pérdida de visión central por DMAE

Age-related macular degeneration or AMD is a disease that affects the central part of the retina, the macula, and, as its name indicates, it is a pathology that progresses as the patient’s age increases.

AMD causes central vision problems and can lead to blindness if it is not treated early.

Types of AMD

Currently, we classify AMD in two main forms:

  • Dry or atrophic AMD: the tissue in the area of the macula is atrophying and tightening. In some cases dry or atrophic AMD may progress to wet or exudative AMD.
  • Wet or exudative AMD: there is a thickening of the macular tissue, due to inflammation phenomena or the appearance of neovessels, i.e., abnormal vessels or small varicosities that grow under the retina in the area of the macula and lead to swelling, inflammation, presence of fluid and an increase in the thickness of this area. In advanced stages of wet AMD, areas of the macula with atrophied tissue may also appear.

There are also other types of AMD, the so-called “rare forms of AMD“, which are more atypical.

Causes

There are several factors that can influence the onset and progression of AMD, such as:

  • Lack of healthy habits: smoking, unhealthy diet, ultraviolent habits or lack of physical exercise.
  • Certain associated pathologies: high blood pressure, diabetes, high triglycerides or high cholesterol.
  • Genetic factors: most patients with AMD have a family history, i.e. people in their families who became blind when they grew up or lost their sight over the years and, therefore, some patients already know about the disease.

Symptoms

In the early stages, AMD can be asymptomatic and this makes detection difficult. As the patient’s age increases, the condition worsens and symptoms begin to appear.

Patients with AMD usually present symptoms that affect central vision, such as, for example

  • Difficulty in reading
  • Blurred central vision
  • Seeing objects of different sizes with each eye
  • Alteration of colors
  • Deformed straight lines

When a patient begins to notice vision loss, or even if he/she does not notice anything but is over 50 years old, he/she can perform a simple vision test at home to detect changes or improvement in central vision. This test consists of first covering one eye and then the other and looking at straight lines. If these lines appear deformed, it is a sign that a specialist must be consulted.

Diagnosis

To diagnose AMD, the following tests or studies can be performed:

  • Complete ophthalmologic examination with measurement of visual acuity near and far, Amsler test, campimetry or visual field (which analyzes the degree of impairment of central vision) and above all the examination of the fundus of the eye.
  • OCT (optical coherence tomography)
  • Color and autofluorescent retinography.
  • Contrast tests, such as fluorescein or green indocyanine angiography.
  • In specific cases, contrast vision, color vision, electrophysiology, microperimetry, etc. may be requested.

Treatment

At present, AMD cannot be cured, but existing treatments can slow down and delay its progression. The treatment to be followed may vary depending on the type of AMD:

  • Treatment for wet AMD: Wet AMD tends to be more aggressive and evolves more rapidly. The usual treatment for this type of AMD is usually by means of drugs that block the endothelial growth factor (anti-VEGF), which are administered through intravenous injections. This injection-based treatment must be followed periodically to stabilize the progression of this disease. In addition, it is important to carry out continuous check-ups in order to control the evolution and possible outbreaks of AMD.
  • Treatment for dry AMD: Nowadays, there is no curative treatment for dry AMD. Nutritional supplements are usually received in the early stages, as numerous studies have shown that they can slow the progression of the disease.

AMD is the leading cause of blindness in elderly patients in developed countries and, therefore, multiple research studies are being developed to detect early and cure this visual condition.

This may lead to more effective and efficient treatments in the near future.

Tips for preventing AMD

The main risk factor for this disease is age, as it mainly affects people over 50 years old. Against this factor there is nothing to do. However, research has been done on other associated factors that could help to slow down and stop the onset and progression of the disease.

It is therefore recommended to follow healthy lifestyle habits, such as:

  • Mediterranean diet
  • Smoking cessation
  • Complete annual analysis to control the appearance / evolution of associated diseases (diabetes, high cholesterol, etc.).
  • Control blood pressure
  • Periodic ophthalmologic check-ups
  • Physical exercise
  • Protection from ultraviolet rays

A healthy and balanced lifestyle will help us to avoid the risks of suffering this ocular pathology as we grow older.

Frequently asked questions

At what age does AMD appear? Can it appear in young people?

Age-related macular degeneration usually appears in people of advanced age, that is, from 50-60 years of age, and its incidence increases with the passage of time. Although this disease does not affect young people, there are forms of juvenile macular dystrophy of genetic origin that can manifest in a similar way, as well as other pathologies that can affect the macula, such as juvenile retinoschisis, Stargardt’s disease or Best’s vitelliform macular dystrophy.

How is AMD treated?

To date there is no treatment that can completely reverse the effects of AMD. However, in the case of wet or exudative AMD, there are treatments that can reduce the speed of vision loss, such as intravitreal injections and photodynamic therapy.

What do intravitreal injections consist of?

Treatment with intravitreal injections is effective in cases of exudative macular degeneration and consists of administering drugs into the eye. The most commonly used drugs in these cases are injections with Eylea®, Avastin® and Lucentis®. The procedure is preferably performed in the operating room to minimize the risk of infection, typical anesthesia is used and postoperative pain and discomfort are not usually experienced. This treatment is not applied in cases of dry or atrophic AMD.

Why are they injected into the eye?

Intravitreal injections are made into the vitreous cavity, located at the back of the eye. It is done this way because, if it is done orally or by vein, the effects of these drugs would not reach the inside of the ulcer with the adequate intensity. Moreover, in some cases, in order to reach the necessary levels, the doses that would have to be taken orally would be higher and could cause more adverse effects.

Is macular degeneration operable?

The most common treatment for AMD is medical and only in some exceptional cases, in which a favorable response to the usual procedure is not obtained, surgery can be considered.

What are the latest advances in the treatment of AMD?

AMD is characterized by the inability of the eye to produce new cells to replace the malignant tissue of the macula. For this reason, the latest advances in regenerative medicine have been based on replacing the destroyed retinal cells with stem cells, which are subsequently transformed into retinal pigment epithelium cells. These studies are still in the experimental phase, but are promising.

Can contact lenses improve vision in AMD?

Although it is an irreversible disease, special magnifying lenses allow patients to read at a standard speed while learning to ignore the blind spot caused by the disease. Nowadays, the possibility of using soft-light filtering ullers is also being studied. However, this last option has yet to demonstrate clear scientific evidence.

Can the use of screens and mobile devices cause macular degeneration?

Currently, there are no consistent studies that directly relate the use of electronic screens and mobile devices to the onset of AMD.

Can AMD be prevented through diet?

Nutrition, lifestyle and environment play an important role in eye health. A healthy diet seems to delay the onset of AMD by 25%, both in the atrophic and exsudative forms. It is also essential to consume unsaturated fatty acids, such as those provided by foods like avocado or spinach.

Can a patient with AMD have cataract surgery?

In many cases probably yes, but certain factors must be taken into account that must be evaluated by the specialist, such as which of the two pathologies is causing the patient’s loss of vision or if there are other possibilities before surgery, such as a change of prescription or magnifying lenses.

In the case of atrophic AMD there is currently no evidence that undergoing cataract surgery improves the status of this condition and in exudative AMD, which is much less frequent, studies on the subject have been carried out but have not been conclusive.

With regard to those people who have a high incidence risk of suffering AMD but who do not yet manifest this pathology, we can state that there is currently no evidence that undergoing cataract surgery increases the risk of developing it.

What does angiography consist of? And an optical coherence tomography?

Fluorescein angiography is an ophthalmological test from which the specialist can study the blood circulation of the eye in order to diagnose retinal diseases. The test lasts 10 minutes and images of the retina are obtained thanks to a contrast agent injected into a vein, usually in the arm.

The optical coherence tomography or OCT is a test in which, from a light source, we obtain the image of the section of the eye we want to study, whether sections of the retina, the optic nerve or the anterior segment of the eye, in the greatest possible detail. Currently, this technology also makes it possible to obtain images of retinal circulation without the need for contrast, the so-called optical coherence angiography.

Medical content revised by - Last revision 07/05/2024

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