In Vivo Corneal Microstructural Changes in Herpetic Stromal Keratitis: A Spectral-Domain Optical Coherence Tomography Analysis

Abstract

Purpose: To describe and analyze the microstructural changes in herpetic stromal keratitis (HSK) observed in vivo by spectral-domain ocular coherence tomography (SD-OCT) at different stages of the disease.
 Methods: A prospective, cross-sectional, observational, and comparative SD-OCT analysis of corneas with active and inactive keratitis was performed, and the pathologic differences between the necrotizing and non-necrotizing forms of the disease were analyzed.
 Results: Fifty-three corneas belonging to 43 (81.1%) women and 10 (18.8%) men with a mean age of 41.0 years were included for analysis. Twenty-four (45.3%) eyes had active keratitis, and 29 (54.7%) had inactive keratitis; the majority (83.0%) had the non-necrotizing form. Most corneas (79.1%) with active keratitis showed stromal edema and inflammatory infiltrates. Almost half of the active lesions affected the visual axis, were found at mid-stromal depth, and had a medium density. By contrast, corneas with inactive keratitis were characterized by stromal scarring (89.6%), epithelial remodeling (72.4%), and stromal thinning (68.9%). In contrast to non-necrotizing corneas, those with necrotizing HSK showed severe stromal scarring, inflammatory infiltration, and thinning. Additionally, most necrotizing lesions (77.7%) affected the visual axis and had a higher density (P = 0.010).
 Conclusion: Active HSK is characterized by significant epithelial and stromal thickening and the inactive disease manifests epithelial remodeling at sites of stromal thinning due to scarring. Necrotizing keratitis is characterized by distorted corneal architecture, substantial stromal inflammatory infiltration, and thinning. In vivo SD-OCT analysis permitted a better understanding of the inflammatory and repair mechanisms occurring in this blinding corneal disease.

Stress–Strain Index Map: A New Way to Represent Corneal Material Stiffness

“…Assuming that the SSI regional variation follows the distribution of collagen fibrils is based on evidence establishing collagen fibrils as the main load-carrying components of corneal tissue, and hence being responsible for corneal stiffness ( Daxer et al, 1998 ; Bell et al, 2018 ). Relying on the link between microstructure and stiffness distribution was possible for five reasons; first, there is a considerable number of microstructure maps available for both healthy and keratoconic corneas ( Boote et al, 2006 ; Meek and Boote, 2009 ; Niederer and McGhee, 2010 ; Studer et al, 2010 ; Pijanka et al, 2013 ; Ho et al, 2014 ; Pandolfi et al, 2019 ; Zhou et al, 2019 ; Zvietcovich et al, 2019 ; Li et al, 2020 ; Rodriguez-Garcia et al, 2020 ). Second, there is a strong consistency in microstructure distribution in healthy corneas with little variation between individuals.…”

Anterior-segment optical coherence tomography for the detection and therapeutic monitoring of corneal disorders

“…Non-invasive procedure [1,4,15] Rapid image acquisition [4,5] Reproducible results [5,6] Comparable results [6] Safe procedure [1,5] Limited availability [14] Reduced brand diversity [4,5] Limited image resolution [2,16] Image distortion related to tissue refractive index [6] Need for high-trained personal [5] High sensitivity to movement [17]…”

“…Contrary to the traditional point of view proclaimed by certain corneal specialists that corneal pathology can Short communication be entirely assessed by direct slit-lamp visualization, arguing that imaging technology like AS-OCT is, in most cases, unnecessary and costly [4], recent investigators are demonstrating that AS-OCT has a place in examination of many ocular surface disorders [5]. In the last couple of years, AS-OCT imaging technology has been the subject for analyzing the microstructural changes of different inflammatory, infectious, degenerative, and dystrophic corneal disorders [5][6][7][8]. Many recent publications demonstrate the tendency to develop machine learning algorithms, efficient enough to help the clinician diagnose and detect disease activity and therapeutic monitoring of various corneal pathologies, including stromal edema associated with angle-closure glaucoma, Fuchs endothelial dystrophy, infectious keratitis, and bullous keratopathy [9,10].…”

“…There are particular instances where the aid of in-depth and en-face detailed tomographic images of the cornea are most helpful for diagnosing subtle recurrent epithelial and stromal edema in patients with active herpetic stromal keratitis (HSK) with significant scarring that hinder its direct slit-lamp visualization. Moreover, AS-OCT is very useful for analyzing extension of scar and leukoma depth for surgical planning of partial or total corneal transplantation [6,17,18].…”

Recent Advances in the Diagnosis and Management of Herpetic Keratitis

“…Active keratitis could be characterized Recent Advances in the Diagnosis and Management of Herpetic Keratitis DOI: http://dx.doi.org/10.5772/intechopen.96898 by the presence of the ulceration, stromal edema and inflammatory hyperreflective infiltrates. Corneas with inactive keratitis are characterized by stromal scarring and thinning, and epithelial remodeling [17][18][19][20][21][22]. Characteristic OCT features are presented in the Figure 7.…”