[The investigation of microbial culturing of microkeratome blades and sponges used in laser in situ keratomileusis].

OBJECTIVE: The microbial culturing results were analysed from samples of the microkeratome blade and sponges in laser in situ keratomileusis (LASIK) procedures as for crossing the rational antibiotic eye drops for preventing infectious keratitis.

METHOD: In this prospective study, 106 microkeratome blades and 212 sponges were cultured in routine LASIK procedure, at Excimer laser center in Henan Eye Institute During March to April 2009. Positive cultures were then sent for routine sensitivities and the results were analysed.

RESULTS: 8 of the 106 blades were culturing positive, the positive rate was 7.55%. Each four positive cultures were in male and female patients. There was no statistical difference with gender (P = 1.000). 23 of the 212 sponges cultures were positive. The positive rate was 10.38%. All positive cultures grew Staphylococcus epidermidis. Twelve sponge positive cultures were in right eye and 11 were in left eye. There was no statistical difference between the right eye and left eye (P = 0.825). All of the 31 positive cultures were sensitive to gatifloxacin. The sensitivity of gatifloxacin, tobramycin, levofloxacin, ofloxacin, and ciprofloxacin were 100.00%, 96.77% (30/31), 93.55% (29/31), 90.32% (28/31) and 74.20% (23/31) respectively. All the patients have no infectious keratitis followed-up more then 6 monthes.

CONCLUSION: There could be positive cultures from samples of the microkeratome blade and sponges in routine LASIK procedures but no patients with positive cultures developed postoperative infectious keratitis. The main positive bacteria was Staphylococcus epidermidis. They are sensitive to third and the fourth-generation fluoroquinolones and tobramycin antibiotics. Pre and post-operative supply of sensitive antibiotics can prevent post-operative infection.