Incidence of microbial infection after amniotic membrane transplantation

Objective: To report the incidence and characteristics of microbial infection following amniotic membrane transplantation (AMT). Methods: We retrieved the clinical and microbiological records of a total of 326 patients undergoing AMT from January 1994 to February 2001 at Bascom Palmer Eye Institute to determine the incidence and characteristics of post-AMT infections with respect to the interval between AMT and the time of microbial culturing, types of organisms, and clinical outcomes and to correlate these infections with the microbiologic results of AM storage media submitted immediately after AMT and the underlying ocular diagnosis. Results: We subdivided these 326 patients into two groups: 76 patients (from January 1994 to June 1998) used AM prepared from a research laboratory and did not submit AM storage media for culture under an Institutional Review Board-approved protocol, and 250 patients thereafter used AM obtained from a commercial source and routinely submitted AM storage media for culture. A total of 11 culture-positive infections (3.4%) were identified, and among them 7 infections (9.2%) were from the first group, and 4 (1.6%) were from the second group (P = 0.004). All 4 infections (5.2%) occurring within 1 month after AMT were exclusively from the first group (P = 0.003). All AM storage media from the second group were culture negative. Gram-positive organisms were the most frequent isolate (64%). infections were not correlated with the underlying ocular diagnosis. Conclusions: AMT is a safe method for ocular surface reconstruction with a very low rate of microbial infections, especially if AM is prepared according to Good Tissue Banking Practice set forth by FDA. Gram-positive isolates seem to be the most frequent isolates in infections after AMT.