Corneal Endothelial Alterations in Chronic Renal Failure

PURPOSE To evaluate the corneal endothelial changes in patients with chronic renal failure. METHODS A total of 128 corneas of 128 subjects were studied, and 3 groups were formed. The first, the dialyzed group, composed of 32 corneas of 32 patients; the second, the nondialyzed group, composed of 34 corneas of 34 patients; and the third, the age-matched control group, composed of 64 corneas of 64 healthy subjects were examined by a specular microscope and the endothelial parameters were compared. The dialyzed group (enhanced level of toxins in the blood) was further analyzed to assess the influence of blood urea, serum creatinine, serum calcium, and serum phosphorus including the duration of dialysis on corneal endothelium. RESULTS On comparing the 3 groups using analysis of variance and posthoc tests, a significant difference was found in the central corneal thickness (CCT) and endothelial cell density (CD) between the control (CCT: 506 ± 29 μm, CD: 2760 ± 304 cells/mm) and dialyzed groups (CCT: 549 ± 30 μm, CD: 2337 ± 324 cells/mm) [P < 0.001 (CCT); P < 0.001 (CD)]; control and nondialyzed groups (CCT: 524 ± 27 μm, CD: 2574 ± 260 cells/mm) [P = 0.023 (CCT); P = 0.016 (CD)]; and dialyzed and nondialyzed groups [P = 0.002 (CCT); P = 0.007 (CD)]. Using the linear generalized model, a significant correlation was found between the endothelial parameters and blood urea only [P = 0.006 (CCT), 0.002 (coefficient of variation), 0.022 (CD), and 0.026 (percentage of hexagonality)], although the correlation was poorly positive for CCT but poorly negative for the remaining endothelial parameters. CONCLUSIONS Corneal endothelial alteration is present in patients with chronic renal failure, more marked in patients undergoing hemodialysis and with raised blood urea level.