I agree with Dr. Daniels that the asymmetry seen in the nipple is minimal. I suggest doing a little research and looking at pre and post operation photos to get an idea of how big of scars you will have for such a surgery. If your asymmetric nipples bother you, the scars may as well. Other than that, I suggest consulting in person with a board certified plastic surgeon to get the most accurate advice for your personal needs.
Jaime Perez, MD
Breast Augmentation Specialist
Plastic Surgery Center of Tampa
The degree of asymmetry between your breasts is relatively minor and any attempt to improve it would likely result in excessive scar burden. Be careful what you wish for....
You have many options to improve your symmetry, it just depends on what you like/dislike about each breast.