To avoid diabetic retinopathy, what should you do?

Can be avoided. Just like any other diabetic co-morbid risk, ideal control of blood sugar, see your ophthalmologist yearly.
Control glucose. By far the best way is to control glucose. A decrease in hga1c from 8.0% to 7% will decrease the chance of developing diabetic retinopathy by 50% according the the wesr study.
Regular follow up. Regular follow and good sugar control. Some recommendations are the following in children with diabetes initial exam: age 10 years (or after 3-5 years of diabetes mellitus) subsequent exams: annually . In adults with type 2 diabetes initial exam at diagnosis subsequent exams: annually.

Related Questions

My grand and greatgrandparents had diabetic retinopathy. How can I avoid it?

Luck/treatment. The inheritance of diabetes is not direct and hopefully you do not get it. If you are found to have this condition, then you need to every day pay attention to management of the blood sugar and the medication you will be placed upon. Retinopathy mostly occurs in those with poor control but a few get it anyway. It is treatable however. Good luck. Read more...
Don't get diabetes. If you already have diabetes, keep your A1c close to 6.5%, blood pressure less than 130/80, and get on an ace inhibitor or arb medication. Read more...