Serum components to support corneal health - PROJECT SUMMARY For almost 50 years, blood-based therapies, such as autologous serum tears (ASTs), have been used in clinical ophthalmology to treat diverse ocular surface disorders including Sjogren's syndrome-related dry eye disease, persistent epithelial defects, chemical injury, recurrent erosion syndrome, superior limbic keratoconjunctivitis, neurotrophic keratopathy, limbal stem cell disease, cicatrizing conjunctivitis, and post-corneal cross-linking haze. It is theorized that serum has components that either replace those missing endogenously or modulate pathways to restore healthy function. However, to date, there has been no detailed molecular characterization of serum tears in the context of ocular surface disease. The poorly defined mechanism of serum tears in treating ocular surface disease leads to two important challenges in their clinical application: (1) the lack of a standard concentration for preparation, and (2) the inconvenient and costly process of obtaining ASTs. Thus, despite many clinical studies that demonstrate the ability of serum tears to improve both objective signs and subjective symptoms of ocular surface disorders, formulation and accessibility issues have limited its more widespread use. Our overall objective is to define the combinations of serum components (growth factors, signaling lipids, vitamins, etc.) that support corneal repair. We hypothesize that the effects of serum tears are due a simple combination of bioactive factors, some of which remain to be characterized, or the result of synergistic actions of serum components. Our studies seek to determine bioactive serum tear components and define synergism between components, and characterize the in vivo effects of blood-based tears in an ocular surface disease model. We anticipate this project will yield both translational insight to the clinical use of serum tears, and likely improve current formulation and accessibility issues which may allow for more widespread use. Furthermore, the identification and characterization of bioactive serum tear components is expected to reveal potential therapeutic targets for further exploration.