[Segmental retinal arteritis and retinochorioiditis].

Acute ocular toxoplasmosis is characterized by a focal retinochoroidal infiltrate, often appearing in the immediate vicinity of an old retinochoroidal scar (satellite lesion). There are atypical forms of ocular toxoplasmosis, including retinal granulomas, intraretinal and subretinal neovascularization, preretinal gliosis and retinal detachment. In rare instances, associated immunological phenomena, i.e. concomitant vasculitis and perivasculitis, have been described. We report on a 28-year-old male patient presenting with signs of congenital toxoplasmosis with intracerebral calcifications and internal hydrocephalus (Whytt's disease). Ocular manifestations included an acute retinochoroidal infiltrate adjacent to a retinochoroidal scar and segmental retinal periarteritis. All arterioles were involved, but there was no inflammation of the venules. Fluorescein angiography revealed filling irregularities of the vessel segments involved. Like a tubercular patient with segmental periarteritis reported on as long ago as 1939, our patient had undergone treatment for active tuberculosis of the lung 6 years earlier. Considering the fact that segmental periarteritis without concomitant periphlebitis is very rarely seen, the coincidence of acute toxoplasmosis and previous tuberculosis suggests a complex immunological etiology of retinal vasculitis. This assumption may be supported by the fact that a combined systemic treatment with pyrimethamine, trimethoprim, sulfamethoxazole and prednisolone reduced the retinochoroidal inflammation and periarterial infiltrates.