A coloboma is a defect in the eye due to incomplete closure of the embryonic fissure, resulting in a gap or hole in the ocular structure. It is a congenital condition that may affect the eyelid, retina, choroid and optic nerve.

The symptoms depend on the location of the coloboma and ocular structures involved.

The chorioretinal coloboma is usually located inferonasally and may extend and involve the macula. It appears as a yellow-white lesion with pigmented margins, varying in size, and can be unilateral or bilateral. This coloboma increases the risk of retinal detachment, and choroidal neovascularization on its margins.