What is Retinoblastoma?
Retinoblastoma refers to cancer of the retina, the light-sensitive layer of the eye which contains rods and cones to help us see in either dimly or brightly-lit settings. Retinoblastoma usually begins during childhood and may occur in one or both eyes. The cancerous cells may spread, or metastasize, to nearby structures such as the brain and spine.
What is Retina?
The retina is the inner layer in your eye. It transmits visual input through the optic nerve to your brain, where it is processed and interpreted as images.
What are the Causes of Retinoblastoma?
Retinoblastoma occurs due to genetic mutations in the nerve cells present in the retina. As a result, the cells continue to grow and multiply uncontrollably which leads to an abnormal mass of cells called a tumour. It can also be inherited from one’s parents, which is called congenital retinoblastoma.
What are the Symptoms of Retinoblastoma?
The symptoms of retinoblastoma may include:
- Appearance of a white colour in the pupil upon a light flash when taking a photograph
- Eyes may appear to look in opposite directions
- Ocular inflammation
- Eye redness
How is Retinoblastoma Diagnosed?
Your eye specialist will explore your medical history, clinical symptoms, and lifestyle. To confirm retinoblastoma, diagnostic tests are performed which include:
- A comprehensive eye exam
- Imaging tests such as ocular ultrasound, computerized tomography (CT) scan, and magnetic resonance imaging (MRI) scan
What are the Treatment Options for Retinoblastoma?
The therapies involved in the treatment of retinoblastoma are similar to the cancer therapies used for other body organs/tissues. The choice of treatment depends upon the severity of retinoblastoma.
The different treatment therapies include:
Chemotherapy
It involves the use of drugs/chemicals to suppress the growth of cancer cells and kill them. For the treatment of retinoblastoma, medications may be administered in the veins of the arm, called the intravenous (IV) route, or they may be given in the form of oral tablets. The drug enters the bloodstream, targets the cancerous cells, and destroys them.
Other forms of chemotherapy for the treatment of retinoblastoma include:
Intra-Arterial Chemotherapy
In this procedure, the drug is injected into an artery in the eye via a tiny tube called a catheter. Thus, it is delivered directly to the tumour site. For some people, the doctor may inflate the artery with a tiny balloon to administer the drug close to the tumour.
Intravitreal Chemotherapy
In this procedure, the drug is injected into the intravitreal cavity of your eye. It is used for the treatment of retinoblastoma that has spread within the eye.
Radiation Therapy
In this procedure, high-energy beams such as protons and X-rays are used to kill the cancer cells. There are two types of radiation therapies used for the treatment of retinoblastoma. These include:
External Beam Radiation
In external beam radiation, high-power beams are focused on the tumour site from a large machine placed outside the body.
Internal Radiation, also called Brachytherapy
In brachytherapy, a small disk-like device made of radioactive material is temporarily placed near or within the tumour. It emits radiation to the tumour site and thus minimizes the risk of affecting the healthy tissue.
Cryotherapy/Cold Treatment
In cryotherapy, a very cold substance - usually liquid nitrogen - is placed near or in the cancer cells. After the cells freeze, the cold substance is removed and the cells are thawed. This process of freezing and thawing is repeated a few times in each cryotherapy session to kill the cancerous cells.
Laser Therapy, also called Laser Photocoagulation
In this procedure, a laser is used to destroy blood vessels that supply oxygen and nutrients to the tumour, which ultimately kills the retinoblastoma cells.
Surgery
When the retinoblastoma is too big to be treated by other methods, surgery may be performed to remove the tumour. Sometimes, eye removal surgery called enucleation may be performed to prevent the spread of cancer to other parts of the body. This surgery may be followed by the placement of an eye implant or an artificial eye to help restore a normal appearance.
Surgery may have its own risks and complications such as infection and bleeding. Discuss with your doctor before you proceed.
