Mucormycosis (phycomycosis) is a fungal infection that occurs in diabetic acidotic patients as well as normal individuals. The organism invades the walls of blood vessels to cause thrombosis. It primarily involves the sinuses, but can spread to the orbit and cavernous sinus resulting in decreased vision and ocular motility. Silver stains of biopsied tissue reveal the organism surrounding and involving the vessel wall. Back to Optic Nerve