In vivo study of corneal responses to increased intraocular pressure loading.
In vivo study of corneal responses to increased intraocular pressure loading.
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DOI：
10.1186/s40662-015-0029-z
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发表时间：
2015
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影响因子：
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通讯作者：
Boneham GC
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作者：
Elsheikh A;McMonnies CW;Whitford C;Boneham GC
角膜负责眼睛屈光力的三分之二，屈光力是形状和折射率的函数。本研究的目的是检查在体人眼角膜形状的变化，以响应短期眼内压升高。将基线时的视频角膜照相和眼压测量评估与使用眼动力计压平巩膜将眼内压升高至约为基线水平两倍（199 ± 22%）时的相同评估进行比较。通过结合中央、鼻、颞、下和上级固定的地形评估，创建角膜和利姆布斯的复合图。为每个受试者定制数值有限元模拟，并修改角膜表面的刚度分布，以实现模拟数据和实验数据之间的匹配。实现模拟-实验匹配所需的刚度分布显示出与利姆布斯界定的2.5 mm环一致的趋势，与中央角膜相比，平均刚度降低47.3 ± 10.8%（P = 0.001）。与周边角膜相比，角膜结构似乎为中央角膜提供了更大的硬度，并对眼内压升高具有更大的耐受性，这与稳定的角膜屈光和视力的需求一致。采用的方法来检查角膜的生物力学性能在体内可能有其他研究中的应用。
The cornea is responsible for two-thirds of the eye's refractive power which is a function of the shape and refractive index. The aim of this present study is to examine human eyes in vivo for corneal shape changes in response to short-term elevation in intraocular pressure. Videokeratographic and tonometric assessments at baseline were compared with the same assessments when intraocular pressure was elevated to approximately double (199 ± 22 %) the baseline levels using ophthalmodynamometer applanation of the sclera. Composite maps of the cornea and limbus were created by combining topographical assessments for central, nasal, temporal, inferior and superior fixation. Numerical finite-element simulations were custom built for each subject and the stiffness distribution across corneal surface modified to achieve matches between simulated and experimental data. The stiffness distributions required to achieve simulation-experimental matches showed a consistent trend with the 2.5 mm annulus bounded by the limbus showing a mean stiffness reduction of 47.3 ± 10.8 % compared with the central cornea (P = 0.001). Corneal structure appears to provide the central cornea with a greater stiffness compared with the peripheral cornea and associated greater tolerance to elevation in intraocular pressure, consistent with the need for stable corneal refraction and vision. The method adopted to examine corneal biomechanical performance in vivo may have applications in additional studies.