Quantification of Collagen Ultrastructure after Penetrating Keratoplasty - Implications for Corneal Biomechanics

Boote, Craig ORCID: https://orcid.org/0000-0003-0348-6547, Dooley, Erin Patricia, Gardner, Steven, Kamma-Lorger, Christina S., Hayes, Sally ORCID: https://orcid.org/0000-0001-8550-0108, Nielsen, Kim, Hjortdal, Jesper, Sorensen, Thomas, Terrill, Nicholas J. and Meek, Keith Michael Andrew ORCID: https://orcid.org/0000-0002-9948-7538 2013. Quantification of Collagen Ultrastructure after Penetrating Keratoplasty - Implications for Corneal Biomechanics. PLoS ONE 8 (7) , e68166. 10.1371/journal.pone.0068166

Preview

PDF - Published Version Available under License Creative Commons Attribution. Download (8MB) | Preview

Abstract

Purpose: To quantify long-term changes in stromal collagen ultrastructure following penetrating keratoplasty (PK), and evaluate their possible implications for corneal biomechanics. Methods: A pair of 16 mm post-mortem corneo-scleral buttons was obtained from a patient receiving bilateral penetrating keratoplasty 12 (left)/28 (right) years previously. Small-angle x-ray scattering quantified collagen fibril spacing, diameter and spatial order at 0.5 mm or 0.25 mm intervals along linear scans across the graft margin. Corresponding control data was collected from two corneo-scleral buttons with no history of refractive surgery. Wide-angle x-ray scattering quantified collagen fibril orientation at 0.25 mm (horizontal)×0.25 mm (vertical) intervals across both PK specimens. Quantification of orientation changes in the graft margin were verified by equivalent analysis of data from a 13 year post-operative right PK specimen obtained from a second patient in a previous study, and comparison made with new and published data from normal corneas. Results: Marked changes to normal fibril alignment, in favour of tangentially oriented collagen, were observed around the entire graft margin in all PK specimens. The total number of meridional fibrils in the wound margin was observed to decrease by up to 40%, with the number of tangentially oriented fibrils increasing by up to 46%. As a result, in some locations the number of fibrils aligned parallel to the wound outnumbered those spanning it by up to five times. Localised increases in fibril spacing and diameter, with an accompanying reduction in matrix order, were also evident. Conclusions: Abnormal collagen fibril size and spatial order within the PK graft margin are indicative of incomplete stromal wound remodelling and the long term persistence of fibrotic scar tissue. Lasting changes in collagen fibril orientation in and around PK wounds may alter corneal biomechanics and compromise the integrity of the graft-host interface in the long term.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Optometry and Vision Sciences
Subjects:	R Medicine > RE Ophthalmology
Publisher:	PLoS
ISSN:	1932-6203
Funders:	MRC
Date of First Compliant Deposit:	30 March 2016
Last Modified:	10 Nov 2023 12:48
URI:	https://orca.cardiff.ac.uk/id/eprint/48618

Citation Data

Cited 13 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item