Objective: To investigate the value of donor corneal rim cultures performed routinely at the time of penetrating keratoplasty.
Design: Retrospective review of Mayo Clinic medical records for all corneal transplantations for which donor rim cultures have been performed.
Main outcome measures: Frequency of positive cultures, occurrence of endophthalmitis within 2 months of undergoing surgery, action taken in response to the culture results, and costs of cultures.
Results: Donor rim culture results were available for 1078 of 1083 consecutive transplantations performed from 1981 to 1995. Three cases of endophthalmitis (0.28%) and 1 suture abscess occurred. Rim cultures were negative in all of these cases. Action was documented in response to positive cultures in 17 cases (8.1%). The estimated average cost of routine rim cultures in 1994 was $137 per donor cornea. Bacterial or fungal cultures were positive in 209 (19.4%) cases. Two microorganisms were cultured simultaneously in 17 cases (1.6%) and 3 in 2 cases (0.2%). Staphylococcus coagulase-negative (130 cases [12.1%]), and Streptococcus species, viridans group (23 cases [2.1%]), were the most common isolates. Fifty-two (62.7%) of 83 coagulase-negative Staphylococcus species isolates tested were resistant to gentamicin. There were more positive cultures from corneas stored in Optisol (37/183 [20%]) than in Optisol GS (16/144 [11%]) (P = .03). Fewer cultures were positive from live donors (9/93 [10%]) compared with cadaveric donors (181/ 909 [20%]) (P = .02). Positive cultures were more frequent for corneas excised in situ (39/125 [31.2%]) than for those enucleated (152/851 [17.9%]) (P < .001).
Conclusions: Despite differences in rates of positive donor rim cultures with different harvesting and storage techniques, for our practice, routine donor corneal rim cultures had no predictive value for infective complications of penetrating keratoplasty and, therefore, added an unnecessary expense to the management of our patients.