Honestly, Emily, as you really want to get your A1c and blood levels down, my view would be that by far your best and quickest way would be to cut carbs. Zand hasn't needed to, but Zand's path is not a typical one, and you have no time to lose because you want to support your eyes NOW.
Get the Dr Bernstein book. It's a lifesaver. It's turned my dianetes around, and for many, many - look on the forum.
His method is to cut carbs down to 30g total a day, **because low carb intake gives you consistent blood sugars.** It's his Law of Small Numbers. So no more swings high/low, hypo risk much smaller. And if you do it, he argues that many D complications are reversible.
You have to watch your BG levels, of course, and lower insulin doses as necessary.
If you don't have time to lose, I'd not waste time on anything else.
Best of luck, Lucy