A Comprehensive Proteomics Analysis of the Human Iris Tissue: Ready to Embrace Postgenomics Precision Medicine in Ophthalmology?

The annual economic burden of visual disorders in the United States was estimated at $139 billion. Ophthalmology is therefore one of the salient application fields of postgenomics biotechnologies such as proteomics in the pursuit of global precision medicine. Interestingly, the protein composition of the human iris tissue still remains largely unexplored. In this context, the uveal tract constitutes the vascular middle coat of the eye and is formed by the choroid, ciliary body, and iris. The iris forms the anterior most part of the uvea. It is a thin muscular diaphragm with a central perforation called pupil. Inflammation of the uvea is termed uveitis and causes reduced vision or blindness. However, the pathogenesis of the spectrum of diseases causing uveitis is still not very well understood. We investigated the proteome of the iris tissue harvested from healthy donor eyes that were enucleated within 6 h of death using high-resolution Fourier transform mass spectrometry. A total of 4959 nonredundant proteins were identified in the human iris, which included proteins involved in signaling, cell communication, metabolism, immune response, and transport. This study is the first attempt to comprehensively profile the global proteome of the human iris tissue and, thus, offers the potential to facilitate biomedical research into pathological diseases of the uvea such as Behcet's disease, Vogt Koyonagi Harada's disease, and juvenile rheumatoid arthritis. Finally, we make a call to the broader visual health and ophthalmology community that proteomics offers a veritable prospect to obtain a systems scale, functional, and dynamic picture of the eye tissue in health and disease. This knowledge is ultimately pertinent for precision medicine diagnostics and therapeutics innovation to address the pressing needs of the 21st century visual health.