Melanoma, a dangerous form of skin cancer, presents clear warning signs that everyone should recognise. The hallmark indicators include new or changing moles, along with rough patches and alterations in skin colour. This disease affects over 200,000 Americans annually, with cancerous lesions capable of emerging anywhere on the body. However, medical professionals are raising awareness about a less common but equally perilous site for melanoma: the eyes.
Understanding Ocular Melanoma
Melanoma can develop on the eyelids, areas frequently exposed to harmful ultraviolet (UV) radiation, making them susceptible to lesions. If left untreated, these cancers may penetrate deeper into the eye and even reach the brain, significantly reducing treatment success rates. More alarmingly, melanoma can originate in areas without skin, such as inside the eye itself, in a condition known as ocular melanoma. This category includes subtypes like uveal melanoma and conjunctival melanoma.
The Cellular Connection Between Skin and Eyes
Both the skin and eyes contain melanocytes, cells responsible for producing melanin, the pigment that colours skin, eyes, and hair. Damage or mutations in these cells lead to melanoma. While sun exposure is a common cause of skin melanoma, uveal and conjunctival melanomas are not primarily linked to UV light. Instead, individuals with lighter eye colours or pre-existing conditions such as near-sightedness may face a higher risk.
The Rising Threat and Importance of Detection
As melanoma and skin cancer rates increase across the nation, eye doctors are urging Americans to maintain regular eye examinations every one to two years. These check-ups are vital for spotting potentially cancerous changes early. People should also be vigilant for subtle symptoms like blurred vision, spots in their vision, or irritation in or around the eye.
Dr Jacqueline Bowen, an eye doctor and president of the American Optometric Association, emphasised the variability of skin cancer involving the eye. She stated, 'Skin cancer involving the eye can appear in several different ways. Some start in or around the eye itself, while others spread to the eye from elsewhere in the body.'
Statistics and Trends in Melanoma
Approximately one million US adults are currently living with melanoma, the deadliest form of skin cancer, with around 212,000 new diagnoses expected this year. The mortality rate stands at about two per 100,000 people, resulting in roughly 8,000 deaths annually. Over the past three decades, melanoma rates have surged dramatically.
According to the American Academy of Dermatology, diagnosis rates doubled from 1982 to 2011, followed by a 31.5 percent increase between 2011 and 2019. Trends show a three percent annual rise in women over 50, while men under 50 have experienced a one percent yearly decrease. Rates among women under 50 and men over 50 have remained stable.
Specifics of Ocular Melanoma Subtypes
Uveal and conjunctival melanomas are two primary forms of ocular melanoma. In early stages, ocular melanomas often present no symptoms, but as they progress, patients may notice blurry vision, floaters, flashes, or changes in pupil shape. The exact causes remain unclear, though lighter eye and skin colours are considered risk factors. The role of UV light in ocular melanoma development is not well understood.
Each year, there are about 2,000 new cases of ocular melanoma in the US, as reported by the Melanoma Research Foundation. Conjunctival melanoma, which develops in the clear tissue over the eye, is exceedingly rare, with roughly 130 cases annually in the US and fewer than one in one million worldwide. Symptoms include irritation, redness, or a sensation of something stuck in the eye, potentially leading to vision loss or blurry vision as it advances.
Uveal melanoma originates in the middle layer of the eye, known as the uvea, and is the most common eye cancer. Similar to other forms, its causes are not fully known, but it is not believed to be influenced by UV light.
Expert Insights on Early Detection
Dr Bowen highlighted the silent nature of some eye cancers, stating, 'It’s important to note that some of the most serious eye cancers, particularly uveal or ocular melanoma, often cause no pain or vision changes in the early and even mid stages. Uveal melanoma is life-threatening because the retina is an extension of the brain, providing a direct pathway for cancer to spread if it goes undetected.'
She stressed the necessity of annual comprehensive eye exams, even in the absence of symptoms. During these exams, optometrists use specialised microscopes to detect small or early precancerous and cancerous lesions in the eye and surrounding structures. Many eye cancers are identified during routine check-ups before symptoms appear, greatly improving patient outcomes.
Treatment Options and Prognosis
While there are no definitive cures for ocular melanoma, treatments such as specialised laser therapy or plaque brachytherapy can effectively kill tumors. Doctors do not typically declare patients 'cured,' but they may achieve a status called NED, meaning no evidence of disease.
Dr Bowen urged anyone experiencing changes in their eyes or vision to consult an eye doctor promptly, especially if symptoms persist for several weeks or worsen. She added, 'Early detection matters at every age, including in children, where rare but life-threatening eye cancers such as retinoblastoma may only be detected through a comprehensive eye exam.'
In summary, vigilance and regular medical check-ups are paramount in combating the hidden threat of ocular melanoma, ensuring better health outcomes for all.
