Assessment of keratocyte activation following LASIK with flap creation using the IntraLase FS60 laser.

Purpose: To assess the response of corneal keratocytes to the IntraLase FS60 femtosecond laser using attenuated steroids.
Methods: Thirty patients (30 eyes) who underwent LASIK with the IntraLase FS60 were assessed by clinical examination and confocal microscopy 3 months postoperatively. Postoperative steroid regimen was Econopred Plus (Alcon Laboratories Inc) every hour for 1 day and four times daily for 7 days.
Results: No cornea had clinically significant flap interface haze. Two corneas had trace haze at the interface detected by slit-lamp examination; both showed significant keratocyte activation by confocal microscopy. Overall, some degree of keratocyte activation was detected at the flap interface in 10 of 30 eyes. The measured interface reflectivity was 328.8 +/- 85.0 confocal backscatter units (CBU) in eyes with activated keratocytes and 88.9 +/- 74.5 CBU for the remaining 19 eyes (P < .001).
Conclusions: With attenuated steroids, keratocyte activation was found in a significant number of eyes, although interface haze was subclinical. A higher steroid dosage might therefore be indicated.