Choroidal Nevus

What is Choroidal Nevus?

A choroidal nevus (plural: nevi) is typically a darkly pigmented lesion found in the back of the eye. It is similar to a freckle or mole found on the skin and arises from the pigment-containing cells in the choroid, the layer of the eye just under the white outer wall (sclera). (Figures 1 and 2).


Retinal artery occlusion occurs due to blockage of the retinal artery, often by an embolus (a small piece of cholesterol that blocks blood flow) or thrombus (blood clot). The retinal artery occlusion may be transient and last for only a few seconds or minutes if the blockage breaks up and restores blood flow to the retina, or it may be permanent.


Most commonly, a choroidal nevus does not cause any symptoms and is found on routine eye exam. However, sometimes nevi under the center of the retina (the macula) can cause blurred vision. When a nevus causes degeneration or dysfunction of the overlying RPE, fluid may accumulate under the retina or abnormal blood vessels (choroidal neovascularization) may develop and bleed or leak fluid.