Simulating the effect of eye rubbing on corneal deformation using Finite Element Modelling
Tez Türü: Yüksek Lisans
Tezin Yürütüldüğü Kurum: University College London, Faculty of Engineering, Department of Mechanical Engineering, İngiltere
Tez Danışmanı: Ryo Torii
Tezin Onay Tarihi: 2021
Tezin Dili: İngilizce
Desteklendiği Program: Diğer
Özet:
Keratoconus is characterised by conical protrusion, significant steepening and thinning of the cornea. It causes a significant visual disturbance, with 12-20% of the patients eventually requiring corneal transplantation. Clinical research has shown a consistent relationship between the development and progression of keratoconus with habitual eye rubbing. However, not all healthy subjects who rub their eyes develop keratoconus, and only between 30 to 50% of keratoconus patients report habitual eye rubbing. This implies that categorising eye rubbing as a binary variable is unable to fully explain its relationship with keratoconus development, and there is more to other aspects of eye rubbing that warrant investigation. One potential aspect that requires further enquiry is the relationship between corneal geometry and the mechanical response induced by eye rubbing. Simulating eye rubbing in different corneal geometries has the potential to provide insight into which geometrical features are more predisposed to eye rubbing-related mechanical damage and hence keratoconus development. Although the best representation of the eye rubbing-induced mechanical response would be an in vivo experiment, this is technically and ethically not possible in human subjects. Hence, this project utilises Finite Element Analysis to simulate eye rubbing in patient-specific corneal models with various curvatures and thicknesses. Results suggest that stress and deformation responses are more pronounced in the steep cornea model. Corneal thinning also leads to an exaggerated mechanical response across the flat, normal and steep cornea models. Although a thicker cornea leads to diminished stress and deformation levels in flat and normal cornea models, maximum stress levels remain high in the steep cornea model. Further clinical research should validate whether a thinner and/or a steep cornea is associated with an increased clinical risk of keratoconus in patients who habitually rub their eyes.