[Experimental investigation of postoperative use of medication in refractive surgery]

To harvest microorganisms from the microkeratome after LASIK. To induce experimental infectious keratitis and investigate the use of routine postoperative medication.

During eight consecutive days, we cultured the plate of the microkeratome after routine LASIK. Dilutions of the most frequent microorganism was prepared according to the MacFarland scale. Ten microliters were injected into both corneas of eight guinea pigs. The right cornea was used as control and the left cornea was treated with 0.3% ciprofloxacin associated with dexamethasone and ketorolac tromethamine every 4 hours for 24 hours (group 2). The animals were sacrificed and the corneas were divided into two halves, which were sent to analyzed by the microbiology and histopathology laboratory.

In the control group, Staphylococcus aureus could be retrieved from all corneas, while in group 2, only 50% showed positive cultures (p=0.0128). Histopathology concerning polymorphonuclear cells showed an intense degree of inflammation in group 1 (p=0.0203) and regarding monomorphonuclear cells, it was also more intense in group 1 (p=0.0051).

This study suggests that the use of wide-spectrum antibiotic associated with anti-inflammatory eye drops has a significant effect on the reduction of a potential infectious and inflammatory process after refractive surgery.