Age-related macular degeneration, often called AMD or ARMD, is the leading cause of vision loss and blindness among Americans who are age 65 and older. AMD is degeneration of the macula, which is the part of the retina responsible for the sharp, central vision needed to read or drive. Because the macula primarily is affected in AMD, central vision loss may occur. Macular degeneration is diagnosed as either dry (non-neovascular) or wet (neovascular).Neovascular refers to growth of new blood vessels in an area where they are not supposed to be.
Dry AMD is an early stage of the disease and may result from the aging and thinning of macular tissues, depositing of pigment in the macula or a combination of the two processes. In about 10 percent of cases, dry AMD progresses to the more advanced and damaging form of the eye disease. With wet macular degeneration, new blood vessels grow beneath the retina and leak blood and fluid. This leakage causes permanent damage to light-sensitive retinal cells, which die off and create blind spots in central vision. Choroidal neovascularization (CNV), the underlying process causing wet AMD and abnormal blood vessel growth, is the body’s misguided way of attempting to create a new network of blood vessels to supply more nutrients and oxygen to the eye’s retina. Instead, the process creates scarring, leading to sometimes severe central vision loss. Whether two drug treatments Lucentis and Avastin, are equally effective in treating wet AMD has always been a topic of research. Trials such as IVAN and CATT are working in this direction.
It can be said that there is no functional difference in the effects of both drugs and that the effects of Lucentis and Avastin on preventing vision loss are similar. Also giving the drugs as needed, compared to regularly every month, results in almost identical levels of vision. Hence, Lucentis and Avastin have similar effectiveness. Regardless of the drug received, or treating monthly or as needed, sight in the affected eye improves by between one and two lines on a standard eye test. Both IVAN and CATT consistently show no difference in mortality between the groups receiving different drugs in the elderly but both find a slightly higher rate of other serious adverse events in those who receive Avastin. adverse events may not be attributed to Avastin directly due to a number of reasons, including that events are more common in patients treated less frequently, and that they arise mainly from hospitalizations for a wide variety of causes not previously associated with either drug.