Pharmacologic vitreolysis

Abstract

Vitreous constitutes about 80 % of the volume of the human eye. It is an extended extracellular matrix that is composed of collagen, hyaluronan, and other extracellular matrix molecules but is 98 % water. In both health as well as disease, the molecular composition and organization of vitreous dictates the structure and function of the vitreous body as well as the status of the vitreoretinal interface. During aging, there is reorganization of vitreous macromolecules resulting in gel liquefaction and structural changes that destabilize the vitreous body. Molecular changes at the vitreoretinal interface, whose components are the retinal inner limiting membrane (ILM), the posterior vitreous cortex, and the intervening extracellular matrix (ECM), usually weaken vitreoretinal adhesion and allow the collapsing destabilized vitreous to separate from the retina, a condition called posterior vitreous detachment (PVD) [see chapter II.C. Vitreous aging and posterior vitreous detachment]. When there is insufficient weakening of vitreoretinal adherence, anomalous PVD occurs with various pathologic effects on both vitreous and retina [see chapter III.B. Anomalous PVD and vitreoschisis]. To date, these pathologies have been treated with surgery.