Exudative or wet AMD 22/03/2013
What is AMD?
Age-related macular degeneration, the gradual degeneration of the macula, is the primary cause of sight loss in the western world in patients aged over fifty. More than 25 million people currently suffer from this illness in the world, with an additional 500,000 every year, approximately. There are many subtypes of AMD but basically two broad forms: wet or exudative and dry or atrophic.
What are the effects of wet AMD?
The AMD is a degenerative eye disease that affects the area of the retina specialised in pinpointing details that helps us to read and make out people's faces (the macula). Exudative AMD, also known as wet or neovascular AMD, is the less common form of age-related macular degeneration (about 15 %) but tends to progress more rapidly. It requires immediate treatment to stop the central vision from being irreversibly destroyed within a short period of time (weeks or months).
Characteristics of wet AMD
This illness produces haemorrhages and leaks within layers of the retina, principally in the central zone: the macula. These haemorrhages, caused by small, abnormal veins (choroidal neovessels) that invade the retina from the layer below it (the choroids), end up destroying the neural architecture of the macula and lead to loss of vision right in the centre of the visual field.
Those suffering from AMD gradually lose central vision, making it difficult to carry out tasks that require precision, such as driving, reading or writing. Sufferers cannot recognise a person's face but they can walk without stumbling and remain relatively independent.
On the other hand, it may be difficult for them to estimate distances and heights, making going up or downstairs problematic.
This illness usually begins in one eye although it ends up affecting both. For this reason, patients may not realise they have a problem with their sight unless, by chance, they cover up the healthy eye and start to see distorted lines with the affected eye (metamorphopsia).
Can it be prevented?
As this illness is associated with age, AMD cannot be prevented. Greater incidence has been observed in smokers so that having a healthy diet, not smoking and undergoing regular eye tests as from fifty years of age should be the measures taken.
How is it treated?
The last few years have seen highly significant advances in the treatment of wet AMD which have revolutionised the treatment for this illness and have provided new hope of preserving the sight of our patients.
The main treatment to attempt to control wet AMD uses the application of angiogenesis inhibitors via intraocular injections direct into the vitreous cavity. These drugs block the molecule that causes the development and progression of neovascular membranes in wet AMD: the vascular endothelial growth factor (VEGF). This treatment manages to stop the illness in three out of four cases and improve it in one out of three. In specific or more resistant cases, other alternative treatments must be tried, such as laser photocoagulation, either directly or of the supply vessels, as well as photodynamic therapy and, in some cases, their combination with macular vitreoretinal keyhole surgery.
- Prior check-ups: a thorough ophthalmological examination is required, including a retina scan, autofluorescence, optical coherence tomography, fluorescein angiography and, in some cases, indocyanine green angiography.
- Intervention: carried out under local anaesthesia (drops) and is generally not uncomfortable. This is a short procedure carried out in an operating theatre or surgery but always under strictly sterile conditions.
- Precautions: before intervention, the eye and eyelids are thoroughly disinfected using iodine solutions.
- Risks: as with any procedure, the most serious risk is an eye infection but, if the eye is correctly disinfected before the operation, this risk is extremely low, less than one case in every thousand patients.
The Institut de la Màcula employs the Treatment Fusion© process developed by our centre to optimise and personalise treatment, reducing the risk of long-term loss of vision that can occur with other procedures currently in use.
The key to the success of this monthly treatment lies in the condition being treated even when the injury is inactive. In this way the treatment, and not the illness, takes the initiative. However, this could lead to over-treatment in some cases.
That's why the Fusion process is flexible, removing injections in the case of patients whose illness is more benevolent and also allowing, at the other extreme of the spectrum, monthly treatments when required. Compared with other strategies, treatment before the injury recurs reduces the risk of sight loss or the loss of the sight gained initially.
The Institut collaborates with the Barcelona Macula Foundation to improve current treatments for illnesses such as exudative AMD.
Dr. Jordi Monés, M.D., Ph.D.
COMB Medical license number: 22.838
Doctor of Medicine and Surgery
Specialist in Ophthalmology
Specialist in Retina, Macula and Vitreorretinal