What can you expect after a diabetic retinopathy surgery?

Depends: It depends on what type of surgery one had. Was it for a hemorrhage or retinal detachment? I will guess that the best of outcome in any type of surgery would be slowing the progression of the disease. There may be some improvement in vision, but this is hard to predict, again depending on the condition and the type of surgery and the presence of other comorbidities.

Need more info: What kind of surgery: laser, vitrectomy with or without gas injection, etc.? What was the exact diagnosis: vitreous hemorrhage, diabetic macular edema, prolifertive diabetic retinopathy, etc.?