I never calculate the success rate of PRK surgery. Perhaps only eye doctor can tell you the correctly answer. As far as I know, the PRK surgery today is easy to get and they have very high success rate. And if you will get successful PRK surgeon also depend on your eye condition. Therefore, if you anxious about the surgery, you shall consult your eye doctor or surgeon because s/he know better about your eyes.
It is said that the success rate of PRK surgery can reach 99% today. But I am not sure if it is works for you since I have no idea about your eye condition. Anyway, there are risks to take PRK surgery. And it is possible to get undercorrection or overcorrection etc. But these situations are really rare. So, donâ€™t worry and keep calm, you shall believe that most of people can get a success surgery, and you will be one of them.