Ocular Surface - Merging Challenges and Opportunities.

Dichotomies are double-edged: they can simplify and enlighten as well as exaggerate and entangle. Seeing the eye as anterior segment vs. posterior segment simplifies the formidable task of dissecting the function of the eye. Yet this view creates artificial divisions in a coherent whole. Clearly, vision requires the convergence of the light refractive function of the front of the eye with the light sensing function of the back of the eye. The National Eye Institute has long aimed to foster research across the visual pathway. Finding the right balance is a constant work in progress. A recently held scientific meeting which we co-organized with the United States Army Medical Research Institute of Chemical Defense, offered an opportunity to take stock of what the anterior segment in general, and the ocular surface in particular, bring to our understanding of biology and disease of the eye. Multiple dichotomies surfaced: acute vs. chronic disease; epithelial vs. endothelial damage; fibrotic vs. vascular pathology; inflammation vs. resolution response; chemical exposure vs. countermeasure; monotherapy vs. combination therapy; mechanistic vs. exploratory research; human vs. animal model. Merging some of these dichotomies is the goal of this paper.