Screen reader for blind people

A friend of mine is blind. He reads books and documents using Acrobat Reader and a speech synthesis, scrolling the text line by line with the arrow down button. Now he bought an e-book and to read it he's forced to use Adobe Digital Editions, but with this tool the arrow down button makes it jump to the next page, there is no way to scroll the text line by line: can you introduce this feature that could be very important for blind people?