Changes in the Choroidal Thickness and Axial Length Upon Mannitol Infusion in Patients With Asymmetric Intraocular...

To evaluate the changes in the choroidal thickness (CT) and axial length (AL) upon systemic mannitol infusion in glaucoma patients with asymmetric intraocular pressure (IOP).

Forty glaucoma patients with asymmetric IOP, with the IOP of 1 eye ≥40 mm Hg and the fellow eye <25 mm Hg, were administered 150 mL of a 20% mannitol infusion to reduce the IOP. The CT and AL were measured before and an hour after the infusion. The relationship between the IOP reduction and the changes in the CT and AL were investigated.

The mean decrease in the IOP was -14.23 mm Hg (32.15%) and -4.13 mm Hg (21.40%) in the eyes with higher IOP and their fellow eyes, respectively. The mean changes in the subfoveal CT were 19.28 µm (9.20%; P<0.001) and 2.60 µm (1.93%; P=0.452) in the eyes with higher IOP and their fellow eyes, respectively. The mean changes in the AL were -0.10 µm (0.42%; P<0.001) and -0.33 mm (0.14%; P=0.008) in the eyes with higher IOP and their fellow eyes, respectively. Stepwise analysis revealed that the percent IOP change is the most influential factor on the percent change of the subfoveal CT (P<0.0001; R=0.3).

These results suggest that large IOP changes upon mannitol infusion cause the shortening of the AL in both the eyes and the thickening of the choroid only in the eyes with a higher IOP.