Factors Influencing Intraocular Pressure Elevation During Hemodialysis

Purpose: The purpose of this study was to investigate intraocular pressure (IOP) and mean ocular perfusion pressure (MOPP) fluctuations during hemodialysis (HD) and identify clinical and HD-related factors associated with IOP elevation. Methods: This prospective, observational, single-center study included 103 eyes of 56 patients undergoing maintenance HD. IOP was measured at 5 time points: pre-dialysis (T0), 1 hour (T1), 2 hours (T2), 4 hours (T4), and 30 minutes post-dialysis (TP). MOPP was calculated at T0 to T4. Baseline laboratory data, including serum osmolality (PreOsm), were collected. Generalized estimating equation models evaluated the effects of time, lens status, and osmolality on IOP. Receiver operating characteristic (ROC) analysis was used to identify a PreOsm threshold for predicting IOP elevation >5 millimeters of mercury (mm Hg). Results: IOP increased during HD, peaking at 4 hours (17.5 ± 0.5 mm Hg) and returning to baseline at TP (14.6 ± 0.4 mm Hg, P < 0.001). MOPP declined over time. Phakic eyes showed significantly greater IOP at 1 and 2 hours compared with pseudophakic eyes (P = 0.022 and 0.048, respectively). Patients with PreOsm >312 milliosmolar (mOsm)/kg had greater IOP increases and were more likely to exhibit IOPrise >5 mm Hg in univariate and multivariate analyses (odds ratio [OR] = 3.94, 95% confidence interval [CI] = 1.21-12.79, P = 0.022 and OR = 3.38, 95% CI = 1.01-11.3, P = 0.048, respectively). Phakic lens status was associated with IOP elevation in univariate analysis (OR = 2.38, 95% CI = 1.01-5.56, P = 0.049), but in multivariate analysis, there was only a trend (P = 0.072). Conclusions: Transient intra-dialytic IOP elevation may be influenced by osmolality more so than lens status. Translational Relevance: These findings support the concept of ocular disequilibrium during HD and highlight the need for targeted ophthalmic monitoring in high-risk patients.