Carbonic anhydrase inhibitors

I have been told by my ophthalmologist that I will likely be placed on a carbonic anhydrase inhibitor (Neptazane or methazolamide) for the rest of my life to treat a retina condition. I am 52 yrs old, in otherwise good health. I have taken 50 mg twice a day for several months. I feel no side effects. However, I routinely have extremely cloudy urine. When I come off the Neptazane, this phenomenon goes away. I have had kidney stones in the past. I know this drug alters the acid/base balance of the body. Should I worry about long term use of this drug? Should I be evaluated or monitored for effects on my kidneys?