Quantifying the effects of hydration on corneal stiffness with noncontact optical coherence elastography. Issue 8 (August 2018)

• Record Type: Journal Article
• Authors: Singh, Manmohan; Han, Zhaolong; Li, Jiasong; Vantipalli, Srilatha; Aglyamov, Salavat R.; Twa, Michael D.; Larin, Kirill V.
• Is Part Of: Journal of cataract and refractive surgery. Volume 44:Issue 8(2018)
• Publication Date: 2018-08
• Subjects: 617.7
• DOI: 10.1016/j.jcrs.2018.03.036
• Languages: English
• ISSNs: 0886-3350

Abstract

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 μm to ˜370 μm), 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.