Safety Study to Examine the Use of Mitomycin-C, Distilled Water and Triton-X for Sealed Irrigation of the Capsular Bag to Prevent Posterior Capsule Opacification in Rabbits

Abstract

Abstract: : Purpose: Sealed irrigation of the capsular bag permits the use of toxic agents to eliminate lens epithelial cells whilst minimising the risk of collateral damage to other tissues. This safety study explored the use of a number of potentially toxic agents in the rabbit, which provides an aggressive model for posterior capsule opacification. Methods: Nine Albino New Zealand White rabbits underwent clear lens cataract extraction. A 4 mm capsulorrhexis was performed, the lens nucleus was expressed and soft lens matter removed using automated irrigation-aspiration. A sealed capsular chamber was then formed using the Perfect capsule^TM. The capsular bag was irrigated for 90 seconds with either Mitomycin-C (0.2 mg/ml), deionised distilled water +/- 1% triton-X (detergent) or balanced saline solution (control). After treatment the capsular bag was irrigated thoroughly with balanced saline solution. One eye was treated with mitomycin-C but the device was not sealed. This allowed escape of mitomycin-C into the anterior chamber and provided a positive control. Eyes were examined weekly for 6 weeks for conjunctival and anterior chamber inflammation and corneal clarity. At 6 weeks, the eyes were harvested and prepared for histological analysis. Results: There was no evidence of increased inflammation or decreased corneal clarity between control and treated eyes for all treatments at all timepoints. In the mitomycin-C treated positive control eye where no seal was applied, the eye became rapidly opaque with subsequent corneal neovascularization, and retrocorneal membrane with evidence of retinal damage. Conclusion: Sealed capsular irrigation appears safe in this rabbit model. Sealed capsular irrigation provides the opportunity for the use of a number of agents to eliminate LECs and prevent PCO formation whilst minimizing the risks of collateral damage.

Keywords: apoptosis/cell death • small incision cataract surgery