Optic nerve coloboma and pit. A, Fundus photograph of the right eye shows a colobomatous defect in the inferonasal optic nerve (arrow). B, Photomicrograph shows gliotic, disorganized retina (asterisk) that prolapses into the optic nerve head defect, which is lined by excavated sclera. Normal retina, retinal pigment epithelium, and choroid terminate at the edge of the colobomatous defect (between arrows). C, Fundus photograph (right eye, different patient) shows an optic pit (arrowhead) with associated macular edema (arrow). D, Optical coherence tomography image from the same patient shows an optic pit–associated maculopathy with intraretinal cystoid edema and subretinal fluid.