The Analysis Of Cornea Refractive Surgery Based On The Finite Element Method

The construction of virtual organ is one of the frontier research areas. As one of the most important and tiny organs of human, eye should be modeled and simulated factitiously. Cornea—as one of the most important part of eye affects the refraction of the eye most. Corneal refractive surgery by changing the corneal refractive power to achieve the purpose of correcting refractive errors. It is welcomed among people because the surgery is convenient and the curative effect is remarkable. The doctor and patient are always concerned about the stress distribution before and after surgery and the effect of parameters' changes in the operation. In this paper, the finite element models were built respectively before and after refractive surgery with the finite element software ANSYS. The stress distribution of the cornea before and after surgery, the impact of intraocular pressure to the cornea was analyzed. This can predict for the different scenarios of actual surgery, and can provide practical guidance for the refractive surgery.In this thesis, the establishment of a number of corneal refractive surgery before and after the finite element model based on the simplified model of the cornea on the physical form of the cornea; and then in the establishment of the finite element model based on the current common of refractive surgery (RK, LTK, LASIK) simulation and analysis, to explore the realization of the principle of the refractive surgery, and a detailed analysis of intraocular pressure on the impact of corneal refractive surgery and the operation parameters on the corneal refractive surgery the impact of.Followings are the innovations of this thesis:1. The finite element models of cornea before and after the RK surgery were constructed, and simulated the corneal shape before and after the RK surgery. Then analyze the effects of intraocular pressure in normal circumstances and after RK surgery to the refractive surgery, and study the impact of the depth of the surgical incision to the surgery. 2. First of all, the corneal thermal analysis under the laser irradiation was carried out to examine the cornea after laser irradiation in the heat distribution and heat transfer situation based on the characteristics of the LTK surgery; And then on the basis of the establishment of post-operative LTK finite element model, comparative analysis the intraocular pressure in the same role in different optical zone radius of the impact of surgery on the LTK and the same under the different optical zone diameter of the intraocular pressure of the impact of corneal.3. The laser in situ keratomileusis (LASIK surgery) was simplified and analyzed. First the post-operative finite element model of the cornea was set up, and then a detailed analysis of the surgical cutting of the effect of thickness on the impact of surgery and intraocular pressure effects of surgery the impact of, and RK surgery and LASIK surgery for the treatment of myopia has done.