Page contents
- What is retinitis pigmentosa?
- symptoms
- Causes and risk factors
- Multiples
- Diagnosis
- treatment
- protection
Retinitis pigmentosa was given the name retinitis pigmentosa more than a hundred years ago for a disease in which pigmented spots appeared at the base of the eye, seen by ophthalmoscope.
The prevailing belief was that the discussion revolved around inflammation, and it became clear during the 20th century that the disease was hereditary and resulted from a genetic defect, and it became clear that the disease develops more blindness with age than any other genetic disease.
There are a range of genetic mutations that may cause the disease, but only a portion of them are less than ten known to this day.
Retinitis pigmentosa is a rare disease and the prevalence of the disease in the United States is approximately 1 in 2,700 people.
The retina contains two types of light-gathering cells: rods and cones. The rods are located around the outer ring of the retina and are active in dim light.
Most forms of retinitis pigmentosa affect the canes first, causing blurred night vision and inability to see sideways.
The cones are located mostly in the center of the retina, and they help to see color and fine details, when the disease affects them, the patient slowly loses central vision and the ability to see colors.
Symptoms of retinitis pigmentosa
The initial symptoms of the disease generally begin to appear in early childhood, and the most prominent symptoms associated with the disease are the following:
1. Loss of night vision
Signs of problems with night vision can be observed in children at the age of five, and night blindness is a general, universal and absolute symptom of the disease.
Night blindness occurs when the patient cannot see anything in the dark. His vision may be normal during the day, but the patient begins to lose night vision, and it takes longer to adapt to the darkness.
You might stumble on things, have trouble driving at night, and have trouble seeing in movie theaters or other darkened rooms.
2. Gradual loss of peripheral vision
This vision is known as tunnel vision. You may find that you bump into things as you move, because you are unable to see things below, or around you.
3. Loss of central vision
Some people also have problems with central vision, and this can make it difficult to do detailed tasks, such as reading or sewing a needle.
Reducing the field of vision is common, with 94% of patients complaining of this. In contrast, the effect on the sharpness of the central vision is very diverse.
There are patients with retinitis pigmentosa whose central vision is not affected until an advanced generation, on the other hand, there are those who lose their ability to central vision in the third decade of their lives.
The visible signs in the eyes change according to the duration of the disease. There are no prominent signs in the first decade of life in general, and in the second decade, light-colored spots and spots appear in the depth of the retina, and black pigment points in the retina itself.
Subsequently, retinal atrophy and pigmentation appear in the form of osteoblasts characteristic of the disease.
Causes and risk factors for retinitis pigmentosa
There are many causes and factors that lead to retinitis pigmentosa, and more than 60 genes are responsible for the formation of more than one type of disease that is transmitted during childhood in the following ways:
1. Autosomal recessive RP
In this case, both the mother and the mother have one gene that contains the disease, but it does not cause them to have any symptoms, but when a child is born who inherits both copies of the affected genes from the parents, this causes the disease and its symptoms to appear on it.
Since every child needs two copies of the affected gene for the disease to develop, the disease incidence rate for each child here is equal to 25%.
2. Autosomal dominant RP
In this case, the child needs to have one copy of the affected gene for symptoms of the disease to appear on him, and the probability of any child being infected in this case is equal to 50% of the possibilities.
3. A gene carried on the X chromosome (X linked gene)
The disease may be related to sex when the mother is completely healthy but transmits the disease to her male children, and mothers may have very mild symptoms in a percentage of one out of 5 infected women.
Most males who inherit the gene from their mothers have severe symptoms, and in this type of disease-causing gene, fathers do not pass the disease to their offspring.
Complications of retinitis pigmentosa
The most common complications of retinitis pigmentosa include:
- Cataracts at an early age.
- Retinal swelling.
Diagnosis of retinitis pigmentosa
The doctor can tell the patient about the presence of retinitis pigmentosa after looking into the eye and ordering the following tests:
1. Ophthalmoscope
The doctor puts drops in the eye to make the pupil wider so he can get a better look at the retina, and uses a portable instrument to look at the back of the eye.
If a patient has retinitis pigmentosa, certain types of dark spots will appear on the retina.
2. Visual field test
In this test, the patient looks through a device placed on a table at a point in the center of the vision, and while staring at that point objects or lights will appear on the side, the patient will press a button when they see them, and the device will create a map of the area of the side that can be seen.
3. Electroretinogram
An ophthalmologist places a gold foil film, or a special contact lens, on a patient's eye, then measures how the retina responds to flashes of light.
4. Genetic test
A DNA sample is sent to see what retinitis pigmentosa looks like in the patient.
Retinitis pigmentosa treatment
There is no cure for the disease so far. Since the beginning of the 20th century, dozens of failed experiments have been conducted to treat the disease, beginning with placenta implants in the eye socket conducted by a professor named Filatov in Russia, and ending with a series of treatments that have not yet proven effective. cause damage.
1. Treatments to delay vision loss
On the other hand, there are types of scientifically-referenced treatments that reduce the risk of vision loss, namely:
- Acetazolamide
In the later stages of the disease, the small area in the center of the retina can swell, called macular edema, and this can reduce vision.
Acetazolamide can reduce swelling and improve vision.
- Treatment with Vitamin A
High doses of vitamin A may help prevent disease progression, but be careful, large amounts of vitamin A can cause toxicity, so follow your doctor's instructions about the exact amount to be used.
- wear sunglasses
To reduce sensitivity to light, and protect the eyes from the sun's ultraviolet rays that may cause vision loss.
- Retinal implant
If the patient has late stages of retinitis pigmentosa, this qualifies him for a retinal transplant that provides partial vision.
2. Treatments under study
Serious research continues for the treatment of retinitis pigmentosa, or a way to truly improve vision impairment, and is currently taking three different directions:
- Replacing the affected gene: The replacement process develops by attaching a substance to the healthy gene and injecting them both into the eye or into the blood, so that it spreads throughout the body.
- Cultivation of embryonic cells inside the eye: with the aim of replacing infected cells.
- Implanting an electronic chip in front of or behind the retina: the chip absorbs light and transmits stimulation to the optic nerve, bypassing the diseased retina.
There are good prospects for one of these trends to succeed in the coming years.
Prevention of retinitis pigmentosa
Counseling and genetic testing may help determine if your child is at risk of developing this disease.
smilesإخفاء