Good Hope Eye Clinic

Type 2 CNV, formally termed 'Classic' age related macular degeneration (ARMD)

David Kinshuck

 

Wet ARMD (exudative/leaky)

Wet ARMD

retinal damage

VEGF
(vascular endothelial growth factor)

blood vessel growth

leakage..blood and fluid

give anti-VEGF drug

leakage stops for a while

In wet ARMD, new vessels grow under the central retina in the macular area, causing retinal leakage and swelling. (CNV..choroidal neovascularisation). The blood vessel frowth seems to be part of the eye's 'healiing' response to ack of oxggen/damage. The damaged retina releases a chemical VEGF (Vascular endothelial growth factor). The VEGF stimulates blood vessel growth, to produce the different types of wet ARMD. In addition, the new blood vessels leak, causing fluid under the retina in these condition.

The network of blood vessels usually progresses to cause a scar in the macular area. If the scar is small, sight is reasonable; but if large, the sight can be very poor. It is very difficult to predict whose dry ARMD will progress, but the risk factors include those mentioned above (soft drusen, high blood pressure, smoking, poor diet, lack of exercise). This is described below.

There are different types of wet ARMD

Type 2 CNV (formally termed 'classic CNV')

 

early cnv (macular degeneration)

New vessels growing under the central retina in a 'classic' pattern: Anti-VEGF treatment needed.  enlarge  Photo (case 12)

 

When blood vessels grow under the macula, this is termed choroidal neovascularisation (CNV). When the new vessels are seen easily on a fluorescein angiogram, they are called 'classic CNV': they look like a net of blood vessels.

When a doctor looks in the retina looks elevated, there may be tiny haemorrhages, a grey area, or exudates. Severe . In milder cases vision may still be good. The condition may develop over days or weeks, with increasing distortion or blurred central vision. If this process is early you can still read, but if it becomes severe reading with any magnifier is impossible. Treatment is based on anti-VEGF drugs,  although other treatment are available

This is usually a serious type of macular degeneration, serious because it can cause very poor central vision. It never blinds in the sense that you cannot see light and dark, but in its serious form it can damage the central vision so you can only see fingers or even the movements of hands. Once again, the side vision will normally be good, so you should always be able to walk around the house.

ARMD progression rate and relative risk of smoking geographic neovascular
active smoking x 3.4 x 2.5
passive smoking x 2

see