I had ick in my display earlier this year because I took at fish out of the QT too early. Anyway, my fish seemed to fight it off. I also noticed that the ick seemed to get weaker over time, maybe about 3 months. By weaker, I mean at first the fish were getting a lot of large spots. Over time, the spots were getting smaller, less frequent and the fish seemed less bothered by it.
I have an Aqua 57 watt. I change the bulb about every 9 months. The UV is not a cure. However, a UV may help reduce the free swimming ick but the fish will still get ick. It just spreads so quickly.