Retinoblastoma in the eye: treatment, symptoms, causes
The retinoblastoma popularly often called «cancer eye.» This tumor occurs predominantly in children and is found in the age of five years. Retinoblastoma is a malignant tumor, the source of which can be any layer of the retina. It is capable of hitting choroid, optic nerve, tissue of the orbit, and with the progression gives distant metastases.
Among patients with the same number of boys and girls, the peak incidence occurs at 2-3 years. The tumor is a typical example of a hereditary cancer gene mutation which is responsible for the disease are well known. All tumors of child age on the proportion of retinoblastoma accounts for up to 5% of cases.
The human eye begins to form at early stages of fetal development, when the cells retinoblastoma, capable of rapid division. Subsequently, retinoblastoma give rise to cells of the retina is a very important component of the eye that allows us to see. If at some stage in the formation of the tissues of the visual analyzer fails, retinoblastoma will not become Mature cells, and will continue their reproduction and turn into a tumor.
There is a clear genetic predisposition to this tumor type. Parents who were ill in childhood retinoblastoma was successfully treated, are seldom born healthy children. More than half of all cases of congenital disease is neoplasia, which is often combined with other malformations (heart defects, cleft palate, etc.). Usually the tumor is detected in the first two or three years of baby’s life. In addition, these children have an increased risk of other malignant tumors.
Retinoblastoma, a malignant being, nevertheless, well is treatable, especially in the early stages, when you can save not only the eye, but also vision, so the vigilance of parents in the presence of familial cases of retinoblastoma plays an important role in the timely diagnosis and treatment.
Causes of retinoblastoma
Among the risk factors of the tumor can be distinguished:
- Heredity and genetic mutation (usually in the 13th chromosome pair);
- The age of the parents;
- The adverse impact of environmental and occupational hazards (metallurgical industry, in particular), experiencing parents or the woman during pregnancy.
Causes of retinoblastoma typically rooted in genetic anomalies, often inherited from parents to children. Hereditary form of retinoblastoma is characterized by the vast majority of cases a bilateral lesion, while retinoblastoma, caused by other reasons, usually affects only one eye. The hereditary tumor is detected early, in the first two or three years of a child’s life. As a rule, parents who know about this kind of disease or had it, carefully watching the development of the eye in children and to promptly visit an ophthalmologist.
Retinoblastoma is not associated with heredity, usually unilateral and can be discovered at any age, although in adults, this pathology is extremely rare. Such cases are not familial, but the reason for them lies in spontaneous mutations of individual genes.
The older the parents and the more external influences they experience from the environment either by working in harmful or dangerous production, the higher the probability of occurrence of retinoblastoma in the offspring.
The tumor may form a single center of growth or several (with a hereditary variant of retinoblastoma), to grow inside the eye, affecting the retina and vitreous body, or outward (exophytic), causing retinal detachment and accumulation of exudate behind her. Possible and infiltrative growth with the defeat of all layers of the body.
The cells that comprise the tumor, pleomorphic, intensely divided, as evidenced by the significant number of pathological mitoses. Tissue tumors are frequent necrosis, deposition of calcium salts. The degree of cell differentiation of retinoblastoma involves the allocation of differentiated and undifferentiated forms of the tumor, which affects the course of the disease.
Gradually increasing, retinoblastoma can go beyond the retina and eye tissues, to penetrate into the optic nerve and the elements of the orbit. Like any other malignant tumor, retinoblastoma can give metastases to the brain, bones, liver.
Symptoms and stages of retinoblastoma
Symptoms of retinoblastoma depend on the size of the tumor, type of growth in relation to tissues of the eye, lesions of the structures of the orbit. Usually the first symptoms noticed by parents who travel with the baby to the doctor. The complexity of the refinement of symptoms often associated with what little children can’t talk or describe his complaints, but much of retinoblastom still manages to identify the early stages of development.
Signs of the tumor are reduced to:
Usually the tumor is detected when it has not yet left the border of the eye. The first symptoms are reduced to leukocoria and impaired vision.
Leukocoria is considered a very characteristic feature of neoplasia, which is due to the fact that tumor tissue is visible through the pupil and gives it the characteristic whitish glow. Usually leukokoria indicates a high amount of tumor that grows in the retina, goes beyond it and is able to shift the lens and vitreous body.
Small-sized retinoblastoma can manifest with loss of Central vision, loss of field of vision and even complete blindness. In children about the problems with vision may indicate strabismus, often it becomes the main early symptom of the disease since kids can not assess the degree of loss or impairment, or describe their symptoms.
The growth of tumors developing glaucoma (increased intraocular pressure), which is the cause of the pain, by itself, the retinoblastoma pain causes. Filling eye tumor tissue or retinal detachment lead to increased vascularity of the iris, resulting in excessive production of intraocular fluid as a consequence of glaucoma. To the signs of vision impairment or strabismus added to the pain. By increasing the volume of retinoblastoma and defeat it of the eye tissue develops blindness in children of the eye is increased in size, with metastasis of neoplasm, the condition progressively worsens, joined by symptoms of intoxication, vomiting, weight loss.
For isolated retinoblastoma: intraocular stage, when the tumor is restricted to the eyes, and vneglasnoe (extraocular). The second stage characterizes the progression of the tumor, accompanied by the release of her eye, involvement of the optic nerves and tissues of the orbit.
Severe disease and the likelihood of metastasis threaten the patient’s life. Especially dangerous is the germination of tumor tissue in the soft cerebral membrane and spread it over the surface of the brain.
Depending on the clinical features can distinguish four stages of retinoblastoma:
- The first stage describes a small tumor, manifested by leucocoria, possible blurred vision.
- In the second stage joins the secondary inflammation involving the choroid and iris, and of the possible symptoms of tearing, fear of light, redness of the eye. Increasing intraocular pressure leads to pain.
- In the third stage, the tumor leaves the eye and goes beyond it into the tissues of the orbit, paranasal sinuses of the skull, soft brain shell.
- The fourth stage is associated with metastases in bones, liver, Central nervous system and manifests itself by symptoms of General intoxication, weakness, weight loss, up to cachexia. Brain lesions and meninges, causes intense headache, vomiting.
For the diagnosis of retinoblastoma applies the whole range of ophthalmic examinations. In families where one or both parents suffered from retinoblastoma or were the cases of detection of this tumor with other relatives, it is necessary to provide young children with timely monitoring by an ophthalmologist. The appearance of leukocoria, strabismus, vision disorders are the warning signs, talking about the growth of the tumor, so the parents have noticed at least one of them, the child should immediately go to the doctor.
Eye examination includes:
If the tumor extends beyond the organ of vision, conducted radiographic studies of the orbit, paranasal sinuses, bone which can be destroyed by neoplasia. If necessary, the examination of complement CT or MRI of the region of the tumor, of the brain. In the case of suspected metastasis can be assigned a lumbar puncture in order to exclude lesions of the meninges, bone marrow study at a probability of intraosseous metastases.
Treatment of retinoblastoma includes the use of surgical approach, radiotherapy and chemotherapy. It’s quite effective and in 90% of cases it is possible to achieve a stable result patients. Most patients are able to preserve vision.
It is important to start treatment as early as possible, when the tumor is small and has not spread to the tissue of the orbit and the optic nerve. In some cases you can do without surgery. When choosing a method of therapy must be taken into account:
- The extent of the lesion (one eye or both, the involved tissue of the orbit and optic nerve);
- Preservation of vision or the possibility of recovery after treatment;
- Involvement of the orbit, brain and its membranes, and the presence of distant metastases.
There is a tendency to maximize the preservation of eye tissues at the expense of conservative therapy, which can be repeated in case of recurrence of the tumor. In children it is very important not only to preserve vision but also the eye itself, after growth of the facial skull after surgery to remove the organ of vision can be significantly impaired leading to severe cosmetic defects. The rational combination of methods of conservative therapy is possible only in the initial stages of the tumor. If you have a two-way defeat, the tactic is selected for each eye separately.
Among the gentle techniques used in retinoblastoma cryotherapy, phototherapy, thermotherapy. If the tumor affects the front part of the retina and less than 7 mm, then make the cryoablation of tissues of retinoblastoma. In case the location of the neoplasia in the back of the retina and the size is not more than 4 mm is shown photocoagulation. Thermotherapy involves the impact on the tumor by high temperatures due to the combination of ultrasound, infrared radiation and microwave exposure. These methods give excellent results in small formations, allowing you to save on vision and visual function.
Surgical treatment of retinoblastoma involves the removal of eyes (enucleation) or the eyes with the tissues of the orbit (exenteration). The indications for surgery are:
When you remove the whole eye it is important to cut the optic nerve as far as possible from the place of growth of the tumor, to eliminate the further spread of neoplasia. At the end of six weeks after surgery raises the issue of prosthetics. Of course, the complete removal of the affected organ gives the best effect in malignant tumors, but the possible cosmetic deformity and permanent loss of vision forced to look for ways to be more sparing treatment.
Another option is surgical removal of the tumor is exenteration of the eye. This operation is more traumatic than enucleation because it requires removal of not only the eyes but all of the tissues of the orbit including the periosteum. With the defeat of the century, they are also deleted. Prosthesis after this intervention impossible, and the testimony to it becomes a massive form of tumor that grow all the tissues of the orbit.
Radiation therapy is quite effective for retinoblastoma. It is widely used in Russia, but in Europe this method gives space to other non-invasive procedures. Radiation therapy is carried out both distantly and with the help of applications of radioactive substances. Local application makes it possible to reduce the dose of radiation, but the effect can be worse because of the uneven irradiation of eye tissues and high risk of radiation damage to the membranes of the eye. This method is used when smaller sizes of retinoblastoma located outside of the optic nerve. In congenital forms of retinoblastoma preferably external beam radiation, since the tumor usually grows at several points.
Remote radiation therapy allows to achieve a positive result more than 70% of patients, while if there is a possibility of the conservation of view, the preference is given to radiation, rather than enucleation. Radiation therapy may be used either alone or in combination with surgery or other conservative methods. Irradiation exposed the entire retina, vitreous body and at least 1cm of optic nerve, dose is usually high and reaches up to 4500 Gr.
Possible complications of radiation consider the risk of bleeding, radiation keratitis and cataracts. Since most patients are children up to 3 years, for their treatment it is necessary to conduct General anesthesia and the use of a special table that allows you to lock the child in the desired position.
Chemotherapy usually involves multiple drugs. The most common pattern is the combination of vincristine, carboplatin and Vepesid are finished. The indications for chemotherapy are the massive involvement of tissues of the orbit, germination tumor of optic nerve metastasis of retinoblastoma.
In developed countries, there is an increase in the number of retinoblastoma diagnosed in the early stages, so in some cases it is possible to do without surgery, removing a tumor with radiation therapy, photocoagulation or cryotherapy. The prognosis of retinoblastoma is considered to be favourable, especially for small tumors. Sustained recovery is likely with a significant amount of lesions of the orbit requiring exenteration of the eye, but no serious cosmetic defect significantly reduces the patient’s quality of life.
For the prevention of retinoblastoma important point is the genetic counseling of families in which there were cases of tumor. Children born to parents with an adverse family history or a history of once retinoblastoma must be under the constant supervision of an ophthalmologist. Timely detection of the tumor will allow to do without the surgery and save the child the ability to see.