IV.B. Oxygen in Vitreoretinal Physiology and Pathology

As recently as two decades ago, textbooks on vitreous taught students of ophthalmology that the vitreous gel had no real function in the adult eye other than to serve as a space-occupying, optically clear structure. In fact, one such textbook published in 1994 stated, “Apart from its role in oculogenesis, the vitreous has no well substantiated function so that an eye devoid of gel is not adversely affected” [1]. However, beginning in 2005 with published reports of oxygen tension measurements in the human vitreous gel before and after vitrectomy surgery [2] and culminating with reports in 2009 that the human vitreous gel consumes oxygen in an ascorbate-dependent manner [3], a new understanding of the vitreous gel and its role in vitreoretinal physiology and pathology has emerged.