Abstract
Purpose: :
To investigate the effects of KM-5000D microkeratome for LASIK with ultra-thin flaps and to evaluate the clinical efficacy, safety and predictability of LASIK with ultra-thin flaps for extremely high myopia.
Methods: :
42 eyes of 26 cases with a spherical equivalent over -10 diopters were divided into two groups. 21 eyes of 14 cases received LASIK with ultra-thin flaps were included in group A. 21 eyes of 12 cases received LASEK were included in group B. The mean preoperative spherical equivalent was -14.23±2.28D and -12.85±2.28D respectively. Clinical efficacy and complications were observed and compared during and after surgery.
Results: :
The ultra-thin flap making by KM-5000D microkeratome was smooth and safe. There were no threatening complications for vision during surgery. The average flap thickness was 88.81±2.75µm. Postoperative visual acuity of group A recovered faster with less steroid use than of group B. Cornea was clear without haze in group A. There were different degrees of haze (0.5~1 grade) in group B. The residual spherical equivalent was -1.34±1.12D in group A and -1.34±1.12D in group B 3 months postoperatively. Spherical equivalent and uncorrected visual acuity of the two groups were significantly different before and after surgery (P<0.01). The rates of uncorrected visual acuity over 0.5 were 80.95% in group A and 90.48% in group B. No eye lost more than two lines of best-corrected visual acuity in both. Postoperative refraction ≤-2D and ≤-1D was 76.19% and 47.62% in group A, whereas 80.95% and 42.86% in group B. There was no significant difference between the groups (P>0.05).
Conclusions: :
KM-5000D microkeratome is fit for LASIK with ultra-thin corneal flaps. LASIK with ultra-thin corneal flaps for extremely high myopia is safe, effective and predictable. LASIK with ultra-thin corneal flaps may be better than LASEK. It needs further clinical study with larger scale and longer follow-up.
Keywords: refractive surgery: comparative studies • refractive surgery: LASIK • refractive surgery: other technologies