There is only one drug on the market for macular degeneration , and it is approved to treat only one subtype that represents a minority of cases .
There is one drug on the market for macular degeneration , Visudyne , and it is approved for the treatment of only one subtype that represents a minority of cases .
branch of math that deals with uncertainties by simulating process of human reasoning.  - based on degrees of truth rather than &"true or false&"