Retinoblastoma is a type of eye cancer, which primarily begins in the retina of the eye. The retina is the innermost, sensitive layer of tissue inside the eye. The retina comprises of nerve tissue which senses the light when it reaches the eye. The retina then sends signals to the brain via the optic nerve. The brain, in turn, understands the signals and interprets the images.
Retinoblastoma typically impacts children; however, it can also impact adults. It is a very uncommon form of cancer. But in children, it is the most common form of cancer. Cancer can occur in both or one eye.
Symptoms of retinoblastoma
As retinoblastoma generally impacts children and infants, the symptoms are often hard to understand. However, some possible signs will include:
- Red eyes
- Swelling in the eyes
- An issue where the eyes appear to be focussed in different directions
- A white dot in the centre of the eye (pupil), which is clear when the light is reflected upon it
However, if a parent notices any abnormal changes in the eyes of the child, immediate medical attention should be sought. Moreover, since retinoblastoma is a very rare form of cancer, the healthcare provider may examine other causes for the issue.
Causes of retinoblastoma
This form of cancer develops when the nerve cells in the retina form abnormal genetic mutations. These mutations lead to a condition where the cells continue to grow and multiply when ideally, they should die. This abnormal number of cells form a mass, known as a tumour.
Retinoblastoma can also spread to other parts of the eyes or the nearby structures. It can also impact other areas of the body, such as the brain and spine. In most cases, the actual cause of mutations is not clear. However, children can inherit an abnormal genetic mutation from their parents.
In the case of inherited gene mutation, it is possible to pass it on to children, even if one parent has the issue. Each parent carries a 50 per cent chance to increase the risk of genetic mutation in the child. Children that have this inherited condition, tend to develop this condition at an early age. Moreover, hereditary retinoblastoma impacts both the eyes, rather than just one.
Complications of retinoblastoma
Children with an inherited form of retinoblastoma, are more prone to develop other types of cancer in other body parts. This can happen even after the retinoblastoma is treated. This could be prevented by regular medical examinations to diagnose any other types of cancer or issue.
Prevention of retinoblastoma
Since the actual cause of retinoblastoma is not known, there is no definitive way to prevent this issue. However, some measures can help prevent retinoblastoma.
For families that have a risk of retinoblastoma, prevention may not be possible. But genetic testing can provide an advantage to families to know which child is at a higher risk of developing the issue. The parents can then resort to regular eye exams to help diagnose the condition early. This can help to treat the issue and minimise complications.
Diagnosis of retinoblastoma
The doctor will conduct a few exams to diagnose retinoblastoma. These tests include:
- Eye exam: The doctor will conduct an exhaustive eye exam to understand the symptoms and underlying causes. For a clearer picture, the child could be placed under the influence of mild anaesthetics to keep the child still.
Imaging tests: Imaging tests such as ultrasound, CT scans or MRI can be used by doctors to understand the retinoblastoma has grown to impact other structuresnearby the eyes.In some cases, the doctor may also refer the patient to other specialists, such as an oncologist, or a genetic counsellor for diagnosis or confirmation of condition.
Treatment of retinoblastoma
The treatment for retinoblastoma depends on the general health of the patient, the cause of retinoblastoma, the size and location of the tumour, and if cancer has spread to other structures. The main objective of the treatment is to cure cancer. However, the procedure could impact the vision.
Some treatments for retinoblastoma include:
Chemotherapy: Chemotherapy through blood vessels or pill can be used to kill the cancer cells. The drug used in chemotherapy travels through the body to attack the cancer cells. Specifically, for children, chemotherapy may be used to shrink the size of the tumour. Once, the tumour has shrunk, another form of treatment such as radiation therapy, cryotherapy, laser therapy, etc. can be used to eliminate other cancer cells. Chemotherapy is very useful in cases, where cancer has spread to nearby structures.
Radiation therapy: In radiation therapy, X-rays, protons, and other high-energy beams can be used to destroy cancer. Radiation therapy is of two kinds:
- Internal radiation is also known as brachytherapy where the device is placed near or in the tumour. This minimises damage to nearby tissues.
- External beam radiation directs high-powered beams to the tumour from an external device. This can have side effects since the radiation can also impact nearby tissues.
Laser therapy: In this form of treatment, a laser is used to damage blood vessels, which provide the primary supply of oxygen and nutrients to the tumour.
Cryotherapy: This form of treatment uses an extremely cold temperature to kill cancer cells.
Surgery: When all other non-invasive or minimally invasive formsof treatment fail to provide any relief or if the tumour is too large, the doctor may recommend surgery to cure cancer. This could involve removing the affected eye, an eye implant, or placing an artificial eye.
Overall, retinoblastoma is rare but cannot be prevented. However, it is possible to reduce complications and improve the quality of life through regular eye exams.