Severe periphlebitis, peripheral retinal ischemia, and preretinal neovascularization in patients with multiple sclerosis.

Two patients with definite multiple sclerosis and marked retinal periphlebitis developed occlusive peripheral retinal vasculitis, which resulted in peripheral retinal ischemia and peripheral retinal neovascularization. Results of investigation for other causes of peripheral proliferative retinopathies were negative in both patients although one patient had a positive anticardiolipin antibody. Both patients have been followed up for over seven years and have maintained good visual acuity with mild regression of the preretinal neovascularization without laser intervention. An analysis of these two cases and six other reported cases indicates that severe periphlebitis can evolve into occlusive peripheral vasculitis, which results in peripheral retinal neovascularization in patients with multiple sclerosis.