Retinoblastoma is a type of eye cancer where the proliferation of the cancerous cells happens in the retina. The retina is the sensitive layer, lining the inside of the eye and is usually made up of nerve tissues that sense light as it reaches the eye. Thereafter, it sends signals via the optic nerve to the brain, where these signals are construed as images. Being quite a rare form of eye cancer, it is usually diagnosed in children affecting either one or both eyes. Also Read: Intraocular Melanoma: Causes, Symptoms And Treatment
Retinoblastoma can be subdivided into two types, mainly:
Heritable or Bilateral Retinoblastoma:
It is caused by inheriting a defective gene in an autosomal dominant pattern, where even if only one parent has a single copy of the mutated gene, the risk of inheriting that gene by the child increases 50%.
Non-Heritable (Sporadic) Retinoblastoma:
It is caused by a random change in the RB1 gene during cell replication. In most cases, the Retinoblastoma is of sporadic origin.
Retinoblastoma usually occurs due to genetic mutations or an error in the DNA. The genetic error causes unhealthy cells to grow and proliferate instead of dying as in the normal case. Overtime these mutated abnormal cells accumulate in the eye to form a malignant tumour. Not only can this growing tumour spread to other parts of the eye, but also through the lymphatic vessels, it can gradually spread to other parts of the body. Although the exact cause of this genetic mutation is yet unknown, some researches show that children often inherit this condition from their parents. Also Read: What You Need to Know About Childhood Cancers
The various risk factors of intraocular melanoma include:
Age: The risk of retinoblastoma is more common in children below 3 years of age.
Genetic Mutation: It is more commonly diagnosed in children where one or both parent has the congenital form of retinoblastoma.
Since it usually affects children and infants, signs and symptoms are difficult to notice or understand. But the common ones include:
- Leukocoria (when light is shone into the eyes, a white reflection is seen, giving the impression that the pupil is white)
- Strabismus or crossed eyes or eyes looking in different directions
- Redness in the eye as in the case of blepharitis
- Puffiness or swelling of one or both eyes as in the case of stye
Retinoblastoma is often recurring hence in most cases; the doctor keeps a follow-up routine after treatment. In case, it is not diagnosed in time, it can spread to other parts of the body causing different forms of cancer.
It is strictly advisable to consult a doctor as soon as you notice any of the above-mentioned symptoms in your child to start the treatment at the earliest. The ophthalmologist usually performs a series of eye examination to look for enlarged blood vessels that might indicate the presence of a tumour. He may also perform other diagnostics including:
Imaging techniques like Ultrasound, Ct-scan, MRI-scan, etc.
Depending upon the biopsy results and the age of the child, treatment options may include:
- Radiation therapy including Internal radiation (brachytherapy) and External beam radiation
- Laser therapy or laser photocoagulation
- Cryotherapy or cold treatments using liquid nitrogen
- Surgery to remove the affected eye or place an eye implant or provide an artificial eye.