Retina and macular degeneration (AMD genetic testing)

Age-related macular degeneration is part of the group of diseases called degenerative maculopathies (macular degenerations). Specifically, the age-related form is the most frequent, especially in women, and appears from the sixth decade of the person’s life onwards. It appears bilaterally, although not always with the same severity. It affects the macula, which is the central part of the eye where distinct, high-resolution vision has its seat.
The pathological picture is rather complicated, comprising several alterations (drusen formation, retinal neovascularization, detachment of the pigment epithelium), which can occur either individually or simultaneously and, if not detected in time and treated, lead to blindness.
Tests that are carried out to detect the evolutionary stage of degeneration and classify the type of damage are fluorescein angiography and OCT; the former consists in injecting intravenously a contrast medium and observe, through a fundus camera, the passage of the contrast medium through the vessels and retinal layers and the related alterations.
The most proven therapy worldwide consists of intravitreal injections of anti-VegF drugs (such as Avastin, Lucentis, Macugen, etc.), all these being substances that act against neovascularization and therefore against the main complications of macular degeneration in its “wet” form.

Insights

Age-related macular degeneration is characterized by the appearance of different alterations, which may occur either individually or simultaneously.

The first event is the formation of drusen: it is an accumulation of detritus, resulting from the metabolism of photoreceptors, which in normal conditions are eliminated through the choriocapillaris circulation. In old age, however, it is quite frequent that a process of atrophy of the retinal pigment epithelium and thickening of Bruch’s membrane arises, preventing such elimination. Therefore, the detritus accumulates in the area of Bruch’s membrane and over time tend to calcify. Another manifestation of age-related macular degeneration is the detachment of the pigment epithelium from the underlying Bruch’s membrane, caused by a deposit of serum from the choriocapillaris.

The proliferation of fibrovascular tissue that determines the neovascularization would also seem to originate from the choriocapillaris; to date, however, the precise cause of the formation of new vessels has still been under discussion.

It often happens that the new vessels rupture, causing haemorrhages that, along with the deposits of serum and detritus in the area of the pigment epithelium, lead to the degeneration of photoreceptors and to a significant visual loss. The treatment of age-related macular degeneration is aimed at stopping the neovascularization, stabilizing the disease and, in 70% of cases, improving visual acuity.

The drugs that are used in our department are anti-VegF, which are administered by intravitreal injection.
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