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.
Simon Martin's answer is pretty spot on in relation to the specific advantages of C++ that make it the preferred language for implementing game engines. This doesn't necessarily make it the best language for game development. For instance, while Cryengine is written with C++a developer using Cryengine is likely to be using the LUA scripting interface. Unity is developed in C++, but as a developer you use C#.