Uveitis can be broadly categorized into infectious versus non-infectious causes.  The largest number of uveitis patients fall into the non-infectious category.  Because of the  broad number of underlying inflammatory systemic conditions associated with uveitis, which can affect other parts of the body, your ophthalmologist may do lab testing, consisting of blood tests, skin test and x-rays, to look for underlying causes of the inflammation. Often, despite a thorough evaluation, laboratory results are normal and patients are otherwise healthy which means the inflammation can be treated symptomatically. 

Patients who have uveitis because they have an infection in other parts of their body, receive clinical evaluation and precise treatment with appropriate medications for the infection.