· Background:Multifocal chorioretinitis with panuveitis (MCP) is a chronic inflammatory disease of the peripheral retina and choroid with typical clinical appearance. Although obvious involvement of the anterior segment is often mild, severe chronic inflammatory reactions can occur after cataract surgery. Explantation of an intraocular lens (IOL) or primary aphakia may be necessary. In this pilot study we therefore examined the iris of patients with MCP by means of fluorescein angiography (IAG) to investigate iris vessel involvement.· Materials und methods:Twenty-one eyes of 13 patients with MCP (12 women, 1 man) were examined by IAG. The average age of the patients was 72.5±6.2 years, and the average duration of the disease prior to examination was 13 months. In 9 of 21 eyes a pars plana vitrectomy (PPV) was performed because of marked vitreous opacification. IAG was performed before and after surgery. · Results: Although clinically unremarkable the iris of 14/21 eyes showed avascular zones in IAG; 13/21 had irregular vessels such as vascular collaterals, and 10/21 exhibited neovascularization. All eyes showed leakage of dye at the pupillary margin, and in 15/21 there was leakage out of peripheral iris vessels. In 2 of 9 eyes angiographic changes such as avascular zones regressed after PPV. · Conclusion: Irides in patients with MCP that are unremarkable on slit-lamp examination may show marked angiographic changes. Thus IAG in those cases with planned cataract extraction and IOL, if necessary combined with PPV for vitreous opacification, may be warranted in order to better assess the prognosis after surgery.