Retinoblastoma: Causes, Symptoms & Treatment

Retinoblastoma is a malignant, mutation-related retinal tumor that occurs primarily in young children and affects both sexes with equal frequency. If diagnosed early and therapy is started, retinoblastoma is curable in most cases (about 97 percent).

What is retinoblastoma?

Retinoblastoma (also glioma retinae, neuroblastoma retinae) is a malignant (malignant) retinal tumor that usually occurs in childhood and, less commonly, in adolescence and is due to a genetic or spontaneous somatic mutation of immature retinal cells. Retinoblastoma typically manifests itself by a so-called amaurotic cat’s eye, which is characterized by a pupil that lights up white under certain lighting conditions, as the tumor already fills most of the area behind the lens. In addition, unilateral or bilateral strabismus (squinting), pseudobuphthalmos (eyeball enlargement), and elevated intraocular pressure and chronic ocular inflammation are characteristic symptoms of retinoblastoma in some cases. As it progresses, retinoblastoma can grow into the optic nerve (optic nerve) and meninges (meninges) or cause retinal detachment, which can lead to visual loss (blindness).

Causes

Retinoblastoma is causally due to spontaneous somatic or genetic mutations of both alleles of the so-called retinoblastoma gene or tumor suppressor gene RB1 on chromosome 13. Tumor suppressor genes carry the genetic information to regulate cell growth. If such a gene is damaged by mutation processes, it loses its ability to regulate and uncontrolled growth of cells such as the retinal cells in retinoblastoma can occur. Inherited is usually a damaged allele and thus the disposition (predisposition) for retinoblastoma. For the regulatory ability to be switched off, both alleles of the tumor suppressor gene must be disrupted, i.e. the second allele must also mutate spontaneously. Since in this case all somatic cells are affected, retinoblastoma in this familial form usually occurs bilaterally. In contrast, in a purely somatic retinoblastoma, both alleles in a cell must mutate spontaneously at the same time for the disease to manifest. Therefore, retinoblastoma here usually occurs unilaterally.

Symptoms, complaints, and signs

Smaller retinoblastomas usually do not cause definite symptoms. A possible initial symptom is a white spot around the pupil. This so-called cat’s eye syndrome indicates extensive tumor growth inside the eye. It is usually a whitish-yellow discoloration that appears on one or both pupils. As a result of increased intraocular pressure, the affected eye may become swollen, red and painful. As the tumor grows and spreads to other areas of the eye, vision problems may occur. Sufferers then see double images, have a blurred perception of their surroundings or suffer from visual field loss. In extreme cases, blindness may occur in one or both eyes. In addition to impaired visual acuity, one in four patients also suffers from strabismus. With further extension of the retinoblastoma, protracted ocular inflammation may occur. In addition to an increase in intraocular pressure, such an inflammation also causes severe pain and other signs of inflammation (such as fever and malaise). An advanced retinoblastoma can lead to detachment of the retina and thus to loss of vision. If the tumor in the eye is treated in time, complete recovery is possible. In a majority of cases, vision can be preserved and signs of inflammation decrease after a few weeks. Retinoblastoma that is left untreated can be fatal.

Diagnosis and progression

Retinoblastoma is usually diagnosed in infancy on the basis of the amaurotic cat’s eye and during ophthalmoscopy (reflection of the back of the eye). Imaging techniques (sonography, magnetic resonance imaging, computed tomography) can be used to determine the extent of the retinoblastoma into the surrounding tissue structures. To determine the familial form of retinoblastoma, blood analyses of the affected child as well as his or her family members (parents, siblings) are performed.If diagnosed and treated early, the prognosis for retinoblastoma is good and the affected eye usually heals completely, preserving vision. If left untreated, retinoblastoma has a lethal course. In the familial form, additional retinoblastomas and various secondary tumor types (especially bone tumors) may occur after successful therapy.

Complications

In most cases, retinoblastoma can be cured. Especially if diagnosed and treated early, most cases have a positive course of the disease and no particular complications. In this disease, the affected person primarily suffers from a white upright of the pupil. This leads to considerable visual complaints and also to restrictions in the daily life of the affected person. Strabismus can also be promoted by the disease, which can lead to bullying or teasing in young people. Furthermore, if left untreated, retinoblastoma leads to inflammation in the eye and, in the worst case, to complete loss of vision. Especially in young people, vision loss can lead to severe psychological discomfort or even depression. These complaints can be easily avoided by regular eye examinations. Retinoblastoma can usually be removed relatively easily. There are no complications and vision is preserved. In severe cases, however, the entire eyeball must be removed and replaced with a prosthesis. The life expectancy of the affected person is usually not negatively affected by retinoblastoma.

When should you see a doctor?

Because retinoblastoma is a tumor, it must always be examined and treated by a physician. It does not heal itself and, in the worst case, the tumor may spread throughout the body. However, retinoblastoma can be treated relatively well if it is diagnosed early. A doctor should be consulted if the affected person suffers from swelling in the eye. In this case, the internal pressure of the eye is also significantly increased, so that visual complaints can occur. In this case, the affected person suffers from double vision or veil vision. Some sufferers also have strabismus. Since retinoblastoma also affects the entire body, this disease can cause fever or even pain in the eye. If these symptoms occur over a longer period of time and do not disappear on their own, a doctor must be consulted in any case. Retinoblastoma is usually treated by an ophthalmologist.

Treatment and therapy

The specific therapeutic measures for retinoblastoma depend on the stage of the tumor disease. For example, smaller retinoblastomas can be treated with radiation therapy by applying radioactive iodine or ruthenium directly to the tumor cells during a surgical procedure to specifically kill them. Laser therapy destroys the vessels supplying the tumor, causing the tumor to die. In addition, thermo- or cryotherapeutic measures are used to kill the tumor cells of a small retinoblastoma as a result of heat or icing. With the aforementioned therapeutic measures, vision can usually be preserved. If a retinoblastoma is already in an advanced stage of growth and there is damage to the affected eye, enucleation (removal of the eyeball) is necessary to prevent metastasis. The removed eyeball is replaced with an ocular prosthesis after the surgical procedure. If both eyes are involved, an attempt is usually made to preserve the vision of one eye by performing enucleation in the eye affected with the larger tumor, while the other eye is treated with laser, radiation, or cryotherapy. If the optic nerve (optic nerve) is already affected and/or metastasis is detectable, additional chemotherapeutic measures are used for retinoblastoma.

Prevention

Retinoblastoma cannot be specifically prevented because the triggering spontaneous mutations cannot be controlled. If there is a family history of eye cancer and symptomatic signs, the child should be examined by an ophthalmologist to diagnose and treat potential retinoblastoma early. Furthermore, pediatric screening examinations should be used for early detection of retinoblastoma.

Aftercare

After the initial treatment of retinoblastoma, follow-up examinations take place at regular intervals. For this purpose, the patient must attend a clinic. Attending the follow-up examinations is exceedingly important. There is a risk that the retinoblastoma will recur and need to be treated accordingly. Possible secondary and concomitant diseases may also need to be treated. The most important goal of retinoblastoma follow-up is the early detection of a recurrence. The sooner the new tumor is diagnosed, the better it can be treated. The same applies to concomitant or secondary symptoms that may occur due to the disease. If psychological or social problems exist due to the retinoblastoma, the aftercare also takes care of them. As part of the follow-up examinations, the eyes and eye sockets of the affected child are regularly checked. This involves an ophthalmoscopic examination under anesthesia. How many follow-up examinations ultimately have to take place depends on the type of therapy, the age of the child and the genetic findings. If the retinoblastoma has hereditary causes, regular follow-up examinations are performed at three-month intervals after the surgical intervention until the child is 5 years old. These examinations take place in a special center. If chemotherapy with other forms of treatment such as surgery, kyrotherapy, laser therapy or radiotherapy must take place, the examination is usually performed every four weeks. This procedure usually allows early detection of neoplasms of retinoblastoma.

What you can do yourself

Retinoblastoma initially requires close medical treatment. Accompanying this, various self-help measures are available to support the medical therapy. Basically, retinoblastoma is a condition that requires medical treatment. The self-help measures focus on staying physically active and maintaining a gentle diet. The child also needs assistance with daily living. Due to impaired vision, many activities are no longer possible without assistance. After eye surgery, the patient must not expose the eye to direct sunlight or other stimuli. The doctor’s instructions regarding wound care must be strictly adhered to so that no infections occur. Since this is a serious cancer, the affected children and adolescents often suffer emotionally as well. Parents should spend as much time as possible with the sick child and obtain child-friendly information about the disease. Discussions with specialists help the child to better understand the condition. Therapeutic counseling can also be useful for the parents. If the course of the disease is positive, the healthy and active lifestyle should be maintained in the long term. In addition, the child usually needs a visual aid, which should be organized at an early stage. Any external changes can be treated with make-up or prostheses. The Children’s Cancer Foundation provides guidance to affected families.