Risk of prion disease transmission from ocular donor tissue transplantation

Purpose. Recent new reports of possible iatrogenic transmission of Creutzfe ldt-Jakob disease (CJD) in Europe have prompted renewed scrutiny of current Eye Bank Association of America criteria for evaluation of potential corne al donors in this country. A prior study evaluated the risk of CSD occurrin g in U.S. corneal donors by using data to 1994. This report updates these d ata, analyses the risk by using data to 1997, and predicts potential risk i nto the next decade. Methods. EBAA data inclusive through 1997 were reviewe d and correlated with incidence figures for CJD in the United States as pro vided by the Communicable Disease Center in Atlanta. Results. The annual in cidence of CJD has remained stable at I case per million population. Thus s imilar to 270 new cases of CJD would be expected to occur each year in the United States. From this, the calculated risk of a prion-infected corneal d onor appearing in the donor pool is 0.045 cases per year. If the data are c orrected for age (90% of CJD patients are older than 60 years) and for poss ible infected but asymptomatic CJD patients (prevalence, 70 cases per milli on), at worst, 2.12 cases per year would appear for potential corneal donat ion (0.005% of all donors). Whereas donors completely without any neurologi c symptoms cannot be screened by using any currently available laboratory m ethod, those with a characteristic quadrate clinical prodrome including cog nitive changes, speech abnormalities, cerebellar findings, and myoclonus co uld all be potentially excluded by using tightened medical record and histo rical screening criteria. Although no cases of bovine spongiform encephalop athy (mad-cow disease) or new variant CJD have been reported in the United States, if such should occur, only 4.2 cases of CJD would be expected in po tential donors each year (0.009% of all donors). Tightening of exclusionary queries would significantly reduce the risk of even this number of patient s appearing for corneal donation. Conclusions. Historical queries of potent ial corneal donors should be tightened to assure exclusion of donors with e arly neurologic alterations. Any patient undergoing autopsy for evaluation of possible central nervous system (CNS) disease should be absolutely exclu ded. With this approach, the risk of inclusion of CTD-infected transplant t issues derived from ocular sources is very small, and all previously report ed cases would have been prospectively excluded from surgical use. Clearly, the benefits of corneal transplantation in the overall population continue significantly to outweigh the risks of transmission of prion disease.