Stability of Laser Epithelial Keratomileusis with and without Mitomycin C Performed to Correct Myopia in Thin Corneas: A 15-Month Follow-up
Accepted 4 January 2008. published online 18 February 2008.
Purpose
To study the stability of the refraction 15 months after myopic laser epithelial keratomileusis (LASEK) performed in thin corneas with and without adjuvant mitomycin C (MMC).
Design
Retrospective review.
Methods
One hundred and thirty-six consecutive eyes that had undergone LASEK to correct their myopia and that had a preoperative central corneal thickness (CCT) of <500 μm at Vissum Madrid, Spain, were included. Intraoperative MMC was applied when the ablation depth exceeded 50 μm (49 eyes). We compared the residual refraction between the three- and 15-month examinations to detect a possible myopic change that would suggest secondary corneal ectasia.
Results
Mean preoperative CCT ± standard deviation (SD) was 484.4 ± 11.8 μm (range, 440 to 499 μm). Mean CCT ± SD three months after surgery was 417.9 ± 32.1 μm (range, 339 to 473 μm). Mean preoperative spherical refraction ± SD was −3.49 ± 2.10 diopters (D). Mean preoperative cylinder ± SD was −0.87 ± 1.20 D. The mean residual sphere ± SD was 0.15 ± 0.40 D three months after surgery and 0.11 ± 0.60 D 15 months after surgery (P = .45). The mean cylinder ± SD was −0.13 ± 0.30 D and −0.25 ± 0.50 D, respectively (P = .06). Both the uncorrected visual acuity (UCVA) and the best-spectacle corrected visual acuity (BSCVA) showed statistically significant improvement on the 15-month examination (P = .01 and P = .0001, respectively). When analyzed separately, the subgroup treated with intraoperative MMC also showed stability of the refraction and a statistically significant improvement both in UCVA and in BSCVA. Topography showed no signs of ectasia in any case.
Conclusions
Myopic LASEK performed on thin corneas, regardless of the use of intraoperative MMC, seems to obtain stable refractive results, with no sign of ectasia during a 15-month follow-up.
ABSTRACT