This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Vitreous and retina, Subject name: Ophthalmology
Proliferative diabetic retinopathy is treated by 
Select and explain. 
A. Pan retinal photocoagulation, B. Pars plana vitrectomy, C. Grid laser photocoagulation, D. Focal retinal photocoagulation
A: Pan retinal photocoagulation
Answer: A: Pan retinal photocoagulation 
Explanation: Panretinal photocoagulation (PRP) is the preferred form of treatment of proliferative diabetic retinopathy(PDR). ... In cases where macular edema and PDR coexist, laser treatments are performed: first, laser treatment is used for the macular edema; then for PDR, the PRP is spread over 3 to 4 sessions Ref AK khurana 6/e p278