A coloboma is a special form of clefting in the eye. Clefting is either congenital or acquired over the course of life. The coloboma affects either the iris or the iris, the choroid or the lid of the eye.
What is a coloboma?
Colobomas cannot be treated and can only be concealed cosmetically by wearing appropriate contact lenses. Associated visual field defects cannot be treated either. See AbbreviationFinder for abbreviations related to Coloboma.
A coloboma is a cleft in the area of the eye. The term comes from the Greek and means something like “mutilation”. The cleft is either present from birth or acquired later through various causes.
In the majority of cases, the term coloboma is used in the field of ophthalmology. For this reason, the exact name for the disease is ocular coloboma. In principle, the coloboma is inherited in some cases, while in other people the cleft develops later.
In a typical coloboma, the fissure appears in the form of a keyhole on the iris, specifically on the so-called inferonasal underside. In addition to the iris coloboma, there are also the eyelid coloboma, the papilla coloboma, the lens coloboma and a special coloboma at the back of the eye.
Causes
The potential causes of a coloboma differ primarily depending on whether the coloboma is congenital or acquired. In the majority of cases of congenital coloboma, an error in the development of the embryo has occurred. A cleft forms during the development of the eye.
This malformation is counted among the so-called inhibition malformations. Due to faulty controls, the eye cup gap does not close completely after the invagination is complete (medical term “invagination”). Normally, the eye sac closes to form the so-called eye cup.
In most cases, the optic cup fissure points nasally downwards in embryos. For this reason, congenital forms of iris coloboma often also point downward in the nasal direction. Depending on the individual cleft formation, one or more areas of the eye are affected by the malformation. The eye develops in the unborn child between the 4th and 15th week of pregnancy.
If the ocular fissure is not completely closed during this time, a coloboma forms. The clefting affects either one eye or both eyes. In addition, coloboma often occurs together with microphthalmia. This is an abnormally reduced size of the eyeball.
In many cases, the malformation that ultimately leads to the development of a coloboma is triggered by drugs or other chemical substances, for example. Above all, the substance thalidomide has proven to be particularly dangerous in this context. In addition, there are some hereditary factors that may promote cleft formation in the eye.
These include, for example, cat’s eye syndrome, trisomy 13, Charge’s syndrome, Cohen’s syndrome and Lenz’s syndrome. In addition, in some cases, clefting occurs as a spontaneous disturbance in the development of the eye. In many cases, however, the specific cause of a congenital coloboma remains unclear.
In some cases, for example, a mutation in the so-called Pax gene is responsible for the deformity in the eye. Inheritance in this case is probably autosomal recessive, autosomal dominant or X-linked. Because of this, colobomas tend to cluster in certain families. In principle, however, the formation of gaps tends to appear sporadically, whereby it can be assumed that various unexplained environmental conditions have an influence on the undesirable development.
In addition, in some cases, coloboma is associated with various other diseases or syndromes. These include, for example, various neurological or systemic developmental malformations, such as Klinefelter’s syndrome, Noonan’s syndrome, Hirschsprung’s disease and malformations of the skeleton.
Congenital colobomas occur at an estimated rate of 0.6 per 10,000 births. Consequently, it is a rather rare disease. On the other hand, acquired colobomas are the result of external violence in the majority of cases.
Such influences are possible, for example, in connection with surgical interventions on the eye or accidents. As a result, the gap forms in the iris, eyelid, or other area of the eye.
Symptoms, Ailments & Signs
If a coloboma is present, the affected persons suffer from various typical symptoms and complaints. In principle, vision depends on the severity of the cleft formation. Completely asymptomatic colobomas are therefore also conceivable.
Many affected patients suffer from too bright light because the ability of the iris to regulate is impaired. Large colobomas located on the optic nerve or retina may cause a visual field defect (medical term “scotoma”) or blurred vision. Rarely does coloboma cause blindness.
Diagnosis & course of disease
If persons suffer from characteristic symptoms, an appropriate medical specialist should be consulted. Colobomas are usually relatively easy to diagnose because they have a typical appearance. After discussing the medical history, the attending physician performs clinical examinations of the eye and tests the patient’s vision.
Complications
In most cases, the coloboma causes various symptoms or complications in the patient’s eyes. These complaints can restrict everyday life and the life of those affected and significantly reduce their quality of life. In the worst case, the affected person can go completely blind.
However, the extent of the eye problems depends heavily on the size of the coloboma and its severity. In most cases, there is a strong incidence of bright light, so the iris is damaged by this incidence. It can also lead to various paralysis and disorders of sensitivity in the face, which can also limit the everyday life of the person concerned.
Paralysis can become noticeable in the area of the mouth, so that the patient may be dependent on the help of other people in everyday life in order to be able to master it. However, life expectancy is reduced by a coloboma.
In many cases, loss of vision or total blindness leads to depression and other mental health problems. Unfortunately, a coloboma cannot be treated. If the complaint is purely cosmetic, the coloboma can also be removed. However, the paralysis in the field of vision cannot be treated.
When should you go to the doctor?
People who experience reduced vision after surgery or after taking certain medicines should consult their family doctor. People with cat’s eye syndrome, trisomy 13 and other hereditary diseases are also among the risk groups and should consult a doctor closely. A doctor’s visit is necessary if the symptoms do not go away on their own. If other symptoms such as a loss of visual field or eye pain appear, an ophthalmologist must be consulted.
In the event of complications such as blindness or paralysis in the mouth area, the person concerned is best taken to a hospital immediately. If there is an acute risk of falling, the coloboma must be examined and treated. Since causal treatment is not possible, the patient must visit a doctor regularly and adjust the medication. An optometrist should also be consulted. External flaws can be corrected with suitable contact lenses. Vision itself cannot be treated therapeutically. Nevertheless, vision must be checked regularly so that any worsening of the coloboma can be detected at an early stage.
Treatment & Therapy
Colobomas cannot be treated and can only be concealed cosmetically by wearing appropriate contact lenses. Associated visual field defects cannot be treated either.
Outlook & Forecast
The prognosis of the coloboma depends on the extent of the damage suffered and is therefore to be made according to the individual circumstances. First, it must be clarified whether the disorder is congenital or acquired. If the eye is congenitally abnormal, an operation is usually carried out in the first few weeks or months of life. Nevertheless, all symptoms can often only be fully clarified in the further course of development of the child. Of course, an infant cannot fully respond to questions and tests.
In the case of an acquired disorder in the course of life, a comprehensive diagnosis is easier and faster in most cases. The optical changes and abnormalities of the eye can only be changed by surgical intervention. Spontaneous healing is not to be expected with this disease. Cosmetic surgery comes with various risks and side effects. If an intervention proceeds without further complications, the gap formation has normally been optimized. However, visual impairments that have been suffered can only rarely be completely regenerated.
A large number of patients experience psychological stress due to coloboma. In addition to mood swings and changes in personality, secondary diseases are possible. If depression is also diagnosed, this must be taken into account when making the overall prognosis.
Prevention
Since colobomas are congenital in most cases, there are no effective measures to prevent the malformation. If typical symptoms occur, a doctor should be consulted.
Aftercare
Follow-up care is generally intended to prevent disease recurrence. However, this does not apply to a coloboma. The congenital or acquired cleft formation of the eye is permanent. Patients have to live with the typical symptoms such as visual field defects. They cannot be corrected. However, aftercare can provide tools of different types.
For example, some people suffer from mental health problems as a result of the disease. The impairment of vision can also cloud the meaning of life. With therapy, doctors can support those affected in their everyday lives and show them private and professional options. The cosmetic problem can still be solved with special contact lenses and glasses. This reduces elementary complications to a minimum.
Ophthalmologists recommend regular check-ups of the affected eyes. As a result, secondary diseases can be tackled at an early stage. A rhythm is agreed individually. Exposure to light can further damage the iris. As a result, blindness, retinal detachment or glaucoma are possible.
Furthermore, paralysis of the face has been demonstrated in certain people. Follow-up care is therefore aimed at stabilizing the disease – but without being able to tackle the actual cause. It is about long-term everyday support through which patients realize a large degree of independence.
You can do that yourself
Patients with a coloboma in the eye suffer from physical as well as psychological and cosmetic problems. The formation of a gap in the area of the iris, which is typical of a coloboma, is also noticed by other people and therefore often leads to insecurity or even inferiority complexes in the patient. These reduce the quality of life of those affected and, in the worst case, lead to depression. If people with coloboma are increasingly suffering from mental problems due to the visual abnormalities, they should consult a psychotherapist in their own interest.
In order to conceal the gap in the eye, special contact lenses are available, which at least visually hide the coloboma and thus make it invisible to other people. With regard to the physical complaints, it is mainly bright light that causes problems for the patient. In order to increase their own quality of life, special glasses are recommended, which patients wear regularly.
Conventional sunglasses with tinted lenses to reduce glare can be considered. Special glasses are also possible, which adapt their glass color to the brightness of the surrounding light and are a good choice for many sufferers. In severe cases, the coloboma results in visual field defects and blindness, which the patients come to terms with by taking appropriate measures such as care offers.
