Corneal biomechanics: a review

Abstract

Biomechanics is often defined as ‘mechanics applied to biology’. Due to the variety and complexity of the behaviour of biological structures and materials, biomechanics is better defined as the development, extension and application of mechanics for a better understanding of physiology and physiopathology and consequently for a better diagnosis and treatment of disease and injury. Different methods for the characterisation of corneal biomechanics are reviewed in detail, including those that are currently commercially available (Ocular Response Analyzer and CorVis ST). The clinical applicability of the parameters provided by these devices are discussed, especially in the fields of glaucoma, detection of ectatic disorders and orthokeratology. Likewise, other methods are also reviewed, such as Brillouin microscopy or dynamic optical coherence tomography and others with potential application to clinical practice but not validated for in vivo measurements, such as ultrasonic elastography. Advantages and disadvantages of all these techniques are described. Finally, the concept of biomechanical modelling is revised as well as the requirements for developing biomechanical models, with special emphasis on finite element modelling.

Simulation of Air Puff Tonometry Test Using Arbitrary Lagrangian-Eulerian (ALE) Deforming Mesh for Corneal Material Characterisation

“…Moreover, this test was proven to have a promising potential in corneal material characterisation and Keratoconus detection [12]- [15].Tonometry is based on a simple concept of applying a known load causing deformation in the cornea and relating this load to the pressure inside the eye. However, accuracy of intraocular pressure (IOP) estimation continues to be a challenge due to the effect of corneal parameters including corneal geometry and material properties [16], [17]. The interplay between corneal geometry, material properties, ocular fluids and the air puff was studied before theoretically, numerically and clinically but with assumptions for the fluid structure interaction effect.…”

Effects of ablation depth and repair time on the corneal elastic modulus after laser in situ keratomileusis

“…The central corneal thickness and curvature change in this surgical procedure, and the cornea undergo tissue remodeling after injury, resulting in the alteration of the corneal biomechanical properties [1]. To perform refractive surgery more accurately, it has been proposed that the biomechanical properties of the cornea should be taken into account [2]. Moreover, post-LASIK keratectasia, a rare but severe complication occurs when a surgical procedure is performed with increasing frequency [3].…”

Assessment of corneal properties based on statistical modeling of OCT speckle

“…Alterations of the corneal shape and structure may affect not only its optical properties but also contribute to changes in its biomechanical properties [3]. Changes to corneal tissue may have pathological origin as in the case of keratoconus [4] or be a result of corneal surgery [5,6], which is nowadays commonly used to compensate refractive errors.…”