*Laboratory of Experimental Pathology, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, †Goldshleger Eye Research Institute, Tel Aviv University, Tel Hashomer, Israel, and ‡Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel Abstract Purpose: Based on lessons learned from earlier attempts, a novel miniature glaucoma implant, Ex-PRESS, was developed in 1998. The current study summarizes the histopathologic evaluation o