Retinal specialist said i have suspicious optic atrophy and has referred me to a neuro. what are the chances of this being a brain tumor? im scared

Atrophy: This is usually from some process effecting the nerve directly or pressure. A tumor would be less on my list. However, you are in the hands of the appropriate specialists. If an MRI is warranted that would find the tumor if there is one. If there is a tumor addressing it early as possible is the best. I am glad you are taking the appropriate actions.