Numerical simulations of experimental setups used for testing recent glaucoma drainage devices on the control of intraocular pressure abnormalities.

Commonly used glaucoma drainage devices (GDDs) have many disadvantageous circumstances especially in postoperative period. Researchers have investigated glaucoma drainage devices by in-vivo, ex-vivo and in-vitro experimental setups and tried to overcome their disadvantages. In this study, one branch of them, in-vitro experimental setups currently used in testing of GDDs are surveyed. Their disadvantages are discussed. As a result, a new innovative experimental setup is introduced. Then, its numerical simulations are performed using porous media approach in ANSYS Fluent for Ahmed and Molteno implants. Pressure losses of AGV at flow rates 2.5, 5, 10, 20, 25 μl/min are found as 693, 999.6, 1142.8, 1261.8, 1406.3, 1431.5 Pa respectively. Pressure Losses of single plate Molteno device at flow rates 9.1, 21.6, 34.7, 47, 60 are found as 669.6, 1326.3, 2014.9, 2658.2, 3338.5 Pa. Pressure Losses for double plate Molteno device at flow rates 5, 10, 15, 20, 25 μl/min are found as 547.6, 691.4, 835.4, 979.6, 1124 Pa. Geometric models of XEN and ExPress implants are simulated. Pressure loss of XEN implant at physiologic flow rate is found as 12.26 mmHg. Pressure losses of ExPress implant at flow rates 664, 1180, 1575, 1928, 2241 are found as 575.4, 1246.3, 1898, 2582.4, 3265.5. Lastly, CFD results are compared with experimental results in literature.