To know why this power came back, regression or undercorrection - Your post operative records can clarify this, "Regression" presents as a slowly increasing power over a period of time after surgery. "Undercorrection" presents usually very soon after the surgery & pure undercorrection usually does not show progression. The other possiblity is continuing "progression" of your myopia. What is the cause, will it continue increasing - there can be several causes, but the important thing here is we can never predict which patient can face this issue before hand, so the doctors also don't have any means to predict progression or regression of power. Treatment options - there are several options & depend on mainly your vision & visual needs & your cornea topography status.

Regression is a well known phenomenon and may not reflect quality or care of surgery. It is a multi factorial problem.