Purpose: Although much known about the optic disc shape and retinal nerve fiber layer in the course of glaucoma, there are no any data in literature that objectively evaluate the thickness of retrobulber optic nerve. This study quantitatively assessed the computed tomographic width of retrobulbar optic nerve-sheath complex in glaucomatous eyes and evaluated whether it was correlated with cup/disc ratio. Methods: Sixty-six eyes of 33 pa- Purpose: Although much known about the optic disc shape and retinal nerve fiber layer in the course of glaucoma, there are no any data in literature that objectively evaluate the thickness of retrobulber optic nerve. This study quantitatively assessed the computed tomographic width of retrobulbar optic nerve -sheath complex in glaucomatous eyes and evaluated whether it was correlated with cup / disc ratio. Methods: Sixty-six eyes of 33 pa-