Can vision reverse 5 months after PRK?

I'm 28 and had PRK on Sep 1, 2017. My vision hit 20/20 after one month and stay well since. But recently, my vision reversed a lot. Before PRK, I had a high prescription though -9.50 each. My doctor said vision reverse was because of dryness, and I kept using ointment and drops she recommended. Now, my dryness got better, but vision still blurry stays at 20/25 and 20/40. Why my vision doesn't recover after the dryness relieve? is it possible I got new prescription only after 5 months?