Incidence of Macular Edema After Panretinal Photocoagulation (PRPC) Performed in a Single Session Versus Four Sessions in Diabetic Patients.

Inclusion Criteria: * Diabetes type 1 or 2 * Subjects with severe non-proliferative or early proliferative diabetic retinopathy (according to the Alfediam classification) * Subjects with central macular thickness less than or equal to 350 µm according to spetralis OCT * Subjects registered with a social security agency * Subjects who have provided written informed consent * Subjects aged 18 or above Exclusion Criteria: * Pregnancy * Breastfeeding women * Patients presenting a contra-indication to Mydriaticum and Neosynephrine * History of glaucoma or non-controlled ocular hypertension * Blindness in one eye * History of renal insufficiency requiring dialysis, or kidney or pancreas transplantation * Unbalanced diabetes requiring, in the previous 4 months, intensive insulin therapy. * Central macular thickness greater than 350 µm * Visual acuity less than 20/32 measured using an ETDRS chart * Proliferative diabetic retinopathy associated with "high risk factors" (extensive prepapillary neovessels and/or preretinal or prepapillary neovessels associated with preretinal of intravitreal hemorrhage) * Macular edema due to causes other than diabetic retinopathy (venous occlusion, uveitis) or occurring in a context of vitreomacular traction * Already started PRPC * History of eye surgery or YAG laser capsulotomy performed during the preceding 6 months * Subjects under legal supervision or guardianship