Unveiling Choroidal Melanoma: Insights & Treatments

Choroidal melanoma is a rare but significant form of eye cancer that originates in the choroid, the layer of blood vessels and connective tissue beneath the retina.

While it accounts for only 5% of all melanomas, it is the most common primary intraocular malignancy in adults.

Choroidal melanoma has a significant impact on health due to its potential to cause vision loss, eye damage, and even metastasis to other organs.

The essential function affected by choroidal melanoma is vision, as the tumor can grow and damage the delicate structures of the eye.

In the short term, untreated choroidal melanoma can lead to visual disturbances and eventual blindness, while in the long term, it can spread to other parts of the body, leading to a poor prognosis.

One of the challenges of choroidal melanoma is its asymptomatic nature in the early stages, emphasizing the importance of early detection through regular eye screenings to improve outcomes.

Causes of Choroidal Melanoma

The causes of choroidal melanoma are not entirely clear, but several factors have been identified as potential contributors to its development.

• Genetic predisposition can play a significant role in the development of choroidal melanoma. Mutations in certain genes, such as the BAP1 gene, have been associated with an increased risk of developing this type of cancer. These genetic changes can lead to uncontrolled cell growth and tumor formation in the choroid over time.
• Excessive exposure to ultraviolet (UV) radiation, particularly UV-B rays, is another major cause of choroidal melanoma. Prolonged exposure to sunlight or artificial UV sources can damage the DNA in ocular cells, triggering mutations that can eventually lead to cancerous growth in the choroid.
• Aging is a significant risk factor for choroidal melanoma, with the majority of cases diagnosed in individuals over the age of 50. As the eye ages, cellular changes and accumulated damage increase the susceptibility to developing cancerous growths in the choroid.
• Ocular melanocytosis, a condition characterized by an increased number of melanocytes in the eye, is considered a risk factor for choroidal melanoma. Individuals with ocular melanocytosis have a higher likelihood of developing this type of eye cancer due to the presence of abnormal melanocytes in the choroid.

In addition to these primary causes, several secondary risk factors and lifestyle contributors can also influence the development of choroidal melanoma.

• Smoking is a significant lifestyle factor that can increase the risk of choroidal melanoma. The harmful chemicals in tobacco smoke can promote cellular damage and inflammation in the eye, creating an environment conducive to tumor formation.
• Occupational exposure to certain chemicals or toxins, such as those found in certain industries like welding or chemical manufacturing, can also elevate the risk of developing choroidal melanoma. Prolonged exposure to these substances can trigger cellular changes that predispose the eye to cancer.
• Individuals with a history of atypical nevi or moles in the eye may have an increased risk of developing choroidal melanoma. These abnormal growths can serve as precursors to cancerous changes in the choroid, necessitating close monitoring and early intervention.

Symptoms of Choroidal Melanoma

Recognizing the symptoms of choroidal melanoma is crucial for early detection and prompt treatment to preserve vision and prevent complications. Symptoms can vary depending on the stage of the cancer, with early-stage symptoms often being subtle and easily overlooked.

Early Symptoms:

• Blurred vision or changes in visual acuity may be one of the first signs of choroidal melanoma. These changes can impact daily activities such as reading or driving and may progress over time if left untreated.
• Floaters or flashes of light in the field of vision can also occur in the early stages of choroidal melanoma. While these symptoms are common and usually harmless, persistent or sudden onset of floaters may indicate underlying eye issues that require evaluation.

Advanced Symptoms:

• Vision loss or visual field defects can manifest as the choroidal melanoma progresses to advanced stages. These changes can significantly impair daily functioning and have a profound impact on the individual's quality of life.
• Eye pain or discomfort, particularly in the affected eye, can be a sign of advanced choroidal melanoma. The pain may be persistent and severe, affecting not only physical well-being but also emotional health due to the distress associated with chronic pain.

Diagnosis of Choroidal Melanoma

Diagnosing choroidal melanoma involves a comprehensive evaluation of the eye and its structures to confirm the presence of cancerous growths and determine the extent of the disease.

• Ocular examination, including a dilated eye exam, is essential for detecting abnormalities in the choroid and identifying suspicious lesions that may indicate melanoma. This exam allows the ophthalmologist to visualize the back of the eye and assess any changes in the choroidal tissue.
• Ultrasonography, such as A-scan and B-scan ultrasound, is commonly used to image the internal structures of the eye and evaluate the size and characteristics of choroidal melanoma. This non-invasive imaging technique provides valuable information about the tumor's location and features.
• Optical coherence tomography (OCT) is a high-resolution imaging tool that can reveal detailed cross-sectional images of the retina and choroid. By analyzing the layers of the eye, OCT helps in identifying the depth and extent of choroidal melanoma for accurate diagnosis and treatment planning.
• Fluorescein angiography is a diagnostic test that involves injecting a fluorescent dye into the bloodstream to visualize blood flow in the eye. This test can help identify abnormal blood vessels or leakage associated with choroidal melanoma, aiding in the assessment of tumor characteristics.

Treatment Options for Choroidal Melanoma

The treatment of choroidal melanoma aims to eradicate cancerous cells, preserve vision, and prevent metastasis to other organs. The choice of treatment depends on factors such as tumor size, location, and the individual's overall health.

• Medications: In some cases, targeted therapies or immunotherapies may be prescribed to treat choroidal melanoma. These medications work by targeting specific molecular pathways involved in tumor growth and immune evasion, offering a more tailored approach to cancer treatment.
• Dietary modifications: Following a balanced diet rich in antioxidants, vitamins, and minerals can support overall eye health and potentially reduce the risk of disease progression. Limiting the intake of processed foods, saturated fats, and excess sugar can also help maintain a healthy immune system.