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Matthew R. Ford, Abhijit Sinha Roy, Andrew M. Rollins, William J. Dupps, Jr.; Oct Based Elastography Of The Human Cornea In Edematous, Normal, And Crosslinked States. Invest. Ophthalmol. Vis. Sci. 2011;52(14):4197.
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© ARVO (1962-2015); The Authors (2016-present)
To compare spatial corneal biomechanical behavior in three different tissue states--edematous, normal and crosslinked--with an Optical Coherence Tomography (OCT)-based elastography system.
Five pairs of human donor globes were mounted serially beneath a custom SD-OCT anterior segment imaging device. A gonioscopy lens applied a compressive force at the corneal surface. Images from the central 4mm of the cornea were then processed using a cross correlation algorithm which tracks corneal displacement. The donor pairs were measured after pressurization (edematous), after thinning, and after a clinical riboflavin/UV crosslinking protocol was employed. Lateral displacement measurements were made and expressed as a fraction of the imposed axial compressions and fit to a line. The slope of the line was then used in an ANOVA based statistical analysis to determine the impact of edema , deturgescence and crosslinking on the properties of the cornea across 8 regions of the central cornea.
The donor eyes showed no statistically significant differences between left and right eyes, the 8 central corneal regions, or the two meridia measured. Statistically significant differences were observed between the three states (edematous, normal, and post crosslinking) with mean values of 0.037 um/um, 0.021 um/um and 0.017 um/um, respectively (p <0.05 by Tukey analysis)
Significant differences in lateral displacement responses were noted between edematous, normal and cross-linked corneas under clinically feasible stress conditions. These data suggest that crosslinking confers resistance to lateral strain in the cornea and may account for its effectiveness in the treatment of keratoconus, a disease proposed to be associated with lamellar slippage. While statistically significant differences in regional properties were not established, location-dependent variation was evident within individual eyes.
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