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Citation
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Cheng Q, Zhang F, Chen Z, Wu L, Chen M, Xu Q, Wang Y. J. Craniofac. Surg. 2021; ePub(ePub): ePub. |
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Abstract
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PURPOSE: To evaluate the ciliary body mechanical load during low speed impact using finite element method to explain the mechanism of the cause of angle recession and cyclodialysis cleft.
METHODS: Optical coherence tomography images were obtained to assess the patient's ciliary body angle recession. A finite element eye model was established based on Virginia Tech eye model with the consideration of dynamic impact of a projectile striking an eye. The mechanical properties of the ocular tissues were obtained from literatures. The stress and strain were evaluated.
RESULTS: The stress distribution of the eye was calculated. The stress concentration at zonules was observed after 0.75 ms of the impact. The maximum stress at the cornea reached 3.8 MPa. The maximum stress at ciliary body was 57 KPa, which has high probability to cause ciliary body injury. The maximum stress at zonules was 0.98 MPa. The lateral expansion also reduces the forces transmitted along the sclera to the rear part of the eye.
CONCLUSIONS: The eye under frontal impact will result in lateral expansion, which increase the stretch force of the lens, zonules and ciliary body. This mechanism can be seen as the protection for retina. The boundary of ciliary body is the most vulnerable position, where angle recession and cyclodialyses cleft will occur before retina damage occurrence. TRANSLATIONAL RELEVANCE: The finite element model explains the blunt low speed impact induced ciliary body related injuries, which enables us to assess the ocular injury for low energy impact and better diagnosis and treatment in clinics.
Language: en |