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Josef Flammer - One of the best experts on this subject based on the ideXlab platform.
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Refractoriness to the Effect of Endothelin-1 in Porcine Ciliary Arteries
Journal of ocular pharmacology and therapeutics : the official journal of the Association for Ocular Pharmacology and Therapeutics, 2013Co-Authors: Katarzyna Konieczka, Andreas Schoetzau, Albert Neutzner, Andreas J. Flammer, Tatjana Binggeli, Josef FlammerAbstract:Abstract Purpose: Endothelin-1 (ET) is an important molecule in vascular physiology. After an acute stimulation with ET, vessels are to some extent temporarily refractory to further stimulation. However, few details are known about this phenomenon. The aim of our study was to verify the existence of refractoriness in ophthalmic Ciliary Arteries and, if present, to analyze its time course. Methods: Twenty freshly isolated porcine Ciliary Arteries were placed in a myograph system to measure isometric forces. Each vessel was stimulated with 10−7 M ET twice. The experiment was performed in 5 groups of vessels, which differed in the time interval between the initial and the second stimulation with ET. The intervals were 15 min, 30 min, 1 h, 2 h, and 4 h, respectively. Results: The vasoconstrictive response to re-exposure to ET was time-dependently reduced. The response was lowest after 15 min (22% of baseline response), and then the sensitivity slowly recovered and was finally normal again after 4 h. Conclusio...
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Effect of avosentan (SPP-301) in porcine Ciliary Arteries.
Current Eye Research, 2011Co-Authors: Katarzyna Konieczka, Andreas Schoetzau, Albert Neutzner, Peter Meyer, Maneli Mozaffarieh, Josef FlammerAbstract:Purpose: To investigate the vasoactive effect of ETA-endothelin receptor antagonists avosentan (SPP-301) and BQ-123 in isolated porcine Ciliary Arteries with and without endothelium. To investigate the effect of avosentan on the endothelin-1 induced contractions in comparison with BQ-123 and BQ-788 (ETB-endothelin receptor antagonist) in isolated porcine Ciliary Arteries with and without endothelium.Methods: Vessels were placed in a myograph system to measure isometric forces. In a first set of experiments, quiescent vessels were exposed, cumulatively, to increasing concentrations of avosentan and BQ-123 (10−9 M–3 × 10−6 M). In a second set of experiments, quiescent vessels were first incubated with avosentan (10−6 M and 10−8 M), BQ-123 (10−6 M), and BQ-788 (10−6 M), respectively. Then the vessels were exposed, cumulatively, to increasing concentrations of endothelin-1 (10−12 M–3 × 10−8 M). Each set of experiments was conducted in the vessels with and without endothelium.Results: Cumulative concentrations...
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Effect of avosentan (SPP-301) in porcine Ciliary Arteries.
Current Eye Research, 2011Co-Authors: Katarzyna Konieczka, Andreas Schoetzau, Albert Neutzner, Peter Meyer, Maneli Mozaffarieh, Josef FlammerAbstract:Purpose: To investigate the vasoactive effect of ETA-endothelin receptor antagonists avosentan (SPP-301) and BQ-123 in isolated porcine Ciliary Arteries with and without endothelium. To investigate the effect of avosentan on the endothelin-1 induced contractions in comparison with BQ-123 and BQ-788 (ETB-endothelin receptor antagonist) in isolated porcine Ciliary Arteries with and without endothelium.Methods: Vessels were placed in a myograph system to measure isometric forces. In a first set of experiments, quiescent vessels were exposed, cumulatively, to increasing concentrations of avosentan and BQ-123 (10−9 M–3 × 10−6 M). In a second set of experiments, quiescent vessels were first incubated with avosentan (10−6 M and 10−8 M), BQ-123 (10−6 M), and BQ-788 (10−6 M), respectively. Then the vessels were exposed, cumulatively, to increasing concentrations of endothelin-1 (10−12 M–3 × 10−8 M). Each set of experiments was conducted in the vessels with and without endothelium.Results: Cumulative concentrations...
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Vasoactive Responses of U46619, PGF2α, Latanoprost, and Travoprost in Isolated Porcine Ciliary Arteries
Investigative ophthalmology & visual science, 2006Co-Authors: Ineta Vysniauskiene, Josef Flammer, Reto Allemann, Ivan O HaefligerAbstract:PURPOSE To compare the vasoactive properties of the prostanoids U46619 (thromboxane A2 analogue), prostaglandin F(2alpha) (PGF(2alpha)), latanoprost free acid, and travoprost free acid in isolated porcine Ciliary Arteries. METHODS In a myograph system (isometric force measurement), quiescent vessels were exposed (cumulatively) to U46619, PGF(2alpha), latanoprost, or travoprost (0.1 nM-0.1 mM). Experiments were also conducted in the presence of SQ 29548 (TP-receptor antagonist; 3-10 microM) or AL-8810 (FP-receptor antagonist; 3-30 microM). Contractions were expressed as the percentage of 100 mM potassium chloride-induced contractions. RESULTS In quiescent vessels, contractions (concentration-response curves) induced by (0.1 mM) PGF(2alpha) (87.9% +/- 3.5%), U46619 (66.7% +/- 4.1%), and latanoprost (62.9% +/- 3.6%) were more pronounced (P < or = 0.001) than those induced by travoprost (23.0% +/- 4.4%). Concentration-response curves for PGF(2alpha), latanoprost, and travoprost were preceded by a smaller contraction peak (0.1 microM) that was higher (P < or = 0.05) for travoprost (24.4% +/- 2.8%) than for PGF(2alpha) (12.9% +/- 4.6%), but not different (P = 0.58) from latanoprost (22.0% +/- 3.0%). The 50% maximal contraction (PD50: negative log M concentration) of U46619 (-8.05 +/- 0.13) was lower (P < or = 0.001) than those of latanoprost (-5.65 +/- 0.10), PGF(2alpha) (-5.49 +/- 0.14), and travoprost (-5.12 +/- 0.52). Contractions were inhibited (P < or = 0.05-0.001) either by SQ 29548 or AL-8810. CONCLUSIONS In isolated porcine Ciliary Arteries, all prostanoids tested induced contractions. Among them, travoprost appeared to be the least potent and U46619 the most efficient.
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Adrenomedullin-induced endothelium-dependent relaxation in porcine Ciliary Arteries.
Investigative ophthalmology & visual science, 2003Co-Authors: Eike S. Dettmann, Josef Flammer, Ineta Vysniauskiene, Ivan O HaefligerAbstract:PURPOSE To investigate adrenomedullin-induced relaxation in isolated porcine Ciliary Arteries. METHODS In a myograph system (isometric force measurement), precontracted vessels ( approximately 0.1 micro M U46619; thromboxane A(2) analogue or approximately 10 nM endothelin-1) were exposed, in a cumulative manner, to increasing concentrations of adrenomedullin (1 nM to 1 micro M) in the presence or absence of different drugs. Some experiments were conducted in vessels with nonfunctional (intentionally mechanically damaged) endothelium. RESULTS Adrenomedullin evoked marked relaxation [maximum relaxation (Rel(max)): 85.5 +/- 3.0%; negative log M concentration inducing 50% of Rel(max) (pD(2)): 7.4 +/- 0.1] in comparison to time-controls (Rel(max): 19.2 +/-4.8%; P 0.50) from that observed in vessels with nonfunctional endothelium. CONCLUSIONS In isolated porcine Ciliary Arteries, adrenomedullin induces relaxation that involves CGRP(1) receptors and is in part endothelium dependent. Endothelium-dependent relaxation was blocked by some potassium channel inhibitors, suggesting the possible release of an endothelium-derived hyperpolarizing factor (EDHF).
Takashi Tokoro - One of the best experts on this subject based on the ideXlab platform.
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Zinn–Haller arterial ring observed by ICG angiography in high myopia
British Journal of Ophthalmology, 1998Co-Authors: Kyoko Ohno-matsui, Soh Futagami, Satoshi Yamashita, Takashi TokoroAbstract:AIMS To delineate the entire Zinn–Haller arterial ring angiographically in vivo. METHODS 382 highly myopic eyes (210 patients) with refractive errors greater than −8.25 D were examined using indocyanine green (ICG) videoangiography. A control group of 80 eyes (40 patients) had refractive errors within plano +/− 3 D. RESULTS The Zinn–Haller ring was visible in 206 of 382 highly myopic eyes (53.9%) by ICG angiography. Although only a part of the Zinn–Haller ring was visible in 162 of 206 eyes, in the remaining 44 eyes it was observed almost completely around the optic nerve head. No anastomotic channels between lateral and medial short posterior Ciliary Arteries were filled by ICG angiography. In 22 of the 44 eyes (50.0%) the Zinn–Haller ring was supplied by branches of the lateral and medial short posterior Ciliary Arteries; in seven eyes, it was supplied only by the lateral short posterior Ciliary artery; and in seven eyes, it was supplied only by the medial short posterior Ciliary artery. In none of the control subjects was the Zinn–Haller ring visible by ICG angiography. CONCLUSIONS The Zinn–Haller ring observed by ICG angiography was not a complete collateral circle between lateral and medial posterior Ciliary Arteries. Also, the patterns in supply vessels to the Zinn–Haller ring varied. ICG angiography made possible the detailed observation of the Zinn–Haller ring in human eyes in vivo.
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zinn haller arterial ring observed by icg angiography in high myopia
British Journal of Ophthalmology, 1998Co-Authors: Kyoko Ohnomatsui, Soh Futagami, Satoshi Yamashita, Takashi TokoroAbstract:AIMS To delineate the entire Zinn–Haller arterial ring angiographically in vivo. METHODS 382 highly myopic eyes (210 patients) with refractive errors greater than −8.25 D were examined using indocyanine green (ICG) videoangiography. A control group of 80 eyes (40 patients) had refractive errors within plano +/− 3 D. RESULTS The Zinn–Haller ring was visible in 206 of 382 highly myopic eyes (53.9%) by ICG angiography. Although only a part of the Zinn–Haller ring was visible in 162 of 206 eyes, in the remaining 44 eyes it was observed almost completely around the optic nerve head. No anastomotic channels between lateral and medial short posterior Ciliary Arteries were filled by ICG angiography. In 22 of the 44 eyes (50.0%) the Zinn–Haller ring was supplied by branches of the lateral and medial short posterior Ciliary Arteries; in seven eyes, it was supplied only by the lateral short posterior Ciliary artery; and in seven eyes, it was supplied only by the medial short posterior Ciliary artery. In none of the control subjects was the Zinn–Haller ring visible by ICG angiography. CONCLUSIONS The Zinn–Haller ring observed by ICG angiography was not a complete collateral circle between lateral and medial posterior Ciliary Arteries. Also, the patterns in supply vessels to the Zinn–Haller ring varied. ICG angiography made possible the detailed observation of the Zinn–Haller ring in human eyes in vivo.
Ivan O Haefliger - One of the best experts on this subject based on the ideXlab platform.
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Vasoactive Responses of U46619, PGF2α, Latanoprost, and Travoprost in Isolated Porcine Ciliary Arteries
Investigative ophthalmology & visual science, 2006Co-Authors: Ineta Vysniauskiene, Josef Flammer, Reto Allemann, Ivan O HaefligerAbstract:PURPOSE To compare the vasoactive properties of the prostanoids U46619 (thromboxane A2 analogue), prostaglandin F(2alpha) (PGF(2alpha)), latanoprost free acid, and travoprost free acid in isolated porcine Ciliary Arteries. METHODS In a myograph system (isometric force measurement), quiescent vessels were exposed (cumulatively) to U46619, PGF(2alpha), latanoprost, or travoprost (0.1 nM-0.1 mM). Experiments were also conducted in the presence of SQ 29548 (TP-receptor antagonist; 3-10 microM) or AL-8810 (FP-receptor antagonist; 3-30 microM). Contractions were expressed as the percentage of 100 mM potassium chloride-induced contractions. RESULTS In quiescent vessels, contractions (concentration-response curves) induced by (0.1 mM) PGF(2alpha) (87.9% +/- 3.5%), U46619 (66.7% +/- 4.1%), and latanoprost (62.9% +/- 3.6%) were more pronounced (P < or = 0.001) than those induced by travoprost (23.0% +/- 4.4%). Concentration-response curves for PGF(2alpha), latanoprost, and travoprost were preceded by a smaller contraction peak (0.1 microM) that was higher (P < or = 0.05) for travoprost (24.4% +/- 2.8%) than for PGF(2alpha) (12.9% +/- 4.6%), but not different (P = 0.58) from latanoprost (22.0% +/- 3.0%). The 50% maximal contraction (PD50: negative log M concentration) of U46619 (-8.05 +/- 0.13) was lower (P < or = 0.001) than those of latanoprost (-5.65 +/- 0.10), PGF(2alpha) (-5.49 +/- 0.14), and travoprost (-5.12 +/- 0.52). Contractions were inhibited (P < or = 0.05-0.001) either by SQ 29548 or AL-8810. CONCLUSIONS In isolated porcine Ciliary Arteries, all prostanoids tested induced contractions. Among them, travoprost appeared to be the least potent and U46619 the most efficient.
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Adrenomedullin-induced endothelium-dependent relaxation in porcine Ciliary Arteries.
Investigative ophthalmology & visual science, 2003Co-Authors: Eike S. Dettmann, Josef Flammer, Ineta Vysniauskiene, Ivan O HaefligerAbstract:PURPOSE To investigate adrenomedullin-induced relaxation in isolated porcine Ciliary Arteries. METHODS In a myograph system (isometric force measurement), precontracted vessels ( approximately 0.1 micro M U46619; thromboxane A(2) analogue or approximately 10 nM endothelin-1) were exposed, in a cumulative manner, to increasing concentrations of adrenomedullin (1 nM to 1 micro M) in the presence or absence of different drugs. Some experiments were conducted in vessels with nonfunctional (intentionally mechanically damaged) endothelium. RESULTS Adrenomedullin evoked marked relaxation [maximum relaxation (Rel(max)): 85.5 +/- 3.0%; negative log M concentration inducing 50% of Rel(max) (pD(2)): 7.4 +/- 0.1] in comparison to time-controls (Rel(max): 19.2 +/-4.8%; P 0.50) from that observed in vessels with nonfunctional endothelium. CONCLUSIONS In isolated porcine Ciliary Arteries, adrenomedullin induces relaxation that involves CGRP(1) receptors and is in part endothelium dependent. Endothelium-dependent relaxation was blocked by some potassium channel inhibitors, suggesting the possible release of an endothelium-derived hyperpolarizing factor (EDHF).
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Vasoactive properties of bimatoprost in isolated porcine Ciliary Arteries.
Klinische Monatsblatter fur Augenheilkunde, 2003Co-Authors: Reto Allemann, Josef Flammer, Ivan O HaefligerAbstract:BACKGROUND To investigate the vasoactive effect of bimatoprost (Lumigan), a new topical ocular hypotensive agent, in isolated porcine Ciliary Arteries. MATERIAL AND METHODS Arteries were placed in a myograph system to measure isometric forces. Quiescent vessels as well as vessels pre-contracted with either 10 nM endothelin-1 or 100 mM potassium chloride (KCl) were exposed, in a cumulative manner, to increasing concentrations (0.1 nM - 0.1 mM) of bimatoprost (dissolved in ethanol). In quiescent vessels, results were expressed in percent of 100 mM KCl-induced contraction. In endothelin-1-pre-contracted vessels, results were expressed in percent of the maximal contraction induced by endothelin-1. In KCl-pre-contracted vessels, results were expressed in percent of the plateau contraction reached 30 minutes after 100 mM KCl application. RESULTS Bimatoprost induced a significant (p < 0.05 - 0.001) vasoconstriction at concentrations equal to or higher than 0.1 micro M in quiescent vessels (0.1 mM: 73 +/- 12 %). In KCl-pre-contracted vessels, at concentrations higher than 1 micro M, bimatoprost induced significant (p < 0.05 - 0.01) contractions (0.1 mM: 67 +/- 17 %). In endothelin-1-pre-contracted vessels, bimatoprost also induced significant (p < 0.05 - 0.001) contractions at concentrations above 10 micro M (0.1 mM: 17 +/- 8 %). CONCLUSIONS The present study indicates that bimatoprost appears to have, in vitro, some vasoactive properties in porcine Ciliary Arteries. The question whether Lumigan has an influence on ocular blood flow needs to be further investigated.
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Absence of vasoactive properties of travoprost in isolated porcine Ciliary Arteries.
Klinische Monatsblatter fur Augenheilkunde, 2003Co-Authors: Reto Allemann, Josef Flammer, Ivan O HaefligerAbstract:Background: Ocular blood flow dysregulation is considered to be a risk factor associated with the optic neuropathy observed in glaucoma patients. The present study evaluates the vasoactive effect of the ocular hypotensive agent travoprost (Travatan®) on isolated pig Ciliary Arteries. Material and methods: Isometric forces were measured with a myograph system. Quiescent vessels were exposed in a cumulative manner to increasing concentrations (0.1 nM-0.1 mM) of travoprost ([+]-fluprostenol). Vessels pre-contracted with 100mM potassium chloride (KC1) or 10 nM endothelin-1 were also exposed in a similar manner to travoprost. Time-control experiments without travoprost were always run in parallel. In quiescent vessels, contractions were expressed in percent of 100 mM KC1-induced contractions. In vessels pre-contracted with endothelin-1, relaxations were expressed in percent of the maximal contraction induced by this peptide, while in those pre-contracted with KC1, relaxations were expressed in percent of the plateau-contraction reached 30 minutes after the application of this drug. Results: In quiescent vessels, travoprost had no statistically significant vasoconstrictive effect. In KC1- or in endothelin-1 pre-contracted vessels, travoprost had no statistically significant vasorelaxing effect. Conclusions: Although the clinical relevance of the results of this study for patients treated with travoprost (Travatan®) needs to be further investigated, travoprost appears to have no vasoconstrictive properties in isolated porcine Ciliary Arteries.
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the β blocker carteolol inhibits contractions induced by kcl in pig Ciliary Arteries an effect modulated by extracellular ca
Klinische Monatsblatter Fur Augenheilkunde, 2002Co-Authors: Giovanni Brogiolo, Josef Flammer, Ivan O HaefligerAbstract:BACKGROUND: To assess if the vasorelaxing properties of the ocular hypotensive beta-blocker carteolol could share some pharmacological features of calcium-channel antagonists in isolated porcine Ciliary Arteries. METHODS: In a myograph system (isometric force measurement), quiescent vessels were contracted with increasing concentrations of potassium chloride (KCl: 4.7 - 30 mM) in the presence of different concentrations of extracellular calcium (Ca (++): 0 - 10 mM) and/or carteolol (0 - 1 mM). Vessels precontracted with 20 mM KCl were exposed (cumulative manner) to carteolol (0.03 - 3 mM) in the presence of different concentrations of Ca (++) (0.25, 2.5, 10 mM). Contractions and relaxations are expressed in percent of 100 mM and 20 mM KCl-induced contractions, respectively (mean +/- SEM). RESULTS: Contractions induced by 30 mM KCl (99.0 +/- 4.8 %) were abolished in the absence of Ca (++) and markedly inhibited in the presence of carteolol (1 mM: 40.6 +/- 4.0 %). The inhibitory effect of carteolol on KCl-induced contractions was potentiated (0.25 mM: 6 +/- 2 %) by decreasing and reversed (10 mM: 94 +/- 5 %) by increasing Ca (++) concentrations. Vessels precontracted with KCl were relaxed by carteolol (maximum: 82 +/- 9 %), an effect potentiated (102 +/- 10 %) by lowering or inhibited (27 +/- 11 %) by increasing Ca (++) concentrations. DISCUSSION: The present in vitro pharmacological study, for which in principle no clinical interpretation should be made, suggests that carteolol shares, at rather high concentrations, some characteristics that apparently could mimic certain effects of calcium-channel blockers.
Kyoko Ohnomatsui - One of the best experts on this subject based on the ideXlab platform.
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possible connection of short posterior Ciliary Arteries to choroidal neovascularisations in eyes with pathologic myopia
British Journal of Ophthalmology, 2019Co-Authors: Tomoka Ishida, Takashi Watanabe, Tae Yokoi, Kosei Shinohara, Kyoko OhnomatsuiAbstract:Purpose To determine the connection between myopic choroidal neovascularisations (CNVs) and intrascleral vessels examined by swept-source optical coherence tomography (OCT). Methods The data of 124 eyes of 112 consecutive patients with myopic CNVs were retrospectively analysed. A myopic CNV was defined as a CNV occurring in eyes with pathologic myopia based on the META-PM study classification. The images obtained by swept-source OCT were analysed to determine the relationship between perforating scleral vessels and CNVs. The continuity of the scleral vessels and the CNV was also analysed. The OCT angiographic (OCTA) characteristics of the myopic CNVs at the active, scar and atrophic phases were also analysed. Results OCTA images showed that CNVs had blood flow in the active, scar and atrophic phases. Scleral perforating vessels were detected just below or around the CNV in 93 eyes (75%). In 10 of the 93 eyes, the scleral vessels and CNV appeared to be continuous through a defect of Bruch’s membrane in the OCT images. Indocyanine green angiography showed that these perforating vessels were intrascleral Arteries originating from the short posterior Ciliary Arteries (SPCAs). Conclusions Swept-source OCT showed that some of the myopic CNVs were continuous with scleral vessels mainly the SPCA. Further studies to confirm angiographical continuity between these two components are necessary.
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zinn haller arterial ring observed by icg angiography in high myopia
British Journal of Ophthalmology, 1998Co-Authors: Kyoko Ohnomatsui, Soh Futagami, Satoshi Yamashita, Takashi TokoroAbstract:AIMS To delineate the entire Zinn–Haller arterial ring angiographically in vivo. METHODS 382 highly myopic eyes (210 patients) with refractive errors greater than −8.25 D were examined using indocyanine green (ICG) videoangiography. A control group of 80 eyes (40 patients) had refractive errors within plano +/− 3 D. RESULTS The Zinn–Haller ring was visible in 206 of 382 highly myopic eyes (53.9%) by ICG angiography. Although only a part of the Zinn–Haller ring was visible in 162 of 206 eyes, in the remaining 44 eyes it was observed almost completely around the optic nerve head. No anastomotic channels between lateral and medial short posterior Ciliary Arteries were filled by ICG angiography. In 22 of the 44 eyes (50.0%) the Zinn–Haller ring was supplied by branches of the lateral and medial short posterior Ciliary Arteries; in seven eyes, it was supplied only by the lateral short posterior Ciliary artery; and in seven eyes, it was supplied only by the medial short posterior Ciliary artery. In none of the control subjects was the Zinn–Haller ring visible by ICG angiography. CONCLUSIONS The Zinn–Haller ring observed by ICG angiography was not a complete collateral circle between lateral and medial posterior Ciliary Arteries. Also, the patterns in supply vessels to the Zinn–Haller ring varied. ICG angiography made possible the detailed observation of the Zinn–Haller ring in human eyes in vivo.
Soh Futagami - One of the best experts on this subject based on the ideXlab platform.
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Zinn–Haller arterial ring observed by ICG angiography in high myopia
British Journal of Ophthalmology, 1998Co-Authors: Kyoko Ohno-matsui, Soh Futagami, Satoshi Yamashita, Takashi TokoroAbstract:AIMS To delineate the entire Zinn–Haller arterial ring angiographically in vivo. METHODS 382 highly myopic eyes (210 patients) with refractive errors greater than −8.25 D were examined using indocyanine green (ICG) videoangiography. A control group of 80 eyes (40 patients) had refractive errors within plano +/− 3 D. RESULTS The Zinn–Haller ring was visible in 206 of 382 highly myopic eyes (53.9%) by ICG angiography. Although only a part of the Zinn–Haller ring was visible in 162 of 206 eyes, in the remaining 44 eyes it was observed almost completely around the optic nerve head. No anastomotic channels between lateral and medial short posterior Ciliary Arteries were filled by ICG angiography. In 22 of the 44 eyes (50.0%) the Zinn–Haller ring was supplied by branches of the lateral and medial short posterior Ciliary Arteries; in seven eyes, it was supplied only by the lateral short posterior Ciliary artery; and in seven eyes, it was supplied only by the medial short posterior Ciliary artery. In none of the control subjects was the Zinn–Haller ring visible by ICG angiography. CONCLUSIONS The Zinn–Haller ring observed by ICG angiography was not a complete collateral circle between lateral and medial posterior Ciliary Arteries. Also, the patterns in supply vessels to the Zinn–Haller ring varied. ICG angiography made possible the detailed observation of the Zinn–Haller ring in human eyes in vivo.
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zinn haller arterial ring observed by icg angiography in high myopia
British Journal of Ophthalmology, 1998Co-Authors: Kyoko Ohnomatsui, Soh Futagami, Satoshi Yamashita, Takashi TokoroAbstract:AIMS To delineate the entire Zinn–Haller arterial ring angiographically in vivo. METHODS 382 highly myopic eyes (210 patients) with refractive errors greater than −8.25 D were examined using indocyanine green (ICG) videoangiography. A control group of 80 eyes (40 patients) had refractive errors within plano +/− 3 D. RESULTS The Zinn–Haller ring was visible in 206 of 382 highly myopic eyes (53.9%) by ICG angiography. Although only a part of the Zinn–Haller ring was visible in 162 of 206 eyes, in the remaining 44 eyes it was observed almost completely around the optic nerve head. No anastomotic channels between lateral and medial short posterior Ciliary Arteries were filled by ICG angiography. In 22 of the 44 eyes (50.0%) the Zinn–Haller ring was supplied by branches of the lateral and medial short posterior Ciliary Arteries; in seven eyes, it was supplied only by the lateral short posterior Ciliary artery; and in seven eyes, it was supplied only by the medial short posterior Ciliary artery. In none of the control subjects was the Zinn–Haller ring visible by ICG angiography. CONCLUSIONS The Zinn–Haller ring observed by ICG angiography was not a complete collateral circle between lateral and medial posterior Ciliary Arteries. Also, the patterns in supply vessels to the Zinn–Haller ring varied. ICG angiography made possible the detailed observation of the Zinn–Haller ring in human eyes in vivo.