Is There a Procedure to Decrease Space Between Breasts?

Post-operative cleavage will depend on your pre-surgery cleavage. You have wide-set breasts, which means you'll probably continue to have wide-set breasts after surgery. However, while you may have a bit of improvement, it may not be as much as you want. Unfortunately, your surgeon can only do so much to give you cleavage before it looks abnormal, since the implants have to remain centred underneath your nipples.  At the moment, your best option would be to buy a pushup bra.

I would not rate your aesthetic appearance as severely as you describe. Tthe bra you have does demonstrate a reasonable cleavage. Of course there are other bra styles which may help in this regard. Some of my patients prefer the "extreme cleavage" line of bras by Fredericks of Hollywood.

Laetitia,
Women, like men, come in all shapes and sizes. If your natural breast position is wide set on your chest, it may be difficult to have cleavage.
I tell breast augmentation patients that if their natural breasts do not easily come to the middle, it is possible they will not be able to after augmentation, especially with implants placed under the muscle.
You could always see a board-certified plastic surgeon in your area so they could examine you and review your options.
Best of luck.
Dr Edwards