Anshu A, Li L, Htoon HM, et al. - Researchers conducted the study for analyzing the long-term outcomes of optical, therapeutic and tectonic forms of penetrating keratoplasty over a 20-year period in Asian eyes. Using records from the computerized database of the Singapore Corneal Transplant Study, all penetrating keratoplasties (PK) performed at the Singapore National Eye Centre from January 1991 to December 2010 were analyzed. One thousand two hundred six primary PKs were performed. Data reported that the overall corneal graft survival at 1, 5, 10, 15 and 20 years was 91%, 66.8%, 55.4%, 52% and 44% respectively. Over time, graft survival declined from 91% at 1 year to 44% at 20 years follow-up. More than 60% of graft failures were accounted for by allograft rejection and late endothelial failure.