Changes in Intraocular Pressure during Hemodialysis.

This study was designed to determine the changes in intraocular pressure (10?) during hemodialysis in the uremic animal and to elucidate those parameters responsible for these changes. An increase in intraocular pressure averaging 41.8 per cent of the control occurred in uremic animals during dialysis. The rise started 21 minutes after dialysis was initiated and reached the maximum 45 to 75 minutes later. Changes in pCOt produced a significant increase in IOP. When the pCO2 was constant, changes in pH did not affect IOP. Experimental changes in body water demonstrated that dehydration was associated with a reduction in IOP; overhydration resulted in a significant increase in IOP. When hyperosmolality without weight change was induced by adding solute to the bath solution there was a significant decrease in IOP. Hypoosmolality induced by lowering solute concentration of the bath solution caused a significant rise in IOP. Thus, changes in pCOt, body toater content, and plasma osmolality which can occur during dialysis may all contribute to changes in IOP. Slow dialysis, removal of up to 2.6 per cent of the body weight in fluid, and prior administration of acetazolamide could prevent a rise in IOP in uremic dogs undergoing hemodialysis. Furthermore, there was no rise in IOP when the drop in osmolality was prevented through addition of appropriate concentrations of urea to the bath solution.