Some things in life you just have to live with.
There are millions of people that would love to change their pictures. My wife is one of them. She has that "Stop me before I kill again" look.
Unless you have had MAJOR changes in your appearance, weight loss or gain in excess of 75 lbs., facial reconstruction, sex change, etc, there is no need to have your picture changed. If you do you would submit it the same way as a renewal.
There are a number of points that are used to identify the individual. The distance between the eyes, cheekbones and facial structure, not just the overall look of the face. Immigration officials aren't really looking at you but at those features so don't worry too much.