Can optic nerve head drusen cause sudden unilateral loss of peripheral vision due to a spontaneous vascular event?

Disc Drusen. I am not aware of any association between optic nerve drusen and sudden unilateral vision loss from a vascular event. A vascular event should be evaluated and treated the same as if the disc drusen were not there.
No. Optic nerve head drusen do not cause vascular events. Loss of vision due a vascular event is a serious problem that may be a warning sign for a life-threatening problem. See an ophthalmologist asap.