Abstract
Paranasal sinus disease can cause a condition that mimics optic neuritis. Simultaneous appearance of both diseases would create etiological dilemma. We report two cases of retrobulbar optic neuropathy secondary to isolated sphenoid sinus disease. In the case of a 65-year-old female who had presented with acute loss of vision in the left eye associated with left-sided frontal headache which subsequently turned out to be caused by optic nerve compression at the orbital apex due to collection in abnormally pneumatized left lesser wing of the sphenoid. In another case, a 65-year-old lady had presented with symptoms of bilateral retrobulbar optic neuropathy which was found to be due to direct compression of optic nerves at the orbital apex secondary to metastases from breast carcinoma.