The presence of breast implants does not affect the function of the breast tissue, and therefore should not affect milk production. If you have previously nursed a child you should be able to do so again following breast augmentation. If you do not yet have children you do not know how successful breast feeding will be for you. However, breast implants will not affect whatever ability you would otherwise have to breast feed. The implants themselves do not block the lactiferous ducts.
If the breast augmentation is performed through a peri-areolar incision, the incision itself, may damage a few lactiferous ducts but this should not be significant enough to alter milk production. When performing breast augmentation through a periareolar incision, some surgeons may divide a portion of the breast gland. Depending upon how this is done, some additional duct division may occur and this may alter milk production to some extent. This would be an important point to discuss with your plastic surgeon.
Best wishes.