LASEK with mitomycin C to correct myopia in thin corneas
Reviewed by Inderpaul Sian

This study evaluated the long-term outcomes of laser-assisted subepithelial keratomileusis (LASEK) with intraoperative use of mitomycin C (MMC) performed on thin corneas for the correction of myopia. MMC modulates the corneal wound healing response in surface healing, thus reducing the risk of postoperative corneal haze formation. This retrospective cohort study included 100 eyes with a preoperative central corneal thickness (CCT) thinner than 500μm that underwent LASEK + MMC with at least six years of follow-up. Stability of visual acuity and refraction and the efficacy, safety, and predictability at the examinations three months and the last annual postoperative visit were analysed. The ablation was performed with the Esiris excimer laser (Schwind eye tech). Preoperative CCT was 482.9±14.7μm (range: 433 to 499μm). Mean preoperative spherical equivalent was 4.09±2.3 diopters (D). At the three-month postoperative visit, mean CCT was 419.79±32.6μm. The residual spherical equivalent showed a statistically significant regression (P=.001) in the comparison between the three-month and the last annual postoperative visit. The efficacy index showed a significant decrease (P=.01) and the safety index remained stable around 0.96. Six or more years after the surgery, 85 eyes (85%) were within ±0.50D and 94 eyes (94%) eyes were within ±1.00D of emmetropia. The topography did not show signs of secondary corneal ectasia in any eye. They concluded that LASEK with intraoperative use of MMC seems to be safe, effective and predictable to correct myopia in corneas thinner than 500μm and with normal preoperative topography, providing good visual and refractive outcomes with no topographic signs of corneal ectasia in a mean 6.5 year follow-up. The limitation of this study is that the participants were not randomised, more studies with a larger number of cases and longer follow-up are needed to further clarify the maximum percent tissue altered and the minimum residual stroll bed thickness needed to avoid the risk of postoperative ectasia after surface ablation.

Long-term follow-up of LASEK with mitomycin C performed to correct myopia in thin corneas.
Garcia-Gonzalez M, Drake Rodriguez-Casanova P, Rodriguez-Perez I, et al.
JOURNAL OF REFRACTIVE SURGERY
2017;33(12):813-9.