Today I asked my retinal specialist exactly what it was that was being zapped during my laser treatments, because I've always wondered and never got a really straight answer from any source.
It's kinda complicated, but in language those of us who aren't retinal specialists can understand, he said that because my retinal tissue isn't getting enough oxygen, it sends the signal to the brain to make more blood vessels. These are the vessels that are weak and leak easily and really serve no purpose to the retina. So, he's zapping the retinal tissue in the peripheral areas and killing it. (I had always thought he was zapping something "new" that had developed because of the retinopathy, but he's actually zapping regular retinal tissue.) This means that the retina requires less oxygen, so the signals to make new blood vessels are no longer being sent to the brain. Essentially, the peripheral tissue is being sacrificed to save the tissue at the centre that is more important to my vision.
Anyway, that's the quick and dirty version, in case anyone other than me was also wondering.
