However, abnormal increase of VEGF can cause high leakage of blood vessels and neovascularization in the macula. As neovascularization is brittle, it is prone to bleeding, leakage, edema, and eventually scarring, resulting in blindness. This factor is mainly increased in the following diseases: macular degeneration, diabetic retinopathy, retinal vein occlusion, and anti-VEGF drug therapy aims to reduce leakage, reduce edema, and thus stabilize or improve vision. Since macular degeneration, diabetic macular edema, or venous obstruction are all chronic diseases, current treatment cannot cure them. Anti-VEGF medication, in general, controls the progression of the disease and often requires multiple treatments, although some diseases such as simple macular edema may require fewer injections. Possible complications of intraocular injections The greatest risk of intraocular injections is the complications associated with the injections, such as: intraocular infection, hemorrhage, and retinal detachment. In addition, complications such as retinal pigment epithelial tears have also been reported. One of the most important complications is intraocular infection, which can have serious consequences and may lead to blindness, but the incidence of this complication is low, with an incidence of about 0.1% reported abroad. The side effects of the drug itself are not significant. Preparation before the injection Antibiotic eye drops should be administered 3 days before the proposed injection. If eye drops cannot be administered 3 days in advance, eye drops should be ordered intensively, for example, once every 5 minutes, and only then can the injection be given. You need to be accompanied on the day of injection, and it is generally not recommended to inject both eyes at the same time. On the day of surgery, after signing the consent form for surgery, you will enter the operating room. In the operating room, the eye is disinfected, surface anesthetic is ordered, and the medication is injected into the eye at 3.5mm from the corneal edge. Post-operative precautions The gauze can be opened on the night of surgery, and antibiotic eye drops are ordered 3-4 times before going to bed, and the face is not washed that night. Starting from the first day after surgery, eye drops should be ordered for at least 3 consecutive days, at least 4 times a day. However, if you have obvious eye pain, obvious blurred vision, or red and congested eyes, you should contact your doctor immediately, or visit the ophthalmology department of your local hospital, mainly to find out if any infection has occurred. Possible post-operative conditions: 1. flocculent floating objects in front of the eyes after surgery: it may be the drug floating in the vitreous body, no need to be nervous, it will disappear within 2-3 days. 2. bleeding in the eyes after surgery, this may be the injection of small blood vessels bleeding, usually about 10 days to absorb. 3, the day of surgery to go back to the eye is very painful, a lot of tears, foreign body feeling: may be the role of disinfectant, if indeed the pain is not tolerable, you need to come to the hospital to see; such as still tolerable, usually the next day can be relieved. Photodynamic therapy (PDT) combined with intraocular injection of drugs for macular neovascularization PDT was the only treatment for intraocular neovascularization before the advent of anti-VEGF drugs, and it is really effective to close the neovascularization and stabilize the vision. Another great benefit is that there are essentially no side effects or complications, and the number of treatments is low. In some cases, both good results can be achieved with PDT treatment alone. Depending on the condition, we have used PDT in combination with intraocular injections in some patients to treat intraocular neovascular disease, especially polypoidal choroidal vasculopathy, with better results and significantly reduced the number of intraocular injections, thus greatly reducing the financial burden and the risk of intraocular injections for patients. We must realize that due to the limitation of current medical level, not all patients can achieve satisfactory results after treatment, especially the macula is the most sensitive part of human eye vision, its structure is fine, once the hemorrhage and edema occurs in this area, the impact on the visual function is very serious, even after treatment, some visual function can not be fully returned to the pre-disease state, in addition, for serious conditions, the macula has scarred or atrophied, the effect of treatment is very good. If the macula is scarred or atrophied, the effect of treatment is limited.