Assessment of dynamic corneal nerve changes using static landmarks by in vivo large-area confocal microscopy-a longitudinal proof-of-concept study

Nadine Stache; Katharina A Sterenczak; Karsten Sperlich; Carl F Marfurt; Stephan Allgeier; Bernd Köhler; Ralf Mikut; Andreas Bartschat; Klaus-Martin Reichert; Rudolf F Guthoff; Angrit Stachs; Oliver Stachs; Sebastian Bohn

doi:10.21037/qims-22-15

Assessment of dynamic corneal nerve changes using static landmarks by in vivo large-area confocal microscopy-a longitudinal proof-of-concept study

Quant Imaging Med Surg. 2022 Oct;12(10):4734-4746. doi: 10.21037/qims-22-15.

Authors

Nadine Stache^#^{1

2}, Katharina A Sterenczak^#^{1

2}, Karsten Sperlich^{1

3}, Carl F Marfurt⁴, Stephan Allgeier⁵, Bernd Köhler⁵, Ralf Mikut⁵, Andreas Bartschat⁵, Klaus-Martin Reichert⁵, Rudolf F Guthoff^{1

3}, Angrit Stachs², Oliver Stachs^{1

3}, Sebastian Bohn^{1

3}

Affiliations

¹ Department of Ophthalmology, Rostock University Medical Center, Rostock, Germany.
² Department of Obstetrics and Gynecology, University of Rostock, Rostock, Germany.
³ Department Life, Light & Matter, University of Rostock, Rostock, Germany.
⁴ Department of Anatomy Cell Biology & Physiology, Indiana University School of Medicine-Northwest, Gary, USA.
⁵ Institute for Automation and Applied Informatics, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.

^# Contributed equally.

Abstract

Background: The purpose of the present proof-of-concept study was to use large-area in vivo confocal laser scanning microscopy (CLSM) mosaics to determine the migration rates of nerve branching points in the human corneal subbasal nerve plexus (SNP).

Methods: Three healthy individuals were examined roughly weekly over a total period of six weeks by large-area in vivo confocal microscopy of the central cornea. An in-house developed prototype system for guided eye movement with an acquisition time of 40 s was used to image and generate large-area mosaics of the SNP. Kobayashi-structures and nerve entry points (EPs) were used as fixed structures to enable precise mosaic registration over time. The migration rate of 10 prominent nerve fiber branching points per participant was tracked and quantified over the longitudinal period.

Results: Total investigation times of 10 minutes maximum per participant were used to generate mosaic images with an average size of 3.61 mm² (range: 3.18-4.42 mm²). Overall mean branching point migration rates of (46.4±14.3), (48.8±15.5), and (50.9±13.9) µm/week were found for the three participants with no statistically significant difference. Longitudinal analyses of nerve branching point migration over time revealed significant time-dependent changes in migration rate only in participant 3 between the last two measurements [(63.7±12.3) and (43.0±12.5) µm/week, P<0.01]. Considering individual branching point dynamics, significant differences in nerve migration rate from the mean were only found in a few exceptions.

Conclusions: The results of this proof-of-concept study have demonstrated the feasibility of using in vivo confocal microscopy to study the migration rates of corneal subbasal nerves within large areas of the central human cornea (>1 mm²). The ability to monitor dynamic changes in the SNP opens a window to future studies of corneal nerve health and regenerative capacity in a number of systemic and ocular diseases. Since corneal nerves are considered part of the peripheral nervous system, this technique could also offer an objective diagnostic tool and biomarker for disease- or treatment-induced neuropathic changes.

Keywords: Large-area in vivo confocal laser scanning microscopy mosaics; corneal subbasal nerve plexus (SNP); migration rate of corneal subbasal nerves.