Fundus photograph of the left eye before and after vitreous surgery. (A) Retinal detachment and retinal schisis can be seen with a double ring apparatus. Glial tissue can be seen at the optic pit (arrow). (B) Fundus photograph of the left eye four years after vitreous surgery. Retinal detachment and retinoschisis are absent and the excavation of the optic disc is clearly seen after removal of the glial tissue (arrow).