The three-dimensional(3D)mechanical response of the cornea to intraocular pressure(IOP)elevation has not been previously reported.In this study,we use an ultrasound speckle tracking technique to measure the 3D displac...The three-dimensional(3D)mechanical response of the cornea to intraocular pressure(IOP)elevation has not been previously reported.In this study,we use an ultrasound speckle tracking technique to measure the 3D displacements and strains within the central 5.5 mm of porcine corneas during the whole globe infation.Infation tests were performed on dextran-treated corneas(treated with a 10%dextran solution)and untreated corneas.The dextran-treated corneas showed an inflation response expectod of a thin spherical shell,with through-thickness thinning and in-plane stretch,although the strain magnitudes exhibited a heterogeneous spatial distribution from the central to more peripheral cornea.The untreated eyes demon-strated a response consistent with swelling during experimentation,w ith through-thickness expansion overriding the infation response.The average volume ratios obtained in both groups was near 1 confirming general incompresibility,but local regions of volume loss or expansion were observed.These results suggest that biomechanical measurements in 3D provide important new insight to understand the mechanical response of ocular tissues such as the cornea.展开更多
基金funded by NIH/NEI Grants R01EY020929 and R01EY025358.
文摘The three-dimensional(3D)mechanical response of the cornea to intraocular pressure(IOP)elevation has not been previously reported.In this study,we use an ultrasound speckle tracking technique to measure the 3D displacements and strains within the central 5.5 mm of porcine corneas during the whole globe infation.Infation tests were performed on dextran-treated corneas(treated with a 10%dextran solution)and untreated corneas.The dextran-treated corneas showed an inflation response expectod of a thin spherical shell,with through-thickness thinning and in-plane stretch,although the strain magnitudes exhibited a heterogeneous spatial distribution from the central to more peripheral cornea.The untreated eyes demon-strated a response consistent with swelling during experimentation,w ith through-thickness expansion overriding the infation response.The average volume ratios obtained in both groups was near 1 confirming general incompresibility,but local regions of volume loss or expansion were observed.These results suggest that biomechanical measurements in 3D provide important new insight to understand the mechanical response of ocular tissues such as the cornea.
