Maintaining good vision until old age is very difficult. Often in old age, the ability to see is gradually lost. This is due to the fact that all human organs begin to “wear out” over time. One of the first to suffer is eye tissue. It is believed that vision deteriorates from the age of 40-45. This happens even in cases where a person previously had no problems with vision throughout life. Visual impairment occurs gradually. Most people are concerned about “farsightedness,” that is, the inability to see objects close by. Sometimes, more serious problems develop. These include pathologies such as cataracts, glaucoma, etc. Age-related macular degeneration is considered another common disease. Such an ailment is dangerous in that it can lead to loss of vision.
The concept of age-related retinal degeneration
Age-related macular degeneration (AMD) is a pathology that develops due to dystrophic processes in the retina of the eye. This area is directly connected to the brain (it is a peripheral analyzer). With the help of the retina, the perception of information and its transformation into visual images is formed. On the surface of the peripheral analyzer there is a zone that contains many receptors - rods and cones. It is called a macula (yellow spot). The receptors that make up the center of the retina provide color vision in humans. In addition, it is in the macula that the focusing of light occurs. Due to this function, a person’s vision is clear and precise. Age-related macular degeneration of the retina leads to dystrophy of macular tissue. Not only the pigment layer undergoes changes, but also the vessels that feed this area. Despite the fact that the disease is called “age-related macular degeneration”, it can develop not only in older people. Often the first symptoms of pathological changes in the eye begin to be felt by the age of 55. By old and senile age, the disease progresses to such an extent that a person can completely lose the ability to see.
Age-related macular degeneration of the retina is a common ailment. Often this pathology becomes the cause of disability and disability. It is widely distributed in America, Asia and Europe. Unfortunately, the disease is often diagnosed in the later stages. In these cases, you have to resort to surgical treatment. However, with timely therapeutic treatment, as well as the implementation of preventive measures, it is possible to avoid surgical intervention and complications of pathology (blindness).
Causes of age-related macular degeneration
Like all degenerative processes, this disease tends to a slow and progressive course. The causes of dystrophic changes in the macula of the retina may be different. The main one is the involution of eye tissue. Nevertheless, in some people, dystrophic changes occur faster, while in others - more slowly. Therefore, there is an opinion that age-related macular degeneration is inherited (genetically), and also prevails among people of European nationality. Other risk factors include: smoking, hypertension, and frequent exposure to the sun. Based on this, we can identify the causes of macular degeneration. These include:
- Vascular lesions. Atherosclerosis of the small arteries is considered one of the risk factors. Disruption in the delivery of oxygen to the tissues of the eye is one of the main mechanisms for the development of degeneration.
- Overweight.
- Lack of vitamins and certain trace elements. Among the substances necessary for maintaining retinal tissues, there are: lutein and zeaxanthin.
- The presence of a large number of "free radicals." They increase the risk of developing organ degeneration several times.
- Ethnic features. The disease is more common in people with light-colored eyes. The fact is that among the representatives of the Caucasian race, the density of the pigment contained in the retina is low. For this reason, dystrophic processes develop faster, as do the symptoms of the disease.
- Improper nutrition.
- Being in direct sunlight without goggles.
Pathology often develops in people with a burdened hereditary history (the presence of the disease in parents and grandmothers). In most cases, the disease is diagnosed in the female population.
Age-related macular degeneration: the pathophysiology of the process
Like all degenerative changes, this disease has a complex mechanism of development. In addition, the pathogenesis of dystrophic processes is still not fully understood. It is known that under the influence of adverse factors, the tissue of the macula is irreversibly damaged. Most often, the pathology begins to develop in people suffering from vascular diseases (atherosclerosis, diabetes), obesity. Also, the disease is almost always found among the smoking population. Due to blockage of the vascular bed and insufficient nutrition of eye tissues, age-related macular degeneration develops. The pathogenesis of the disease is based on a violation of the redox balance. The main role in this process is played by free radicals. These substances form in the macula for several reasons. Firstly, oxygen and light constantly influence the macula of the retina. In addition, in this area there is an accumulation of fatty acids, which tend to oxidize. Another factor in the pathogenesis of the development of pathology is the origin of the retina. After all, this shell of the eye is considered a peripheral analyzer and is directly connected to the brain. Therefore, it is especially sensitive to "oxygen starvation."
All of these factors predispose to the fact that the tissue of the macula is gradually thinning. As a result of exposure to radicals, cell membranes are destroyed. The retina becomes even more sensitive to light. Under the influence of ultraviolet and infrared radiation, AMD develops even faster. All these processes lead to the fact that the macula epithelium begins to “lose” pigment receptors and undergo atrophy. If the destruction of the macula is not stopped in time, tissue detachment occurs. The final stage is the appearance of scars and the development of blindness.
Forms of age-related retinal degeneration
There are 3 forms of macular degeneration. This classification is based on morphological changes that occur in retinal tissue. Such a division is necessary in order to determine the tactics of treating the disease.
Morphological types of disease:
- Age-related macular degeneration - wet form: characterized by the presence of exudate. This option is rare, in 20% of cases. It is characterized by a rapidly progressive course. If a person's vision is rapidly deteriorating (within a few days), then it is worth suspecting a disease such as age-related macular degeneration. The wet form develops due to neovascularization, that is, the appearance of a large number of new vessels on the retina. Given damage to cell membranes, their permeability increases. As a result, edema and hemorrhages develop.
- Age-related macular degeneration - dry form: characterized by a slow course. In another way, this type of pathology is called atrophy. Dry age-related macular degeneration develops in 90% of patients. On examination, drusen are noted - light foci of atrophy, pigment layer insufficiency, defects on the epithelium.
- Cicatricial form of macular degeneration. It is considered the final stage of AMD. It is characterized by detachment of the epithelium and the formation of connective tissue (scar). In this case, complete loss of vision is noted.
In some cases, the dry form of AMD turns into an exudative variant of the disease. Most often this occurs with vascular lesions, and in particular with diabetic retinopathy. Such changes indicate a worsening forecast and are a signal for urgent measures.
Symptoms of age-related macular degeneration
Depending on the form of AMD, the symptoms of the disease can develop both slowly and quickly. Often, for a long time, macular degeneration has not been felt for several years. With the dry form of AMD, druses appear on the surface of the retina - areas of atrophy. As a result, vision is gradually deteriorating. The pigment layer suffers to a greater extent, due to which the brightness of the colors is somewhat lost. Visual acuity may vary, but not significantly. The wet form of macular degeneration develops rapidly. In a few days, vision can significantly deteriorate, up to complete blindness. Due to edema and increased permeability of the membranes, hemorrhages can occur that are visible to the naked eye. Symptoms observed in AMD:
- Change the contrast and brightness of the image.
- Decreased visual acuity.
- Curvature, distortion of objects.
- Blurred image.
- The appearance of loss of visual fields.
- Inability to read despite wearing glasses.
With the gradual development of pathology, signs of the disease may be absent for a long time. Then a gradual deterioration of central vision occurs. Looking forward, most of the image becomes blurred. Nevertheless, peripheral (lateral) vision is maintained. Gradually, the affected area increases.
With a wet and scarred AMD, blindness occurs quickly. Unlike the dry type of degeneration, peripheral vision is rarely maintained. With timely treatment of AMD, the development of blindness can be stopped.
Diagnosis of age-related retinal degeneration
Age-related macular degeneration can be diagnosed in the early stages. Therefore, people suffering from vascular lesions need to be examined by an ophthalmologist 1-2 times a year. Diagnosis of AMD is based on anamnesis and a special examination. Older people often complain about the appearance of a “spot” in front of their eyes, resembling fog. The diagnosis of "macular degeneration" is most often made with visual impairment in women, especially if there is a history of type 2 diabetes mellitus, vascular atherosclerosis. In addition to the survey, a number of ophthalmological examinations are performed. Among them - the measurement of visual acuity, perimetry, stereoscopic biomicroscopy.
To assess the condition of the vessels, conduct fundus fluorescence angiography. Thanks to this study, it is possible to detect areas of epithelial detachment, atrophic drusen, neovascularization. However, such a method of instrumental diagnostics has contraindications and risks. Therefore, before deciding to have an examination, it is worth visiting an ophthalmologist and getting his consultation.
How to treat dry form of macular degeneration?
When confirming the diagnosis, it is necessary to immediately begin treatment of age-related macular degeneration. The dry form of the disease is less aggressive, so it gives in to drug therapy. This will not help get rid of the pathology in full, however, it will suspend (slow down) the process for several months or years. First of all, with AMD, you must follow a diet. Given that atrophic processes develop due to a lack of carotenoids and occlusion of the vessels of the fundus, the patient should exclude animal fats. To prevent atherosclerotic changes in the small arteries of the retina, you should eat a large number of fruits, herbs, vegetables. In addition, such a diet will help make up for the lack of vitamins and minerals.
To cope with free radicals, it is recommended to spend less time in the sun. Also, patients should use antioxidants. They include vitamin E and C. To improve the blood supply to the fundus, it is recommended to use antiplatelet agents, vasodilators.
Age-related macular degeneration - wet form: treatment of pathology
With the wet form of macular degeneration, not only drug therapy, but also surgical treatment is performed. Drugs that restore the pigment layer of the retina include Lutein and Zeaxanthin. These drugs belong to the group of antioxidants. In addition, it is recommended to eat foods containing zinc. If the disease has developed as a result of diabetic retinopathy, it is necessary to conduct a hypoglycemic therapy under the control of the glycemic profile.
Surgical treatment of retinal degeneration
Medication alone is not enough if the patient is diagnosed with age-related macular degeneration. Treatment of pathology should be combined with surgical correction. This is especially true for the wet form of AMD. Currently, laser treatment of macular degeneration is carried out in almost every ophthalmological clinic. It may be different. The choice of method depends on the stage of AMD and the manifestations of pathology. The following methods of surgical correction are distinguished:
- Laser coagulation of a neovascular membrane.
- Photodynamic therapy with Vizudin.
- Transpupillary laser thermal correction.
If possible and the absence of contraindications, transplantation of pigment epithelium, vitrectomy (with hemorrhage in the vitreous body of the eye) are performed.
Prevention of age-related retinal degeneration
Preventive measures include: following a diet, reducing body weight. For vascular lesions, smoking cessation is recommended. Also, direct sunlight should be avoided for people with light eye color. In addition, the use of vitamins to strengthen vision and trace elements refers to prevention.