Re: tetrinoin made my shallow scar worse!
I think Retin A is useless for scars. Thats my 2 cents. I have scarring from teenage acne that has never gone away. I remember reading about a UCLA(?) study of Retin A on scars and although the results were preliminary with intent to study more, they found that if anything it deepened scarring.
Aside from that, I've personally found it very useful in eliminating tiny lines on the face and stimulating collagen to a degree.
The only other thing you could probably do is Mederma? I've not tried that for scarring and it has been used for post-surgery scars, bites and such. Another alternative is a facial filler from a plastic surgeons office.