Evaluation of Lens Capsule Stability Using Capsular Tension Ring, Iris Retractor, and Capsule Expander Using a Porcine Model With Zonular Dehiscence.

Purpose: We evaluate the efficacy of capsular tension rings (CTRs), iris retractors (IRs), and capsule expanders (CEs) in stabilizing the lens capsule under different degrees of zonular dehiscence using a porcine model.

Methods: We developed an experimental model that can be used to observe the dynamics of lens capsules with different degrees of zonular dehiscence during phacoemulsification and aspiration (PEA). PEA was performed without any aid (control) and with devices. A CTR was used for a dehiscence of 30°, 45°, 60°, 90°, 120°, 150°, and 180° and one to four IRs or one to three CEs were used for a dehiscence of 90°, 120°, and 180°. The retention rate, calculated as the area of the capsular bag during PEA divided by the area before zonular dissection, and the number of lens fragments dropped into the vitreous cavity during PEA were examined and compared among the control and experimental groups.

Results: The retention rate increased significantly with the use of devices compared to the control (P < 0.05). The number of dropped lens fragments decreased by one or less with the use of CTR, one IR, or one CE for 90°, two IRs, or one or two CEs for 120°, and three or four IRs, or two or three CEs for 180° of zonular dehiscence.

Conclusions: The experimental porcine eye model with zonular dehiscence makes it possible to observe the entire configuration of the lens capsule, and demonstrates differences in the efficacy of capsular bag retention with CTR, IR, and CE.