How is laser treatment for diabetic retinopathy? Some patients are concerned that laser treatment is a destructive treatment, so are there any side effects? The main cause of diabetic retinopathy is the ischemia of the entire retina due to microcirculatory disorders and vascular occlusion, and the nerve cells of the retina begin to die irreversibly due to ischemia, so a compensatory mechanism of the human body secretes something called neovascular growth factor. The purpose of the laser is to ensure that the remaining retinal cells are adequately vascularized and that the central vision is preserved at the expense of the peripheral vision. In principle, this involves hitting 900-1200 light points on the retina. Since after a certain number of dots are hit (around 300-400 dots), the stimulation of the laser starts to cause pain to the patient, and also if more dots are hit, the retina may become edematous because it is damaged too much at once, leading to vision loss. Therefore, it is usually necessary to have the laser in one eye in stages, once every week, for a total of 3 to 4 times. The laser is necrosis of the retina other than this part where we see the most clearly, so almost all of the retina except the area where the macula is located will be hit by the laser, resulting in the eye seeing less, with dark spots, spot shadows, and also, since the peripheral retina that is hit by the laser has no visual function in normal times, it is useful to see in dark conditions, so it is also possible for patients to see in dark situations, such as at night or in a dark room, with reduced vision. Many patients do not understand how the laser works and miss the timing of the laser, resulting in progression to vitreous hemosiderosis, retinal proliferative lesions, and retinal detachment by traction. Laser treatment is destructive, but it inhibits retinal neovascularization, and the benefits outweigh the disadvantages.