Vitreous cavity injection of medication is an important way to treat diabetic macular edema. Preparation before injection of medication, and care after injection, are important factors to ensure the efficacy of the treatment. Today, we will list out the issues to pay attention to before and after the drug injection, so that patients can fully understand and fight a prepared battle. To what extent does diabetic macular edema require drug injection? For diabetic macular edema, whether laser or injection is invasive treatment, it will bring certain risks, and it needs to be clear that the patient’s condition has reached a certain level before such a treatment plan can be taken. Generally, patients are required to have a retinal thickness of 250 microns or more in the macula and a visual acuity of 0.5 or less before they are considered for vitreous cavity injection treatment. However, other factors such as the physician’s analysis of the progression of the disease, assessment of the lesion’s threat to vision and the patient’s receptiveness to treatment must also be taken into account. Can both eyes be treated with drug injections at the same time? Currently, our guidelines indicate that vitreous cavity injections are not allowed in both eyes at the same time, especially for anti-VEGF drugs, which should be injected at least one to two weeks apart in both eyes. This is because although the anti-VEGF drug is injected into the eye, it can be absorbed into the whole body through the blood vessels. Unlike the eyes, our heart and brain vessels need a certain concentration of VEGF to maintain normal metabolism, especially for elderly people with cardiovascular lesions, the production of new blood vessels can restore the blood supply to the heart and brain, once the concentration of anti-VEGF in the body is too high, it will easily cause cardiovascular accidents in elderly patients. Therefore, simultaneous injection into both eyes is not recommended, and monocular injection treatment can mitigate this risk. Can intraocular injections be performed on the same day as the outpatient clinic? Intraocular drug injections need to be scheduled in advance. For patients with suitable conditions, the doctor will contact the operating room and set a time for the injection once the treatment plan is determined. Patients should order antibiotic eye drops three days in advance to prevent infection. When the appointment date arrives and the patient signs an informed consent form, the medication is injected as scheduled. Many patients are particularly anxious to have the injection the same day they are seen, which is not acceptable. First, diabetic macular edema does not form in one day, although it is very serious, it is not a problem to prepare for three days. Second, if the injection is done in a hurry without preparation, it may raise the risk of endophthalmitis and vitreous cavity hemorrhage. How should the patient cooperate when the drug is injected? The entire injection process is very short, only 20 to 30 seconds, just like a normal injection, and many patients hardly feel anything, but a high degree of patient cooperation is required. The patient’s injection eyes should be fixed on a certain place and should not be turned randomly, otherwise the doctor cannot aim; in addition, the eyes should not be closed hard, and the injection site should be fully exposed to facilitate the doctor’s stable operation. Before injecting the drug into the vitreous cavity, the doctor will give the patient a few drops of eye drops for ocular surface anesthesia, so that the patient will not be in pain during the injection, so there is no need to be too nervous. How do I care for my eyes after the injection? After the injection of medication into the vitreous cavity, the doctor will give the patient a dab of anti-inflammatory ointment and cover this eye with gauze, which will be opened the next day and the eye medication will be continued. Antibiotic eye drops are usually used routinely for 3 days after surgery, and no other medications are usually necessary. It is important to note that washing the face is not recommended the night after the injection because of the gauze covering; the next day you can wash your face, watch TV and read normally; because of the needle eye, patients are not advised to take a shower or wash their hair for 3 to 5 days after the injection to ensure that dirty water does not flow into the eye and cause infection. After the injection, what symptoms should be seen in time? It is important to return to the hospital once a week after the injection of the drug to check for signs of infection and bleeding. During this period, if you experience eye swelling and pain that persists for a long time without relief and significant loss of vision, you need to come to the outpatient clinic immediately for a review to rule out infection and other problems. Of course, it is normal for some patients to have some grinding pain in their eyes after surgery. First, because there is a needle eye, about half an hour to an hour after the injection, there will be some grinding pain after the effect of anesthetic drugs wears off; second, the anesthetic drugs will make the corneal epithelial cells fall off, and the disinfectant solution will also have some damage to the corneal epithelium, so the patient will feel the rubbing sensation like sand in the eye, and even have some soreness and tears. Usually this symptom will be completely fine the next day, so there is no need to be too nervous. If it is persistently bad, you should also come to the hospital for a visit. What information do patients need to upload after scanning the code report? Why? The treatment of diabetic macular edema is a long-term process, therefore, patients and doctors need to have a stable contact to facilitate the development and changes of the disease and to formulate an effective treatment plan in time. A convenient and effective way for patients to connect with their doctors is through WeChat. After patients report to the doctor by scanning the code, they need to upload two test results, one is OCT (optical correlation tomography), which serves to determine the degree and type of macular edema, and the thickness of the retinal macula is measured by OCT. There is also fluorescence angiography, which can determine the extent of macular edema and its cause. However, because fluorescence angiography is an invasive test, OCT is often done to observe the condition for patients who have a review, and it is easy to operate. Uploading this information helps doctors to judge the condition, and for patients who consult online, it is convenient for doctors to give more instructive advice. Moreover, there are more ophthalmic examinations, which are easily lost, and can be saved permanently after uploading.