Wet Macular Degeneration, also known as the exudative type, is the more severe of the two types of AMD or Age-related Macular Degeneration, which cause 90% of blindness from the disease but only accounts for 15% of AMD cases. Wet macular degeneration develops when new blood vessels, known as choroidal neovascularizations (CNVs) grow from the choroid underneath the macular portion of the retina. These abnormal vessels may leak fluid or blood causing the central vision to blur, as the macula begins to bulge or lift up. Under these circumstances, vision loss may be rapid and severe. This exudative form of macular degeneration may also show signs of the dry form. Due to fluid accumulation, patients of the Wet form of AMD may see dark spots in the center of their vision. Moreover, straight lines may become wavy or crooked since the Macula is no longer smooth. Peripheral vision is not affected most of the time. The Wet form of Macular Degeneration may also result in legal blindness, defined as 20/200 vision or worse. A failure in the waste removal system of the RPE or retinal pigment epithelium cells (similar to that of Dry AMD) is thought to be the reason behind the abnormal growth of blood vessels. Lack of nutrients may also contribute to this abnormality but that is still under scientific scrutiny since no conclusive evidence has been revealed. The most plausible theory at this time is that when the membrane underlying the retina thickens and breaks, the oxygen supply to the macula is disrupted and the body responds by growing new, abnormal blood vessels. |
