Maintaining good vision to 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 over time begin to “wear out.” One of the first to suffer is eye tissue. It is believed that vision deteriorates from 40-45 years. This happens even in cases where a person has not previously had problems with vision throughout life. Visual impairment occurs gradually. Most people are worried about “farsightedness”, that is, the inability to see objects that are close. Sometimes, more serious problems develop. These include pathologies such as cataracts, glaucoma, etc. Another common disease is age-related macular degeneration. Such a disease is dangerous because 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. This area is directly connected to the brain (it is a peripheral analyzer). With the help of the retina is formed the perception of information and its transformation into visual images. 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 light is focused. Thanks to this function, the person’s vision is distinct and clear. Age-related macular degeneration of the retina leads to dystrophy of the yellow spot tissue. Not only the pigment layer is affected, but also the vessels that feed this area. Although 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 the elderly and old 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 widespread in America, Asia and Europe. Unfortunately, the disease is often diagnosed in the later stages. In these cases, one has 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 slow and progressive course. The causes of dystrophic changes in the yellow spot of the retina may vary. The main of them is the involution of eye tissue. However, in some people dystrophic changes occur more quickly, while others – more slowly. Therefore, there is an opinion that age-related macular degeneration is inherited (genetically), and also prevails in individuals of European nationality. Other risk factors include: smoking, hypertension, frequent sun exposure. Based on this, one can identify the causes of macular degeneration. These include:
- Vascular lesions. Atherosclerosis of small arteries is considered a risk factor. Impaired oxygen delivery to the tissues of the eye is one of the main mechanisms for the development of degeneration.
- Lack of vitamins and some trace elements. Among the substances necessary for the maintenance of retinal tissues are lutein and zeaxanthin.
- The presence of a large number of “free radicals”. They increase the risk of organ degeneration several times.
- Ethnic features. The disease is more common in people with bright eye color. The fact is that among the representatives of the Caucasians, 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 disease in parents, 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 developmental mechanism. In addition, the pathogenesis of dystrophic processes is still not fully understood. It is known that under the influence of adverse factors, the macula tissue is subjected to irreversible damage. 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 the disturbance of the redox balance. The main role in this process is played by free radicals. These substances are formed in the macula for several reasons. First, the yellow spot of the retina is constantly affected by oxygen and light. In addition, in this area there is an accumulation of fatty acids, which tend to oxidize. Another factor pathogenesis 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 particularly sensitive to “oxygen starvation.”
All of these factors predispose to the fact that the macula tissue is gradually thinning. As a result of exposure to radicals, cell membranes are destroyed. The retina is 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 epithelium of the macula begins to “lose” pigment receptors, undergoes atrophy. If time does not stop the destruction of the macula, 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 the morphological changes occurring in the retinal tissue. Such a division is necessary to determine the tactics of treatment of the disease.
Morphological types of the disease:
- Age-related macular degeneration – the wet form: characterized by the presence of exudate. This option is rare, in 20% of cases. It is distinguished by a rapidly progressive course. If a person’s eyesight 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 the damage to the cell membranes, their permeability increases. As a result, edema and hemorrhage develops.
- 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 – bright foci of atrophy, insufficiency of the pigment layer, defects on the epithelium.
- Cicatricial form of macular degeneration. It is considered the final stage of AMD. Characterized by detachment of the epithelium and the formation of connective tissue (scar). At the same time there is a complete loss of vision.
In some cases, the dry form of AMD turns into an exudative version of the disease. Most often this occurs in vascular lesions, and in particular – diabetic retinopathy. Such changes indicate a deterioration in the forecast and are a signal for the provision of urgent measures.
Symptoms for 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 does not make itself felt for several years. With the dry form of AMD on the surface of the retina appear drusen – areas of atrophy. As a consequence, the vision gradually deteriorates. The pigment layer suffers to a greater extent, due to which the brightness of the colors is somewhat lost. Visual acuity may vary with this, but only slightly. The wet form of macular degeneration develops rapidly. In a few days, vision can deteriorate significantly, even to complete blindness. Due to edema and an increase in membrane permeability, hemorrhages can occur, which 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, the symptoms of the disease may be absent for a long time. Then there is a gradual deterioration in central vision. When looking ahead, most of the image becomes clouded. However, peripheral (lateral) vision is maintained. Gradually, the affected area increases.
With a moist and cicatricial form of AMD, blindness occurs quickly. Unlike dry-type degeneration, peripheral vision is rarely maintained. With the timely treatment of AMD, development of blindness can be stopped.
Diagnosis of age-related retinal degeneration
Age-related macular degeneration can be diagnosed early. Therefore, people suffering from vascular lesions should be examined by an ophthalmologist 1-2 times a year. Diagnosis of AMD is based on anamnesis and special examination data. Older people often complain about the appearance of “spots” in front of his eyes, resembling fog. Diagnosis "macular degeneration" most often put in case of deterioration of vision in women, especially if there is a history of diabetes mellitus type 2, vascular atherosclerosis. In addition to the survey, perform a number of ophthalmologic examinations. Among them – measurement of visual acuity, perimetry, stereoscopic biomicroscopy.
To assess the state of the vessels, fluorescein angiography of the fundus is performed. Thanks to this study, it is possible to detect areas of detachment of the epithelium, atrophic drusen, neovascularization. However, this method of instrumental diagnostics has contraindications and risks. Therefore, before you decide on a survey, you should visit an ophthalmologist and get his advice.
How to treat a dry form of macular degeneration?
Upon confirmation of the diagnosis, it is necessary to immediately begin treatment for age-related macular degeneration. The dry form of the disease is less aggressive, so it can be treated with medication. This will not help to get rid of the pathology in full, however, it will stop (slow down) the process for several months or years. In the first place, it is necessary to follow a diet with AMD. Considering the fact that atrophic processes develop due to the lack of carotenoids and ocular occlusion, the patient should exclude animal fats. To prevent atherosclerotic changes in the small arteries of the retina, a large amount of fruits, herbs, and vegetables should be eaten. In addition, such a diet will help fill 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. These include vitamin E and C. To improve the blood supply to the fundus of the eye, it is recommended to use antiplatelet agents, vasodilators.
Age-related macular degeneration – the wet form: the treatment of pathology
In the case of a wet form of macular degeneration, not only medical therapy is carried out, but also surgical treatment. Medications “Lutein” and “Zeaxanthin” are drugs that restore the pigment layer of the retina. These drugs belong to the group of antioxidants. In addition, it is recommended to eat foods containing zinc. If the disease has developed due to diabetic retinopathy, it is necessary to carry out glucose-lowering therapy under the control of the glycemic profile.
Surgical treatment of retinal degeneration
Drug therapy alone is not enough if the patient is diagnosed "age-related macular degeneration". Pathology treatment should be combined with surgical correction. This is especially true of the wet form of AMD. Currently, laser treatment of macular degeneration is carried out in almost every ophthalmologic clinic. It may be different. The choice of method depends on the stage of AMD and the manifestations of pathology. There are the following methods of surgical correction:
- Laser coagulation of the neovascular membrane.
- Photodynamic therapy with Vizudin.
- Transpupillary laser thermocorrection.
If possible, and no contraindications, transplantation of the pigment epithelium, vitrectomy (with hemorrhage into the vitreous body of the eye) are performed.
Prevention of age-related retinal degeneration
To preventive measures include: diet, weight loss. With vascular lesions, smoking cessation is recommended. You should also avoid direct exposure to sunlight by people who have a bright eye color. In addition, the prevention of the use of vitamins to strengthen eyesight and trace elements.