In Spain, some 240 cases of choroidal melanoma, the most widespread malignant ocular tumour in adults, are reported annually. “But the number of cases is even higher if we talk about ocular tumours secondary to other cancerous processes, since almost 10% of tumours located in other areas ultimately lead to metastasis in the eye, because of the high vascularisation of the organ, especially of the macula and optic nerve,” according to Dr José García-Arumí, a retina specialist at IMO and a leading international expert on ophthalmic oncology.
According to the ophthalmologist, the main primary tumours with ocular metastasis are breast cancer in women and lung cancer in men. In many cases, symptoms such as loss of vision orretinal detachment result in patients visiting the ophthalmologist, who discovers the existence of an undiagnosed primary tumour through a fundus test. “In the case of lung cancer, this occurs in 50% of patients with ocular metastasis, who are diagnosed with a lung tumour through an eye examination,” explains IMO specialist. Because of this, he adds, although there are no symptoms as tumours are often asymptomatic, “all of the population should have a routine annual examination of the fundus after the age of 50, which is when it is more common for ocular tumours to appear". This would not only facilitate the diagnosis of an ocular tumour; it would also, in many cases, enable the existence of the primary tumour causing the metastasis in the eye to be discovered. “An early diagnosis of a primary ocular melanoma would also prevent the opposite effect, i.e. metastasis of cancer cells to other organs, especially the liver,” notes Dr García-Arumí.
A new drug inhibits ocular melanoma metastasis in the liver
For the treatment of hepatic metastasis from choroidal melanoma, IMO specialist announces that “we have a new drug called ipililumab, which is a compound of monoclonal antibodies that inhibit the growth of cancer cells.” According to the ophthalmologist, the treatment has been used successfully for over a year to combat metastasis of cutaneous melanoma and, since a few months ago, “we have been using it, also with good results, for metastasis of ocular melanoma in the liver.”
Treatment of ocular tumours
The most common treatment to combat ocular melanoma is brachytherapy, which involves the use of a radioactive ruthenium or iodine plate, which is placed on the tumoural area for a few days. As it is local, it prevents external radiation and minimises possible side effects. It is over 90% effective if applied in the early stages, but, if the tumour is not detected early, there is a high risk of metastasis, which mainly affects the liver, and has a mortality rate of 90%. In some cases, brachytherapy is applied in combination with endoresection, a surgical procedure that involves surgically removing the tumour by means of a laser and vitrectomy. It is sometimes necessary to cause a retinal detachment to gain access to the tumour and remove it with a laser and vitrectome (an instrument that breaks up the tumour and sucks up the fragments). Another recent advance in the field of choroidal melanoma is cytogenetics, which enables the patient’s vital prognosis to be studied. The head of IMO’s Ophthalmic Oncology Department explains that “through a biopsy, an analysis is carried out of chromosome 3, which, in all healthy individuals, is repeated. If it is observed that the patient only has one (monosomy), the risk of metastasis is increased. The risk is also greater if a multiplication of chromosome 8 (trisomy) is observed.” Although, in most cases, patients prefer not to know their prognosis, it is an important step forward in the study of DNA and tumour tissue, which, "in the future, will enable us to create drugs that can effectively and selectively attack cancer cells,” he adds.
As well as choroidal melanoma, another type of tumour of the sub-retinal layer exists, called choroidal haemangioma. It is a benign tumour - with no risk of metastasis - "but can develop rapidly and aggressively, posing a risk to vision by threatening the optic nerve (the transmitter of images from the retina to the brain) and the macula.” Choroidal haemangioma is treated with photodynamic therapy, a technique that, for many years, was applied to age-related macular degeneration (AMD). A study led by Dr José García-Arumí a few years ago demonstrated the effectiveness of the therapy to treat this type of ocular tumour. The treatment, which involves the intravenous administration of a drug and subsequent application of a laser, “acts selectively on the tumour, causing minimal damage to the retina,” explains the ophthalmologist.
Retinoblastoma: a white shadow in the pupil
Retinoblastoma is another type of ocular tumour which, in 50% of cases, is passed on from one generation to another. It affects one in every 15,000 newborn infants and is the most common malignant eye tumour in childhood.. Treatment is usually a combination of radiotherapy and chemotherapy. “Selective treatment is currently being carried out with the application of chemotherapy through the ophthalmic artery,” explains IMO ophthalmologist, who adds that “it is a treatment that reduces the risk of side effects in the rest of the body.” This type of tumour is highly aggressive, so early diagnosis and treatment are essential to save the eye and eliminate the need for enucleation (total removal of the eye). The most obvious symptom is the appearance of a white spot in the infant’s pupil. Although this blotch can be caused by other ailments, it is advisable to visit the ophthalmologist immediately because, “as a general rule, a pupil that is not completely black has some kind of problem,says Dr García-Arumí.
Advances in diagnostic technology
The specialist highlights the effectiveness of new diagnostic techniques in combating ocular tumours. According to him, technology has advanced considerably in recent years and enables us to combat intraocular tumours with an ever-increasing success rate. “Having diagnostic imaging technology such as 3D ultrasound imaging, retinography, wide-field angiography and nuclear magnetic resonance enables us not only to carry out accurate and early diagnosis, but also to study the height, size, type, growth rate and specific location of the tumour in order to be able to select the most appropriate treatment,” he says. IMO is one of the leading centres in the field of ocular oncology. It has been a pioneer in the use of important treatments in this field, such as ruthenium plaque brachytherapy and, more recently, a drug to combat liver metastasis. It has also participated in multicentre clinical trials that have demonstrated the effectiveness of photodynamic therapy for the treatment of certain ocular tumours. At the head of IMO’s Ophthalmic Oncology Department is Dr José García-Arumí, Professor of Ophthalmology at the Autonomous University of Barcelona (UAB), Head of the Ophthalmology Department of Vall d’Hebrón Hospital in Barcelona and Secretary of the Spanish Retina and Vitreous Society (SERV).