Objective To observe the clinical characteristics of idiopathic retinal vasculitis aneurvsms,and neuroretinitis (IRVAN) syndrome,and to explore the optimum treatment timing. Methods The clinical data of 5 patients with IRVAN syndrome which were diagnosed by systemic examination,anterior segment,fundus photography and fundus fluorescein angiography (FFA) were retrospectively analyzed.According to the clinical characteristics,the course was divided into five stages.Six eyes were treated with panretianl laser photocoagulation,4 eyes treated with vitrectomy and panretinal laser photocoagulation. Results Idiopathic retinal vasculitis,multiple posterior retinal arterial aneurysms,neuroretinitis,retinal vascular occlusion and capillary nonperfusion were seen in all of the 10 eyes.Among them,4 eyes had vitreous haemorrhage,2 eyes had neovascularization in disk,1 eye had non-perfusion area in the macular,4 eyes had reached stage Ⅱ,and 6 eyes had reached stage Ⅲ.After treatment,4 eyes had maintained ≥0.6 vision,1 eye had 0.1-0.6 vision,and 5 eyes had ≤0.1 vision at the time of last follow-up. Conclusions Initiating panretinal laser photocoagulation at stage Ⅱ,which before (or shortly after) the development of any neovascularization might reduce the likelihood of disease progression.