Wet AMD - Choroidal Neovascularization
Choroidal neovascularization occurs whennew blood vessels grow in the choroid layer of the retina, through the Bruch membrane and into the subretinal space (the space between the retina and the choroid) - crowding out proper functioning and sometimes resulting in blindness. The advanced or wet form of macular degeneration is an example of choroidal neovascularization.
Parts of the Retina
The retina consists of four different layers, specifically;
- outer neural layer which contains nerve cells and blood vessels;
- photoreceptor layer which is a single layer containing the light sensing rods and cones;
- pigmented retinal epithelium (RPE), with the bruch's membrane separating the RPE from the
- choroid layer, consisting of connective tissue and very fine capillaries known as choriocapillaries. They are responsible for carrying nutrients and oxygen to the the cellular layers above them.
The choroid layer contains most of the eyeball's blood vessels. It is also the layer prone to bacterial and secondary infections. There is no current effective medical treatment and so the abnormal blood vessel growth can readily develop as sight impairment or total vision loss.
In the case of wet AMD patients, the fluid and blood along with the formation of new blood vessels form scar tissues which are trying to repair damages but are ultimately the cause of vision loss and possibly blindness.
Symptoms may include: seeing flickering or blinking lights in the affected eye or eyes, blurred vision, loss of vision. Symptoms may occur fairly suddenly, (a few weeks). They can also inlcude variations in color perception, and wavy lines (noticeable in the amsler grid test).
The actual cause of choroidal neovascularization can vary.
- Macular Degeneration - the Wisconsin Beaver Dam Study funded by NIH showed that 1.2% of adults aged 43-86 with ARMD developed choroidal neovascularization.
- Myopia - the Beaver Dam study also demonstrated that choroidal neovascularization was caused by myopia in 5-10% of myopes.
- Ocular trauma is another likely cause of CNV. More than 50 vision conditions have been tied to the choroidal neovascularization formations. The known causes are related to degeneration, infections, choroidal tumors and/or trauma.
- Patients who wear soft contact lens who develop CNV may have experienced lack of oxygen to the eyeball due to a too-close fitting lens.
While there is no "cure" for CNV specific anti-angiogenic drugs like thalidomide, metalloproteinase inhibitors and angiostatic steroids are being tested inhibit the growth of extra blood vessels.
Testing using surgery has determined that partial removal of CNV is useless. So the focus has instead been on the FDA approved photodynamic therapy.
Photodynamic therapy attempts to stop the intrusion of fluid and inhibit further growth of the blood vessels. Photodynamic consists of two phases: First a special dye that attaches only to anomalous blood vessels is added by injection. Then a non-damaging laser activates a compound to closes the abnormal blood vessels. The condition disappears 24 hours after this procedure, but relapses 2-3 months later in nearly all patients. However, in a year-long treatment of Age-related Macular Degeneration study of 609 patients 16% of treated patients and 7% of placebo patients had visual improvement.
Attention to diet and lifestyle may help prevent or even reverse damage.
From a holistic perspective, one can think of this condition as at least partially due to the lack of essential nutrients and oxygen reaching the retina through the existing blood vessels in levels needed to support the retina properly. A healthy diet and lifestyle along with specific nutrient supplementation may help preserve vision by nourishing the retina and strengthening the integrity of the existing blood vessels.
Diet & Lifestyle Prevention Protocol - see our recommendations supporting macular health.
Daily juicing of vegetables and fruits (preferably organic). Our recipe for retinal support includes a combination of the following: ginger, garlic, leeks, parsley, beets, cabbage, carrots, celery, spinach, kale, collard greens, apples, grapes, raspberries, lemon, chlorophyll, and wheat grasses (but not too much fruit). Learn more about juicing.
- Macular degeneration (wet form)
- Pseudoxanthoma elasticum is a rare genetic disease which affects the skin first and then can affect the eyes when it causes dimples in the Bruch membrane that separates the choroid layer from the pigmented layer of the retina.
- In optic disc drusen neovascularization may occur.