Journal article
Posterior Embryotoxon Revisited: An Immunohistologic Study
Ophthalmology. Glaucoma, Vol.5(4), pp.396-401
07/2022
DOI: 10.1016/j.ogla.2022.01.003
PMID: 35131519
Abstract
To describe the histologic and immunohistochemical characteristics of posterior embryotoxon (PE) in patients with and without ocular or systemic anomalies.
Case series
Archived specimens from patients with PE
Sections from archived formalin-fixed paraffin-embedded specimens (n=9, 7 autopsy and 2 trabeculectomy specimens) were examined by light microscopy. Immunohistochemistry was performed on 5 specimens to characterize the extracellular matrix composition of PE.
Posterior embryotoxon appeared as nubs of whorled collagen extending from the corneal stroma, lined in some instances, by Descemet membrane. These nubs were located anterior to Schwalbe line (n=4), posteriorly (n=1), partially embedded in the trabecular meshwork (n=1) or at Schwalbe line (n=2). Qualitatively, collagen I labeling of the PE stroma was similar or weaker than the corneal stroma, whereas collagen III staining was focal and slightly more intense compared to the corneal stroma. Lumican and keratan sulfate staining was similar or less intense in PE compared to the corneal stroma.
Identify location of PE and its immunohistochemical features
In contrast to the widely accepted definition of PE as a prominent, anteriorly displaced Schwalbe line, histological evidence suggests that it is a direct extension of the corneal stroma with variable locations that may displace the attenuated Descemet membrane when located anterior to or at Schwalbe line. Immunohistochemical examination revealed that the composition of PE’s extracellular matrix was similar to corneal stroma but with some variability in staining intensity.
This series describes the immunopathologic features of posterior embryotoxon and demonstrates that it is not anterior displaced Schwalbe’s line as commonly described, but a peripheral corneal stromal nub variable in location with abnormal extracellular matrix.
Details
- Title: Subtitle
- Posterior Embryotoxon Revisited: An Immunohistologic Study
- Creators
- Saeed Alwadani - King Khaled Eye Specialist Hospital, Riyadh, Saudi ArabiaWallace L.M Alward - Department of Ophthalmology and Visual Sciences and, University of Iowa Carver College of Medicine, Iowa City, IowaNasreen A Syed - Department of Ophthalmology and Visual Sciences and, University of Iowa Carver College of Medicine, Iowa City, IowaRachida A Bouhenni - Vision Center, Akron Children’s Hospital, Akron OHSeymour Brownstein - Departments of Ophthalmology and of Pathology, Faculty of Medicine, University of Ottawa and The Ottawa Hospital, Ottawa, Ontario, CanadaDeepak P Edward - King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
- Resource Type
- Journal article
- Publication Details
- Ophthalmology. Glaucoma, Vol.5(4), pp.396-401
- DOI
- 10.1016/j.ogla.2022.01.003
- PMID
- 35131519
- NLM abbreviation
- Ophthalmol Glaucoma
- ISSN
- 2589-4196
- eISSN
- 2589-4196
- Publisher
- Elsevier Inc
- Language
- English
- Electronic publication date
- 02/04/2022
- Date published
- 07/2022
- Academic Unit
- Pathology; Ophthalmology and Visual Sciences
- Record Identifier
- 9984215029902771
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