Retinoblastoma is the most common type of eye cancer. It is a malignant growth of retina of eye. Almost 90 percent of cases occur in children below the age of 5 years. Retinoblastoma is a painful eye tumor. The tumor originates from the cells of retina. Retina is a thin light sensitive layer in the posterior segment of eye. It is made up of millions of cells. The function of retina is to convert the light focused from lens on it into nerve signals and send it through the optic nerve to brain where an image is formed.
The exact cause of retinoblastoma remains unknown, but gene mutation is suspected to be the underlying reason of its occurrence. Most of the time retinoblastoma remains undetected in its initial stage. Leucocoria (white pupil reflex) is the hallmark symptom of retinoblastoma, followed by other symptoms such as painful eye, loss of vision, swelling of the eye, eye appear to project out and looking in different direction etc.
Till recently, the treatment outcome of retinoblastoma remained poor. But with advent of chemotherapy, radiotherapy, photocoagulation therapy, the prognosis is far better even in advanced cases of the disease.
What Causes Retinoblastoma In Babies?
Retinoblastoma develops when the cells of retina start growing uncontrollably and become cancerous. This occurs due to mutation of gene that controls cell division of retina. Chromosomes are present in each and every cell. They carry the specific genetic information. Chromosome 13 controls cellular division of retina. In children suffering from retinoblastoma, control over cell division remains unchecked, because of absence of chromosome 13 or some defect in it. This leads to uncontrolled cell growth and transforms into a tumor.
In at least 50 percent of cases there is no family history of retinoblastoma. This means it occurs sporadically. In rest half mutation is seen in family members. If mutation is present in a person, there is most likely risk of his children suffering from retinoblastoma.
Most children who have gene mutation tend to develop tumor between the age of 2 years and 5 years. However, it can also develop at younger age. Hereditary retinoblastoma involves both eyes. If there is no heredity influence often only one eye is affected.
Signs And Symptoms Of Retinoblastoma
Retinoblastoma can affect one or both the eyes. Leucocoria is the most characteristic presenting symptom of retinoblastoma. It is a white spot in the pupil of the eye. Pupil is the dark center circle in the middle of the eye. The pupil color becomes white when a flash of light is shone on it. Just as you see when a photograph flash light appears on the pupil. Sometimes this symptom is also referred as cat eye reflex.
Other important symptoms include:
- Loss of eye alignment. The eye may turn laterally towards ears or medically towards nose.
- Retinoblastoma produces severe pain in eye.
- Redness in eye.
- Patient has poor vision.
- Inflammation of the orbit.
- Dilated pupil with a flash of white spot.
Diagnosis And Treatment For Retinoblastoma
There may be delay in diagnosis of the first child because the parents are not aware, but in subsequent births parents become extremely cautious and they may look out for any serious or abnormal sign of retinoblastoma. After thorough physical and eye examination, the ophthalmologist may proceed with certain tests. Such test includes; bone marrow biopsy, examination of cerebrospinal fluid, CT scan and MRI of head, ultrasound test of the eye. Genetic testing is important to know whether the child has inherited the disease.
The aim of treatment is to save life and preserve his vision. Early diagnosis and treatment is effective in treating the disease to large extent. Treatment of retinoblastoma will also depend on the size of tumor and its location and whether it has spread to other organs of body. It also depends whether one eye is affected or both the eyes are affected. Treatment options are:
- Chemotherapy helps to kill the cancer cells in the tumor.
- Radiation is used for large as well as small tumors.
- Laser therapy is generally meant for small sized tumor.
- Cryotherapy
- Thermotherapy
The eye may be needed to be removed if the cancer is not responding to various treatment modes