There is no specific clinical value for the probability of macular edema from retinal laser photocoagulation. It is only clear that patients undergoing retinal laser photocoagulation have a higher risk of macular edema. This occurs mostly due to the presence of lesions in the retina itself, which have structural or functional abnormalities that may cause a decrease in resistance when the retina is exposed to external stimuli, thus causing macular edema. For example, in patients with diabetic retinopathy, due to long-term metabolic abnormalities, the retina itself may have vascular endothelial cell dysfunction, and when stimulated by the laser, the permeability of capillaries will increase, and the blood-retinal barrier will be damaged, which will lead to edema.