Corneal Nerve Fractal Dimension: A Novel Corneal Nerve Metric for the Diagnosis of Diabetic Sensorimotor Polyneuropathy

Invest Ophthalmol Vis Sci. 2018 Feb 1;59(2):1113-1118. doi: 10.1167/iovs.17-23342.

Abstract

Objective: Corneal confocal microscopy (CCM), an in vivo ophthalmic imaging modality, is a noninvasive and objective imaging biomarker for identifying small nerve fiber damage. We have evaluated the diagnostic performance of previously established CCM parameters to a novel automated measure of corneal nerve complexity called the corneal nerve fiber fractal dimension (ACNFrD).

Methods: A total of 176 subjects (84 controls and 92 patients with type 1 diabetes) with and without diabetic sensorimotor polyneuropathy (DSPN) underwent CCM. Fractal dimension analysis was performed on CCM images using purpose-built corneal nerve analysis software, and compared with previously established manual and automated corneal nerve fiber measurements.

Results: Manual and automated subbasal corneal nerve fiber density (CNFD) (P < 0.0001), length (CNFL) (P < 0.0001), branch density (CNBD) (P < 0.05), and ACNFrD (P < 0.0001) were significantly reduced in patients with DSPN compared to patients without DSPN. The areas under the receiver operating characteristic curves for identifying DSPN were comparable: 0.77 for automated CNFD, 0.74 for automated CNFL, 0.69 for automated CNBD, and 0.74 for automated ACNFrD.

Conclusions: ACNFrD shows comparable diagnostic efficiency to identify diabetic patients with and without DSPN.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Cornea / innervation*
  • Diabetes Mellitus, Type 1 / diagnosis*
  • Diabetic Neuropathies / diagnosis*
  • Female
  • Fractals*
  • Humans
  • Male
  • Microscopy, Confocal
  • Middle Aged
  • Nerve Fibers / pathology*
  • Polyneuropathies / diagnosis*
  • ROC Curve
  • Trigeminal Nerve Diseases / diagnosis*