Does Retinoblastoma Cause Blindness?

Retinoblastoma can lead to blindness, but the majority of patients do not experience vision loss.

Retinoblastoma is a cancer of the eye that begins in the retina. The retina is the light-sensitive lining inside the eye. Retinoblastoma most commonly affects young children and rarely occurs in adults.

Retinoblastoma and vision: Retinoblastoma can affect vision and even lead to blindness. However, with early diagnosis and treatment, vision can be preserved in 70% to 80% of cases.

The survival rate of retinoblastoma: The 5-year survival rate for children with retinoblastoma is 96%. Usually, nine out of 10 children with retinoblastoma can be cured. The survival rate depends on whether the cancer has spread from the eye to other parts of the body. The long-term survival rate is much higher if the tumor has not spread beyond the eye.

Since retinoblastoma usually affects infants and small children, they are usually unable to explain their symptoms. The following signs in the child can indicate retinoblastoma

• A white area in the pupil (the dark circular portion within the iris, the colored part of the eye), is seen when a light is shone over the eye or while taking a flash photograph.
• The eyes appear to be looking in different directions (lazy eye or strabismus).
• Redness of the eye
• Swelling of the eye
• Eye pain
• Bleeding in the front part of the eye
• Eye bulging
• Iris color is different in the two eyes

Retinoblastoma occurs when there are genetic mutations of the nerve cells in the retina. The mutations cause the cells in the retina to grow and multiply rapidly. These cells accumulate forming a tumor. Retinoblastoma cells can invade into the eye and destroy the structure of the eye. The structures around the eye get damaged by tumor invasion. The tumor can spread to other parts of the body (metastasis) and can involve the brain and spine. The exact cause of the genetic mutations causing retinoblastoma is unknown, but it's most likely inherited.

Hereditary retinoblastoma is an autosomal dominant genetic disorder that is inherited. This means either one of the parents needs to pass on only a single copy of the mutated gene  to increase their child’s risk of retinoblastoma. If either one of the parents carries a mutated gene, there is a 50% chance that the child will inherit the gene. Though the genetic mutation increases a child's risk of retinoblastoma, it doesn't mean that the child would definitely develop cancer. Hereditary retinoblastoma usually occurs in both eyes. Children who inherit hereditary retinoblastoma may be at risk of developing other cancers.

The treatments for retinoblastoma depend on the size, location and extent of the tumor as well as the overall health of the patient. Treatment options include

• Chemotherapy: Chemotherapy is a medical treatment that uses medication to kill cancer cells. They may be taken orally or intravenously (IV). Chemotherapy is also beneficial for tumors that have spread beyond the eyeball or to other parts of the body. Intravitreal chemotherapy is a type of chemotherapy where the medications are directly injected into the eyes.
• Radiation therapy: Radiation therapy involves using high energy radiation beams, such as X-rays and protons, to kill cancer cells and shrink the tumor.
• Laser photocoagulation: In this therapy, a laser is used to destroy blood vessels. This cuts off the supply of oxygen and nutrients to the tumor, killing the tumor cells.
• Cold treatments (cryotherapy): Cryotherapy involves using a substance, such as liquid nitrogen, at an extremely low temperature to freeze and thaw the cancer cells repeatedly to kill cancer cells.
• Surgery: Large tumors that can’t be treated by other methods require surgery. Surgery for retinoblastoma includes
  • Enucleation: This surgery involves the removal of the affected eyeball. A part of the optic nerve, which is the nerve extending from the back of the eye and into the brain, is also removed.
  • Surgery to place an eye implant: Immediately after enucleation surgery, the surgeon places a special implant made of plastic or other materials in the eye socket. The eye implant is connected to the muscles around the eye that control eye movement. The implant does not provide vision but moves like a natural eye. 
  • Fitting an artificial eye: A few weeks after surgery and as the eye heals, a custom-made artificial eye is placed over the eye implant, which matches the healthy eye. The artificial eye is clipped onto the eye implant. The artificial eye moves like the natural eye. Vision is not restored but most children adapt to having vision in only one eye without any significant discomfort.