Retinitis pigmentosa is a genetically determined degeneration of the retina, in which the photoreceptors of the eyes gradually die, resulting in complete blindness in the late course of the disease. This phenomenon is often just one of several symptoms and, together with the respective accompanying symptoms, forms a whole symptom complex, such as Usher or Alport syndrome.
What is retinitis pigmentosa?
Retinitis pigmentosa is a genetic disease of the retina that causes retinal degeneration and is also known as Patermann ‘s syndrome or retinopathy of pigmentosa. The Dutchman Frans Donders documented the disease as early as 1855 and coined the term retinitis pigmentosa at the time. For what does huriez syndrome stand for, please visit biotionary.com.
However, since the term retinitis actually refers to inflammation and the disease as such is not related to inflammatory processes, ophthalmology later renamed the phenomenon retinopathy pigmentosa. Nonetheless, Donder’s original naming convention is still in use today. Around three million people worldwide suffer from retinitis pigmentosa, with adolescence and middle age forming the peak phase of the disease.
In the case of genetically determined retinal degeneration, general vision deteriorates bit by bit over several decades. About half of all patients develop cataracts at a later stage, which is accompanied by a general clouding of the lens. The disease also occurs in animals and is called progressive retinal atrophy by veterinary medicine.
Causes
Retinitis pigmentosa is a genetic defect. More than 40 different genes can trigger the disease. In the meantime, medicine assumes a monogenetic inheritance for the transmission of the gene defect, i.e. several genes do not have to be defective, but the defect of a single one of those identified so far can already trigger the disease. The disease can be passed on in the autosomal dominant as well as in the autosomal recessive and gonosomal inheritance.
In addition to heredity, a spontaneous mutation can also cause the pathological defect in one of the more than 40 identified genes. Under certain circumstances, toxic phenomena caused by substances such as chloroquine can be accompanied by the same symptoms as retinitis pigmentosa. In this case, however, the physician speaks more of pseydoretinitis or phenocopy.
Symptoms, Ailments & Signs
An early symptom of retinitis pigmentosa is night blindness. Due to the gradual destruction of photoreceptors, the eyes are less able to adapt to changing light conditions over the course of time and are increasingly sensitive to glare. Later, contrast vision and color vision become impaired.
In the late course, most patients also suffer from an impairment of the field of vision in the form of what is known as tunnel vision. The central field of vision usually remains for a long time. However, complete blindness can occur late in the course. For almost a quarter of patients, retinitis pigmentosa is not the only phenomenon, but is accompanied by many additional symptoms and thus has the effect of an entire syndrome, such as Usher syndrome.
In this context, the doctor also speaks of an associated retinopathy pigmentosa, which can be accompanied by hearing disorders, paralysis or cardiac arrhythmia or muscle weakness. In addition to Usher syndrome, Alport and Refsum syndrome are among the best-known complexes in connection with associated retinitis pigmentosa.
Diagnosis & course of disease
The diagnosis of retinopathy pigmentosa is made using an electroretinogram. This electroretinogram enables the diagnosis to be made in early childhood. The earlier the diagnosis is made, the better the prospects of being able to deal with the disease in the later stages.
The prognosis depends heavily on which of the more than 40 causative genes is affected by the defect, with the disease being considered incurable to date, with the exception of the special form of Refsum syndrome. In order to assess the exact localization of the gene effect and to be able to make a prognosis, the doctor first analyzes all additional symptoms and in the course of this gets an impression of hearing disorders and blood values, for example. A DNA analysis can only be carried out once the exact gene defect has been identified.
Complications
Retinitis pigmentosa is a hereditary disease of the retina, which always leads to blindness via night blindness, limitation of the field of vision and visual acuity. There is currently no therapy that promises a cure. Vitamin A can possibly slow down the progression.
Additional complications occur in those forms of retinitis pigmentosa in which other organs of the body are also affected by symptoms of the disease. This is the case for about 25 percent of all those affected. Depending on the syndrome present, hearing problems, paralysis, muscle weakness, cardiac arrhythmia or mental development disorders can also occur.
Sometimes there are other changes inside the eyes, such as calcium deposits in the optic nerve, astigmatism, linden opacity, short-sightedness or vascular diseases. In addition to retinitis, Usher syndrome also has a severe hearing impairment, which is mainly due to damage to the hair cells. Retinitis pigmentosa also occurs in the context of Laurence-Moon-Biedl-Bardet syndrome.
In addition to retinal inflammation, diabetes mellitus, high blood pressure, obesity, muscle weakness, hearing loss, mental disabilities and motor disorders occur here. Cardiovascular problems can occur as a result of diabetes and high blood pressure. In other associated forms of retinitis pigmentosa, cardiac arrhythmias can also occur, sometimes leading to life-threatening complications. Gait disorders also result in further complications, which can often cause falls. Sometimes neurodegenerative disorders such as dementia development also occur with retinitis pigmentosa.
When should you go to the doctor?
Retinitis pigmentosa must always be evaluated and treated by a doctor. This disease cannot heal itself and, in the worst case, the affected person can become completely blind. The earlier the disease is recognized and treated, the higher the chance of a complete cure.
A doctor should be consulted if the patient suffers from night blindness. Those affected can hardly see or recognize anything at night. The ability to see different colors can also be affected by retinitis pigmentosa and should be examined by a doctor. However, those affected also suffer from hearing problems or heart problems as a result of the disease. If these symptoms occur, a doctor must be consulted.
First and foremost, retinitis pigmentosa is treated by an ophthalmologist. The other complaints can then also be treated by a cardiologist or an ENT doctor. Whether a complete cure can be achieved cannot generally be predicted.
Treatment & Therapy
The progression of retinopathy pigmentosa cannot be stopped for most forms of the disease. However, according to clinical studies, dietary supplementation with vitamin A in combination with hyperbaric oxygen therapies should be able to slow down the progression. Dealing with the disease is currently the focus of therapy.
For example, the patients should be better prepared for the possibly imminent loss of sight through psychological care and the early introduction to orientation techniques for the blind. Refsum’s syndrome is an exception because it is actually a metabolic defect whose progression can be halted by a special diet low in phytanic acid.
For all other forms, experiments are currently being conducted with stem cell therapies and the exchange of defective genes directly in the retina. In order to repair existing damage to the retina, medicine is currently also working on the development of retina implants that are intended to compensate for the loss of function of the photoreceptors. A subretinal implant with 1500 diodes should make it possible to see again in the future.
Prevention
Retinitis pigmentosa cannot be prevented because the disease is a genetic defect.
Aftercare
In most cases, those affected with retinitis pigmentosa only have a few and only limited options or measures for aftercare. First and foremost, a doctor should be consulted very early on, so that there are no complications or other symptoms later on. This is crucial for the further course of the disease, so a doctor should be contacted at the first signs and symptoms of the disease.
Retinitis pigmentosa is usually treated by taking various medications, with antibiotics in particular being used. Regular intake with the correct dosage should always be observed, whereby antibiotics should not be taken together with alcohol. In many cases, the support and help of one’s own family is also necessary to prevent depression or mental upsets.
In the case of children, it is above all the parents who must ensure that medication is taken correctly and regularly. A general course cannot be predicted, although in some cases the life expectancy of those affected may be reduced.
You can do that yourself
The retinal disease retinitis pigmentosa is hereditary and currently not curable. Due to the death of the retinal cells, the affected person’s field of vision is restricted. Spatial vision is lost. Walking with the cane replaces spatial orientation for him.
On the other hand, RP sufferers with tunnel vision are often still able to read with a magnifying glass. The cones located in the center of the retina are responsible for this. They are functional longer than the rods, which enable night and twilight vision. If these died, the affected person is dependent on the help of an accompanying person.
It is important that outsiders are made aware of progressive and worsening blindness. Wearing the blind badge ensures clarity. Aids such as Braille or voice-controlled computers make everyday life easier for those affected. The high sensitivity to glare is reduced with tinted glasses. If the contrasts become blurred and contours in the apartment can no longer be perceived, the affected person can use markings that he can feel with his hands. Color markings, on the other hand, are not suitable because color vision is also impaired.
Persons affected by RP are entitled to a severely handicapped pass.
If the patient has a well-developed visual center, a chip can be implanted in him, with the help of which he can recognize the contours of objects again.
