The mean endothelial cell loss , including the rebubbled eyes , at the 12-month visit was 1093629 cells/mm2 ( range : 239-2109 cells/mm2 , mean percentage cell loss 41.2 % ) and 877566 cells/mm2 ( range : 116-1851 cells/mm2 , mean percentage cell loss 31.4 % ) in the Tan EndoGlide and EndoSerter groups , respectively ( P = .45 ) .