Ion movement in and out of the vitreous space after vitrectomy. An experimental study on the in vivo eyecup preparation of rabbits.

Osmotic pressure and ion movements in and out of the vitreous space after open-sky vitrectomy were studied in the in vivo eyecup of rabbits. The osmotic pressure of several hypo-osmotic solutions rose over a period of time by the penetration of ions from the surrounding tissue; increases in the concentration of sodium, chloride, potassium, and calcium were documented. Appearance and disappearance of ions were independent of the total osmolarity and depended on the concentration gradient for each ion.