A recent study on the long-term outcomes of optical, therapeutic and tectonic forms of penetrating keratoplasty (PK) revealed that donor source plays a role in graft survival. The researchers conducted a prospective cohort study of all PKs performed from 1991 to 2010 at the Singapore National Eye Center. They included only primary grafts.

A total of 1,206 PKs were performed over the 20-year period. Patients’ ages ranged from <1 to 101, with most around 55 years. Over time, the researchers found that graft survival rate decreased (Table 1). They noted that the most common indications for optical grafts were pseudophakic bullous keratopathy, post-infectious corneal scarring/thinning and keratoconus. Compared with therapeutic and tectonic grafts, optical grafts performed significantly better at all time points in terms of survival.

The researchers concluded that allograft rejection and late endothelial failure were responsible for more than 60% of graft failures. Additionally, they noted that a younger donor age and high donor endothelial cell count were associated with better optical graft survival.