I disagree. Glaucoma does not have this type of presentation. I still feel it is an aura due to migraine. You have described the textbook presentation of it.
However, I would still recommend you have the back of your eye looked at to rule out any retinal problems (such as a tear or hole).
But I do feel strongly that it is related to your migraines.
Hope this will ease any worry that may have just been caused :d