Retinoblastoma is a cancer of the eye in children. It originates from the retina, the light sensitive layer, in eye. It is the commonest eye tumor of the eye in childhood. This tumor may involve one (75% of cases) or both (25% of cases) eyes in a child. Untreated, retinoblastoma is almost always fatal, hence the importance of early diagnosis and treatment
As the child does not complain of any poor vision, the tumor may remain undetected. The most common way of presentation is a white reflex (leukocoria) behind the pupil. This is sometimes called the cat's eye reflex. There may be other causes of this white reflex as well, but an evaluation by an ophthalmologist is a must in all these children to rule out the possibility of this serious and potentially life threatening disease. Other signs might be deviation of the eye, redness, and pain.
What causes retinoblastoma?
The gene associated with retinoblastoma causes the tumor only when it is not working properly. Humans have two copies of this “tumor suppressor” gene that protect them against retinoblastoma and other tumors in each cell in their bodies. When both copies of this gene stop or are prevented from functioning properly, this cancer develops.
Who is at risk?
Ninety percent of retinoblastoma patients have no family history of the disease and only 10 percent of newly diagnosed patients have other family members who are retinoblastoma survivors.
What are the most common signs/symptoms of retinoblastoma?
Common signs of retinoblastoma include:
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A white "glow" or "glint" in the pupil of one or both eyes in dim lighting
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White pupil in a color photo
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Crossed or misaligned eyes
What are the treatment options?
There are many treatment modalities for this tumor. Among them:
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Enucleation: This means removal of the eye. The space is replaced by an artificial implant made of plastic, rubber or coral. The child is fitted with prosthesis or artificial eye, made to match the other eye. This artificial eye, of course, does not have any vision.
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External beam radiation: as an alternative to enucleation, this method of giving radiation treatment to the eye may treat the tumor while preserving the eye. As the tumor is very radiosensitive, this treatment method is very effective. Though the radiation may cause damage to the surrounding structures of the eye, e.g., lens (cataract), lacrimal system (dry eye), orbit (bone maldevelopment) etc. It also increases the chance of developing secondary tumor of the bone, especially in children with tumor involving both eyes.
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Localized Plaque radiation therapy: This method involves applying radioactive plaque close to the tumor on the sclera, and thus gives the radiation therapy in a localized area. It significantly decreases the local complications associated with radiation therapy.
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Photocoagulation: Laser treatment for the tumor is effective and safe for tumors that are smaller in size. In the right cases, this treatment may help in preserving eye as well as the sight of the child.
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Cryotherapy: this involves freezing of the tumor by applying a special probe on the external surface of the eye (sclera). This treatment is done under direct observation and is effective in saving the eye and sight in patients with small tumor.
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Chemotherapy: Treatment with anticancer drugs. There has been a recent preference towards treatment with systemic drugs as an additional treatment. The chemotherapy may decrease the size of the tumor and thus make it more amenable to local treatment like laser, cryotherapy and plaque radiation.
Shekar Nethralaya has specialization in treating all types of pediatric eye diseases including retinoblastoma in Bangalore.