Clinical Results of Wavefront-guided LASIK

PURPOSE: To investigate and compare the clinical outcomes of wavefront-guided LASIK performed by 2 different laser platforms. METHODS: A retrospective analysis of consecutive cases of eyes that underwent wavefront-guided LASIK by using the VISX S4 CustomVue system and the Zyoptix Z100 system advanced personalized mode. All procedures were performed by one surgeon. Fifty-six eyes of 36 patients were included. Of the 56 eyes, 30 eyes underwent LASIK by using the VISX S4 CustomVue system (CustomVue group), and other 26 eyes underwent LASIK by using the Zyoptix Z100 system (APT group). Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), manifest refraction, contrast sensitivity, total high order aberration (HOA), spherical aberration (SA) and Q-value were recorded preoperatively and at 1 week, 1 and 3 months postoperatively. RESULTS: There was no statistically significant difference between two groups in terms of preoperative UCVA, BCVA, manifest refraction, high order aberrations, Q-value and contrast sensitivity. Induced amount of SA was significantly lower in CustomVue group than in APT group (p = 0.02). CONCLUSIONS: Wavefront-guided LASIK performed by 2 different laser platforms caused clinically acceptable outcomes including good visual acuity and contrast sensitivity through 3 months. Furthermore, LASIK performed by VISX S4 CustomVue system caused less SA at three months after operation.

Comparison of the Flap Complication Rate Between Microkeratomes for LASIK

PURPOSE: To compare intraoperative and postoperative flap complication rate between the Hansatome Excellus and Zyoptix XP microkeratomes for LASIK surgery. METHODS: The intra- and post-operative flap complication rate, in 323 eyes of 167 patients operated on using the Hansatome microkeratome were compared with 260 eyes of 132 patients that were operated on using the Zyoptix XP microkeratome. RESULTS: The Hansatome group showed an intraoperative complication incidence of 2.7% compared to 0.4% for the Zyoptix XP group (p0.05). There was no incidence of visually significant complications in either group. CONCLUSIONS: The Zyoptix XP showed a significantly decreased intraoperative flap complication rate compared to the Hansatome Excellus microkeratome. The preoperative K value is an important factor for safe LASIK.

Clinical Evaluation of New Microkeratome

PURPOSE: To determine dimensions and quality of flaps created with Zyoptix(TM) XP microkeratome. METHODS: Ninety-nine eyes of 50 patients were enrolled in this prospective study. LASIK procedures were performed by a single surgeon, using Zyoptix(TM) XP microkeratomes (Bausch & Lomb) with 160 micrometer, 180 micrometer and 200 micrometer heads and suction rings with intended flap diameters (IFD) of 8.5 mm and 9.5 mm. Patients' age, preoperative manifest refraction value, keratometry reading, preoperative central corneal thickness, stromal bed thickness, and flap diameter were recorded. To calculate flap thickness, subtraction pachymetry was used. The microscopic quality of the flap and stromal bed was graded from 0 to 100. RESULTS: The mean thickness of flaps created by Zyoptix(TM) XP microkeratome was 107.56+/-13.61 micrometer with the 160 micrometer head, 132.99+/-21.03 micrometer with the 180 micrometer head, and 134.32+/-14.75 micrometer with the 200 micrometer head. The actual flap diameter was 9.18 mm for an IFD 8.5 mm and 9.96 mm for an IFD of 9.5 mm. Subjective assessment of the flap and stromal bed, respectively, was 98.32+/-2.24 and 97.94+/-3.85 with the 160 micrometer head, 97.86+/-1.73 and 97.97+/-2.22 with the 180 micrometer head, and 97.79+/-1.17 and 97.72+/-1.10 with the 200 micrometer head. CONCLUSIONS: Flaps created with Zyoptix(TM) XP microkertome were reproducible in their dimensions. The flaps and stromal beds were of high quality.