An in vivo model of femtosecond laser intrastromal refractive surgery.

BACKGROUND AND OBJECTIVE To develop an animal model for evaluation of femtosecond laser intrastromal refractive surgery. METHODS Intrastromal photodisruption was performed in New Zealand Albino rabbits using a femtosecond laser system. This surgical pattern consisted of a 100 microm-tick pyramid of laser pulses starting 180 microm below the corneal surface. Animals underwent serial slit lamp examinations and corneal thickness measurements at 1,3,7,14, and 28 days, then monthly up to 1 year. RESULTS Approximately 70 microm of central corneal thinning were seen at 1 week, remaining stable up to 7 months. CONCLUSIONS Intrastromal photodisruption with femtosecond lasers produced consistent changes in corneal thickness without loss of corneal transparency. These changes were more stable than those produced with excimer laser procedures in a similar animal model.