Evaluation of optical coherence tomography findings and visual evoked potentials in Charcot-Marie-Tooth disease

Abstract Purpose: To evaluate the spectral-domain optical coherence tomography (SD-OCT) findings and pattern visual evoked potential (VEP) in Charcot-Marie-Tooth (CMT) disease.Methods: Seventeen patients with CMT disease and 17 control subjects were included in the study. The patients were divided into two groups according to conduction velocity and inheritance pattern as demyelinating type (CMT 1) and axonal type (CMT 2). The average retinal nerve fiber layer (RNFL) thickness, RNFL thicknesses of all quadrants, and thicknesses of the ganglion cell layer complex (GCC) were measured using SD-OCT. Pattern VEP recordings were evaluated in both groups.Results: The average and four quadrants of RNFL thicknesses, and superior and inferior GCC thicknesses were significantly thinner in the CMT patients compared with healthy individuals, but there were no statistically significant differences between the CMT groups. There was a significant positive correlation between age and all RNFL and GCC thicknesses in the CMT 2 group and between age and RNFL thickness of the temporal quadrant in the CMT 1 group. P100 latencies were significantly delayed in the CMT groups compared with controls and there were no significant differences in P100 latencies between the CMT groups (p<0.001). VEP amplitudes were in normal ranges in the CMT groups.Conclusion: This study showed that RNFL and GCC thicknesses were significantly reduced and VEP latencies were prolonged in patients with CMT with normal clinical examinations. Our results suggest that optic nerves may be affected more frequently in patients with CMT than is detected in clinical examinations.