Changes in Intraocular Pressure During Hemodialysis: A Meta-analysis

Precis: Acetate dialysate causes elevation of intradialytic intraocular pressure (IOP) and contributed to the rise of IOP in the early years of hemodialysis (HD). Glaucoma, narrow-angle, or impaired aqueous outflow is another moderator causing a rise of intradialytic IOP. Purpose: Severe IOP elevation during HD has been described in many case reports. However, the results of primary studies are conflicting. This meta-analysis examined the impact of HD on IOP and explored the potential moderators. Methods: Medline, PubMed, Embase, Web of Science, and Cochrane were systematically searched. Before-after studies reporting the change of IOP during HD were included. Intradialytic IOP changes were calculated based on 4 different definitions: highest-baseline, lowest-baseline, max-baseline, and end-baseline IOP difference. Standardized mean difference (SMD) was pooled using the random-effects model. Results: Fifty-three studies involving 1903 participants and 2845 eyes were included. Overall data pooling showed no significant rise in intradialytic IOP. However, subgroup analysis showed an intradialytic IOP rise before 1986 (SMD: 0.593; 95% confidence interval: 0.169-1.018; max-baseline IOP difference as representative; most studies using acetate dialysate), no change between 1986 and 2005 (using both acetate and bicarbonate), and a decline after 2005 (SMD: -0.222; 95% confidence interval: -0.382 to -0.063; entirely using bicarbonate). Multivariable meta-regression showed only the type of dialysate, but not publication year or other potential factors, as a significant moderator. Glaucoma was found to be another significant moderator independent of the dialysate effect in bivariate meta-regression. Conclusions: IOP elevation in the early years of HD with the use of acetate dialysate is less of a clinical problem following its substitution with bicarbonate dialysate. However, physicians should still be cautious of potential IOP changes in the HD population with glaucoma.