Re: What about all the other diseases?
"Macular degeneration, for one."
What about them? This is a diagnostic device for screening for a specific condition. Complaining that it doesn't detect every possible illness in the world is just ridiculous. That makes as much sense as complaining that a blood test for ebola can't detect a sprained ankle. If you want a magic machine that can diagnose absolutely everything, you're in the wrong reality.
"And what happens if someone dies because of a missed diagnosis. Who do you prosecute then?"
No-one. Diagnoses are never perfect and should not be expected to be. Unless you have a good reason to suspect actual negligence or malpractice, you have absolutely no business thinking about prosecuting anyone. The insistence some people have on assigning blame every time doctors fail to be perfect in every way is probably the biggest problem faced by the medical profession.