Laser Scanning In Vivo Confocal Microscopy Demonstrating Significant Alteration of Human Corneal Nerves Following Herpes Zoster Ophthalmicus

Purpose.To evaluate the changes of keratocytes and dendritic cells in the central clear graft by laser scanning in vivo confocal microscopy after penetrating keratoplasty (PK).Methods.Thirty adult subjects receiving PK at Shandong Eye Institute and with clear grafts and no sign of immune rejection after surgery were recruited into this study, and 10 healthy adults were controls. The keratocytes and dendritic cells in the central graft were evaluated by laser scanning confocal microscopy, as well as epithelium cells, keratocytes, corneal endothelium cells, and corneal nerves (especially subepithelial plexus nerves).Results.Median density of subepithelial plexus nerves, keratocyte density in each layer of the stroma, and density of corneal endothelium cells were all lower in clear grafts than in controls. The dendritic cells of five (16.7%) patients were active in Bowman’s membrane and stromal membrane of the graft after PK.Conclusions.Activated dendritic cells and Langerhans cells could be detected in some of the clear grafts, which indicated that the subclinical stress of immune reaction took part in the chronic injury of the clear graft after PK, even when there was no clinical rejection episode.

Download Full-text

Identification of presumed corneal neuromas and microneuromas using laser-scanning in vivo confocal microscopy: a systematic review

British Journal of Ophthalmology ◽

10.1136/bjophthalmol-2020-318156 ◽

2021 ◽

pp. bjophthalmol-2020-318156

Author(s):

Holly Rose Chinnery ◽

Rajni Rajan ◽

Haihan Jiao ◽

Mengliang Wu ◽

Alexis Ceecee Zhang ◽

...

Keyword(s):

Systematic Review ◽

Confocal Microscopy ◽

Laser Scanning ◽

Cochrane Library ◽

Human Cornea ◽

In Vivo Confocal Microscopy ◽

Ovid Medline ◽

Corneal Nerves ◽

Corneal Nerve

Background/aimsThis systematic review critically evaluated peer-reviewed publications describing morphological features consistent with, or using terms related to, a ‘neuroma’ or ‘microneuroma’ in the human cornea using laser-scanning in vivo confocal microscopy (IVCM).MethodsThe review was prospectively registered on PROSPERO (CRD42020160038). Comprehensive literature searches were performed in Ovid MEDLINE, Ovid Embase and the Cochrane Library in November 2019. The review included primary research studies and reviews that described laser-scanning IVCM for examining human corneal nerves. Papers had to include at least one of a pre-specified set of keyword stems, broadly related to neuromas and microneuromas, to describe a corneal nerve feature.ResultsTwenty-five papers (20 original studies; 5 reviews) were eligible. Three original studies evaluated corneal nerve features in healthy eyes. Most papers assessed corneal nerves in ocular and systemic conditions; seven studies did not include a control/comparator group. There was overlap in terminology used to describe nerve features in healthy and diseased corneas (eg, bulb-like/bulbous, penetration, end/s/ing). Inspection of IVCM images within the papers revealed that features termed ‘neuromas’ and ‘microneuromas’ could potentially be physiological corneal stromal-epithelial nerve penetration sites. We identified inconsistent definitions for terms, and limitations in IVCM image acquisition, sampling and/or reporting that may introduce bias and lead to inaccurate representation of physiological nerve characteristics as pathological.ConclusionThese findings identify a need for consistent nomenclature and definitions, and rigorous IVCM scanning and analysis protocols to clarify the prevalence of physiological, as opposed to pathological, corneal nerve features.

Download Full-text