In situ ablation of lens epithelial cells in porcine eyes with the laser photolysis system

PURPOSE: To evaluate the efficacy of the laser photolysis system (LPS) (A.R.C. Laser GmbH) in removing lens epithelial cells (LECs) to prevent posterior capsule opacification (PCO) in an in situ model. SETTING: Department of Ophthalmology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany. METHODS: Twelve enucleated porcine eyes fixed in a specially developed eye holder were randomly assigned to the control or treatment group. The cornea and iris were removed from all eyes, and a small paracentral capsulorhexis was performed. The lens nucleus and cortex were extracted by hydroexpression. The tip of the LPS was inserted into the capsular bag of eyes in the treatment group, and 50 pulses (10 mJ) were applied to the anterior capsule. All capsules were evaluated for remaining LECs by confocal laser scanning microscopy (HRT II with the Rostock Cornea Module, Heidelberg Engineering) and standard histology (hematoxylin-eosin and periodic acid-Schiff stains). RESULTS: In the control group, a homogenous layer of LECs attached to the anterior capsule was seen with both evaluation methods. In the treatment group, no LECs adherent to the anterior capsule were detected, suggesting complete ablation of LECs from the capsule. Small islands of equatorial LECs were found in places in which the remaining cortical fibers protected cells from the laser shockwave. The results of the confocal laser scanning microscopy were confirmed by standard histology. CONCLUSIONS: The LPS completely ablated LECs in an in situ model of cataract extraction. This system might prevent formation of PCO in vivo.