Quantifying the effects of hydration on corneal stiffness with noncontact optical coherence elastography.

ABSTRACT: PURPOSE:To quantify the effects of the hydration state on the Young's modulus of the cornea. SETTING:Biomedical Optics Laboratory, University of Houston, Houston, Texas, USA. DESIGN:Experimental study. METHODS:Noncontact, dynamic optical coherence elastography (OCE) measurements were taken of in situ rabbit corneas in the whole eye-globe configuration (n = 10) and at an artificially controlled intraocular pressure of 15 mm Hg. Baseline OCE measurements were taken by topically hydrating the corneas with saline for 1 hour. The corneas were then dehydrated topically with a 20% dextran solution for another hour, and the OCE measurements were repeated. A finite element method was used to quantify the Young's modulus of the corneas based on the OCE measurements. RESULTS:The thickness of the corneas shrank considerably after topical addition of the 20% dextran solution (?680 ?m to ?370 ?m), and the OCE-measured elastic-wave speed correspondingly decreased (?3.2 m/s to ?2.6 m/s). The finite element method results showed an increase in Young's modulus (500 kPa to 800 kPa) resulting from dehydration and subsequent thinning. CONCLUSION:Young's modulus increased significantly as the corneas dehydrated and thinned, showing that corneal geometry and hydration state are critical factors for accurately quantifying corneal biomechanical properties.

SUBMITTER: Singh M 

PROVIDER: S-EPMC6097919 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature