Peripheral neuropathy in Parkinson disease: An in vivo confocal microscopy study

Abstract

AbstractPurpose To assess whether corneal confocal microscopy (CCM) can detect alterations in corneal nerve morphology in patients with Parkinson disease.Methods Twenty‐five patients with Parkinson disease and 25 control subjects were examined. Patients underwent neurological and complete ophthalmological evaluation. Corneal sensitivity testing was performed with a Cochet‐Bonnet esthesiometer and corneal sub‐basal nerve morphology assessment with confocal microscopy (Heidelberg Retina Tomograph II/Rostock Cornea Module). CCM was used to quantify corneal nerve fibre density, tortuosity, length and branch density.Results Patients with Parkinson disease had decreased corneal sensation in comparison with controls. Corneal nerve fiber morphology differed in both groups, with a lower global fiber density, branch density and higher tortuosity in Parksinson patients (p<0,05). These parameters were found to be related to dopaminergic medication exposure.Conclusion We found a decreased corneal sensation and corneal nerve fiber changes in patients with Parkinson disease. CCM may be used to detect signs of peripheral neuropathy and follow patients in dopaminergic therapy.