[Affection on oxygen tension of the lens after vitrectomy]

To measure the oxygen tension (PO2) in the rabbit vitreous and lens and to investigate the mechanism by which it is controlled, the affection on oxygen tension of the lens after vitrectomy was studied.

Using a fiber-optic oxygen sensor system, oxygen tension of the rabbit vitreous and lens was probed in vivo and oxygen permeability of posterior capsule was also measured on isolated rabbit lens.

It was found that with agreement with previous study, PO2 is relatively high and the PO2 gradient is large in vitreous body close to the retina whereas more than 0.5 mm away from the retina the vitreal PO2 is relatively low and the PO2 gradient is very shallow. Oxygen tension in the lens is asymmetric with the anterior being higher than the posterior and oxygen in the posterior lens being at the similar tension as the anterior vitreous behind the lens. The posterior capsule of the rabbit lens is relatively high in oxygen permeability.

The vitreous body plays a key role in maintaining a low and stable level of oxygen in the lens. After vitrectomy oxygen tension in the lens may increase.