AMD is an eye disease that occurs when the macula, the small central portion of the retina, wears down. This condition is more prevalent as people start aging, and although it rarely leads to total blindness, it can cause severe vision problems.
Photodynamic therapy (PDT) is usually used to treat wet AMD and is never used to treat dry AMD. Although this treatment is rarely used since new drugs are being used to decrease the abnormal growth of blood vessels, PDT can be used alongside these other medications, or it can be used if the drugs or injections fail to work.
Although PDT cannot restore lost vision, it is used to slow down the damage of the central vision. PDT uses a light-sensitive medicine known as Visudyne (verteporfin), which is injected into the bloodstream through a vein in the arm. The medicine then collects under the macula in the abnormal blood vessels. The eye is then exposed to laser light, causing the medicine to activate and create blood clots to block the abnormal blood vessels. The central vision loss slows down when the abnormal blood vessels are sealed off.
Since it is likely for more blood vessels to grow, patients may need multiple photodynamic therapy treatments later on.