WHAT IS IT AND HOW TO RECOGNISE IT
The most severe form of MACULAR DEGENERATION is called “wet or neovascular“; it’s less frequent than the dry form (about 10-15% of the cases). It’s also often an evolution of the dry form; progressing faster and more severe.
This form of macular degeneration is called wet or exudative because it’s characterized by the formation of abnormal subretinal neo-vessels, with a very fragile wall. These vessels grow towards the retina and they are extremely permeable. They can form subretinal fluid potentially causing macular edema and lead to the detachment of the retinal pigment epithelium.
Neovascular senile macular degeneration, characterized by choroidal neovascularization (CNV), is present in less than 20% of all age-related macular degeneration (AMD) cases, but is responsible for approximately 90% of all cases of severe vision impairment and loss related to AMD.
Chronic inflammation develops when the retinal tissue is unable to control its natural inflammatory responses. Release of enzymatic granules from immune cells (macrophages) can cause rupture of the Bruch membrane, a very thin tissue that is located between the choroid and the retina. The rupture of the Bruch membrane allows subretinal neovessels invasion into the retinal tissue.
Therefore In wet macular degeneration, it’s essential to contrast the underlying chronic inflammatory process.
Retinal specialists can make the diagnosis for wet AMD and guide treatments by performing different types of retinal examinations. During the visit, the ophthalmologist examines the central part of the retina (examination of the fundus) with an instrument called the indirect ophthalmoscope.
Another very easy exam to perform, and very useful to monitor advancement is the optical coherence tomography (OCT, a non-invasive examination that allows imaging the different layers of the retina) and the OCT angiography (Angio OCT).
The current focus of wet AMD treatment is mainly drug therapies aimed at inhibiting the angiogenesis process that underlies the wet form of macular degeneration. VEGF inhibitors are injected directly in the area to be treated to block VEGF signalling, which is the key mediator in the process of neovessel formation.