How much it takes from the installation of macular degenerescence till the complete or severe blindness?

I believe that you will never go completely blind with it.My mother has it and it hasn't deteriorated in the last 3 years.My mother in law went about 10 years from being diagnosed to going blind although she could still from the corner of her eyes.Her aunt went over 10 years before her sight was very bad.There is an operation for the one type of macular degeneration