Macular degeneration: types, symptoms and treatment

Central vision, which depends on an ocular structure called the macula, is what allows us to focus on the details and perform daily activities such as reading a book, driving or even recognizing the face of a person. This type of vision is the one that is affected when a disorder known as degeneration occurs. macular, a disease that affects older people more and ends up causing a loss of vision.

In this article we explain what macular degeneration is, what are its two most common forms and the symptoms associated with each of them. In addition, we will tell you what are the main risk factors that lead to the appearance and development of this eye disease, as well as the treatments currently available.

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What is macular degeneration?

Macular degeneration, also called age-related macular degeneration, is an inherited neurodegenerative eye disorder that gradually affects central vision, which is dependent on the macula and the one that provides us with the necessary visual acuity to carry out tasks such as driving, reading or recognizing a person's face.

The macula is a tiny part of the eye, in the form of a yellowish spot (due to the high concentration of two pigments that give it that color), which is located in the central area of ​​the retina. It is made up of the fovea, located inside the macula and responsible for color perception; and the foveola, located within the fovea, is what allows us to have maximum visual acuity.

In macular degeneration, as its own name indicates, there is a progressive deterioration of the macula, which is what allows us to perceive details and movement, which is why people who suffer from this condition end up suffering a significant loss of vision, especially related to fine details, either near or far.

This loss of central vision entails a series of negative consequences in the daily life of people who suffer from this condition, whose age is usually advanced. Macular degeneration is considered one of the main causes of blindness and low vision, and at the moment there is no known cure.

Currently, this disease affects 1.5% of the population, and if only people over 50 years of age are considered, the prevalence increases to 5.3%. Next, we are going to see what the two main forms of macular degeneration consist of.

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Types and their symptoms

There are two types of macular degeneration: dry, which is the more common of the two; and the humid one, less frequent but more serious. Let's see in more detail what each of them consists of.

Dry or atrophic macular degeneration

Dry macular degeneration is the most common type, accounting for 85% of all cases. Photoreceptors in the macula (light-sensitive cells) and the retinal pigment epithelium are impaired progressively, and deposits or extracellular waste products called drusen are formed.

The presence of drusen in the retina is relatively normal after the age of 45, and very frequent in people over 65 years of age; however, an increase in the number and size of them is often the first sign of possible macular degeneration. The result is blurry or speckled vision, and loss of central vision.

Dry macular degeneration evolves slowly over time and is developed in three stages:

early stage

Presence of small and medium-sized drusen, without loss of vision or symptoms.

middle stage

The person presents medium and large drusen, and vision may appear with spots in the center of the visual field. Sometimes the subject may need more light for tasks that require attention to detail.

advanced stage

Presence of multiple drusen deposits, destruction of the retinal pigment epithelium and the photoreceptor cells of the macula. At this stage, blurred vision occurs and, over time, loss of vision.

Wet or exudative macular degeneration

Wet or exudative macular degeneration is the least frequent form (around 15% of cases) but the most serious. It happens when blood vessels (which make up the neovascular membrane) begin to grow abnormally behind the macula, causing it to leak fluid and blood. These exudations end up causing scars and, consequently, macular damage.

In this form of macular degeneration, central vision loss occurs rapidly. Its development does not occur in stages, as occurs with the dry form, and the damage is more severe. The most common initial symptom is to see deformed straight linesyes, as if they had a wavy silhouette. Vision can become blurred or completely lost in a very short period of time (days or weeks).

There are two subtypes of wet macular degeneration: the occult, which occurs due to fluid spills and the growth of new blood vessels under the retina, and causes a milder vision loss; and the classic one, whose severity is greater in terms of loss of vision and occurs because the growth of blood vessels and scarring generates large debris, responsible for the lesion in the macula

Risk factor's

The main risk factor for macular degeneration is age, since for people over 50 the probability of suffering from this disease increases considerably. Other relevant factors that may increase the risk of developing this disorder are the following:

1. Family and genetic history

Macular degeneration is hereditary and several genes have been identified that could be involved in the development of the disorder, so the risk increases if you have a close relative who suffers from the disease.

2. Obesity

According to research, people suffering from obesity are at increased risk of progressing from the early and middle stage to the advanced stage of the. disease.

3. smoking

Regular exposure to cigarette smoke increases the risk of developing the disease, and smokers respond worse to treatment.

4. Race

Caucasians are at higher risk for muscle wasting compared to other races, such as African-Americans.

5. Cardiovascular diseases and hypertension

There is a relationship between diseases that affect the heart or hypertension and macular degeneration.

6. Sex

Women are more prone to macular degeneration That men.

Treatment

Currently, there is no treatment that can prevent vision loss caused by dry macular degeneration when it reaches its most advanced stage. However, yes it is possible to slow or prevent the disease from progressing from the early phase to more advanced stages through the use of high doses of antioxidants and minerals such as zinc, according to the indications of the National Institute of Ophthalmology.

To treat wet macular degeneration there are several therapeutic alternatives: laser surgery, used to destroy the blood vessels that cause macular damage; photodynamic therapy, which involves injecting a substance into the body and then activating it using a light that illuminates the blood vessels in the eye; and injections into the eye with anti-VEGF drugs, which kill growth factors that promote the development of abnormal blood vessels.

However, macular degeneration and the vision loss associated with this disease can continue to progress, even while receiving treatment. For now, there is no known fully effective cure or treatment, but research continues in this regard.

Bibliographic references:

• Chávez Pardo, I., González Varona, D., & de Miranda Remedios, D. YO. (2008). Age-related macular degeneration. Camagüey Medical Archive Magazine, 12(2), 0-0.
• Curcio, C. A., Medeiros, N. E., & Millican, C. L. (1996). Photoreceptor loss in age-related macular degeneration. Investigative ophthalmology & visual science, 37(7), 1236-1249.
• Flores-Moreno, S., & Bautista-Paloma, J. (2008). Treatment of age-related macular degeneration: a pending issue. Archives of the Spanish Society of Ophthalmology, 83(7), 405-406.