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.
C# is one of the languages that can be used in the .NET platform. Do not be confused about a programming language and the platform it uses. Any programming language in the .NET platform can be used to build desktop apps for Windows; build web apps; and interoperate in Linux. Currently there are no C# compiler that makes native Android apps.