In patients with suspected uveitis, determining which test to do is a very specialized matter that must be professionally advised by the doctor and not by the patient. Objectively speaking, most ophthalmologists are not able to accurately determine which tests to perform. It is recommended that the patient conduct a search to find an ophthalmologist with experience in the treatment of uveitis who can give more professional advice and treatment. What is the process of laboratory testing? Laboratory testing is done mainly by taking intraocular fluid and the process is simple (Figure 3). Before doing the intraocular fluid aspiration, the doctor will give the patient some antibiotic eye drops every half hour, followed by surface anesthesia after 4 to 5 times. Anesthesia is also administered by means of eye drops, every five minutes, and three drops are usually enough. The doctor performs a microscopic puncture of the eye to extract the intraocular fluid, about 0.1 ml is sufficient. After the extraction, the patient is instructed to also use antibiotic eye drops frequently, every half hour, which usually lasts until the same night when they can be stopped. I have personally performed more than 3,000 intraocular fluid punctures to date without any complications. Where is the fluid taken for routine puncture of intraocular fluid? For laboratory testing of intraocular fluid, the specimen comes from two main sources (Figure 4): first, the anterior chamber fluid of the eye, which is the fluid between the cornea and iris; and second, the vitreous fluid is extracted. The test to determine the cause of uveitis by the gene chip method can produce results in as little as one hour. Other tests such as inflammatory factors and neovascular regulatory factors usually take three to five business days to complete. Are intraocular fluid puncture tests risky? In theory, performing an intraocular fluid puncture may cause misuse of the intraocular tissues or bacteria entering the eye and causing inflammation. If performed by an ophthalmologist who is experienced in the procedure, the risk is still relatively low. In addition, antibiotic eye drops will be given to the patient before and after the puncture, also to prevent increasing the chance of infection. Moreover, the puncture is performed under a special slit lamp (equivalent to a microscope) for ophthalmology, so that the site and depth of the puncture can be accurately grasped and the risk of accidental injury is greatly reduced. What is the accuracy of the laboratory test results? The accuracy varies slightly from test to test. The accuracy of virus detection by PCR technique is basically 100%; the accuracy of ocular archaeoplasmosis detection by taking vitreous fluid is also close to 100%; the accuracy of determining whether lymphoma is present by testing the ratio of interleukin 10 to interleukin 6 in intraocular fluid is 94% as reported in the literature;. We also summarized more than three hundred cases of lymphoma patients who had been tested previously, and the accuracy rate was 94%; or more. How should physicians and patients view the laboratory test reports correctly? Laboratory tests, like other tests, are diagnostic aids. It is recommended that the physician and the patient get the lab report and make a comprehensive diagnosis by combining the patient’s condition, medical history and other ancillary tests. All tests cannot be guaranteed to be 100% accurate every time, and technical or machine problems may affect the results.