Autologous Serum and Serum Components.
Dry eye syndrome is a multifactorial condition on the tear and ocular surface. Autologous serum eye drop is an effective method for treating dry eye. Autologous serum eye drops are now widely used by specialists since a first report in 1975. The results of a systematic study showed that the efficacy of autologous serum eye drops remains ambiguous because its preparation methods and clinical application have not been standardized. To elucidate the efficacy of autologous serum eye drops, well-designed, large-scale, high-quality randomized controlled trials need to be conducted with standardized treatment and use. Since serum components are partially similar to tear components, autologous serum eye drops improve dry eye by supplying tear components such as growth factors, proteins, and vitamins. Adding to the evidence based on the treatment of dry eye, we have found a new treatment candidate from serum: selenoprotein P (SeP). The efficacy of SeP as a treatment for dry eye was revealed by applying SeP eye drops to a dry eye rat model. Compared with phosphate-buffered saline treatment, SeP eye drops significantly reduced the fluorescein score of the cornea and suppressed the oxidative stress in the cornea, which is related to onset of dry eye, leading to improved corneal disorder. We have developed a new dry eye model caused by oxidative stress that will be used to screen candidate molecules for antioxidative activity.