As far as I am aware, there are no solid studies on the issue. After all this time, the retina in the operated eye is likely very secure and stable, but the question is if the roller coaster ride could cause a retinal tear/detachment in the other eye. I would ask your retina surgeon, but I would say to avoid the thrill rides.
I am no Dr. but had scar tissue removal / vitrectomy 2 years ago. I have been on these forums for 2+ years and from what I've read from Dr. Hagan, etc. is that it is NOT a good idea to go on roller coasters with any sort of eye issue.
The G force pulls at the retina.
I went to Magic Mtn. in Calif. several months before my scar tissue formed and seriously think one of the monster coasters that went forward and then reverse extremely fast, had something to do with my retina damage. I actually blacked out when the coaster did it's reversal from the force.
It's up to you because I doubt if there are any real "studies" on this issue, but I know that after being partially blind in the one eye and the surgery, I sure wouldn't take the chance.
Good luck !