PDR cases are treated by full scatter PRP. Some cases have non-regressing neovascularisation were before treated by peripheral cryopexy, in the anterior retina. In our thesis we studied the effect of using diopexy instead of cryopexy,since several complications of cryopexy were reported. Results showed that diopexy is useful in regression of posterior segment neovascularisation and stabilizing the PDR eyes, help in regression of rubeosis, and in cases of recurrent vitreous hemorrhage, help reabsorption of hemmorrhage.