MECHANISM OF INTRAOCULAR-PRESSURE ELEVATION DURING HEMODIALYSIS

Pur-pose. To detect the mechanism of intraocular pressure elevation du ring hemodialysis. Methods. We measured intraocular pressure, as well as serum osmolality and plasma CO2 pressure, every 30 min during hemod ialysis, in 5 eyes with severely compromised aqueous outflow facility (Group A) from 4 renal failure patients. The same measurements were re peated on the same eyes using intravenous hyperosmotic Glyceol(R) to p revent a rapid change in serum osmolality. We also measured the same p arameters on 8 eyes with normal aqueous outflow facility (Group B) fro m 5 patients. The mean +/- SE of percent changes in each parameter was used for the statistical analysis Results. In Group A, the mean perce nt change of intraocular pressure increased significantly after 90 min , with the exception of the change at 180 min. The mean percent change of serum osmolality decreased significantly after starting dialysis. A negative correlation in the mean percent change of intraocular press ure with serum osmolality was detected (r = -0.759, r < 0.0001). The a dministration of intravenous hyperosmotic agent prevented significant changes in not only serum osmolality but also intraocular pressure. In Group B, the mean percent change in intraocular pressure showed no si gnificant difference at any time, although the change in serum osmolal ity decreased significantly. Conclusion. A remarkable rise in intraocu lar pressure occurs during hemodialysis in eyes with an impaired aqueo us outflow, when serum osmolality decreases rapidly.