retinal never fiber layer thickness in chronic renal failure: analysis by optical coherence tomography

Purpose: To analyze the retinal nerve fiber layer thickness (RNFL) in CKD patients by means of optical coherence tomography, ascertaining mean overall RNFL and mean RNFL in the nasal, temporal, superior, and inferior quadrants and comparing these measurements to those obtained from a control group. Methods: This was a prospective, analytical, cross-sectional case-control study. The study sample comprised 22 eyes from 11 patients and 33 eyes from 17 patients in the case and control groups respectively. RNFLT was measured with a model 3000 OCT unit (Stratus OCT-3â„¢, Carl Zeiss Meditec Inc., Dublin, CA). The fast RNFL protocol was used, which consists of three consecutive 3.4-mm-diameter circular scans centered on the optic nerve. Measured parameters included overall mean RNFL and mean RNFL at the temporal (316–45°), superior (46–135°), nasal (136–225°), and inferior (226–315°) quadrants. The Mann-Whitney U was employed to assess possible between-group differences in mean overall RNFL and RNFL at the superior, temporal, nasal, and inferior quadrants. The null hypothesis was rejected when p-values were smaller than the set significance level of <0.05. Results: Mean RNFL overall and at the superior, nasal, and inferior quadrants was greater in the control group, and that no significant between-group differences were detected in RNFL at the temporal quadrant. Conclusion: Mean retinal nerve fiber thickness was significantly lower in the group of patients with CRF than in the control group. Ischemia resulting from uremia may explain the overestimation of cases of glaucomatous optic neuropathy.   Keywords: Chronic Kidney Failure, Uremia, Optical Coherence Tomography, Retina