Hello. I hope you have found the answers you needed by now. if not, here are a few more..
My son has gone under GA more than a dozen times and no side effects so far. The GA is necessary for the MRI. We waited 10 months to have the MRI and I am so glad we finally did. Knowledge of either having SWS or not puts you at ease. Not knowing is very hard.
It is not necessary to have GA for the glaucoma test. With a somewhat willing baby and a patient provider, it can be done. That being said, I have an unwilling baby and have had the test done while he was under GA for a laser treatment.
I know there are good dermatologists in Europe who do treat very early, but do not know their names. if you would like more info, send me a PM and I'll look into it for you.