Corneal confocal sub‐basal nerve plexus evaluation: a review

Abstract

The aim of this study was to review the most recent data about corneal sub-basal nerve plexus (SNP) evaluated with the use of corneal confocal microscopy (CCM). For this purpose, an electronic search was conducted based on PubMed and Google Scholar and Web of Science databases from 2008 up to the end of 2016. Ninety-eight articles in English were cited, as well as abstracts in other languages, concerning the morphology and function of corneal SNP in various diseases. Changes in corneal SNP as a result of local treatment were also introduced. Figures with scans from confocal microscopy from our Department were included. The main conclusion of this review was that both corneal SNP diminishment and high tortuosity as well as low sensitivity are in principle related to the presence or level of pathology. In addition, increased nerve tortuosity may represent a morphological determinant of nerve regeneration. However, the presented literature shows that SNP changes are not characteristic for one unified corneal pathology; rather, they reflect the non-specific pathological process present in many diseases. Future studies should use automatized biometric software and also examine the effects of new treatments on SNP.

Impact of corneal parameters, refractive error and age on density and morphology of the subbasal nerve plexus fibers in healthy adults

“…Finally, we found, accordingly to other reports, that there were no differences between the left and right eye nor between genders in the IVCM parameters 2,3,[7][8][9][10][11][12][13]20,21,30,31 .…”

“…The SCCM and the LSCM are currently still in use, and both provide a high quality of nerve imaging 8 . However, to perform a comparative analysis of nerve characteristics in different groups, the same device must be used to avoid erroneous interpretation [1][2][3] . Nevertheless numerous studies on normal corneal SBNP nerves were conducted to the best of our knowledge there are no reports on the relation between SBNP morphology and density and corneal parameters and refraction in healthy eyes.…”

“…In the present study we found negative correlations between NFL, NFD and age. Some studies have shown no correlation between age and nerve density in healthy participants 3,29 . However, these studies were cross-sectional in their character.…”

Corneal confocal microscopy: ready for prime time

“…Based on the translational potential of CCM, in 2005, we proposed that quantification of the sub‐basal nerves using CCM may act as a surrogate marker of DPN . Since then, a burgeoning literature has irrefutably confirmed that CCM fulfils the Food and Drug Administration‐National Institutes of Health criteria as a biomarker for peripheral neuropathy . More recently, several studies have reported sub‐basal nerve alterations in central neurological disorders.…”

In vivo imaging of corneal nerves and cellular structures in mice with Gabor-domain optical coherence microscopy

“…Current options for in vivo corneal imaging include confocal microscopy and optical coherence tomography (OCT). Confocal microscopy has been used extensively to investigate the corneal nerves in vivo [21][22][23][24][25][26][27][28][29][30], and in the context of studying the changes induced with diabetes mellitus on corneal nerves in humans, mice and rats [19,[31][32][33][34][35][36]. Patients with diabetes had reduced densities of major corneal nerves and nerve branching, as well as increased tortuosity [31,32].…”