Spiker, I agree with Paulina , the chances of any remission/reverting the opaqueness are dependent on the length of time since diagnosis and length of time of the cataract formation. When I had my cataract removed I had to get my HbA1c to 7 before they would consider doing it so that delayed surgery by quite a time. I did have proliferative retinopathy too so one of the main risks was the greater chance of a bleed following surgery.
It's a hard call as obviously you want the best sight possible but also you really don't want to increase the risks of any complications with a non optimal HbA1c.