Thin-flap LASIK to increase the range of treatments using the NIDEK EC-5000 CX excimer laser

To compare the safety, advantages, and disadvantages of two LASIK groups that underwent surgery with a standard-thickness 130-microm microkeratome head (standard thickness group) and a 90-microm microkeratome head (thin flap group) prior to ablation with the NIDEK EC-5000 CX excimer laser.

Two hundred seventeen patients (420 eyes) with myopia or hyperopia underwent LASIK with either a 130-microm microkeratome head (137 eyes of 74 patients) or 90-microm microkeratome head (283 eyes of 143 patients). Corneal and stromal bed thickness prior to ablation were measured three consecutive times using ultrasound pachymetry. Averages of the corneal bed with the flap reflected, the flap thickness, and residual stromal bed were calculated for both groups. The postoperative appearance of the flaps and stroma in both groups were compared by slit-lamp examination.

No difference in preoperative corneal thickness was found between groups. Eyes that underwent treatment with the 130-microm microkeratome head had a mean flap thickness of 163.6 +/- 29.60 microm (range: 71 to 246 microm). Eyes that underwent treatment with the 90-microm microkeratome head had a mean flap thickness of 113.30 +/- 24.26 microm (range: 65 to 182 microm). No intra- or postoperative complications occurred in either group. Flap appearance was similar in both groups.

Both 130-microm and 90-microm microkeratome heads have similar predictability. Using a 90-microm microkeratome head leaves a thicker stromal bed for ablation.