I am 76 years old and it took 3 years and a loss of 100 lbs before they diagnosed me with mac and Bronchiectasis. I started the big 3 last Aug and last month was taken off ethambutol by my eye specialist after failing my second eye field test. My immune Dr did concur with taking me off the med. But I did get good news that my second series of cultures have come back negative. This is after cultures coming back in the beginning positive for 3 different varieties of mac. Like they say everyone is different, but I think the meds did their job, but I have to admit I was very reluctant in taking them at first and had several side effects. Good luck in whatever decision you decide on.