Choroidal Nevus

Description

Like a raised freckle on the skin, nevi can also occur inside your eye. The most common "choroidal nevus" are unusual and can only be seen by an eye care specialist. Like a nevus on the skin, a choroidal nevus can grow into a malignant melanoma.

A benign appearing choroidal nevus.

A choroidal nevus rarely requires treatment. Photography is typically used to document the size of the choroidal nevus. If the choroidal nevus has orange pigmentation, if the nevus is leaking fluid, or has a thickness of 2 mm or more it may be (or become) a malignant choroidal melanoma.

Depending on its appearance, patients with a choroidal nevus should have their eyes examined (at least) every year. Only your doctor can look inside your eye to see if the choroidal nevus has changed. If the choroidal nevus has orange pigment or has thickened, it should be checked more often. If a choroidal nevus is leaking subretinal fluid, this is a particularly ominous sign. Such tumors should be followed most closely for evidence of growth or malignant transformation into a choroidal melanoma.

It is reasonable to have an eye cancer specialist check to see if your choroidal nevus looks suspicious. This examination may include the use of ultrasound, specialized photography or an intraocular angiogram. It is a good idea to keep a picture of your choroidal nevus. This picture can be compared to future examinations to help determine if the nevus has changed or stayed the same.

Symptoms

A benign choroidal nevus rarely causes symptoms. Rarely a choroidal nevus can leak fluid or be associated with the growth of abnormal blood vessels (neovascularization). These related changes can cause a localized retinal detachment/degeneration, flashing lights and loss of vision.

A typical choroidal nevus is asymptomatic or "causes no symptoms" and found by routine dilated eye examination with ophthalmoscopy.

Diagnosis

This movie demonstrates how a suspicious choroidal nevus can demonstrate focal leakage on fluorescein angiography.

Choroidal nevus is typically a pigmented tumor of the blood vessel layer (choroid) beneath the retina. A choroidal nevus is typically gray but can be brown, yellow or variably pigmented. Your eye care professional will look to see if the choroidal nevus is raised (has thickness), orange pigment (lipofuscin), or is leaking fluid (retinal detachment). If the choroidal nevus has one or more of these findings, it is labeled a suspicious choroidal nevus that might turn into (or be) a small choroidal melanoma.

A choroidal nevus can have yellow-white spots on its surface called drusen. This is a sign that the choroidal nevus is preventing the eye from removing retinal waste products. It is also a sign that the choroidal nevus has been present for enough time for those products to accumulate. There are no studies that show how long it takes for drusen to form on a choroidal nevus.

Treatments

A benign choroidal nevus requires no treatment and there is no way to safely remove them. Since a choroidal nevus can turn into a choroidal melanoma, it is reasonable to have it periodically observed by your eye care professional.

A suspicious choroidal nevus with a ring of orange pigmentation. One year later, serial observation revealed resolution of most of the orange pigmentation.

Additional info

Dr. Finger believes that since skin and conjunctival melanomas have been linked to ultraviolet exposure, and since choroidal melanomas are more commonly found in patients with blue eyes, outdoor occupations, and in Australia (where there is an ozone hole); it is reasonable to wear ultraviolet (UV) blocking sunglasses. Dr. Finger says, "Think of sunglasses as sun block for your eyes."TM

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