Dr. Ziad Bashshur, visiting Ophthalmologist specialising in Medical and Surgical Retina at Moorfields Eye Hospital Dubai shares how to spot and treat eye cancer.
Eye cancers vary and can range from ocular surface tumours that can be malignant or benign to intraocular tumours that develop inside the eye. These abnormal growths can arise from the eye (primary) or spread to the eye from cancers elsewhere in the body. This process is known as metastatic.
Eye cancer is not age-related, but different types of cancer are likely to occur at a higher or lower frequency depending on age. In children, the most common eye cancer is called retinoblastoma, an eye cancer that begins in the retina, and it can be caused by an inherited gene mutation that occurs in 1 out of 15,000 live births. In adults, the most common intraocular tumours are those that spread or metastasize from other cancers in the body, usually lung or breast cancer.
Additionally, as the eye is the second most common location for melanomai in the body after the skin, the most common primary intraocular tumour is melanoma, which occurs in 6 per million people worldwide. This type of cancer predominantly affects people of Caucasian descent and can, unfortunately, manifest without any warning signs.
A tumour may progress and grow for months or years before being discovered. Eventually, tumours may cause visual distortion once they integrate with the visual axis. Adults generally experience minimal symptoms from eye cancer; however, blurred vision can occur if the tumour is producing fluid that involves the centre of vision.
Predisposing factors for the development of melanoma include the existence of a nevusii in the eye, ocular melanocytosisiii, being of Caucasian descent, and non-brown eye colour.
In children, early warning signs of retinoblastoma are leukocoriaiv and strabismusv. Unfortunately, children could have a difficult time verbalising any symptoms they may have, so it is up to the parents and paediatricians to identify worrying signs. The risk for developing retinoblastoma increases when a direct relative (such as a parent) has a history of the disease.
Tumour diagnosis is clinical, which means a specialised ophthalmologist must perform a complete eye exam, including a retinal exam after pupil dilation, to determine if there are any tumours in the eye.
Ophthalmologists have a range of imaging tools at their disposal to aid with the diagnosis. These include ultrasonographyvi, fundus photographyvii, fluorescein angiographyviii, and ocular coherence tomography (OCT)ix.
For childhood cancers like retinoblastoma, treatment involves systemic chemotherapyx, local laser treatmentxiand cryotherapyxii, intraocular injections of chemotherapyxiii, and intra-arterial chemotherapyxiv.
A type of radiation therapy known as brachytherapy is another treatment option where a radioactive plaque is placed on the surface of the eye near the area of the tumour. Enucleation or removal of the eye is reserved for cases that are advanced or not responding to treatment. The type of treatment selected depends on tumour size and location.
In adults, melanoma is treated with plaque brachytherapy, proton beam radiotherapyxv, stereotactic radiotherapyxvi, or enucleation. There is no role for systemic chemotherapy unless the tumour has spread to the rest of the body. Unfortunately, chances of survival are relatively low once the disease has spread to the rest of the body.
Despite successful treatment, frequent follow up is essential for lifesaving, eye-saving, and vision-saving goals. This is especially true, in children with retinoblastoma mutations in the cancer suppressor gene, which means that other cancers can arise elsewhere in the body.
Additionally, complications after treatment can occur, which can be related to the radiation. This complication must be managed effectively to preserve the vision and the eye. Patients with a history of ocular melanoma require screening for metastasis (mainly to the liver and lung).
In conclusion, intraocular tumours pose a significant risk to the vision and the life of the patient. The spread of cancer from the eye to the body is generally difficult to treat, and survival is usually very poor if the disease is not treated quickly.
While there are no proven methods to help prevent eye cancer, early detection is key and can help reduce the number of complications the patient experiences.
To maintain optimal eye health, patients must visit their ophthalmologists regularly for eye exams. For adults, we recommend annual dilation and fundus examinations and in children red reflex testing should be performed at every paediatric visit, starting once the child is school age (age 3-5).