Immunosuppressive Treatment of Non-infectious Uveitis: History and Current Choices

Non-infectious uveitis is one of the leading causes of preventable blindness worldwide. Long-term immunosuppressive treatment is generally required to achieve durable control of inflammation in posterior and panuveitis. Although systemic corticosteroids have been the gold standard of immunosup- pressive treatment for uveitis since first introduced in 1950s, its side effects of long-term use often warrant an adjuvant treatment to reduce the dosage/duration of corticosteroids needed to maintain disease control. Conventional immunosuppressive drugs, classified into alkylating agent, antimetabolites and T cell inhibitors, have been widely used as corticosteroid-sparing agents, each with characteristic safety/tolerance profiles on different uveitis entities. Recently, biologic agents, which target specific molecules in immunopathogenesis of uveitis, have gained great interest as alternative treatments for refractory uveitis based on their favorable safety and effectiveness in a variety of uveitis entities. However, lack of large randomized controlled clinical trials, concerns about efficacy and safety of long-term usage, and economic burden are limiting the use of biologics in non-infectious uveitis. Local administration of immunosuppressive drugs (from corticosteroids to biologics) through intraocular drug delivery systems represent another direction for drug development and is now under intense investigation, but more evidences are needed to support their use as regular alternative treatments for uveitis. With the numerous choices belonging to different treatment modalities (conventional immunosuppressive agents, biologics and local drug delivery systems) on hand, the practice patterns have been reported to vary greatly from center to center. Factors influence uveitis specialists' choices of immunosuppressive agents may be complex and may include personal familiarity, treatment availability, safety/tolerability, effectiveness, patient compliance, cost concerns and suggestions from related specialists such as rheumatologists and pediatricians. The focus of this review is to provide an overview of each treatment modality on safety/tolerability and effectiveness, which are believed to be the two most important factors affecting treatment decision making.