Prophylactic exposure of human corneal endothelial cells to Rho-associated kinase inhibitor reduced apoptosis rate after phacoemulsification: Ex vivo study.

PURPOSE: To evaluate whether prophylactic exposure of corneal endothelial cells (CECs) to a selective Rho-associated kinase (ROCK) inhibitor will inhibit CEC apoptosis after phacoemulsification.

SETTING

Laboratory evaluations at the Edith Wolfson Medical Center, Holon, Israel and the Chaim Sheba Medical Center, Tel-Hashomer, Ramat-Gan, Israel and the Chaim Sheba Medical Center, Tel-Hashomer, Ramat-Gan, Israel.

DESIGN

Experimental study.

METHOD: Human donor corneolimbal rings were divided into fragments that were stored in commercial storage media with or without the addition of 10 mM ROCK inhibitor for 1 week and were then exposed to phacoemulsification energy. Samples were dissociated into single cells by trypsin digestion and CECs were targeted using the antihuman CD166 antibody, a new biomarker. The CEC survival was evaluated for early and late apoptosis rate with flow cytometric analysis of annexin-V and propidium iodide (PI) double staining.

RESULTS

Six corneoscleral rings from 4 donors were studied. After phacoemulsification, CEC exposed to ROCK inhibitor demonstrated a 37.06% reduction in early apoptosis rate (29.36% ± 4.33% [SD] versus 46.65% ± 1.51%, P = .006) and 45.27% reduction in late apoptosis rate (17.6% ± 16.81% versus 32.16% ± 26.30%, P = .007), compared with controls. Subsequently, ROCK levels in apoptotic CECs were significantly lower in cells incubated with ROCK inhibitor than the control medium.

CONCLUSIONS

In this ex vivo study, ROCK inhibitor reduced endothelial loss and thus, could be used to limit or slow down CEC loss. Rho-associated kinase inhibitor might be used before cataract surgery, especially in high risk patients. This might be a promising new method for preventing pseudophakic bullous keratopathy.