Corneal confocal microscopy detects small fiber damage in chronic inflammatory demyelinating polyneuropathy (CIDP)

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an autoimmune-mediated peripheral neuropathy with multifocal involvement. Reliable biomarkers for diagnosis, disease progression, and treatment response remain to be developed. We assessed the utility of corneal confocal microscopy (CCM) as a diagnostic marker for CIDP in 16 patients. CCM parameters including corneal nerve fiber density (NFD), nerve fiber length, number of main nerve trunks, number of nerve branches, nerve tortuosity, and dendritic cell density (DCD) were compared to those from 15 healthy controls and correlated with clinical and electrophysiological findings. CIDP patients had a significantly lower corneal NFD compared to healthy controls. The total nerve fiber length and the number of nerve branches were significantly decreased, whereas nerve tortuosity was increased in patients with CIDP. There was no positive correlation between corneal NFD and clinical or electrophysiological assessments. The average DCD was not significantly different in CIDP patients and controls. CCM measures suggest damage to small sensory afferents in the cornea in CIDP patients. Further studies are needed to compare different neuropathic conditions and to explore longitudinal changes of CCM parameters.