Age-related macular degeneration (AMD) is a degenerative disease of the macula that causes a progressive decrease in central vision. The macula is a small area located in the centre of the retina, the back layer of the eye that transforms light and images entering the eye into nerve signals that are sent to the brain.
The macula is responsible for us seeing small details clearly, making vision clearer both near and far. AMD affects only central vision, peripheral vision is not altered.
It affects most of the people over 65 years of age.
Furthermore, as it is closely related to ageing, it is estimated that the number of people with macular degeneration could double in the next 20 years, due to the increase in life expectancy of the population.
Types of AMD
We classify AMD into 2 variants, with different evolution and prognosis:
Dry or atrophic macular degeneration
It constitutes 85% of all AMD cases. The dry form presents a slow evolution over time (years).
Wet or exudative macular degeneration
The least common but most serious. Severe and rapid visual loss (days or weeks) is a result of the formation of anomalous blood vessels, which form a vascular meshwork below the macula and which we know as neovascular membranes.
When to go to the ophthalmologist?
In milder cases and when only one eye is affected, patients may have no symptoms. However, when the disease progresses the patient may suffer some of these symptoms :
- Blurry vision
- Undulation of straight lines
- Distorted objects
- Presence of a central spot
All of this will lead to difficulty performing daily life tasks such as reading, writing, driving, cooking, etc. If you have any alarming symptoms, it is advisable to go to the ophthalmologist to be evaluated and eventually treated in the shortest possible time, limiting as much as possible the irreversible visual consequences caused by AMD.
Being a disease inherent to ageing, there is no prevention, although early diagnosis and treatment will imply a better visual prognosis.
It is advisable by God Service Eye Clinic to undergo periodic eye checkups starting at age 50, especially in people with a history, and if there is any change in vision, go to the ophthalmologist without delay.
AMD treatment
Before starting any treatment, it is necessary to perform a complete ophthalmological examination. Sometimes we perform fluorescein angiography (injection of an intravenous contrast that allows the location and size of the neovascular membranes to be studied in greater detail) to confirm the diagnosis and an optical coherence tomography (scanner at the level of the macula, which shows indirect signs of disease activity) to help us during follow-up.
Wet or exudative AMD should be treated with intravitreal injections of antiangiogenic drugs (ranibizumab, aflibercept or in selected cases, bevacizumab). With this, we manage to slow down or even stop the progression of the disease in a large number of patients.
Currently, 70% of treated patients manage not to lose vision after a year of treatment and 40% manage to end up with vision above 0.5, which implies the possibility of being able to drive.
Intravitreal injections must be administered, for greater safety and comfort of the patient, in operating rooms or clean rooms, and therefore under strict sterile conditions.
Its administration is practically painless, thanks to the instillation of anaesthetic drops, and it is well tolerated by patients. Does not require preoperative. The postoperative period only requires applying antibiotic eye drops to prevent infection. The risk of complications if we follow these guidelines is extraordinarily low.
Atrophic AMD does not yet have a curative treatment. The daily intake of antioxidant complexes and a healthy diet (rich in antioxidants and Omega 3), as well as avoiding tobacco and limiting exposure to sunlight, seem to slow down the progression of the disease.
Intravitreal injections
It is a simple surgical procedure that aims to inject drugs directly into the eyeball (vitreous cavity).
This allows very high concentrations of medication to be achieved intraocularly that would not be achieved by another route (oral or intravenous) since the eye is an organ isolated from the rest of the body and this makes it difficult for drugs that are not administered intravitreally. reach sufficient concentrations inside.
Photodynamic therapy
Photodynamic therapy is a treatment that consists of the intravenous injection of an active ingredient called verteporfin which is subsequently activated for 83 seconds with a non-thermal laser.
During the session, a contact lens is placed to be able to place the spot in the area we want to treat in the same way as we do in conventional laser treatment. Anesthesia drops are placed so that the patient does not suffer discomfort in the cornea.
The duration of laser exposure can be reduced by half if necessary. The treatment is outpatient and the patient is recommended not to be exposed to direct light for two days since, being a photosensitive substance, it can cause skin wounds.
The objective of photodynamic therapy is to stimulate platelet aggregation and cause obliteration of the vascular structure to be treated.
