Flap dimensions created with the IntraLase FS laser

Purpose: To assess the safety and predictability of the IntraLase femtosecond laser to create accurate flap thickness and diameter. Setting. Clinical office-based practice. Methods: In the first 103 eyes in which flaps were created with the IntraLase laser, the flap thickness was measured by the ultrasonic difference between the preoperative and post-flap-creation central corneal thickness and the flap diameter was measured with calipers. Results. As the attempted flap thickness decreased from 140.0 mum to 110.0 mum in 10.0 mum increments, the mean flap thickness decreased from 132.5 mum to 125.0 mum, with standard deviations decreasing from +/-18.5 to +/-12.0 mum. The mean flap diameter differed from the attempted diameter by less than 0.03 mum in all but the 130.0 mum group. Two slipped flaps and 20 cases of interface inflammation occurred early in the series. Conclusions: The IntraLase laser, while adding technical complexity to the laser in situ keratomileusis procedure, is able to predictably create flap diameters, hinge location, and flap thickness while eliminating the risk for cap perforations. The technique of flap elevation affects rapidity of visual recovery.