Related macular degeneration
The age-related macular degeneration (AMD or ARMD, in English) is a multifactorial disease that affects the central area of the retina, called the macula. It is slowly progressive and can lead to complete and irreversible loss of central vision.
In industrialized countries, is the leading cause of low vision in people over 50 years of age.
It usually affects from 60 years and its frequency in the population increases with increasing age. It is almost always bilateral.
The causes of the disease appear to be genetic and environment-related. Smoking is considered a risk factor for severe, dose-dependent, while less clear and inconsistent correlations with exposure to sunlight, high blood pressure, obesity, cataract surgery. The most important causal factors, however, can not be modified, first of all genetic predisposition, age, and, finally, skin type have a "clear".
Types and Symptoms
The disease presents as a decrease of the view in the central area of the visual field and / or with a deformation of the images that constitute the most important premonitory symptom. Characteristic sign of the disease are the drusen, yellowish spots of the retina that detects the ophthalmologist during the examination of the fundus, especially if large (greater than 125 microns).
We recognize two types of macular degeneration:
"dry" or non-exudative;
"wet" or exudative or neovascular.
In dry AMD vision loss is usually gradual and depends on the extent of the lesions (drusen) in macular level. There is no proven treatment for this form; However, not all patients experience a severe reduction of visual capacity.
Comprises about 90% of the cases of persons subject to this pathology.
The peculiar characteristics:
Absence of macular edema
Hard drusen; Area macular form protein deposits and blood glucose due to resorption. The edges are defined.
There are no subretinal hemorrhage
Comprises approximately 10% of cases pathological.
The peculiar characteristics:
Significant presence of macular edema
Soft drusen; deposits have greater spatial diffusion, with indistinct borders. The proliferation of blood vessels, due to hypoxia, tends to aggravate the clinical picture.
Frequent presence of retinal hemorrhages beneath.
In exudative AMD (form "neovascular") the view is threatened by the membrane formation of new blood vessels beneath the retina, in departure from the choroid, the layer between vascularized retina and the sclera, in correspondence of the macula. The neovascular membranes often tend to bleed and / or exude fluid that collects under the retina. If left to their fate neovascular membranes tend to form a large scar in the center of the retina, resulting in a decrease in central vision. The new blood vessels tend to "lift" the retina, making ineffective the perception and transmission of visual signal.
An eye examination is not always sufficient for a correct diagnosis.
There are some instrumental tests that the eye doctor should prescribe to confirm the diagnosis and classify the disease. The findings are as follows: optical coherence tomography, fluorescein angiography (fluorescein angiography) and, possibly, also with indocyanine green.
To date, therapeutic options are varied, although the results are still modest. Photodynamic therapy, intravitreal injections of triamcinolone or anti-angiogenic drugs (usually Lucentis, Macugen and Avastin) are the treatments available today, which can be administered either as monotherapy or in combination.
A major study derived from the study: Women's Antioxidant and Folic Acid Cardiovascular Study, published in February 2009, examined a sample of 5441 women; with this research demonstrates unequivocally that a nutritional supplement with folic acid (2.5 mg / d), pyridoxine (50 mg / d) and cianocobolamina (1 mg / d) compared to placebo, decreases the risk of developing age-related macular degeneration (AMD) by 34%. This finding is also confirmed from older studies.