Comparison of Microbial Sampling Sites and Donor-Related Factors on Corneal Graft Contamination

Grafts used for corneal donation should be sterile to avoid transplantation failure and secondary infection. However, there are no clear and globally accepted specifications from eye banks on microbial sampling sites. The objective of this study was to analyze microbial contamination of corneal grafts collected from different sampling sites. We found that the contamination rates and strain compositions significantly differed at different sampling sites. To clarify the effect of the microbial sampling site on corneal graft contamination, microbial sampling was conducted using 30 corneal grafts at the extraocular and intraocular sides of the graft in 2020 from the National Eye Bank of Taiwan. Microbial contamination significantly differed (p < 0.05) between the different sampling sites on the graft according to McNemar’s test. Although the two sampling sites showed the same specificity (33.33%), the sensitivity of sampling on the extraocular side (82.35%) was higher than that on the intraocular side (17.65%) of the graft. Donor-associated factors, including the cause of death, operating place, and cold compression, were analyzed using chi-square statistics, which revealed no significant differences in microbial contamination. Thus, our data provide evidence for the microbial sampling site of donated grafts and clear specifications for maintaining the quality of corneal grafts.