Corneal densitometry and anterior segment changes in patients undergoing maintenance hemodialysis

To evaluate corneal densitometry and anterior segment parameters in patients undergoing maintenance hemodialysis compared with healthy controls, and to assess acute changes following a single hemodialysis session.

This prospective controlled observational study included 66 eyes of 66 subjects: 30 patients undergoing maintenance hemodialysis and 36 age-matched healthy controls. Anterior segment imaging was performed using a rotating Scheimpflug camera (Pentacam HR). Corneal densitometry values were analyzed across predefined corneal layers and annular zones. In the hemodialysis group, measurements were obtained immediately before and 1 h after dialysis, enabling both between-group (controls vs pre-dialysis) and within-group (pre- vs post-dialysis) comparisons. Anterior segment and pachymetric parameters were also recorded.

The primary outcome, total corneal densitometry in the central 0-2 mm zone, was significantly higher in patients undergoing maintenance hemodialysis than in healthy controls (16.65 ± 1.18 vs 15.92 ± 1.30 GSU; mean difference: 0.73 GSU; 95% CI: 0.12-1.34; FDR-adjusted p = 0.027). Additional increases were observed across posterior and peripheral corneal regions, with the largest mean difference observed in the total 10-12 mm zone. Following hemodialysis, densitometry increased further, most prominently in the anterior 0-2 mm zone (20.82 ± 1.51 vs 22.31 ± 1.69; FDR-adjusted p < 0.001). Additional differences were observed in anterior segment and pachymetric parameters both between groups and after dialysis.

Patients undergoing maintenance hemodialysis demonstrate increased corneal light scatter compared with healthy controls, along with additional acute changes following a dialysis session. Corneal measurements should therefore be interpreted in relation to the timing of dialysis.