Retinoblastoma

Retinoblastoma is a rare type of eye cancer that develops in the retina, the light-sensitive tissue lining the back of the eye. It is the most common primary eye cancer in children and usually occurs before the age of 5 years.

Although hearing the word "cancer" can be frightening, advances in diagnosis and treatment have dramatically improved outcomes. Today, the vast majority of children diagnosed with retinoblastoma in developed countries survive the disease, and many are able to retain useful vision in one or both eyes.

Early diagnosis is critical. Parents and caregivers who notice an abnormal appearance of a child's eye should seek prompt evaluation by an eye care professional.

What Is the Retina?

The retina is the thin layer of nerve tissue at the back of the eye that captures light and sends visual information to the brain through the optic nerve.

In retinoblastoma, immature retinal cells begin to grow uncontrollably, forming one or more tumors within the eye.

These tumors can interfere with normal vision and, if left untreated, may spread beyond the eye.

What Causes Retinoblastoma?

Retinoblastoma develops because of mutations involving the RB1 gene, a tumor suppressor gene that normally helps regulate cell growth.

There are two forms of retinoblastoma:

Heritable Retinoblastoma

Children with the heritable form have a mutation in one copy of the RB1 gene in all of their body's cells.

Features include:

• Often affects both eyes (bilateral disease)
• May involve multiple tumors
• Can be passed on to future generations
• Carries an increased risk of other cancers later in life

Non-Heritable (Sporadic) Retinoblastoma

This form occurs when RB1 mutations develop only within retinal cells.

Features include:

• Usually affects one eye
• Often presents with a single tumor
• Is generally not passed to children

Signs and Symptoms of Retinoblastoma

The most common sign of retinoblastoma is leukocoria, or a white pupil reflex.

Instead of the normal "red reflex" seen in photographs, the pupil may appear white.

Other symptoms and signs include:

• A white pupil in photographs
• Crossed eyes (strabismus)
• Poor vision
• Eye redness
• Eye swelling
• Eye pain
• Different-colored pupils
• Enlarged pupil size
• Rarely, protrusion of the eye

Because young children cannot describe vision changes, parents are often the first to notice abnormalities.

How Is Retinoblastoma Diagnosed?

Prompt diagnosis is essential.

Dilated Eye Examination

A pediatric ophthalmologist or ocular oncologist examines the retina to identify tumors and determine their size and location.

Young children often require an examination under anesthesia (EUA) to allow a thorough evaluation.

Ocular Ultrasound

Ultrasound can identify characteristic calcium deposits within the tumor.

Retinal Imaging

Specialized imaging helps document tumor size and monitor treatment response.

MRI

Magnetic resonance imaging (MRI) may be used to evaluate:

• Extension into the optic nerve
• Involvement outside the eye
• The pineal gland in hereditary cases

Genetic Testing

Testing for RB1 mutations helps:

• Determine whether the disease is hereditary
• Guide screening of family members
• Inform future family planning

How Is Retinoblastoma Treated?

Treatment depends on:

• Tumor size
• Number of tumors
• Whether one or both eyes are involved
• The child's overall health
• Whether the cancer has spread

The goals of treatment are to:

• Save the child's life.
• Preserve the eye whenever possible.
• Maximize visual potential.

Chemotherapy

Chemotherapy is commonly used to shrink tumors.

Methods include:

Systemic Chemotherapy

Medication is delivered through the bloodstream.

Intra-Arterial Chemotherapy

Chemotherapy is delivered directly into the artery supplying the eye, allowing high concentrations to reach the tumor while limiting exposure to the rest of the body.

Intravitreal Chemotherapy

Medication is injected directly into the eye to treat vitreous tumor seeds.

Focal Treatments

After tumors shrink, local therapies may be used, including:

• Laser photocoagulation
• Cryotherapy (freezing treatment)
• Thermotherapy

Radiation Therapy

Radiation is used less frequently today but may still be appropriate in selected situations.

Enucleation

If the tumor is very large or vision cannot be preserved safely, removal of the eye (enucleation) may be recommended to save the child's life.

After enucleation:

• An orbital implant is placed.
• A custom prosthetic eye can provide an excellent cosmetic appearance.

What Is the Prognosis?

In countries with access to modern medical care, survival rates exceed 95%.

The outlook depends on:

• How early the cancer is diagnosed
• Whether it remains confined to the eye
• The hereditary status of the disease
• Response to treatment

Children with hereditary retinoblastoma require lifelong monitoring because of an increased risk of developing other cancers.

Living With Retinoblastoma

Families facing retinoblastoma often benefit from a multidisciplinary team that includes:

• Ocular oncologists
• Pediatric ophthalmologists
• Pediatric oncologists
• Genetic counselors
• Child life specialists
• Social workers

Support groups and advocacy organizations can provide additional education and emotional support.

Regular follow-up examinations remain essential, even after successful treatment.

Frequently Asked Questions

Is retinoblastoma curable?

Yes. When diagnosed and treated early, retinoblastoma has an excellent cure rate, with survival exceeding 95% in developed countries.

Is retinoblastoma inherited?

Approximately 40% of cases are hereditary and related to mutations in the RB1 gene. Genetic testing can help determine whether a child has the inherited form.

Can children keep their vision?

Many children retain useful vision, particularly when tumors are detected early and treated promptly. The amount of vision preserved depends on the size and location of the tumors.

More Information

For additional patient information, visit the American Society of Retina Specialists Retinoblastoma Page.

References

• American Society of Retina Specialists (ASRS) – Retinoblastoma
• National Cancer Institute – Retinoblastoma Treatment
• National Eye Institute – Retinoblastoma
• EyeWiki – Retinoblastoma
• American Cancer Society – Retinoblastoma