Retinoblastoma: Overview

Retinoblastoma is a rare and potentially severe type of childhood eye cancer that primarily affects the retina, the light-sensitive tissue at the back of the eye. This cancer originates from immature cells in the retina called retinoblasts, which can undergo uncontrolled growth and form tumours. Retinoblastoma is most commonly diagnosed in infants and young children, typically before age 5.

The condition can occur in one or both eyes and may be hereditary or non-hereditary. Hereditary retinoblastoma is linked to mutations in the RB1 gene, which usually helps regulate cell growth. In non-hereditary cases, the transformation occurs spontaneously in retinoblast cells.

---

Types of retinoblastoma:

Hereditary Retinoblastoma :

• Bilateral Hereditary Retinoblastoma : This type affects both eyes and is often associated with a genetic mutation in the RB1 gene inherited from a parent. Children with bilateral hereditary retinoblastoma have an increased risk of developing multiple tumours in both eyes.
• Unilateral Hereditary Retinoblastoma : Only one eye is affected in this type, but the child carries a germline mutation in the RB1 gene. While the conversion is present in all cells, retinoblastoma develops in only one eye. There is a risk of developing other cancers later in life.

Non-Hereditary (Sporadic) Retinoblastoma :

• Unilateral Sporadic Retinoblastoma : This type affects only one eye and typically arises from a mutation in the RB1 gene that occurs spontaneously in retinoblast cells. It is not inherited from a parent.
• Bilateral Sporadic Retinoblastoma : This rare type affects both eyes but is not associated with a hereditary genetic mutation. Instead, mutations occur independently in both retinoblasts.

---

symptoms of retinoblastoma

White Pupil (Leukocoria): One of the hallmark signs of retinoblastoma is a white or cloudy pupil appearance, often noticeable in flash photographs. This is due to a tumour blocking the normal red reflex in the eye.

Strabismus (Crossed Eyes) : Sudden or persistent misalignment of the eyes, also known as strabismus, can be a symptom of retinoblastoma. One eye may be deviating inward or outward.

Reduced Vision : Children with retinoblastoma may experience decreased vision in one or both eyes. This may be observed as a lack of visual responsiveness, squinting, or difficulty tracking objects.

Eye Pain or Redness : Some children with retinoblastoma may experience eye pain, redness, or irritation. This can be due to the presence of a tumour or inflammation in the eye.

Changes in Eye Appearance : Swelling, inflammation, or changes in the colour or appearance of the eye, such as a bulging or enlarged eye, may indicate retinoblastoma.

Strabismus : Sudden or persistent misalignment of the eyes, also known as strabismus, can be a symptom of retinoblastoma. One eye may be deviating inward or outward.

Changes in Eye Movement : If the tumour affects the muscles controlling eye movement, your child may have difficulty moving their eye in specific directions.

Poor Red Reflex : During a routine eye examination, a healthcare provider may notice an absence or abnormality in the red reflex (the reflection of light from the back of the eye) when using an ophthalmoscope.

---

When to see a doctor?

Take a doctor's appointment if you are getting tired quickly and need to know why. Your haemoglobin count has fallen if you observe the above Retinoblastoma symptoms or during a blood test.

Causes of Retinoblastoma

Hereditary Retinoblastoma : Sometimes, individuals inherit a mutated RB1 gene from a parent. Hereditary retinoblastoma tends to occur earlier in life, often affecting both eyes. Individuals with hereditary retinoblastoma have a higher risk of developing other cancers later in life, known as second primary malignancies.

Non-Hereditary (Sporadic) Retinoblastoma : Most cases of retinoblastoma are non-hereditary and result from spontaneous mutations in the RB1 gene that occur in retinoblast cells during early development. Non-hereditary retinoblastoma typically affects only one eye and may be diagnosed at a slightly later age than hereditary cases.

It's important to note that while mutations in the RB1 gene are the primary genetic cause of retinoblastoma, not all individuals with RB1 mutations will develop the condition. Other factors, such as additional genetic changes or environmental influences, may contribute to the development of retinoblastoma tumours.

---

Risk Factors of Retinoblastoma:

Genetic Mutations : The most significant risk factor for retinoblastoma is the presence of mutations in the RB1 gene. These mutations can be hereditary (inherited from a parent) or non-hereditary (occurring spontaneously during early development). Individuals with a family history of retinoblastoma or known RB1 gene mutations have a higher risk.

Age : Retinoblastoma primarily affects young children, with most cases diagnosed before age 5. The risk decreases as a child grows older.

Heredity : A family history of retinoblastoma or other RB1-related cancers increases the risk of developing the condition, especially if a parent or sibling has been diagnosed.

Gender : Retinoblastoma occurs slightly more frequently in girls than in boys.

Race and Ethnicity : Retinoblastoma can affect individuals of all races and ethnicities, but some studies suggest a slightly higher incidence among specific populations.

Environmental Factors : While genetic mutations are the primary cause of retinoblastoma, ecological factors may sometimes play a role. However, specific environmental risk factors need to be better defined.

---

Complications of Retinoblastoma:

Vision Loss : Depending on the size and location of the tumour, retinoblastoma can cause vision impairment or complete vision loss in the affected eye(s). Prompt diagnosis and treatment are essential to preserve vision whenever possible.

Spread of Cancer (Metastasis) : If left untreated or the cancer spreads beyond the eye, retinoblastoma can metastasize to other body parts, such as the brain, bones, and lymph nodes. Metastatic retinoblastoma is more challenging to treat and may have a poorer prognosis.

Secondary Cancers : Individuals with a history of retinoblastoma, especially hereditary cases, have a higher risk of developing second primary malignancies later in life, such as osteosarcoma (bone cancer) or soft tissue sarcomas.

Emotional and Psychological Impact : A diagnosis of retinoblastoma and the associated treatments can have a significant emotional and psychological impact on the child and their family. Coping with the challenges of cancer treatment and potential vision loss can be stressful.

Long-Term Follow-Up : Survivors of retinoblastoma require lifelong follow-up care to monitor for potential late effects, recurrence, and the development of secondary cancers. Regular medical examinations and screenings are essential for ongoing health management.

Impact on Family : The diagnosis and treatment of retinoblastoma can place emotional and financial strain on families. Support and resources are essential for helping families navigate the challenges of cancer treatment.

---

Diagnosis of retinoblastoma:

Clinical Examination:

An ophthalmologist or paediatrician will thoroughly examine the child's eyes and overall health.

The presence of a white pupil (leukocoria), strabismus (crossed eyes), changes in eye appearance, or other visual abnormalities may raise suspicion of retinoblastoma.

Ophthalmoscopy and Fundus Photography:

Ophthalmoscopy involves using a specialized instrument (ophthalmoscope) to examine the inside of the eye, including the retina.

Fundus photography captures detailed retina images, allowing for documentation and monitoring of abnormalities.

Ultrasound (Ocular Ultrasonography):

Ultrasound may be used to visualize the eye's internal structures, significantly if cataracts or other conditions obstruct the view.

Imaging Studies:

Magnetic Resonance Imaging (MRI) or Computed Tomography (CT) scan may be performed to assess the extent of the tumour and whether it has spread beyond the eye.

Biopsy and Pathological Examination:

Sometimes, a tumour biopsy may be performed to confirm the diagnosis and determine the type of retinoblastoma (heritable or non-heritable).

---

Treatment retinoblastoma:

Intra-Arterial Chemotherapy (Chemotherapy Directly to the Eye):

This targeted chemotherapy involves delivering anticancer drugs directly into the artery that supplies blood to the eye (ophthalmic artery).

Intra-arterial chemotherapy aims to shrink the tumour and reduce the need for systemic chemotherapy or radiation.

Systemic Chemotherapy:

Chemotherapy drugs are administered orally or intravenously to target cancer cells throughout the body.

Systemic chemotherapy is often used to treat large tumours or cases where the tumour has spread beyond the eye.

Focal Therapies:

Laser therapy (photocoagulation) or cryotherapy (freezing) may destroy small tumours or areas of tumour growth on the retina.

These therapies are minimally invasive and are aimed at preserving vision.

Radiation Therapy:

External beam radiation therapy uses high-energy X-rays to target and destroy cancer cells.

Radiation therapy is used in cases where other treatments may not be effective, but it is generally avoided whenever possible due to potential long-term risks.

Enucleation (Surgical Removal of the Eye):

Enucleation may be necessary if the tumour is large or aggressive and cannot be treated while preserving vision.

After enucleation, a prosthetic eye (ocular prosthesis) is placed for cosmetic purposes.

Intraocular Focal Therapy:

Devices like radioactive plaques or beads may be implanted directly into the eye to deliver targeted radiation to the tumour.

This technique is used for localized tumours and is considered in select cases.

Clinical Trials:

Participation in clinical trials may provide access to experimental treatments and therapies under investigation.

---

Wilms tumour Dos and Don’ts

Retinoblastoma Care at Medicover Hospitals

At Medicover Hospitals, we provide comprehensive and specialized care for children diagnosed with retinoblastoma. Our dedicated team of experienced medical professionals and specialists is committed to offering the best possible treatment and support for children and their families. Here's how we provide retinoblastoma care at Medicover Hospitals