Purpose: To compare small nerve fiber damage in the central cornea and whorl area in participants with diabetic peripheral neuropathy (DPN) and to examine the accuracy of evaluating these 2 anatomical sites for the diagnosis of DPN. Methods: A cohort of 187 participants (107 with type 1 diabetes and 80 controls) was enrolled. The neuropathy disability score (NDS) was used for the identification of DPN. The corneal nerve fiber length at the central cornea (CNFL center) and whorl (CNFL whorl) was quantified using corneal confocal microscopy and a fully automated morphometric technique and compared according to the DPN status. Receiver operating characteristic analyses were used to compare the accuracy of the 2 corneal locations for the diagnosis of DPN. Results: CNFL center and CNFL whorl were able to differentiate all 3 groups (diabetic participants with and without DPN and controls) (P < 0.001). There was a weak but significant linear relationship for CNFL center and CNFL whorl versus NDS (P < 0.001); however, the corneal location × NDS interaction was not statistically significant (P = 0.17). The area under the receiver operating characteristic curve was similar for CNFL center and CNFL whorl (0.76 and 0.77, respectively, P = 0.98). The sensitivity and specificity of the cutoff points were 0.9 and 0.5 for CNFL center and 0.8 and 0.6 for CNFL whorl. Conclusions: Small nerve fiber pathology is comparable at the central and whorl anatomical sites of the cornea. Quantification of CNFL from the corneal center is as accurate as CNFL quantification of the whorl area for the diagnosis of DPN.
Pritchard, N., Dehghani, C., Edwards, K., Burgin, E., Cheang, N., Kim, H., … Efron, N. (2015). Utility of assessing nerve morphology in central cornea versus whorl area for diagnosing diabetic peripheral neuropathy. Cornea, 34(7), 756–761. https://doi.org/10.1097/ICO.0000000000000447