Corneal nerve morphology: a non-invasive surrogate of nerve fibre damage and repair in chemotherapy-associated peripheral neuropathy

摘要

Purpose: Chemotherapy-associated neuropathy is a cause of disability in patients with cancer, for diagnosis invasive techniques such as skin or sural nerve biopsy are used. Corneal confocal microscopy is a noninvasive technique that allows to assess a??in-vivoa?? all structures of the cornea, including the corneal nerves. The purpose of the current study is to determine the ability of this technique to quantify the degeneration and regeneration of corneal nerves in patients with peripheral neuropathy secondary to chemotherapy. Methods: Twelve patients with chemotherapy-associated neuropathy (study group) and 12 healthy volunteers were included. Laser in vivo confocal microscopy (IVCM) of the cornea was performed in one eye of each participant using the Heidelberg Retina Tomograph with the Rostock Cornea module. By a combination of clinical assessment and symptomatic neuropathy score an overall neuropathy score was obtained. Results: Median age was 59 year in the study group and 57.2 years in the control group. The average time between evaluation and completion of chemotherapy was 11,8 month (2-38 months). The severity of the neuropathy was mild in one patient (8.3%), moderate in 8 (66.6%) and severe in 3 patients (25%).The IVCM revealed a reduction in nerve density and number of branching in 7 patients (58.3%) compared with 1 (8.3%) in the control group (p=0.0272). There was not a significant correlation between the sub-basal nerve findings and the severity of the neuropathy and with the time of chemotherapy ending. Conclusions: Correlation between the chemotherapy-associated neuropathy and sub-basal nerve morphology has been found. Given that IVCM is a non invasive and painless technique which allows serial assessment of the sub-basal nerve morphology we suggest that IVCM may be an important tool to assess nerve degeneration and regeneration and therefore become a surrogate marker in the monitoring of chemotherapy associated neuropathy.