Intraocular pressure changes during hemodialysis.

The response of intraocular pressure (IOP) to hemodialysis procedure has been a subject of research throughout many decades. Several studies that evaluated the impact of hemodialysis (HD) on IOP have reported conflicting results and have drawn varied conclusions. Some studies have described an IOP elevation during HD, a finding they attributed to the osmotic disequilibrium between serum and aqueous humor induced by the HD procedure, especially when the facility of the outflow system is already compromised. On the other hand, several studies have reported a significant IOP decrease during HD. The majority of these studies supported the notion that the increase in plasma colloid pressure induced by fluid removal during the HD session is the underlying cause of decreased IOP. Finally, recent investigations did not establish a significant change in IOP measurements during HD. They have therefore suggested that improved dialysis techniques, such as high-flux HD, or hemofiltration and better urea control, maintain better osmolar balance and prevent a marked IOP elevation. Nevertheless, specific preventive measures are still necessary in HD patients with ocular pathologies (e.g., glaucoma) whose vision may be adversely influenced by significant IOP fluctuation.