On the occasion of the World Cancer Day (World Cancer Day), promoted on 4 February each year by the International Union Against Cancer (UICC), L'Oculista Italiano would like to dedicate to its readers a brief insight into the tumours affecting the eye.
Worldwide, more than 12 million people are diagnosed with cancer. However, clinical evidence shows that about 50% tumours could be prevented and/or treated by undergoing regular annual check-ups and adopting a correct lifestyle.
Correct information, targeted prevention and awareness-raising are therefore essential tools.
What are tumours of the eye?
Tumours affecting the eyes are divided into:
-Intraocular tumours, when the internal structure, i.e. the eyeball, is affected;
-orbital tumours, when the external structure, i.e. the orbit, is affected;
- adnexal tumours, when the adnexa of the eye (eyelids or lacrimal glands) are affected.
The most common intraocular tumours affecting adults and children respectively are the melanoma and the retinoblastoma.
Melanoma
Ocular melanoma is the most common form of neoplastic disease in the adult population, with between 400 and 500 new cases per year in Italy alone. Melanoma can be conjunctival, if it affects the conjunctiva, or uveal, if it arises in the uvea, the central membrane consisting of the iris, choroid and ciliary body.
Melanomas of the conjunctiva represent 2% of all ocular tumours and have a very low incidence, whereas tumours affecting the uvea are more frequent and can sometimes be fatal.
They affect around 6 million people each year, occur on average after the age of 50 and are more frequent among light-eyed individuals.
Ocular melanoma may not be diagnosed in time because it is asymptomatic or because the symptoms are mistakenly associated with other eye diseases.
In general, the symptoms of melanoma that could most commonly be linked to an ocular neoplasm are:
-blurred view;
-appearance of dark spots within the field of vision;
-sudden loss of vision;
-excessive sensitivity to light;
-pain in the eye;
-burning, tearing and reddening of the sclera, the white part of the eye.
La diagnosis of melanoma is performed by an ophthalmologist who will be able to determine certain clinical parameters of the patient such as pigmentation or visible changes in the eye. For the confirmation of a suspected tumour diagnosis, the patient may undergo various diagnostic tests, such as:
-ocular echography: whereby all the internal structures of the eye are examined;
-angiography: a procedure that allows the visualisation of blood vessels in the eye and identifies any anomalies;
-Magnetic resonance imaging: through which high-resolution images are obtained that allow a precise diagnosis and, if necessary, an appropriate choice of treatment.
The choice of therapeutic strategy to be adopted obviously depends on the patient's clinical condition and the severity of the neoplastic pathology. The main objective of any therapeutic option to be adopted, in any case, is aimed at both the preservation of the eye and the prevention of possible metastases.
Therapeutic interventions include:
-radiotherapy: commonly used in cases of ocular metastases or for the treatment of small or medium-sized melanomas;
-transpupillary thermotherapy: in which tumour cells are destroyed by the action of infrared laser beams;
-surgical techniques: i.e. surgical removal of the tumour; these techniques are only performed if the tumour mass affects the central vision.
Retinoblastoma
With an incidence of 1 in 20,000 children born, retinoblastoma is the most common neoplastic disease of the retina in children. This tumour form can occur in only one eye or, in the most severe cases, in both, and its onset can be hereditary or non-hereditary. If retinoblastoma is caused by genetic factors, the diagnosis generally occurs within the first year of age and in 40% of cases it manifests as a bilateral form; if, on the other hand, it is not caused by hereditary factors, the diagnosis occurs within two years of age and in 60% of cases it affects only one eye.
Moreover, the diagnosis is useful not only to determine the presence of the malignancy but also to determine the staging, i.e. the possible spread of the tumour mass to other parts of the body. Staging, in fact, is very important for the choice of the treatment plan to be carried out.
Conventionally, retinoblastoma is classified as:
-intraocular, when the tumour only affects the eye;
-extraocular, when the tumour has spread to parts outside the eye.
I symptoms main features of retinoblastoma include:
-leucocoria, i.e. a white reflection affecting the pupil;
-strabism;
-orbital cellulitis, an inflammation of the inner areas of the eye;
-hexophthalmia, a condition in which the eye becomes protruded from its normal position.
A diagnosis early treatment is essential to ensure that the child can preserve as much good vision as possible. However, only in 7-10% of cases is retinoblastoma diagnosed in time. Diagnostic tests useful for confirming the presence of retinoblastoma are fundoscopy, an examination of the ocular fundus, or ultrasound examinations.
The choice of treatment to be adopted depends largely on the stage and extent of the tumour mass. In general, therapeutic strategies for the treatment of retinoblastoma include:
-chemotherapy, through the administration of drugs capable of destroying cancer cells;
-radiotherapy, which uses high-frequency radiation and is generally used to treat very large ocular tumours;
-cryotherapy, in which cancer cells are destroyed thanks to low temperatures;
-the laser technique, which targets the blood vessels feeding the tumour mass;
-enucleation, i.e. the removal of the eye by surgery.
Bibliography:
-Tero T. Kivelä TT et al. Neonatal Retinoblastoma. Asia Pac J Oncol Nurs. 2017; 4(3): 197-204.
-Cassoux N et al. Retinoblastoma: Update on Current Management. Asia-Pac J Ophthalmol 2017;6:290-295.
-Dogrusöz M et al.Uveal Melanoma Treatment and Prognostication. Asia-Pac J Ophthalmol 2017;6:186-196.
Dr. Carmelo Chines
Direttore responsabile
English 
Italian