Abstract
Purpose :
To evaluate the visual outcomes of myopic LASIK performed in thin corneas ≤ 540 μm using the Technolas 217z Excimer Laser (Baush & Lomb, Rochester, NY, US) with the Zyoptix Tissue Saving-2 ablation profile.
Methods :
Retrospective analysis of 102 myopic LASIK procedures (51 patients) by one experienced surgeon in which Technolas 217z (Baush & Lomb) and 120 micron corneal flap (Zyoptix XP microqueratome) were used following a standardized surgical technique. Inclusion criteria were patients >18 years with spherical equivalent refraction (SEQ) up to -8.5 diopters (D), cylinder up to 6.0 diopters (D), corrected visual acuity (CDVA) of 20/25 or better and a central corneal thickness (CCT) ≤ 540 μm. Flap thickness was intended for 120 µm and optical zone was between 5.5 and 6.0 mm. Standard visual outcomes analysis was performed. Tissue saving ablation profile was used to assure a minimum stromal bed of 300 µm.
Results :
Mean age was 26.52 ± 8.06 (range 18 to 55 years) with 54.9% female patients. Mean follow up was 13.9 ± 1.2 months. Preoperatively, CCT was 515.44±17.87 μm (range 452-540 μm). Mean SEQ was -4.01 ± 2.62 D (range -1.00 to -8.25 D) and mean cylinder was -1.38± 1.29 D (range 0.00 to -6.00 D). The mean predictability of postoperative SEQ was -0.21 ± 0.54 D (range -1.25 to +1.25). Postoperative SEQ was ±0.50 D in 69% and ±1.00 D in 93% of the eyes. Preoperative CDVA was 20/20 or better in 93% of the eyes. Postoperative uncorrected distance visual acuity was 20/20 or better in 84% and 20/25 or better 95%. One line of CDVA was lost in 3% of eyes and none of the eyes lost more than 2 lines of CDVA. No ectasia cases were observed during follow-up.
Conclusions :
Myopic LASIK performed on corneas with CCT ≤540 μm using the Zyoptix Tissue Saving-2 ablation profile is safe and efficient for the correction of up to -8.25 of SEQ of myopia and 6.0 diopters of cylinder without the need of a nomogram adjustment.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.