Hi MMP,
I think John is correct. There are so many factors involved, it's tough to put the finger on one of them. The research I have done on retinal detachment came up with a few published papers that seemed to indicate a connection between Avastin injection and possible retinal detachment. Otherwise, sometimes messing with the eye does it, or a blow to the head, or nothing at all.
The pulling of the vitreous sack away from the retina does put traction on the retina. Most people weather the process as they grow older and never have a retinal detachment. It's only us diabetics who are lucky enough to have neovascular growth into our vitreous. VEGF causes it because our retinas are not getting enough oxygen due to poor circulation. Good control lesssens the possibility that this will happen.
My ggmother, my grandpa's mom is the only other diabetic in our family. She died when I was very young, before the onset of my diabetes. She was "blind." She described her blindness to my mom as "like looking through heavily smoked glass." That sounds to me like she had neovascular growth that ruptured and that if they had known how to do vitrectomies in the 30's and 40's, she probably would have been able to see. It also tells me that there may be a genetic component involved in my diabetic eye problems.
There are many people on this board who have had vitrectomies and have had excellent results with no complications. I think my outcome was pretty rare. Also, I'd like to point out I'm still reading and painting, albeit with glasses and bright lights.
You've mentioned your annoyance with floaters enough times that they seem like a problem for you. Your chances are very good to have an excellent outcome, but of course we never know. If I were you, I'd probably get them fixed if the doctor says he/she thinks it will be a good long term result. The doctor has seen lots of these, I've seen only three

.
Deep breath. Go outdoors and look at some trees. Breathe. I know the time before any medical procedure is nerve-wracking.
Here's another hug.
Mich