Unilateral Vision Loss Due to Isolated Onodi Cell Mucocele

Onodi cell mucocele is a rare, benign, cystic, destructive and expansive lesion. While the sphenoid sinus mucocele is 1% to 2%, onodi cell mucocele is very rare. Because of its direct mass compression effect, its proximity to the orbital apex may cause many symptoms such as loss of vision, eye movements, and exophthalmus. Imaging methods have an important priority in diagnosis. It also plays a crucial role in planning treatment quickly and guiding the surgeon. Surgical excision is performed in the treatment, usually with an endonasal approach.