The causes of macular edema are numerous and different causes may be inter-related. It is commonly associated with diabetes. Chronic or uncontrolled diabetes type 2 can affect peripheral blood vessels including those of the retina which may leak fluid, blood and occasionally fats into the retina causing it to swell.
Visual C++. Visual C++ is known as a native development language, as it talks directly to the hardware for the Windows Mobile device, with no intervening layers (unlike Visual C#, for example). Programming using C++ can be challenging, as it is not a trivial language to learn.
tl;dr: C. If you need to write a new OS altogether knowing C is the best I would say. All the basic stuff (that is closest to the machine) is mostly written in C, knowing other high level languages like C++ will help at a higher level say when building a GUI etc. This might give you some idea, http://stackoverflow.com/questio...