2lizjohn, your frustration is understandable. It's somewhat puzzling why the ER dr didn't order the MRI while you were there, but your primary care provider can certainly do that. From my mother's experience, a TIA would not always show up on an MRI, but she had classic symptoms. Seeing white was not one of those. Not to confuse you or frustrate you further, but I wonder if you might want to contact an opthalmologist. I did that when everything in my world turned black. No cause was found at that time, howeverI felt bette r knowing she could see the nerves in my eyes and if there had been a concern, she would have followed through with treatment. Reason I return every 6 months, especially now that I've had a stroke.
I sincerely hope your frustration subsides and you can get the care and help you need.