors to assess the status and future directions of therapeutics for this debilitating condition.

Quantitative Assessment of Foveal Avascular Zone in Patients with Early and Intermediate Nonexudative Age-Related Macular Degeneration Using Optical Coherence Tomography-Angiography

Optical coherence tomography-angiography (OCT-A) is a relatively new non-invasive imaging technique which provides three-dimensional visualization of the retinal and choroidal microvasculature. Recently, OCT-A is widely used in the diagnosis of age-related macular degeneration (AMD). Purpose: To compare 3 quantitative indexes of foveal avascular zone (FAZ)—area (A), perimeter (Pm), and circularity (C) in patients with early and intermediate nonexudative AMD and healthy subjects using OCT-A. Methods: Eighty-nine patients with nonexudative AMD (n = 89 eyes) were enrolled in the study. They were compared with sex- and age-matched control group of 66 healthy subjects (n = 66 eyes). The patients with nonexudative AMD were divided into 2 subgroups—early AMD (n = 42 eyes) and intermediate AMD (n = 47 eyes). All participants underwent OCT-A (3 × 3 mm scans, Cirrus HD-OCT, Angioplex, Carl Zeiss Meditec, Dublin, CA). Results: There was no statistically significant difference in all 3 assessed indexes between the early AMD subgroup and the control group (A ? P = 0.139;Pm ? P = 0.230;and C ? P = 0.191). There was also no statistically significant difference in all 3 assessed indexes between the intermediate AMD subgroup and the control group (A ? P = 0.106, Pm ? P = 0.124, and C ? P = 0.102, respectively). Conclusions: According to our results from the assessment of FAZ in patients with early and intermediate AMD, we hypothesize that macular perfusion remains fairly unchanged in the nonexudative stages of the disease. OCT-A is a reliable technique for visualizing and quantifying FAZ in patients with nonexudative AMD.

Laser treatment in 341 patients with exudative agerelated macular degeneration

AIM:To document the prognosis of laser treatment in patients with exudative age-related macular degeneration(AMD).· METHODS:Efficacy of the intervention was evaluated using a before-after method.· RESULTS:A total of 392 eyes of 341 patients with exudative AMD were examined.77.6% had choroideal neovascularisation(CNV).Before the use of indocyanine green(ICG) angiography,occult CNV was detected in only 1.8% of the eyes,but after the use of ICG angiography,this increased to 19.5%(P<0.001).Of the 349 eyes which were followed up,visual acuity had remained stable in 68.2% of the eyes.There was a statistically significant relationship between localisation of lesion and visual acuity changes on pre-and post-laser treatment(P<0.001).Also there was a statistically significant relationship between localisation of lesion and recurrence(P<0.05).The recurrence was less in subfoveal lesions than that in juxtafoveal and extrafoveal lesions.· CONCLUSION:ICG angiography is highly important in the treatment of occult CNV.