Ophthalmic ArteryRetinal Artery OcclusionRetinal ArteryCiliary ArteriesArteriesUltrasonography, Doppler, ColorCarotid Artery, InternalBlood Flow VelocityCerebral ArteriesOrbitOphthalmodynamometryArterial Occlusive DiseasesVision, EntopticPulmonary ArteryEthmoid SinusitisCarotid Artery DiseasesSubarachnoid Hemorrhage, TraumaticCircle of WillisEyeFemoral ArteryCarotid ArteriesAmaurosis FugaxUltrasonography, Doppler, PulsedEmbolization, TherapeuticRegional Blood FlowCerebral AngiographyCollateral CirculationCarotid Artery ThrombosisRetinal VeinCarotid Artery, ExternalRenal ArteryLaser-Doppler FlowmetryBasilar ArteryMesenteric ArteriesCerebrovascular CirculationCoronary OcclusionEthmoid SinusCarotid StenosisIntraocular PressureReceptor, Muscarinic M5Balloon OcclusionIliac ArteryEnbucrilateFundus OculiVertebral ArteryRetinal NeoplasmsOptic Neuropathy, IschemicAngiographyRetinal Vein OcclusionBlood PressureRetinoblastomaUltrasonography, DopplerCranial Fossa, AnteriorCoronary Artery BypassUltrasonography, Doppler, TranscranialIntracranial AneurysmPulsatile FlowRadial ArteryInfarction, Middle Cerebral ArterySubclavian ArteryMammary ArteriesHemodynamicsReceptor, Muscarinic M3Coronary VesselsVasodilation