Effect of Intravenous Mannitol on Intraocular Pressure in Vitrectomized Silicone-Oil-Filled Eyes

To evaluate the effect of intravenous mannitol (IVM) on intraocular pressure (IOP) in vitrectomized eyes.

Thirty-one patients with raised IOP after retinal surgery with silicone oil injection were included. Patients were administered IVM (20% solution, 1g/Kg, over 30 minutes) and IOP was noted at regular intervals. IOP reduction in vitrectomized eyes (Group 1) was compared with the normal eyes (Group 2).

Percentage IOP reduction was higher in Group 1 than in Group 2 at all time intervals, 24.5% vs. 19.2% at 15 minutes (p=0.34), 22.6% vs. 9.8% at 45 minutes (p=0.003), 19.1% vs. 9.9% at two hours (p=0.023), and 16.1% vs. 7.8% at four hours (p=0.04), respectively. In Group 1, 40% eyes had an IOP reduction of 2-6 mmHg while 30% eyes had IOP reduction >6 mmHg at four hours post-IVM.

IVM is useful for short-term IOP reduction in vitrectomized eyes. IOP reduction is independent of baseline IOP, and sustained and higher as compared to normal eyes.