The responses of choriocapillary endothelial cells(CCE) and retinal capillary endothelial cells(RCE) in culture,in terms of phosphoinositide(PI) breakdown and cellular mitogenesis, to retinal pigment epithelial cell(R...The responses of choriocapillary endothelial cells(CCE) and retinal capillary endothelial cells(RCE) in culture,in terms of phosphoinositide(PI) breakdown and cellular mitogenesis, to retinal pigment epithelial cell(RPE)-conditioned medium and vasoactive agents have been compared. RPE-conditioned medium did not induce PI breakdown in either type of cell. However, it stimulated DNA synthesis in CCE but not in RCE. Bradykinin(BDK) acted as both a fast signaling and a slow mitogenic factor on CCE, but BDK did not affect PI turnover or DNA synthesis in RCE. In contrast, thrombin stimulated PI turnover in RCE but not in CCE, though it did not induce 3H-thymidine incorporation into either type of cell. These differences in cellular functions between CCE and RCE following stimulation suggest that induction of DNA synthesis and receptor-mediated PI turnover by external factors is determined, at least in part, by the origin of the capillary endothelial cell. Therefore, extrapolation to CCE pathophysiology from experiments using endothelial cells from other capillary origins may not be valid.展开更多
AIMTo report the appearance of choriocapillaris atrophy after combined high dose intravitreal triamcinolone acetonide (TA) and photodynamic therapy (PDT) to treat choroidal neovascularization (CNV) associated with age...AIMTo report the appearance of choriocapillaris atrophy after combined high dose intravitreal triamcinolone acetonide (TA) and photodynamic therapy (PDT) to treat choroidal neovascularization (CNV) associated with age related macular degeneration (AMD).展开更多
A simple mathematical model for the exudative retinal detachment has been developed. The model takes into consideration a typical retinal blister with unknown shape and the fluid flow caused by its accumulation in the...A simple mathematical model for the exudative retinal detachment has been developed. The model takes into consideration a typical retinal blister with unknown shape and the fluid flow caused by its accumulation in the subretinal space through the fluid-leakage into the subretinal space from the choriocapillar is across the outer blood-retina barrier described by Darcy’s law. The theory of bending beams is applied to model the deformation of the retinal blister. The boundary value problem describing the retinal deformation in dimensionless form is solved using the perturbation method. The computational results for the retinal deformation are presented through graphs to illustrate the sensitivity of the deformation to the elastic modulus, the moment of inertia and intraocular pressure and discussed.展开更多
Background: Information on the long-term perfusion status of patients after successful surgery for giant retinal tear (GRT) macula-off rhegmatogenous retinal detachment (RRD) is limited. Purpose: To examine long-term ...Background: Information on the long-term perfusion status of patients after successful surgery for giant retinal tear (GRT) macula-off rhegmatogenous retinal detachment (RRD) is limited. Purpose: To examine long-term structural, functional, and perfusion outcomes in normal control eyes and eyes treated for different degrees of GRT-associated extensions of RRD. Methods: One emmetropic normal eye (control), one healthy highly myopic eye (control myopic), and three eyes surgically treated for GRT (surgical), were included in the study for a long-term comparison of study outcomes. The surgical eyes were classified based on the degree of GRT-associated RRD extension as follows: one eye with GRT-associated RRD extension ˚one eye with GRT-associated RRD extension between 180˚- 270˚and one eye with GRT-associated RRD extension > 270˚. Structural, functional, and perfusion outcomes were compared with those of the control eyes. Results: All three eyes were phakic and the condition was monocular. The mean age of the patients was 48.67 ± 8.50 years (range, 39 - 55 years). All three eyes had GRT macula-off RRD. The mean preoperative time for GRT surgery was 1.2 weeks. The mean pre- and postoperative best corrected visual acuities (BCVA) were 1.87 logMAR and 0.46 logMAR, respectively. The mean postoperative follow-up period was 19.67 ± 5.69 months. Proliferative vitreoretinopathy resulted in multiple surgeries in one eye (31.5%). Long-term postoperative optical coherence tomography (OCT) showed abnormal retinal thickness, ellipsoid zone disruption, and external limiting membrane line discontinuities in one eye. OCT angiography yielded abnormal perfusion indices in the surgically treated eyes. Conclusions: Our data showed multiple structural alterations in spectral-domain OCT biomarkers. One eye that developed secondary epiretinal membrane (ERM) proliferation showed a significantly improved BCVA after proliferation and internal limiting membrane were removed. Perfusion findings were correlated with the final BCVA. Despite a fully reattached retina without ERM proliferation, GRT-associated RRD has a guarded functional prognosis.展开更多
Background: Pathological myopia can be complicated by the presence of posterior staphyloma, macular atrophy, ruptures in Bruch’s membrane, pathologic choroidal neovascularization, and different degrees of myopic trac...Background: Pathological myopia can be complicated by the presence of posterior staphyloma, macular atrophy, ruptures in Bruch’s membrane, pathologic choroidal neovascularization, and different degrees of myopic traction maculopathy. Purpose: To report the structural, functional and perfusional outcomes in patients underwent surgery for different stages of myopic traction maculopathy (MTM). Methods: A retrospective, consecutive, comparative, interventional, one-surgeon, case-control study was conducted in 46 eyes of 34 individuals between April 2015 and May 2021. Participants included normal emmetropic eyes (Control emmetropia, n = 25), healthy myopic eyes (Control high myopia, n = 20), and operated and structurally fully resolved myopic eyes with different stages of MTM (Surgically treated group, n = 46). Long-term postoperative functional and perfusional follow-up evaluations were performed with spectral domain-optical coherence tomography (SD-OCT) and OCT angiography. The primary outcome measure included long-term functional, structural and perfusion macular status across groups. Results: Forty-six eyes in 34 patients were included in the study group, with both eyes affected in 12 (26.3%) patients. The mean axial length was 29.89 ± 1.67 mm. The preoperative logMAR was 1.29 ± 0.54 and the postoperative logMAR was 0.60 ± 0.52 (P Conclusion: Compared to emmetropic and healthy myopic eyes, surgically-resolved MTM eyes generally have larger superficial foveal avascular zone area, lower vessel density, smaller choriocapillaris flow area, thinner central subfoveal thickness, and more macular defects. Eyes with stage III or IV MTM had larger deviation compared to eyes at earlier stages. Visual function change after surgery was associated with superficial foveal avascular zone area. Better functional, structural and perfusion index outcomes were observed when highly myopic eyes underwent early surgery.展开更多
Dramatic advances in retinal imaging technology over the last two decades have significantly improved our understanding of the natural history and pathophysiology of non-neovascular age-related macular degeneration(AM...Dramatic advances in retinal imaging technology over the last two decades have significantly improved our understanding of the natural history and pathophysiology of non-neovascular age-related macular degeneration(AMD).Currently,aside from micronutrient supplements,there are no proven treatments for non-neovascular or dry AMD.Recently,a number of pharmacological agents have been evaluated or are under evaluation for treatment of patients with end-stage dry AMD manifesting as geographic atrophy(GA).It may preferable,however,to intervene earlier in the disease before the development of irreversible loss of visual function.Earlier intervention would require a more precise understanding of biomarkers which may increase the risk of progression from early and intermediate stages to the late stage of the disease.The development of optical coherence tomography angiography(OCTA)has allowed the layers of the retinal microcirculation and choriocapillaris(CC)to be visualized and quantified.Flow deficits in the CC have been observed to increase with age,particularly centrally,and these flow deficits appear to worsen with development and progression of AMD.As such,OCTA-based CC assessment appears to be a valuable new biomarker in our assessment and risk-stratification of AMD.Alterations in the CC may also provide new insights into the pathophysiology of the disease.Enhancement of choriocapillaris function may also prove to be a target of future therapeutic strategies or as a biomarker to monitor the effectiveness of therapy.As such,CC imaging may be anticipated to be an integral tool in the management of dry AMD.展开更多
BACKGROUND Small blood vessels in the eyes are more susceptible to injury,which can lead to complications.However,since diabetic retinopathy is often a serious clinical condition,most of this study focuses on the vasc...BACKGROUND Small blood vessels in the eyes are more susceptible to injury,which can lead to complications.However,since diabetic retinopathy is often a serious clinical condition,most of this study focuses on the vascular system of the choroid.As part of this study,we looked at how gymnemic acid(from Gymnema sylvestre)and glabridin(from Glycyrrhiza glabra,or licorice)might help diabetic rats’choroid structural change and blood vessels.AIM To explore the effects of glabridin and gymnemic acid on the structural changes of the choroidal layer and choriocapillaris as well as the expression of vascular endothelial growth factor(VEGF)and cluster of differentiation(CD)31 in diabetic rat’s eye.METHODS The male Wistar rats were separated into five groups:The control group(control),the diabetic group(DM),the diabetic rats treated with glabridin 40 mg/kg body weight(DM+GB),the diabetic rats treated with gymnemic acid 400 mg/kg body weight(DM+GM),and the diabetic rats treated with glyburide 4 mg/kg body weight(DM+GR).RESULTS There was an increase in the thickness of both the choroid layer and the wall of the arteries in the DM.A decrease in vascularity and choroidal impairment was found in DM rats.After eight weeks of experimentation,the choroidal thickness increased,and the walls of choroid arteries.The choroidal thickness in the DM+GB was 15.69±1.54μm,DM+GM was 14.84±1.31,and DM+GR groups was 16.45±1.15 when compared with DM group(27.22±2.05),the walls thickness of choroid arteries in the DM+GB was 10.23±1.11,DM+GM was 10.41±1.44,and DM+GR was 9.80±1.78 when compared with DM group(16.35±5.01),The expression of VEGF and CD31 was lower compared to the DM group.CONCLUSION In diabetic choroidopathy,hyperglycemia and inflammation cause damage to the neurovascular unit and bloodretinal barrier.Anti-VEGF treatments can slow or reverse the progression of the disease.According to current research findings,glabridin and gymnemic acid can reduce damage to the choroid,which is a factor that can sometimes result in vision loss.展开更多
Background:This study aims to examine interocular differences in the choroidal thickness and vascular density of the choriocapillaris in anisometropic myopes and to further explore the relationship between choroidal b...Background:This study aims to examine interocular differences in the choroidal thickness and vascular density of the choriocapillaris in anisometropic myopes and to further explore the relationship between choroidal blood flow and myopia.Methods:The sample comprised 44 participants with anisometropic myopia,aged 9 to 18 years,with normal bestcorrected visual acuity.All participants underwent a series of examinations,including spherical equivalent refraction(SER)and axial length(AL),measured by a Lenstar optical biometer and optical coherence tomography angiography(OCTA)scanner.OCT measured the choroidal thickness,vascular density,and flow voids of the choriocapillaris,and a customized algorithm was implemented in MATLAB R2017a with the post-correction of AL.The choroidal thickness was measured at the fovea and 0.5,1.0,1.5,2.0,2.5,and 3.0 mm nasally,temporally,inferiorly,and superiorly to the fovea.The vascular density and the flow voids of the choriocapillaris were measured at a 0.6-mm-diameter central circle,and the 0.6-2.5 mm diameter circle in the nasal,temporal,inferior,and superior regions.Repeated-measured ANOVAs were used to analyze the interocular differences.Partial correlations with the K value and age adjustments were used to study the relationships between the choroidal thickness,the choriocapillaris vascular density and flow voids,the SER and AL.Results:The choroidal thickness of the more myopic eyes was significantly thinner than less myopic eyes(P≤0.001),and the flow voids in the more myopic eyes were more than less myopic eyes(P=0.002).There was no significant difference in the vascular density of the choriocapillaris between the more and less myopic eyes(P=0.525).However,when anisometropia was more than 1.50 D,the vascular density of choriocapillaris in the more myopic eyes was significantly less than the less myopic eyes(P=0.026).The interocular difference of the choroidal thickness was significantly correlated with the interocular difference in SER and AL in the center,superior,and inferior regions but not in the nasal or temporal regions.The interocular differences of the vascular density and the flow voids of the choriocapillaris were not correlated with the interocular difference of SER and AL.Conclusions:The choroidal thickness is thinner in the more myopic eyes.The flow void is increased,and the vascular density of the choriocapillaris is reduced in the more myopic eyes of children with anisometropia exceeding 1.50 D.展开更多
Age-related macular degeneration(AMD)is a leading cause of central vision loss worldwide.The progression of dry AMD from early to intermediate stages is primarily characterized by increasing drusen formation and adver...Age-related macular degeneration(AMD)is a leading cause of central vision loss worldwide.The progression of dry AMD from early to intermediate stages is primarily characterized by increasing drusen formation and adverse impact on outer retinal cells.Late stage AMD consists of either geographic atrophy(GA),the non-exudative(dry)AMD subtype,or choroidal neovascularization,the exudative(wet)AMD subtype.GA is characterized by outer retinal and choroidal atrophy,specifically the photoreceptor layer,RPE,and choriocapillaris.Much remains to be discovered regarding the pathogenesis of AMD progression and subsequent development of GA.As the functionality of all three layers is closely linked,the temporal sequence of events that end up in atrophy is important in the understanding of the pathogenic pathway of the disease.The advent of OCTA,and particularly of swept-source technology,has allowed for depth-resolved imaging of retinal vasculature and the choriocapillaris.With the use of OCTA,recent studies demonstrate that choriocapillaris flow alterations are closely associated with the development and progression of AMD.Such changes may even possibly offer predictive value in determining progression of GA.This article reviews studies demonstrating choriocapillaris changes in dry AMD and summarizes the existing literature on the potential role of the choriocapillaris as a key factor in the pathogenesis of AMD.展开更多
文摘The responses of choriocapillary endothelial cells(CCE) and retinal capillary endothelial cells(RCE) in culture,in terms of phosphoinositide(PI) breakdown and cellular mitogenesis, to retinal pigment epithelial cell(RPE)-conditioned medium and vasoactive agents have been compared. RPE-conditioned medium did not induce PI breakdown in either type of cell. However, it stimulated DNA synthesis in CCE but not in RCE. Bradykinin(BDK) acted as both a fast signaling and a slow mitogenic factor on CCE, but BDK did not affect PI turnover or DNA synthesis in RCE. In contrast, thrombin stimulated PI turnover in RCE but not in CCE, though it did not induce 3H-thymidine incorporation into either type of cell. These differences in cellular functions between CCE and RCE following stimulation suggest that induction of DNA synthesis and receptor-mediated PI turnover by external factors is determined, at least in part, by the origin of the capillary endothelial cell. Therefore, extrapolation to CCE pathophysiology from experiments using endothelial cells from other capillary origins may not be valid.
文摘AIMTo report the appearance of choriocapillaris atrophy after combined high dose intravitreal triamcinolone acetonide (TA) and photodynamic therapy (PDT) to treat choroidal neovascularization (CNV) associated with age related macular degeneration (AMD).
文摘A simple mathematical model for the exudative retinal detachment has been developed. The model takes into consideration a typical retinal blister with unknown shape and the fluid flow caused by its accumulation in the subretinal space through the fluid-leakage into the subretinal space from the choriocapillar is across the outer blood-retina barrier described by Darcy’s law. The theory of bending beams is applied to model the deformation of the retinal blister. The boundary value problem describing the retinal deformation in dimensionless form is solved using the perturbation method. The computational results for the retinal deformation are presented through graphs to illustrate the sensitivity of the deformation to the elastic modulus, the moment of inertia and intraocular pressure and discussed.
文摘Background: Information on the long-term perfusion status of patients after successful surgery for giant retinal tear (GRT) macula-off rhegmatogenous retinal detachment (RRD) is limited. Purpose: To examine long-term structural, functional, and perfusion outcomes in normal control eyes and eyes treated for different degrees of GRT-associated extensions of RRD. Methods: One emmetropic normal eye (control), one healthy highly myopic eye (control myopic), and three eyes surgically treated for GRT (surgical), were included in the study for a long-term comparison of study outcomes. The surgical eyes were classified based on the degree of GRT-associated RRD extension as follows: one eye with GRT-associated RRD extension ˚one eye with GRT-associated RRD extension between 180˚- 270˚and one eye with GRT-associated RRD extension > 270˚. Structural, functional, and perfusion outcomes were compared with those of the control eyes. Results: All three eyes were phakic and the condition was monocular. The mean age of the patients was 48.67 ± 8.50 years (range, 39 - 55 years). All three eyes had GRT macula-off RRD. The mean preoperative time for GRT surgery was 1.2 weeks. The mean pre- and postoperative best corrected visual acuities (BCVA) were 1.87 logMAR and 0.46 logMAR, respectively. The mean postoperative follow-up period was 19.67 ± 5.69 months. Proliferative vitreoretinopathy resulted in multiple surgeries in one eye (31.5%). Long-term postoperative optical coherence tomography (OCT) showed abnormal retinal thickness, ellipsoid zone disruption, and external limiting membrane line discontinuities in one eye. OCT angiography yielded abnormal perfusion indices in the surgically treated eyes. Conclusions: Our data showed multiple structural alterations in spectral-domain OCT biomarkers. One eye that developed secondary epiretinal membrane (ERM) proliferation showed a significantly improved BCVA after proliferation and internal limiting membrane were removed. Perfusion findings were correlated with the final BCVA. Despite a fully reattached retina without ERM proliferation, GRT-associated RRD has a guarded functional prognosis.
文摘Background: Pathological myopia can be complicated by the presence of posterior staphyloma, macular atrophy, ruptures in Bruch’s membrane, pathologic choroidal neovascularization, and different degrees of myopic traction maculopathy. Purpose: To report the structural, functional and perfusional outcomes in patients underwent surgery for different stages of myopic traction maculopathy (MTM). Methods: A retrospective, consecutive, comparative, interventional, one-surgeon, case-control study was conducted in 46 eyes of 34 individuals between April 2015 and May 2021. Participants included normal emmetropic eyes (Control emmetropia, n = 25), healthy myopic eyes (Control high myopia, n = 20), and operated and structurally fully resolved myopic eyes with different stages of MTM (Surgically treated group, n = 46). Long-term postoperative functional and perfusional follow-up evaluations were performed with spectral domain-optical coherence tomography (SD-OCT) and OCT angiography. The primary outcome measure included long-term functional, structural and perfusion macular status across groups. Results: Forty-six eyes in 34 patients were included in the study group, with both eyes affected in 12 (26.3%) patients. The mean axial length was 29.89 ± 1.67 mm. The preoperative logMAR was 1.29 ± 0.54 and the postoperative logMAR was 0.60 ± 0.52 (P Conclusion: Compared to emmetropic and healthy myopic eyes, surgically-resolved MTM eyes generally have larger superficial foveal avascular zone area, lower vessel density, smaller choriocapillaris flow area, thinner central subfoveal thickness, and more macular defects. Eyes with stage III or IV MTM had larger deviation compared to eyes at earlier stages. Visual function change after surgery was associated with superficial foveal avascular zone area. Better functional, structural and perfusion index outcomes were observed when highly myopic eyes underwent early surgery.
文摘Dramatic advances in retinal imaging technology over the last two decades have significantly improved our understanding of the natural history and pathophysiology of non-neovascular age-related macular degeneration(AMD).Currently,aside from micronutrient supplements,there are no proven treatments for non-neovascular or dry AMD.Recently,a number of pharmacological agents have been evaluated or are under evaluation for treatment of patients with end-stage dry AMD manifesting as geographic atrophy(GA).It may preferable,however,to intervene earlier in the disease before the development of irreversible loss of visual function.Earlier intervention would require a more precise understanding of biomarkers which may increase the risk of progression from early and intermediate stages to the late stage of the disease.The development of optical coherence tomography angiography(OCTA)has allowed the layers of the retinal microcirculation and choriocapillaris(CC)to be visualized and quantified.Flow deficits in the CC have been observed to increase with age,particularly centrally,and these flow deficits appear to worsen with development and progression of AMD.As such,OCTA-based CC assessment appears to be a valuable new biomarker in our assessment and risk-stratification of AMD.Alterations in the CC may also provide new insights into the pathophysiology of the disease.Enhancement of choriocapillaris function may also prove to be a target of future therapeutic strategies or as a biomarker to monitor the effectiveness of therapy.As such,CC imaging may be anticipated to be an integral tool in the management of dry AMD.
基金Supported by the Prince of Songkla University Research Fund,No.SCI6302040S。
文摘BACKGROUND Small blood vessels in the eyes are more susceptible to injury,which can lead to complications.However,since diabetic retinopathy is often a serious clinical condition,most of this study focuses on the vascular system of the choroid.As part of this study,we looked at how gymnemic acid(from Gymnema sylvestre)and glabridin(from Glycyrrhiza glabra,or licorice)might help diabetic rats’choroid structural change and blood vessels.AIM To explore the effects of glabridin and gymnemic acid on the structural changes of the choroidal layer and choriocapillaris as well as the expression of vascular endothelial growth factor(VEGF)and cluster of differentiation(CD)31 in diabetic rat’s eye.METHODS The male Wistar rats were separated into five groups:The control group(control),the diabetic group(DM),the diabetic rats treated with glabridin 40 mg/kg body weight(DM+GB),the diabetic rats treated with gymnemic acid 400 mg/kg body weight(DM+GM),and the diabetic rats treated with glyburide 4 mg/kg body weight(DM+GR).RESULTS There was an increase in the thickness of both the choroid layer and the wall of the arteries in the DM.A decrease in vascularity and choroidal impairment was found in DM rats.After eight weeks of experimentation,the choroidal thickness increased,and the walls of choroid arteries.The choroidal thickness in the DM+GB was 15.69±1.54μm,DM+GM was 14.84±1.31,and DM+GR groups was 16.45±1.15 when compared with DM group(27.22±2.05),the walls thickness of choroid arteries in the DM+GB was 10.23±1.11,DM+GM was 10.41±1.44,and DM+GR was 9.80±1.78 when compared with DM group(16.35±5.01),The expression of VEGF and CD31 was lower compared to the DM group.CONCLUSION In diabetic choroidopathy,hyperglycemia and inflammation cause damage to the neurovascular unit and bloodretinal barrier.Anti-VEGF treatments can slow or reverse the progression of the disease.According to current research findings,glabridin and gymnemic acid can reduce damage to the choroid,which is a factor that can sometimes result in vision loss.
基金supported by the Health Technology Plan Project of Zhejiang Province(2018KY542 and 2021KY808)the Key Research and Development Program of Zhejiang Province(2021C03102).
文摘Background:This study aims to examine interocular differences in the choroidal thickness and vascular density of the choriocapillaris in anisometropic myopes and to further explore the relationship between choroidal blood flow and myopia.Methods:The sample comprised 44 participants with anisometropic myopia,aged 9 to 18 years,with normal bestcorrected visual acuity.All participants underwent a series of examinations,including spherical equivalent refraction(SER)and axial length(AL),measured by a Lenstar optical biometer and optical coherence tomography angiography(OCTA)scanner.OCT measured the choroidal thickness,vascular density,and flow voids of the choriocapillaris,and a customized algorithm was implemented in MATLAB R2017a with the post-correction of AL.The choroidal thickness was measured at the fovea and 0.5,1.0,1.5,2.0,2.5,and 3.0 mm nasally,temporally,inferiorly,and superiorly to the fovea.The vascular density and the flow voids of the choriocapillaris were measured at a 0.6-mm-diameter central circle,and the 0.6-2.5 mm diameter circle in the nasal,temporal,inferior,and superior regions.Repeated-measured ANOVAs were used to analyze the interocular differences.Partial correlations with the K value and age adjustments were used to study the relationships between the choroidal thickness,the choriocapillaris vascular density and flow voids,the SER and AL.Results:The choroidal thickness of the more myopic eyes was significantly thinner than less myopic eyes(P≤0.001),and the flow voids in the more myopic eyes were more than less myopic eyes(P=0.002).There was no significant difference in the vascular density of the choriocapillaris between the more and less myopic eyes(P=0.525).However,when anisometropia was more than 1.50 D,the vascular density of choriocapillaris in the more myopic eyes was significantly less than the less myopic eyes(P=0.026).The interocular difference of the choroidal thickness was significantly correlated with the interocular difference in SER and AL in the center,superior,and inferior regions but not in the nasal or temporal regions.The interocular differences of the vascular density and the flow voids of the choriocapillaris were not correlated with the interocular difference of SER and AL.Conclusions:The choroidal thickness is thinner in the more myopic eyes.The flow void is increased,and the vascular density of the choriocapillaris is reduced in the more myopic eyes of children with anisometropia exceeding 1.50 D.
基金supported in part by a grant from the Macula Vision Research Foundation.
文摘Age-related macular degeneration(AMD)is a leading cause of central vision loss worldwide.The progression of dry AMD from early to intermediate stages is primarily characterized by increasing drusen formation and adverse impact on outer retinal cells.Late stage AMD consists of either geographic atrophy(GA),the non-exudative(dry)AMD subtype,or choroidal neovascularization,the exudative(wet)AMD subtype.GA is characterized by outer retinal and choroidal atrophy,specifically the photoreceptor layer,RPE,and choriocapillaris.Much remains to be discovered regarding the pathogenesis of AMD progression and subsequent development of GA.As the functionality of all three layers is closely linked,the temporal sequence of events that end up in atrophy is important in the understanding of the pathogenic pathway of the disease.The advent of OCTA,and particularly of swept-source technology,has allowed for depth-resolved imaging of retinal vasculature and the choriocapillaris.With the use of OCTA,recent studies demonstrate that choriocapillaris flow alterations are closely associated with the development and progression of AMD.Such changes may even possibly offer predictive value in determining progression of GA.This article reviews studies demonstrating choriocapillaris changes in dry AMD and summarizes the existing literature on the potential role of the choriocapillaris as a key factor in the pathogenesis of AMD.