Uveitis must be treated individually. Uveitis is a general term for a group of diseases that encompasses more than one hundred different diseases, such as various retinal vasculitis, Koyanagiharada disease, Leukoarai disease, etc. Therefore, the treatment is different for different types and causes of uveitis. For example, cytomegalovirus retinitis requires antiviral drugs to control inflammation; if the uveitis is caused by autoimmune diseases such as rheumatoid arthritis and lupus erythematosus, it needs to be treated with glucocorticoids or immunosuppressive drugs. What are the consequences of treating uveitis with the wrong medication? If uveitis is treated with the wrong type of treatment, it is as likely to have disastrous consequences as it is to go south. For example, in uveitis caused by bacteria, the immune system is already unable to defend itself against the invasion of bacteria, and treating it with glucocorticoids or immunosuppressants will further reduce the immune system’s ability to fight the bacteria, adding fuel to the fire. The patient’s vision may gradually decrease from a few days to a rapid decrease within a few hours, and the patient will soon be blind, or in severe cases, may not even be able to keep his or her eyes. If a patient has uveitis caused by an autoimmune disease, but antibiotics or antifungal drugs are used, they will not cause too many side effects, but they will delay treatment and cause the disease to progress. In other words, the treatment of uveitis starts with identifying the cause of the disease. The diagnosis of the cause of uveitis is very important. The culprit causing the inflammation is not the same and the treatment varies widely. Do all patients with suspected uveitis need to have an etiologic diagnosis? It is generally important to determine, based on a variety of evidence, exactly what is causing the uveitis. This evidence consists mainly of a medical history and various examinations and laboratory tests. By taking a medical history, it can give the doctor a general direction. If the patient has suffered trauma, the doctor will suspect bacterial or fungal infection as the cause; if the patient is immunocompromised, such as the AIDS population should suspect cytomegalovirus retinitis, patients on long-term oral immunosuppressive drugs after organ transplantation should consider endophthalmitis, etc. In addition to the medical history, the ophthalmologist will further clarify the diagnosis through eye examinations, including slit lamp and fundoscopy. The site and pattern of the lesion are looked at and considered in conjunction with the degree of urgency of the disease. For example, uveitis caused by bacteria is more acute, while fungal causes are relatively slower and less painful. In addition, the ophthalmology laboratory at Peking University People’s Hospital conducts tests for intraocular fluid. The test is able to directly find out which bacteria, virus or other inflammatory factors, etc. are causing the uveitis so that it can be treated symptomatically. Currently, this test is not performed elsewhere. Are there other ways to diagnose the cause of uveitis? In addition to history, routine ophthalmologic examination and laboratory testing of intraocular fluid, systemic examination and laboratory tests can also help the doctor determine the cause of uveitis. For example, uveitis caused by syphilis can be diagnosed with a serum test for syphilis spirochetes, and uveitis caused by tuberculosis can usually be diagnosed with a chest radiograph and a tuberculosis dermatophyte test.