I understand your feeling and also appreciate your concern towards your mother.
But with the diagnosis you have come up with it is related to the nerve of the eye. As nerve tissue has lowest regenerative power in the body. Once it gets degenerates it will not be regenerated back and am afraid that there is no treatment for optic atrophy. I cannot be stopped unless and untill it's cause is found out and treated.
So kindly take care of your mother.