Retinoblastoma is a dangerous type of eye cancer that mainly strikes young children, usually those under five. Retinoblastoma starts in the retina, the light-sensitive tissue at the back of the eye, and arises when retinal cells transform and begin to grow out of control, forming tumours.
Early detection and treatment are necessary for protecting vision and stopping metastasis or the spread of cancer to other body parts. This article traverses over the symptoms, causes, and prevention strategies of retinoblastoma, providing an extensive understanding of this uncommon eye cancer.
Symptoms of Retinoblastoma
The symptoms of retinoblastoma can be subtle, especially in the early stages, making it crucial for parents, caregivers, and physicians to be vigilant. Early diagnosis substantially improves the chances of successful treatment. The most common and recognisable symptoms of retinoblastoma include:
Leukocoria
Leukocoria, often referred to as the “cat’s eye reflex,” is one of the symptoms of retinoblastoma. When light is shone into the affected eye, as happens when a flash is used for photography, the pupil may appear white or yellow rather than red.
This abnormal reflection is due to the presence of a tumour behind the eye, which reflects light in a distinctive way. Parents may first notice this symptom in photographs or during routine activities.
Strabismus
Strabismus manifests in the form of the eyes not aligning properly, and one or both eyes may turn in different directions. It can happen because a tumour disrupts normal eye movement or affects the child’s ability to focus with both eyes. Strabismus can be an early sign of retinoblastoma, especially if it appears suddenly.
Poor Vision or Vision Loss
Children with retinoblastoma may experience deteriorating vision, though this symptom can be complex to detect in infants and toddlers. If a child starts to squint, hold objects very close, or has difficulty tracking moving objects, this could be indicative of a vision impairment caused by the tumour.
Eye Redness and Swelling
Sometimes, there are no other symptoms of infection, but the eye may look red or swollen. Swelling around the eye can also occur if the tumour grows large enough to cause pressure in the orbital area. While these symptoms are less common in early-stage retinoblastoma, they can occur as the disease progresses.
Eye Pain or Discomfort
Children with more advanced retinoblastoma may show symptoms of pain or discomfort in the affected eye, though this is rare in the early stages. They may rub their eyes frequently or exhibit behaviours that suggest irritation.
Causes of Retinoblastoma
Retinoblastoma is brought about by mutations in the RB1 gene, which is a tumour-suppressor gene responsible for regulating cell division in the retina. When this gene mutates, it loses its ability to control the growth and division of retinal cells, leading to the formation of cancerous tumours.
Retinoblastoma can be divided into two primary categories, depending on whether the mutation develops by itself or is inherited.
Hereditary Retinoblastoma
Hereditary retinoblastoma accounts for about 40% of all cases. This form of the disease occurs when a child inherits a mutated copy of the RB1 gene from one parent. In hereditary cases, the mutation is present in all of the body’s cells, increasing the risk of developing retinoblastoma in both eyes (bilateral retinoblastoma).
These children also have a higher lifetime risk of developing other cancers, such as osteosarcoma (bone cancer) and soft tissue sarcomas, due to the presence of the mutation in different tissues.
Children with hereditary retinoblastoma tend to develop the disease at an earlier age, often within the first year of life. The mutation can be passed on to subsequent generations since it is found in the germline or inherited DNA.
Non-Hereditary Retinoblastoma
In non-hereditary retinoblastoma, the RB1 gene mutation occurs spontaneously in retinal cells during early fetal development and is not inherited from either parent. This form of retinoblastoma typically affects only one eye (unilateral retinoblastoma) and usually appears later, between the ages of one and three.
Children with sporadic retinoblastoma do not have the mutation in other cells and are not at a higher risk of getting other cancers because it is limited to retinal cells. If treatment is delayed, they still run the risk of vision failure in the affected eye.
Prevention Strategies for Retinoblastoma
While there is no guaranteed way to prevent retinoblastoma hereditary cases, several strategies can help reduce the risk, improve early detection, and facilitate better outcomes.
Genetic Counselling
For families with a known history of retinoblastoma, genetic counselling is a critical step in understanding the risk of passing the RB1 gene mutation to offspring. Genetic testing can determine whether parents carry the mutation and, if so, how likely it is for their children to inherit it.
Prenatal genetic testing can also be used to determine whether the unborn child has the RB1 mutation in cases of hereditary retinoblastoma. Early diagnosis lowers the risk of severe complications by enabling close monitoring and intervention as soon as symptoms appear.
Routine Eye Examinations
Regular eye examinations are vital, particularly for children with a family history of retinoblastoma. Ophthalmologists can detect abnormalities in the retina even before symptoms become noticeable to parents. For children at high risk of developing retinoblastoma, screening should begin shortly after birth and continue at frequent intervals throughout early childhood.
Retinal imaging, ultrasonography, and eye exams under anaesthesia may be recommended for high-risk infants to detect any early signs of tumour formation. Early intervention is vital in preserving vision and preventing the cancer from spreading.
Parental Awareness
It is essential to inform parents about the early indicators of retinoblastoma, such as strabismus and leukocoria, so that they can promptly seek medical help if these symptoms are noticed. Vigilance goes beyond the early years because children with hereditary retinoblastoma are more likely to develop other cancers over time. Parents should make sure their child gets regular checkups to watch out for any late-onset issues.
Advances in Medical Research
Recent advances in gene therapy and targeted treatments for retinoblastoma offer hope for better prevention strategies in the future. Researchers are investigating ways to correct the RB1 gene mutation or prevent its damaging effects on retinal cells, which could ultimately reduce the incidence of retinoblastoma in high-risk populations.
Conclusion
In conclusion, retinoblastoma is an uncommon but dangerous type of eye cancer that normally affects young children. Early detection is key to enhancing treatment outcomes and preserving vision. Common signs of retinoblastoma include leukocoria, strabismus, and vision issues. Parents and guardians should be aware of these symptoms and seek medical help right away if they are noticed.
