Vitrectomy, lensectomy, and ocular oxygenation.

The effect of vitrectomy and lensectomy upon the anterior chamber oxygen tension of the cat eye was measured polarographically. After vitrectomy and lensectomy alone, a reduction of 12 mm Hg (35%) was observed and when retinal veins were also partially occluded, a reduction of 17 mm Hg (50%) was measured as compared with the normal oxygen tension (PO2) of 34 mm Hg. If vitrectomy and lensectomy allow aqueous to deliver oxygen from the anterior part of the eye to the retina, the poorer oxygenation of the iris and the improved oxygenation of the retina might explain both the development of rubeosis iridis and stabilization of proliferative diabetic retinopathy so commonly seen following vitrectomy.