Chemokines: new insights in the treatment of glaucoma and inflammatory diseases of the ocular surface

The celebrations of the 200th anniversary of Claude Bernard's birth ( 1813) give us the opportunity to recall all the pioneer work carried out by the great physiologist, which still remains relevant in both scientific and medical fields. The description that tissues are "floating in a liquid milieu" bringing survival molecules and allowing homeostasis, is particularly illustrated in the physiopathology of glaucoma. Second leading cause of blindness worldwide, glaucoma is an optic neuropathy mainly related to an increase of intraocular pressure. Degeneration of the trabecular meshwork, the filter that allows aqueous humor outflow from the eye, includes loss of trabecular cells, extracellular matrix remodeling, oxidative stress, and release of inflammatory cytokines, which are together the hallmarks of glaucoma. Although globally efficient, the topical treatments of glaucoma with eye drops containing active compounds produce, in the long-term, side effects mainly due to benzalkonium chloride, a preservative added to prevent bottle contamination. Such compound induces inflammatory processes. Thus, new data involving chemokines such as CXCL12, known to play a key role in inflammation and cellular crosstalk in the trabecular meshwork, offer new targets for the development of innovative treatments in glaucoma.