Objective:To report the clinical and fluorescein angiography features of arteriovenous(AV)malformation of the iris.Patients and Methods:We reviewed the medical records and photographs of our patients with iris AV malformation.The iris lesion was classified as simple if the blood vessel made a loop only and complex if it made intertwining convolutions.We reviewed systemic and ocular findings in each case.Results:Fourteen patients had an iris AV malformation.The mean age at diagnosis was 49 years(median age,50 years;range,16-79 years).All lesions were unilateral,without predilection for either eye or significant systemic associations.The lesion was classified as simple in 5 cases and complex in 9.The full extent of the lesion was not easily visualized with routine slitlamp examination.However,it was apparent with fluorescein angiography,which showed the vascular lesions to be uniformly hyperfluorescent in the early phases,with minimal or no late leakage of dye.There were typical areas of capillary nonperfusion in the iris stroma between the large abnormal vessels.A dilated episcleral blood vessel(“ sentinel vessel“)was noted in the quadrant of the iris lesion in 7(50%)of the 14 cases.On follow-up ranging from 6 months to 14 years,none of the lesions changed or produced complications.Conclusions:Iris AV malformation has characteristic clinical and fluorescein angiographic features.It appears to be a benign stationary condition that has no apparent systemic associations and no local complications. Objective: To report the clinical and fluorescein angiography features of arteriovenous (AV) malformation of the iris. Patients and Methods: We reviewed the medical records and photographs of our patients with iris AV malformation. Iris lesion was classified as simple if the blood vessel. made a loop only and complex if it made intertwining convolutions.We made systemic and ocular findings in each case. Results: Fourteen patients had an iris AV malformation. The mean age at diagnosis was 49 years (median age, 50 years; range, 16 -79 years) .All lesions were unilateral, without predilection for either eye or significant systemic associations. The lesion was classified as simple in 5 cases and complex in 9.The full extent of the lesion was not easily visualized with routine slitlamp examination .Hever , it was apparent with fluorescein angiography, which showed the vascular lesions to be uniformly hyperfluorescent in the early phases, with minimal or no late leakage of dye. There were typical areas of capillary nonperfusion in the iris stroma between the large irregular vessels. A dilated episcleral blood vessel (”sentinel vessel") was noted in the quadrant of the iris lesion in 7 (50%) of the 14 cases. On follow-up ranging from 6 months to 14 years, none of the lesions changed or produced complications. Conclusions: Iris AV malformation has characteristic clinical and fluorescein angiographic features. It appears that there is no apparent systemic associations and no local complications.