Results-Several recipient factors influencing graft survival, rejection, and visual acuity were identified, but no donor factors. Of the operative factors amenable to change, mixed suturing was associated with reduced graft survival, and larger grafts with increased risk of rejection but better visual acuity when surviving. There was increased risk of rejection with poor matching at HLA class I antigens, but mismatched HLA-DR grafts suVered less rejection than those with zero HLA-DR mismatches. Recipient age below 10 years was associated with increased risk of both rejection and graft failure. However, whereas increasing age above 10 years was not associated with diVerential graft survival, it was significantly associated with decreasing risk of rejection. Conclusions-While confirming possible benefits of HLA-A and B matching, the expense and delay involved in awaiting matched HLA-DR tissue is unlikely to be justified. Other donor factors are unrelated to graft outcome following screening of tissue by eye banks. The highest rates of graft failure and rejection happen in the early postoperative period, and factors influencing visual outcome are also apparent at this stage.

The successful outcome of the majority of corneal transplants depends on the presence of a viable corneal endothelium. This monolayer of cells lines the inner surface of the cornea and its primary function is to maintain corneal transparency by controlling the hydration of the collagenous stromal layer. Since human corneal endothelial cells do not readily proliferate, preservation of the endothelium is a primary aim of methods of corneal storage. Although some cryopreserved corneas have been transplanted successfully, the complexity of the cryopreservation technique and its potential for causing endothelial damage have limited its application. Hypothermia (2–8°C) is the most commonly applied method of storage, which allows storage for 7–14 days. Organ culture (28–37°C), which extends storage time to 4 weeks, is used widely in European eye banks. Graft outcomes for corneas stored by these two techniques appear similar.

DALK had a higher overall failure rate than PK. The difference was largely accounted for by early failures, which appeared to be related to the surgeon's experience. DALK recipients were less likely to achieve BCVA of 6/6 than were PK recipients and were more likely to have -3 D or worse myopia.