Uveal Melanoma - Symptoms, Causes, Treatment & Prevention

```html

Overview

Uveal melanoma (UM) is a rare, malignant tumor that arises from the melanocytes (pigment‑producing cells) within the uveal tract of the eye. The uveal tract consists of three structures: the choroid (the most common site), the ciliary body, and the iris. Unlike cutaneous melanoma, which originates in the skin, uveal melanoma develops inside the eye and can spread (metastasize) to other organs, most often the liver.

Who it affects: Most cases occur in adults between the ages of 50 and 70, and the disease is about three times more common in men than women. The incidence is higher among people of Caucasian ancestry and those with lighter eye colors (blue, gray, or green).<sup>[1] Mayo Clinic</sup>

Prevalence: In the United States, approximately 2,500 new cases of uveal melanoma are diagnosed each year, representing roughly 5% of all melanomas and less than 1% of all eye cancers.<sup>[2] SEER Cancer Statistics Review</sup> The worldwide incidence ranges from 4 to 7 cases per million people per year.<sup>[3] WHO</sup>

Symptoms

Uveal melanoma frequently develops without obvious symptoms, especially when the tumor is small. When symptoms do occur, they may include:

• Floaters: Small, shadow‑like specks that move across the visual field.
• Blurred or Decreased Vision: May affect one eye more than the other.
• Loss of Peripheral Vision: Particularly if the tumor is located near the edge of the retina.
• Change in the Appearance of the Eye: A visible dark spot on the iris (iris melanoma) or a subtle bulge in the sclera.
• Eye Pain or Redness: Rare, but can occur if the tumor causes secondary inflammation.
• Photopsia (Flashing Lights): Brief flashes of light, often described as "sparkles."
• Eye Irritation or Dryness: Secondary to tumor‑induced changes in tear production.

Because many of these signs can mimic benign eye conditions (e.g., vitreous floaters, age‑related macular degeneration), routine dilated eye examinations are essential for early detection.

Causes and Risk Factors

What Causes Uveal Melanoma?

The exact trigger is unknown, but UM arises from genetic mutations within melanocytes of the uveal tract. Common molecular alterations include:

• Mutations in the GNAQ or GNA11 genes (found in ~80% of cases).
• Chromosomal abnormalities, especially loss of chromosome 3 (monosomy 3) and gain of chromosome 8q, which are linked with a higher risk of metastasis.
• Alterations in the BAP1 tumor‑suppressor gene, associated with aggressive disease.

These genetic changes are somatic (acquired) rather than inherited, meaning they develop during a person’s lifetime.

Risk Factors

• Age: Risk increases after age 50.
• Sex: Men are diagnosed more often than women.
• Race/Ethnicity: Highest in people of European descent; rare in African, Asian, and Hispanic populations.
• Eye Color: Light-colored eyes (blue/gray/green) carry a higher risk.
• Family History of Uveal Melanoma: Very uncommon, but a small hereditary component exists.
• Pre‑existing Ocular Conditions: Presence of choroidal nevi (benign pigmented lesions) that enlarge over time can transform into melanoma.
• Ultraviolet (UV) Light Exposure: Unlike cutaneous melanoma, the link between UV exposure and UM is weak and remains controversial.<sup>[4] NIH</sup>

Diagnosis

Prompt and accurate diagnosis requires a combination of clinical examination, imaging, and sometimes tissue sampling.

Eye Examination

• Dilated Fundus Examination: Using special lenses, an ophthalmologist inspects the back of the eye for pigmented lesions.
• Indirect Ophthalmoscopy: Provides a wide view of the retina and choroid.

Imaging Studies

• Ultrasound (A‑scan & B‑scan): Measures tumor thickness and internal reflectivity; a characteristic “acoustic hollowness” suggests melanoma.
• Optical Coherence Tomography (OCT): Offers high‑resolution cross‑sectional images of retinal layers.
• Fundus Fluorescein Angiography (FFA): Highlights abnormal blood vessels within the tumor.
• Magnetic Resonance Imaging (MRI): Useful for assessing extra‑ocular extension and for planning radiation therapy.

Biopsy (Rarely Needed)

Fine‑needle aspiration biopsy (FNAB) may be performed when the diagnosis is uncertain or when molecular testing is required for prognosis. The procedure carries a small risk of tumor seeding and is therefore reserved for selected cases.

Staging

Once a melanoma is confirmed, staging follows the American Joint Committee on Cancer (AJCC) criteria, which consider tumor size, location (choroidal vs. ciliary body vs. iris), and presence of systemic spread.

Treatment Options

Treatment aims to eradicate the primary tumor while preserving vision whenever possible. The choice of therapy depends on tumor size, location, patient age, overall health, and personal preferences.

Local Therapies

• Plaque Brachytherapy: A small, radioactive disc (typically Iodine‑125, Ruthenium‑106, or Palladium‑103) is sutured to the sclera over the tumor for 3–7 days. It delivers a high radiation dose directly to the lesion with minimal exposure to surrounding tissue. Success rates (local control) exceed 90% for tumors ≤ 10 mm thickness.<sup>[5] Cleveland Clinic</sup>
• External Beam Radiation Therapy (EBRT): Includes proton beam therapy and stereotactic radiosurgery (Gamma Knife, CyberKnife). Preferred for tumors near the optic nerve or iris where plaque placement is difficult.
• Transpupillary Thermotherapy (TTT): Uses infrared laser to heat and destroy small (< 3 mm) tumors. Often combined with brachytherapy.
• Enucleation: Surgical removal of the eye. Reserved for very large tumors, those causing painful blind eye, or when other treatments are not feasible. Modern prosthetic rehabilitation offers good cosmetic outcomes.

Systemic Therapies (Metastatic Disease)

Once uveal melanoma spreads—most often to the liver—systemic options become necessary. Traditional melanoma drugs (e.g., BRAF inhibitors) are largely ineffective because UM rarely harbors BRAF mutations.

• Immune Checkpoint Inhibitors: Nivolumab or pembrolizumab (PD‑1 blockers) have modest activity; response rates ~5‑10%.<sup>[6] JAMA Ophthalmology 2022</sup>
• MEK Inhibitors: Selumetinib showed early promise but failed to improve overall survival in phase III trials.
• Liver‑Directed Therapies: Hepatic perfusion, radiofrequency ablation, or yttrium‑90 radioembolization can control liver metastases.
• Clinical Trials: Emerging agents targeting the GNAQ/GNA11 pathway, bispecific antibodies, and adoptive T‑cell therapies are under investigation.

Supportive & Lifestyle Measures

• Regular ophthalmic follow‑up (every 3–6 months) to monitor for local recurrence.
• Low‑fat diet and avoidance of excessive alcohol to support liver health, especially if hepatic metastasis is present.
• Psychological support—counseling or support groups—for coping with vision loss or cancer‑related anxiety.

Living with Uveal Melanoma

Daily Management Tips

• Adopt a Structured Follow‑up Schedule: After treatment, most specialists recommend eye examinations every 3–4 months for the first 2 years, then every 6 months up to 5 years, and annually thereafter.
• Protect Your Eyes: Wear UV‑blocking sunglasses (UV‑400) to reduce photic stress, even though UV is not a proven cause, it helps overall ocular health.
• Monitor Vision Changes: Keep a simple diary of any new floaters, blurriness, or visual field loss and report promptly.
• Maintain Liver Surveillance: Blood tests (LFTs, LDH) and imaging (MRI or ultrasound) every 6–12 months help detect early liver metastasis.
• Healthy Lifestyle: Balanced diet rich in fruits, vegetables, whole grains; regular physical activity (150 min/week moderate intensity); adequate sleep; stress‑reduction techniques (mindfulness, yoga).
• Eye Prosthesis Care (if enucleated): Clean the orbital implant daily with mild soap and follow the prosthetist’s instructions to avoid infection.
• Seek Vision Rehabilitation Services: Low‑vision aids, contrast‑enhancing glasses, and occupational therapy can improve quality of life when vision is compromised.

Prevention

Because most risk factors (age, genetics, eye color) cannot be modified, prevention focuses on early detection and general eye health:

• Schedule a comprehensive dilated eye exam at least once every two years after age 40, and annually after age 60.
• Report any new or changing pigmented spots (nevus) in the eye to an ophthalmologist.
• Wear sunglasses with 100% UVA/UVB protection whenever outdoors.
• Manage systemic health—control diabetes, hypertension, and cholesterol—to support overall vascular health of the eye.
• Consider genetic counseling only if there is a strong family history of uveal or other melanomas.

Complications

If left untreated or if the disease progresses, several serious complications can arise:

• Vision Loss: Tumor growth may involve the macula or optic nerve, leading to permanent blindness in the affected eye.
• Eye Pain & Secondary Glaucoma: Tumor invasion can obstruct aqueous outflow, raising intra‑ocular pressure.
• Retinal Detachment: Large tumors may cause traction on the retina.
• Metastatic Spread: Approximately 50% of patients develop metastases, most commonly to the liver; median survival after metastasis is 12–15 months.<sup>[7] American Cancer Society</sup>
• Enucleation‑Related Issues: Orbital implant exposure, socket contracture, or prosthetic discomfort.

When to Seek Emergency Care

References

1. Mayo Clinic. “Uveal (Eye) Melanoma.” 2023. https://www.mayoclinic.org/
2. SEER Cancer Statistics Review, National Cancer Institute, 2022.
3. World Health Organization. “Cancer Fact Sheets.” 2022.
4. National Institutes of Health, National Cancer Institute. “Uveal Melanoma Treatment (PDQ®) – Health Professional Version.” 2024.
5. Cleveland Clinic. “Plaque Brachytherapy for Eye Melanoma.” 2023.
6. JAMA Ophthalmology. “Efficacy of Immune Checkpoint Inhibitors in Metastatic Uveal Melanoma.” 2022;140(5):500‑508.
7. American Cancer Society. “Uveal Melanoma Overview.” 2024.

```