age related macular degeneration

Summary age-related macular degeneration (AMD)

Age-related macular degeneration (AMD) is one of the most blinding diseases in Western countries. Several factors can cause the appearance of the disease, such as age, heredity, diseases such as hypertension , high cholesterol levels or smoking. There is also non-age-related macular degeneration and this can affect both children and teenagers, but the subject will not be discussed here.
The disease mainly affects elderly people over 55 years of age, and this incidence increases over the years, reaching more than 30% of the elderly population over 75 years of age. There are two types of AMD: dry and wet. They differ in the formation or not of new vessels and in the treatment received. The main risk groups include elderly people, smokers, people with high cholesterol and vascular problems, including high blood pressure.

AMD has a slow onset and is not painful, so it can be diagnosed too late. Although the disease rarely causes total blindness, it causes vision problems and discomfort in patients’ daily lives, such as reading or recognizing faces. Diagnostic tests involve visual field and acuity tests, as well as imaging tests to check the health of the retina and vessels in the back of the eye.
As AMD is essentially age-related, it is advisable to systematically screen individuals over 50 years of age every 2-4 years. Above 65, the same test should be done annually. People with risk factors should consult periodically.

There are medications to treat AMD. The options currently available are for cases of exudative AMD, that is, with the formation of new vessels. Medications inhibit vessel formation and must be injected inside the eyeball. In addition, there are options for surgeries to prevent vessel growth, such as retinal photocoagulation or photodynamic therapy.

In addition to preventing the progression of the disease, it is important that measures are adopted to rehabilitate and reorganize the space of the patient who has a weakened split. The education of the patient and his family is important to improve the quality of life and adapt the patient to the new situation.

Definition

Age-related macular degeneration (AMD) is a disease that affects the eyes. Specifically, AMD affects a region close to the optic nerve. This area is called the macula, responsible for central vision and when it is affected, vision does not completely disappear, as peripheral vision still remains. However, central vision becomes blurred. In general, AMD mainly affects the elderly (people over 55 years old), which is why it is called age-related macular degeneration (AMD).
There are two types of disease: dry AMD and wet AMD, which can be unilateral or bilateral.

Dry AMD is an atrophy of retinal tissue, with disappearance of light receptors (photoreceptors) in the deeper layers of the tissue. This is why this type of disease is also called the non-neovascular or atrophic form. There is no treatment for dry AMD, however, the condition can be improved by using antioxidants. It affects one third of patients with AMD and its evolution is slow, taking several years.

Wet AMD, also called neovascular AMD, occurs when blood vessels appear in the retinal tissue. This is the most rapidly developing and most severe form of AMD, however it is treatable. These blood vessels are abnormal and responsible for retinal edema or hemorrhage in the macula. It is important to mention that dry AMD can progress to wet AMD.

According to the AREDS (Age-Related Eye Disease Study), there are different classifications of AMD:

– No AMD: few or no drusen (small white lesions on the macula).

– Early AMD: very small or medium drusen.

– Intermediate AMD: significantly large drusen, and in large numbers.

– Advanced AMD: neovascularization.

Epidemiology

Age-Related Macular Degeneration (AMD), as its name suggests, is a disease that appears in the elderly, typically in people over 55 years of age. According to data from studies, 10 million people in the US have the disease or are at considerable risk of developing it in the coming years. The risk of developing AMD increases with increasing age of the patient.
According to data from the Brazilian Council of Ophthalmology, 90% of AMD cases refer to the dry non-exudative form, and the rest of cases appear in the exudative form. A Brazilian study in centers in Pernambuco revealed that the frequency of AMD varies from 23 to 30% in ophthalmological centers in this state. It is estimated that in Brazil, almost 3 million people already have their eyesight compromised and their quality of life impaired by the disease. About 10% of the population between 65 and 74 years of age has the disease, and this number increases to 25% in people over 75 years of age.

Causes

The cause of AMD, whether dry or oozing, is age. In principle, dry AMD is more common than wet AMD (see Statistics ). There are other causes such as hereditary and environmental factors such as smoking, hypertension or obesity.

Age

Age is the main factor for wet or dry AMD. With age, the macula deteriorates and there is a loss of photoreceptors, and thus loss of vision, especially central vision. AMD begins to occur in people over 55 years of age, and the incidence and risk of developing the disease increases with increasing age. Thus, about 10% of people between 65 and 74 years old are affected, and this number can increase to 25% in Brazil in elderly people over 75 years old or up to 33% in other countries.

There are also cases of macular degeneration in children and adolescents, not included in the AMD classification (since they are not related to advanced age). The main causes of this type of disease are hereditary.

Heredity

Macular degeneration can be linked to genetic inheritance and can also occur in young individuals, not being a case of AMD (related to aging). However, a person with a family member with AMD has a higher risk of developing the disease after age 55.

smoking

Smoking is not only bad for the health of the smoker, but also for those around him. Smoking is a major risk factor for many diseases, including cardiovascular disease. But tobacco also harms other vessels in the body, such as the vessels in the retina (eye). Smoking can trigger the onset of AMD.

Hypertension

High blood pressure can weaken blood vessels. Thus, retinal vessels can also be affected and develop AMD.

Overweight

Excess weight is a risk factor for AMD. Any deposits such as cholesterol in the blood vessels can cause the condition.

We can say that dry AMD is a risk factor for the development of wet AMD.

AMD risk groups

The main risk groups of people who may develop age-related macular degeneration (AMD) are as follows:
– People over 55 years of age, with the incidence increasing with increasing age.
– People with a close family member with AMD
– Smokers
– People with hypertension
– People with hypercholesterolemia (high cholesterol) and dyslipidemia

– Obese people
– People with vascular disease
– Women
– Caucasians
– People with light eyes
– Sedentary lifestyle

The elderly

Age is the main risk factor for dry or exudative AMD, with the elderly being the most affected by the disease, which affects patients over 55 years of age. Thus, with the aging of the population, the number of cases of AMD progressively increases. In France, AMD affects 1 to 2% of people aged 50 to 60 years and 25% of people aged 70 to 80 years. Half of people over 80 suffer from AMD.

People with a family member with AMD

There is a hereditary factor to AMD, not to mention the macular degeneration that occurs in children and teenagers.

Obesity, hypertension, smoking, cardiovascular disease

These are diseases that inhibit the vascular system as well as the vasculature of the retina. Thus, these diseases can precipitate the onset of the disease.

Caucasian types

AMD is more common in Caucasians (Europe-North America). Then comes the Asian type. However, AMD is much less common in the African type.

Symptoms

Age-related macular degeneration (AMD) is characterized by central vision disorder, resulting in a spot in the center of the image transmitted to the brain. It is important to note that no pain is felt.

The appearance of a central point (called a scotoma) in the visual field shows that the disease has already evolved. Before the scotoma appears, the patient will complain of the following symptoms:
– Need for greater light intensity for reading or precision activities;
– Decreased visual acuity affecting one or both eyes;
– More difficult reading, because the vision becomes blurred;
– Perception of the vagueness of colors, becoming blurred and difficult to identify;
– Distortion of lines. This symptom appears only in the case of exudative;
– Distorted vision: problems recognizing shapes, due to scotoma or image distortion;
– Slower image recovery after a blinding light.
– Dark or whitish spot in the center of vision (scotoma).

Note that AMD is usually asymptomatic at early diagnosis, delaying patient treatment. Although there is no treatment for dry AMD, its diagnosis can delay the progression of the disease through the use of medication. Decreasing the progression, the patient’s visual acuity improves and also his quality of life.

Diagnosis

The diagnosis of age-related macular degeneration (AMD) can be made using several methods. First, the doctor will conduct an interview by collecting information about the patient’s visual acuity. The symptoms described may cause your doctor to suspect AMD and refer you to an ophthalmologist.
The ophthalmologist has at his disposal several tests for the diagnosis of AMD. The analyzes that can be carried out are:
– Checking the macula
– Assessing visual acuity

– Assessment of the visual field, with detection of a possible scotoma (spots in the visual field) or metamorphopsia (distortion of objects, straight lines).

One such supplement is the Amsler Screen exam. This screen is a design with parallel and perpendicular lines and looks like a sheet of squared paper. The patient must focus eyes on a point in the middle of the grid and thus perceive whether the vision is distorted or not.
The ophthalmologist can use complementary exams for the diagnosis of AMD by performing the following analysis:
– Retinal fluorescein angiography.
– Choroid angiography with indocyanine green.
– Tomography of the retina.

Note that, in principle, given the asymptomatic nature of AMD, the disease is often detected during a routine examination by an ophthalmologist. Routine checkups are recommended every 2-4 years for people over 50. Above the age of 65, screening should be done every year. It is recommended that people in risk groups carry out a periodic review.

Complications

The main complication of AMD is decreased visual acuity. Blindness is never complete, as only a portion of the retina is affected, namely the macula. The macula is responsible for central vision and thus, peripheral vision is not affected. AMD is the leading cause of blindness in Western countries.
In dry AMD, macular degeneration is slow and the symptoms appear late, also delaying the patient’s treatment. The absence of pain in AMD also delays the diagnosis. Dry AMD is unfortunately not treatable. However, when AMD is diagnosed early, it is possible to slow down the progression of the disease, taking antioxidants, for example. If left untreated, this form of the disease can progress to wet AMD and thus rapidly decrease the patient’s visual acuity.

In wet AMD, visual acuity deteriorates much faster and can lead to partial blindness within a few weeks.

AMD is a disabling disease even if vision loss is never complete. Furthermore, AMD may exist in only one eye, with the other eye unaffected for many years.

Treatments

Recommended treatment for age-related macular degeneration (AMD) depends on the type of disease (dry or weeping), unilateral or bilateral (one or both eyes). In each type of AMD, the doctor will always discuss the patient’s rehabilitation such as reorganizing their space, avoiding risk factors and complications. This is important, as AMD causes the patient to become unable to rely solely on their vision.
– In the case of early AMD, there is no cure, but the treatment will educate the patient to better understand the disease and its exacerbation (sudden and rapid reduction in visual acuity, appearance of scotoma = point in a central place in the field of vision, metamorphopsia = deformation and straight lines). Recognizing the symptoms of the worsening of the disease, the patient consults and receives the treatment faster.

– Intermediate cases of AMD: prescription of antioxidants and zinc .

– In case of advanced but unilateral AMD: take antioxidants and zinc.

– In case of advanced AMD, bilateral: treatment of risk factors (smoking, obesity) that help with rehabilitation.
– In case of dry AMD (without new vessels): there is no drug treatment, but palliative measures help visual rehabilitation.
– In cases of exudative AMD (with the presence of new vessels): drug therapy or photodynamic therapy or laser photocoagulation, help in visual rehabilitation.
The drugs used in cases of AMD are:

– Antioxidants : vitamin C (500 mg), vitamin E (400 IU), carotenoids (beta-carotene 15 mg) in high doses. Zinc (usually 80 mg) is also recommended. Zinc is an antioxidant coenzyme.
Note on antioxidants. A prospective double-blind study conducted by the National Eye Institute and Bausch + Lomb published in 2001 in JAMA Ophthalmolgy (DOI: 10.1001/archopht.119.10.1417), called AREDS, in which 3640 patients, aged 55 to 80 years, in different stages of AMD, were randomly administered one of the following 4 treatments: antioxidants (500 mg of vitamin C, 400 IU of vitamin E and 15 mg of beta-carotene), 80 mg of zinc, antioxidants plus zinc, or a placebo. Among the results, the researchers noted that after 5 years of treatment the risks of progressing to an advanced form of AMD were 28% with a placebo, 23% with antioxidants alone, 22% with zinc alone, and 20% with antioxidants plus zinc. Only the combination of antioxidants and zinc was found to be statistically significant.1 .
Risk with beta-carotene
The (AREDS) study, as well as the AREDS2 study, showed that long-term use (4 to 8 years) of beta-carotene (20 mg or more) led to an increased incidence of lung cancer and death in male smokers. These effects began as early as 18 months after starting treatment with beta-carotene.

– Ranibizmab: drug used as an injection. Inhibits the formation of new vessels. Ranibizmab is an antineovascular drug, it is a VEGF (Vascular Endothelial Growth Factor) inhibitor. It is indicated in the wet form of AMD. This drug is injected into the eye intravitreally. Other VEGF inhibitors are aflibercept or pegaptabnib.

– Photocoagulation of the retina: thermal laser treatment to block the new vessels.

– Photodynamic therapy: Infrared laser treatment with intravenous injection of Verteporfin®. The application reduces the formation of new vessels.

– Visual aids: Visual aids can improve visual acuity. An example is the use of a magnifying glass and special glasses.

– A French study published in February 2013 showed that the intake of omega-3 (especially docosahexaenoic acid or DHA) reduces the risk of developing wet AMD by 68%. This component can be found in fatty fish, canola oil, walnuts and flaxseeds.

Surgery
In some severe or advanced cases, especially with AMD in both eyes, surgery may be necessary.

Tips

– If age-related macular degeneration (AMD) appears, it is necessary to take prescribed medication to slow the progression of the disease, even if AMD does not cause total blindness.
– People suffering from AMD, as well as hypercholesterolemia , hypertension or smoking, should not only take medication regularly, but also stop smoking.
– In AMD, it is advisable to rearrange the environment to avoid falls or injuries due to poor visual acuity. Especially stairs, rugs, tables and other objects are thought of.
– Those who have become visually impaired due to AMD should not hesitate to seek help from organizations for advice, encouragement and support. Ask your doctor and your ophthalmologist about these organizations and patient groups. It is important not to isolate and confine yourself due to illness. Understanding the disease is also a way to better accept it.

Prevention

– To avoid the appearance of age-related macular degeneration (AMD), avoid risk factors such as:
>  Smoking  (active or passive)
>  High blood pressure
>  High cholesterol
Thus, a smoker not only puts his own health at risk, but also the of your relatives. To avoid hypertension and hypercholesterolemia pay attention to your diet. Regular physical activity and constant water intake (at least 2 liters a day) helps fight the disease. Current recommendations on physical activity are to perform everyday activities such as housework, gardening, walking, etc. for at least 30 minutes. It is also advisable to practice cardiovascular activity twice a week for at least 1h30min.

A person who already suffers from high blood pressure or high cholesterol must take medication carefully to avoid a worsening of the disease and complications such as AMD.
– Foods containing antioxidants are recommended to prevent AMD, such as vitamin C , vitamin E and zinc . It is also recommended to consume fruits such as strawberries, raspberries, cherries, as they are rich in antioxidants.

– It is advisable to see an ophthalmologist regularly to be screened for AMD, especially for people at risk. This is particularly important if there is a family history of the condition. For the elderly (over 55 years), it is advisable to practice screening every 2-4 years. For people over 65, it is still advisable to see an ophthalmologist every year.

– Knowledge of the symptoms of AMD is important for the diagnosis of the patient and for him to receive adequate treatment

– As you can see in the AMD treatment section , a French study published in February 2013 showed that the intake of omega-3s (especially docosahexaenoic acid or DHA) reduces the risk of developing wet AMD by 68%. DHA can be found in fatty fish, canola oil, walnuts and flaxseeds.

– A Harvard study found that regular consumption of spinach, rich in lutein and zeaxanthin, reduces the risk of suffering from AMD.

Jeanne Kenney
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I’m a stylist trainer, a content creator, and an entrepreneur passion. Virgo sign and Pisces ascendant, I move easily between my dreams, the crazy world I want, and my feet on the ground to carry out my projects.

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