Sealed irrigation of the capsular bag after removal of the cataractous lens isolates the interior of the capsular bag from the anterior segment, permitting isolated targeting of lens epithelial cells (LECs) in vivo using pharmacologic agents while minimizing the risk of damage to other intraocular structures.
To assess the ability to deliver a nonspecific, extremely toxic agent (Triton X-100) directly to the LECs after crystalline lens removal, and to assess the eyes histologically for evidence of collateral damage.
Twelve eyes from 6 New Zealand White rabbits were divided into 3 groups of 4 eyes that underwent phacoaspiration of the crystalline lens. Group 1 was a control. In group 2, the anterior segment was irrigated with Triton X-100 and demineralized water for injection for 5 minutes. In group 3, the lens capsule was isolated from the anterior segment using sealed capsule irrigation (SCI) with PerfectCapsule (Milvella Pty Ltd, Sydney, Australia). After surgery, the rabbits were humanely euthanized. The enucleated eyes were immediately fixed in 10% neutral buffered formalin, histological analysis was performed to assess the corneal endothelium, iris, and retina, and the capsular bag and residual equatorial LECs were assessed.
The capsular bag was sealed and inflated under SCI in all treated eyes in group 3. Histological evaluation revealed no evidence of collateral damage in group 1 and group 3. Significant histological damage to the cornea, iris, and peripheral retina was noted in group 2. Histological evaluation of each capsular bag suggests presence of LECs in group 1 and group 2. In the presence of SCI, Triton X-100 caused almost complete destruction of LECs in the capsular bag.
Results suggest that SCI allows selective delivery of toxic agents directly into the capsular bag, preventing collateral damage to surrounding intraocular structures. The PerfectCapsule device kept the capsular bag well inflated intraoperatively, which may allow the isolated, safe delivery of pharmacologic agents into the capsular bag during cataract surgery.
Postoperative proliferation of LECs in the capsular bag remains the most frequent complication of cataract surgery. Unprotected intraocular infusion of cytotoxic drugs, antimetabolites, or hypo-osmotic agents during cataract surgery has the potential risk of causing toxic effects in corneal endothelium and adjacent intraocular tissues. Selective delivery of pharmacologic/hypo-osmotic agents into the capsular bag requires positive pressure inflation of the bag and is now possible using an SCI device. This device allows the surgeon to reseal the capsular bag intraoperatively, achieve positive pressure inflation of the capsular bag, and direct selective targeting of LECs.