Figure 5.

Ciliary body stress. A, Internal elements of the ciliary body were measured for stress upon shuttlecock impact. The ciliary body undergoes an initial compressive stress up to nearly 0.39 MPa (point B for panel B visual), followed by building tensile stress of up to nearly 2 MPa (point C for panel C visual). Gradually, stress dissipates as it also oscillates in tensile amplitude or strength. Panels B to G display the IOP distribution at different time points indicated on the ciliary body stress plot. B, Initial impact induces a peak IOP of 5.66 MPa in the anterior chamber that distributes through the aqueous humor, inducing compressive stress on the ciliary body. The resulting lens displacement transfer compressive forces to the vitreous humor. C, The IOP distributed radially in the aqueous and vitreous humors induce tensile stress upon the ciliary body. D, The lens rebounds anteriorly causing a rise in IOP in the anterior chamber. Stress is temporarily alleviated in the ciliary body, as the direction of pressures from the aqueous and vitreous humors negate each other. E, Scleral buckling is more apparent and tensile stresses on the ciliary body increase again but to a lesser extent. IOP is more concentrated in front of the lens at around 1.13 MPa, less than the initial 5.66 MPa sustained upon shuttlecock impact. F, IOP distributes more posteriorly, and ciliary stress has now greatly dissipated. G, IOP continues to advance posteriorly down to the optic nerve head as ciliary stress also continues to decrease. IOP = intraocular pressure.