Purpose:To evaluate the effect of erythropoietin (EPO) treatment on retinal nerve fiber layer (RNFL) parameters in patients with chronic renal failure (CRF) undergoing peritoneal dialysis (PD).Methods:Fifty-eight eyes of 29 patients with CRF undergoing PD were evaluated. Fifteen patients have been treated with EPO (group 1), 14 patients without EPO treatment (group 2), and 30 eyes of 15 age-matched normal control subjects were assessed in group 3. A complete ophthalmologic examination and RNFL measurements were performed for each patient after PD. Anemia parameters were also measured. RNFL thickness protocol was used to acquire circular scans of 3.4 mm in diameter around optic nerve. RNFL thicknesses were evaluated in 4 quadrants. Only the left eyes were recruited for statistical analysis. The mean and quadrantal RNFL thickness values in group 1 were compared with those of groups 2 and 3.Results:The mean RNFL thickness values in patients undergoing PD were statistically lower than the control group at superior, inferior, nasal, and temporal quadrant, respectively (P=0.03, 0.04, 0.04, and 0.03). Differences between the RNFL thickness values in group 1 and group 2 were statistically significant only in the temporal quadrant (P=0.02).Conclusions:In patients with CRF undergoing PD, RNFL thickness parameters were found to be significantly reduced. The effect of EPO on RNFL parameters was statistically significant only in the temporal quadrant.