Background and Objective:In recent years,a number of studies focused on the choroidal venous outflow have improved our understanding of the nature of the pachychoroid spectrum disorders(PSD)and highlighted the role of...Background and Objective:In recent years,a number of studies focused on the choroidal venous outflow have improved our understanding of the nature of the pachychoroid spectrum disorders(PSD)and highlighted the role of the intervortex venous anastomoses(IVA)as a basic characteristic of vascular remodeling of the choroid.However,the imaging data,quantitative and qualitative characteristics of IVA,as well as their relationship with other choroidal parameters,have not been systematically reviewed and summarized.The objective of this review was to summarize data on the prevalence and pathophysiological role of IVA and associated vascular changes of the choroid.Methods:This was a narrative review of available literature from databases published in English before March 2025.We analyze the results of studies reporting the status of IVA and associated vascular remodeling of the choroid in healthy eyes and eyes with various retinochoroidal disorders.Key Content and Findings:We highlight imaging techniques that have been used to display the IVA in the clinical and experimental settings including indocyanine green angiography(ICGA)and en face optical coherence tomography(OCT).We report on the prevalence of IVA in healthy eyes and eyes with various retinochoroidal disorders and indicate the potential role of the sclera in the impairment of choroidal venous outflow leading to activation of the IVA.We summarize the association of IVA with a number of abnormal characteristics of the choroid including choroidal hyperpermeability and thickening,asymmetry of the running pattern of choroidal vessels,and choroidal thickness,increased diameter of large vessels,as well as the increase of choroidal vascularity.Conclusions:IVA represent one of the few biomarkers reflecting the deep pathophysiological mechanisms of PSD,closely linked to choroidal vascular remodeling.En face OCT can provide comprehensive,clinically relevant data on this biomarker.However,further standardization is required in defining,imaging,and quantifying IVA.展开更多
An object or system is said to be chiral if it cannot be superimposed on its mirror reflection.Chirality is ubiquitous in nature,for example,in protein molecules and chiral phonons—acoustic waves carrying angular mom...An object or system is said to be chiral if it cannot be superimposed on its mirror reflection.Chirality is ubiquitous in nature,for example,in protein molecules and chiral phonons—acoustic waves carrying angular momentum—which are usually either intrinsically present or magnetically excited in suitable materials.Here,we report the use of intervortex forward Brillouin scattering to optically excite chiral flexural phonons in a twisted photonic crystal fiber,which is itself a chiral material capable of robustly preserving circularly polarized optical vortex states.The phonons induce a spatiotemporal rotating linear birefringence that acts back on the optical vortex modes,coupling them together.We demonstrate intervortex frequency conversion under the mediation of chiral flexural phonons and show that,for the same phonons,backward and forward intervortex conversion occurs at different wavelengths.The results open up,to our knowledge,new perspectives for Brillouin scattering and the chiral flexural phonons offer new opportunities for vortex-related information processing and multi-dimensional vectorial optical sensing.展开更多
文摘Background and Objective:In recent years,a number of studies focused on the choroidal venous outflow have improved our understanding of the nature of the pachychoroid spectrum disorders(PSD)and highlighted the role of the intervortex venous anastomoses(IVA)as a basic characteristic of vascular remodeling of the choroid.However,the imaging data,quantitative and qualitative characteristics of IVA,as well as their relationship with other choroidal parameters,have not been systematically reviewed and summarized.The objective of this review was to summarize data on the prevalence and pathophysiological role of IVA and associated vascular changes of the choroid.Methods:This was a narrative review of available literature from databases published in English before March 2025.We analyze the results of studies reporting the status of IVA and associated vascular remodeling of the choroid in healthy eyes and eyes with various retinochoroidal disorders.Key Content and Findings:We highlight imaging techniques that have been used to display the IVA in the clinical and experimental settings including indocyanine green angiography(ICGA)and en face optical coherence tomography(OCT).We report on the prevalence of IVA in healthy eyes and eyes with various retinochoroidal disorders and indicate the potential role of the sclera in the impairment of choroidal venous outflow leading to activation of the IVA.We summarize the association of IVA with a number of abnormal characteristics of the choroid including choroidal hyperpermeability and thickening,asymmetry of the running pattern of choroidal vessels,and choroidal thickness,increased diameter of large vessels,as well as the increase of choroidal vascularity.Conclusions:IVA represent one of the few biomarkers reflecting the deep pathophysiological mechanisms of PSD,closely linked to choroidal vascular remodeling.En face OCT can provide comprehensive,clinically relevant data on this biomarker.However,further standardization is required in defining,imaging,and quantifying IVA.
文摘An object or system is said to be chiral if it cannot be superimposed on its mirror reflection.Chirality is ubiquitous in nature,for example,in protein molecules and chiral phonons—acoustic waves carrying angular momentum—which are usually either intrinsically present or magnetically excited in suitable materials.Here,we report the use of intervortex forward Brillouin scattering to optically excite chiral flexural phonons in a twisted photonic crystal fiber,which is itself a chiral material capable of robustly preserving circularly polarized optical vortex states.The phonons induce a spatiotemporal rotating linear birefringence that acts back on the optical vortex modes,coupling them together.We demonstrate intervortex frequency conversion under the mediation of chiral flexural phonons and show that,for the same phonons,backward and forward intervortex conversion occurs at different wavelengths.The results open up,to our knowledge,new perspectives for Brillouin scattering and the chiral flexural phonons offer new opportunities for vortex-related information processing and multi-dimensional vectorial optical sensing.
