Thanks for your question and as a dermatologist we routinely recommend retinoids as topical therapy for skin aging and photodamage. Fillers are injected deeper in the skin than most retinoids will penetrate and may enhance the results over time so find the right provider and learn all there is to learn about fillers and good skin care.
Tretinoin will not have any impact on fillers, but can be an important component of a good skin care regimen.