Choroidal Nevus vs. Choroidal Melanoma: What ‘We’ll Photograph It and Watch’ Really Means
Choroidal Nevus and Choroidal Melanoma at a Glance
Your eye doctor found a pigmented spot at the back of your eye and wants to track it with pictures. That plan is not vagueness, and it is not your doctor stalling. Ophthalmologists photograph a nevus and compare the pictures over time to see whether its size or shape changes, and a spot that stays unchanged over one to two years is unlikely to be a melanoma1. Stability over time is the single most useful piece of information about a pigmented spot, and no single test replaces it.
For most people the honest answer is: not very, and yes, keep the appointment. Choroidal nevi occur in about 5 of every 100 people in the United States, and transformation into melanoma happens at roughly 1 in 9,000 nevi per year2. Choroidal melanoma itself is rare, with an age-adjusted incidence of about 5.1 per million people per year3. The reason for monitoring is not that your spot is likely to be dangerous. It is that the small number that do change are far easier to treat when the change is caught early.
Book the follow-up your doctor recommended and put it in your calendar rather than leaving it to memory. Ask for a copy of the photograph so you know what is being compared. In the meantime, a freckle that has grown or changed shape or color, and any new eye pain, flashing lights or change in vision, should be checked1. You do not need to test your own vision daily or hunt for symptoms. Live normally, and call if something changes.
What a Choroidal Nevus Is
The choroid is a blood-vessel-rich layer sitting between your retina and the white wall of the eye. A nevus is a common pigmented growth made of melanocytes (melanocytes: the cells that make the pigment coloring hair, skin and eyes), and a choroidal nevus sits under the retina where it can only be seen during an eye exam1. It is the eye's version of a mole. Most have been there quietly for years, which is why hearing about one for the first time can feel more alarming than the finding itself is.
Common enough that finding one is an ordinary day in an eye clinic. About 5.6 of every 100 White individuals, 2.7 of every 100 Hispanic individuals and 0.6 of every 100 Black individuals in the United States have a choroidal nevus2. Estimates across the adult population range from roughly 5 to 25 of every 100 people, and these lesions carry only a small chance of turning malignant4. If your spot were automatically worrying, millions of people would be in treatment. They are not, and most never need any.
A flat nevus away from the center of your vision does nothing you can feel. Most choroidal nevi cause no symptoms and are found on a routine dilated eye exam2. One sitting under the macula (macula: the small central part of the retina you read with) can blur central vision, and degeneration of the pigment layer over a nevus can lead to fluid or abnormal new blood vessels2. Those are the situations that get attention. Feeling perfectly normal is exactly what most people with a nevus report.
What a Choroidal Melanoma Is
Choroidal melanoma arises from the same melanocytes that make up a nevus, but the cells divide and the lesion grows and thickens. Some do develop out of a pre-existing nevus, which is the whole reason nevi are watched: a pre-existing choroidal nevus is a recognized risk factor, with a transformation risk in the range of 1 in 5,000 to 1 in 8,845 per lesion, alongside light iris color, light skin and northern European ancestry3. Ultrasonography is the main test used to confirm it, and enhanced depth imaging optical coherence tomography shows shadowing of the choroid and subretinal fluid in almost all cases3. Diagnosis rarely needs a biopsy.
It is the most common cancer starting inside the adult eye, and it is still rare in absolute terms. Its age-adjusted incidence is about 5.1 per million people per year3. Put next to a nevus prevalence of roughly 5 of every 100 adults, the arithmetic is reassuring: the overwhelming majority of pigmented spots stay exactly what they are. Rarity is also why your doctor may send you to a specialist center. These are lesions that benefit from eyes that see many of them.
There is often nothing to notice, which is why monitoring exists. About 30 of every 100 people with choroidal melanoma have no symptoms at diagnosis, while about 38 of every 100 report decreased vision, about 9 of every 100 report flashes of light, about 7 of every 100 report floaters, about 6 of every 100 report loss of peripheral vision, and only about 2 of every 100 have eye pain3. Pain is a poor guide here. A change in what you can see is the more useful signal, and it is worth a prompt call rather than a wait.
Choroidal Nevus and Choroidal Melanoma Side by Side
Your doctor is comparing several features at once rather than looking for one giveaway. The table below sets out the general pattern. Read it as what raises or lowers suspicion, not as a checklist you can apply to your own photograph.
| Feature | More typical of a nevus | Raises suspicion of melanoma |
|---|---|---|
| Thickness on ultrasound | 2 mm or less | More than 2 mm5 |
| Fluid under the retina | None | Present on OCT5 |
| Orange pigment | Absent | Present on autofluorescence5 |
| Surrounding halo and drusen | Often present | Often absent4 |
Eye doctors use a short memory aid for the features that matter. The risk factors for a nevus turning into melanoma are thickness above 2 mm on ultrasound, subretinal fluid on optical coherence tomography, symptomatic vision loss to 20/50 or worse, orange pigment on autofluorescence, acoustic hollowness on ultrasound, and diameter above 5 mm on fundus photography5. Absence of a surrounding halo, absence of drusen over the lesion, and closeness to the optic nerve head add further suspicion4. Ask which of these your spot has. It is the most informative question you can put to your doctor.
The numbers below come from a large series at a specialist referral center, so they describe lesions selected because someone was already concerned. Across 2,355 nevi followed there, the mean 5-year risk of transformation was about 1 of every 100 with no risk factor, 11 with one, 22 with two, 34 with three, 51 with four and 55 with five5. A spot with none of those features sits at the bottom of that scale. If your doctor described your nevus as flat, dry, without orange pigment and unchanged, ask them to confirm which group it falls into.
| Warning features present | Mean 5-year chance of transformation |
|---|---|
| None | About 1 of every 1005 |
| One | About 11 of every 1005 |
| Two | About 22 of every 1005 |
| Three or more | About 34 of every 100 or higher5 |
What 'Watching It' Actually Involves
Monitoring is a set of painless imaging tests, repeated so the pictures can be laid side by side. Retinal photography tracks growth, and optical coherence tomography, ultrasound and fluorescein angiography are added for suspicious or larger lesions2. Optical coherence tomography is a light-based cross-section of the retina. Ultrasound measures thickness through a gel on your closed eyelid. Expect dilating drops, and expect blurry near vision and light sensitivity for a few hours, so arrange a ride.
The interval follows the risk rather than a fixed calendar. Follow-up is generally annual for an uncomplicated nevus, and about every 4 to 6 months when risk features are present2. Some patients are rechecked at six months, and a nevus unchanged over one to two years is unlikely to be a melanoma1. Intervals often lengthen once several visits show no change. Ask your doctor to tell you the interval and the reason for it, and ask what would shorten it.
Two things move a case from watching to acting: new warning features, and growth. Nevi without concerning features are simply observed, and assessments become more frequent as risk features accumulate4. Growth alone does not automatically mean cancer, and your doctor will weigh how fast, in what direction, and alongside which other features. If a referral to an ocular oncology service follows, that is the system working as intended rather than a signal that the news is bad.
If It Does Turn Out to Be a Melanoma
Losing the eye is most people's first fear, and for many tumors it is not the first option. Plaque brachytherapy is first-line treatment for medium-sized tumors, with proton beam radiation as another radiation option, and removal of the eye reserved for cases where growth continues4. Plaque brachytherapy means a small radioactive disc is placed on the outside wall of the eye over the tumor, typically for a few days, then removed. The eye stays in place.
This is the comparison that matters most, and it has been directly tested. In a randomized trial of 1,317 people with medium choroidal melanoma, all-cause death by 12 years was 43 of every 100 after iodine-125 plaque brachytherapy and 41 of every 100 after removal of the eye, and longer follow-up confirmed no survival difference between the two treatments6. Those are sobering figures, and they count deaths from every cause across twelve years of follow-up. The practical message is that choosing the eye-sparing option did not cost survival.
Treatment of the eye is followed by long-term checks of the rest of the body. Roughly half of people with uveal melanoma eventually develop spread, which involves the liver in about 93 of every 100 of those cases, gene expression profiling separates lower-risk class 1 tumors from class 2 tumors whose 5-year risk of spread is about 72 of every 100, and surveillance includes liver function testing twice yearly with annual liver imaging3. Ask whether your tumor was profiled, because the answer sets how closely you are followed.
Risks, Outlook, and Living With Being Watched
Most nevi do nothing for the rest of your life. The annual chance of transformation is roughly 1 in 9,000 nevi2, and among nevi with no warning features at a referral center the mean 5-year risk was about 1 of every 1005. No one can give you a personal guarantee, and no honest doctor will. What they can do is put your spot into a risk group and re-check it. For most readers, that group is the low one.
Outcomes depend heavily on tumor size, location and cell biology, so a page cannot forecast an individual course. In the randomized trial, death with confirmed melanoma spread was 10 of every 100 at 5 years and 21 of every 100 at 12 years after plaque brachytherapy, and 11 and 17 of every 100 after removal of the eye6. Ask your team what to expect for vision in the treated eye over time, and what is realistic for your tumor's size and position, rather than reading a population number as your own.
Being told you have something that needs watching is its own burden, and it is a common one. It helps to name the interval, hold the appointment, and stop researching between visits. Bring one written list of questions to each check. Ask your doctor to show you the comparison images so the words 'stable' and 'unchanged' have something visible behind them. If the worry is affecting sleep or daily life, say so, because that is a treatable problem too.
When to Call Your Eye Doctor and Who You Will See
Do not wait for your scheduled visit if something changes. New eye pain, flashing lights, or a change in vision, and any sense that a pigmented spot has grown or changed shape or color, should be checked1. Decreased vision, flashes, floaters and loss of side vision are the symptoms most often reported when a choroidal melanoma is found3. Many such calls end with an exam showing no change, which is a good outcome and not a wasted appointment.
An optometrist or general ophthalmologist often finds the spot and may do the routine photographs. A retina specialist takes over the detailed imaging when features are borderline. An ocular oncologist, a specialist in tumors of the eye, handles suspicious lesions and treatment. Ask who is holding your images so comparisons are made against the same baseline, and ask for copies if you move or change practices.
Common Questions About a Choroidal Nevus
No. A nevus is a benign pigmented growth, the eye's equivalent of a mole. These lesions are found in roughly 5 to 25 of every 100 adults and carry only a small chance of turning malignant4. The annual chance of transformation is roughly 1 in 9,0002. Your doctor is monitoring it for the same reason a dermatologist watches a mole: not because it is expected to change, but because change is easy to act on when it is caught early.
Because the imaging usually answers the question with less risk. Ultrasonography is the main confirmatory test for choroidal melanoma, and enhanced depth imaging optical coherence tomography shows characteristic changes in almost all cases3. A biopsy inside the eye carries its own risks. For borderline spots, comparing images over months is a more reliable answer than a single sample, which is exactly what 'photograph it and watch' is doing.
It means your doctor will look harder, not that you have cancer. Growth is weighed alongside the other features. Thickness above 2 mm, subretinal fluid, symptoms, orange pigment, acoustic hollowness and diameter above 5 mm are the features that raise concern5, and assessments become more frequent as those features accumulate4. Expect a shorter interval, extra imaging, or a referral. Ask specifically how much it grew and over what period.
It depends on your risk features. Follow-up is generally annual for an uncomplicated nevus, and about every 4 to 6 months when risk features are present2. A nevus that stays unchanged over one to two years is unlikely to be a melanoma1, and intervals often stretch out after several stable visits. Ask your doctor to name your interval and what would change it, and book the next appointment before you leave.
Usually not at all. Most choroidal nevi cause no symptoms and are found incidentally on a routine dilated exam2. A nevus under the macula can blur central vision, and degeneration of the pigment layer over a nevus can lead to fluid or abnormal new blood vessels, which are treated with injections into the eye2. If your reading vision is normal and your doctor has told you the spot is away from the center, it is unlikely to change how you see.
Not in the direct way most people assume. Nevi are formed by clumps of melanocytes and may have some association with ultraviolet light exposure, and people can be born with them or develop them later1. Having moles on your skin does not by itself make your eye spot more dangerous. The reported risk factors for choroidal melanoma are light iris color, light skin, northern European ancestry and a pre-existing choroidal nevus3. Sunglasses are sensible for your eyes generally, and they are not a treatment for a nevus.
More Questions About Melanoma, Treatment and Follow-Up
Often not. Plaque brachytherapy is the first-line treatment for medium-sized tumors, with proton beam radiation another option, and removal of the eye reserved for continued growth4. A randomized trial of 1,317 people found no survival difference between plaque brachytherapy and removal of the eye out to 12 years6. That result is why eye-sparing radiation became standard for medium tumors. Your options depend on the size and position of the tumor.
It is a reasonable thing to ask for, especially if your lesion has any of the warning features or has changed. Choroidal melanoma is rare, so experience is concentrated in ocular oncology services. Suspicious lesions and lesions that change during surveillance warrant subspecialist referral4. Bring your images or ask that they be sent, since a comparison against your own earlier photographs is worth more than a fresh look at one moment in time.
Not for a nevus that is being watched. That surveillance belongs to treated melanoma. After a uveal melanoma diagnosis, monitoring includes liver function testing twice yearly and annual liver imaging, because spread involves the liver in about 93 of every 100 cases that spread3. If you have only a nevus under observation, whole-body imaging is not part of the plan, and asking your doctor to confirm that in plain words is a fair use of your appointment.
- Which of the warning features does my nevus have, and which does it not?
- How thick is it, and how wide?
- Is there any fluid or orange pigment on my scans?
- What is my follow-up interval, and what would shorten it?
- Can I have a copy of the photograph and the measurements?
- Has it changed compared with my last visit, and by how much?
- At what point would you refer me to an ocular oncology service?
- Which symptoms should make me call before my next appointment?
- American Academy of Ophthalmology, EyeSmart patient information (2024). Nevus (Eye Freckle).
- American Society of Retina Specialists (2024). Choroidal Nevus (patient information).
- EyeWiki, American Academy of Ophthalmology (2025). Choroidal and Ciliary Body Melanoma (EyeWiki).
- EyeNet Magazine, American Academy of Ophthalmology (2023). Diagnosis and Management of Choroidal Melanoma.
- Retina 2019;39(10):1840-1851, retrospective cohort of consecutive choroidal nevi at a single ocular oncology referral centre (2019). Choroidal nevus imaging features in 3,806 cases and risk factors for transformation into melanoma in 2,355 cases: the 2020 Taylor R. Smith and Victor T. Curtin Lecture.
- Archives of Ophthalmology 2006;124(12):1684-1693, multicentre randomized controlled trial of 1,317 participants with medium-sized choroidal melanoma (2006). The COMS randomized trial of iodine 125 brachytherapy for choroidal melanoma, V: twelve-year mortality rates and prognostic factors (COMS Report No. 28).